SemaExprCXX.cpp revision 283526
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/// \file 11/// \brief Implements semantic analysis for C++ expressions. 12/// 13//===----------------------------------------------------------------------===// 14 15#include "clang/Sema/SemaInternal.h" 16#include "TreeTransform.h" 17#include "TypeLocBuilder.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/ASTLambda.h" 20#include "clang/AST/CXXInheritance.h" 21#include "clang/AST/CharUnits.h" 22#include "clang/AST/DeclObjC.h" 23#include "clang/AST/EvaluatedExprVisitor.h" 24#include "clang/AST/ExprCXX.h" 25#include "clang/AST/ExprObjC.h" 26#include "clang/AST/RecursiveASTVisitor.h" 27#include "clang/AST/TypeLoc.h" 28#include "clang/Basic/PartialDiagnostic.h" 29#include "clang/Basic/TargetInfo.h" 30#include "clang/Lex/Preprocessor.h" 31#include "clang/Sema/DeclSpec.h" 32#include "clang/Sema/Initialization.h" 33#include "clang/Sema/Lookup.h" 34#include "clang/Sema/ParsedTemplate.h" 35#include "clang/Sema/Scope.h" 36#include "clang/Sema/ScopeInfo.h" 37#include "clang/Sema/SemaLambda.h" 38#include "clang/Sema/TemplateDeduction.h" 39#include "llvm/ADT/APInt.h" 40#include "llvm/ADT/STLExtras.h" 41#include "llvm/Support/ErrorHandling.h" 42using namespace clang; 43using namespace sema; 44 45/// \brief Handle the result of the special case name lookup for inheriting 46/// constructor declarations. 'NS::X::X' and 'NS::X<...>::X' are treated as 47/// constructor names in member using declarations, even if 'X' is not the 48/// name of the corresponding type. 49ParsedType Sema::getInheritingConstructorName(CXXScopeSpec &SS, 50 SourceLocation NameLoc, 51 IdentifierInfo &Name) { 52 NestedNameSpecifier *NNS = SS.getScopeRep(); 53 54 // Convert the nested-name-specifier into a type. 55 QualType Type; 56 switch (NNS->getKind()) { 57 case NestedNameSpecifier::TypeSpec: 58 case NestedNameSpecifier::TypeSpecWithTemplate: 59 Type = QualType(NNS->getAsType(), 0); 60 break; 61 62 case NestedNameSpecifier::Identifier: 63 // Strip off the last layer of the nested-name-specifier and build a 64 // typename type for it. 65 assert(NNS->getAsIdentifier() == &Name && "not a constructor name"); 66 Type = Context.getDependentNameType(ETK_None, NNS->getPrefix(), 67 NNS->getAsIdentifier()); 68 break; 69 70 case NestedNameSpecifier::Global: 71 case NestedNameSpecifier::Super: 72 case NestedNameSpecifier::Namespace: 73 case NestedNameSpecifier::NamespaceAlias: 74 llvm_unreachable("Nested name specifier is not a type for inheriting ctor"); 75 } 76 77 // This reference to the type is located entirely at the location of the 78 // final identifier in the qualified-id. 79 return CreateParsedType(Type, 80 Context.getTrivialTypeSourceInfo(Type, NameLoc)); 81} 82 83ParsedType Sema::getDestructorName(SourceLocation TildeLoc, 84 IdentifierInfo &II, 85 SourceLocation NameLoc, 86 Scope *S, CXXScopeSpec &SS, 87 ParsedType ObjectTypePtr, 88 bool EnteringContext) { 89 // Determine where to perform name lookup. 90 91 // FIXME: This area of the standard is very messy, and the current 92 // wording is rather unclear about which scopes we search for the 93 // destructor name; see core issues 399 and 555. Issue 399 in 94 // particular shows where the current description of destructor name 95 // lookup is completely out of line with existing practice, e.g., 96 // this appears to be ill-formed: 97 // 98 // namespace N { 99 // template <typename T> struct S { 100 // ~S(); 101 // }; 102 // } 103 // 104 // void f(N::S<int>* s) { 105 // s->N::S<int>::~S(); 106 // } 107 // 108 // See also PR6358 and PR6359. 109 // For this reason, we're currently only doing the C++03 version of this 110 // code; the C++0x version has to wait until we get a proper spec. 111 QualType SearchType; 112 DeclContext *LookupCtx = nullptr; 113 bool isDependent = false; 114 bool LookInScope = false; 115 116 // If we have an object type, it's because we are in a 117 // pseudo-destructor-expression or a member access expression, and 118 // we know what type we're looking for. 119 if (ObjectTypePtr) 120 SearchType = GetTypeFromParser(ObjectTypePtr); 121 122 if (SS.isSet()) { 123 NestedNameSpecifier *NNS = SS.getScopeRep(); 124 125 bool AlreadySearched = false; 126 bool LookAtPrefix = true; 127 // C++11 [basic.lookup.qual]p6: 128 // If a pseudo-destructor-name (5.2.4) contains a nested-name-specifier, 129 // the type-names are looked up as types in the scope designated by the 130 // nested-name-specifier. Similarly, in a qualified-id of the form: 131 // 132 // nested-name-specifier[opt] class-name :: ~ class-name 133 // 134 // the second class-name is looked up in the same scope as the first. 135 // 136 // Here, we determine whether the code below is permitted to look at the 137 // prefix of the nested-name-specifier. 138 DeclContext *DC = computeDeclContext(SS, EnteringContext); 139 if (DC && DC->isFileContext()) { 140 AlreadySearched = true; 141 LookupCtx = DC; 142 isDependent = false; 143 } else if (DC && isa<CXXRecordDecl>(DC)) { 144 LookAtPrefix = false; 145 LookInScope = true; 146 } 147 148 // The second case from the C++03 rules quoted further above. 149 NestedNameSpecifier *Prefix = nullptr; 150 if (AlreadySearched) { 151 // Nothing left to do. 152 } else if (LookAtPrefix && (Prefix = NNS->getPrefix())) { 153 CXXScopeSpec PrefixSS; 154 PrefixSS.Adopt(NestedNameSpecifierLoc(Prefix, SS.location_data())); 155 LookupCtx = computeDeclContext(PrefixSS, EnteringContext); 156 isDependent = isDependentScopeSpecifier(PrefixSS); 157 } else if (ObjectTypePtr) { 158 LookupCtx = computeDeclContext(SearchType); 159 isDependent = SearchType->isDependentType(); 160 } else { 161 LookupCtx = computeDeclContext(SS, EnteringContext); 162 isDependent = LookupCtx && LookupCtx->isDependentContext(); 163 } 164 } else if (ObjectTypePtr) { 165 // C++ [basic.lookup.classref]p3: 166 // If the unqualified-id is ~type-name, the type-name is looked up 167 // in the context of the entire postfix-expression. If the type T 168 // of the object expression is of a class type C, the type-name is 169 // also looked up in the scope of class C. At least one of the 170 // lookups shall find a name that refers to (possibly 171 // cv-qualified) T. 172 LookupCtx = computeDeclContext(SearchType); 173 isDependent = SearchType->isDependentType(); 174 assert((isDependent || !SearchType->isIncompleteType()) && 175 "Caller should have completed object type"); 176 177 LookInScope = true; 178 } else { 179 // Perform lookup into the current scope (only). 180 LookInScope = true; 181 } 182 183 TypeDecl *NonMatchingTypeDecl = nullptr; 184 LookupResult Found(*this, &II, NameLoc, LookupOrdinaryName); 185 for (unsigned Step = 0; Step != 2; ++Step) { 186 // Look for the name first in the computed lookup context (if we 187 // have one) and, if that fails to find a match, in the scope (if 188 // we're allowed to look there). 189 Found.clear(); 190 if (Step == 0 && LookupCtx) 191 LookupQualifiedName(Found, LookupCtx); 192 else if (Step == 1 && LookInScope && S) 193 LookupName(Found, S); 194 else 195 continue; 196 197 // FIXME: Should we be suppressing ambiguities here? 198 if (Found.isAmbiguous()) 199 return ParsedType(); 200 201 if (TypeDecl *Type = Found.getAsSingle<TypeDecl>()) { 202 QualType T = Context.getTypeDeclType(Type); 203 MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false); 204 205 if (SearchType.isNull() || SearchType->isDependentType() || 206 Context.hasSameUnqualifiedType(T, SearchType)) { 207 // We found our type! 208 209 return CreateParsedType(T, 210 Context.getTrivialTypeSourceInfo(T, NameLoc)); 211 } 212 213 if (!SearchType.isNull()) 214 NonMatchingTypeDecl = Type; 215 } 216 217 // If the name that we found is a class template name, and it is 218 // the same name as the template name in the last part of the 219 // nested-name-specifier (if present) or the object type, then 220 // this is the destructor for that class. 221 // FIXME: This is a workaround until we get real drafting for core 222 // issue 399, for which there isn't even an obvious direction. 223 if (ClassTemplateDecl *Template = Found.getAsSingle<ClassTemplateDecl>()) { 224 QualType MemberOfType; 225 if (SS.isSet()) { 226 if (DeclContext *Ctx = computeDeclContext(SS, EnteringContext)) { 227 // Figure out the type of the context, if it has one. 228 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) 229 MemberOfType = Context.getTypeDeclType(Record); 230 } 231 } 232 if (MemberOfType.isNull()) 233 MemberOfType = SearchType; 234 235 if (MemberOfType.isNull()) 236 continue; 237 238 // We're referring into a class template specialization. If the 239 // class template we found is the same as the template being 240 // specialized, we found what we are looking for. 241 if (const RecordType *Record = MemberOfType->getAs<RecordType>()) { 242 if (ClassTemplateSpecializationDecl *Spec 243 = dyn_cast<ClassTemplateSpecializationDecl>(Record->getDecl())) { 244 if (Spec->getSpecializedTemplate()->getCanonicalDecl() == 245 Template->getCanonicalDecl()) 246 return CreateParsedType( 247 MemberOfType, 248 Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc)); 249 } 250 251 continue; 252 } 253 254 // We're referring to an unresolved class template 255 // specialization. Determine whether we class template we found 256 // is the same as the template being specialized or, if we don't 257 // know which template is being specialized, that it at least 258 // has the same name. 259 if (const TemplateSpecializationType *SpecType 260 = MemberOfType->getAs<TemplateSpecializationType>()) { 261 TemplateName SpecName = SpecType->getTemplateName(); 262 263 // The class template we found is the same template being 264 // specialized. 265 if (TemplateDecl *SpecTemplate = SpecName.getAsTemplateDecl()) { 266 if (SpecTemplate->getCanonicalDecl() == Template->getCanonicalDecl()) 267 return CreateParsedType( 268 MemberOfType, 269 Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc)); 270 271 continue; 272 } 273 274 // The class template we found has the same name as the 275 // (dependent) template name being specialized. 276 if (DependentTemplateName *DepTemplate 277 = SpecName.getAsDependentTemplateName()) { 278 if (DepTemplate->isIdentifier() && 279 DepTemplate->getIdentifier() == Template->getIdentifier()) 280 return CreateParsedType( 281 MemberOfType, 282 Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc)); 283 284 continue; 285 } 286 } 287 } 288 } 289 290 if (isDependent) { 291 // We didn't find our type, but that's okay: it's dependent 292 // anyway. 293 294 // FIXME: What if we have no nested-name-specifier? 295 QualType T = CheckTypenameType(ETK_None, SourceLocation(), 296 SS.getWithLocInContext(Context), 297 II, NameLoc); 298 return ParsedType::make(T); 299 } 300 301 if (NonMatchingTypeDecl) { 302 QualType T = Context.getTypeDeclType(NonMatchingTypeDecl); 303 Diag(NameLoc, diag::err_destructor_expr_type_mismatch) 304 << T << SearchType; 305 Diag(NonMatchingTypeDecl->getLocation(), diag::note_destructor_type_here) 306 << T; 307 } else if (ObjectTypePtr) 308 Diag(NameLoc, diag::err_ident_in_dtor_not_a_type) 309 << &II; 310 else { 311 SemaDiagnosticBuilder DtorDiag = Diag(NameLoc, 312 diag::err_destructor_class_name); 313 if (S) { 314 const DeclContext *Ctx = S->getEntity(); 315 if (const CXXRecordDecl *Class = dyn_cast_or_null<CXXRecordDecl>(Ctx)) 316 DtorDiag << FixItHint::CreateReplacement(SourceRange(NameLoc), 317 Class->getNameAsString()); 318 } 319 } 320 321 return ParsedType(); 322} 323 324ParsedType Sema::getDestructorType(const DeclSpec& DS, ParsedType ObjectType) { 325 if (DS.getTypeSpecType() == DeclSpec::TST_error || !ObjectType) 326 return ParsedType(); 327 assert(DS.getTypeSpecType() == DeclSpec::TST_decltype 328 && "only get destructor types from declspecs"); 329 QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc()); 330 QualType SearchType = GetTypeFromParser(ObjectType); 331 if (SearchType->isDependentType() || Context.hasSameUnqualifiedType(SearchType, T)) { 332 return ParsedType::make(T); 333 } 334 335 Diag(DS.getTypeSpecTypeLoc(), diag::err_destructor_expr_type_mismatch) 336 << T << SearchType; 337 return ParsedType(); 338} 339 340bool Sema::checkLiteralOperatorId(const CXXScopeSpec &SS, 341 const UnqualifiedId &Name) { 342 assert(Name.getKind() == UnqualifiedId::IK_LiteralOperatorId); 343 344 if (!SS.isValid()) 345 return false; 346 347 switch (SS.getScopeRep()->getKind()) { 348 case NestedNameSpecifier::Identifier: 349 case NestedNameSpecifier::TypeSpec: 350 case NestedNameSpecifier::TypeSpecWithTemplate: 351 // Per C++11 [over.literal]p2, literal operators can only be declared at 352 // namespace scope. Therefore, this unqualified-id cannot name anything. 353 // Reject it early, because we have no AST representation for this in the 354 // case where the scope is dependent. 355 Diag(Name.getLocStart(), diag::err_literal_operator_id_outside_namespace) 356 << SS.getScopeRep(); 357 return true; 358 359 case NestedNameSpecifier::Global: 360 case NestedNameSpecifier::Super: 361 case NestedNameSpecifier::Namespace: 362 case NestedNameSpecifier::NamespaceAlias: 363 return false; 364 } 365 366 llvm_unreachable("unknown nested name specifier kind"); 367} 368 369/// \brief Build a C++ typeid expression with a type operand. 370ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType, 371 SourceLocation TypeidLoc, 372 TypeSourceInfo *Operand, 373 SourceLocation RParenLoc) { 374 // C++ [expr.typeid]p4: 375 // The top-level cv-qualifiers of the lvalue expression or the type-id 376 // that is the operand of typeid are always ignored. 377 // If the type of the type-id is a class type or a reference to a class 378 // type, the class shall be completely-defined. 379 Qualifiers Quals; 380 QualType T 381 = Context.getUnqualifiedArrayType(Operand->getType().getNonReferenceType(), 382 Quals); 383 if (T->getAs<RecordType>() && 384 RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid)) 385 return ExprError(); 386 387 if (T->isVariablyModifiedType()) 388 return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid) << T); 389 390 return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), Operand, 391 SourceRange(TypeidLoc, RParenLoc)); 392} 393 394/// \brief Build a C++ typeid expression with an expression operand. 395ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType, 396 SourceLocation TypeidLoc, 397 Expr *E, 398 SourceLocation RParenLoc) { 399 bool WasEvaluated = false; 400 if (E && !E->isTypeDependent()) { 401 if (E->getType()->isPlaceholderType()) { 402 ExprResult result = CheckPlaceholderExpr(E); 403 if (result.isInvalid()) return ExprError(); 404 E = result.get(); 405 } 406 407 QualType T = E->getType(); 408 if (const RecordType *RecordT = T->getAs<RecordType>()) { 409 CXXRecordDecl *RecordD = cast<CXXRecordDecl>(RecordT->getDecl()); 410 // C++ [expr.typeid]p3: 411 // [...] If the type of the expression is a class type, the class 412 // shall be completely-defined. 413 if (RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid)) 414 return ExprError(); 415 416 // C++ [expr.typeid]p3: 417 // When typeid is applied to an expression other than an glvalue of a 418 // polymorphic class type [...] [the] expression is an unevaluated 419 // operand. [...] 420 if (RecordD->isPolymorphic() && E->isGLValue()) { 421 // The subexpression is potentially evaluated; switch the context 422 // and recheck the subexpression. 423 ExprResult Result = TransformToPotentiallyEvaluated(E); 424 if (Result.isInvalid()) return ExprError(); 425 E = Result.get(); 426 427 // We require a vtable to query the type at run time. 428 MarkVTableUsed(TypeidLoc, RecordD); 429 WasEvaluated = true; 430 } 431 } 432 433 // C++ [expr.typeid]p4: 434 // [...] If the type of the type-id is a reference to a possibly 435 // cv-qualified type, the result of the typeid expression refers to a 436 // std::type_info object representing the cv-unqualified referenced 437 // type. 438 Qualifiers Quals; 439 QualType UnqualT = Context.getUnqualifiedArrayType(T, Quals); 440 if (!Context.hasSameType(T, UnqualT)) { 441 T = UnqualT; 442 E = ImpCastExprToType(E, UnqualT, CK_NoOp, E->getValueKind()).get(); 443 } 444 } 445 446 if (E->getType()->isVariablyModifiedType()) 447 return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid) 448 << E->getType()); 449 else if (ActiveTemplateInstantiations.empty() && 450 E->HasSideEffects(Context, WasEvaluated)) { 451 // The expression operand for typeid is in an unevaluated expression 452 // context, so side effects could result in unintended consequences. 453 Diag(E->getExprLoc(), WasEvaluated 454 ? diag::warn_side_effects_typeid 455 : diag::warn_side_effects_unevaluated_context); 456 } 457 458 return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), E, 459 SourceRange(TypeidLoc, RParenLoc)); 460} 461 462/// ActOnCXXTypeidOfType - Parse typeid( type-id ) or typeid (expression); 463ExprResult 464Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc, 465 bool isType, void *TyOrExpr, SourceLocation RParenLoc) { 466 // Find the std::type_info type. 467 if (!getStdNamespace()) 468 return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid)); 469 470 if (!CXXTypeInfoDecl) { 471 IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info"); 472 LookupResult R(*this, TypeInfoII, SourceLocation(), LookupTagName); 473 LookupQualifiedName(R, getStdNamespace()); 474 CXXTypeInfoDecl = R.getAsSingle<RecordDecl>(); 475 // Microsoft's typeinfo doesn't have type_info in std but in the global 476 // namespace if _HAS_EXCEPTIONS is defined to 0. See PR13153. 477 if (!CXXTypeInfoDecl && LangOpts.MSVCCompat) { 478 LookupQualifiedName(R, Context.getTranslationUnitDecl()); 479 CXXTypeInfoDecl = R.getAsSingle<RecordDecl>(); 480 } 481 if (!CXXTypeInfoDecl) 482 return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid)); 483 } 484 485 if (!getLangOpts().RTTI) { 486 return ExprError(Diag(OpLoc, diag::err_no_typeid_with_fno_rtti)); 487 } 488 489 QualType TypeInfoType = Context.getTypeDeclType(CXXTypeInfoDecl); 490 491 if (isType) { 492 // The operand is a type; handle it as such. 493 TypeSourceInfo *TInfo = nullptr; 494 QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr), 495 &TInfo); 496 if (T.isNull()) 497 return ExprError(); 498 499 if (!TInfo) 500 TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc); 501 502 return BuildCXXTypeId(TypeInfoType, OpLoc, TInfo, RParenLoc); 503 } 504 505 // The operand is an expression. 506 return BuildCXXTypeId(TypeInfoType, OpLoc, (Expr*)TyOrExpr, RParenLoc); 507} 508 509/// \brief Build a Microsoft __uuidof expression with a type operand. 510ExprResult Sema::BuildCXXUuidof(QualType TypeInfoType, 511 SourceLocation TypeidLoc, 512 TypeSourceInfo *Operand, 513 SourceLocation RParenLoc) { 514 if (!Operand->getType()->isDependentType()) { 515 bool HasMultipleGUIDs = false; 516 if (!CXXUuidofExpr::GetUuidAttrOfType(Operand->getType(), 517 &HasMultipleGUIDs)) { 518 if (HasMultipleGUIDs) 519 return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids)); 520 else 521 return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid)); 522 } 523 } 524 525 return new (Context) CXXUuidofExpr(TypeInfoType.withConst(), Operand, 526 SourceRange(TypeidLoc, RParenLoc)); 527} 528 529/// \brief Build a Microsoft __uuidof expression with an expression operand. 530ExprResult Sema::BuildCXXUuidof(QualType TypeInfoType, 531 SourceLocation TypeidLoc, 532 Expr *E, 533 SourceLocation RParenLoc) { 534 if (!E->getType()->isDependentType()) { 535 bool HasMultipleGUIDs = false; 536 if (!CXXUuidofExpr::GetUuidAttrOfType(E->getType(), &HasMultipleGUIDs) && 537 !E->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 538 if (HasMultipleGUIDs) 539 return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids)); 540 else 541 return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid)); 542 } 543 } 544 545 return new (Context) CXXUuidofExpr(TypeInfoType.withConst(), E, 546 SourceRange(TypeidLoc, RParenLoc)); 547} 548 549/// ActOnCXXUuidof - Parse __uuidof( type-id ) or __uuidof (expression); 550ExprResult 551Sema::ActOnCXXUuidof(SourceLocation OpLoc, SourceLocation LParenLoc, 552 bool isType, void *TyOrExpr, SourceLocation RParenLoc) { 553 // If MSVCGuidDecl has not been cached, do the lookup. 554 if (!MSVCGuidDecl) { 555 IdentifierInfo *GuidII = &PP.getIdentifierTable().get("_GUID"); 556 LookupResult R(*this, GuidII, SourceLocation(), LookupTagName); 557 LookupQualifiedName(R, Context.getTranslationUnitDecl()); 558 MSVCGuidDecl = R.getAsSingle<RecordDecl>(); 559 if (!MSVCGuidDecl) 560 return ExprError(Diag(OpLoc, diag::err_need_header_before_ms_uuidof)); 561 } 562 563 QualType GuidType = Context.getTypeDeclType(MSVCGuidDecl); 564 565 if (isType) { 566 // The operand is a type; handle it as such. 567 TypeSourceInfo *TInfo = nullptr; 568 QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr), 569 &TInfo); 570 if (T.isNull()) 571 return ExprError(); 572 573 if (!TInfo) 574 TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc); 575 576 return BuildCXXUuidof(GuidType, OpLoc, TInfo, RParenLoc); 577 } 578 579 // The operand is an expression. 580 return BuildCXXUuidof(GuidType, OpLoc, (Expr*)TyOrExpr, RParenLoc); 581} 582 583/// ActOnCXXBoolLiteral - Parse {true,false} literals. 584ExprResult 585Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) { 586 assert((Kind == tok::kw_true || Kind == tok::kw_false) && 587 "Unknown C++ Boolean value!"); 588 return new (Context) 589 CXXBoolLiteralExpr(Kind == tok::kw_true, Context.BoolTy, OpLoc); 590} 591 592/// ActOnCXXNullPtrLiteral - Parse 'nullptr'. 593ExprResult 594Sema::ActOnCXXNullPtrLiteral(SourceLocation Loc) { 595 return new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc); 596} 597 598/// ActOnCXXThrow - Parse throw expressions. 599ExprResult 600Sema::ActOnCXXThrow(Scope *S, SourceLocation OpLoc, Expr *Ex) { 601 bool IsThrownVarInScope = false; 602 if (Ex) { 603 // C++0x [class.copymove]p31: 604 // When certain criteria are met, an implementation is allowed to omit the 605 // copy/move construction of a class object [...] 606 // 607 // - in a throw-expression, when the operand is the name of a 608 // non-volatile automatic object (other than a function or catch- 609 // clause parameter) whose scope does not extend beyond the end of the 610 // innermost enclosing try-block (if there is one), the copy/move 611 // operation from the operand to the exception object (15.1) can be 612 // omitted by constructing the automatic object directly into the 613 // exception object 614 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Ex->IgnoreParens())) 615 if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) { 616 if (Var->hasLocalStorage() && !Var->getType().isVolatileQualified()) { 617 for( ; S; S = S->getParent()) { 618 if (S->isDeclScope(Var)) { 619 IsThrownVarInScope = true; 620 break; 621 } 622 623 if (S->getFlags() & 624 (Scope::FnScope | Scope::ClassScope | Scope::BlockScope | 625 Scope::FunctionPrototypeScope | Scope::ObjCMethodScope | 626 Scope::TryScope)) 627 break; 628 } 629 } 630 } 631 } 632 633 return BuildCXXThrow(OpLoc, Ex, IsThrownVarInScope); 634} 635 636ExprResult Sema::BuildCXXThrow(SourceLocation OpLoc, Expr *Ex, 637 bool IsThrownVarInScope) { 638 // Don't report an error if 'throw' is used in system headers. 639 if (!getLangOpts().CXXExceptions && 640 !getSourceManager().isInSystemHeader(OpLoc)) 641 Diag(OpLoc, diag::err_exceptions_disabled) << "throw"; 642 643 if (getCurScope() && getCurScope()->isOpenMPSimdDirectiveScope()) 644 Diag(OpLoc, diag::err_omp_simd_region_cannot_use_stmt) << "throw"; 645 646 if (Ex && !Ex->isTypeDependent()) { 647 ExprResult ExRes = CheckCXXThrowOperand(OpLoc, Ex, IsThrownVarInScope); 648 if (ExRes.isInvalid()) 649 return ExprError(); 650 Ex = ExRes.get(); 651 } 652 653 return new (Context) 654 CXXThrowExpr(Ex, Context.VoidTy, OpLoc, IsThrownVarInScope); 655} 656 657/// CheckCXXThrowOperand - Validate the operand of a throw. 658ExprResult Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc, Expr *E, 659 bool IsThrownVarInScope) { 660 // C++ [except.throw]p3: 661 // A throw-expression initializes a temporary object, called the exception 662 // object, the type of which is determined by removing any top-level 663 // cv-qualifiers from the static type of the operand of throw and adjusting 664 // the type from "array of T" or "function returning T" to "pointer to T" 665 // or "pointer to function returning T", [...] 666 if (E->getType().hasQualifiers()) 667 E = ImpCastExprToType(E, E->getType().getUnqualifiedType(), CK_NoOp, 668 E->getValueKind()).get(); 669 670 ExprResult Res = DefaultFunctionArrayConversion(E); 671 if (Res.isInvalid()) 672 return ExprError(); 673 E = Res.get(); 674 675 // If the type of the exception would be an incomplete type or a pointer 676 // to an incomplete type other than (cv) void the program is ill-formed. 677 QualType Ty = E->getType(); 678 bool isPointer = false; 679 if (const PointerType* Ptr = Ty->getAs<PointerType>()) { 680 Ty = Ptr->getPointeeType(); 681 isPointer = true; 682 } 683 if (!isPointer || !Ty->isVoidType()) { 684 if (RequireCompleteType(ThrowLoc, Ty, 685 isPointer? diag::err_throw_incomplete_ptr 686 : diag::err_throw_incomplete, 687 E->getSourceRange())) 688 return ExprError(); 689 690 if (RequireNonAbstractType(ThrowLoc, E->getType(), 691 diag::err_throw_abstract_type, E)) 692 return ExprError(); 693 } 694 695 // Initialize the exception result. This implicitly weeds out 696 // abstract types or types with inaccessible copy constructors. 697 698 // C++0x [class.copymove]p31: 699 // When certain criteria are met, an implementation is allowed to omit the 700 // copy/move construction of a class object [...] 701 // 702 // - in a throw-expression, when the operand is the name of a 703 // non-volatile automatic object (other than a function or catch-clause 704 // parameter) whose scope does not extend beyond the end of the 705 // innermost enclosing try-block (if there is one), the copy/move 706 // operation from the operand to the exception object (15.1) can be 707 // omitted by constructing the automatic object directly into the 708 // exception object 709 const VarDecl *NRVOVariable = nullptr; 710 if (IsThrownVarInScope) 711 NRVOVariable = getCopyElisionCandidate(QualType(), E, false); 712 713 InitializedEntity Entity = 714 InitializedEntity::InitializeException(ThrowLoc, E->getType(), 715 /*NRVO=*/NRVOVariable != nullptr); 716 Res = PerformMoveOrCopyInitialization(Entity, NRVOVariable, 717 QualType(), E, 718 IsThrownVarInScope); 719 if (Res.isInvalid()) 720 return ExprError(); 721 E = Res.get(); 722 723 // If the exception has class type, we need additional handling. 724 const RecordType *RecordTy = Ty->getAs<RecordType>(); 725 if (!RecordTy) 726 return E; 727 CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl()); 728 729 // If we are throwing a polymorphic class type or pointer thereof, 730 // exception handling will make use of the vtable. 731 MarkVTableUsed(ThrowLoc, RD); 732 733 // If a pointer is thrown, the referenced object will not be destroyed. 734 if (isPointer) 735 return E; 736 737 // If the class has a destructor, we must be able to call it. 738 if (RD->hasIrrelevantDestructor()) 739 return E; 740 741 CXXDestructorDecl *Destructor = LookupDestructor(RD); 742 if (!Destructor) 743 return E; 744 745 MarkFunctionReferenced(E->getExprLoc(), Destructor); 746 CheckDestructorAccess(E->getExprLoc(), Destructor, 747 PDiag(diag::err_access_dtor_exception) << Ty); 748 if (DiagnoseUseOfDecl(Destructor, E->getExprLoc())) 749 return ExprError(); 750 return E; 751} 752 753QualType Sema::getCurrentThisType() { 754 DeclContext *DC = getFunctionLevelDeclContext(); 755 QualType ThisTy = CXXThisTypeOverride; 756 if (CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(DC)) { 757 if (method && method->isInstance()) 758 ThisTy = method->getThisType(Context); 759 } 760 if (ThisTy.isNull()) { 761 if (isGenericLambdaCallOperatorSpecialization(CurContext) && 762 CurContext->getParent()->getParent()->isRecord()) { 763 // This is a generic lambda call operator that is being instantiated 764 // within a default initializer - so use the enclosing class as 'this'. 765 // There is no enclosing member function to retrieve the 'this' pointer 766 // from. 767 QualType ClassTy = Context.getTypeDeclType( 768 cast<CXXRecordDecl>(CurContext->getParent()->getParent())); 769 // There are no cv-qualifiers for 'this' within default initializers, 770 // per [expr.prim.general]p4. 771 return Context.getPointerType(ClassTy); 772 } 773 } 774 return ThisTy; 775} 776 777Sema::CXXThisScopeRAII::CXXThisScopeRAII(Sema &S, 778 Decl *ContextDecl, 779 unsigned CXXThisTypeQuals, 780 bool Enabled) 781 : S(S), OldCXXThisTypeOverride(S.CXXThisTypeOverride), Enabled(false) 782{ 783 if (!Enabled || !ContextDecl) 784 return; 785 786 CXXRecordDecl *Record = nullptr; 787 if (ClassTemplateDecl *Template = dyn_cast<ClassTemplateDecl>(ContextDecl)) 788 Record = Template->getTemplatedDecl(); 789 else 790 Record = cast<CXXRecordDecl>(ContextDecl); 791 792 S.CXXThisTypeOverride 793 = S.Context.getPointerType( 794 S.Context.getRecordType(Record).withCVRQualifiers(CXXThisTypeQuals)); 795 796 this->Enabled = true; 797} 798 799 800Sema::CXXThisScopeRAII::~CXXThisScopeRAII() { 801 if (Enabled) { 802 S.CXXThisTypeOverride = OldCXXThisTypeOverride; 803 } 804} 805 806static Expr *captureThis(ASTContext &Context, RecordDecl *RD, 807 QualType ThisTy, SourceLocation Loc) { 808 FieldDecl *Field 809 = FieldDecl::Create(Context, RD, Loc, Loc, nullptr, ThisTy, 810 Context.getTrivialTypeSourceInfo(ThisTy, Loc), 811 nullptr, false, ICIS_NoInit); 812 Field->setImplicit(true); 813 Field->setAccess(AS_private); 814 RD->addDecl(Field); 815 return new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit*/true); 816} 817 818bool Sema::CheckCXXThisCapture(SourceLocation Loc, bool Explicit, 819 bool BuildAndDiagnose, const unsigned *const FunctionScopeIndexToStopAt) { 820 // We don't need to capture this in an unevaluated context. 821 if (isUnevaluatedContext() && !Explicit) 822 return true; 823 824 const unsigned MaxFunctionScopesIndex = FunctionScopeIndexToStopAt ? 825 *FunctionScopeIndexToStopAt : FunctionScopes.size() - 1; 826 // Otherwise, check that we can capture 'this'. 827 unsigned NumClosures = 0; 828 for (unsigned idx = MaxFunctionScopesIndex; idx != 0; idx--) { 829 if (CapturingScopeInfo *CSI = 830 dyn_cast<CapturingScopeInfo>(FunctionScopes[idx])) { 831 if (CSI->CXXThisCaptureIndex != 0) { 832 // 'this' is already being captured; there isn't anything more to do. 833 break; 834 } 835 LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI); 836 if (LSI && isGenericLambdaCallOperatorSpecialization(LSI->CallOperator)) { 837 // This context can't implicitly capture 'this'; fail out. 838 if (BuildAndDiagnose) 839 Diag(Loc, diag::err_this_capture) << Explicit; 840 return true; 841 } 842 if (CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByref || 843 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval || 844 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_Block || 845 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_CapturedRegion || 846 Explicit) { 847 // This closure can capture 'this'; continue looking upwards. 848 NumClosures++; 849 Explicit = false; 850 continue; 851 } 852 // This context can't implicitly capture 'this'; fail out. 853 if (BuildAndDiagnose) 854 Diag(Loc, diag::err_this_capture) << Explicit; 855 return true; 856 } 857 break; 858 } 859 if (!BuildAndDiagnose) return false; 860 // Mark that we're implicitly capturing 'this' in all the scopes we skipped. 861 // FIXME: We need to delay this marking in PotentiallyPotentiallyEvaluated 862 // contexts. 863 for (unsigned idx = MaxFunctionScopesIndex; NumClosures; 864 --idx, --NumClosures) { 865 CapturingScopeInfo *CSI = cast<CapturingScopeInfo>(FunctionScopes[idx]); 866 Expr *ThisExpr = nullptr; 867 QualType ThisTy = getCurrentThisType(); 868 if (LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI)) 869 // For lambda expressions, build a field and an initializing expression. 870 ThisExpr = captureThis(Context, LSI->Lambda, ThisTy, Loc); 871 else if (CapturedRegionScopeInfo *RSI 872 = dyn_cast<CapturedRegionScopeInfo>(FunctionScopes[idx])) 873 ThisExpr = captureThis(Context, RSI->TheRecordDecl, ThisTy, Loc); 874 875 bool isNested = NumClosures > 1; 876 CSI->addThisCapture(isNested, Loc, ThisTy, ThisExpr); 877 } 878 return false; 879} 880 881ExprResult Sema::ActOnCXXThis(SourceLocation Loc) { 882 /// C++ 9.3.2: In the body of a non-static member function, the keyword this 883 /// is a non-lvalue expression whose value is the address of the object for 884 /// which the function is called. 885 886 QualType ThisTy = getCurrentThisType(); 887 if (ThisTy.isNull()) return Diag(Loc, diag::err_invalid_this_use); 888 889 CheckCXXThisCapture(Loc); 890 return new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit=*/false); 891} 892 893bool Sema::isThisOutsideMemberFunctionBody(QualType BaseType) { 894 // If we're outside the body of a member function, then we'll have a specified 895 // type for 'this'. 896 if (CXXThisTypeOverride.isNull()) 897 return false; 898 899 // Determine whether we're looking into a class that's currently being 900 // defined. 901 CXXRecordDecl *Class = BaseType->getAsCXXRecordDecl(); 902 return Class && Class->isBeingDefined(); 903} 904 905ExprResult 906Sema::ActOnCXXTypeConstructExpr(ParsedType TypeRep, 907 SourceLocation LParenLoc, 908 MultiExprArg exprs, 909 SourceLocation RParenLoc) { 910 if (!TypeRep) 911 return ExprError(); 912 913 TypeSourceInfo *TInfo; 914 QualType Ty = GetTypeFromParser(TypeRep, &TInfo); 915 if (!TInfo) 916 TInfo = Context.getTrivialTypeSourceInfo(Ty, SourceLocation()); 917 918 return BuildCXXTypeConstructExpr(TInfo, LParenLoc, exprs, RParenLoc); 919} 920 921/// ActOnCXXTypeConstructExpr - Parse construction of a specified type. 922/// Can be interpreted either as function-style casting ("int(x)") 923/// or class type construction ("ClassType(x,y,z)") 924/// or creation of a value-initialized type ("int()"). 925ExprResult 926Sema::BuildCXXTypeConstructExpr(TypeSourceInfo *TInfo, 927 SourceLocation LParenLoc, 928 MultiExprArg Exprs, 929 SourceLocation RParenLoc) { 930 QualType Ty = TInfo->getType(); 931 SourceLocation TyBeginLoc = TInfo->getTypeLoc().getBeginLoc(); 932 933 if (Ty->isDependentType() || CallExpr::hasAnyTypeDependentArguments(Exprs)) { 934 return CXXUnresolvedConstructExpr::Create(Context, TInfo, LParenLoc, Exprs, 935 RParenLoc); 936 } 937 938 bool ListInitialization = LParenLoc.isInvalid(); 939 assert((!ListInitialization || (Exprs.size() == 1 && isa<InitListExpr>(Exprs[0]))) 940 && "List initialization must have initializer list as expression."); 941 SourceRange FullRange = SourceRange(TyBeginLoc, 942 ListInitialization ? Exprs[0]->getSourceRange().getEnd() : RParenLoc); 943 944 // C++ [expr.type.conv]p1: 945 // If the expression list is a single expression, the type conversion 946 // expression is equivalent (in definedness, and if defined in meaning) to the 947 // corresponding cast expression. 948 if (Exprs.size() == 1 && !ListInitialization) { 949 Expr *Arg = Exprs[0]; 950 return BuildCXXFunctionalCastExpr(TInfo, LParenLoc, Arg, RParenLoc); 951 } 952 953 QualType ElemTy = Ty; 954 if (Ty->isArrayType()) { 955 if (!ListInitialization) 956 return ExprError(Diag(TyBeginLoc, 957 diag::err_value_init_for_array_type) << FullRange); 958 ElemTy = Context.getBaseElementType(Ty); 959 } 960 961 if (!Ty->isVoidType() && 962 RequireCompleteType(TyBeginLoc, ElemTy, 963 diag::err_invalid_incomplete_type_use, FullRange)) 964 return ExprError(); 965 966 if (RequireNonAbstractType(TyBeginLoc, Ty, 967 diag::err_allocation_of_abstract_type)) 968 return ExprError(); 969 970 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TInfo); 971 InitializationKind Kind = 972 Exprs.size() ? ListInitialization 973 ? InitializationKind::CreateDirectList(TyBeginLoc) 974 : InitializationKind::CreateDirect(TyBeginLoc, LParenLoc, RParenLoc) 975 : InitializationKind::CreateValue(TyBeginLoc, LParenLoc, RParenLoc); 976 InitializationSequence InitSeq(*this, Entity, Kind, Exprs); 977 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Exprs); 978 979 if (Result.isInvalid() || !ListInitialization) 980 return Result; 981 982 Expr *Inner = Result.get(); 983 if (CXXBindTemporaryExpr *BTE = dyn_cast_or_null<CXXBindTemporaryExpr>(Inner)) 984 Inner = BTE->getSubExpr(); 985 if (isa<InitListExpr>(Inner)) { 986 // If the list-initialization doesn't involve a constructor call, we'll get 987 // the initializer-list (with corrected type) back, but that's not what we 988 // want, since it will be treated as an initializer list in further 989 // processing. Explicitly insert a cast here. 990 QualType ResultType = Result.get()->getType(); 991 Result = CXXFunctionalCastExpr::Create( 992 Context, ResultType, Expr::getValueKindForType(TInfo->getType()), TInfo, 993 CK_NoOp, Result.get(), /*Path=*/nullptr, LParenLoc, RParenLoc); 994 } 995 996 // FIXME: Improve AST representation? 997 return Result; 998} 999 1000/// doesUsualArrayDeleteWantSize - Answers whether the usual 1001/// operator delete[] for the given type has a size_t parameter. 1002static bool doesUsualArrayDeleteWantSize(Sema &S, SourceLocation loc, 1003 QualType allocType) { 1004 const RecordType *record = 1005 allocType->getBaseElementTypeUnsafe()->getAs<RecordType>(); 1006 if (!record) return false; 1007 1008 // Try to find an operator delete[] in class scope. 1009 1010 DeclarationName deleteName = 1011 S.Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete); 1012 LookupResult ops(S, deleteName, loc, Sema::LookupOrdinaryName); 1013 S.LookupQualifiedName(ops, record->getDecl()); 1014 1015 // We're just doing this for information. 1016 ops.suppressDiagnostics(); 1017 1018 // Very likely: there's no operator delete[]. 1019 if (ops.empty()) return false; 1020 1021 // If it's ambiguous, it should be illegal to call operator delete[] 1022 // on this thing, so it doesn't matter if we allocate extra space or not. 1023 if (ops.isAmbiguous()) return false; 1024 1025 LookupResult::Filter filter = ops.makeFilter(); 1026 while (filter.hasNext()) { 1027 NamedDecl *del = filter.next()->getUnderlyingDecl(); 1028 1029 // C++0x [basic.stc.dynamic.deallocation]p2: 1030 // A template instance is never a usual deallocation function, 1031 // regardless of its signature. 1032 if (isa<FunctionTemplateDecl>(del)) { 1033 filter.erase(); 1034 continue; 1035 } 1036 1037 // C++0x [basic.stc.dynamic.deallocation]p2: 1038 // If class T does not declare [an operator delete[] with one 1039 // parameter] but does declare a member deallocation function 1040 // named operator delete[] with exactly two parameters, the 1041 // second of which has type std::size_t, then this function 1042 // is a usual deallocation function. 1043 if (!cast<CXXMethodDecl>(del)->isUsualDeallocationFunction()) { 1044 filter.erase(); 1045 continue; 1046 } 1047 } 1048 filter.done(); 1049 1050 if (!ops.isSingleResult()) return false; 1051 1052 const FunctionDecl *del = cast<FunctionDecl>(ops.getFoundDecl()); 1053 return (del->getNumParams() == 2); 1054} 1055 1056/// \brief Parsed a C++ 'new' expression (C++ 5.3.4). 1057/// 1058/// E.g.: 1059/// @code new (memory) int[size][4] @endcode 1060/// or 1061/// @code ::new Foo(23, "hello") @endcode 1062/// 1063/// \param StartLoc The first location of the expression. 1064/// \param UseGlobal True if 'new' was prefixed with '::'. 1065/// \param PlacementLParen Opening paren of the placement arguments. 1066/// \param PlacementArgs Placement new arguments. 1067/// \param PlacementRParen Closing paren of the placement arguments. 1068/// \param TypeIdParens If the type is in parens, the source range. 1069/// \param D The type to be allocated, as well as array dimensions. 1070/// \param Initializer The initializing expression or initializer-list, or null 1071/// if there is none. 1072ExprResult 1073Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal, 1074 SourceLocation PlacementLParen, MultiExprArg PlacementArgs, 1075 SourceLocation PlacementRParen, SourceRange TypeIdParens, 1076 Declarator &D, Expr *Initializer) { 1077 bool TypeContainsAuto = D.getDeclSpec().containsPlaceholderType(); 1078 1079 Expr *ArraySize = nullptr; 1080 // If the specified type is an array, unwrap it and save the expression. 1081 if (D.getNumTypeObjects() > 0 && 1082 D.getTypeObject(0).Kind == DeclaratorChunk::Array) { 1083 DeclaratorChunk &Chunk = D.getTypeObject(0); 1084 if (TypeContainsAuto) 1085 return ExprError(Diag(Chunk.Loc, diag::err_new_array_of_auto) 1086 << D.getSourceRange()); 1087 if (Chunk.Arr.hasStatic) 1088 return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new) 1089 << D.getSourceRange()); 1090 if (!Chunk.Arr.NumElts) 1091 return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size) 1092 << D.getSourceRange()); 1093 1094 ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts); 1095 D.DropFirstTypeObject(); 1096 } 1097 1098 // Every dimension shall be of constant size. 1099 if (ArraySize) { 1100 for (unsigned I = 0, N = D.getNumTypeObjects(); I < N; ++I) { 1101 if (D.getTypeObject(I).Kind != DeclaratorChunk::Array) 1102 break; 1103 1104 DeclaratorChunk::ArrayTypeInfo &Array = D.getTypeObject(I).Arr; 1105 if (Expr *NumElts = (Expr *)Array.NumElts) { 1106 if (!NumElts->isTypeDependent() && !NumElts->isValueDependent()) { 1107 if (getLangOpts().CPlusPlus14) { 1108 // C++1y [expr.new]p6: Every constant-expression in a noptr-new-declarator 1109 // shall be a converted constant expression (5.19) of type std::size_t 1110 // and shall evaluate to a strictly positive value. 1111 unsigned IntWidth = Context.getTargetInfo().getIntWidth(); 1112 assert(IntWidth && "Builtin type of size 0?"); 1113 llvm::APSInt Value(IntWidth); 1114 Array.NumElts 1115 = CheckConvertedConstantExpression(NumElts, Context.getSizeType(), Value, 1116 CCEK_NewExpr) 1117 .get(); 1118 } else { 1119 Array.NumElts 1120 = VerifyIntegerConstantExpression(NumElts, nullptr, 1121 diag::err_new_array_nonconst) 1122 .get(); 1123 } 1124 if (!Array.NumElts) 1125 return ExprError(); 1126 } 1127 } 1128 } 1129 } 1130 1131 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, /*Scope=*/nullptr); 1132 QualType AllocType = TInfo->getType(); 1133 if (D.isInvalidType()) 1134 return ExprError(); 1135 1136 SourceRange DirectInitRange; 1137 if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) 1138 DirectInitRange = List->getSourceRange(); 1139 1140 return BuildCXXNew(SourceRange(StartLoc, D.getLocEnd()), UseGlobal, 1141 PlacementLParen, 1142 PlacementArgs, 1143 PlacementRParen, 1144 TypeIdParens, 1145 AllocType, 1146 TInfo, 1147 ArraySize, 1148 DirectInitRange, 1149 Initializer, 1150 TypeContainsAuto); 1151} 1152 1153static bool isLegalArrayNewInitializer(CXXNewExpr::InitializationStyle Style, 1154 Expr *Init) { 1155 if (!Init) 1156 return true; 1157 if (ParenListExpr *PLE = dyn_cast<ParenListExpr>(Init)) 1158 return PLE->getNumExprs() == 0; 1159 if (isa<ImplicitValueInitExpr>(Init)) 1160 return true; 1161 else if (CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init)) 1162 return !CCE->isListInitialization() && 1163 CCE->getConstructor()->isDefaultConstructor(); 1164 else if (Style == CXXNewExpr::ListInit) { 1165 assert(isa<InitListExpr>(Init) && 1166 "Shouldn't create list CXXConstructExprs for arrays."); 1167 return true; 1168 } 1169 return false; 1170} 1171 1172ExprResult 1173Sema::BuildCXXNew(SourceRange Range, bool UseGlobal, 1174 SourceLocation PlacementLParen, 1175 MultiExprArg PlacementArgs, 1176 SourceLocation PlacementRParen, 1177 SourceRange TypeIdParens, 1178 QualType AllocType, 1179 TypeSourceInfo *AllocTypeInfo, 1180 Expr *ArraySize, 1181 SourceRange DirectInitRange, 1182 Expr *Initializer, 1183 bool TypeMayContainAuto) { 1184 SourceRange TypeRange = AllocTypeInfo->getTypeLoc().getSourceRange(); 1185 SourceLocation StartLoc = Range.getBegin(); 1186 1187 CXXNewExpr::InitializationStyle initStyle; 1188 if (DirectInitRange.isValid()) { 1189 assert(Initializer && "Have parens but no initializer."); 1190 initStyle = CXXNewExpr::CallInit; 1191 } else if (Initializer && isa<InitListExpr>(Initializer)) 1192 initStyle = CXXNewExpr::ListInit; 1193 else { 1194 assert((!Initializer || isa<ImplicitValueInitExpr>(Initializer) || 1195 isa<CXXConstructExpr>(Initializer)) && 1196 "Initializer expression that cannot have been implicitly created."); 1197 initStyle = CXXNewExpr::NoInit; 1198 } 1199 1200 Expr **Inits = &Initializer; 1201 unsigned NumInits = Initializer ? 1 : 0; 1202 if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) { 1203 assert(initStyle == CXXNewExpr::CallInit && "paren init for non-call init"); 1204 Inits = List->getExprs(); 1205 NumInits = List->getNumExprs(); 1206 } 1207 1208 // C++11 [dcl.spec.auto]p6. Deduce the type which 'auto' stands in for. 1209 if (TypeMayContainAuto && AllocType->isUndeducedType()) { 1210 if (initStyle == CXXNewExpr::NoInit || NumInits == 0) 1211 return ExprError(Diag(StartLoc, diag::err_auto_new_requires_ctor_arg) 1212 << AllocType << TypeRange); 1213 if (initStyle == CXXNewExpr::ListInit || 1214 (NumInits == 1 && isa<InitListExpr>(Inits[0]))) 1215 return ExprError(Diag(Inits[0]->getLocStart(), 1216 diag::err_auto_new_list_init) 1217 << AllocType << TypeRange); 1218 if (NumInits > 1) { 1219 Expr *FirstBad = Inits[1]; 1220 return ExprError(Diag(FirstBad->getLocStart(), 1221 diag::err_auto_new_ctor_multiple_expressions) 1222 << AllocType << TypeRange); 1223 } 1224 Expr *Deduce = Inits[0]; 1225 QualType DeducedType; 1226 if (DeduceAutoType(AllocTypeInfo, Deduce, DeducedType) == DAR_Failed) 1227 return ExprError(Diag(StartLoc, diag::err_auto_new_deduction_failure) 1228 << AllocType << Deduce->getType() 1229 << TypeRange << Deduce->getSourceRange()); 1230 if (DeducedType.isNull()) 1231 return ExprError(); 1232 AllocType = DeducedType; 1233 } 1234 1235 // Per C++0x [expr.new]p5, the type being constructed may be a 1236 // typedef of an array type. 1237 if (!ArraySize) { 1238 if (const ConstantArrayType *Array 1239 = Context.getAsConstantArrayType(AllocType)) { 1240 ArraySize = IntegerLiteral::Create(Context, Array->getSize(), 1241 Context.getSizeType(), 1242 TypeRange.getEnd()); 1243 AllocType = Array->getElementType(); 1244 } 1245 } 1246 1247 if (CheckAllocatedType(AllocType, TypeRange.getBegin(), TypeRange)) 1248 return ExprError(); 1249 1250 if (initStyle == CXXNewExpr::ListInit && 1251 isStdInitializerList(AllocType, nullptr)) { 1252 Diag(AllocTypeInfo->getTypeLoc().getBeginLoc(), 1253 diag::warn_dangling_std_initializer_list) 1254 << /*at end of FE*/0 << Inits[0]->getSourceRange(); 1255 } 1256 1257 // In ARC, infer 'retaining' for the allocated 1258 if (getLangOpts().ObjCAutoRefCount && 1259 AllocType.getObjCLifetime() == Qualifiers::OCL_None && 1260 AllocType->isObjCLifetimeType()) { 1261 AllocType = Context.getLifetimeQualifiedType(AllocType, 1262 AllocType->getObjCARCImplicitLifetime()); 1263 } 1264 1265 QualType ResultType = Context.getPointerType(AllocType); 1266 1267 if (ArraySize && ArraySize->getType()->isNonOverloadPlaceholderType()) { 1268 ExprResult result = CheckPlaceholderExpr(ArraySize); 1269 if (result.isInvalid()) return ExprError(); 1270 ArraySize = result.get(); 1271 } 1272 // C++98 5.3.4p6: "The expression in a direct-new-declarator shall have 1273 // integral or enumeration type with a non-negative value." 1274 // C++11 [expr.new]p6: The expression [...] shall be of integral or unscoped 1275 // enumeration type, or a class type for which a single non-explicit 1276 // conversion function to integral or unscoped enumeration type exists. 1277 // C++1y [expr.new]p6: The expression [...] is implicitly converted to 1278 // std::size_t. 1279 if (ArraySize && !ArraySize->isTypeDependent()) { 1280 ExprResult ConvertedSize; 1281 if (getLangOpts().CPlusPlus14) { 1282 assert(Context.getTargetInfo().getIntWidth() && "Builtin type of size 0?"); 1283 1284 ConvertedSize = PerformImplicitConversion(ArraySize, Context.getSizeType(), 1285 AA_Converting); 1286 1287 if (!ConvertedSize.isInvalid() && 1288 ArraySize->getType()->getAs<RecordType>()) 1289 // Diagnose the compatibility of this conversion. 1290 Diag(StartLoc, diag::warn_cxx98_compat_array_size_conversion) 1291 << ArraySize->getType() << 0 << "'size_t'"; 1292 } else { 1293 class SizeConvertDiagnoser : public ICEConvertDiagnoser { 1294 protected: 1295 Expr *ArraySize; 1296 1297 public: 1298 SizeConvertDiagnoser(Expr *ArraySize) 1299 : ICEConvertDiagnoser(/*AllowScopedEnumerations*/false, false, false), 1300 ArraySize(ArraySize) {} 1301 1302 SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc, 1303 QualType T) override { 1304 return S.Diag(Loc, diag::err_array_size_not_integral) 1305 << S.getLangOpts().CPlusPlus11 << T; 1306 } 1307 1308 SemaDiagnosticBuilder diagnoseIncomplete( 1309 Sema &S, SourceLocation Loc, QualType T) override { 1310 return S.Diag(Loc, diag::err_array_size_incomplete_type) 1311 << T << ArraySize->getSourceRange(); 1312 } 1313 1314 SemaDiagnosticBuilder diagnoseExplicitConv( 1315 Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override { 1316 return S.Diag(Loc, diag::err_array_size_explicit_conversion) << T << ConvTy; 1317 } 1318 1319 SemaDiagnosticBuilder noteExplicitConv( 1320 Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override { 1321 return S.Diag(Conv->getLocation(), diag::note_array_size_conversion) 1322 << ConvTy->isEnumeralType() << ConvTy; 1323 } 1324 1325 SemaDiagnosticBuilder diagnoseAmbiguous( 1326 Sema &S, SourceLocation Loc, QualType T) override { 1327 return S.Diag(Loc, diag::err_array_size_ambiguous_conversion) << T; 1328 } 1329 1330 SemaDiagnosticBuilder noteAmbiguous( 1331 Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override { 1332 return S.Diag(Conv->getLocation(), diag::note_array_size_conversion) 1333 << ConvTy->isEnumeralType() << ConvTy; 1334 } 1335 1336 virtual SemaDiagnosticBuilder diagnoseConversion( 1337 Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override { 1338 return S.Diag(Loc, 1339 S.getLangOpts().CPlusPlus11 1340 ? diag::warn_cxx98_compat_array_size_conversion 1341 : diag::ext_array_size_conversion) 1342 << T << ConvTy->isEnumeralType() << ConvTy; 1343 } 1344 } SizeDiagnoser(ArraySize); 1345 1346 ConvertedSize = PerformContextualImplicitConversion(StartLoc, ArraySize, 1347 SizeDiagnoser); 1348 } 1349 if (ConvertedSize.isInvalid()) 1350 return ExprError(); 1351 1352 ArraySize = ConvertedSize.get(); 1353 QualType SizeType = ArraySize->getType(); 1354 1355 if (!SizeType->isIntegralOrUnscopedEnumerationType()) 1356 return ExprError(); 1357 1358 // C++98 [expr.new]p7: 1359 // The expression in a direct-new-declarator shall have integral type 1360 // with a non-negative value. 1361 // 1362 // Let's see if this is a constant < 0. If so, we reject it out of 1363 // hand. Otherwise, if it's not a constant, we must have an unparenthesized 1364 // array type. 1365 // 1366 // Note: such a construct has well-defined semantics in C++11: it throws 1367 // std::bad_array_new_length. 1368 if (!ArraySize->isValueDependent()) { 1369 llvm::APSInt Value; 1370 // We've already performed any required implicit conversion to integer or 1371 // unscoped enumeration type. 1372 if (ArraySize->isIntegerConstantExpr(Value, Context)) { 1373 if (Value < llvm::APSInt( 1374 llvm::APInt::getNullValue(Value.getBitWidth()), 1375 Value.isUnsigned())) { 1376 if (getLangOpts().CPlusPlus11) 1377 Diag(ArraySize->getLocStart(), 1378 diag::warn_typecheck_negative_array_new_size) 1379 << ArraySize->getSourceRange(); 1380 else 1381 return ExprError(Diag(ArraySize->getLocStart(), 1382 diag::err_typecheck_negative_array_size) 1383 << ArraySize->getSourceRange()); 1384 } else if (!AllocType->isDependentType()) { 1385 unsigned ActiveSizeBits = 1386 ConstantArrayType::getNumAddressingBits(Context, AllocType, Value); 1387 if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) { 1388 if (getLangOpts().CPlusPlus11) 1389 Diag(ArraySize->getLocStart(), 1390 diag::warn_array_new_too_large) 1391 << Value.toString(10) 1392 << ArraySize->getSourceRange(); 1393 else 1394 return ExprError(Diag(ArraySize->getLocStart(), 1395 diag::err_array_too_large) 1396 << Value.toString(10) 1397 << ArraySize->getSourceRange()); 1398 } 1399 } 1400 } else if (TypeIdParens.isValid()) { 1401 // Can't have dynamic array size when the type-id is in parentheses. 1402 Diag(ArraySize->getLocStart(), diag::ext_new_paren_array_nonconst) 1403 << ArraySize->getSourceRange() 1404 << FixItHint::CreateRemoval(TypeIdParens.getBegin()) 1405 << FixItHint::CreateRemoval(TypeIdParens.getEnd()); 1406 1407 TypeIdParens = SourceRange(); 1408 } 1409 } 1410 1411 // Note that we do *not* convert the argument in any way. It can 1412 // be signed, larger than size_t, whatever. 1413 } 1414 1415 FunctionDecl *OperatorNew = nullptr; 1416 FunctionDecl *OperatorDelete = nullptr; 1417 1418 if (!AllocType->isDependentType() && 1419 !Expr::hasAnyTypeDependentArguments(PlacementArgs) && 1420 FindAllocationFunctions(StartLoc, 1421 SourceRange(PlacementLParen, PlacementRParen), 1422 UseGlobal, AllocType, ArraySize, PlacementArgs, 1423 OperatorNew, OperatorDelete)) 1424 return ExprError(); 1425 1426 // If this is an array allocation, compute whether the usual array 1427 // deallocation function for the type has a size_t parameter. 1428 bool UsualArrayDeleteWantsSize = false; 1429 if (ArraySize && !AllocType->isDependentType()) 1430 UsualArrayDeleteWantsSize 1431 = doesUsualArrayDeleteWantSize(*this, StartLoc, AllocType); 1432 1433 SmallVector<Expr *, 8> AllPlaceArgs; 1434 if (OperatorNew) { 1435 const FunctionProtoType *Proto = 1436 OperatorNew->getType()->getAs<FunctionProtoType>(); 1437 VariadicCallType CallType = Proto->isVariadic() ? VariadicFunction 1438 : VariadicDoesNotApply; 1439 1440 // We've already converted the placement args, just fill in any default 1441 // arguments. Skip the first parameter because we don't have a corresponding 1442 // argument. 1443 if (GatherArgumentsForCall(PlacementLParen, OperatorNew, Proto, 1, 1444 PlacementArgs, AllPlaceArgs, CallType)) 1445 return ExprError(); 1446 1447 if (!AllPlaceArgs.empty()) 1448 PlacementArgs = AllPlaceArgs; 1449 1450 // FIXME: This is wrong: PlacementArgs misses out the first (size) argument. 1451 DiagnoseSentinelCalls(OperatorNew, PlacementLParen, PlacementArgs); 1452 1453 // FIXME: Missing call to CheckFunctionCall or equivalent 1454 } 1455 1456 // Warn if the type is over-aligned and is being allocated by global operator 1457 // new. 1458 if (PlacementArgs.empty() && OperatorNew && 1459 (OperatorNew->isImplicit() || 1460 getSourceManager().isInSystemHeader(OperatorNew->getLocStart()))) { 1461 if (unsigned Align = Context.getPreferredTypeAlign(AllocType.getTypePtr())){ 1462 unsigned SuitableAlign = Context.getTargetInfo().getSuitableAlign(); 1463 if (Align > SuitableAlign) 1464 Diag(StartLoc, diag::warn_overaligned_type) 1465 << AllocType 1466 << unsigned(Align / Context.getCharWidth()) 1467 << unsigned(SuitableAlign / Context.getCharWidth()); 1468 } 1469 } 1470 1471 QualType InitType = AllocType; 1472 // Array 'new' can't have any initializers except empty parentheses. 1473 // Initializer lists are also allowed, in C++11. Rely on the parser for the 1474 // dialect distinction. 1475 if (ResultType->isArrayType() || ArraySize) { 1476 if (!isLegalArrayNewInitializer(initStyle, Initializer)) { 1477 SourceRange InitRange(Inits[0]->getLocStart(), 1478 Inits[NumInits - 1]->getLocEnd()); 1479 Diag(StartLoc, diag::err_new_array_init_args) << InitRange; 1480 return ExprError(); 1481 } 1482 if (InitListExpr *ILE = dyn_cast_or_null<InitListExpr>(Initializer)) { 1483 // We do the initialization typechecking against the array type 1484 // corresponding to the number of initializers + 1 (to also check 1485 // default-initialization). 1486 unsigned NumElements = ILE->getNumInits() + 1; 1487 InitType = Context.getConstantArrayType(AllocType, 1488 llvm::APInt(Context.getTypeSize(Context.getSizeType()), NumElements), 1489 ArrayType::Normal, 0); 1490 } 1491 } 1492 1493 // If we can perform the initialization, and we've not already done so, 1494 // do it now. 1495 if (!AllocType->isDependentType() && 1496 !Expr::hasAnyTypeDependentArguments( 1497 llvm::makeArrayRef(Inits, NumInits))) { 1498 // C++11 [expr.new]p15: 1499 // A new-expression that creates an object of type T initializes that 1500 // object as follows: 1501 InitializationKind Kind 1502 // - If the new-initializer is omitted, the object is default- 1503 // initialized (8.5); if no initialization is performed, 1504 // the object has indeterminate value 1505 = initStyle == CXXNewExpr::NoInit 1506 ? InitializationKind::CreateDefault(TypeRange.getBegin()) 1507 // - Otherwise, the new-initializer is interpreted according to the 1508 // initialization rules of 8.5 for direct-initialization. 1509 : initStyle == CXXNewExpr::ListInit 1510 ? InitializationKind::CreateDirectList(TypeRange.getBegin()) 1511 : InitializationKind::CreateDirect(TypeRange.getBegin(), 1512 DirectInitRange.getBegin(), 1513 DirectInitRange.getEnd()); 1514 1515 InitializedEntity Entity 1516 = InitializedEntity::InitializeNew(StartLoc, InitType); 1517 InitializationSequence InitSeq(*this, Entity, Kind, MultiExprArg(Inits, NumInits)); 1518 ExprResult FullInit = InitSeq.Perform(*this, Entity, Kind, 1519 MultiExprArg(Inits, NumInits)); 1520 if (FullInit.isInvalid()) 1521 return ExprError(); 1522 1523 // FullInit is our initializer; strip off CXXBindTemporaryExprs, because 1524 // we don't want the initialized object to be destructed. 1525 if (CXXBindTemporaryExpr *Binder = 1526 dyn_cast_or_null<CXXBindTemporaryExpr>(FullInit.get())) 1527 FullInit = Binder->getSubExpr(); 1528 1529 Initializer = FullInit.get(); 1530 } 1531 1532 // Mark the new and delete operators as referenced. 1533 if (OperatorNew) { 1534 if (DiagnoseUseOfDecl(OperatorNew, StartLoc)) 1535 return ExprError(); 1536 MarkFunctionReferenced(StartLoc, OperatorNew); 1537 } 1538 if (OperatorDelete) { 1539 if (DiagnoseUseOfDecl(OperatorDelete, StartLoc)) 1540 return ExprError(); 1541 MarkFunctionReferenced(StartLoc, OperatorDelete); 1542 } 1543 1544 // C++0x [expr.new]p17: 1545 // If the new expression creates an array of objects of class type, 1546 // access and ambiguity control are done for the destructor. 1547 QualType BaseAllocType = Context.getBaseElementType(AllocType); 1548 if (ArraySize && !BaseAllocType->isDependentType()) { 1549 if (const RecordType *BaseRecordType = BaseAllocType->getAs<RecordType>()) { 1550 if (CXXDestructorDecl *dtor = LookupDestructor( 1551 cast<CXXRecordDecl>(BaseRecordType->getDecl()))) { 1552 MarkFunctionReferenced(StartLoc, dtor); 1553 CheckDestructorAccess(StartLoc, dtor, 1554 PDiag(diag::err_access_dtor) 1555 << BaseAllocType); 1556 if (DiagnoseUseOfDecl(dtor, StartLoc)) 1557 return ExprError(); 1558 } 1559 } 1560 } 1561 1562 return new (Context) 1563 CXXNewExpr(Context, UseGlobal, OperatorNew, OperatorDelete, 1564 UsualArrayDeleteWantsSize, PlacementArgs, TypeIdParens, 1565 ArraySize, initStyle, Initializer, ResultType, AllocTypeInfo, 1566 Range, DirectInitRange); 1567} 1568 1569/// \brief Checks that a type is suitable as the allocated type 1570/// in a new-expression. 1571bool Sema::CheckAllocatedType(QualType AllocType, SourceLocation Loc, 1572 SourceRange R) { 1573 // C++ 5.3.4p1: "[The] type shall be a complete object type, but not an 1574 // abstract class type or array thereof. 1575 if (AllocType->isFunctionType()) 1576 return Diag(Loc, diag::err_bad_new_type) 1577 << AllocType << 0 << R; 1578 else if (AllocType->isReferenceType()) 1579 return Diag(Loc, diag::err_bad_new_type) 1580 << AllocType << 1 << R; 1581 else if (!AllocType->isDependentType() && 1582 RequireCompleteType(Loc, AllocType, diag::err_new_incomplete_type,R)) 1583 return true; 1584 else if (RequireNonAbstractType(Loc, AllocType, 1585 diag::err_allocation_of_abstract_type)) 1586 return true; 1587 else if (AllocType->isVariablyModifiedType()) 1588 return Diag(Loc, diag::err_variably_modified_new_type) 1589 << AllocType; 1590 else if (unsigned AddressSpace = AllocType.getAddressSpace()) 1591 return Diag(Loc, diag::err_address_space_qualified_new) 1592 << AllocType.getUnqualifiedType() << AddressSpace; 1593 else if (getLangOpts().ObjCAutoRefCount) { 1594 if (const ArrayType *AT = Context.getAsArrayType(AllocType)) { 1595 QualType BaseAllocType = Context.getBaseElementType(AT); 1596 if (BaseAllocType.getObjCLifetime() == Qualifiers::OCL_None && 1597 BaseAllocType->isObjCLifetimeType()) 1598 return Diag(Loc, diag::err_arc_new_array_without_ownership) 1599 << BaseAllocType; 1600 } 1601 } 1602 1603 return false; 1604} 1605 1606/// \brief Determine whether the given function is a non-placement 1607/// deallocation function. 1608static bool isNonPlacementDeallocationFunction(Sema &S, FunctionDecl *FD) { 1609 if (FD->isInvalidDecl()) 1610 return false; 1611 1612 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD)) 1613 return Method->isUsualDeallocationFunction(); 1614 1615 if (FD->getOverloadedOperator() != OO_Delete && 1616 FD->getOverloadedOperator() != OO_Array_Delete) 1617 return false; 1618 1619 if (FD->getNumParams() == 1) 1620 return true; 1621 1622 return S.getLangOpts().SizedDeallocation && FD->getNumParams() == 2 && 1623 S.Context.hasSameUnqualifiedType(FD->getParamDecl(1)->getType(), 1624 S.Context.getSizeType()); 1625} 1626 1627/// FindAllocationFunctions - Finds the overloads of operator new and delete 1628/// that are appropriate for the allocation. 1629bool Sema::FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range, 1630 bool UseGlobal, QualType AllocType, 1631 bool IsArray, MultiExprArg PlaceArgs, 1632 FunctionDecl *&OperatorNew, 1633 FunctionDecl *&OperatorDelete) { 1634 // --- Choosing an allocation function --- 1635 // C++ 5.3.4p8 - 14 & 18 1636 // 1) If UseGlobal is true, only look in the global scope. Else, also look 1637 // in the scope of the allocated class. 1638 // 2) If an array size is given, look for operator new[], else look for 1639 // operator new. 1640 // 3) The first argument is always size_t. Append the arguments from the 1641 // placement form. 1642 1643 SmallVector<Expr*, 8> AllocArgs(1 + PlaceArgs.size()); 1644 // We don't care about the actual value of this argument. 1645 // FIXME: Should the Sema create the expression and embed it in the syntax 1646 // tree? Or should the consumer just recalculate the value? 1647 IntegerLiteral Size(Context, llvm::APInt::getNullValue( 1648 Context.getTargetInfo().getPointerWidth(0)), 1649 Context.getSizeType(), 1650 SourceLocation()); 1651 AllocArgs[0] = &Size; 1652 std::copy(PlaceArgs.begin(), PlaceArgs.end(), AllocArgs.begin() + 1); 1653 1654 // C++ [expr.new]p8: 1655 // If the allocated type is a non-array type, the allocation 1656 // function's name is operator new and the deallocation function's 1657 // name is operator delete. If the allocated type is an array 1658 // type, the allocation function's name is operator new[] and the 1659 // deallocation function's name is operator delete[]. 1660 DeclarationName NewName = Context.DeclarationNames.getCXXOperatorName( 1661 IsArray ? OO_Array_New : OO_New); 1662 DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName( 1663 IsArray ? OO_Array_Delete : OO_Delete); 1664 1665 QualType AllocElemType = Context.getBaseElementType(AllocType); 1666 1667 if (AllocElemType->isRecordType() && !UseGlobal) { 1668 CXXRecordDecl *Record 1669 = cast<CXXRecordDecl>(AllocElemType->getAs<RecordType>()->getDecl()); 1670 if (FindAllocationOverload(StartLoc, Range, NewName, AllocArgs, Record, 1671 /*AllowMissing=*/true, OperatorNew)) 1672 return true; 1673 } 1674 1675 if (!OperatorNew) { 1676 // Didn't find a member overload. Look for a global one. 1677 DeclareGlobalNewDelete(); 1678 DeclContext *TUDecl = Context.getTranslationUnitDecl(); 1679 bool FallbackEnabled = IsArray && Context.getLangOpts().MSVCCompat; 1680 if (FindAllocationOverload(StartLoc, Range, NewName, AllocArgs, TUDecl, 1681 /*AllowMissing=*/FallbackEnabled, OperatorNew, 1682 /*Diagnose=*/!FallbackEnabled)) { 1683 if (!FallbackEnabled) 1684 return true; 1685 1686 // MSVC will fall back on trying to find a matching global operator new 1687 // if operator new[] cannot be found. Also, MSVC will leak by not 1688 // generating a call to operator delete or operator delete[], but we 1689 // will not replicate that bug. 1690 NewName = Context.DeclarationNames.getCXXOperatorName(OO_New); 1691 DeleteName = Context.DeclarationNames.getCXXOperatorName(OO_Delete); 1692 if (FindAllocationOverload(StartLoc, Range, NewName, AllocArgs, TUDecl, 1693 /*AllowMissing=*/false, OperatorNew)) 1694 return true; 1695 } 1696 } 1697 1698 // We don't need an operator delete if we're running under 1699 // -fno-exceptions. 1700 if (!getLangOpts().Exceptions) { 1701 OperatorDelete = nullptr; 1702 return false; 1703 } 1704 1705 // C++ [expr.new]p19: 1706 // 1707 // If the new-expression begins with a unary :: operator, the 1708 // deallocation function's name is looked up in the global 1709 // scope. Otherwise, if the allocated type is a class type T or an 1710 // array thereof, the deallocation function's name is looked up in 1711 // the scope of T. If this lookup fails to find the name, or if 1712 // the allocated type is not a class type or array thereof, the 1713 // deallocation function's name is looked up in the global scope. 1714 LookupResult FoundDelete(*this, DeleteName, StartLoc, LookupOrdinaryName); 1715 if (AllocElemType->isRecordType() && !UseGlobal) { 1716 CXXRecordDecl *RD 1717 = cast<CXXRecordDecl>(AllocElemType->getAs<RecordType>()->getDecl()); 1718 LookupQualifiedName(FoundDelete, RD); 1719 } 1720 if (FoundDelete.isAmbiguous()) 1721 return true; // FIXME: clean up expressions? 1722 1723 if (FoundDelete.empty()) { 1724 DeclareGlobalNewDelete(); 1725 LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl()); 1726 } 1727 1728 FoundDelete.suppressDiagnostics(); 1729 1730 SmallVector<std::pair<DeclAccessPair,FunctionDecl*>, 2> Matches; 1731 1732 // Whether we're looking for a placement operator delete is dictated 1733 // by whether we selected a placement operator new, not by whether 1734 // we had explicit placement arguments. This matters for things like 1735 // struct A { void *operator new(size_t, int = 0); ... }; 1736 // A *a = new A() 1737 bool isPlacementNew = (!PlaceArgs.empty() || OperatorNew->param_size() != 1); 1738 1739 if (isPlacementNew) { 1740 // C++ [expr.new]p20: 1741 // A declaration of a placement deallocation function matches the 1742 // declaration of a placement allocation function if it has the 1743 // same number of parameters and, after parameter transformations 1744 // (8.3.5), all parameter types except the first are 1745 // identical. [...] 1746 // 1747 // To perform this comparison, we compute the function type that 1748 // the deallocation function should have, and use that type both 1749 // for template argument deduction and for comparison purposes. 1750 // 1751 // FIXME: this comparison should ignore CC and the like. 1752 QualType ExpectedFunctionType; 1753 { 1754 const FunctionProtoType *Proto 1755 = OperatorNew->getType()->getAs<FunctionProtoType>(); 1756 1757 SmallVector<QualType, 4> ArgTypes; 1758 ArgTypes.push_back(Context.VoidPtrTy); 1759 for (unsigned I = 1, N = Proto->getNumParams(); I < N; ++I) 1760 ArgTypes.push_back(Proto->getParamType(I)); 1761 1762 FunctionProtoType::ExtProtoInfo EPI; 1763 EPI.Variadic = Proto->isVariadic(); 1764 1765 ExpectedFunctionType 1766 = Context.getFunctionType(Context.VoidTy, ArgTypes, EPI); 1767 } 1768 1769 for (LookupResult::iterator D = FoundDelete.begin(), 1770 DEnd = FoundDelete.end(); 1771 D != DEnd; ++D) { 1772 FunctionDecl *Fn = nullptr; 1773 if (FunctionTemplateDecl *FnTmpl 1774 = dyn_cast<FunctionTemplateDecl>((*D)->getUnderlyingDecl())) { 1775 // Perform template argument deduction to try to match the 1776 // expected function type. 1777 TemplateDeductionInfo Info(StartLoc); 1778 if (DeduceTemplateArguments(FnTmpl, nullptr, ExpectedFunctionType, Fn, 1779 Info)) 1780 continue; 1781 } else 1782 Fn = cast<FunctionDecl>((*D)->getUnderlyingDecl()); 1783 1784 if (Context.hasSameType(Fn->getType(), ExpectedFunctionType)) 1785 Matches.push_back(std::make_pair(D.getPair(), Fn)); 1786 } 1787 } else { 1788 // C++ [expr.new]p20: 1789 // [...] Any non-placement deallocation function matches a 1790 // non-placement allocation function. [...] 1791 for (LookupResult::iterator D = FoundDelete.begin(), 1792 DEnd = FoundDelete.end(); 1793 D != DEnd; ++D) { 1794 if (FunctionDecl *Fn = dyn_cast<FunctionDecl>((*D)->getUnderlyingDecl())) 1795 if (isNonPlacementDeallocationFunction(*this, Fn)) 1796 Matches.push_back(std::make_pair(D.getPair(), Fn)); 1797 } 1798 1799 // C++1y [expr.new]p22: 1800 // For a non-placement allocation function, the normal deallocation 1801 // function lookup is used 1802 // C++1y [expr.delete]p?: 1803 // If [...] deallocation function lookup finds both a usual deallocation 1804 // function with only a pointer parameter and a usual deallocation 1805 // function with both a pointer parameter and a size parameter, then the 1806 // selected deallocation function shall be the one with two parameters. 1807 // Otherwise, the selected deallocation function shall be the function 1808 // with one parameter. 1809 if (getLangOpts().SizedDeallocation && Matches.size() == 2) { 1810 if (Matches[0].second->getNumParams() == 1) 1811 Matches.erase(Matches.begin()); 1812 else 1813 Matches.erase(Matches.begin() + 1); 1814 assert(Matches[0].second->getNumParams() == 2 && 1815 "found an unexpected usual deallocation function"); 1816 } 1817 } 1818 1819 // C++ [expr.new]p20: 1820 // [...] If the lookup finds a single matching deallocation 1821 // function, that function will be called; otherwise, no 1822 // deallocation function will be called. 1823 if (Matches.size() == 1) { 1824 OperatorDelete = Matches[0].second; 1825 1826 // C++0x [expr.new]p20: 1827 // If the lookup finds the two-parameter form of a usual 1828 // deallocation function (3.7.4.2) and that function, considered 1829 // as a placement deallocation function, would have been 1830 // selected as a match for the allocation function, the program 1831 // is ill-formed. 1832 if (!PlaceArgs.empty() && getLangOpts().CPlusPlus11 && 1833 isNonPlacementDeallocationFunction(*this, OperatorDelete)) { 1834 Diag(StartLoc, diag::err_placement_new_non_placement_delete) 1835 << SourceRange(PlaceArgs.front()->getLocStart(), 1836 PlaceArgs.back()->getLocEnd()); 1837 if (!OperatorDelete->isImplicit()) 1838 Diag(OperatorDelete->getLocation(), diag::note_previous_decl) 1839 << DeleteName; 1840 } else { 1841 CheckAllocationAccess(StartLoc, Range, FoundDelete.getNamingClass(), 1842 Matches[0].first); 1843 } 1844 } 1845 1846 return false; 1847} 1848 1849/// \brief Find an fitting overload for the allocation function 1850/// in the specified scope. 1851/// 1852/// \param StartLoc The location of the 'new' token. 1853/// \param Range The range of the placement arguments. 1854/// \param Name The name of the function ('operator new' or 'operator new[]'). 1855/// \param Args The placement arguments specified. 1856/// \param Ctx The scope in which we should search; either a class scope or the 1857/// translation unit. 1858/// \param AllowMissing If \c true, report an error if we can't find any 1859/// allocation functions. Otherwise, succeed but don't fill in \p 1860/// Operator. 1861/// \param Operator Filled in with the found allocation function. Unchanged if 1862/// no allocation function was found. 1863/// \param Diagnose If \c true, issue errors if the allocation function is not 1864/// usable. 1865bool Sema::FindAllocationOverload(SourceLocation StartLoc, SourceRange Range, 1866 DeclarationName Name, MultiExprArg Args, 1867 DeclContext *Ctx, 1868 bool AllowMissing, FunctionDecl *&Operator, 1869 bool Diagnose) { 1870 LookupResult R(*this, Name, StartLoc, LookupOrdinaryName); 1871 LookupQualifiedName(R, Ctx); 1872 if (R.empty()) { 1873 if (AllowMissing || !Diagnose) 1874 return false; 1875 return Diag(StartLoc, diag::err_ovl_no_viable_function_in_call) 1876 << Name << Range; 1877 } 1878 1879 if (R.isAmbiguous()) 1880 return true; 1881 1882 R.suppressDiagnostics(); 1883 1884 OverloadCandidateSet Candidates(StartLoc, OverloadCandidateSet::CSK_Normal); 1885 for (LookupResult::iterator Alloc = R.begin(), AllocEnd = R.end(); 1886 Alloc != AllocEnd; ++Alloc) { 1887 // Even member operator new/delete are implicitly treated as 1888 // static, so don't use AddMemberCandidate. 1889 NamedDecl *D = (*Alloc)->getUnderlyingDecl(); 1890 1891 if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) { 1892 AddTemplateOverloadCandidate(FnTemplate, Alloc.getPair(), 1893 /*ExplicitTemplateArgs=*/nullptr, 1894 Args, Candidates, 1895 /*SuppressUserConversions=*/false); 1896 continue; 1897 } 1898 1899 FunctionDecl *Fn = cast<FunctionDecl>(D); 1900 AddOverloadCandidate(Fn, Alloc.getPair(), Args, Candidates, 1901 /*SuppressUserConversions=*/false); 1902 } 1903 1904 // Do the resolution. 1905 OverloadCandidateSet::iterator Best; 1906 switch (Candidates.BestViableFunction(*this, StartLoc, Best)) { 1907 case OR_Success: { 1908 // Got one! 1909 FunctionDecl *FnDecl = Best->Function; 1910 if (CheckAllocationAccess(StartLoc, Range, R.getNamingClass(), 1911 Best->FoundDecl, Diagnose) == AR_inaccessible) 1912 return true; 1913 1914 Operator = FnDecl; 1915 return false; 1916 } 1917 1918 case OR_No_Viable_Function: 1919 if (Diagnose) { 1920 Diag(StartLoc, diag::err_ovl_no_viable_function_in_call) 1921 << Name << Range; 1922 Candidates.NoteCandidates(*this, OCD_AllCandidates, Args); 1923 } 1924 return true; 1925 1926 case OR_Ambiguous: 1927 if (Diagnose) { 1928 Diag(StartLoc, diag::err_ovl_ambiguous_call) 1929 << Name << Range; 1930 Candidates.NoteCandidates(*this, OCD_ViableCandidates, Args); 1931 } 1932 return true; 1933 1934 case OR_Deleted: { 1935 if (Diagnose) { 1936 Diag(StartLoc, diag::err_ovl_deleted_call) 1937 << Best->Function->isDeleted() 1938 << Name 1939 << getDeletedOrUnavailableSuffix(Best->Function) 1940 << Range; 1941 Candidates.NoteCandidates(*this, OCD_AllCandidates, Args); 1942 } 1943 return true; 1944 } 1945 } 1946 llvm_unreachable("Unreachable, bad result from BestViableFunction"); 1947} 1948 1949 1950/// DeclareGlobalNewDelete - Declare the global forms of operator new and 1951/// delete. These are: 1952/// @code 1953/// // C++03: 1954/// void* operator new(std::size_t) throw(std::bad_alloc); 1955/// void* operator new[](std::size_t) throw(std::bad_alloc); 1956/// void operator delete(void *) throw(); 1957/// void operator delete[](void *) throw(); 1958/// // C++11: 1959/// void* operator new(std::size_t); 1960/// void* operator new[](std::size_t); 1961/// void operator delete(void *) noexcept; 1962/// void operator delete[](void *) noexcept; 1963/// // C++1y: 1964/// void* operator new(std::size_t); 1965/// void* operator new[](std::size_t); 1966/// void operator delete(void *) noexcept; 1967/// void operator delete[](void *) noexcept; 1968/// void operator delete(void *, std::size_t) noexcept; 1969/// void operator delete[](void *, std::size_t) noexcept; 1970/// @endcode 1971/// Note that the placement and nothrow forms of new are *not* implicitly 1972/// declared. Their use requires including \<new\>. 1973void Sema::DeclareGlobalNewDelete() { 1974 if (GlobalNewDeleteDeclared) 1975 return; 1976 1977 // C++ [basic.std.dynamic]p2: 1978 // [...] The following allocation and deallocation functions (18.4) are 1979 // implicitly declared in global scope in each translation unit of a 1980 // program 1981 // 1982 // C++03: 1983 // void* operator new(std::size_t) throw(std::bad_alloc); 1984 // void* operator new[](std::size_t) throw(std::bad_alloc); 1985 // void operator delete(void*) throw(); 1986 // void operator delete[](void*) throw(); 1987 // C++11: 1988 // void* operator new(std::size_t); 1989 // void* operator new[](std::size_t); 1990 // void operator delete(void*) noexcept; 1991 // void operator delete[](void*) noexcept; 1992 // C++1y: 1993 // void* operator new(std::size_t); 1994 // void* operator new[](std::size_t); 1995 // void operator delete(void*) noexcept; 1996 // void operator delete[](void*) noexcept; 1997 // void operator delete(void*, std::size_t) noexcept; 1998 // void operator delete[](void*, std::size_t) noexcept; 1999 // 2000 // These implicit declarations introduce only the function names operator 2001 // new, operator new[], operator delete, operator delete[]. 2002 // 2003 // Here, we need to refer to std::bad_alloc, so we will implicitly declare 2004 // "std" or "bad_alloc" as necessary to form the exception specification. 2005 // However, we do not make these implicit declarations visible to name 2006 // lookup. 2007 if (!StdBadAlloc && !getLangOpts().CPlusPlus11) { 2008 // The "std::bad_alloc" class has not yet been declared, so build it 2009 // implicitly. 2010 StdBadAlloc = CXXRecordDecl::Create(Context, TTK_Class, 2011 getOrCreateStdNamespace(), 2012 SourceLocation(), SourceLocation(), 2013 &PP.getIdentifierTable().get("bad_alloc"), 2014 nullptr); 2015 getStdBadAlloc()->setImplicit(true); 2016 } 2017 2018 GlobalNewDeleteDeclared = true; 2019 2020 QualType VoidPtr = Context.getPointerType(Context.VoidTy); 2021 QualType SizeT = Context.getSizeType(); 2022 bool AssumeSaneOperatorNew = getLangOpts().AssumeSaneOperatorNew; 2023 2024 DeclareGlobalAllocationFunction( 2025 Context.DeclarationNames.getCXXOperatorName(OO_New), 2026 VoidPtr, SizeT, QualType(), AssumeSaneOperatorNew); 2027 DeclareGlobalAllocationFunction( 2028 Context.DeclarationNames.getCXXOperatorName(OO_Array_New), 2029 VoidPtr, SizeT, QualType(), AssumeSaneOperatorNew); 2030 DeclareGlobalAllocationFunction( 2031 Context.DeclarationNames.getCXXOperatorName(OO_Delete), 2032 Context.VoidTy, VoidPtr); 2033 DeclareGlobalAllocationFunction( 2034 Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete), 2035 Context.VoidTy, VoidPtr); 2036 if (getLangOpts().SizedDeallocation) { 2037 DeclareGlobalAllocationFunction( 2038 Context.DeclarationNames.getCXXOperatorName(OO_Delete), 2039 Context.VoidTy, VoidPtr, Context.getSizeType()); 2040 DeclareGlobalAllocationFunction( 2041 Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete), 2042 Context.VoidTy, VoidPtr, Context.getSizeType()); 2043 } 2044} 2045 2046/// DeclareGlobalAllocationFunction - Declares a single implicit global 2047/// allocation function if it doesn't already exist. 2048void Sema::DeclareGlobalAllocationFunction(DeclarationName Name, 2049 QualType Return, 2050 QualType Param1, QualType Param2, 2051 bool AddMallocAttr) { 2052 DeclContext *GlobalCtx = Context.getTranslationUnitDecl(); 2053 unsigned NumParams = Param2.isNull() ? 1 : 2; 2054 2055 // Check if this function is already declared. 2056 DeclContext::lookup_result R = GlobalCtx->lookup(Name); 2057 for (DeclContext::lookup_iterator Alloc = R.begin(), AllocEnd = R.end(); 2058 Alloc != AllocEnd; ++Alloc) { 2059 // Only look at non-template functions, as it is the predefined, 2060 // non-templated allocation function we are trying to declare here. 2061 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(*Alloc)) { 2062 if (Func->getNumParams() == NumParams) { 2063 QualType InitialParam1Type = 2064 Context.getCanonicalType(Func->getParamDecl(0) 2065 ->getType().getUnqualifiedType()); 2066 QualType InitialParam2Type = 2067 NumParams == 2 2068 ? Context.getCanonicalType(Func->getParamDecl(1) 2069 ->getType().getUnqualifiedType()) 2070 : QualType(); 2071 // FIXME: Do we need to check for default arguments here? 2072 if (InitialParam1Type == Param1 && 2073 (NumParams == 1 || InitialParam2Type == Param2)) { 2074 if (AddMallocAttr && !Func->hasAttr<MallocAttr>()) 2075 Func->addAttr(MallocAttr::CreateImplicit(Context)); 2076 // Make the function visible to name lookup, even if we found it in 2077 // an unimported module. It either is an implicitly-declared global 2078 // allocation function, or is suppressing that function. 2079 Func->setHidden(false); 2080 return; 2081 } 2082 } 2083 } 2084 } 2085 2086 FunctionProtoType::ExtProtoInfo EPI; 2087 2088 QualType BadAllocType; 2089 bool HasBadAllocExceptionSpec 2090 = (Name.getCXXOverloadedOperator() == OO_New || 2091 Name.getCXXOverloadedOperator() == OO_Array_New); 2092 if (HasBadAllocExceptionSpec) { 2093 if (!getLangOpts().CPlusPlus11) { 2094 BadAllocType = Context.getTypeDeclType(getStdBadAlloc()); 2095 assert(StdBadAlloc && "Must have std::bad_alloc declared"); 2096 EPI.ExceptionSpec.Type = EST_Dynamic; 2097 EPI.ExceptionSpec.Exceptions = llvm::makeArrayRef(BadAllocType); 2098 } 2099 } else { 2100 EPI.ExceptionSpec = 2101 getLangOpts().CPlusPlus11 ? EST_BasicNoexcept : EST_DynamicNone; 2102 } 2103 2104 QualType Params[] = { Param1, Param2 }; 2105 2106 QualType FnType = Context.getFunctionType( 2107 Return, llvm::makeArrayRef(Params, NumParams), EPI); 2108 FunctionDecl *Alloc = 2109 FunctionDecl::Create(Context, GlobalCtx, SourceLocation(), 2110 SourceLocation(), Name, 2111 FnType, /*TInfo=*/nullptr, SC_None, false, true); 2112 Alloc->setImplicit(); 2113 2114 if (AddMallocAttr) 2115 Alloc->addAttr(MallocAttr::CreateImplicit(Context)); 2116 2117 ParmVarDecl *ParamDecls[2]; 2118 for (unsigned I = 0; I != NumParams; ++I) { 2119 ParamDecls[I] = ParmVarDecl::Create(Context, Alloc, SourceLocation(), 2120 SourceLocation(), nullptr, 2121 Params[I], /*TInfo=*/nullptr, 2122 SC_None, nullptr); 2123 ParamDecls[I]->setImplicit(); 2124 } 2125 Alloc->setParams(llvm::makeArrayRef(ParamDecls, NumParams)); 2126 2127 Context.getTranslationUnitDecl()->addDecl(Alloc); 2128 IdResolver.tryAddTopLevelDecl(Alloc, Name); 2129} 2130 2131FunctionDecl *Sema::FindUsualDeallocationFunction(SourceLocation StartLoc, 2132 bool CanProvideSize, 2133 DeclarationName Name) { 2134 DeclareGlobalNewDelete(); 2135 2136 LookupResult FoundDelete(*this, Name, StartLoc, LookupOrdinaryName); 2137 LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl()); 2138 2139 // C++ [expr.new]p20: 2140 // [...] Any non-placement deallocation function matches a 2141 // non-placement allocation function. [...] 2142 llvm::SmallVector<FunctionDecl*, 2> Matches; 2143 for (LookupResult::iterator D = FoundDelete.begin(), 2144 DEnd = FoundDelete.end(); 2145 D != DEnd; ++D) { 2146 if (FunctionDecl *Fn = dyn_cast<FunctionDecl>(*D)) 2147 if (isNonPlacementDeallocationFunction(*this, Fn)) 2148 Matches.push_back(Fn); 2149 } 2150 2151 // C++1y [expr.delete]p?: 2152 // If the type is complete and deallocation function lookup finds both a 2153 // usual deallocation function with only a pointer parameter and a usual 2154 // deallocation function with both a pointer parameter and a size 2155 // parameter, then the selected deallocation function shall be the one 2156 // with two parameters. Otherwise, the selected deallocation function 2157 // shall be the function with one parameter. 2158 if (getLangOpts().SizedDeallocation && Matches.size() == 2) { 2159 unsigned NumArgs = CanProvideSize ? 2 : 1; 2160 if (Matches[0]->getNumParams() != NumArgs) 2161 Matches.erase(Matches.begin()); 2162 else 2163 Matches.erase(Matches.begin() + 1); 2164 assert(Matches[0]->getNumParams() == NumArgs && 2165 "found an unexpected usual deallocation function"); 2166 } 2167 2168 assert(Matches.size() == 1 && 2169 "unexpectedly have multiple usual deallocation functions"); 2170 return Matches.front(); 2171} 2172 2173bool Sema::FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD, 2174 DeclarationName Name, 2175 FunctionDecl* &Operator, bool Diagnose) { 2176 LookupResult Found(*this, Name, StartLoc, LookupOrdinaryName); 2177 // Try to find operator delete/operator delete[] in class scope. 2178 LookupQualifiedName(Found, RD); 2179 2180 if (Found.isAmbiguous()) 2181 return true; 2182 2183 Found.suppressDiagnostics(); 2184 2185 SmallVector<DeclAccessPair,4> Matches; 2186 for (LookupResult::iterator F = Found.begin(), FEnd = Found.end(); 2187 F != FEnd; ++F) { 2188 NamedDecl *ND = (*F)->getUnderlyingDecl(); 2189 2190 // Ignore template operator delete members from the check for a usual 2191 // deallocation function. 2192 if (isa<FunctionTemplateDecl>(ND)) 2193 continue; 2194 2195 if (cast<CXXMethodDecl>(ND)->isUsualDeallocationFunction()) 2196 Matches.push_back(F.getPair()); 2197 } 2198 2199 // There's exactly one suitable operator; pick it. 2200 if (Matches.size() == 1) { 2201 Operator = cast<CXXMethodDecl>(Matches[0]->getUnderlyingDecl()); 2202 2203 if (Operator->isDeleted()) { 2204 if (Diagnose) { 2205 Diag(StartLoc, diag::err_deleted_function_use); 2206 NoteDeletedFunction(Operator); 2207 } 2208 return true; 2209 } 2210 2211 if (CheckAllocationAccess(StartLoc, SourceRange(), Found.getNamingClass(), 2212 Matches[0], Diagnose) == AR_inaccessible) 2213 return true; 2214 2215 return false; 2216 2217 // We found multiple suitable operators; complain about the ambiguity. 2218 } else if (!Matches.empty()) { 2219 if (Diagnose) { 2220 Diag(StartLoc, diag::err_ambiguous_suitable_delete_member_function_found) 2221 << Name << RD; 2222 2223 for (SmallVectorImpl<DeclAccessPair>::iterator 2224 F = Matches.begin(), FEnd = Matches.end(); F != FEnd; ++F) 2225 Diag((*F)->getUnderlyingDecl()->getLocation(), 2226 diag::note_member_declared_here) << Name; 2227 } 2228 return true; 2229 } 2230 2231 // We did find operator delete/operator delete[] declarations, but 2232 // none of them were suitable. 2233 if (!Found.empty()) { 2234 if (Diagnose) { 2235 Diag(StartLoc, diag::err_no_suitable_delete_member_function_found) 2236 << Name << RD; 2237 2238 for (LookupResult::iterator F = Found.begin(), FEnd = Found.end(); 2239 F != FEnd; ++F) 2240 Diag((*F)->getUnderlyingDecl()->getLocation(), 2241 diag::note_member_declared_here) << Name; 2242 } 2243 return true; 2244 } 2245 2246 Operator = nullptr; 2247 return false; 2248} 2249 2250/// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in: 2251/// @code ::delete ptr; @endcode 2252/// or 2253/// @code delete [] ptr; @endcode 2254ExprResult 2255Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal, 2256 bool ArrayForm, Expr *ExE) { 2257 // C++ [expr.delete]p1: 2258 // The operand shall have a pointer type, or a class type having a single 2259 // non-explicit conversion function to a pointer type. The result has type 2260 // void. 2261 // 2262 // DR599 amends "pointer type" to "pointer to object type" in both cases. 2263 2264 ExprResult Ex = ExE; 2265 FunctionDecl *OperatorDelete = nullptr; 2266 bool ArrayFormAsWritten = ArrayForm; 2267 bool UsualArrayDeleteWantsSize = false; 2268 2269 if (!Ex.get()->isTypeDependent()) { 2270 // Perform lvalue-to-rvalue cast, if needed. 2271 Ex = DefaultLvalueConversion(Ex.get()); 2272 if (Ex.isInvalid()) 2273 return ExprError(); 2274 2275 QualType Type = Ex.get()->getType(); 2276 2277 class DeleteConverter : public ContextualImplicitConverter { 2278 public: 2279 DeleteConverter() : ContextualImplicitConverter(false, true) {} 2280 2281 bool match(QualType ConvType) override { 2282 // FIXME: If we have an operator T* and an operator void*, we must pick 2283 // the operator T*. 2284 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 2285 if (ConvPtrType->getPointeeType()->isIncompleteOrObjectType()) 2286 return true; 2287 return false; 2288 } 2289 2290 SemaDiagnosticBuilder diagnoseNoMatch(Sema &S, SourceLocation Loc, 2291 QualType T) override { 2292 return S.Diag(Loc, diag::err_delete_operand) << T; 2293 } 2294 2295 SemaDiagnosticBuilder diagnoseIncomplete(Sema &S, SourceLocation Loc, 2296 QualType T) override { 2297 return S.Diag(Loc, diag::err_delete_incomplete_class_type) << T; 2298 } 2299 2300 SemaDiagnosticBuilder diagnoseExplicitConv(Sema &S, SourceLocation Loc, 2301 QualType T, 2302 QualType ConvTy) override { 2303 return S.Diag(Loc, diag::err_delete_explicit_conversion) << T << ConvTy; 2304 } 2305 2306 SemaDiagnosticBuilder noteExplicitConv(Sema &S, CXXConversionDecl *Conv, 2307 QualType ConvTy) override { 2308 return S.Diag(Conv->getLocation(), diag::note_delete_conversion) 2309 << ConvTy; 2310 } 2311 2312 SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc, 2313 QualType T) override { 2314 return S.Diag(Loc, diag::err_ambiguous_delete_operand) << T; 2315 } 2316 2317 SemaDiagnosticBuilder noteAmbiguous(Sema &S, CXXConversionDecl *Conv, 2318 QualType ConvTy) override { 2319 return S.Diag(Conv->getLocation(), diag::note_delete_conversion) 2320 << ConvTy; 2321 } 2322 2323 SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc, 2324 QualType T, 2325 QualType ConvTy) override { 2326 llvm_unreachable("conversion functions are permitted"); 2327 } 2328 } Converter; 2329 2330 Ex = PerformContextualImplicitConversion(StartLoc, Ex.get(), Converter); 2331 if (Ex.isInvalid()) 2332 return ExprError(); 2333 Type = Ex.get()->getType(); 2334 if (!Converter.match(Type)) 2335 // FIXME: PerformContextualImplicitConversion should return ExprError 2336 // itself in this case. 2337 return ExprError(); 2338 2339 QualType Pointee = Type->getAs<PointerType>()->getPointeeType(); 2340 QualType PointeeElem = Context.getBaseElementType(Pointee); 2341 2342 if (unsigned AddressSpace = Pointee.getAddressSpace()) 2343 return Diag(Ex.get()->getLocStart(), 2344 diag::err_address_space_qualified_delete) 2345 << Pointee.getUnqualifiedType() << AddressSpace; 2346 2347 CXXRecordDecl *PointeeRD = nullptr; 2348 if (Pointee->isVoidType() && !isSFINAEContext()) { 2349 // The C++ standard bans deleting a pointer to a non-object type, which 2350 // effectively bans deletion of "void*". However, most compilers support 2351 // this, so we treat it as a warning unless we're in a SFINAE context. 2352 Diag(StartLoc, diag::ext_delete_void_ptr_operand) 2353 << Type << Ex.get()->getSourceRange(); 2354 } else if (Pointee->isFunctionType() || Pointee->isVoidType()) { 2355 return ExprError(Diag(StartLoc, diag::err_delete_operand) 2356 << Type << Ex.get()->getSourceRange()); 2357 } else if (!Pointee->isDependentType()) { 2358 if (!RequireCompleteType(StartLoc, Pointee, 2359 diag::warn_delete_incomplete, Ex.get())) { 2360 if (const RecordType *RT = PointeeElem->getAs<RecordType>()) 2361 PointeeRD = cast<CXXRecordDecl>(RT->getDecl()); 2362 } 2363 } 2364 2365 // C++ [expr.delete]p2: 2366 // [Note: a pointer to a const type can be the operand of a 2367 // delete-expression; it is not necessary to cast away the constness 2368 // (5.2.11) of the pointer expression before it is used as the operand 2369 // of the delete-expression. ] 2370 2371 if (Pointee->isArrayType() && !ArrayForm) { 2372 Diag(StartLoc, diag::warn_delete_array_type) 2373 << Type << Ex.get()->getSourceRange() 2374 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(StartLoc), "[]"); 2375 ArrayForm = true; 2376 } 2377 2378 DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName( 2379 ArrayForm ? OO_Array_Delete : OO_Delete); 2380 2381 if (PointeeRD) { 2382 if (!UseGlobal && 2383 FindDeallocationFunction(StartLoc, PointeeRD, DeleteName, 2384 OperatorDelete)) 2385 return ExprError(); 2386 2387 // If we're allocating an array of records, check whether the 2388 // usual operator delete[] has a size_t parameter. 2389 if (ArrayForm) { 2390 // If the user specifically asked to use the global allocator, 2391 // we'll need to do the lookup into the class. 2392 if (UseGlobal) 2393 UsualArrayDeleteWantsSize = 2394 doesUsualArrayDeleteWantSize(*this, StartLoc, PointeeElem); 2395 2396 // Otherwise, the usual operator delete[] should be the 2397 // function we just found. 2398 else if (OperatorDelete && isa<CXXMethodDecl>(OperatorDelete)) 2399 UsualArrayDeleteWantsSize = (OperatorDelete->getNumParams() == 2); 2400 } 2401 2402 if (!PointeeRD->hasIrrelevantDestructor()) 2403 if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) { 2404 MarkFunctionReferenced(StartLoc, 2405 const_cast<CXXDestructorDecl*>(Dtor)); 2406 if (DiagnoseUseOfDecl(Dtor, StartLoc)) 2407 return ExprError(); 2408 } 2409 2410 // C++ [expr.delete]p3: 2411 // In the first alternative (delete object), if the static type of the 2412 // object to be deleted is different from its dynamic type, the static 2413 // type shall be a base class of the dynamic type of the object to be 2414 // deleted and the static type shall have a virtual destructor or the 2415 // behavior is undefined. 2416 // 2417 // Note: a final class cannot be derived from, no issue there 2418 if (PointeeRD->isPolymorphic() && !PointeeRD->hasAttr<FinalAttr>()) { 2419 CXXDestructorDecl *dtor = PointeeRD->getDestructor(); 2420 if (dtor && !dtor->isVirtual()) { 2421 if (PointeeRD->isAbstract()) { 2422 // If the class is abstract, we warn by default, because we're 2423 // sure the code has undefined behavior. 2424 Diag(StartLoc, diag::warn_delete_abstract_non_virtual_dtor) 2425 << PointeeElem; 2426 } else if (!ArrayForm) { 2427 // Otherwise, if this is not an array delete, it's a bit suspect, 2428 // but not necessarily wrong. 2429 Diag(StartLoc, diag::warn_delete_non_virtual_dtor) << PointeeElem; 2430 } 2431 } 2432 } 2433 2434 } 2435 2436 if (!OperatorDelete) 2437 // Look for a global declaration. 2438 OperatorDelete = FindUsualDeallocationFunction( 2439 StartLoc, !RequireCompleteType(StartLoc, Pointee, 0) && 2440 (!ArrayForm || UsualArrayDeleteWantsSize || 2441 Pointee.isDestructedType()), 2442 DeleteName); 2443 2444 MarkFunctionReferenced(StartLoc, OperatorDelete); 2445 2446 // Check access and ambiguity of operator delete and destructor. 2447 if (PointeeRD) { 2448 if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) { 2449 CheckDestructorAccess(Ex.get()->getExprLoc(), Dtor, 2450 PDiag(diag::err_access_dtor) << PointeeElem); 2451 } 2452 } 2453 } 2454 2455 return new (Context) CXXDeleteExpr( 2456 Context.VoidTy, UseGlobal, ArrayForm, ArrayFormAsWritten, 2457 UsualArrayDeleteWantsSize, OperatorDelete, Ex.get(), StartLoc); 2458} 2459 2460/// \brief Check the use of the given variable as a C++ condition in an if, 2461/// while, do-while, or switch statement. 2462ExprResult Sema::CheckConditionVariable(VarDecl *ConditionVar, 2463 SourceLocation StmtLoc, 2464 bool ConvertToBoolean) { 2465 if (ConditionVar->isInvalidDecl()) 2466 return ExprError(); 2467 2468 QualType T = ConditionVar->getType(); 2469 2470 // C++ [stmt.select]p2: 2471 // The declarator shall not specify a function or an array. 2472 if (T->isFunctionType()) 2473 return ExprError(Diag(ConditionVar->getLocation(), 2474 diag::err_invalid_use_of_function_type) 2475 << ConditionVar->getSourceRange()); 2476 else if (T->isArrayType()) 2477 return ExprError(Diag(ConditionVar->getLocation(), 2478 diag::err_invalid_use_of_array_type) 2479 << ConditionVar->getSourceRange()); 2480 2481 ExprResult Condition = DeclRefExpr::Create( 2482 Context, NestedNameSpecifierLoc(), SourceLocation(), ConditionVar, 2483 /*enclosing*/ false, ConditionVar->getLocation(), 2484 ConditionVar->getType().getNonReferenceType(), VK_LValue); 2485 2486 MarkDeclRefReferenced(cast<DeclRefExpr>(Condition.get())); 2487 2488 if (ConvertToBoolean) { 2489 Condition = CheckBooleanCondition(Condition.get(), StmtLoc); 2490 if (Condition.isInvalid()) 2491 return ExprError(); 2492 } 2493 2494 return Condition; 2495} 2496 2497/// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid. 2498ExprResult Sema::CheckCXXBooleanCondition(Expr *CondExpr) { 2499 // C++ 6.4p4: 2500 // The value of a condition that is an initialized declaration in a statement 2501 // other than a switch statement is the value of the declared variable 2502 // implicitly converted to type bool. If that conversion is ill-formed, the 2503 // program is ill-formed. 2504 // The value of a condition that is an expression is the value of the 2505 // expression, implicitly converted to bool. 2506 // 2507 return PerformContextuallyConvertToBool(CondExpr); 2508} 2509 2510/// Helper function to determine whether this is the (deprecated) C++ 2511/// conversion from a string literal to a pointer to non-const char or 2512/// non-const wchar_t (for narrow and wide string literals, 2513/// respectively). 2514bool 2515Sema::IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType) { 2516 // Look inside the implicit cast, if it exists. 2517 if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From)) 2518 From = Cast->getSubExpr(); 2519 2520 // A string literal (2.13.4) that is not a wide string literal can 2521 // be converted to an rvalue of type "pointer to char"; a wide 2522 // string literal can be converted to an rvalue of type "pointer 2523 // to wchar_t" (C++ 4.2p2). 2524 if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From->IgnoreParens())) 2525 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) 2526 if (const BuiltinType *ToPointeeType 2527 = ToPtrType->getPointeeType()->getAs<BuiltinType>()) { 2528 // This conversion is considered only when there is an 2529 // explicit appropriate pointer target type (C++ 4.2p2). 2530 if (!ToPtrType->getPointeeType().hasQualifiers()) { 2531 switch (StrLit->getKind()) { 2532 case StringLiteral::UTF8: 2533 case StringLiteral::UTF16: 2534 case StringLiteral::UTF32: 2535 // We don't allow UTF literals to be implicitly converted 2536 break; 2537 case StringLiteral::Ascii: 2538 return (ToPointeeType->getKind() == BuiltinType::Char_U || 2539 ToPointeeType->getKind() == BuiltinType::Char_S); 2540 case StringLiteral::Wide: 2541 return ToPointeeType->isWideCharType(); 2542 } 2543 } 2544 } 2545 2546 return false; 2547} 2548 2549static ExprResult BuildCXXCastArgument(Sema &S, 2550 SourceLocation CastLoc, 2551 QualType Ty, 2552 CastKind Kind, 2553 CXXMethodDecl *Method, 2554 DeclAccessPair FoundDecl, 2555 bool HadMultipleCandidates, 2556 Expr *From) { 2557 switch (Kind) { 2558 default: llvm_unreachable("Unhandled cast kind!"); 2559 case CK_ConstructorConversion: { 2560 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Method); 2561 SmallVector<Expr*, 8> ConstructorArgs; 2562 2563 if (S.RequireNonAbstractType(CastLoc, Ty, 2564 diag::err_allocation_of_abstract_type)) 2565 return ExprError(); 2566 2567 if (S.CompleteConstructorCall(Constructor, From, CastLoc, ConstructorArgs)) 2568 return ExprError(); 2569 2570 S.CheckConstructorAccess(CastLoc, Constructor, 2571 InitializedEntity::InitializeTemporary(Ty), 2572 Constructor->getAccess()); 2573 2574 ExprResult Result = S.BuildCXXConstructExpr( 2575 CastLoc, Ty, cast<CXXConstructorDecl>(Method), 2576 ConstructorArgs, HadMultipleCandidates, 2577 /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false, 2578 CXXConstructExpr::CK_Complete, SourceRange()); 2579 if (Result.isInvalid()) 2580 return ExprError(); 2581 2582 return S.MaybeBindToTemporary(Result.getAs<Expr>()); 2583 } 2584 2585 case CK_UserDefinedConversion: { 2586 assert(!From->getType()->isPointerType() && "Arg can't have pointer type!"); 2587 2588 // Create an implicit call expr that calls it. 2589 CXXConversionDecl *Conv = cast<CXXConversionDecl>(Method); 2590 ExprResult Result = S.BuildCXXMemberCallExpr(From, FoundDecl, Conv, 2591 HadMultipleCandidates); 2592 if (Result.isInvalid()) 2593 return ExprError(); 2594 // Record usage of conversion in an implicit cast. 2595 Result = ImplicitCastExpr::Create(S.Context, Result.get()->getType(), 2596 CK_UserDefinedConversion, Result.get(), 2597 nullptr, Result.get()->getValueKind()); 2598 2599 S.CheckMemberOperatorAccess(CastLoc, From, /*arg*/ nullptr, FoundDecl); 2600 2601 return S.MaybeBindToTemporary(Result.get()); 2602 } 2603 } 2604} 2605 2606/// PerformImplicitConversion - Perform an implicit conversion of the 2607/// expression From to the type ToType using the pre-computed implicit 2608/// conversion sequence ICS. Returns the converted 2609/// expression. Action is the kind of conversion we're performing, 2610/// used in the error message. 2611ExprResult 2612Sema::PerformImplicitConversion(Expr *From, QualType ToType, 2613 const ImplicitConversionSequence &ICS, 2614 AssignmentAction Action, 2615 CheckedConversionKind CCK) { 2616 switch (ICS.getKind()) { 2617 case ImplicitConversionSequence::StandardConversion: { 2618 ExprResult Res = PerformImplicitConversion(From, ToType, ICS.Standard, 2619 Action, CCK); 2620 if (Res.isInvalid()) 2621 return ExprError(); 2622 From = Res.get(); 2623 break; 2624 } 2625 2626 case ImplicitConversionSequence::UserDefinedConversion: { 2627 2628 FunctionDecl *FD = ICS.UserDefined.ConversionFunction; 2629 CastKind CastKind; 2630 QualType BeforeToType; 2631 assert(FD && "FIXME: aggregate initialization from init list"); 2632 if (const CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(FD)) { 2633 CastKind = CK_UserDefinedConversion; 2634 2635 // If the user-defined conversion is specified by a conversion function, 2636 // the initial standard conversion sequence converts the source type to 2637 // the implicit object parameter of the conversion function. 2638 BeforeToType = Context.getTagDeclType(Conv->getParent()); 2639 } else { 2640 const CXXConstructorDecl *Ctor = cast<CXXConstructorDecl>(FD); 2641 CastKind = CK_ConstructorConversion; 2642 // Do no conversion if dealing with ... for the first conversion. 2643 if (!ICS.UserDefined.EllipsisConversion) { 2644 // If the user-defined conversion is specified by a constructor, the 2645 // initial standard conversion sequence converts the source type to 2646 // the type required by the argument of the constructor 2647 BeforeToType = Ctor->getParamDecl(0)->getType().getNonReferenceType(); 2648 } 2649 } 2650 // Watch out for ellipsis conversion. 2651 if (!ICS.UserDefined.EllipsisConversion) { 2652 ExprResult Res = 2653 PerformImplicitConversion(From, BeforeToType, 2654 ICS.UserDefined.Before, AA_Converting, 2655 CCK); 2656 if (Res.isInvalid()) 2657 return ExprError(); 2658 From = Res.get(); 2659 } 2660 2661 ExprResult CastArg 2662 = BuildCXXCastArgument(*this, 2663 From->getLocStart(), 2664 ToType.getNonReferenceType(), 2665 CastKind, cast<CXXMethodDecl>(FD), 2666 ICS.UserDefined.FoundConversionFunction, 2667 ICS.UserDefined.HadMultipleCandidates, 2668 From); 2669 2670 if (CastArg.isInvalid()) 2671 return ExprError(); 2672 2673 From = CastArg.get(); 2674 2675 return PerformImplicitConversion(From, ToType, ICS.UserDefined.After, 2676 AA_Converting, CCK); 2677 } 2678 2679 case ImplicitConversionSequence::AmbiguousConversion: 2680 ICS.DiagnoseAmbiguousConversion(*this, From->getExprLoc(), 2681 PDiag(diag::err_typecheck_ambiguous_condition) 2682 << From->getSourceRange()); 2683 return ExprError(); 2684 2685 case ImplicitConversionSequence::EllipsisConversion: 2686 llvm_unreachable("Cannot perform an ellipsis conversion"); 2687 2688 case ImplicitConversionSequence::BadConversion: 2689 return ExprError(); 2690 } 2691 2692 // Everything went well. 2693 return From; 2694} 2695 2696/// PerformImplicitConversion - Perform an implicit conversion of the 2697/// expression From to the type ToType by following the standard 2698/// conversion sequence SCS. Returns the converted 2699/// expression. Flavor is the context in which we're performing this 2700/// conversion, for use in error messages. 2701ExprResult 2702Sema::PerformImplicitConversion(Expr *From, QualType ToType, 2703 const StandardConversionSequence& SCS, 2704 AssignmentAction Action, 2705 CheckedConversionKind CCK) { 2706 bool CStyle = (CCK == CCK_CStyleCast || CCK == CCK_FunctionalCast); 2707 2708 // Overall FIXME: we are recomputing too many types here and doing far too 2709 // much extra work. What this means is that we need to keep track of more 2710 // information that is computed when we try the implicit conversion initially, 2711 // so that we don't need to recompute anything here. 2712 QualType FromType = From->getType(); 2713 2714 if (SCS.CopyConstructor) { 2715 // FIXME: When can ToType be a reference type? 2716 assert(!ToType->isReferenceType()); 2717 if (SCS.Second == ICK_Derived_To_Base) { 2718 SmallVector<Expr*, 8> ConstructorArgs; 2719 if (CompleteConstructorCall(cast<CXXConstructorDecl>(SCS.CopyConstructor), 2720 From, /*FIXME:ConstructLoc*/SourceLocation(), 2721 ConstructorArgs)) 2722 return ExprError(); 2723 return BuildCXXConstructExpr( 2724 /*FIXME:ConstructLoc*/ SourceLocation(), ToType, SCS.CopyConstructor, 2725 ConstructorArgs, /*HadMultipleCandidates*/ false, 2726 /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false, 2727 CXXConstructExpr::CK_Complete, SourceRange()); 2728 } 2729 return BuildCXXConstructExpr( 2730 /*FIXME:ConstructLoc*/ SourceLocation(), ToType, SCS.CopyConstructor, 2731 From, /*HadMultipleCandidates*/ false, 2732 /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false, 2733 CXXConstructExpr::CK_Complete, SourceRange()); 2734 } 2735 2736 // Resolve overloaded function references. 2737 if (Context.hasSameType(FromType, Context.OverloadTy)) { 2738 DeclAccessPair Found; 2739 FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(From, ToType, 2740 true, Found); 2741 if (!Fn) 2742 return ExprError(); 2743 2744 if (DiagnoseUseOfDecl(Fn, From->getLocStart())) 2745 return ExprError(); 2746 2747 From = FixOverloadedFunctionReference(From, Found, Fn); 2748 FromType = From->getType(); 2749 } 2750 2751 // If we're converting to an atomic type, first convert to the corresponding 2752 // non-atomic type. 2753 QualType ToAtomicType; 2754 if (const AtomicType *ToAtomic = ToType->getAs<AtomicType>()) { 2755 ToAtomicType = ToType; 2756 ToType = ToAtomic->getValueType(); 2757 } 2758 2759 // Perform the first implicit conversion. 2760 switch (SCS.First) { 2761 case ICK_Identity: 2762 if (const AtomicType *FromAtomic = FromType->getAs<AtomicType>()) { 2763 FromType = FromAtomic->getValueType().getUnqualifiedType(); 2764 From = ImplicitCastExpr::Create(Context, FromType, CK_AtomicToNonAtomic, 2765 From, /*BasePath=*/nullptr, VK_RValue); 2766 } 2767 break; 2768 2769 case ICK_Lvalue_To_Rvalue: { 2770 assert(From->getObjectKind() != OK_ObjCProperty); 2771 ExprResult FromRes = DefaultLvalueConversion(From); 2772 assert(!FromRes.isInvalid() && "Can't perform deduced conversion?!"); 2773 From = FromRes.get(); 2774 FromType = From->getType(); 2775 break; 2776 } 2777 2778 case ICK_Array_To_Pointer: 2779 FromType = Context.getArrayDecayedType(FromType); 2780 From = ImpCastExprToType(From, FromType, CK_ArrayToPointerDecay, 2781 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2782 break; 2783 2784 case ICK_Function_To_Pointer: 2785 FromType = Context.getPointerType(FromType); 2786 From = ImpCastExprToType(From, FromType, CK_FunctionToPointerDecay, 2787 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2788 break; 2789 2790 default: 2791 llvm_unreachable("Improper first standard conversion"); 2792 } 2793 2794 // Perform the second implicit conversion 2795 switch (SCS.Second) { 2796 case ICK_Identity: 2797 // C++ [except.spec]p5: 2798 // [For] assignment to and initialization of pointers to functions, 2799 // pointers to member functions, and references to functions: the 2800 // target entity shall allow at least the exceptions allowed by the 2801 // source value in the assignment or initialization. 2802 switch (Action) { 2803 case AA_Assigning: 2804 case AA_Initializing: 2805 // Note, function argument passing and returning are initialization. 2806 case AA_Passing: 2807 case AA_Returning: 2808 case AA_Sending: 2809 case AA_Passing_CFAudited: 2810 if (CheckExceptionSpecCompatibility(From, ToType)) 2811 return ExprError(); 2812 break; 2813 2814 case AA_Casting: 2815 case AA_Converting: 2816 // Casts and implicit conversions are not initialization, so are not 2817 // checked for exception specification mismatches. 2818 break; 2819 } 2820 // Nothing else to do. 2821 break; 2822 2823 case ICK_NoReturn_Adjustment: 2824 // If both sides are functions (or pointers/references to them), there could 2825 // be incompatible exception declarations. 2826 if (CheckExceptionSpecCompatibility(From, ToType)) 2827 return ExprError(); 2828 2829 From = ImpCastExprToType(From, ToType, CK_NoOp, 2830 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2831 break; 2832 2833 case ICK_Integral_Promotion: 2834 case ICK_Integral_Conversion: 2835 if (ToType->isBooleanType()) { 2836 assert(FromType->castAs<EnumType>()->getDecl()->isFixed() && 2837 SCS.Second == ICK_Integral_Promotion && 2838 "only enums with fixed underlying type can promote to bool"); 2839 From = ImpCastExprToType(From, ToType, CK_IntegralToBoolean, 2840 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2841 } else { 2842 From = ImpCastExprToType(From, ToType, CK_IntegralCast, 2843 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2844 } 2845 break; 2846 2847 case ICK_Floating_Promotion: 2848 case ICK_Floating_Conversion: 2849 From = ImpCastExprToType(From, ToType, CK_FloatingCast, 2850 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2851 break; 2852 2853 case ICK_Complex_Promotion: 2854 case ICK_Complex_Conversion: { 2855 QualType FromEl = From->getType()->getAs<ComplexType>()->getElementType(); 2856 QualType ToEl = ToType->getAs<ComplexType>()->getElementType(); 2857 CastKind CK; 2858 if (FromEl->isRealFloatingType()) { 2859 if (ToEl->isRealFloatingType()) 2860 CK = CK_FloatingComplexCast; 2861 else 2862 CK = CK_FloatingComplexToIntegralComplex; 2863 } else if (ToEl->isRealFloatingType()) { 2864 CK = CK_IntegralComplexToFloatingComplex; 2865 } else { 2866 CK = CK_IntegralComplexCast; 2867 } 2868 From = ImpCastExprToType(From, ToType, CK, 2869 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2870 break; 2871 } 2872 2873 case ICK_Floating_Integral: 2874 if (ToType->isRealFloatingType()) 2875 From = ImpCastExprToType(From, ToType, CK_IntegralToFloating, 2876 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2877 else 2878 From = ImpCastExprToType(From, ToType, CK_FloatingToIntegral, 2879 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2880 break; 2881 2882 case ICK_Compatible_Conversion: 2883 From = ImpCastExprToType(From, ToType, CK_NoOp, 2884 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2885 break; 2886 2887 case ICK_Writeback_Conversion: 2888 case ICK_Pointer_Conversion: { 2889 if (SCS.IncompatibleObjC && Action != AA_Casting) { 2890 // Diagnose incompatible Objective-C conversions 2891 if (Action == AA_Initializing || Action == AA_Assigning) 2892 Diag(From->getLocStart(), 2893 diag::ext_typecheck_convert_incompatible_pointer) 2894 << ToType << From->getType() << Action 2895 << From->getSourceRange() << 0; 2896 else 2897 Diag(From->getLocStart(), 2898 diag::ext_typecheck_convert_incompatible_pointer) 2899 << From->getType() << ToType << Action 2900 << From->getSourceRange() << 0; 2901 2902 if (From->getType()->isObjCObjectPointerType() && 2903 ToType->isObjCObjectPointerType()) 2904 EmitRelatedResultTypeNote(From); 2905 } 2906 else if (getLangOpts().ObjCAutoRefCount && 2907 !CheckObjCARCUnavailableWeakConversion(ToType, 2908 From->getType())) { 2909 if (Action == AA_Initializing) 2910 Diag(From->getLocStart(), 2911 diag::err_arc_weak_unavailable_assign); 2912 else 2913 Diag(From->getLocStart(), 2914 diag::err_arc_convesion_of_weak_unavailable) 2915 << (Action == AA_Casting) << From->getType() << ToType 2916 << From->getSourceRange(); 2917 } 2918 2919 CastKind Kind = CK_Invalid; 2920 CXXCastPath BasePath; 2921 if (CheckPointerConversion(From, ToType, Kind, BasePath, CStyle)) 2922 return ExprError(); 2923 2924 // Make sure we extend blocks if necessary. 2925 // FIXME: doing this here is really ugly. 2926 if (Kind == CK_BlockPointerToObjCPointerCast) { 2927 ExprResult E = From; 2928 (void) PrepareCastToObjCObjectPointer(E); 2929 From = E.get(); 2930 } 2931 if (getLangOpts().ObjCAutoRefCount) 2932 CheckObjCARCConversion(SourceRange(), ToType, From, CCK); 2933 From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK) 2934 .get(); 2935 break; 2936 } 2937 2938 case ICK_Pointer_Member: { 2939 CastKind Kind = CK_Invalid; 2940 CXXCastPath BasePath; 2941 if (CheckMemberPointerConversion(From, ToType, Kind, BasePath, CStyle)) 2942 return ExprError(); 2943 if (CheckExceptionSpecCompatibility(From, ToType)) 2944 return ExprError(); 2945 2946 // We may not have been able to figure out what this member pointer resolved 2947 // to up until this exact point. Attempt to lock-in it's inheritance model. 2948 QualType FromType = From->getType(); 2949 if (FromType->isMemberPointerType()) 2950 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) 2951 RequireCompleteType(From->getExprLoc(), FromType, 0); 2952 2953 From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK) 2954 .get(); 2955 break; 2956 } 2957 2958 case ICK_Boolean_Conversion: 2959 // Perform half-to-boolean conversion via float. 2960 if (From->getType()->isHalfType()) { 2961 From = ImpCastExprToType(From, Context.FloatTy, CK_FloatingCast).get(); 2962 FromType = Context.FloatTy; 2963 } 2964 2965 From = ImpCastExprToType(From, Context.BoolTy, 2966 ScalarTypeToBooleanCastKind(FromType), 2967 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2968 break; 2969 2970 case ICK_Derived_To_Base: { 2971 CXXCastPath BasePath; 2972 if (CheckDerivedToBaseConversion(From->getType(), 2973 ToType.getNonReferenceType(), 2974 From->getLocStart(), 2975 From->getSourceRange(), 2976 &BasePath, 2977 CStyle)) 2978 return ExprError(); 2979 2980 From = ImpCastExprToType(From, ToType.getNonReferenceType(), 2981 CK_DerivedToBase, From->getValueKind(), 2982 &BasePath, CCK).get(); 2983 break; 2984 } 2985 2986 case ICK_Vector_Conversion: 2987 From = ImpCastExprToType(From, ToType, CK_BitCast, 2988 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2989 break; 2990 2991 case ICK_Vector_Splat: 2992 From = ImpCastExprToType(From, ToType, CK_VectorSplat, 2993 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2994 break; 2995 2996 case ICK_Complex_Real: 2997 // Case 1. x -> _Complex y 2998 if (const ComplexType *ToComplex = ToType->getAs<ComplexType>()) { 2999 QualType ElType = ToComplex->getElementType(); 3000 bool isFloatingComplex = ElType->isRealFloatingType(); 3001 3002 // x -> y 3003 if (Context.hasSameUnqualifiedType(ElType, From->getType())) { 3004 // do nothing 3005 } else if (From->getType()->isRealFloatingType()) { 3006 From = ImpCastExprToType(From, ElType, 3007 isFloatingComplex ? CK_FloatingCast : CK_FloatingToIntegral).get(); 3008 } else { 3009 assert(From->getType()->isIntegerType()); 3010 From = ImpCastExprToType(From, ElType, 3011 isFloatingComplex ? CK_IntegralToFloating : CK_IntegralCast).get(); 3012 } 3013 // y -> _Complex y 3014 From = ImpCastExprToType(From, ToType, 3015 isFloatingComplex ? CK_FloatingRealToComplex 3016 : CK_IntegralRealToComplex).get(); 3017 3018 // Case 2. _Complex x -> y 3019 } else { 3020 const ComplexType *FromComplex = From->getType()->getAs<ComplexType>(); 3021 assert(FromComplex); 3022 3023 QualType ElType = FromComplex->getElementType(); 3024 bool isFloatingComplex = ElType->isRealFloatingType(); 3025 3026 // _Complex x -> x 3027 From = ImpCastExprToType(From, ElType, 3028 isFloatingComplex ? CK_FloatingComplexToReal 3029 : CK_IntegralComplexToReal, 3030 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 3031 3032 // x -> y 3033 if (Context.hasSameUnqualifiedType(ElType, ToType)) { 3034 // do nothing 3035 } else if (ToType->isRealFloatingType()) { 3036 From = ImpCastExprToType(From, ToType, 3037 isFloatingComplex ? CK_FloatingCast : CK_IntegralToFloating, 3038 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 3039 } else { 3040 assert(ToType->isIntegerType()); 3041 From = ImpCastExprToType(From, ToType, 3042 isFloatingComplex ? CK_FloatingToIntegral : CK_IntegralCast, 3043 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 3044 } 3045 } 3046 break; 3047 3048 case ICK_Block_Pointer_Conversion: { 3049 From = ImpCastExprToType(From, ToType.getUnqualifiedType(), CK_BitCast, 3050 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 3051 break; 3052 } 3053 3054 case ICK_TransparentUnionConversion: { 3055 ExprResult FromRes = From; 3056 Sema::AssignConvertType ConvTy = 3057 CheckTransparentUnionArgumentConstraints(ToType, FromRes); 3058 if (FromRes.isInvalid()) 3059 return ExprError(); 3060 From = FromRes.get(); 3061 assert ((ConvTy == Sema::Compatible) && 3062 "Improper transparent union conversion"); 3063 (void)ConvTy; 3064 break; 3065 } 3066 3067 case ICK_Zero_Event_Conversion: 3068 From = ImpCastExprToType(From, ToType, 3069 CK_ZeroToOCLEvent, 3070 From->getValueKind()).get(); 3071 break; 3072 3073 case ICK_Lvalue_To_Rvalue: 3074 case ICK_Array_To_Pointer: 3075 case ICK_Function_To_Pointer: 3076 case ICK_Qualification: 3077 case ICK_Num_Conversion_Kinds: 3078 llvm_unreachable("Improper second standard conversion"); 3079 } 3080 3081 switch (SCS.Third) { 3082 case ICK_Identity: 3083 // Nothing to do. 3084 break; 3085 3086 case ICK_Qualification: { 3087 // The qualification keeps the category of the inner expression, unless the 3088 // target type isn't a reference. 3089 ExprValueKind VK = ToType->isReferenceType() ? 3090 From->getValueKind() : VK_RValue; 3091 From = ImpCastExprToType(From, ToType.getNonLValueExprType(Context), 3092 CK_NoOp, VK, /*BasePath=*/nullptr, CCK).get(); 3093 3094 if (SCS.DeprecatedStringLiteralToCharPtr && 3095 !getLangOpts().WritableStrings) { 3096 Diag(From->getLocStart(), getLangOpts().CPlusPlus11 3097 ? diag::ext_deprecated_string_literal_conversion 3098 : diag::warn_deprecated_string_literal_conversion) 3099 << ToType.getNonReferenceType(); 3100 } 3101 3102 break; 3103 } 3104 3105 default: 3106 llvm_unreachable("Improper third standard conversion"); 3107 } 3108 3109 // If this conversion sequence involved a scalar -> atomic conversion, perform 3110 // that conversion now. 3111 if (!ToAtomicType.isNull()) { 3112 assert(Context.hasSameType( 3113 ToAtomicType->castAs<AtomicType>()->getValueType(), From->getType())); 3114 From = ImpCastExprToType(From, ToAtomicType, CK_NonAtomicToAtomic, 3115 VK_RValue, nullptr, CCK).get(); 3116 } 3117 3118 return From; 3119} 3120 3121/// \brief Check the completeness of a type in a unary type trait. 3122/// 3123/// If the particular type trait requires a complete type, tries to complete 3124/// it. If completing the type fails, a diagnostic is emitted and false 3125/// returned. If completing the type succeeds or no completion was required, 3126/// returns true. 3127static bool CheckUnaryTypeTraitTypeCompleteness(Sema &S, TypeTrait UTT, 3128 SourceLocation Loc, 3129 QualType ArgTy) { 3130 // C++0x [meta.unary.prop]p3: 3131 // For all of the class templates X declared in this Clause, instantiating 3132 // that template with a template argument that is a class template 3133 // specialization may result in the implicit instantiation of the template 3134 // argument if and only if the semantics of X require that the argument 3135 // must be a complete type. 3136 // We apply this rule to all the type trait expressions used to implement 3137 // these class templates. We also try to follow any GCC documented behavior 3138 // in these expressions to ensure portability of standard libraries. 3139 switch (UTT) { 3140 default: llvm_unreachable("not a UTT"); 3141 // is_complete_type somewhat obviously cannot require a complete type. 3142 case UTT_IsCompleteType: 3143 // Fall-through 3144 3145 // These traits are modeled on the type predicates in C++0x 3146 // [meta.unary.cat] and [meta.unary.comp]. They are not specified as 3147 // requiring a complete type, as whether or not they return true cannot be 3148 // impacted by the completeness of the type. 3149 case UTT_IsVoid: 3150 case UTT_IsIntegral: 3151 case UTT_IsFloatingPoint: 3152 case UTT_IsArray: 3153 case UTT_IsPointer: 3154 case UTT_IsLvalueReference: 3155 case UTT_IsRvalueReference: 3156 case UTT_IsMemberFunctionPointer: 3157 case UTT_IsMemberObjectPointer: 3158 case UTT_IsEnum: 3159 case UTT_IsUnion: 3160 case UTT_IsClass: 3161 case UTT_IsFunction: 3162 case UTT_IsReference: 3163 case UTT_IsArithmetic: 3164 case UTT_IsFundamental: 3165 case UTT_IsObject: 3166 case UTT_IsScalar: 3167 case UTT_IsCompound: 3168 case UTT_IsMemberPointer: 3169 // Fall-through 3170 3171 // These traits are modeled on type predicates in C++0x [meta.unary.prop] 3172 // which requires some of its traits to have the complete type. However, 3173 // the completeness of the type cannot impact these traits' semantics, and 3174 // so they don't require it. This matches the comments on these traits in 3175 // Table 49. 3176 case UTT_IsConst: 3177 case UTT_IsVolatile: 3178 case UTT_IsSigned: 3179 case UTT_IsUnsigned: 3180 return true; 3181 3182 // C++0x [meta.unary.prop] Table 49 requires the following traits to be 3183 // applied to a complete type. 3184 case UTT_IsTrivial: 3185 case UTT_IsTriviallyCopyable: 3186 case UTT_IsStandardLayout: 3187 case UTT_IsPOD: 3188 case UTT_IsLiteral: 3189 case UTT_IsEmpty: 3190 case UTT_IsPolymorphic: 3191 case UTT_IsAbstract: 3192 case UTT_IsInterfaceClass: 3193 case UTT_IsDestructible: 3194 case UTT_IsNothrowDestructible: 3195 // Fall-through 3196 3197 // These traits require a complete type. 3198 case UTT_IsFinal: 3199 case UTT_IsSealed: 3200 3201 // These trait expressions are designed to help implement predicates in 3202 // [meta.unary.prop] despite not being named the same. They are specified 3203 // by both GCC and the Embarcadero C++ compiler, and require the complete 3204 // type due to the overarching C++0x type predicates being implemented 3205 // requiring the complete type. 3206 case UTT_HasNothrowAssign: 3207 case UTT_HasNothrowMoveAssign: 3208 case UTT_HasNothrowConstructor: 3209 case UTT_HasNothrowCopy: 3210 case UTT_HasTrivialAssign: 3211 case UTT_HasTrivialMoveAssign: 3212 case UTT_HasTrivialDefaultConstructor: 3213 case UTT_HasTrivialMoveConstructor: 3214 case UTT_HasTrivialCopy: 3215 case UTT_HasTrivialDestructor: 3216 case UTT_HasVirtualDestructor: 3217 // Arrays of unknown bound are expressly allowed. 3218 QualType ElTy = ArgTy; 3219 if (ArgTy->isIncompleteArrayType()) 3220 ElTy = S.Context.getAsArrayType(ArgTy)->getElementType(); 3221 3222 // The void type is expressly allowed. 3223 if (ElTy->isVoidType()) 3224 return true; 3225 3226 return !S.RequireCompleteType( 3227 Loc, ElTy, diag::err_incomplete_type_used_in_type_trait_expr); 3228 } 3229} 3230 3231static bool HasNoThrowOperator(const RecordType *RT, OverloadedOperatorKind Op, 3232 Sema &Self, SourceLocation KeyLoc, ASTContext &C, 3233 bool (CXXRecordDecl::*HasTrivial)() const, 3234 bool (CXXRecordDecl::*HasNonTrivial)() const, 3235 bool (CXXMethodDecl::*IsDesiredOp)() const) 3236{ 3237 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 3238 if ((RD->*HasTrivial)() && !(RD->*HasNonTrivial)()) 3239 return true; 3240 3241 DeclarationName Name = C.DeclarationNames.getCXXOperatorName(Op); 3242 DeclarationNameInfo NameInfo(Name, KeyLoc); 3243 LookupResult Res(Self, NameInfo, Sema::LookupOrdinaryName); 3244 if (Self.LookupQualifiedName(Res, RD)) { 3245 bool FoundOperator = false; 3246 Res.suppressDiagnostics(); 3247 for (LookupResult::iterator Op = Res.begin(), OpEnd = Res.end(); 3248 Op != OpEnd; ++Op) { 3249 if (isa<FunctionTemplateDecl>(*Op)) 3250 continue; 3251 3252 CXXMethodDecl *Operator = cast<CXXMethodDecl>(*Op); 3253 if((Operator->*IsDesiredOp)()) { 3254 FoundOperator = true; 3255 const FunctionProtoType *CPT = 3256 Operator->getType()->getAs<FunctionProtoType>(); 3257 CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); 3258 if (!CPT || !CPT->isNothrow(C)) 3259 return false; 3260 } 3261 } 3262 return FoundOperator; 3263 } 3264 return false; 3265} 3266 3267static bool EvaluateUnaryTypeTrait(Sema &Self, TypeTrait UTT, 3268 SourceLocation KeyLoc, QualType T) { 3269 assert(!T->isDependentType() && "Cannot evaluate traits of dependent type"); 3270 3271 ASTContext &C = Self.Context; 3272 switch(UTT) { 3273 default: llvm_unreachable("not a UTT"); 3274 // Type trait expressions corresponding to the primary type category 3275 // predicates in C++0x [meta.unary.cat]. 3276 case UTT_IsVoid: 3277 return T->isVoidType(); 3278 case UTT_IsIntegral: 3279 return T->isIntegralType(C); 3280 case UTT_IsFloatingPoint: 3281 return T->isFloatingType(); 3282 case UTT_IsArray: 3283 return T->isArrayType(); 3284 case UTT_IsPointer: 3285 return T->isPointerType(); 3286 case UTT_IsLvalueReference: 3287 return T->isLValueReferenceType(); 3288 case UTT_IsRvalueReference: 3289 return T->isRValueReferenceType(); 3290 case UTT_IsMemberFunctionPointer: 3291 return T->isMemberFunctionPointerType(); 3292 case UTT_IsMemberObjectPointer: 3293 return T->isMemberDataPointerType(); 3294 case UTT_IsEnum: 3295 return T->isEnumeralType(); 3296 case UTT_IsUnion: 3297 return T->isUnionType(); 3298 case UTT_IsClass: 3299 return T->isClassType() || T->isStructureType() || T->isInterfaceType(); 3300 case UTT_IsFunction: 3301 return T->isFunctionType(); 3302 3303 // Type trait expressions which correspond to the convenient composition 3304 // predicates in C++0x [meta.unary.comp]. 3305 case UTT_IsReference: 3306 return T->isReferenceType(); 3307 case UTT_IsArithmetic: 3308 return T->isArithmeticType() && !T->isEnumeralType(); 3309 case UTT_IsFundamental: 3310 return T->isFundamentalType(); 3311 case UTT_IsObject: 3312 return T->isObjectType(); 3313 case UTT_IsScalar: 3314 // Note: semantic analysis depends on Objective-C lifetime types to be 3315 // considered scalar types. However, such types do not actually behave 3316 // like scalar types at run time (since they may require retain/release 3317 // operations), so we report them as non-scalar. 3318 if (T->isObjCLifetimeType()) { 3319 switch (T.getObjCLifetime()) { 3320 case Qualifiers::OCL_None: 3321 case Qualifiers::OCL_ExplicitNone: 3322 return true; 3323 3324 case Qualifiers::OCL_Strong: 3325 case Qualifiers::OCL_Weak: 3326 case Qualifiers::OCL_Autoreleasing: 3327 return false; 3328 } 3329 } 3330 3331 return T->isScalarType(); 3332 case UTT_IsCompound: 3333 return T->isCompoundType(); 3334 case UTT_IsMemberPointer: 3335 return T->isMemberPointerType(); 3336 3337 // Type trait expressions which correspond to the type property predicates 3338 // in C++0x [meta.unary.prop]. 3339 case UTT_IsConst: 3340 return T.isConstQualified(); 3341 case UTT_IsVolatile: 3342 return T.isVolatileQualified(); 3343 case UTT_IsTrivial: 3344 return T.isTrivialType(Self.Context); 3345 case UTT_IsTriviallyCopyable: 3346 return T.isTriviallyCopyableType(Self.Context); 3347 case UTT_IsStandardLayout: 3348 return T->isStandardLayoutType(); 3349 case UTT_IsPOD: 3350 return T.isPODType(Self.Context); 3351 case UTT_IsLiteral: 3352 return T->isLiteralType(Self.Context); 3353 case UTT_IsEmpty: 3354 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 3355 return !RD->isUnion() && RD->isEmpty(); 3356 return false; 3357 case UTT_IsPolymorphic: 3358 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 3359 return RD->isPolymorphic(); 3360 return false; 3361 case UTT_IsAbstract: 3362 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 3363 return RD->isAbstract(); 3364 return false; 3365 case UTT_IsInterfaceClass: 3366 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 3367 return RD->isInterface(); 3368 return false; 3369 case UTT_IsFinal: 3370 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 3371 return RD->hasAttr<FinalAttr>(); 3372 return false; 3373 case UTT_IsSealed: 3374 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 3375 if (FinalAttr *FA = RD->getAttr<FinalAttr>()) 3376 return FA->isSpelledAsSealed(); 3377 return false; 3378 case UTT_IsSigned: 3379 return T->isSignedIntegerType(); 3380 case UTT_IsUnsigned: 3381 return T->isUnsignedIntegerType(); 3382 3383 // Type trait expressions which query classes regarding their construction, 3384 // destruction, and copying. Rather than being based directly on the 3385 // related type predicates in the standard, they are specified by both 3386 // GCC[1] and the Embarcadero C++ compiler[2], and Clang implements those 3387 // specifications. 3388 // 3389 // 1: http://gcc.gnu/.org/onlinedocs/gcc/Type-Traits.html 3390 // 2: http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index 3391 // 3392 // Note that these builtins do not behave as documented in g++: if a class 3393 // has both a trivial and a non-trivial special member of a particular kind, 3394 // they return false! For now, we emulate this behavior. 3395 // FIXME: This appears to be a g++ bug: more complex cases reveal that it 3396 // does not correctly compute triviality in the presence of multiple special 3397 // members of the same kind. Revisit this once the g++ bug is fixed. 3398 case UTT_HasTrivialDefaultConstructor: 3399 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3400 // If __is_pod (type) is true then the trait is true, else if type is 3401 // a cv class or union type (or array thereof) with a trivial default 3402 // constructor ([class.ctor]) then the trait is true, else it is false. 3403 if (T.isPODType(Self.Context)) 3404 return true; 3405 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) 3406 return RD->hasTrivialDefaultConstructor() && 3407 !RD->hasNonTrivialDefaultConstructor(); 3408 return false; 3409 case UTT_HasTrivialMoveConstructor: 3410 // This trait is implemented by MSVC 2012 and needed to parse the 3411 // standard library headers. Specifically this is used as the logic 3412 // behind std::is_trivially_move_constructible (20.9.4.3). 3413 if (T.isPODType(Self.Context)) 3414 return true; 3415 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) 3416 return RD->hasTrivialMoveConstructor() && !RD->hasNonTrivialMoveConstructor(); 3417 return false; 3418 case UTT_HasTrivialCopy: 3419 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3420 // If __is_pod (type) is true or type is a reference type then 3421 // the trait is true, else if type is a cv class or union type 3422 // with a trivial copy constructor ([class.copy]) then the trait 3423 // is true, else it is false. 3424 if (T.isPODType(Self.Context) || T->isReferenceType()) 3425 return true; 3426 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 3427 return RD->hasTrivialCopyConstructor() && 3428 !RD->hasNonTrivialCopyConstructor(); 3429 return false; 3430 case UTT_HasTrivialMoveAssign: 3431 // This trait is implemented by MSVC 2012 and needed to parse the 3432 // standard library headers. Specifically it is used as the logic 3433 // behind std::is_trivially_move_assignable (20.9.4.3) 3434 if (T.isPODType(Self.Context)) 3435 return true; 3436 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) 3437 return RD->hasTrivialMoveAssignment() && !RD->hasNonTrivialMoveAssignment(); 3438 return false; 3439 case UTT_HasTrivialAssign: 3440 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3441 // If type is const qualified or is a reference type then the 3442 // trait is false. Otherwise if __is_pod (type) is true then the 3443 // trait is true, else if type is a cv class or union type with 3444 // a trivial copy assignment ([class.copy]) then the trait is 3445 // true, else it is false. 3446 // Note: the const and reference restrictions are interesting, 3447 // given that const and reference members don't prevent a class 3448 // from having a trivial copy assignment operator (but do cause 3449 // errors if the copy assignment operator is actually used, q.v. 3450 // [class.copy]p12). 3451 3452 if (T.isConstQualified()) 3453 return false; 3454 if (T.isPODType(Self.Context)) 3455 return true; 3456 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 3457 return RD->hasTrivialCopyAssignment() && 3458 !RD->hasNonTrivialCopyAssignment(); 3459 return false; 3460 case UTT_IsDestructible: 3461 case UTT_IsNothrowDestructible: 3462 // FIXME: Implement UTT_IsDestructible and UTT_IsNothrowDestructible. 3463 // For now, let's fall through. 3464 case UTT_HasTrivialDestructor: 3465 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html 3466 // If __is_pod (type) is true or type is a reference type 3467 // then the trait is true, else if type is a cv class or union 3468 // type (or array thereof) with a trivial destructor 3469 // ([class.dtor]) then the trait is true, else it is 3470 // false. 3471 if (T.isPODType(Self.Context) || T->isReferenceType()) 3472 return true; 3473 3474 // Objective-C++ ARC: autorelease types don't require destruction. 3475 if (T->isObjCLifetimeType() && 3476 T.getObjCLifetime() == Qualifiers::OCL_Autoreleasing) 3477 return true; 3478 3479 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) 3480 return RD->hasTrivialDestructor(); 3481 return false; 3482 // TODO: Propagate nothrowness for implicitly declared special members. 3483 case UTT_HasNothrowAssign: 3484 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3485 // If type is const qualified or is a reference type then the 3486 // trait is false. Otherwise if __has_trivial_assign (type) 3487 // is true then the trait is true, else if type is a cv class 3488 // or union type with copy assignment operators that are known 3489 // not to throw an exception then the trait is true, else it is 3490 // false. 3491 if (C.getBaseElementType(T).isConstQualified()) 3492 return false; 3493 if (T->isReferenceType()) 3494 return false; 3495 if (T.isPODType(Self.Context) || T->isObjCLifetimeType()) 3496 return true; 3497 3498 if (const RecordType *RT = T->getAs<RecordType>()) 3499 return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C, 3500 &CXXRecordDecl::hasTrivialCopyAssignment, 3501 &CXXRecordDecl::hasNonTrivialCopyAssignment, 3502 &CXXMethodDecl::isCopyAssignmentOperator); 3503 return false; 3504 case UTT_HasNothrowMoveAssign: 3505 // This trait is implemented by MSVC 2012 and needed to parse the 3506 // standard library headers. Specifically this is used as the logic 3507 // behind std::is_nothrow_move_assignable (20.9.4.3). 3508 if (T.isPODType(Self.Context)) 3509 return true; 3510 3511 if (const RecordType *RT = C.getBaseElementType(T)->getAs<RecordType>()) 3512 return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C, 3513 &CXXRecordDecl::hasTrivialMoveAssignment, 3514 &CXXRecordDecl::hasNonTrivialMoveAssignment, 3515 &CXXMethodDecl::isMoveAssignmentOperator); 3516 return false; 3517 case UTT_HasNothrowCopy: 3518 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3519 // If __has_trivial_copy (type) is true then the trait is true, else 3520 // if type is a cv class or union type with copy constructors that are 3521 // known not to throw an exception then the trait is true, else it is 3522 // false. 3523 if (T.isPODType(C) || T->isReferenceType() || T->isObjCLifetimeType()) 3524 return true; 3525 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) { 3526 if (RD->hasTrivialCopyConstructor() && 3527 !RD->hasNonTrivialCopyConstructor()) 3528 return true; 3529 3530 bool FoundConstructor = false; 3531 unsigned FoundTQs; 3532 DeclContext::lookup_const_result R = Self.LookupConstructors(RD); 3533 for (DeclContext::lookup_const_iterator Con = R.begin(), 3534 ConEnd = R.end(); Con != ConEnd; ++Con) { 3535 // A template constructor is never a copy constructor. 3536 // FIXME: However, it may actually be selected at the actual overload 3537 // resolution point. 3538 if (isa<FunctionTemplateDecl>(*Con)) 3539 continue; 3540 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con); 3541 if (Constructor->isCopyConstructor(FoundTQs)) { 3542 FoundConstructor = true; 3543 const FunctionProtoType *CPT 3544 = Constructor->getType()->getAs<FunctionProtoType>(); 3545 CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); 3546 if (!CPT) 3547 return false; 3548 // TODO: check whether evaluating default arguments can throw. 3549 // For now, we'll be conservative and assume that they can throw. 3550 if (!CPT->isNothrow(Self.Context) || CPT->getNumParams() > 1) 3551 return false; 3552 } 3553 } 3554 3555 return FoundConstructor; 3556 } 3557 return false; 3558 case UTT_HasNothrowConstructor: 3559 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html 3560 // If __has_trivial_constructor (type) is true then the trait is 3561 // true, else if type is a cv class or union type (or array 3562 // thereof) with a default constructor that is known not to 3563 // throw an exception then the trait is true, else it is false. 3564 if (T.isPODType(C) || T->isObjCLifetimeType()) 3565 return true; 3566 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) { 3567 if (RD->hasTrivialDefaultConstructor() && 3568 !RD->hasNonTrivialDefaultConstructor()) 3569 return true; 3570 3571 bool FoundConstructor = false; 3572 DeclContext::lookup_const_result R = Self.LookupConstructors(RD); 3573 for (DeclContext::lookup_const_iterator Con = R.begin(), 3574 ConEnd = R.end(); Con != ConEnd; ++Con) { 3575 // FIXME: In C++0x, a constructor template can be a default constructor. 3576 if (isa<FunctionTemplateDecl>(*Con)) 3577 continue; 3578 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con); 3579 if (Constructor->isDefaultConstructor()) { 3580 FoundConstructor = true; 3581 const FunctionProtoType *CPT 3582 = Constructor->getType()->getAs<FunctionProtoType>(); 3583 CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); 3584 if (!CPT) 3585 return false; 3586 // FIXME: check whether evaluating default arguments can throw. 3587 // For now, we'll be conservative and assume that they can throw. 3588 if (!CPT->isNothrow(Self.Context) || CPT->getNumParams() > 0) 3589 return false; 3590 } 3591 } 3592 return FoundConstructor; 3593 } 3594 return false; 3595 case UTT_HasVirtualDestructor: 3596 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3597 // If type is a class type with a virtual destructor ([class.dtor]) 3598 // then the trait is true, else it is false. 3599 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 3600 if (CXXDestructorDecl *Destructor = Self.LookupDestructor(RD)) 3601 return Destructor->isVirtual(); 3602 return false; 3603 3604 // These type trait expressions are modeled on the specifications for the 3605 // Embarcadero C++0x type trait functions: 3606 // http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index 3607 case UTT_IsCompleteType: 3608 // http://docwiki.embarcadero.com/RADStudio/XE/en/Is_complete_type_(typename_T_): 3609 // Returns True if and only if T is a complete type at the point of the 3610 // function call. 3611 return !T->isIncompleteType(); 3612 } 3613} 3614 3615/// \brief Determine whether T has a non-trivial Objective-C lifetime in 3616/// ARC mode. 3617static bool hasNontrivialObjCLifetime(QualType T) { 3618 switch (T.getObjCLifetime()) { 3619 case Qualifiers::OCL_ExplicitNone: 3620 return false; 3621 3622 case Qualifiers::OCL_Strong: 3623 case Qualifiers::OCL_Weak: 3624 case Qualifiers::OCL_Autoreleasing: 3625 return true; 3626 3627 case Qualifiers::OCL_None: 3628 return T->isObjCLifetimeType(); 3629 } 3630 3631 llvm_unreachable("Unknown ObjC lifetime qualifier"); 3632} 3633 3634static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT, 3635 QualType RhsT, SourceLocation KeyLoc); 3636 3637static bool evaluateTypeTrait(Sema &S, TypeTrait Kind, SourceLocation KWLoc, 3638 ArrayRef<TypeSourceInfo *> Args, 3639 SourceLocation RParenLoc) { 3640 if (Kind <= UTT_Last) 3641 return EvaluateUnaryTypeTrait(S, Kind, KWLoc, Args[0]->getType()); 3642 3643 if (Kind <= BTT_Last) 3644 return EvaluateBinaryTypeTrait(S, Kind, Args[0]->getType(), 3645 Args[1]->getType(), RParenLoc); 3646 3647 switch (Kind) { 3648 case clang::TT_IsConstructible: 3649 case clang::TT_IsNothrowConstructible: 3650 case clang::TT_IsTriviallyConstructible: { 3651 // C++11 [meta.unary.prop]: 3652 // is_trivially_constructible is defined as: 3653 // 3654 // is_constructible<T, Args...>::value is true and the variable 3655 // definition for is_constructible, as defined below, is known to call 3656 // no operation that is not trivial. 3657 // 3658 // The predicate condition for a template specialization 3659 // is_constructible<T, Args...> shall be satisfied if and only if the 3660 // following variable definition would be well-formed for some invented 3661 // variable t: 3662 // 3663 // T t(create<Args>()...); 3664 assert(!Args.empty()); 3665 3666 // Precondition: T and all types in the parameter pack Args shall be 3667 // complete types, (possibly cv-qualified) void, or arrays of 3668 // unknown bound. 3669 for (unsigned I = 0, N = Args.size(); I != N; ++I) { 3670 QualType ArgTy = Args[I]->getType(); 3671 if (ArgTy->isVoidType() || ArgTy->isIncompleteArrayType()) 3672 continue; 3673 3674 if (S.RequireCompleteType(KWLoc, ArgTy, 3675 diag::err_incomplete_type_used_in_type_trait_expr)) 3676 return false; 3677 } 3678 3679 // Make sure the first argument is a complete type. 3680 if (Args[0]->getType()->isIncompleteType()) 3681 return false; 3682 3683 // Make sure the first argument is not an abstract type. 3684 CXXRecordDecl *RD = Args[0]->getType()->getAsCXXRecordDecl(); 3685 if (RD && RD->isAbstract()) 3686 return false; 3687 3688 SmallVector<OpaqueValueExpr, 2> OpaqueArgExprs; 3689 SmallVector<Expr *, 2> ArgExprs; 3690 ArgExprs.reserve(Args.size() - 1); 3691 for (unsigned I = 1, N = Args.size(); I != N; ++I) { 3692 QualType T = Args[I]->getType(); 3693 if (T->isObjectType() || T->isFunctionType()) 3694 T = S.Context.getRValueReferenceType(T); 3695 OpaqueArgExprs.push_back( 3696 OpaqueValueExpr(Args[I]->getTypeLoc().getLocStart(), 3697 T.getNonLValueExprType(S.Context), 3698 Expr::getValueKindForType(T))); 3699 } 3700 for (Expr &E : OpaqueArgExprs) 3701 ArgExprs.push_back(&E); 3702 3703 // Perform the initialization in an unevaluated context within a SFINAE 3704 // trap at translation unit scope. 3705 EnterExpressionEvaluationContext Unevaluated(S, Sema::Unevaluated); 3706 Sema::SFINAETrap SFINAE(S, /*AccessCheckingSFINAE=*/true); 3707 Sema::ContextRAII TUContext(S, S.Context.getTranslationUnitDecl()); 3708 InitializedEntity To(InitializedEntity::InitializeTemporary(Args[0])); 3709 InitializationKind InitKind(InitializationKind::CreateDirect(KWLoc, KWLoc, 3710 RParenLoc)); 3711 InitializationSequence Init(S, To, InitKind, ArgExprs); 3712 if (Init.Failed()) 3713 return false; 3714 3715 ExprResult Result = Init.Perform(S, To, InitKind, ArgExprs); 3716 if (Result.isInvalid() || SFINAE.hasErrorOccurred()) 3717 return false; 3718 3719 if (Kind == clang::TT_IsConstructible) 3720 return true; 3721 3722 if (Kind == clang::TT_IsNothrowConstructible) 3723 return S.canThrow(Result.get()) == CT_Cannot; 3724 3725 if (Kind == clang::TT_IsTriviallyConstructible) { 3726 // Under Objective-C ARC, if the destination has non-trivial Objective-C 3727 // lifetime, this is a non-trivial construction. 3728 if (S.getLangOpts().ObjCAutoRefCount && 3729 hasNontrivialObjCLifetime(Args[0]->getType().getNonReferenceType())) 3730 return false; 3731 3732 // The initialization succeeded; now make sure there are no non-trivial 3733 // calls. 3734 return !Result.get()->hasNonTrivialCall(S.Context); 3735 } 3736 3737 llvm_unreachable("unhandled type trait"); 3738 return false; 3739 } 3740 default: llvm_unreachable("not a TT"); 3741 } 3742 3743 return false; 3744} 3745 3746ExprResult Sema::BuildTypeTrait(TypeTrait Kind, SourceLocation KWLoc, 3747 ArrayRef<TypeSourceInfo *> Args, 3748 SourceLocation RParenLoc) { 3749 QualType ResultType = Context.getLogicalOperationType(); 3750 3751 if (Kind <= UTT_Last && !CheckUnaryTypeTraitTypeCompleteness( 3752 *this, Kind, KWLoc, Args[0]->getType())) 3753 return ExprError(); 3754 3755 bool Dependent = false; 3756 for (unsigned I = 0, N = Args.size(); I != N; ++I) { 3757 if (Args[I]->getType()->isDependentType()) { 3758 Dependent = true; 3759 break; 3760 } 3761 } 3762 3763 bool Result = false; 3764 if (!Dependent) 3765 Result = evaluateTypeTrait(*this, Kind, KWLoc, Args, RParenLoc); 3766 3767 return TypeTraitExpr::Create(Context, ResultType, KWLoc, Kind, Args, 3768 RParenLoc, Result); 3769} 3770 3771ExprResult Sema::ActOnTypeTrait(TypeTrait Kind, SourceLocation KWLoc, 3772 ArrayRef<ParsedType> Args, 3773 SourceLocation RParenLoc) { 3774 SmallVector<TypeSourceInfo *, 4> ConvertedArgs; 3775 ConvertedArgs.reserve(Args.size()); 3776 3777 for (unsigned I = 0, N = Args.size(); I != N; ++I) { 3778 TypeSourceInfo *TInfo; 3779 QualType T = GetTypeFromParser(Args[I], &TInfo); 3780 if (!TInfo) 3781 TInfo = Context.getTrivialTypeSourceInfo(T, KWLoc); 3782 3783 ConvertedArgs.push_back(TInfo); 3784 } 3785 3786 return BuildTypeTrait(Kind, KWLoc, ConvertedArgs, RParenLoc); 3787} 3788 3789static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT, 3790 QualType RhsT, SourceLocation KeyLoc) { 3791 assert(!LhsT->isDependentType() && !RhsT->isDependentType() && 3792 "Cannot evaluate traits of dependent types"); 3793 3794 switch(BTT) { 3795 case BTT_IsBaseOf: { 3796 // C++0x [meta.rel]p2 3797 // Base is a base class of Derived without regard to cv-qualifiers or 3798 // Base and Derived are not unions and name the same class type without 3799 // regard to cv-qualifiers. 3800 3801 const RecordType *lhsRecord = LhsT->getAs<RecordType>(); 3802 if (!lhsRecord) return false; 3803 3804 const RecordType *rhsRecord = RhsT->getAs<RecordType>(); 3805 if (!rhsRecord) return false; 3806 3807 assert(Self.Context.hasSameUnqualifiedType(LhsT, RhsT) 3808 == (lhsRecord == rhsRecord)); 3809 3810 if (lhsRecord == rhsRecord) 3811 return !lhsRecord->getDecl()->isUnion(); 3812 3813 // C++0x [meta.rel]p2: 3814 // If Base and Derived are class types and are different types 3815 // (ignoring possible cv-qualifiers) then Derived shall be a 3816 // complete type. 3817 if (Self.RequireCompleteType(KeyLoc, RhsT, 3818 diag::err_incomplete_type_used_in_type_trait_expr)) 3819 return false; 3820 3821 return cast<CXXRecordDecl>(rhsRecord->getDecl()) 3822 ->isDerivedFrom(cast<CXXRecordDecl>(lhsRecord->getDecl())); 3823 } 3824 case BTT_IsSame: 3825 return Self.Context.hasSameType(LhsT, RhsT); 3826 case BTT_TypeCompatible: 3827 return Self.Context.typesAreCompatible(LhsT.getUnqualifiedType(), 3828 RhsT.getUnqualifiedType()); 3829 case BTT_IsConvertible: 3830 case BTT_IsConvertibleTo: { 3831 // C++0x [meta.rel]p4: 3832 // Given the following function prototype: 3833 // 3834 // template <class T> 3835 // typename add_rvalue_reference<T>::type create(); 3836 // 3837 // the predicate condition for a template specialization 3838 // is_convertible<From, To> shall be satisfied if and only if 3839 // the return expression in the following code would be 3840 // well-formed, including any implicit conversions to the return 3841 // type of the function: 3842 // 3843 // To test() { 3844 // return create<From>(); 3845 // } 3846 // 3847 // Access checking is performed as if in a context unrelated to To and 3848 // From. Only the validity of the immediate context of the expression 3849 // of the return-statement (including conversions to the return type) 3850 // is considered. 3851 // 3852 // We model the initialization as a copy-initialization of a temporary 3853 // of the appropriate type, which for this expression is identical to the 3854 // return statement (since NRVO doesn't apply). 3855 3856 // Functions aren't allowed to return function or array types. 3857 if (RhsT->isFunctionType() || RhsT->isArrayType()) 3858 return false; 3859 3860 // A return statement in a void function must have void type. 3861 if (RhsT->isVoidType()) 3862 return LhsT->isVoidType(); 3863 3864 // A function definition requires a complete, non-abstract return type. 3865 if (Self.RequireCompleteType(KeyLoc, RhsT, 0) || 3866 Self.RequireNonAbstractType(KeyLoc, RhsT, 0)) 3867 return false; 3868 3869 // Compute the result of add_rvalue_reference. 3870 if (LhsT->isObjectType() || LhsT->isFunctionType()) 3871 LhsT = Self.Context.getRValueReferenceType(LhsT); 3872 3873 // Build a fake source and destination for initialization. 3874 InitializedEntity To(InitializedEntity::InitializeTemporary(RhsT)); 3875 OpaqueValueExpr From(KeyLoc, LhsT.getNonLValueExprType(Self.Context), 3876 Expr::getValueKindForType(LhsT)); 3877 Expr *FromPtr = &From; 3878 InitializationKind Kind(InitializationKind::CreateCopy(KeyLoc, 3879 SourceLocation())); 3880 3881 // Perform the initialization in an unevaluated context within a SFINAE 3882 // trap at translation unit scope. 3883 EnterExpressionEvaluationContext Unevaluated(Self, Sema::Unevaluated); 3884 Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true); 3885 Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl()); 3886 InitializationSequence Init(Self, To, Kind, FromPtr); 3887 if (Init.Failed()) 3888 return false; 3889 3890 ExprResult Result = Init.Perform(Self, To, Kind, FromPtr); 3891 return !Result.isInvalid() && !SFINAE.hasErrorOccurred(); 3892 } 3893 3894 case BTT_IsNothrowAssignable: 3895 case BTT_IsTriviallyAssignable: { 3896 // C++11 [meta.unary.prop]p3: 3897 // is_trivially_assignable is defined as: 3898 // is_assignable<T, U>::value is true and the assignment, as defined by 3899 // is_assignable, is known to call no operation that is not trivial 3900 // 3901 // is_assignable is defined as: 3902 // The expression declval<T>() = declval<U>() is well-formed when 3903 // treated as an unevaluated operand (Clause 5). 3904 // 3905 // For both, T and U shall be complete types, (possibly cv-qualified) 3906 // void, or arrays of unknown bound. 3907 if (!LhsT->isVoidType() && !LhsT->isIncompleteArrayType() && 3908 Self.RequireCompleteType(KeyLoc, LhsT, 3909 diag::err_incomplete_type_used_in_type_trait_expr)) 3910 return false; 3911 if (!RhsT->isVoidType() && !RhsT->isIncompleteArrayType() && 3912 Self.RequireCompleteType(KeyLoc, RhsT, 3913 diag::err_incomplete_type_used_in_type_trait_expr)) 3914 return false; 3915 3916 // cv void is never assignable. 3917 if (LhsT->isVoidType() || RhsT->isVoidType()) 3918 return false; 3919 3920 // Build expressions that emulate the effect of declval<T>() and 3921 // declval<U>(). 3922 if (LhsT->isObjectType() || LhsT->isFunctionType()) 3923 LhsT = Self.Context.getRValueReferenceType(LhsT); 3924 if (RhsT->isObjectType() || RhsT->isFunctionType()) 3925 RhsT = Self.Context.getRValueReferenceType(RhsT); 3926 OpaqueValueExpr Lhs(KeyLoc, LhsT.getNonLValueExprType(Self.Context), 3927 Expr::getValueKindForType(LhsT)); 3928 OpaqueValueExpr Rhs(KeyLoc, RhsT.getNonLValueExprType(Self.Context), 3929 Expr::getValueKindForType(RhsT)); 3930 3931 // Attempt the assignment in an unevaluated context within a SFINAE 3932 // trap at translation unit scope. 3933 EnterExpressionEvaluationContext Unevaluated(Self, Sema::Unevaluated); 3934 Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true); 3935 Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl()); 3936 ExprResult Result = Self.BuildBinOp(/*S=*/nullptr, KeyLoc, BO_Assign, &Lhs, 3937 &Rhs); 3938 if (Result.isInvalid() || SFINAE.hasErrorOccurred()) 3939 return false; 3940 3941 if (BTT == BTT_IsNothrowAssignable) 3942 return Self.canThrow(Result.get()) == CT_Cannot; 3943 3944 if (BTT == BTT_IsTriviallyAssignable) { 3945 // Under Objective-C ARC, if the destination has non-trivial Objective-C 3946 // lifetime, this is a non-trivial assignment. 3947 if (Self.getLangOpts().ObjCAutoRefCount && 3948 hasNontrivialObjCLifetime(LhsT.getNonReferenceType())) 3949 return false; 3950 3951 return !Result.get()->hasNonTrivialCall(Self.Context); 3952 } 3953 3954 llvm_unreachable("unhandled type trait"); 3955 return false; 3956 } 3957 default: llvm_unreachable("not a BTT"); 3958 } 3959 llvm_unreachable("Unknown type trait or not implemented"); 3960} 3961 3962ExprResult Sema::ActOnArrayTypeTrait(ArrayTypeTrait ATT, 3963 SourceLocation KWLoc, 3964 ParsedType Ty, 3965 Expr* DimExpr, 3966 SourceLocation RParen) { 3967 TypeSourceInfo *TSInfo; 3968 QualType T = GetTypeFromParser(Ty, &TSInfo); 3969 if (!TSInfo) 3970 TSInfo = Context.getTrivialTypeSourceInfo(T); 3971 3972 return BuildArrayTypeTrait(ATT, KWLoc, TSInfo, DimExpr, RParen); 3973} 3974 3975static uint64_t EvaluateArrayTypeTrait(Sema &Self, ArrayTypeTrait ATT, 3976 QualType T, Expr *DimExpr, 3977 SourceLocation KeyLoc) { 3978 assert(!T->isDependentType() && "Cannot evaluate traits of dependent type"); 3979 3980 switch(ATT) { 3981 case ATT_ArrayRank: 3982 if (T->isArrayType()) { 3983 unsigned Dim = 0; 3984 while (const ArrayType *AT = Self.Context.getAsArrayType(T)) { 3985 ++Dim; 3986 T = AT->getElementType(); 3987 } 3988 return Dim; 3989 } 3990 return 0; 3991 3992 case ATT_ArrayExtent: { 3993 llvm::APSInt Value; 3994 uint64_t Dim; 3995 if (Self.VerifyIntegerConstantExpression(DimExpr, &Value, 3996 diag::err_dimension_expr_not_constant_integer, 3997 false).isInvalid()) 3998 return 0; 3999 if (Value.isSigned() && Value.isNegative()) { 4000 Self.Diag(KeyLoc, diag::err_dimension_expr_not_constant_integer) 4001 << DimExpr->getSourceRange(); 4002 return 0; 4003 } 4004 Dim = Value.getLimitedValue(); 4005 4006 if (T->isArrayType()) { 4007 unsigned D = 0; 4008 bool Matched = false; 4009 while (const ArrayType *AT = Self.Context.getAsArrayType(T)) { 4010 if (Dim == D) { 4011 Matched = true; 4012 break; 4013 } 4014 ++D; 4015 T = AT->getElementType(); 4016 } 4017 4018 if (Matched && T->isArrayType()) { 4019 if (const ConstantArrayType *CAT = Self.Context.getAsConstantArrayType(T)) 4020 return CAT->getSize().getLimitedValue(); 4021 } 4022 } 4023 return 0; 4024 } 4025 } 4026 llvm_unreachable("Unknown type trait or not implemented"); 4027} 4028 4029ExprResult Sema::BuildArrayTypeTrait(ArrayTypeTrait ATT, 4030 SourceLocation KWLoc, 4031 TypeSourceInfo *TSInfo, 4032 Expr* DimExpr, 4033 SourceLocation RParen) { 4034 QualType T = TSInfo->getType(); 4035 4036 // FIXME: This should likely be tracked as an APInt to remove any host 4037 // assumptions about the width of size_t on the target. 4038 uint64_t Value = 0; 4039 if (!T->isDependentType()) 4040 Value = EvaluateArrayTypeTrait(*this, ATT, T, DimExpr, KWLoc); 4041 4042 // While the specification for these traits from the Embarcadero C++ 4043 // compiler's documentation says the return type is 'unsigned int', Clang 4044 // returns 'size_t'. On Windows, the primary platform for the Embarcadero 4045 // compiler, there is no difference. On several other platforms this is an 4046 // important distinction. 4047 return new (Context) ArrayTypeTraitExpr(KWLoc, ATT, TSInfo, Value, DimExpr, 4048 RParen, Context.getSizeType()); 4049} 4050 4051ExprResult Sema::ActOnExpressionTrait(ExpressionTrait ET, 4052 SourceLocation KWLoc, 4053 Expr *Queried, 4054 SourceLocation RParen) { 4055 // If error parsing the expression, ignore. 4056 if (!Queried) 4057 return ExprError(); 4058 4059 ExprResult Result = BuildExpressionTrait(ET, KWLoc, Queried, RParen); 4060 4061 return Result; 4062} 4063 4064static bool EvaluateExpressionTrait(ExpressionTrait ET, Expr *E) { 4065 switch (ET) { 4066 case ET_IsLValueExpr: return E->isLValue(); 4067 case ET_IsRValueExpr: return E->isRValue(); 4068 } 4069 llvm_unreachable("Expression trait not covered by switch"); 4070} 4071 4072ExprResult Sema::BuildExpressionTrait(ExpressionTrait ET, 4073 SourceLocation KWLoc, 4074 Expr *Queried, 4075 SourceLocation RParen) { 4076 if (Queried->isTypeDependent()) { 4077 // Delay type-checking for type-dependent expressions. 4078 } else if (Queried->getType()->isPlaceholderType()) { 4079 ExprResult PE = CheckPlaceholderExpr(Queried); 4080 if (PE.isInvalid()) return ExprError(); 4081 return BuildExpressionTrait(ET, KWLoc, PE.get(), RParen); 4082 } 4083 4084 bool Value = EvaluateExpressionTrait(ET, Queried); 4085 4086 return new (Context) 4087 ExpressionTraitExpr(KWLoc, ET, Queried, Value, RParen, Context.BoolTy); 4088} 4089 4090QualType Sema::CheckPointerToMemberOperands(ExprResult &LHS, ExprResult &RHS, 4091 ExprValueKind &VK, 4092 SourceLocation Loc, 4093 bool isIndirect) { 4094 assert(!LHS.get()->getType()->isPlaceholderType() && 4095 !RHS.get()->getType()->isPlaceholderType() && 4096 "placeholders should have been weeded out by now"); 4097 4098 // The LHS undergoes lvalue conversions if this is ->*. 4099 if (isIndirect) { 4100 LHS = DefaultLvalueConversion(LHS.get()); 4101 if (LHS.isInvalid()) return QualType(); 4102 } 4103 4104 // The RHS always undergoes lvalue conversions. 4105 RHS = DefaultLvalueConversion(RHS.get()); 4106 if (RHS.isInvalid()) return QualType(); 4107 4108 const char *OpSpelling = isIndirect ? "->*" : ".*"; 4109 // C++ 5.5p2 4110 // The binary operator .* [p3: ->*] binds its second operand, which shall 4111 // be of type "pointer to member of T" (where T is a completely-defined 4112 // class type) [...] 4113 QualType RHSType = RHS.get()->getType(); 4114 const MemberPointerType *MemPtr = RHSType->getAs<MemberPointerType>(); 4115 if (!MemPtr) { 4116 Diag(Loc, diag::err_bad_memptr_rhs) 4117 << OpSpelling << RHSType << RHS.get()->getSourceRange(); 4118 return QualType(); 4119 } 4120 4121 QualType Class(MemPtr->getClass(), 0); 4122 4123 // Note: C++ [expr.mptr.oper]p2-3 says that the class type into which the 4124 // member pointer points must be completely-defined. However, there is no 4125 // reason for this semantic distinction, and the rule is not enforced by 4126 // other compilers. Therefore, we do not check this property, as it is 4127 // likely to be considered a defect. 4128 4129 // C++ 5.5p2 4130 // [...] to its first operand, which shall be of class T or of a class of 4131 // which T is an unambiguous and accessible base class. [p3: a pointer to 4132 // such a class] 4133 QualType LHSType = LHS.get()->getType(); 4134 if (isIndirect) { 4135 if (const PointerType *Ptr = LHSType->getAs<PointerType>()) 4136 LHSType = Ptr->getPointeeType(); 4137 else { 4138 Diag(Loc, diag::err_bad_memptr_lhs) 4139 << OpSpelling << 1 << LHSType 4140 << FixItHint::CreateReplacement(SourceRange(Loc), ".*"); 4141 return QualType(); 4142 } 4143 } 4144 4145 if (!Context.hasSameUnqualifiedType(Class, LHSType)) { 4146 // If we want to check the hierarchy, we need a complete type. 4147 if (RequireCompleteType(Loc, LHSType, diag::err_bad_memptr_lhs, 4148 OpSpelling, (int)isIndirect)) { 4149 return QualType(); 4150 } 4151 4152 if (!IsDerivedFrom(LHSType, Class)) { 4153 Diag(Loc, diag::err_bad_memptr_lhs) << OpSpelling 4154 << (int)isIndirect << LHS.get()->getType(); 4155 return QualType(); 4156 } 4157 4158 CXXCastPath BasePath; 4159 if (CheckDerivedToBaseConversion(LHSType, Class, Loc, 4160 SourceRange(LHS.get()->getLocStart(), 4161 RHS.get()->getLocEnd()), 4162 &BasePath)) 4163 return QualType(); 4164 4165 // Cast LHS to type of use. 4166 QualType UseType = isIndirect ? Context.getPointerType(Class) : Class; 4167 ExprValueKind VK = isIndirect ? VK_RValue : LHS.get()->getValueKind(); 4168 LHS = ImpCastExprToType(LHS.get(), UseType, CK_DerivedToBase, VK, 4169 &BasePath); 4170 } 4171 4172 if (isa<CXXScalarValueInitExpr>(RHS.get()->IgnoreParens())) { 4173 // Diagnose use of pointer-to-member type which when used as 4174 // the functional cast in a pointer-to-member expression. 4175 Diag(Loc, diag::err_pointer_to_member_type) << isIndirect; 4176 return QualType(); 4177 } 4178 4179 // C++ 5.5p2 4180 // The result is an object or a function of the type specified by the 4181 // second operand. 4182 // The cv qualifiers are the union of those in the pointer and the left side, 4183 // in accordance with 5.5p5 and 5.2.5. 4184 QualType Result = MemPtr->getPointeeType(); 4185 Result = Context.getCVRQualifiedType(Result, LHSType.getCVRQualifiers()); 4186 4187 // C++0x [expr.mptr.oper]p6: 4188 // In a .* expression whose object expression is an rvalue, the program is 4189 // ill-formed if the second operand is a pointer to member function with 4190 // ref-qualifier &. In a ->* expression or in a .* expression whose object 4191 // expression is an lvalue, the program is ill-formed if the second operand 4192 // is a pointer to member function with ref-qualifier &&. 4193 if (const FunctionProtoType *Proto = Result->getAs<FunctionProtoType>()) { 4194 switch (Proto->getRefQualifier()) { 4195 case RQ_None: 4196 // Do nothing 4197 break; 4198 4199 case RQ_LValue: 4200 if (!isIndirect && !LHS.get()->Classify(Context).isLValue()) 4201 Diag(Loc, diag::err_pointer_to_member_oper_value_classify) 4202 << RHSType << 1 << LHS.get()->getSourceRange(); 4203 break; 4204 4205 case RQ_RValue: 4206 if (isIndirect || !LHS.get()->Classify(Context).isRValue()) 4207 Diag(Loc, diag::err_pointer_to_member_oper_value_classify) 4208 << RHSType << 0 << LHS.get()->getSourceRange(); 4209 break; 4210 } 4211 } 4212 4213 // C++ [expr.mptr.oper]p6: 4214 // The result of a .* expression whose second operand is a pointer 4215 // to a data member is of the same value category as its 4216 // first operand. The result of a .* expression whose second 4217 // operand is a pointer to a member function is a prvalue. The 4218 // result of an ->* expression is an lvalue if its second operand 4219 // is a pointer to data member and a prvalue otherwise. 4220 if (Result->isFunctionType()) { 4221 VK = VK_RValue; 4222 return Context.BoundMemberTy; 4223 } else if (isIndirect) { 4224 VK = VK_LValue; 4225 } else { 4226 VK = LHS.get()->getValueKind(); 4227 } 4228 4229 return Result; 4230} 4231 4232/// \brief Try to convert a type to another according to C++0x 5.16p3. 4233/// 4234/// This is part of the parameter validation for the ? operator. If either 4235/// value operand is a class type, the two operands are attempted to be 4236/// converted to each other. This function does the conversion in one direction. 4237/// It returns true if the program is ill-formed and has already been diagnosed 4238/// as such. 4239static bool TryClassUnification(Sema &Self, Expr *From, Expr *To, 4240 SourceLocation QuestionLoc, 4241 bool &HaveConversion, 4242 QualType &ToType) { 4243 HaveConversion = false; 4244 ToType = To->getType(); 4245 4246 InitializationKind Kind = InitializationKind::CreateCopy(To->getLocStart(), 4247 SourceLocation()); 4248 // C++0x 5.16p3 4249 // The process for determining whether an operand expression E1 of type T1 4250 // can be converted to match an operand expression E2 of type T2 is defined 4251 // as follows: 4252 // -- If E2 is an lvalue: 4253 bool ToIsLvalue = To->isLValue(); 4254 if (ToIsLvalue) { 4255 // E1 can be converted to match E2 if E1 can be implicitly converted to 4256 // type "lvalue reference to T2", subject to the constraint that in the 4257 // conversion the reference must bind directly to E1. 4258 QualType T = Self.Context.getLValueReferenceType(ToType); 4259 InitializedEntity Entity = InitializedEntity::InitializeTemporary(T); 4260 4261 InitializationSequence InitSeq(Self, Entity, Kind, From); 4262 if (InitSeq.isDirectReferenceBinding()) { 4263 ToType = T; 4264 HaveConversion = true; 4265 return false; 4266 } 4267 4268 if (InitSeq.isAmbiguous()) 4269 return InitSeq.Diagnose(Self, Entity, Kind, From); 4270 } 4271 4272 // -- If E2 is an rvalue, or if the conversion above cannot be done: 4273 // -- if E1 and E2 have class type, and the underlying class types are 4274 // the same or one is a base class of the other: 4275 QualType FTy = From->getType(); 4276 QualType TTy = To->getType(); 4277 const RecordType *FRec = FTy->getAs<RecordType>(); 4278 const RecordType *TRec = TTy->getAs<RecordType>(); 4279 bool FDerivedFromT = FRec && TRec && FRec != TRec && 4280 Self.IsDerivedFrom(FTy, TTy); 4281 if (FRec && TRec && 4282 (FRec == TRec || FDerivedFromT || Self.IsDerivedFrom(TTy, FTy))) { 4283 // E1 can be converted to match E2 if the class of T2 is the 4284 // same type as, or a base class of, the class of T1, and 4285 // [cv2 > cv1]. 4286 if (FRec == TRec || FDerivedFromT) { 4287 if (TTy.isAtLeastAsQualifiedAs(FTy)) { 4288 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy); 4289 InitializationSequence InitSeq(Self, Entity, Kind, From); 4290 if (InitSeq) { 4291 HaveConversion = true; 4292 return false; 4293 } 4294 4295 if (InitSeq.isAmbiguous()) 4296 return InitSeq.Diagnose(Self, Entity, Kind, From); 4297 } 4298 } 4299 4300 return false; 4301 } 4302 4303 // -- Otherwise: E1 can be converted to match E2 if E1 can be 4304 // implicitly converted to the type that expression E2 would have 4305 // if E2 were converted to an rvalue (or the type it has, if E2 is 4306 // an rvalue). 4307 // 4308 // This actually refers very narrowly to the lvalue-to-rvalue conversion, not 4309 // to the array-to-pointer or function-to-pointer conversions. 4310 if (!TTy->getAs<TagType>()) 4311 TTy = TTy.getUnqualifiedType(); 4312 4313 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy); 4314 InitializationSequence InitSeq(Self, Entity, Kind, From); 4315 HaveConversion = !InitSeq.Failed(); 4316 ToType = TTy; 4317 if (InitSeq.isAmbiguous()) 4318 return InitSeq.Diagnose(Self, Entity, Kind, From); 4319 4320 return false; 4321} 4322 4323/// \brief Try to find a common type for two according to C++0x 5.16p5. 4324/// 4325/// This is part of the parameter validation for the ? operator. If either 4326/// value operand is a class type, overload resolution is used to find a 4327/// conversion to a common type. 4328static bool FindConditionalOverload(Sema &Self, ExprResult &LHS, ExprResult &RHS, 4329 SourceLocation QuestionLoc) { 4330 Expr *Args[2] = { LHS.get(), RHS.get() }; 4331 OverloadCandidateSet CandidateSet(QuestionLoc, 4332 OverloadCandidateSet::CSK_Operator); 4333 Self.AddBuiltinOperatorCandidates(OO_Conditional, QuestionLoc, Args, 4334 CandidateSet); 4335 4336 OverloadCandidateSet::iterator Best; 4337 switch (CandidateSet.BestViableFunction(Self, QuestionLoc, Best)) { 4338 case OR_Success: { 4339 // We found a match. Perform the conversions on the arguments and move on. 4340 ExprResult LHSRes = 4341 Self.PerformImplicitConversion(LHS.get(), Best->BuiltinTypes.ParamTypes[0], 4342 Best->Conversions[0], Sema::AA_Converting); 4343 if (LHSRes.isInvalid()) 4344 break; 4345 LHS = LHSRes; 4346 4347 ExprResult RHSRes = 4348 Self.PerformImplicitConversion(RHS.get(), Best->BuiltinTypes.ParamTypes[1], 4349 Best->Conversions[1], Sema::AA_Converting); 4350 if (RHSRes.isInvalid()) 4351 break; 4352 RHS = RHSRes; 4353 if (Best->Function) 4354 Self.MarkFunctionReferenced(QuestionLoc, Best->Function); 4355 return false; 4356 } 4357 4358 case OR_No_Viable_Function: 4359 4360 // Emit a better diagnostic if one of the expressions is a null pointer 4361 // constant and the other is a pointer type. In this case, the user most 4362 // likely forgot to take the address of the other expression. 4363 if (Self.DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc)) 4364 return true; 4365 4366 Self.Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4367 << LHS.get()->getType() << RHS.get()->getType() 4368 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 4369 return true; 4370 4371 case OR_Ambiguous: 4372 Self.Diag(QuestionLoc, diag::err_conditional_ambiguous_ovl) 4373 << LHS.get()->getType() << RHS.get()->getType() 4374 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 4375 // FIXME: Print the possible common types by printing the return types of 4376 // the viable candidates. 4377 break; 4378 4379 case OR_Deleted: 4380 llvm_unreachable("Conditional operator has only built-in overloads"); 4381 } 4382 return true; 4383} 4384 4385/// \brief Perform an "extended" implicit conversion as returned by 4386/// TryClassUnification. 4387static bool ConvertForConditional(Sema &Self, ExprResult &E, QualType T) { 4388 InitializedEntity Entity = InitializedEntity::InitializeTemporary(T); 4389 InitializationKind Kind = InitializationKind::CreateCopy(E.get()->getLocStart(), 4390 SourceLocation()); 4391 Expr *Arg = E.get(); 4392 InitializationSequence InitSeq(Self, Entity, Kind, Arg); 4393 ExprResult Result = InitSeq.Perform(Self, Entity, Kind, Arg); 4394 if (Result.isInvalid()) 4395 return true; 4396 4397 E = Result; 4398 return false; 4399} 4400 4401/// \brief Check the operands of ?: under C++ semantics. 4402/// 4403/// See C++ [expr.cond]. Note that LHS is never null, even for the GNU x ?: y 4404/// extension. In this case, LHS == Cond. (But they're not aliases.) 4405QualType Sema::CXXCheckConditionalOperands(ExprResult &Cond, ExprResult &LHS, 4406 ExprResult &RHS, ExprValueKind &VK, 4407 ExprObjectKind &OK, 4408 SourceLocation QuestionLoc) { 4409 // FIXME: Handle C99's complex types, vector types, block pointers and Obj-C++ 4410 // interface pointers. 4411 4412 // C++11 [expr.cond]p1 4413 // The first expression is contextually converted to bool. 4414 if (!Cond.get()->isTypeDependent()) { 4415 ExprResult CondRes = CheckCXXBooleanCondition(Cond.get()); 4416 if (CondRes.isInvalid()) 4417 return QualType(); 4418 Cond = CondRes; 4419 } 4420 4421 // Assume r-value. 4422 VK = VK_RValue; 4423 OK = OK_Ordinary; 4424 4425 // Either of the arguments dependent? 4426 if (LHS.get()->isTypeDependent() || RHS.get()->isTypeDependent()) 4427 return Context.DependentTy; 4428 4429 // C++11 [expr.cond]p2 4430 // If either the second or the third operand has type (cv) void, ... 4431 QualType LTy = LHS.get()->getType(); 4432 QualType RTy = RHS.get()->getType(); 4433 bool LVoid = LTy->isVoidType(); 4434 bool RVoid = RTy->isVoidType(); 4435 if (LVoid || RVoid) { 4436 // ... one of the following shall hold: 4437 // -- The second or the third operand (but not both) is a (possibly 4438 // parenthesized) throw-expression; the result is of the type 4439 // and value category of the other. 4440 bool LThrow = isa<CXXThrowExpr>(LHS.get()->IgnoreParenImpCasts()); 4441 bool RThrow = isa<CXXThrowExpr>(RHS.get()->IgnoreParenImpCasts()); 4442 if (LThrow != RThrow) { 4443 Expr *NonThrow = LThrow ? RHS.get() : LHS.get(); 4444 VK = NonThrow->getValueKind(); 4445 // DR (no number yet): the result is a bit-field if the 4446 // non-throw-expression operand is a bit-field. 4447 OK = NonThrow->getObjectKind(); 4448 return NonThrow->getType(); 4449 } 4450 4451 // -- Both the second and third operands have type void; the result is of 4452 // type void and is a prvalue. 4453 if (LVoid && RVoid) 4454 return Context.VoidTy; 4455 4456 // Neither holds, error. 4457 Diag(QuestionLoc, diag::err_conditional_void_nonvoid) 4458 << (LVoid ? RTy : LTy) << (LVoid ? 0 : 1) 4459 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 4460 return QualType(); 4461 } 4462 4463 // Neither is void. 4464 4465 // C++11 [expr.cond]p3 4466 // Otherwise, if the second and third operand have different types, and 4467 // either has (cv) class type [...] an attempt is made to convert each of 4468 // those operands to the type of the other. 4469 if (!Context.hasSameType(LTy, RTy) && 4470 (LTy->isRecordType() || RTy->isRecordType())) { 4471 // These return true if a single direction is already ambiguous. 4472 QualType L2RType, R2LType; 4473 bool HaveL2R, HaveR2L; 4474 if (TryClassUnification(*this, LHS.get(), RHS.get(), QuestionLoc, HaveL2R, L2RType)) 4475 return QualType(); 4476 if (TryClassUnification(*this, RHS.get(), LHS.get(), QuestionLoc, HaveR2L, R2LType)) 4477 return QualType(); 4478 4479 // If both can be converted, [...] the program is ill-formed. 4480 if (HaveL2R && HaveR2L) { 4481 Diag(QuestionLoc, diag::err_conditional_ambiguous) 4482 << LTy << RTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 4483 return QualType(); 4484 } 4485 4486 // If exactly one conversion is possible, that conversion is applied to 4487 // the chosen operand and the converted operands are used in place of the 4488 // original operands for the remainder of this section. 4489 if (HaveL2R) { 4490 if (ConvertForConditional(*this, LHS, L2RType) || LHS.isInvalid()) 4491 return QualType(); 4492 LTy = LHS.get()->getType(); 4493 } else if (HaveR2L) { 4494 if (ConvertForConditional(*this, RHS, R2LType) || RHS.isInvalid()) 4495 return QualType(); 4496 RTy = RHS.get()->getType(); 4497 } 4498 } 4499 4500 // C++11 [expr.cond]p3 4501 // if both are glvalues of the same value category and the same type except 4502 // for cv-qualification, an attempt is made to convert each of those 4503 // operands to the type of the other. 4504 ExprValueKind LVK = LHS.get()->getValueKind(); 4505 ExprValueKind RVK = RHS.get()->getValueKind(); 4506 if (!Context.hasSameType(LTy, RTy) && 4507 Context.hasSameUnqualifiedType(LTy, RTy) && 4508 LVK == RVK && LVK != VK_RValue) { 4509 // Since the unqualified types are reference-related and we require the 4510 // result to be as if a reference bound directly, the only conversion 4511 // we can perform is to add cv-qualifiers. 4512 Qualifiers LCVR = Qualifiers::fromCVRMask(LTy.getCVRQualifiers()); 4513 Qualifiers RCVR = Qualifiers::fromCVRMask(RTy.getCVRQualifiers()); 4514 if (RCVR.isStrictSupersetOf(LCVR)) { 4515 LHS = ImpCastExprToType(LHS.get(), RTy, CK_NoOp, LVK); 4516 LTy = LHS.get()->getType(); 4517 } 4518 else if (LCVR.isStrictSupersetOf(RCVR)) { 4519 RHS = ImpCastExprToType(RHS.get(), LTy, CK_NoOp, RVK); 4520 RTy = RHS.get()->getType(); 4521 } 4522 } 4523 4524 // C++11 [expr.cond]p4 4525 // If the second and third operands are glvalues of the same value 4526 // category and have the same type, the result is of that type and 4527 // value category and it is a bit-field if the second or the third 4528 // operand is a bit-field, or if both are bit-fields. 4529 // We only extend this to bitfields, not to the crazy other kinds of 4530 // l-values. 4531 bool Same = Context.hasSameType(LTy, RTy); 4532 if (Same && LVK == RVK && LVK != VK_RValue && 4533 LHS.get()->isOrdinaryOrBitFieldObject() && 4534 RHS.get()->isOrdinaryOrBitFieldObject()) { 4535 VK = LHS.get()->getValueKind(); 4536 if (LHS.get()->getObjectKind() == OK_BitField || 4537 RHS.get()->getObjectKind() == OK_BitField) 4538 OK = OK_BitField; 4539 return LTy; 4540 } 4541 4542 // C++11 [expr.cond]p5 4543 // Otherwise, the result is a prvalue. If the second and third operands 4544 // do not have the same type, and either has (cv) class type, ... 4545 if (!Same && (LTy->isRecordType() || RTy->isRecordType())) { 4546 // ... overload resolution is used to determine the conversions (if any) 4547 // to be applied to the operands. If the overload resolution fails, the 4548 // program is ill-formed. 4549 if (FindConditionalOverload(*this, LHS, RHS, QuestionLoc)) 4550 return QualType(); 4551 } 4552 4553 // C++11 [expr.cond]p6 4554 // Lvalue-to-rvalue, array-to-pointer, and function-to-pointer standard 4555 // conversions are performed on the second and third operands. 4556 LHS = DefaultFunctionArrayLvalueConversion(LHS.get()); 4557 RHS = DefaultFunctionArrayLvalueConversion(RHS.get()); 4558 if (LHS.isInvalid() || RHS.isInvalid()) 4559 return QualType(); 4560 LTy = LHS.get()->getType(); 4561 RTy = RHS.get()->getType(); 4562 4563 // After those conversions, one of the following shall hold: 4564 // -- The second and third operands have the same type; the result 4565 // is of that type. If the operands have class type, the result 4566 // is a prvalue temporary of the result type, which is 4567 // copy-initialized from either the second operand or the third 4568 // operand depending on the value of the first operand. 4569 if (Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy)) { 4570 if (LTy->isRecordType()) { 4571 // The operands have class type. Make a temporary copy. 4572 if (RequireNonAbstractType(QuestionLoc, LTy, 4573 diag::err_allocation_of_abstract_type)) 4574 return QualType(); 4575 InitializedEntity Entity = InitializedEntity::InitializeTemporary(LTy); 4576 4577 ExprResult LHSCopy = PerformCopyInitialization(Entity, 4578 SourceLocation(), 4579 LHS); 4580 if (LHSCopy.isInvalid()) 4581 return QualType(); 4582 4583 ExprResult RHSCopy = PerformCopyInitialization(Entity, 4584 SourceLocation(), 4585 RHS); 4586 if (RHSCopy.isInvalid()) 4587 return QualType(); 4588 4589 LHS = LHSCopy; 4590 RHS = RHSCopy; 4591 } 4592 4593 return LTy; 4594 } 4595 4596 // Extension: conditional operator involving vector types. 4597 if (LTy->isVectorType() || RTy->isVectorType()) 4598 return CheckVectorOperands(LHS, RHS, QuestionLoc, /*isCompAssign*/false); 4599 4600 // -- The second and third operands have arithmetic or enumeration type; 4601 // the usual arithmetic conversions are performed to bring them to a 4602 // common type, and the result is of that type. 4603 if (LTy->isArithmeticType() && RTy->isArithmeticType()) { 4604 QualType ResTy = UsualArithmeticConversions(LHS, RHS); 4605 if (LHS.isInvalid() || RHS.isInvalid()) 4606 return QualType(); 4607 4608 LHS = ImpCastExprToType(LHS.get(), ResTy, PrepareScalarCast(LHS, ResTy)); 4609 RHS = ImpCastExprToType(RHS.get(), ResTy, PrepareScalarCast(RHS, ResTy)); 4610 4611 return ResTy; 4612 } 4613 4614 // -- The second and third operands have pointer type, or one has pointer 4615 // type and the other is a null pointer constant, or both are null 4616 // pointer constants, at least one of which is non-integral; pointer 4617 // conversions and qualification conversions are performed to bring them 4618 // to their composite pointer type. The result is of the composite 4619 // pointer type. 4620 // -- The second and third operands have pointer to member type, or one has 4621 // pointer to member type and the other is a null pointer constant; 4622 // pointer to member conversions and qualification conversions are 4623 // performed to bring them to a common type, whose cv-qualification 4624 // shall match the cv-qualification of either the second or the third 4625 // operand. The result is of the common type. 4626 bool NonStandardCompositeType = false; 4627 QualType Composite = FindCompositePointerType(QuestionLoc, LHS, RHS, 4628 isSFINAEContext() ? nullptr 4629 : &NonStandardCompositeType); 4630 if (!Composite.isNull()) { 4631 if (NonStandardCompositeType) 4632 Diag(QuestionLoc, 4633 diag::ext_typecheck_cond_incompatible_operands_nonstandard) 4634 << LTy << RTy << Composite 4635 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 4636 4637 return Composite; 4638 } 4639 4640 // Similarly, attempt to find composite type of two objective-c pointers. 4641 Composite = FindCompositeObjCPointerType(LHS, RHS, QuestionLoc); 4642 if (!Composite.isNull()) 4643 return Composite; 4644 4645 // Check if we are using a null with a non-pointer type. 4646 if (DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc)) 4647 return QualType(); 4648 4649 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4650 << LHS.get()->getType() << RHS.get()->getType() 4651 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 4652 return QualType(); 4653} 4654 4655/// \brief Find a merged pointer type and convert the two expressions to it. 4656/// 4657/// This finds the composite pointer type (or member pointer type) for @p E1 4658/// and @p E2 according to C++11 5.9p2. It converts both expressions to this 4659/// type and returns it. 4660/// It does not emit diagnostics. 4661/// 4662/// \param Loc The location of the operator requiring these two expressions to 4663/// be converted to the composite pointer type. 4664/// 4665/// If \p NonStandardCompositeType is non-NULL, then we are permitted to find 4666/// a non-standard (but still sane) composite type to which both expressions 4667/// can be converted. When such a type is chosen, \c *NonStandardCompositeType 4668/// will be set true. 4669QualType Sema::FindCompositePointerType(SourceLocation Loc, 4670 Expr *&E1, Expr *&E2, 4671 bool *NonStandardCompositeType) { 4672 if (NonStandardCompositeType) 4673 *NonStandardCompositeType = false; 4674 4675 assert(getLangOpts().CPlusPlus && "This function assumes C++"); 4676 QualType T1 = E1->getType(), T2 = E2->getType(); 4677 4678 // C++11 5.9p2 4679 // Pointer conversions and qualification conversions are performed on 4680 // pointer operands to bring them to their composite pointer type. If 4681 // one operand is a null pointer constant, the composite pointer type is 4682 // std::nullptr_t if the other operand is also a null pointer constant or, 4683 // if the other operand is a pointer, the type of the other operand. 4684 if (!T1->isAnyPointerType() && !T1->isMemberPointerType() && 4685 !T2->isAnyPointerType() && !T2->isMemberPointerType()) { 4686 if (T1->isNullPtrType() && 4687 E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4688 E2 = ImpCastExprToType(E2, T1, CK_NullToPointer).get(); 4689 return T1; 4690 } 4691 if (T2->isNullPtrType() && 4692 E1->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4693 E1 = ImpCastExprToType(E1, T2, CK_NullToPointer).get(); 4694 return T2; 4695 } 4696 return QualType(); 4697 } 4698 4699 if (E1->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4700 if (T2->isMemberPointerType()) 4701 E1 = ImpCastExprToType(E1, T2, CK_NullToMemberPointer).get(); 4702 else 4703 E1 = ImpCastExprToType(E1, T2, CK_NullToPointer).get(); 4704 return T2; 4705 } 4706 if (E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4707 if (T1->isMemberPointerType()) 4708 E2 = ImpCastExprToType(E2, T1, CK_NullToMemberPointer).get(); 4709 else 4710 E2 = ImpCastExprToType(E2, T1, CK_NullToPointer).get(); 4711 return T1; 4712 } 4713 4714 // Now both have to be pointers or member pointers. 4715 if ((!T1->isPointerType() && !T1->isMemberPointerType()) || 4716 (!T2->isPointerType() && !T2->isMemberPointerType())) 4717 return QualType(); 4718 4719 // Otherwise, of one of the operands has type "pointer to cv1 void," then 4720 // the other has type "pointer to cv2 T" and the composite pointer type is 4721 // "pointer to cv12 void," where cv12 is the union of cv1 and cv2. 4722 // Otherwise, the composite pointer type is a pointer type similar to the 4723 // type of one of the operands, with a cv-qualification signature that is 4724 // the union of the cv-qualification signatures of the operand types. 4725 // In practice, the first part here is redundant; it's subsumed by the second. 4726 // What we do here is, we build the two possible composite types, and try the 4727 // conversions in both directions. If only one works, or if the two composite 4728 // types are the same, we have succeeded. 4729 // FIXME: extended qualifiers? 4730 typedef SmallVector<unsigned, 4> QualifierVector; 4731 QualifierVector QualifierUnion; 4732 typedef SmallVector<std::pair<const Type *, const Type *>, 4> 4733 ContainingClassVector; 4734 ContainingClassVector MemberOfClass; 4735 QualType Composite1 = Context.getCanonicalType(T1), 4736 Composite2 = Context.getCanonicalType(T2); 4737 unsigned NeedConstBefore = 0; 4738 do { 4739 const PointerType *Ptr1, *Ptr2; 4740 if ((Ptr1 = Composite1->getAs<PointerType>()) && 4741 (Ptr2 = Composite2->getAs<PointerType>())) { 4742 Composite1 = Ptr1->getPointeeType(); 4743 Composite2 = Ptr2->getPointeeType(); 4744 4745 // If we're allowed to create a non-standard composite type, keep track 4746 // of where we need to fill in additional 'const' qualifiers. 4747 if (NonStandardCompositeType && 4748 Composite1.getCVRQualifiers() != Composite2.getCVRQualifiers()) 4749 NeedConstBefore = QualifierUnion.size(); 4750 4751 QualifierUnion.push_back( 4752 Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers()); 4753 MemberOfClass.push_back(std::make_pair(nullptr, nullptr)); 4754 continue; 4755 } 4756 4757 const MemberPointerType *MemPtr1, *MemPtr2; 4758 if ((MemPtr1 = Composite1->getAs<MemberPointerType>()) && 4759 (MemPtr2 = Composite2->getAs<MemberPointerType>())) { 4760 Composite1 = MemPtr1->getPointeeType(); 4761 Composite2 = MemPtr2->getPointeeType(); 4762 4763 // If we're allowed to create a non-standard composite type, keep track 4764 // of where we need to fill in additional 'const' qualifiers. 4765 if (NonStandardCompositeType && 4766 Composite1.getCVRQualifiers() != Composite2.getCVRQualifiers()) 4767 NeedConstBefore = QualifierUnion.size(); 4768 4769 QualifierUnion.push_back( 4770 Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers()); 4771 MemberOfClass.push_back(std::make_pair(MemPtr1->getClass(), 4772 MemPtr2->getClass())); 4773 continue; 4774 } 4775 4776 // FIXME: block pointer types? 4777 4778 // Cannot unwrap any more types. 4779 break; 4780 } while (true); 4781 4782 if (NeedConstBefore && NonStandardCompositeType) { 4783 // Extension: Add 'const' to qualifiers that come before the first qualifier 4784 // mismatch, so that our (non-standard!) composite type meets the 4785 // requirements of C++ [conv.qual]p4 bullet 3. 4786 for (unsigned I = 0; I != NeedConstBefore; ++I) { 4787 if ((QualifierUnion[I] & Qualifiers::Const) == 0) { 4788 QualifierUnion[I] = QualifierUnion[I] | Qualifiers::Const; 4789 *NonStandardCompositeType = true; 4790 } 4791 } 4792 } 4793 4794 // Rewrap the composites as pointers or member pointers with the union CVRs. 4795 ContainingClassVector::reverse_iterator MOC 4796 = MemberOfClass.rbegin(); 4797 for (QualifierVector::reverse_iterator 4798 I = QualifierUnion.rbegin(), 4799 E = QualifierUnion.rend(); 4800 I != E; (void)++I, ++MOC) { 4801 Qualifiers Quals = Qualifiers::fromCVRMask(*I); 4802 if (MOC->first && MOC->second) { 4803 // Rebuild member pointer type 4804 Composite1 = Context.getMemberPointerType( 4805 Context.getQualifiedType(Composite1, Quals), 4806 MOC->first); 4807 Composite2 = Context.getMemberPointerType( 4808 Context.getQualifiedType(Composite2, Quals), 4809 MOC->second); 4810 } else { 4811 // Rebuild pointer type 4812 Composite1 4813 = Context.getPointerType(Context.getQualifiedType(Composite1, Quals)); 4814 Composite2 4815 = Context.getPointerType(Context.getQualifiedType(Composite2, Quals)); 4816 } 4817 } 4818 4819 // Try to convert to the first composite pointer type. 4820 InitializedEntity Entity1 4821 = InitializedEntity::InitializeTemporary(Composite1); 4822 InitializationKind Kind 4823 = InitializationKind::CreateCopy(Loc, SourceLocation()); 4824 InitializationSequence E1ToC1(*this, Entity1, Kind, E1); 4825 InitializationSequence E2ToC1(*this, Entity1, Kind, E2); 4826 4827 if (E1ToC1 && E2ToC1) { 4828 // Conversion to Composite1 is viable. 4829 if (!Context.hasSameType(Composite1, Composite2)) { 4830 // Composite2 is a different type from Composite1. Check whether 4831 // Composite2 is also viable. 4832 InitializedEntity Entity2 4833 = InitializedEntity::InitializeTemporary(Composite2); 4834 InitializationSequence E1ToC2(*this, Entity2, Kind, E1); 4835 InitializationSequence E2ToC2(*this, Entity2, Kind, E2); 4836 if (E1ToC2 && E2ToC2) { 4837 // Both Composite1 and Composite2 are viable and are different; 4838 // this is an ambiguity. 4839 return QualType(); 4840 } 4841 } 4842 4843 // Convert E1 to Composite1 4844 ExprResult E1Result 4845 = E1ToC1.Perform(*this, Entity1, Kind, E1); 4846 if (E1Result.isInvalid()) 4847 return QualType(); 4848 E1 = E1Result.getAs<Expr>(); 4849 4850 // Convert E2 to Composite1 4851 ExprResult E2Result 4852 = E2ToC1.Perform(*this, Entity1, Kind, E2); 4853 if (E2Result.isInvalid()) 4854 return QualType(); 4855 E2 = E2Result.getAs<Expr>(); 4856 4857 return Composite1; 4858 } 4859 4860 // Check whether Composite2 is viable. 4861 InitializedEntity Entity2 4862 = InitializedEntity::InitializeTemporary(Composite2); 4863 InitializationSequence E1ToC2(*this, Entity2, Kind, E1); 4864 InitializationSequence E2ToC2(*this, Entity2, Kind, E2); 4865 if (!E1ToC2 || !E2ToC2) 4866 return QualType(); 4867 4868 // Convert E1 to Composite2 4869 ExprResult E1Result 4870 = E1ToC2.Perform(*this, Entity2, Kind, E1); 4871 if (E1Result.isInvalid()) 4872 return QualType(); 4873 E1 = E1Result.getAs<Expr>(); 4874 4875 // Convert E2 to Composite2 4876 ExprResult E2Result 4877 = E2ToC2.Perform(*this, Entity2, Kind, E2); 4878 if (E2Result.isInvalid()) 4879 return QualType(); 4880 E2 = E2Result.getAs<Expr>(); 4881 4882 return Composite2; 4883} 4884 4885ExprResult Sema::MaybeBindToTemporary(Expr *E) { 4886 if (!E) 4887 return ExprError(); 4888 4889 assert(!isa<CXXBindTemporaryExpr>(E) && "Double-bound temporary?"); 4890 4891 // If the result is a glvalue, we shouldn't bind it. 4892 if (!E->isRValue()) 4893 return E; 4894 4895 // In ARC, calls that return a retainable type can return retained, 4896 // in which case we have to insert a consuming cast. 4897 if (getLangOpts().ObjCAutoRefCount && 4898 E->getType()->isObjCRetainableType()) { 4899 4900 bool ReturnsRetained; 4901 4902 // For actual calls, we compute this by examining the type of the 4903 // called value. 4904 if (CallExpr *Call = dyn_cast<CallExpr>(E)) { 4905 Expr *Callee = Call->getCallee()->IgnoreParens(); 4906 QualType T = Callee->getType(); 4907 4908 if (T == Context.BoundMemberTy) { 4909 // Handle pointer-to-members. 4910 if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(Callee)) 4911 T = BinOp->getRHS()->getType(); 4912 else if (MemberExpr *Mem = dyn_cast<MemberExpr>(Callee)) 4913 T = Mem->getMemberDecl()->getType(); 4914 } 4915 4916 if (const PointerType *Ptr = T->getAs<PointerType>()) 4917 T = Ptr->getPointeeType(); 4918 else if (const BlockPointerType *Ptr = T->getAs<BlockPointerType>()) 4919 T = Ptr->getPointeeType(); 4920 else if (const MemberPointerType *MemPtr = T->getAs<MemberPointerType>()) 4921 T = MemPtr->getPointeeType(); 4922 4923 const FunctionType *FTy = T->getAs<FunctionType>(); 4924 assert(FTy && "call to value not of function type?"); 4925 ReturnsRetained = FTy->getExtInfo().getProducesResult(); 4926 4927 // ActOnStmtExpr arranges things so that StmtExprs of retainable 4928 // type always produce a +1 object. 4929 } else if (isa<StmtExpr>(E)) { 4930 ReturnsRetained = true; 4931 4932 // We hit this case with the lambda conversion-to-block optimization; 4933 // we don't want any extra casts here. 4934 } else if (isa<CastExpr>(E) && 4935 isa<BlockExpr>(cast<CastExpr>(E)->getSubExpr())) { 4936 return E; 4937 4938 // For message sends and property references, we try to find an 4939 // actual method. FIXME: we should infer retention by selector in 4940 // cases where we don't have an actual method. 4941 } else { 4942 ObjCMethodDecl *D = nullptr; 4943 if (ObjCMessageExpr *Send = dyn_cast<ObjCMessageExpr>(E)) { 4944 D = Send->getMethodDecl(); 4945 } else if (ObjCBoxedExpr *BoxedExpr = dyn_cast<ObjCBoxedExpr>(E)) { 4946 D = BoxedExpr->getBoxingMethod(); 4947 } else if (ObjCArrayLiteral *ArrayLit = dyn_cast<ObjCArrayLiteral>(E)) { 4948 D = ArrayLit->getArrayWithObjectsMethod(); 4949 } else if (ObjCDictionaryLiteral *DictLit 4950 = dyn_cast<ObjCDictionaryLiteral>(E)) { 4951 D = DictLit->getDictWithObjectsMethod(); 4952 } 4953 4954 ReturnsRetained = (D && D->hasAttr<NSReturnsRetainedAttr>()); 4955 4956 // Don't do reclaims on performSelector calls; despite their 4957 // return type, the invoked method doesn't necessarily actually 4958 // return an object. 4959 if (!ReturnsRetained && 4960 D && D->getMethodFamily() == OMF_performSelector) 4961 return E; 4962 } 4963 4964 // Don't reclaim an object of Class type. 4965 if (!ReturnsRetained && E->getType()->isObjCARCImplicitlyUnretainedType()) 4966 return E; 4967 4968 ExprNeedsCleanups = true; 4969 4970 CastKind ck = (ReturnsRetained ? CK_ARCConsumeObject 4971 : CK_ARCReclaimReturnedObject); 4972 return ImplicitCastExpr::Create(Context, E->getType(), ck, E, nullptr, 4973 VK_RValue); 4974 } 4975 4976 if (!getLangOpts().CPlusPlus) 4977 return E; 4978 4979 // Search for the base element type (cf. ASTContext::getBaseElementType) with 4980 // a fast path for the common case that the type is directly a RecordType. 4981 const Type *T = Context.getCanonicalType(E->getType().getTypePtr()); 4982 const RecordType *RT = nullptr; 4983 while (!RT) { 4984 switch (T->getTypeClass()) { 4985 case Type::Record: 4986 RT = cast<RecordType>(T); 4987 break; 4988 case Type::ConstantArray: 4989 case Type::IncompleteArray: 4990 case Type::VariableArray: 4991 case Type::DependentSizedArray: 4992 T = cast<ArrayType>(T)->getElementType().getTypePtr(); 4993 break; 4994 default: 4995 return E; 4996 } 4997 } 4998 4999 // That should be enough to guarantee that this type is complete, if we're 5000 // not processing a decltype expression. 5001 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 5002 if (RD->isInvalidDecl() || RD->isDependentContext()) 5003 return E; 5004 5005 bool IsDecltype = ExprEvalContexts.back().IsDecltype; 5006 CXXDestructorDecl *Destructor = IsDecltype ? nullptr : LookupDestructor(RD); 5007 5008 if (Destructor) { 5009 MarkFunctionReferenced(E->getExprLoc(), Destructor); 5010 CheckDestructorAccess(E->getExprLoc(), Destructor, 5011 PDiag(diag::err_access_dtor_temp) 5012 << E->getType()); 5013 if (DiagnoseUseOfDecl(Destructor, E->getExprLoc())) 5014 return ExprError(); 5015 5016 // If destructor is trivial, we can avoid the extra copy. 5017 if (Destructor->isTrivial()) 5018 return E; 5019 5020 // We need a cleanup, but we don't need to remember the temporary. 5021 ExprNeedsCleanups = true; 5022 } 5023 5024 CXXTemporary *Temp = CXXTemporary::Create(Context, Destructor); 5025 CXXBindTemporaryExpr *Bind = CXXBindTemporaryExpr::Create(Context, Temp, E); 5026 5027 if (IsDecltype) 5028 ExprEvalContexts.back().DelayedDecltypeBinds.push_back(Bind); 5029 5030 return Bind; 5031} 5032 5033ExprResult 5034Sema::MaybeCreateExprWithCleanups(ExprResult SubExpr) { 5035 if (SubExpr.isInvalid()) 5036 return ExprError(); 5037 5038 return MaybeCreateExprWithCleanups(SubExpr.get()); 5039} 5040 5041Expr *Sema::MaybeCreateExprWithCleanups(Expr *SubExpr) { 5042 assert(SubExpr && "subexpression can't be null!"); 5043 5044 CleanupVarDeclMarking(); 5045 5046 unsigned FirstCleanup = ExprEvalContexts.back().NumCleanupObjects; 5047 assert(ExprCleanupObjects.size() >= FirstCleanup); 5048 assert(ExprNeedsCleanups || ExprCleanupObjects.size() == FirstCleanup); 5049 if (!ExprNeedsCleanups) 5050 return SubExpr; 5051 5052 auto Cleanups = llvm::makeArrayRef(ExprCleanupObjects.begin() + FirstCleanup, 5053 ExprCleanupObjects.size() - FirstCleanup); 5054 5055 Expr *E = ExprWithCleanups::Create(Context, SubExpr, Cleanups); 5056 DiscardCleanupsInEvaluationContext(); 5057 5058 return E; 5059} 5060 5061Stmt *Sema::MaybeCreateStmtWithCleanups(Stmt *SubStmt) { 5062 assert(SubStmt && "sub-statement can't be null!"); 5063 5064 CleanupVarDeclMarking(); 5065 5066 if (!ExprNeedsCleanups) 5067 return SubStmt; 5068 5069 // FIXME: In order to attach the temporaries, wrap the statement into 5070 // a StmtExpr; currently this is only used for asm statements. 5071 // This is hacky, either create a new CXXStmtWithTemporaries statement or 5072 // a new AsmStmtWithTemporaries. 5073 CompoundStmt *CompStmt = new (Context) CompoundStmt(Context, SubStmt, 5074 SourceLocation(), 5075 SourceLocation()); 5076 Expr *E = new (Context) StmtExpr(CompStmt, Context.VoidTy, SourceLocation(), 5077 SourceLocation()); 5078 return MaybeCreateExprWithCleanups(E); 5079} 5080 5081/// Process the expression contained within a decltype. For such expressions, 5082/// certain semantic checks on temporaries are delayed until this point, and 5083/// are omitted for the 'topmost' call in the decltype expression. If the 5084/// topmost call bound a temporary, strip that temporary off the expression. 5085ExprResult Sema::ActOnDecltypeExpression(Expr *E) { 5086 assert(ExprEvalContexts.back().IsDecltype && "not in a decltype expression"); 5087 5088 // C++11 [expr.call]p11: 5089 // If a function call is a prvalue of object type, 5090 // -- if the function call is either 5091 // -- the operand of a decltype-specifier, or 5092 // -- the right operand of a comma operator that is the operand of a 5093 // decltype-specifier, 5094 // a temporary object is not introduced for the prvalue. 5095 5096 // Recursively rebuild ParenExprs and comma expressions to strip out the 5097 // outermost CXXBindTemporaryExpr, if any. 5098 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 5099 ExprResult SubExpr = ActOnDecltypeExpression(PE->getSubExpr()); 5100 if (SubExpr.isInvalid()) 5101 return ExprError(); 5102 if (SubExpr.get() == PE->getSubExpr()) 5103 return E; 5104 return ActOnParenExpr(PE->getLParen(), PE->getRParen(), SubExpr.get()); 5105 } 5106 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) { 5107 if (BO->getOpcode() == BO_Comma) { 5108 ExprResult RHS = ActOnDecltypeExpression(BO->getRHS()); 5109 if (RHS.isInvalid()) 5110 return ExprError(); 5111 if (RHS.get() == BO->getRHS()) 5112 return E; 5113 return new (Context) BinaryOperator( 5114 BO->getLHS(), RHS.get(), BO_Comma, BO->getType(), BO->getValueKind(), 5115 BO->getObjectKind(), BO->getOperatorLoc(), BO->isFPContractable()); 5116 } 5117 } 5118 5119 CXXBindTemporaryExpr *TopBind = dyn_cast<CXXBindTemporaryExpr>(E); 5120 CallExpr *TopCall = TopBind ? dyn_cast<CallExpr>(TopBind->getSubExpr()) 5121 : nullptr; 5122 if (TopCall) 5123 E = TopCall; 5124 else 5125 TopBind = nullptr; 5126 5127 // Disable the special decltype handling now. 5128 ExprEvalContexts.back().IsDecltype = false; 5129 5130 // In MS mode, don't perform any extra checking of call return types within a 5131 // decltype expression. 5132 if (getLangOpts().MSVCCompat) 5133 return E; 5134 5135 // Perform the semantic checks we delayed until this point. 5136 for (unsigned I = 0, N = ExprEvalContexts.back().DelayedDecltypeCalls.size(); 5137 I != N; ++I) { 5138 CallExpr *Call = ExprEvalContexts.back().DelayedDecltypeCalls[I]; 5139 if (Call == TopCall) 5140 continue; 5141 5142 if (CheckCallReturnType(Call->getCallReturnType(), 5143 Call->getLocStart(), 5144 Call, Call->getDirectCallee())) 5145 return ExprError(); 5146 } 5147 5148 // Now all relevant types are complete, check the destructors are accessible 5149 // and non-deleted, and annotate them on the temporaries. 5150 for (unsigned I = 0, N = ExprEvalContexts.back().DelayedDecltypeBinds.size(); 5151 I != N; ++I) { 5152 CXXBindTemporaryExpr *Bind = 5153 ExprEvalContexts.back().DelayedDecltypeBinds[I]; 5154 if (Bind == TopBind) 5155 continue; 5156 5157 CXXTemporary *Temp = Bind->getTemporary(); 5158 5159 CXXRecordDecl *RD = 5160 Bind->getType()->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); 5161 CXXDestructorDecl *Destructor = LookupDestructor(RD); 5162 Temp->setDestructor(Destructor); 5163 5164 MarkFunctionReferenced(Bind->getExprLoc(), Destructor); 5165 CheckDestructorAccess(Bind->getExprLoc(), Destructor, 5166 PDiag(diag::err_access_dtor_temp) 5167 << Bind->getType()); 5168 if (DiagnoseUseOfDecl(Destructor, Bind->getExprLoc())) 5169 return ExprError(); 5170 5171 // We need a cleanup, but we don't need to remember the temporary. 5172 ExprNeedsCleanups = true; 5173 } 5174 5175 // Possibly strip off the top CXXBindTemporaryExpr. 5176 return E; 5177} 5178 5179/// Note a set of 'operator->' functions that were used for a member access. 5180static void noteOperatorArrows(Sema &S, 5181 ArrayRef<FunctionDecl *> OperatorArrows) { 5182 unsigned SkipStart = OperatorArrows.size(), SkipCount = 0; 5183 // FIXME: Make this configurable? 5184 unsigned Limit = 9; 5185 if (OperatorArrows.size() > Limit) { 5186 // Produce Limit-1 normal notes and one 'skipping' note. 5187 SkipStart = (Limit - 1) / 2 + (Limit - 1) % 2; 5188 SkipCount = OperatorArrows.size() - (Limit - 1); 5189 } 5190 5191 for (unsigned I = 0; I < OperatorArrows.size(); /**/) { 5192 if (I == SkipStart) { 5193 S.Diag(OperatorArrows[I]->getLocation(), 5194 diag::note_operator_arrows_suppressed) 5195 << SkipCount; 5196 I += SkipCount; 5197 } else { 5198 S.Diag(OperatorArrows[I]->getLocation(), diag::note_operator_arrow_here) 5199 << OperatorArrows[I]->getCallResultType(); 5200 ++I; 5201 } 5202 } 5203} 5204 5205ExprResult 5206Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base, SourceLocation OpLoc, 5207 tok::TokenKind OpKind, ParsedType &ObjectType, 5208 bool &MayBePseudoDestructor) { 5209 // Since this might be a postfix expression, get rid of ParenListExprs. 5210 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base); 5211 if (Result.isInvalid()) return ExprError(); 5212 Base = Result.get(); 5213 5214 Result = CheckPlaceholderExpr(Base); 5215 if (Result.isInvalid()) return ExprError(); 5216 Base = Result.get(); 5217 5218 QualType BaseType = Base->getType(); 5219 MayBePseudoDestructor = false; 5220 if (BaseType->isDependentType()) { 5221 // If we have a pointer to a dependent type and are using the -> operator, 5222 // the object type is the type that the pointer points to. We might still 5223 // have enough information about that type to do something useful. 5224 if (OpKind == tok::arrow) 5225 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) 5226 BaseType = Ptr->getPointeeType(); 5227 5228 ObjectType = ParsedType::make(BaseType); 5229 MayBePseudoDestructor = true; 5230 return Base; 5231 } 5232 5233 // C++ [over.match.oper]p8: 5234 // [...] When operator->returns, the operator-> is applied to the value 5235 // returned, with the original second operand. 5236 if (OpKind == tok::arrow) { 5237 QualType StartingType = BaseType; 5238 bool NoArrowOperatorFound = false; 5239 bool FirstIteration = true; 5240 FunctionDecl *CurFD = dyn_cast<FunctionDecl>(CurContext); 5241 // The set of types we've considered so far. 5242 llvm::SmallPtrSet<CanQualType,8> CTypes; 5243 SmallVector<FunctionDecl*, 8> OperatorArrows; 5244 CTypes.insert(Context.getCanonicalType(BaseType)); 5245 5246 while (BaseType->isRecordType()) { 5247 if (OperatorArrows.size() >= getLangOpts().ArrowDepth) { 5248 Diag(OpLoc, diag::err_operator_arrow_depth_exceeded) 5249 << StartingType << getLangOpts().ArrowDepth << Base->getSourceRange(); 5250 noteOperatorArrows(*this, OperatorArrows); 5251 Diag(OpLoc, diag::note_operator_arrow_depth) 5252 << getLangOpts().ArrowDepth; 5253 return ExprError(); 5254 } 5255 5256 Result = BuildOverloadedArrowExpr( 5257 S, Base, OpLoc, 5258 // When in a template specialization and on the first loop iteration, 5259 // potentially give the default diagnostic (with the fixit in a 5260 // separate note) instead of having the error reported back to here 5261 // and giving a diagnostic with a fixit attached to the error itself. 5262 (FirstIteration && CurFD && CurFD->isFunctionTemplateSpecialization()) 5263 ? nullptr 5264 : &NoArrowOperatorFound); 5265 if (Result.isInvalid()) { 5266 if (NoArrowOperatorFound) { 5267 if (FirstIteration) { 5268 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 5269 << BaseType << 1 << Base->getSourceRange() 5270 << FixItHint::CreateReplacement(OpLoc, "."); 5271 OpKind = tok::period; 5272 break; 5273 } 5274 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 5275 << BaseType << Base->getSourceRange(); 5276 CallExpr *CE = dyn_cast<CallExpr>(Base); 5277 if (Decl *CD = (CE ? CE->getCalleeDecl() : nullptr)) { 5278 Diag(CD->getLocStart(), 5279 diag::note_member_reference_arrow_from_operator_arrow); 5280 } 5281 } 5282 return ExprError(); 5283 } 5284 Base = Result.get(); 5285 if (CXXOperatorCallExpr *OpCall = dyn_cast<CXXOperatorCallExpr>(Base)) 5286 OperatorArrows.push_back(OpCall->getDirectCallee()); 5287 BaseType = Base->getType(); 5288 CanQualType CBaseType = Context.getCanonicalType(BaseType); 5289 if (!CTypes.insert(CBaseType).second) { 5290 Diag(OpLoc, diag::err_operator_arrow_circular) << StartingType; 5291 noteOperatorArrows(*this, OperatorArrows); 5292 return ExprError(); 5293 } 5294 FirstIteration = false; 5295 } 5296 5297 if (OpKind == tok::arrow && 5298 (BaseType->isPointerType() || BaseType->isObjCObjectPointerType())) 5299 BaseType = BaseType->getPointeeType(); 5300 } 5301 5302 // Objective-C properties allow "." access on Objective-C pointer types, 5303 // so adjust the base type to the object type itself. 5304 if (BaseType->isObjCObjectPointerType()) 5305 BaseType = BaseType->getPointeeType(); 5306 5307 // C++ [basic.lookup.classref]p2: 5308 // [...] If the type of the object expression is of pointer to scalar 5309 // type, the unqualified-id is looked up in the context of the complete 5310 // postfix-expression. 5311 // 5312 // This also indicates that we could be parsing a pseudo-destructor-name. 5313 // Note that Objective-C class and object types can be pseudo-destructor 5314 // expressions or normal member (ivar or property) access expressions. 5315 if (BaseType->isObjCObjectOrInterfaceType()) { 5316 MayBePseudoDestructor = true; 5317 } else if (!BaseType->isRecordType()) { 5318 ObjectType = ParsedType(); 5319 MayBePseudoDestructor = true; 5320 return Base; 5321 } 5322 5323 // The object type must be complete (or dependent), or 5324 // C++11 [expr.prim.general]p3: 5325 // Unlike the object expression in other contexts, *this is not required to 5326 // be of complete type for purposes of class member access (5.2.5) outside 5327 // the member function body. 5328 if (!BaseType->isDependentType() && 5329 !isThisOutsideMemberFunctionBody(BaseType) && 5330 RequireCompleteType(OpLoc, BaseType, diag::err_incomplete_member_access)) 5331 return ExprError(); 5332 5333 // C++ [basic.lookup.classref]p2: 5334 // If the id-expression in a class member access (5.2.5) is an 5335 // unqualified-id, and the type of the object expression is of a class 5336 // type C (or of pointer to a class type C), the unqualified-id is looked 5337 // up in the scope of class C. [...] 5338 ObjectType = ParsedType::make(BaseType); 5339 return Base; 5340} 5341 5342ExprResult Sema::DiagnoseDtorReference(SourceLocation NameLoc, 5343 Expr *MemExpr) { 5344 SourceLocation ExpectedLParenLoc = PP.getLocForEndOfToken(NameLoc); 5345 Diag(MemExpr->getLocStart(), diag::err_dtor_expr_without_call) 5346 << isa<CXXPseudoDestructorExpr>(MemExpr) 5347 << FixItHint::CreateInsertion(ExpectedLParenLoc, "()"); 5348 5349 return ActOnCallExpr(/*Scope*/ nullptr, 5350 MemExpr, 5351 /*LPLoc*/ ExpectedLParenLoc, 5352 None, 5353 /*RPLoc*/ ExpectedLParenLoc); 5354} 5355 5356static bool CheckArrow(Sema& S, QualType& ObjectType, Expr *&Base, 5357 tok::TokenKind& OpKind, SourceLocation OpLoc) { 5358 if (Base->hasPlaceholderType()) { 5359 ExprResult result = S.CheckPlaceholderExpr(Base); 5360 if (result.isInvalid()) return true; 5361 Base = result.get(); 5362 } 5363 ObjectType = Base->getType(); 5364 5365 // C++ [expr.pseudo]p2: 5366 // The left-hand side of the dot operator shall be of scalar type. The 5367 // left-hand side of the arrow operator shall be of pointer to scalar type. 5368 // This scalar type is the object type. 5369 // Note that this is rather different from the normal handling for the 5370 // arrow operator. 5371 if (OpKind == tok::arrow) { 5372 if (const PointerType *Ptr = ObjectType->getAs<PointerType>()) { 5373 ObjectType = Ptr->getPointeeType(); 5374 } else if (!Base->isTypeDependent()) { 5375 // The user wrote "p->" when she probably meant "p."; fix it. 5376 S.Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 5377 << ObjectType << true 5378 << FixItHint::CreateReplacement(OpLoc, "."); 5379 if (S.isSFINAEContext()) 5380 return true; 5381 5382 OpKind = tok::period; 5383 } 5384 } 5385 5386 return false; 5387} 5388 5389ExprResult Sema::BuildPseudoDestructorExpr(Expr *Base, 5390 SourceLocation OpLoc, 5391 tok::TokenKind OpKind, 5392 const CXXScopeSpec &SS, 5393 TypeSourceInfo *ScopeTypeInfo, 5394 SourceLocation CCLoc, 5395 SourceLocation TildeLoc, 5396 PseudoDestructorTypeStorage Destructed, 5397 bool HasTrailingLParen) { 5398 TypeSourceInfo *DestructedTypeInfo = Destructed.getTypeSourceInfo(); 5399 5400 QualType ObjectType; 5401 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) 5402 return ExprError(); 5403 5404 if (!ObjectType->isDependentType() && !ObjectType->isScalarType() && 5405 !ObjectType->isVectorType()) { 5406 if (getLangOpts().MSVCCompat && ObjectType->isVoidType()) 5407 Diag(OpLoc, diag::ext_pseudo_dtor_on_void) << Base->getSourceRange(); 5408 else { 5409 Diag(OpLoc, diag::err_pseudo_dtor_base_not_scalar) 5410 << ObjectType << Base->getSourceRange(); 5411 return ExprError(); 5412 } 5413 } 5414 5415 // C++ [expr.pseudo]p2: 5416 // [...] The cv-unqualified versions of the object type and of the type 5417 // designated by the pseudo-destructor-name shall be the same type. 5418 if (DestructedTypeInfo) { 5419 QualType DestructedType = DestructedTypeInfo->getType(); 5420 SourceLocation DestructedTypeStart 5421 = DestructedTypeInfo->getTypeLoc().getLocalSourceRange().getBegin(); 5422 if (!DestructedType->isDependentType() && !ObjectType->isDependentType()) { 5423 if (!Context.hasSameUnqualifiedType(DestructedType, ObjectType)) { 5424 Diag(DestructedTypeStart, diag::err_pseudo_dtor_type_mismatch) 5425 << ObjectType << DestructedType << Base->getSourceRange() 5426 << DestructedTypeInfo->getTypeLoc().getLocalSourceRange(); 5427 5428 // Recover by setting the destructed type to the object type. 5429 DestructedType = ObjectType; 5430 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(ObjectType, 5431 DestructedTypeStart); 5432 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); 5433 } else if (DestructedType.getObjCLifetime() != 5434 ObjectType.getObjCLifetime()) { 5435 5436 if (DestructedType.getObjCLifetime() == Qualifiers::OCL_None) { 5437 // Okay: just pretend that the user provided the correctly-qualified 5438 // type. 5439 } else { 5440 Diag(DestructedTypeStart, diag::err_arc_pseudo_dtor_inconstant_quals) 5441 << ObjectType << DestructedType << Base->getSourceRange() 5442 << DestructedTypeInfo->getTypeLoc().getLocalSourceRange(); 5443 } 5444 5445 // Recover by setting the destructed type to the object type. 5446 DestructedType = ObjectType; 5447 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(ObjectType, 5448 DestructedTypeStart); 5449 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); 5450 } 5451 } 5452 } 5453 5454 // C++ [expr.pseudo]p2: 5455 // [...] Furthermore, the two type-names in a pseudo-destructor-name of the 5456 // form 5457 // 5458 // ::[opt] nested-name-specifier[opt] type-name :: ~ type-name 5459 // 5460 // shall designate the same scalar type. 5461 if (ScopeTypeInfo) { 5462 QualType ScopeType = ScopeTypeInfo->getType(); 5463 if (!ScopeType->isDependentType() && !ObjectType->isDependentType() && 5464 !Context.hasSameUnqualifiedType(ScopeType, ObjectType)) { 5465 5466 Diag(ScopeTypeInfo->getTypeLoc().getLocalSourceRange().getBegin(), 5467 diag::err_pseudo_dtor_type_mismatch) 5468 << ObjectType << ScopeType << Base->getSourceRange() 5469 << ScopeTypeInfo->getTypeLoc().getLocalSourceRange(); 5470 5471 ScopeType = QualType(); 5472 ScopeTypeInfo = nullptr; 5473 } 5474 } 5475 5476 Expr *Result 5477 = new (Context) CXXPseudoDestructorExpr(Context, Base, 5478 OpKind == tok::arrow, OpLoc, 5479 SS.getWithLocInContext(Context), 5480 ScopeTypeInfo, 5481 CCLoc, 5482 TildeLoc, 5483 Destructed); 5484 5485 if (HasTrailingLParen) 5486 return Result; 5487 5488 return DiagnoseDtorReference(Destructed.getLocation(), Result); 5489} 5490 5491ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base, 5492 SourceLocation OpLoc, 5493 tok::TokenKind OpKind, 5494 CXXScopeSpec &SS, 5495 UnqualifiedId &FirstTypeName, 5496 SourceLocation CCLoc, 5497 SourceLocation TildeLoc, 5498 UnqualifiedId &SecondTypeName, 5499 bool HasTrailingLParen) { 5500 assert((FirstTypeName.getKind() == UnqualifiedId::IK_TemplateId || 5501 FirstTypeName.getKind() == UnqualifiedId::IK_Identifier) && 5502 "Invalid first type name in pseudo-destructor"); 5503 assert((SecondTypeName.getKind() == UnqualifiedId::IK_TemplateId || 5504 SecondTypeName.getKind() == UnqualifiedId::IK_Identifier) && 5505 "Invalid second type name in pseudo-destructor"); 5506 5507 QualType ObjectType; 5508 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) 5509 return ExprError(); 5510 5511 // Compute the object type that we should use for name lookup purposes. Only 5512 // record types and dependent types matter. 5513 ParsedType ObjectTypePtrForLookup; 5514 if (!SS.isSet()) { 5515 if (ObjectType->isRecordType()) 5516 ObjectTypePtrForLookup = ParsedType::make(ObjectType); 5517 else if (ObjectType->isDependentType()) 5518 ObjectTypePtrForLookup = ParsedType::make(Context.DependentTy); 5519 } 5520 5521 // Convert the name of the type being destructed (following the ~) into a 5522 // type (with source-location information). 5523 QualType DestructedType; 5524 TypeSourceInfo *DestructedTypeInfo = nullptr; 5525 PseudoDestructorTypeStorage Destructed; 5526 if (SecondTypeName.getKind() == UnqualifiedId::IK_Identifier) { 5527 ParsedType T = getTypeName(*SecondTypeName.Identifier, 5528 SecondTypeName.StartLocation, 5529 S, &SS, true, false, ObjectTypePtrForLookup); 5530 if (!T && 5531 ((SS.isSet() && !computeDeclContext(SS, false)) || 5532 (!SS.isSet() && ObjectType->isDependentType()))) { 5533 // The name of the type being destroyed is a dependent name, and we 5534 // couldn't find anything useful in scope. Just store the identifier and 5535 // it's location, and we'll perform (qualified) name lookup again at 5536 // template instantiation time. 5537 Destructed = PseudoDestructorTypeStorage(SecondTypeName.Identifier, 5538 SecondTypeName.StartLocation); 5539 } else if (!T) { 5540 Diag(SecondTypeName.StartLocation, 5541 diag::err_pseudo_dtor_destructor_non_type) 5542 << SecondTypeName.Identifier << ObjectType; 5543 if (isSFINAEContext()) 5544 return ExprError(); 5545 5546 // Recover by assuming we had the right type all along. 5547 DestructedType = ObjectType; 5548 } else 5549 DestructedType = GetTypeFromParser(T, &DestructedTypeInfo); 5550 } else { 5551 // Resolve the template-id to a type. 5552 TemplateIdAnnotation *TemplateId = SecondTypeName.TemplateId; 5553 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(), 5554 TemplateId->NumArgs); 5555 TypeResult T = ActOnTemplateIdType(TemplateId->SS, 5556 TemplateId->TemplateKWLoc, 5557 TemplateId->Template, 5558 TemplateId->TemplateNameLoc, 5559 TemplateId->LAngleLoc, 5560 TemplateArgsPtr, 5561 TemplateId->RAngleLoc); 5562 if (T.isInvalid() || !T.get()) { 5563 // Recover by assuming we had the right type all along. 5564 DestructedType = ObjectType; 5565 } else 5566 DestructedType = GetTypeFromParser(T.get(), &DestructedTypeInfo); 5567 } 5568 5569 // If we've performed some kind of recovery, (re-)build the type source 5570 // information. 5571 if (!DestructedType.isNull()) { 5572 if (!DestructedTypeInfo) 5573 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(DestructedType, 5574 SecondTypeName.StartLocation); 5575 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); 5576 } 5577 5578 // Convert the name of the scope type (the type prior to '::') into a type. 5579 TypeSourceInfo *ScopeTypeInfo = nullptr; 5580 QualType ScopeType; 5581 if (FirstTypeName.getKind() == UnqualifiedId::IK_TemplateId || 5582 FirstTypeName.Identifier) { 5583 if (FirstTypeName.getKind() == UnqualifiedId::IK_Identifier) { 5584 ParsedType T = getTypeName(*FirstTypeName.Identifier, 5585 FirstTypeName.StartLocation, 5586 S, &SS, true, false, ObjectTypePtrForLookup); 5587 if (!T) { 5588 Diag(FirstTypeName.StartLocation, 5589 diag::err_pseudo_dtor_destructor_non_type) 5590 << FirstTypeName.Identifier << ObjectType; 5591 5592 if (isSFINAEContext()) 5593 return ExprError(); 5594 5595 // Just drop this type. It's unnecessary anyway. 5596 ScopeType = QualType(); 5597 } else 5598 ScopeType = GetTypeFromParser(T, &ScopeTypeInfo); 5599 } else { 5600 // Resolve the template-id to a type. 5601 TemplateIdAnnotation *TemplateId = FirstTypeName.TemplateId; 5602 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(), 5603 TemplateId->NumArgs); 5604 TypeResult T = ActOnTemplateIdType(TemplateId->SS, 5605 TemplateId->TemplateKWLoc, 5606 TemplateId->Template, 5607 TemplateId->TemplateNameLoc, 5608 TemplateId->LAngleLoc, 5609 TemplateArgsPtr, 5610 TemplateId->RAngleLoc); 5611 if (T.isInvalid() || !T.get()) { 5612 // Recover by dropping this type. 5613 ScopeType = QualType(); 5614 } else 5615 ScopeType = GetTypeFromParser(T.get(), &ScopeTypeInfo); 5616 } 5617 } 5618 5619 if (!ScopeType.isNull() && !ScopeTypeInfo) 5620 ScopeTypeInfo = Context.getTrivialTypeSourceInfo(ScopeType, 5621 FirstTypeName.StartLocation); 5622 5623 5624 return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, SS, 5625 ScopeTypeInfo, CCLoc, TildeLoc, 5626 Destructed, HasTrailingLParen); 5627} 5628 5629ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base, 5630 SourceLocation OpLoc, 5631 tok::TokenKind OpKind, 5632 SourceLocation TildeLoc, 5633 const DeclSpec& DS, 5634 bool HasTrailingLParen) { 5635 QualType ObjectType; 5636 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) 5637 return ExprError(); 5638 5639 QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc(), 5640 false); 5641 5642 TypeLocBuilder TLB; 5643 DecltypeTypeLoc DecltypeTL = TLB.push<DecltypeTypeLoc>(T); 5644 DecltypeTL.setNameLoc(DS.getTypeSpecTypeLoc()); 5645 TypeSourceInfo *DestructedTypeInfo = TLB.getTypeSourceInfo(Context, T); 5646 PseudoDestructorTypeStorage Destructed(DestructedTypeInfo); 5647 5648 return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, CXXScopeSpec(), 5649 nullptr, SourceLocation(), TildeLoc, 5650 Destructed, HasTrailingLParen); 5651} 5652 5653ExprResult Sema::BuildCXXMemberCallExpr(Expr *E, NamedDecl *FoundDecl, 5654 CXXConversionDecl *Method, 5655 bool HadMultipleCandidates) { 5656 if (Method->getParent()->isLambda() && 5657 Method->getConversionType()->isBlockPointerType()) { 5658 // This is a lambda coversion to block pointer; check if the argument 5659 // is a LambdaExpr. 5660 Expr *SubE = E; 5661 CastExpr *CE = dyn_cast<CastExpr>(SubE); 5662 if (CE && CE->getCastKind() == CK_NoOp) 5663 SubE = CE->getSubExpr(); 5664 SubE = SubE->IgnoreParens(); 5665 if (CXXBindTemporaryExpr *BE = dyn_cast<CXXBindTemporaryExpr>(SubE)) 5666 SubE = BE->getSubExpr(); 5667 if (isa<LambdaExpr>(SubE)) { 5668 // For the conversion to block pointer on a lambda expression, we 5669 // construct a special BlockLiteral instead; this doesn't really make 5670 // a difference in ARC, but outside of ARC the resulting block literal 5671 // follows the normal lifetime rules for block literals instead of being 5672 // autoreleased. 5673 DiagnosticErrorTrap Trap(Diags); 5674 ExprResult Exp = BuildBlockForLambdaConversion(E->getExprLoc(), 5675 E->getExprLoc(), 5676 Method, E); 5677 if (Exp.isInvalid()) 5678 Diag(E->getExprLoc(), diag::note_lambda_to_block_conv); 5679 return Exp; 5680 } 5681 } 5682 5683 ExprResult Exp = PerformObjectArgumentInitialization(E, /*Qualifier=*/nullptr, 5684 FoundDecl, Method); 5685 if (Exp.isInvalid()) 5686 return true; 5687 5688 MemberExpr *ME = 5689 new (Context) MemberExpr(Exp.get(), /*IsArrow=*/false, Method, 5690 SourceLocation(), Context.BoundMemberTy, 5691 VK_RValue, OK_Ordinary); 5692 if (HadMultipleCandidates) 5693 ME->setHadMultipleCandidates(true); 5694 MarkMemberReferenced(ME); 5695 5696 QualType ResultType = Method->getReturnType(); 5697 ExprValueKind VK = Expr::getValueKindForType(ResultType); 5698 ResultType = ResultType.getNonLValueExprType(Context); 5699 5700 CXXMemberCallExpr *CE = 5701 new (Context) CXXMemberCallExpr(Context, ME, None, ResultType, VK, 5702 Exp.get()->getLocEnd()); 5703 return CE; 5704} 5705 5706ExprResult Sema::BuildCXXNoexceptExpr(SourceLocation KeyLoc, Expr *Operand, 5707 SourceLocation RParen) { 5708 // If the operand is an unresolved lookup expression, the expression is ill- 5709 // formed per [over.over]p1, because overloaded function names cannot be used 5710 // without arguments except in explicit contexts. 5711 ExprResult R = CheckPlaceholderExpr(Operand); 5712 if (R.isInvalid()) 5713 return R; 5714 5715 // The operand may have been modified when checking the placeholder type. 5716 Operand = R.get(); 5717 5718 if (ActiveTemplateInstantiations.empty() && 5719 Operand->HasSideEffects(Context, false)) { 5720 // The expression operand for noexcept is in an unevaluated expression 5721 // context, so side effects could result in unintended consequences. 5722 Diag(Operand->getExprLoc(), diag::warn_side_effects_unevaluated_context); 5723 } 5724 5725 CanThrowResult CanThrow = canThrow(Operand); 5726 return new (Context) 5727 CXXNoexceptExpr(Context.BoolTy, Operand, CanThrow, KeyLoc, RParen); 5728} 5729 5730ExprResult Sema::ActOnNoexceptExpr(SourceLocation KeyLoc, SourceLocation, 5731 Expr *Operand, SourceLocation RParen) { 5732 return BuildCXXNoexceptExpr(KeyLoc, Operand, RParen); 5733} 5734 5735static bool IsSpecialDiscardedValue(Expr *E) { 5736 // In C++11, discarded-value expressions of a certain form are special, 5737 // according to [expr]p10: 5738 // The lvalue-to-rvalue conversion (4.1) is applied only if the 5739 // expression is an lvalue of volatile-qualified type and it has 5740 // one of the following forms: 5741 E = E->IgnoreParens(); 5742 5743 // - id-expression (5.1.1), 5744 if (isa<DeclRefExpr>(E)) 5745 return true; 5746 5747 // - subscripting (5.2.1), 5748 if (isa<ArraySubscriptExpr>(E)) 5749 return true; 5750 5751 // - class member access (5.2.5), 5752 if (isa<MemberExpr>(E)) 5753 return true; 5754 5755 // - indirection (5.3.1), 5756 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) 5757 if (UO->getOpcode() == UO_Deref) 5758 return true; 5759 5760 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) { 5761 // - pointer-to-member operation (5.5), 5762 if (BO->isPtrMemOp()) 5763 return true; 5764 5765 // - comma expression (5.18) where the right operand is one of the above. 5766 if (BO->getOpcode() == BO_Comma) 5767 return IsSpecialDiscardedValue(BO->getRHS()); 5768 } 5769 5770 // - conditional expression (5.16) where both the second and the third 5771 // operands are one of the above, or 5772 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) 5773 return IsSpecialDiscardedValue(CO->getTrueExpr()) && 5774 IsSpecialDiscardedValue(CO->getFalseExpr()); 5775 // The related edge case of "*x ?: *x". 5776 if (BinaryConditionalOperator *BCO = 5777 dyn_cast<BinaryConditionalOperator>(E)) { 5778 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(BCO->getTrueExpr())) 5779 return IsSpecialDiscardedValue(OVE->getSourceExpr()) && 5780 IsSpecialDiscardedValue(BCO->getFalseExpr()); 5781 } 5782 5783 // Objective-C++ extensions to the rule. 5784 if (isa<PseudoObjectExpr>(E) || isa<ObjCIvarRefExpr>(E)) 5785 return true; 5786 5787 return false; 5788} 5789 5790/// Perform the conversions required for an expression used in a 5791/// context that ignores the result. 5792ExprResult Sema::IgnoredValueConversions(Expr *E) { 5793 if (E->hasPlaceholderType()) { 5794 ExprResult result = CheckPlaceholderExpr(E); 5795 if (result.isInvalid()) return E; 5796 E = result.get(); 5797 } 5798 5799 // C99 6.3.2.1: 5800 // [Except in specific positions,] an lvalue that does not have 5801 // array type is converted to the value stored in the 5802 // designated object (and is no longer an lvalue). 5803 if (E->isRValue()) { 5804 // In C, function designators (i.e. expressions of function type) 5805 // are r-values, but we still want to do function-to-pointer decay 5806 // on them. This is both technically correct and convenient for 5807 // some clients. 5808 if (!getLangOpts().CPlusPlus && E->getType()->isFunctionType()) 5809 return DefaultFunctionArrayConversion(E); 5810 5811 return E; 5812 } 5813 5814 if (getLangOpts().CPlusPlus) { 5815 // The C++11 standard defines the notion of a discarded-value expression; 5816 // normally, we don't need to do anything to handle it, but if it is a 5817 // volatile lvalue with a special form, we perform an lvalue-to-rvalue 5818 // conversion. 5819 if (getLangOpts().CPlusPlus11 && E->isGLValue() && 5820 E->getType().isVolatileQualified() && 5821 IsSpecialDiscardedValue(E)) { 5822 ExprResult Res = DefaultLvalueConversion(E); 5823 if (Res.isInvalid()) 5824 return E; 5825 E = Res.get(); 5826 } 5827 return E; 5828 } 5829 5830 // GCC seems to also exclude expressions of incomplete enum type. 5831 if (const EnumType *T = E->getType()->getAs<EnumType>()) { 5832 if (!T->getDecl()->isComplete()) { 5833 // FIXME: stupid workaround for a codegen bug! 5834 E = ImpCastExprToType(E, Context.VoidTy, CK_ToVoid).get(); 5835 return E; 5836 } 5837 } 5838 5839 ExprResult Res = DefaultFunctionArrayLvalueConversion(E); 5840 if (Res.isInvalid()) 5841 return E; 5842 E = Res.get(); 5843 5844 if (!E->getType()->isVoidType()) 5845 RequireCompleteType(E->getExprLoc(), E->getType(), 5846 diag::err_incomplete_type); 5847 return E; 5848} 5849 5850// If we can unambiguously determine whether Var can never be used 5851// in a constant expression, return true. 5852// - if the variable and its initializer are non-dependent, then 5853// we can unambiguously check if the variable is a constant expression. 5854// - if the initializer is not value dependent - we can determine whether 5855// it can be used to initialize a constant expression. If Init can not 5856// be used to initialize a constant expression we conclude that Var can 5857// never be a constant expression. 5858// - FXIME: if the initializer is dependent, we can still do some analysis and 5859// identify certain cases unambiguously as non-const by using a Visitor: 5860// - such as those that involve odr-use of a ParmVarDecl, involve a new 5861// delete, lambda-expr, dynamic-cast, reinterpret-cast etc... 5862static inline bool VariableCanNeverBeAConstantExpression(VarDecl *Var, 5863 ASTContext &Context) { 5864 if (isa<ParmVarDecl>(Var)) return true; 5865 const VarDecl *DefVD = nullptr; 5866 5867 // If there is no initializer - this can not be a constant expression. 5868 if (!Var->getAnyInitializer(DefVD)) return true; 5869 assert(DefVD); 5870 if (DefVD->isWeak()) return false; 5871 EvaluatedStmt *Eval = DefVD->ensureEvaluatedStmt(); 5872 5873 Expr *Init = cast<Expr>(Eval->Value); 5874 5875 if (Var->getType()->isDependentType() || Init->isValueDependent()) { 5876 // FIXME: Teach the constant evaluator to deal with the non-dependent parts 5877 // of value-dependent expressions, and use it here to determine whether the 5878 // initializer is a potential constant expression. 5879 return false; 5880 } 5881 5882 return !IsVariableAConstantExpression(Var, Context); 5883} 5884 5885/// \brief Check if the current lambda has any potential captures 5886/// that must be captured by any of its enclosing lambdas that are ready to 5887/// capture. If there is a lambda that can capture a nested 5888/// potential-capture, go ahead and do so. Also, check to see if any 5889/// variables are uncaptureable or do not involve an odr-use so do not 5890/// need to be captured. 5891 5892static void CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures( 5893 Expr *const FE, LambdaScopeInfo *const CurrentLSI, Sema &S) { 5894 5895 assert(!S.isUnevaluatedContext()); 5896 assert(S.CurContext->isDependentContext()); 5897 assert(CurrentLSI->CallOperator == S.CurContext && 5898 "The current call operator must be synchronized with Sema's CurContext"); 5899 5900 const bool IsFullExprInstantiationDependent = FE->isInstantiationDependent(); 5901 5902 ArrayRef<const FunctionScopeInfo *> FunctionScopesArrayRef( 5903 S.FunctionScopes.data(), S.FunctionScopes.size()); 5904 5905 // All the potentially captureable variables in the current nested 5906 // lambda (within a generic outer lambda), must be captured by an 5907 // outer lambda that is enclosed within a non-dependent context. 5908 const unsigned NumPotentialCaptures = 5909 CurrentLSI->getNumPotentialVariableCaptures(); 5910 for (unsigned I = 0; I != NumPotentialCaptures; ++I) { 5911 Expr *VarExpr = nullptr; 5912 VarDecl *Var = nullptr; 5913 CurrentLSI->getPotentialVariableCapture(I, Var, VarExpr); 5914 // If the variable is clearly identified as non-odr-used and the full 5915 // expression is not instantiation dependent, only then do we not 5916 // need to check enclosing lambda's for speculative captures. 5917 // For e.g.: 5918 // Even though 'x' is not odr-used, it should be captured. 5919 // int test() { 5920 // const int x = 10; 5921 // auto L = [=](auto a) { 5922 // (void) +x + a; 5923 // }; 5924 // } 5925 if (CurrentLSI->isVariableExprMarkedAsNonODRUsed(VarExpr) && 5926 !IsFullExprInstantiationDependent) 5927 continue; 5928 5929 // If we have a capture-capable lambda for the variable, go ahead and 5930 // capture the variable in that lambda (and all its enclosing lambdas). 5931 if (const Optional<unsigned> Index = 5932 getStackIndexOfNearestEnclosingCaptureCapableLambda( 5933 FunctionScopesArrayRef, Var, S)) { 5934 const unsigned FunctionScopeIndexOfCapturableLambda = Index.getValue(); 5935 MarkVarDeclODRUsed(Var, VarExpr->getExprLoc(), S, 5936 &FunctionScopeIndexOfCapturableLambda); 5937 } 5938 const bool IsVarNeverAConstantExpression = 5939 VariableCanNeverBeAConstantExpression(Var, S.Context); 5940 if (!IsFullExprInstantiationDependent || IsVarNeverAConstantExpression) { 5941 // This full expression is not instantiation dependent or the variable 5942 // can not be used in a constant expression - which means 5943 // this variable must be odr-used here, so diagnose a 5944 // capture violation early, if the variable is un-captureable. 5945 // This is purely for diagnosing errors early. Otherwise, this 5946 // error would get diagnosed when the lambda becomes capture ready. 5947 QualType CaptureType, DeclRefType; 5948 SourceLocation ExprLoc = VarExpr->getExprLoc(); 5949 if (S.tryCaptureVariable(Var, ExprLoc, S.TryCapture_Implicit, 5950 /*EllipsisLoc*/ SourceLocation(), 5951 /*BuildAndDiagnose*/false, CaptureType, 5952 DeclRefType, nullptr)) { 5953 // We will never be able to capture this variable, and we need 5954 // to be able to in any and all instantiations, so diagnose it. 5955 S.tryCaptureVariable(Var, ExprLoc, S.TryCapture_Implicit, 5956 /*EllipsisLoc*/ SourceLocation(), 5957 /*BuildAndDiagnose*/true, CaptureType, 5958 DeclRefType, nullptr); 5959 } 5960 } 5961 } 5962 5963 // Check if 'this' needs to be captured. 5964 if (CurrentLSI->hasPotentialThisCapture()) { 5965 // If we have a capture-capable lambda for 'this', go ahead and capture 5966 // 'this' in that lambda (and all its enclosing lambdas). 5967 if (const Optional<unsigned> Index = 5968 getStackIndexOfNearestEnclosingCaptureCapableLambda( 5969 FunctionScopesArrayRef, /*0 is 'this'*/ nullptr, S)) { 5970 const unsigned FunctionScopeIndexOfCapturableLambda = Index.getValue(); 5971 S.CheckCXXThisCapture(CurrentLSI->PotentialThisCaptureLocation, 5972 /*Explicit*/ false, /*BuildAndDiagnose*/ true, 5973 &FunctionScopeIndexOfCapturableLambda); 5974 } 5975 } 5976 5977 // Reset all the potential captures at the end of each full-expression. 5978 CurrentLSI->clearPotentialCaptures(); 5979} 5980 5981static ExprResult attemptRecovery(Sema &SemaRef, 5982 const TypoCorrectionConsumer &Consumer, 5983 TypoCorrection TC) { 5984 LookupResult R(SemaRef, Consumer.getLookupResult().getLookupNameInfo(), 5985 Consumer.getLookupResult().getLookupKind()); 5986 const CXXScopeSpec *SS = Consumer.getSS(); 5987 CXXScopeSpec NewSS; 5988 5989 // Use an approprate CXXScopeSpec for building the expr. 5990 if (auto *NNS = TC.getCorrectionSpecifier()) 5991 NewSS.MakeTrivial(SemaRef.Context, NNS, TC.getCorrectionRange()); 5992 else if (SS && !TC.WillReplaceSpecifier()) 5993 NewSS = *SS; 5994 5995 if (auto *ND = TC.getCorrectionDecl()) { 5996 R.setLookupName(ND->getDeclName()); 5997 R.addDecl(ND); 5998 if (ND->isCXXClassMember()) { 5999 // Figure out the correct naming class to add to the LookupResult. 6000 CXXRecordDecl *Record = nullptr; 6001 if (auto *NNS = TC.getCorrectionSpecifier()) 6002 Record = NNS->getAsType()->getAsCXXRecordDecl(); 6003 if (!Record) 6004 Record = 6005 dyn_cast<CXXRecordDecl>(ND->getDeclContext()->getRedeclContext()); 6006 if (Record) 6007 R.setNamingClass(Record); 6008 6009 // Detect and handle the case where the decl might be an implicit 6010 // member. 6011 bool MightBeImplicitMember; 6012 if (!Consumer.isAddressOfOperand()) 6013 MightBeImplicitMember = true; 6014 else if (!NewSS.isEmpty()) 6015 MightBeImplicitMember = false; 6016 else if (R.isOverloadedResult()) 6017 MightBeImplicitMember = false; 6018 else if (R.isUnresolvableResult()) 6019 MightBeImplicitMember = true; 6020 else 6021 MightBeImplicitMember = isa<FieldDecl>(ND) || 6022 isa<IndirectFieldDecl>(ND) || 6023 isa<MSPropertyDecl>(ND); 6024 6025 if (MightBeImplicitMember) 6026 return SemaRef.BuildPossibleImplicitMemberExpr( 6027 NewSS, /*TemplateKWLoc*/ SourceLocation(), R, 6028 /*TemplateArgs*/ nullptr); 6029 } else if (auto *Ivar = dyn_cast<ObjCIvarDecl>(ND)) { 6030 return SemaRef.LookupInObjCMethod(R, Consumer.getScope(), 6031 Ivar->getIdentifier()); 6032 } 6033 } 6034 6035 return SemaRef.BuildDeclarationNameExpr(NewSS, R, /*NeedsADL*/ false, 6036 /*AcceptInvalidDecl*/ true); 6037} 6038 6039namespace { 6040class FindTypoExprs : public RecursiveASTVisitor<FindTypoExprs> { 6041 llvm::SmallSetVector<TypoExpr *, 2> &TypoExprs; 6042 6043public: 6044 explicit FindTypoExprs(llvm::SmallSetVector<TypoExpr *, 2> &TypoExprs) 6045 : TypoExprs(TypoExprs) {} 6046 bool VisitTypoExpr(TypoExpr *TE) { 6047 TypoExprs.insert(TE); 6048 return true; 6049 } 6050}; 6051 6052class TransformTypos : public TreeTransform<TransformTypos> { 6053 typedef TreeTransform<TransformTypos> BaseTransform; 6054 6055 llvm::function_ref<ExprResult(Expr *)> ExprFilter; 6056 llvm::SmallSetVector<TypoExpr *, 2> TypoExprs, AmbiguousTypoExprs; 6057 llvm::SmallDenseMap<TypoExpr *, ExprResult, 2> TransformCache; 6058 llvm::SmallDenseMap<OverloadExpr *, Expr *, 4> OverloadResolution; 6059 6060 /// \brief Emit diagnostics for all of the TypoExprs encountered. 6061 /// If the TypoExprs were successfully corrected, then the diagnostics should 6062 /// suggest the corrections. Otherwise the diagnostics will not suggest 6063 /// anything (having been passed an empty TypoCorrection). 6064 void EmitAllDiagnostics() { 6065 for (auto E : TypoExprs) { 6066 TypoExpr *TE = cast<TypoExpr>(E); 6067 auto &State = SemaRef.getTypoExprState(TE); 6068 if (State.DiagHandler) { 6069 TypoCorrection TC = State.Consumer->getCurrentCorrection(); 6070 ExprResult Replacement = TransformCache[TE]; 6071 6072 // Extract the NamedDecl from the transformed TypoExpr and add it to the 6073 // TypoCorrection, replacing the existing decls. This ensures the right 6074 // NamedDecl is used in diagnostics e.g. in the case where overload 6075 // resolution was used to select one from several possible decls that 6076 // had been stored in the TypoCorrection. 6077 if (auto *ND = getDeclFromExpr( 6078 Replacement.isInvalid() ? nullptr : Replacement.get())) 6079 TC.setCorrectionDecl(ND); 6080 6081 State.DiagHandler(TC); 6082 } 6083 SemaRef.clearDelayedTypo(TE); 6084 } 6085 } 6086 6087 /// \brief If corrections for the first TypoExpr have been exhausted for a 6088 /// given combination of the other TypoExprs, retry those corrections against 6089 /// the next combination of substitutions for the other TypoExprs by advancing 6090 /// to the next potential correction of the second TypoExpr. For the second 6091 /// and subsequent TypoExprs, if its stream of corrections has been exhausted, 6092 /// the stream is reset and the next TypoExpr's stream is advanced by one (a 6093 /// TypoExpr's correction stream is advanced by removing the TypoExpr from the 6094 /// TransformCache). Returns true if there is still any untried combinations 6095 /// of corrections. 6096 bool CheckAndAdvanceTypoExprCorrectionStreams() { 6097 for (auto TE : TypoExprs) { 6098 auto &State = SemaRef.getTypoExprState(TE); 6099 TransformCache.erase(TE); 6100 if (!State.Consumer->finished()) 6101 return true; 6102 State.Consumer->resetCorrectionStream(); 6103 } 6104 return false; 6105 } 6106 6107 NamedDecl *getDeclFromExpr(Expr *E) { 6108 if (auto *OE = dyn_cast_or_null<OverloadExpr>(E)) 6109 E = OverloadResolution[OE]; 6110 6111 if (!E) 6112 return nullptr; 6113 if (auto *DRE = dyn_cast<DeclRefExpr>(E)) 6114 return DRE->getDecl(); 6115 if (auto *ME = dyn_cast<MemberExpr>(E)) 6116 return ME->getMemberDecl(); 6117 // FIXME: Add any other expr types that could be be seen by the delayed typo 6118 // correction TreeTransform for which the corresponding TypoCorrection could 6119 // contain multiple decls. 6120 return nullptr; 6121 } 6122 6123 ExprResult TryTransform(Expr *E) { 6124 Sema::SFINAETrap Trap(SemaRef); 6125 ExprResult Res = TransformExpr(E); 6126 if (Trap.hasErrorOccurred() || Res.isInvalid()) 6127 return ExprError(); 6128 6129 return ExprFilter(Res.get()); 6130 } 6131 6132public: 6133 TransformTypos(Sema &SemaRef, llvm::function_ref<ExprResult(Expr *)> Filter) 6134 : BaseTransform(SemaRef), ExprFilter(Filter) {} 6135 6136 ExprResult RebuildCallExpr(Expr *Callee, SourceLocation LParenLoc, 6137 MultiExprArg Args, 6138 SourceLocation RParenLoc, 6139 Expr *ExecConfig = nullptr) { 6140 auto Result = BaseTransform::RebuildCallExpr(Callee, LParenLoc, Args, 6141 RParenLoc, ExecConfig); 6142 if (auto *OE = dyn_cast<OverloadExpr>(Callee)) { 6143 if (Result.isUsable()) { 6144 Expr *ResultCall = Result.get(); 6145 if (auto *BE = dyn_cast<CXXBindTemporaryExpr>(ResultCall)) 6146 ResultCall = BE->getSubExpr(); 6147 if (auto *CE = dyn_cast<CallExpr>(ResultCall)) 6148 OverloadResolution[OE] = CE->getCallee(); 6149 } 6150 } 6151 return Result; 6152 } 6153 6154 ExprResult TransformLambdaExpr(LambdaExpr *E) { return Owned(E); } 6155 6156 ExprResult Transform(Expr *E) { 6157 ExprResult Res; 6158 while (true) { 6159 Res = TryTransform(E); 6160 6161 // Exit if either the transform was valid or if there were no TypoExprs 6162 // to transform that still have any untried correction candidates.. 6163 if (!Res.isInvalid() || 6164 !CheckAndAdvanceTypoExprCorrectionStreams()) 6165 break; 6166 } 6167 6168 // Ensure none of the TypoExprs have multiple typo correction candidates 6169 // with the same edit length that pass all the checks and filters. 6170 // TODO: Properly handle various permutations of possible corrections when 6171 // there is more than one potentially ambiguous typo correction. 6172 while (!AmbiguousTypoExprs.empty()) { 6173 auto TE = AmbiguousTypoExprs.back(); 6174 auto Cached = TransformCache[TE]; 6175 auto &State = SemaRef.getTypoExprState(TE); 6176 State.Consumer->saveCurrentPosition(); 6177 TransformCache.erase(TE); 6178 if (!TryTransform(E).isInvalid()) { 6179 State.Consumer->resetCorrectionStream(); 6180 TransformCache.erase(TE); 6181 Res = ExprError(); 6182 break; 6183 } 6184 AmbiguousTypoExprs.remove(TE); 6185 State.Consumer->restoreSavedPosition(); 6186 TransformCache[TE] = Cached; 6187 } 6188 6189 // Ensure that all of the TypoExprs within the current Expr have been found. 6190 if (!Res.isUsable()) 6191 FindTypoExprs(TypoExprs).TraverseStmt(E); 6192 6193 EmitAllDiagnostics(); 6194 6195 return Res; 6196 } 6197 6198 ExprResult TransformTypoExpr(TypoExpr *E) { 6199 // If the TypoExpr hasn't been seen before, record it. Otherwise, return the 6200 // cached transformation result if there is one and the TypoExpr isn't the 6201 // first one that was encountered. 6202 auto &CacheEntry = TransformCache[E]; 6203 if (!TypoExprs.insert(E) && !CacheEntry.isUnset()) { 6204 return CacheEntry; 6205 } 6206 6207 auto &State = SemaRef.getTypoExprState(E); 6208 assert(State.Consumer && "Cannot transform a cleared TypoExpr"); 6209 6210 // For the first TypoExpr and an uncached TypoExpr, find the next likely 6211 // typo correction and return it. 6212 while (TypoCorrection TC = State.Consumer->getNextCorrection()) { 6213 ExprResult NE = State.RecoveryHandler ? 6214 State.RecoveryHandler(SemaRef, E, TC) : 6215 attemptRecovery(SemaRef, *State.Consumer, TC); 6216 if (!NE.isInvalid()) { 6217 // Check whether there may be a second viable correction with the same 6218 // edit distance; if so, remember this TypoExpr may have an ambiguous 6219 // correction so it can be more thoroughly vetted later. 6220 TypoCorrection Next; 6221 if ((Next = State.Consumer->peekNextCorrection()) && 6222 Next.getEditDistance(false) == TC.getEditDistance(false)) { 6223 AmbiguousTypoExprs.insert(E); 6224 } else { 6225 AmbiguousTypoExprs.remove(E); 6226 } 6227 assert(!NE.isUnset() && 6228 "Typo was transformed into a valid-but-null ExprResult"); 6229 return CacheEntry = NE; 6230 } 6231 } 6232 return CacheEntry = ExprError(); 6233 } 6234}; 6235} 6236 6237ExprResult Sema::CorrectDelayedTyposInExpr( 6238 Expr *E, llvm::function_ref<ExprResult(Expr *)> Filter) { 6239 // If the current evaluation context indicates there are uncorrected typos 6240 // and the current expression isn't guaranteed to not have typos, try to 6241 // resolve any TypoExpr nodes that might be in the expression. 6242 if (E && !ExprEvalContexts.empty() && ExprEvalContexts.back().NumTypos && 6243 (E->isTypeDependent() || E->isValueDependent() || 6244 E->isInstantiationDependent())) { 6245 auto TyposInContext = ExprEvalContexts.back().NumTypos; 6246 assert(TyposInContext < ~0U && "Recursive call of CorrectDelayedTyposInExpr"); 6247 ExprEvalContexts.back().NumTypos = ~0U; 6248 auto TyposResolved = DelayedTypos.size(); 6249 auto Result = TransformTypos(*this, Filter).Transform(E); 6250 ExprEvalContexts.back().NumTypos = TyposInContext; 6251 TyposResolved -= DelayedTypos.size(); 6252 if (Result.isInvalid() || Result.get() != E) { 6253 ExprEvalContexts.back().NumTypos -= TyposResolved; 6254 return Result; 6255 } 6256 assert(TyposResolved == 0 && "Corrected typo but got same Expr back?"); 6257 } 6258 return E; 6259} 6260 6261ExprResult Sema::ActOnFinishFullExpr(Expr *FE, SourceLocation CC, 6262 bool DiscardedValue, 6263 bool IsConstexpr, 6264 bool IsLambdaInitCaptureInitializer) { 6265 ExprResult FullExpr = FE; 6266 6267 if (!FullExpr.get()) 6268 return ExprError(); 6269 6270 // If we are an init-expression in a lambdas init-capture, we should not 6271 // diagnose an unexpanded pack now (will be diagnosed once lambda-expr 6272 // containing full-expression is done). 6273 // template<class ... Ts> void test(Ts ... t) { 6274 // test([&a(t)]() { <-- (t) is an init-expr that shouldn't be diagnosed now. 6275 // return a; 6276 // }() ...); 6277 // } 6278 // FIXME: This is a hack. It would be better if we pushed the lambda scope 6279 // when we parse the lambda introducer, and teach capturing (but not 6280 // unexpanded pack detection) to walk over LambdaScopeInfos which don't have a 6281 // corresponding class yet (that is, have LambdaScopeInfo either represent a 6282 // lambda where we've entered the introducer but not the body, or represent a 6283 // lambda where we've entered the body, depending on where the 6284 // parser/instantiation has got to). 6285 if (!IsLambdaInitCaptureInitializer && 6286 DiagnoseUnexpandedParameterPack(FullExpr.get())) 6287 return ExprError(); 6288 6289 // Top-level expressions default to 'id' when we're in a debugger. 6290 if (DiscardedValue && getLangOpts().DebuggerCastResultToId && 6291 FullExpr.get()->getType() == Context.UnknownAnyTy) { 6292 FullExpr = forceUnknownAnyToType(FullExpr.get(), Context.getObjCIdType()); 6293 if (FullExpr.isInvalid()) 6294 return ExprError(); 6295 } 6296 6297 if (DiscardedValue) { 6298 FullExpr = CheckPlaceholderExpr(FullExpr.get()); 6299 if (FullExpr.isInvalid()) 6300 return ExprError(); 6301 6302 FullExpr = IgnoredValueConversions(FullExpr.get()); 6303 if (FullExpr.isInvalid()) 6304 return ExprError(); 6305 } 6306 6307 FullExpr = CorrectDelayedTyposInExpr(FullExpr.get()); 6308 if (FullExpr.isInvalid()) 6309 return ExprError(); 6310 6311 CheckCompletedExpr(FullExpr.get(), CC, IsConstexpr); 6312 6313 // At the end of this full expression (which could be a deeply nested 6314 // lambda), if there is a potential capture within the nested lambda, 6315 // have the outer capture-able lambda try and capture it. 6316 // Consider the following code: 6317 // void f(int, int); 6318 // void f(const int&, double); 6319 // void foo() { 6320 // const int x = 10, y = 20; 6321 // auto L = [=](auto a) { 6322 // auto M = [=](auto b) { 6323 // f(x, b); <-- requires x to be captured by L and M 6324 // f(y, a); <-- requires y to be captured by L, but not all Ms 6325 // }; 6326 // }; 6327 // } 6328 6329 // FIXME: Also consider what happens for something like this that involves 6330 // the gnu-extension statement-expressions or even lambda-init-captures: 6331 // void f() { 6332 // const int n = 0; 6333 // auto L = [&](auto a) { 6334 // +n + ({ 0; a; }); 6335 // }; 6336 // } 6337 // 6338 // Here, we see +n, and then the full-expression 0; ends, so we don't 6339 // capture n (and instead remove it from our list of potential captures), 6340 // and then the full-expression +n + ({ 0; }); ends, but it's too late 6341 // for us to see that we need to capture n after all. 6342 6343 LambdaScopeInfo *const CurrentLSI = getCurLambda(); 6344 // FIXME: PR 17877 showed that getCurLambda() can return a valid pointer 6345 // even if CurContext is not a lambda call operator. Refer to that Bug Report 6346 // for an example of the code that might cause this asynchrony. 6347 // By ensuring we are in the context of a lambda's call operator 6348 // we can fix the bug (we only need to check whether we need to capture 6349 // if we are within a lambda's body); but per the comments in that 6350 // PR, a proper fix would entail : 6351 // "Alternative suggestion: 6352 // - Add to Sema an integer holding the smallest (outermost) scope 6353 // index that we are *lexically* within, and save/restore/set to 6354 // FunctionScopes.size() in InstantiatingTemplate's 6355 // constructor/destructor. 6356 // - Teach the handful of places that iterate over FunctionScopes to 6357 // stop at the outermost enclosing lexical scope." 6358 const bool IsInLambdaDeclContext = isLambdaCallOperator(CurContext); 6359 if (IsInLambdaDeclContext && CurrentLSI && 6360 CurrentLSI->hasPotentialCaptures() && !FullExpr.isInvalid()) 6361 CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(FE, CurrentLSI, 6362 *this); 6363 return MaybeCreateExprWithCleanups(FullExpr); 6364} 6365 6366StmtResult Sema::ActOnFinishFullStmt(Stmt *FullStmt) { 6367 if (!FullStmt) return StmtError(); 6368 6369 return MaybeCreateStmtWithCleanups(FullStmt); 6370} 6371 6372Sema::IfExistsResult 6373Sema::CheckMicrosoftIfExistsSymbol(Scope *S, 6374 CXXScopeSpec &SS, 6375 const DeclarationNameInfo &TargetNameInfo) { 6376 DeclarationName TargetName = TargetNameInfo.getName(); 6377 if (!TargetName) 6378 return IER_DoesNotExist; 6379 6380 // If the name itself is dependent, then the result is dependent. 6381 if (TargetName.isDependentName()) 6382 return IER_Dependent; 6383 6384 // Do the redeclaration lookup in the current scope. 6385 LookupResult R(*this, TargetNameInfo, Sema::LookupAnyName, 6386 Sema::NotForRedeclaration); 6387 LookupParsedName(R, S, &SS); 6388 R.suppressDiagnostics(); 6389 6390 switch (R.getResultKind()) { 6391 case LookupResult::Found: 6392 case LookupResult::FoundOverloaded: 6393 case LookupResult::FoundUnresolvedValue: 6394 case LookupResult::Ambiguous: 6395 return IER_Exists; 6396 6397 case LookupResult::NotFound: 6398 return IER_DoesNotExist; 6399 6400 case LookupResult::NotFoundInCurrentInstantiation: 6401 return IER_Dependent; 6402 } 6403 6404 llvm_unreachable("Invalid LookupResult Kind!"); 6405} 6406 6407Sema::IfExistsResult 6408Sema::CheckMicrosoftIfExistsSymbol(Scope *S, SourceLocation KeywordLoc, 6409 bool IsIfExists, CXXScopeSpec &SS, 6410 UnqualifiedId &Name) { 6411 DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name); 6412 6413 // Check for unexpanded parameter packs. 6414 SmallVector<UnexpandedParameterPack, 4> Unexpanded; 6415 collectUnexpandedParameterPacks(SS, Unexpanded); 6416 collectUnexpandedParameterPacks(TargetNameInfo, Unexpanded); 6417 if (!Unexpanded.empty()) { 6418 DiagnoseUnexpandedParameterPacks(KeywordLoc, 6419 IsIfExists? UPPC_IfExists 6420 : UPPC_IfNotExists, 6421 Unexpanded); 6422 return IER_Error; 6423 } 6424 6425 return CheckMicrosoftIfExistsSymbol(S, SS, TargetNameInfo); 6426} 6427