SemaExprCXX.cpp revision 3ea9e33ea25e0c2b12db56418ba3f994eb662c04
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 (SS.isInvalid()) 117 return ParsedType(); 118 119 // If we have an object type, it's because we are in a 120 // pseudo-destructor-expression or a member access expression, and 121 // we know what type we're looking for. 122 if (ObjectTypePtr) 123 SearchType = GetTypeFromParser(ObjectTypePtr); 124 125 if (SS.isSet()) { 126 NestedNameSpecifier *NNS = SS.getScopeRep(); 127 128 bool AlreadySearched = false; 129 bool LookAtPrefix = true; 130 // C++11 [basic.lookup.qual]p6: 131 // If a pseudo-destructor-name (5.2.4) contains a nested-name-specifier, 132 // the type-names are looked up as types in the scope designated by the 133 // nested-name-specifier. Similarly, in a qualified-id of the form: 134 // 135 // nested-name-specifier[opt] class-name :: ~ class-name 136 // 137 // the second class-name is looked up in the same scope as the first. 138 // 139 // Here, we determine whether the code below is permitted to look at the 140 // prefix of the nested-name-specifier. 141 DeclContext *DC = computeDeclContext(SS, EnteringContext); 142 if (DC && DC->isFileContext()) { 143 AlreadySearched = true; 144 LookupCtx = DC; 145 isDependent = false; 146 } else if (DC && isa<CXXRecordDecl>(DC)) { 147 LookAtPrefix = false; 148 LookInScope = true; 149 } 150 151 // The second case from the C++03 rules quoted further above. 152 NestedNameSpecifier *Prefix = nullptr; 153 if (AlreadySearched) { 154 // Nothing left to do. 155 } else if (LookAtPrefix && (Prefix = NNS->getPrefix())) { 156 CXXScopeSpec PrefixSS; 157 PrefixSS.Adopt(NestedNameSpecifierLoc(Prefix, SS.location_data())); 158 LookupCtx = computeDeclContext(PrefixSS, EnteringContext); 159 isDependent = isDependentScopeSpecifier(PrefixSS); 160 } else if (ObjectTypePtr) { 161 LookupCtx = computeDeclContext(SearchType); 162 isDependent = SearchType->isDependentType(); 163 } else { 164 LookupCtx = computeDeclContext(SS, EnteringContext); 165 isDependent = LookupCtx && LookupCtx->isDependentContext(); 166 } 167 } else if (ObjectTypePtr) { 168 // C++ [basic.lookup.classref]p3: 169 // If the unqualified-id is ~type-name, the type-name is looked up 170 // in the context of the entire postfix-expression. If the type T 171 // of the object expression is of a class type C, the type-name is 172 // also looked up in the scope of class C. At least one of the 173 // lookups shall find a name that refers to (possibly 174 // cv-qualified) T. 175 LookupCtx = computeDeclContext(SearchType); 176 isDependent = SearchType->isDependentType(); 177 assert((isDependent || !SearchType->isIncompleteType()) && 178 "Caller should have completed object type"); 179 180 LookInScope = true; 181 } else { 182 // Perform lookup into the current scope (only). 183 LookInScope = true; 184 } 185 186 TypeDecl *NonMatchingTypeDecl = nullptr; 187 LookupResult Found(*this, &II, NameLoc, LookupOrdinaryName); 188 for (unsigned Step = 0; Step != 2; ++Step) { 189 // Look for the name first in the computed lookup context (if we 190 // have one) and, if that fails to find a match, in the scope (if 191 // we're allowed to look there). 192 Found.clear(); 193 if (Step == 0 && LookupCtx) 194 LookupQualifiedName(Found, LookupCtx); 195 else if (Step == 1 && LookInScope && S) 196 LookupName(Found, S); 197 else 198 continue; 199 200 // FIXME: Should we be suppressing ambiguities here? 201 if (Found.isAmbiguous()) 202 return ParsedType(); 203 204 if (TypeDecl *Type = Found.getAsSingle<TypeDecl>()) { 205 QualType T = Context.getTypeDeclType(Type); 206 MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false); 207 208 if (SearchType.isNull() || SearchType->isDependentType() || 209 Context.hasSameUnqualifiedType(T, SearchType)) { 210 // We found our type! 211 212 return CreateParsedType(T, 213 Context.getTrivialTypeSourceInfo(T, NameLoc)); 214 } 215 216 if (!SearchType.isNull()) 217 NonMatchingTypeDecl = Type; 218 } 219 220 // If the name that we found is a class template name, and it is 221 // the same name as the template name in the last part of the 222 // nested-name-specifier (if present) or the object type, then 223 // this is the destructor for that class. 224 // FIXME: This is a workaround until we get real drafting for core 225 // issue 399, for which there isn't even an obvious direction. 226 if (ClassTemplateDecl *Template = Found.getAsSingle<ClassTemplateDecl>()) { 227 QualType MemberOfType; 228 if (SS.isSet()) { 229 if (DeclContext *Ctx = computeDeclContext(SS, EnteringContext)) { 230 // Figure out the type of the context, if it has one. 231 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) 232 MemberOfType = Context.getTypeDeclType(Record); 233 } 234 } 235 if (MemberOfType.isNull()) 236 MemberOfType = SearchType; 237 238 if (MemberOfType.isNull()) 239 continue; 240 241 // We're referring into a class template specialization. If the 242 // class template we found is the same as the template being 243 // specialized, we found what we are looking for. 244 if (const RecordType *Record = MemberOfType->getAs<RecordType>()) { 245 if (ClassTemplateSpecializationDecl *Spec 246 = dyn_cast<ClassTemplateSpecializationDecl>(Record->getDecl())) { 247 if (Spec->getSpecializedTemplate()->getCanonicalDecl() == 248 Template->getCanonicalDecl()) 249 return CreateParsedType( 250 MemberOfType, 251 Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc)); 252 } 253 254 continue; 255 } 256 257 // We're referring to an unresolved class template 258 // specialization. Determine whether we class template we found 259 // is the same as the template being specialized or, if we don't 260 // know which template is being specialized, that it at least 261 // has the same name. 262 if (const TemplateSpecializationType *SpecType 263 = MemberOfType->getAs<TemplateSpecializationType>()) { 264 TemplateName SpecName = SpecType->getTemplateName(); 265 266 // The class template we found is the same template being 267 // specialized. 268 if (TemplateDecl *SpecTemplate = SpecName.getAsTemplateDecl()) { 269 if (SpecTemplate->getCanonicalDecl() == Template->getCanonicalDecl()) 270 return CreateParsedType( 271 MemberOfType, 272 Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc)); 273 274 continue; 275 } 276 277 // The class template we found has the same name as the 278 // (dependent) template name being specialized. 279 if (DependentTemplateName *DepTemplate 280 = SpecName.getAsDependentTemplateName()) { 281 if (DepTemplate->isIdentifier() && 282 DepTemplate->getIdentifier() == Template->getIdentifier()) 283 return CreateParsedType( 284 MemberOfType, 285 Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc)); 286 287 continue; 288 } 289 } 290 } 291 } 292 293 if (isDependent) { 294 // We didn't find our type, but that's okay: it's dependent 295 // anyway. 296 297 // FIXME: What if we have no nested-name-specifier? 298 QualType T = CheckTypenameType(ETK_None, SourceLocation(), 299 SS.getWithLocInContext(Context), 300 II, NameLoc); 301 return ParsedType::make(T); 302 } 303 304 if (NonMatchingTypeDecl) { 305 QualType T = Context.getTypeDeclType(NonMatchingTypeDecl); 306 Diag(NameLoc, diag::err_destructor_expr_type_mismatch) 307 << T << SearchType; 308 Diag(NonMatchingTypeDecl->getLocation(), diag::note_destructor_type_here) 309 << T; 310 } else if (ObjectTypePtr) 311 Diag(NameLoc, diag::err_ident_in_dtor_not_a_type) 312 << &II; 313 else { 314 SemaDiagnosticBuilder DtorDiag = Diag(NameLoc, 315 diag::err_destructor_class_name); 316 if (S) { 317 const DeclContext *Ctx = S->getEntity(); 318 if (const CXXRecordDecl *Class = dyn_cast_or_null<CXXRecordDecl>(Ctx)) 319 DtorDiag << FixItHint::CreateReplacement(SourceRange(NameLoc), 320 Class->getNameAsString()); 321 } 322 } 323 324 return ParsedType(); 325} 326 327ParsedType Sema::getDestructorType(const DeclSpec& DS, ParsedType ObjectType) { 328 if (DS.getTypeSpecType() == DeclSpec::TST_error || !ObjectType) 329 return ParsedType(); 330 assert(DS.getTypeSpecType() == DeclSpec::TST_decltype 331 && "only get destructor types from declspecs"); 332 QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc()); 333 QualType SearchType = GetTypeFromParser(ObjectType); 334 if (SearchType->isDependentType() || Context.hasSameUnqualifiedType(SearchType, T)) { 335 return ParsedType::make(T); 336 } 337 338 Diag(DS.getTypeSpecTypeLoc(), diag::err_destructor_expr_type_mismatch) 339 << T << SearchType; 340 return ParsedType(); 341} 342 343bool Sema::checkLiteralOperatorId(const CXXScopeSpec &SS, 344 const UnqualifiedId &Name) { 345 assert(Name.getKind() == UnqualifiedId::IK_LiteralOperatorId); 346 347 if (!SS.isValid()) 348 return false; 349 350 switch (SS.getScopeRep()->getKind()) { 351 case NestedNameSpecifier::Identifier: 352 case NestedNameSpecifier::TypeSpec: 353 case NestedNameSpecifier::TypeSpecWithTemplate: 354 // Per C++11 [over.literal]p2, literal operators can only be declared at 355 // namespace scope. Therefore, this unqualified-id cannot name anything. 356 // Reject it early, because we have no AST representation for this in the 357 // case where the scope is dependent. 358 Diag(Name.getLocStart(), diag::err_literal_operator_id_outside_namespace) 359 << SS.getScopeRep(); 360 return true; 361 362 case NestedNameSpecifier::Global: 363 case NestedNameSpecifier::Super: 364 case NestedNameSpecifier::Namespace: 365 case NestedNameSpecifier::NamespaceAlias: 366 return false; 367 } 368 369 llvm_unreachable("unknown nested name specifier kind"); 370} 371 372/// \brief Build a C++ typeid expression with a type operand. 373ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType, 374 SourceLocation TypeidLoc, 375 TypeSourceInfo *Operand, 376 SourceLocation RParenLoc) { 377 // C++ [expr.typeid]p4: 378 // The top-level cv-qualifiers of the lvalue expression or the type-id 379 // that is the operand of typeid are always ignored. 380 // If the type of the type-id is a class type or a reference to a class 381 // type, the class shall be completely-defined. 382 Qualifiers Quals; 383 QualType T 384 = Context.getUnqualifiedArrayType(Operand->getType().getNonReferenceType(), 385 Quals); 386 if (T->getAs<RecordType>() && 387 RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid)) 388 return ExprError(); 389 390 if (T->isVariablyModifiedType()) 391 return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid) << T); 392 393 return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), Operand, 394 SourceRange(TypeidLoc, RParenLoc)); 395} 396 397/// \brief Build a C++ typeid expression with an expression operand. 398ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType, 399 SourceLocation TypeidLoc, 400 Expr *E, 401 SourceLocation RParenLoc) { 402 bool WasEvaluated = false; 403 if (E && !E->isTypeDependent()) { 404 if (E->getType()->isPlaceholderType()) { 405 ExprResult result = CheckPlaceholderExpr(E); 406 if (result.isInvalid()) return ExprError(); 407 E = result.get(); 408 } 409 410 QualType T = E->getType(); 411 if (const RecordType *RecordT = T->getAs<RecordType>()) { 412 CXXRecordDecl *RecordD = cast<CXXRecordDecl>(RecordT->getDecl()); 413 // C++ [expr.typeid]p3: 414 // [...] If the type of the expression is a class type, the class 415 // shall be completely-defined. 416 if (RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid)) 417 return ExprError(); 418 419 // C++ [expr.typeid]p3: 420 // When typeid is applied to an expression other than an glvalue of a 421 // polymorphic class type [...] [the] expression is an unevaluated 422 // operand. [...] 423 if (RecordD->isPolymorphic() && E->isGLValue()) { 424 // The subexpression is potentially evaluated; switch the context 425 // and recheck the subexpression. 426 ExprResult Result = TransformToPotentiallyEvaluated(E); 427 if (Result.isInvalid()) return ExprError(); 428 E = Result.get(); 429 430 // We require a vtable to query the type at run time. 431 MarkVTableUsed(TypeidLoc, RecordD); 432 WasEvaluated = true; 433 } 434 } 435 436 // C++ [expr.typeid]p4: 437 // [...] If the type of the type-id is a reference to a possibly 438 // cv-qualified type, the result of the typeid expression refers to a 439 // std::type_info object representing the cv-unqualified referenced 440 // type. 441 Qualifiers Quals; 442 QualType UnqualT = Context.getUnqualifiedArrayType(T, Quals); 443 if (!Context.hasSameType(T, UnqualT)) { 444 T = UnqualT; 445 E = ImpCastExprToType(E, UnqualT, CK_NoOp, E->getValueKind()).get(); 446 } 447 } 448 449 if (E->getType()->isVariablyModifiedType()) 450 return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid) 451 << E->getType()); 452 else if (ActiveTemplateInstantiations.empty() && 453 E->HasSideEffects(Context, WasEvaluated)) { 454 // The expression operand for typeid is in an unevaluated expression 455 // context, so side effects could result in unintended consequences. 456 Diag(E->getExprLoc(), WasEvaluated 457 ? diag::warn_side_effects_typeid 458 : diag::warn_side_effects_unevaluated_context); 459 } 460 461 return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), E, 462 SourceRange(TypeidLoc, RParenLoc)); 463} 464 465/// ActOnCXXTypeidOfType - Parse typeid( type-id ) or typeid (expression); 466ExprResult 467Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc, 468 bool isType, void *TyOrExpr, SourceLocation RParenLoc) { 469 // Find the std::type_info type. 470 if (!getStdNamespace()) 471 return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid)); 472 473 if (!CXXTypeInfoDecl) { 474 IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info"); 475 LookupResult R(*this, TypeInfoII, SourceLocation(), LookupTagName); 476 LookupQualifiedName(R, getStdNamespace()); 477 CXXTypeInfoDecl = R.getAsSingle<RecordDecl>(); 478 // Microsoft's typeinfo doesn't have type_info in std but in the global 479 // namespace if _HAS_EXCEPTIONS is defined to 0. See PR13153. 480 if (!CXXTypeInfoDecl && LangOpts.MSVCCompat) { 481 LookupQualifiedName(R, Context.getTranslationUnitDecl()); 482 CXXTypeInfoDecl = R.getAsSingle<RecordDecl>(); 483 } 484 if (!CXXTypeInfoDecl) 485 return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid)); 486 } 487 488 if (!getLangOpts().RTTI) { 489 return ExprError(Diag(OpLoc, diag::err_no_typeid_with_fno_rtti)); 490 } 491 492 QualType TypeInfoType = Context.getTypeDeclType(CXXTypeInfoDecl); 493 494 if (isType) { 495 // The operand is a type; handle it as such. 496 TypeSourceInfo *TInfo = nullptr; 497 QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr), 498 &TInfo); 499 if (T.isNull()) 500 return ExprError(); 501 502 if (!TInfo) 503 TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc); 504 505 return BuildCXXTypeId(TypeInfoType, OpLoc, TInfo, RParenLoc); 506 } 507 508 // The operand is an expression. 509 return BuildCXXTypeId(TypeInfoType, OpLoc, (Expr*)TyOrExpr, RParenLoc); 510} 511 512/// \brief Build a Microsoft __uuidof expression with a type operand. 513ExprResult Sema::BuildCXXUuidof(QualType TypeInfoType, 514 SourceLocation TypeidLoc, 515 TypeSourceInfo *Operand, 516 SourceLocation RParenLoc) { 517 if (!Operand->getType()->isDependentType()) { 518 bool HasMultipleGUIDs = false; 519 if (!CXXUuidofExpr::GetUuidAttrOfType(Operand->getType(), 520 &HasMultipleGUIDs)) { 521 if (HasMultipleGUIDs) 522 return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids)); 523 else 524 return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid)); 525 } 526 } 527 528 return new (Context) CXXUuidofExpr(TypeInfoType.withConst(), Operand, 529 SourceRange(TypeidLoc, RParenLoc)); 530} 531 532/// \brief Build a Microsoft __uuidof expression with an expression operand. 533ExprResult Sema::BuildCXXUuidof(QualType TypeInfoType, 534 SourceLocation TypeidLoc, 535 Expr *E, 536 SourceLocation RParenLoc) { 537 if (!E->getType()->isDependentType()) { 538 bool HasMultipleGUIDs = false; 539 if (!CXXUuidofExpr::GetUuidAttrOfType(E->getType(), &HasMultipleGUIDs) && 540 !E->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 541 if (HasMultipleGUIDs) 542 return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids)); 543 else 544 return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid)); 545 } 546 } 547 548 return new (Context) CXXUuidofExpr(TypeInfoType.withConst(), E, 549 SourceRange(TypeidLoc, RParenLoc)); 550} 551 552/// ActOnCXXUuidof - Parse __uuidof( type-id ) or __uuidof (expression); 553ExprResult 554Sema::ActOnCXXUuidof(SourceLocation OpLoc, SourceLocation LParenLoc, 555 bool isType, void *TyOrExpr, SourceLocation RParenLoc) { 556 // If MSVCGuidDecl has not been cached, do the lookup. 557 if (!MSVCGuidDecl) { 558 IdentifierInfo *GuidII = &PP.getIdentifierTable().get("_GUID"); 559 LookupResult R(*this, GuidII, SourceLocation(), LookupTagName); 560 LookupQualifiedName(R, Context.getTranslationUnitDecl()); 561 MSVCGuidDecl = R.getAsSingle<RecordDecl>(); 562 if (!MSVCGuidDecl) 563 return ExprError(Diag(OpLoc, diag::err_need_header_before_ms_uuidof)); 564 } 565 566 QualType GuidType = Context.getTypeDeclType(MSVCGuidDecl); 567 568 if (isType) { 569 // The operand is a type; handle it as such. 570 TypeSourceInfo *TInfo = nullptr; 571 QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr), 572 &TInfo); 573 if (T.isNull()) 574 return ExprError(); 575 576 if (!TInfo) 577 TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc); 578 579 return BuildCXXUuidof(GuidType, OpLoc, TInfo, RParenLoc); 580 } 581 582 // The operand is an expression. 583 return BuildCXXUuidof(GuidType, OpLoc, (Expr*)TyOrExpr, RParenLoc); 584} 585 586/// ActOnCXXBoolLiteral - Parse {true,false} literals. 587ExprResult 588Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) { 589 assert((Kind == tok::kw_true || Kind == tok::kw_false) && 590 "Unknown C++ Boolean value!"); 591 return new (Context) 592 CXXBoolLiteralExpr(Kind == tok::kw_true, Context.BoolTy, OpLoc); 593} 594 595/// ActOnCXXNullPtrLiteral - Parse 'nullptr'. 596ExprResult 597Sema::ActOnCXXNullPtrLiteral(SourceLocation Loc) { 598 return new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc); 599} 600 601/// ActOnCXXThrow - Parse throw expressions. 602ExprResult 603Sema::ActOnCXXThrow(Scope *S, SourceLocation OpLoc, Expr *Ex) { 604 bool IsThrownVarInScope = false; 605 if (Ex) { 606 // C++0x [class.copymove]p31: 607 // When certain criteria are met, an implementation is allowed to omit the 608 // copy/move construction of a class object [...] 609 // 610 // - in a throw-expression, when the operand is the name of a 611 // non-volatile automatic object (other than a function or catch- 612 // clause parameter) whose scope does not extend beyond the end of the 613 // innermost enclosing try-block (if there is one), the copy/move 614 // operation from the operand to the exception object (15.1) can be 615 // omitted by constructing the automatic object directly into the 616 // exception object 617 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Ex->IgnoreParens())) 618 if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) { 619 if (Var->hasLocalStorage() && !Var->getType().isVolatileQualified()) { 620 for( ; S; S = S->getParent()) { 621 if (S->isDeclScope(Var)) { 622 IsThrownVarInScope = true; 623 break; 624 } 625 626 if (S->getFlags() & 627 (Scope::FnScope | Scope::ClassScope | Scope::BlockScope | 628 Scope::FunctionPrototypeScope | Scope::ObjCMethodScope | 629 Scope::TryScope)) 630 break; 631 } 632 } 633 } 634 } 635 636 return BuildCXXThrow(OpLoc, Ex, IsThrownVarInScope); 637} 638 639ExprResult Sema::BuildCXXThrow(SourceLocation OpLoc, Expr *Ex, 640 bool IsThrownVarInScope) { 641 // Don't report an error if 'throw' is used in system headers. 642 if (!getLangOpts().CXXExceptions && 643 !getSourceManager().isInSystemHeader(OpLoc)) 644 Diag(OpLoc, diag::err_exceptions_disabled) << "throw"; 645 646 if (getCurScope() && getCurScope()->isOpenMPSimdDirectiveScope()) 647 Diag(OpLoc, diag::err_omp_simd_region_cannot_use_stmt) << "throw"; 648 649 if (Ex && !Ex->isTypeDependent()) { 650 QualType ExceptionObjectTy = Context.getExceptionObjectType(Ex->getType()); 651 if (CheckCXXThrowOperand(OpLoc, ExceptionObjectTy, Ex)) 652 return ExprError(); 653 654 // Initialize the exception result. This implicitly weeds out 655 // abstract types or types with inaccessible copy constructors. 656 657 // C++0x [class.copymove]p31: 658 // When certain criteria are met, an implementation is allowed to omit the 659 // copy/move construction of a class object [...] 660 // 661 // - in a throw-expression, when the operand is the name of a 662 // non-volatile automatic object (other than a function or 663 // catch-clause 664 // parameter) whose scope does not extend beyond the end of the 665 // innermost enclosing try-block (if there is one), the copy/move 666 // operation from the operand to the exception object (15.1) can be 667 // omitted by constructing the automatic object directly into the 668 // exception object 669 const VarDecl *NRVOVariable = nullptr; 670 if (IsThrownVarInScope) 671 NRVOVariable = getCopyElisionCandidate(QualType(), Ex, false); 672 673 InitializedEntity Entity = InitializedEntity::InitializeException( 674 OpLoc, ExceptionObjectTy, 675 /*NRVO=*/NRVOVariable != nullptr); 676 ExprResult Res = PerformMoveOrCopyInitialization( 677 Entity, NRVOVariable, QualType(), Ex, IsThrownVarInScope); 678 if (Res.isInvalid()) 679 return ExprError(); 680 Ex = Res.get(); 681 } 682 683 return new (Context) 684 CXXThrowExpr(Ex, Context.VoidTy, OpLoc, IsThrownVarInScope); 685} 686 687static void 688collectPublicBases(CXXRecordDecl *RD, 689 llvm::DenseMap<CXXRecordDecl *, unsigned> &SubobjectsSeen, 690 llvm::SmallPtrSetImpl<CXXRecordDecl *> &VBases, 691 llvm::SetVector<CXXRecordDecl *> &PublicSubobjectsSeen, 692 bool ParentIsPublic) { 693 for (const CXXBaseSpecifier &BS : RD->bases()) { 694 CXXRecordDecl *BaseDecl = BS.getType()->getAsCXXRecordDecl(); 695 bool NewSubobject; 696 // Virtual bases constitute the same subobject. Non-virtual bases are 697 // always distinct subobjects. 698 if (BS.isVirtual()) 699 NewSubobject = VBases.insert(BaseDecl).second; 700 else 701 NewSubobject = true; 702 703 if (NewSubobject) 704 ++SubobjectsSeen[BaseDecl]; 705 706 // Only add subobjects which have public access throughout the entire chain. 707 bool PublicPath = ParentIsPublic && BS.getAccessSpecifier() == AS_public; 708 if (PublicPath) 709 PublicSubobjectsSeen.insert(BaseDecl); 710 711 // Recurse on to each base subobject. 712 collectPublicBases(BaseDecl, SubobjectsSeen, VBases, PublicSubobjectsSeen, 713 PublicPath); 714 } 715} 716 717static void getUnambiguousPublicSubobjects( 718 CXXRecordDecl *RD, llvm::SmallVectorImpl<CXXRecordDecl *> &Objects) { 719 llvm::DenseMap<CXXRecordDecl *, unsigned> SubobjectsSeen; 720 llvm::SmallSet<CXXRecordDecl *, 2> VBases; 721 llvm::SetVector<CXXRecordDecl *> PublicSubobjectsSeen; 722 SubobjectsSeen[RD] = 1; 723 PublicSubobjectsSeen.insert(RD); 724 collectPublicBases(RD, SubobjectsSeen, VBases, PublicSubobjectsSeen, 725 /*ParentIsPublic=*/true); 726 727 for (CXXRecordDecl *PublicSubobject : PublicSubobjectsSeen) { 728 // Skip ambiguous objects. 729 if (SubobjectsSeen[PublicSubobject] > 1) 730 continue; 731 732 Objects.push_back(PublicSubobject); 733 } 734} 735 736/// CheckCXXThrowOperand - Validate the operand of a throw. 737bool Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc, 738 QualType ExceptionObjectTy, Expr *E) { 739 // If the type of the exception would be an incomplete type or a pointer 740 // to an incomplete type other than (cv) void the program is ill-formed. 741 QualType Ty = ExceptionObjectTy; 742 bool isPointer = false; 743 if (const PointerType* Ptr = Ty->getAs<PointerType>()) { 744 Ty = Ptr->getPointeeType(); 745 isPointer = true; 746 } 747 if (!isPointer || !Ty->isVoidType()) { 748 if (RequireCompleteType(ThrowLoc, Ty, 749 isPointer ? diag::err_throw_incomplete_ptr 750 : diag::err_throw_incomplete, 751 E->getSourceRange())) 752 return true; 753 754 if (RequireNonAbstractType(ThrowLoc, ExceptionObjectTy, 755 diag::err_throw_abstract_type, E)) 756 return true; 757 } 758 759 // If the exception has class type, we need additional handling. 760 CXXRecordDecl *RD = Ty->getAsCXXRecordDecl(); 761 if (!RD) 762 return false; 763 764 // If we are throwing a polymorphic class type or pointer thereof, 765 // exception handling will make use of the vtable. 766 MarkVTableUsed(ThrowLoc, RD); 767 768 // If a pointer is thrown, the referenced object will not be destroyed. 769 if (isPointer) 770 return false; 771 772 // If the class has a destructor, we must be able to call it. 773 if (!RD->hasIrrelevantDestructor()) { 774 if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) { 775 MarkFunctionReferenced(E->getExprLoc(), Destructor); 776 CheckDestructorAccess(E->getExprLoc(), Destructor, 777 PDiag(diag::err_access_dtor_exception) << Ty); 778 if (DiagnoseUseOfDecl(Destructor, E->getExprLoc())) 779 return true; 780 } 781 } 782 783 // The MSVC ABI creates a list of all types which can catch the exception 784 // object. This list also references the appropriate copy constructor to call 785 // if the object is caught by value and has a non-trivial copy constructor. 786 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) { 787 // We are only interested in the public, unambiguous bases contained within 788 // the exception object. Bases which are ambiguous or otherwise 789 // inaccessible are not catchable types. 790 llvm::SmallVector<CXXRecordDecl *, 2> UnambiguousPublicSubobjects; 791 getUnambiguousPublicSubobjects(RD, UnambiguousPublicSubobjects); 792 793 for (CXXRecordDecl *Subobject : UnambiguousPublicSubobjects) { 794 // Attempt to lookup the copy constructor. Various pieces of machinery 795 // will spring into action, like template instantiation, which means this 796 // cannot be a simple walk of the class's decls. Instead, we must perform 797 // lookup and overload resolution. 798 CXXConstructorDecl *CD = LookupCopyingConstructor(Subobject, 0); 799 if (!CD) 800 continue; 801 802 // Mark the constructor referenced as it is used by this throw expression. 803 MarkFunctionReferenced(E->getExprLoc(), CD); 804 805 // Skip this copy constructor if it is trivial, we don't need to record it 806 // in the catchable type data. 807 if (CD->isTrivial()) 808 continue; 809 810 // The copy constructor is non-trivial, create a mapping from this class 811 // type to this constructor. 812 // N.B. The selection of copy constructor is not sensitive to this 813 // particular throw-site. Lookup will be performed at the catch-site to 814 // ensure that the copy constructor is, in fact, accessible (via 815 // friendship or any other means). 816 Context.addCopyConstructorForExceptionObject(Subobject, CD); 817 818 // We don't keep the instantiated default argument expressions around so 819 // we must rebuild them here. 820 for (unsigned I = 1, E = CD->getNumParams(); I != E; ++I) { 821 // Skip any default arguments that we've already instantiated. 822 if (Context.getDefaultArgExprForConstructor(CD, I)) 823 continue; 824 825 Expr *DefaultArg = 826 BuildCXXDefaultArgExpr(ThrowLoc, CD, CD->getParamDecl(I)).get(); 827 Context.addDefaultArgExprForConstructor(CD, I, DefaultArg); 828 } 829 } 830 } 831 832 return false; 833} 834 835QualType Sema::getCurrentThisType() { 836 DeclContext *DC = getFunctionLevelDeclContext(); 837 QualType ThisTy = CXXThisTypeOverride; 838 if (CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(DC)) { 839 if (method && method->isInstance()) 840 ThisTy = method->getThisType(Context); 841 } 842 if (ThisTy.isNull()) { 843 if (isGenericLambdaCallOperatorSpecialization(CurContext) && 844 CurContext->getParent()->getParent()->isRecord()) { 845 // This is a generic lambda call operator that is being instantiated 846 // within a default initializer - so use the enclosing class as 'this'. 847 // There is no enclosing member function to retrieve the 'this' pointer 848 // from. 849 QualType ClassTy = Context.getTypeDeclType( 850 cast<CXXRecordDecl>(CurContext->getParent()->getParent())); 851 // There are no cv-qualifiers for 'this' within default initializers, 852 // per [expr.prim.general]p4. 853 return Context.getPointerType(ClassTy); 854 } 855 } 856 return ThisTy; 857} 858 859Sema::CXXThisScopeRAII::CXXThisScopeRAII(Sema &S, 860 Decl *ContextDecl, 861 unsigned CXXThisTypeQuals, 862 bool Enabled) 863 : S(S), OldCXXThisTypeOverride(S.CXXThisTypeOverride), Enabled(false) 864{ 865 if (!Enabled || !ContextDecl) 866 return; 867 868 CXXRecordDecl *Record = nullptr; 869 if (ClassTemplateDecl *Template = dyn_cast<ClassTemplateDecl>(ContextDecl)) 870 Record = Template->getTemplatedDecl(); 871 else 872 Record = cast<CXXRecordDecl>(ContextDecl); 873 874 S.CXXThisTypeOverride 875 = S.Context.getPointerType( 876 S.Context.getRecordType(Record).withCVRQualifiers(CXXThisTypeQuals)); 877 878 this->Enabled = true; 879} 880 881 882Sema::CXXThisScopeRAII::~CXXThisScopeRAII() { 883 if (Enabled) { 884 S.CXXThisTypeOverride = OldCXXThisTypeOverride; 885 } 886} 887 888static Expr *captureThis(ASTContext &Context, RecordDecl *RD, 889 QualType ThisTy, SourceLocation Loc) { 890 FieldDecl *Field 891 = FieldDecl::Create(Context, RD, Loc, Loc, nullptr, ThisTy, 892 Context.getTrivialTypeSourceInfo(ThisTy, Loc), 893 nullptr, false, ICIS_NoInit); 894 Field->setImplicit(true); 895 Field->setAccess(AS_private); 896 RD->addDecl(Field); 897 return new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit*/true); 898} 899 900bool Sema::CheckCXXThisCapture(SourceLocation Loc, bool Explicit, 901 bool BuildAndDiagnose, const unsigned *const FunctionScopeIndexToStopAt) { 902 // We don't need to capture this in an unevaluated context. 903 if (isUnevaluatedContext() && !Explicit) 904 return true; 905 906 const unsigned MaxFunctionScopesIndex = FunctionScopeIndexToStopAt ? 907 *FunctionScopeIndexToStopAt : FunctionScopes.size() - 1; 908 // Otherwise, check that we can capture 'this'. 909 unsigned NumClosures = 0; 910 for (unsigned idx = MaxFunctionScopesIndex; idx != 0; idx--) { 911 if (CapturingScopeInfo *CSI = 912 dyn_cast<CapturingScopeInfo>(FunctionScopes[idx])) { 913 if (CSI->CXXThisCaptureIndex != 0) { 914 // 'this' is already being captured; there isn't anything more to do. 915 break; 916 } 917 LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI); 918 if (LSI && isGenericLambdaCallOperatorSpecialization(LSI->CallOperator)) { 919 // This context can't implicitly capture 'this'; fail out. 920 if (BuildAndDiagnose) 921 Diag(Loc, diag::err_this_capture) << Explicit; 922 return true; 923 } 924 if (CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByref || 925 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval || 926 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_Block || 927 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_CapturedRegion || 928 Explicit) { 929 // This closure can capture 'this'; continue looking upwards. 930 NumClosures++; 931 Explicit = false; 932 continue; 933 } 934 // This context can't implicitly capture 'this'; fail out. 935 if (BuildAndDiagnose) 936 Diag(Loc, diag::err_this_capture) << Explicit; 937 return true; 938 } 939 break; 940 } 941 if (!BuildAndDiagnose) return false; 942 // Mark that we're implicitly capturing 'this' in all the scopes we skipped. 943 // FIXME: We need to delay this marking in PotentiallyPotentiallyEvaluated 944 // contexts. 945 for (unsigned idx = MaxFunctionScopesIndex; NumClosures; 946 --idx, --NumClosures) { 947 CapturingScopeInfo *CSI = cast<CapturingScopeInfo>(FunctionScopes[idx]); 948 Expr *ThisExpr = nullptr; 949 QualType ThisTy = getCurrentThisType(); 950 if (LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI)) 951 // For lambda expressions, build a field and an initializing expression. 952 ThisExpr = captureThis(Context, LSI->Lambda, ThisTy, Loc); 953 else if (CapturedRegionScopeInfo *RSI 954 = dyn_cast<CapturedRegionScopeInfo>(FunctionScopes[idx])) 955 ThisExpr = captureThis(Context, RSI->TheRecordDecl, ThisTy, Loc); 956 957 bool isNested = NumClosures > 1; 958 CSI->addThisCapture(isNested, Loc, ThisTy, ThisExpr); 959 } 960 return false; 961} 962 963ExprResult Sema::ActOnCXXThis(SourceLocation Loc) { 964 /// C++ 9.3.2: In the body of a non-static member function, the keyword this 965 /// is a non-lvalue expression whose value is the address of the object for 966 /// which the function is called. 967 968 QualType ThisTy = getCurrentThisType(); 969 if (ThisTy.isNull()) return Diag(Loc, diag::err_invalid_this_use); 970 971 CheckCXXThisCapture(Loc); 972 return new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit=*/false); 973} 974 975bool Sema::isThisOutsideMemberFunctionBody(QualType BaseType) { 976 // If we're outside the body of a member function, then we'll have a specified 977 // type for 'this'. 978 if (CXXThisTypeOverride.isNull()) 979 return false; 980 981 // Determine whether we're looking into a class that's currently being 982 // defined. 983 CXXRecordDecl *Class = BaseType->getAsCXXRecordDecl(); 984 return Class && Class->isBeingDefined(); 985} 986 987ExprResult 988Sema::ActOnCXXTypeConstructExpr(ParsedType TypeRep, 989 SourceLocation LParenLoc, 990 MultiExprArg exprs, 991 SourceLocation RParenLoc) { 992 if (!TypeRep) 993 return ExprError(); 994 995 TypeSourceInfo *TInfo; 996 QualType Ty = GetTypeFromParser(TypeRep, &TInfo); 997 if (!TInfo) 998 TInfo = Context.getTrivialTypeSourceInfo(Ty, SourceLocation()); 999 1000 return BuildCXXTypeConstructExpr(TInfo, LParenLoc, exprs, RParenLoc); 1001} 1002 1003/// ActOnCXXTypeConstructExpr - Parse construction of a specified type. 1004/// Can be interpreted either as function-style casting ("int(x)") 1005/// or class type construction ("ClassType(x,y,z)") 1006/// or creation of a value-initialized type ("int()"). 1007ExprResult 1008Sema::BuildCXXTypeConstructExpr(TypeSourceInfo *TInfo, 1009 SourceLocation LParenLoc, 1010 MultiExprArg Exprs, 1011 SourceLocation RParenLoc) { 1012 QualType Ty = TInfo->getType(); 1013 SourceLocation TyBeginLoc = TInfo->getTypeLoc().getBeginLoc(); 1014 1015 if (Ty->isDependentType() || CallExpr::hasAnyTypeDependentArguments(Exprs)) { 1016 return CXXUnresolvedConstructExpr::Create(Context, TInfo, LParenLoc, Exprs, 1017 RParenLoc); 1018 } 1019 1020 bool ListInitialization = LParenLoc.isInvalid(); 1021 assert((!ListInitialization || (Exprs.size() == 1 && isa<InitListExpr>(Exprs[0]))) 1022 && "List initialization must have initializer list as expression."); 1023 SourceRange FullRange = SourceRange(TyBeginLoc, 1024 ListInitialization ? Exprs[0]->getSourceRange().getEnd() : RParenLoc); 1025 1026 // C++ [expr.type.conv]p1: 1027 // If the expression list is a single expression, the type conversion 1028 // expression is equivalent (in definedness, and if defined in meaning) to the 1029 // corresponding cast expression. 1030 if (Exprs.size() == 1 && !ListInitialization) { 1031 Expr *Arg = Exprs[0]; 1032 return BuildCXXFunctionalCastExpr(TInfo, LParenLoc, Arg, RParenLoc); 1033 } 1034 1035 QualType ElemTy = Ty; 1036 if (Ty->isArrayType()) { 1037 if (!ListInitialization) 1038 return ExprError(Diag(TyBeginLoc, 1039 diag::err_value_init_for_array_type) << FullRange); 1040 ElemTy = Context.getBaseElementType(Ty); 1041 } 1042 1043 if (!Ty->isVoidType() && 1044 RequireCompleteType(TyBeginLoc, ElemTy, 1045 diag::err_invalid_incomplete_type_use, FullRange)) 1046 return ExprError(); 1047 1048 if (RequireNonAbstractType(TyBeginLoc, Ty, 1049 diag::err_allocation_of_abstract_type)) 1050 return ExprError(); 1051 1052 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TInfo); 1053 InitializationKind Kind = 1054 Exprs.size() ? ListInitialization 1055 ? InitializationKind::CreateDirectList(TyBeginLoc) 1056 : InitializationKind::CreateDirect(TyBeginLoc, LParenLoc, RParenLoc) 1057 : InitializationKind::CreateValue(TyBeginLoc, LParenLoc, RParenLoc); 1058 InitializationSequence InitSeq(*this, Entity, Kind, Exprs); 1059 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Exprs); 1060 1061 if (Result.isInvalid() || !ListInitialization) 1062 return Result; 1063 1064 Expr *Inner = Result.get(); 1065 if (CXXBindTemporaryExpr *BTE = dyn_cast_or_null<CXXBindTemporaryExpr>(Inner)) 1066 Inner = BTE->getSubExpr(); 1067 if (!isa<CXXTemporaryObjectExpr>(Inner)) { 1068 // If we created a CXXTemporaryObjectExpr, that node also represents the 1069 // functional cast. Otherwise, create an explicit cast to represent 1070 // the syntactic form of a functional-style cast that was used here. 1071 // 1072 // FIXME: Creating a CXXFunctionalCastExpr around a CXXConstructExpr 1073 // would give a more consistent AST representation than using a 1074 // CXXTemporaryObjectExpr. It's also weird that the functional cast 1075 // is sometimes handled by initialization and sometimes not. 1076 QualType ResultType = Result.get()->getType(); 1077 Result = CXXFunctionalCastExpr::Create( 1078 Context, ResultType, Expr::getValueKindForType(TInfo->getType()), TInfo, 1079 CK_NoOp, Result.get(), /*Path=*/nullptr, LParenLoc, RParenLoc); 1080 } 1081 1082 return Result; 1083} 1084 1085/// doesUsualArrayDeleteWantSize - Answers whether the usual 1086/// operator delete[] for the given type has a size_t parameter. 1087static bool doesUsualArrayDeleteWantSize(Sema &S, SourceLocation loc, 1088 QualType allocType) { 1089 const RecordType *record = 1090 allocType->getBaseElementTypeUnsafe()->getAs<RecordType>(); 1091 if (!record) return false; 1092 1093 // Try to find an operator delete[] in class scope. 1094 1095 DeclarationName deleteName = 1096 S.Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete); 1097 LookupResult ops(S, deleteName, loc, Sema::LookupOrdinaryName); 1098 S.LookupQualifiedName(ops, record->getDecl()); 1099 1100 // We're just doing this for information. 1101 ops.suppressDiagnostics(); 1102 1103 // Very likely: there's no operator delete[]. 1104 if (ops.empty()) return false; 1105 1106 // If it's ambiguous, it should be illegal to call operator delete[] 1107 // on this thing, so it doesn't matter if we allocate extra space or not. 1108 if (ops.isAmbiguous()) return false; 1109 1110 LookupResult::Filter filter = ops.makeFilter(); 1111 while (filter.hasNext()) { 1112 NamedDecl *del = filter.next()->getUnderlyingDecl(); 1113 1114 // C++0x [basic.stc.dynamic.deallocation]p2: 1115 // A template instance is never a usual deallocation function, 1116 // regardless of its signature. 1117 if (isa<FunctionTemplateDecl>(del)) { 1118 filter.erase(); 1119 continue; 1120 } 1121 1122 // C++0x [basic.stc.dynamic.deallocation]p2: 1123 // If class T does not declare [an operator delete[] with one 1124 // parameter] but does declare a member deallocation function 1125 // named operator delete[] with exactly two parameters, the 1126 // second of which has type std::size_t, then this function 1127 // is a usual deallocation function. 1128 if (!cast<CXXMethodDecl>(del)->isUsualDeallocationFunction()) { 1129 filter.erase(); 1130 continue; 1131 } 1132 } 1133 filter.done(); 1134 1135 if (!ops.isSingleResult()) return false; 1136 1137 const FunctionDecl *del = cast<FunctionDecl>(ops.getFoundDecl()); 1138 return (del->getNumParams() == 2); 1139} 1140 1141/// \brief Parsed a C++ 'new' expression (C++ 5.3.4). 1142/// 1143/// E.g.: 1144/// @code new (memory) int[size][4] @endcode 1145/// or 1146/// @code ::new Foo(23, "hello") @endcode 1147/// 1148/// \param StartLoc The first location of the expression. 1149/// \param UseGlobal True if 'new' was prefixed with '::'. 1150/// \param PlacementLParen Opening paren of the placement arguments. 1151/// \param PlacementArgs Placement new arguments. 1152/// \param PlacementRParen Closing paren of the placement arguments. 1153/// \param TypeIdParens If the type is in parens, the source range. 1154/// \param D The type to be allocated, as well as array dimensions. 1155/// \param Initializer The initializing expression or initializer-list, or null 1156/// if there is none. 1157ExprResult 1158Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal, 1159 SourceLocation PlacementLParen, MultiExprArg PlacementArgs, 1160 SourceLocation PlacementRParen, SourceRange TypeIdParens, 1161 Declarator &D, Expr *Initializer) { 1162 bool TypeContainsAuto = D.getDeclSpec().containsPlaceholderType(); 1163 1164 Expr *ArraySize = nullptr; 1165 // If the specified type is an array, unwrap it and save the expression. 1166 if (D.getNumTypeObjects() > 0 && 1167 D.getTypeObject(0).Kind == DeclaratorChunk::Array) { 1168 DeclaratorChunk &Chunk = D.getTypeObject(0); 1169 if (TypeContainsAuto) 1170 return ExprError(Diag(Chunk.Loc, diag::err_new_array_of_auto) 1171 << D.getSourceRange()); 1172 if (Chunk.Arr.hasStatic) 1173 return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new) 1174 << D.getSourceRange()); 1175 if (!Chunk.Arr.NumElts) 1176 return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size) 1177 << D.getSourceRange()); 1178 1179 ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts); 1180 D.DropFirstTypeObject(); 1181 } 1182 1183 // Every dimension shall be of constant size. 1184 if (ArraySize) { 1185 for (unsigned I = 0, N = D.getNumTypeObjects(); I < N; ++I) { 1186 if (D.getTypeObject(I).Kind != DeclaratorChunk::Array) 1187 break; 1188 1189 DeclaratorChunk::ArrayTypeInfo &Array = D.getTypeObject(I).Arr; 1190 if (Expr *NumElts = (Expr *)Array.NumElts) { 1191 if (!NumElts->isTypeDependent() && !NumElts->isValueDependent()) { 1192 if (getLangOpts().CPlusPlus14) { 1193 // C++1y [expr.new]p6: Every constant-expression in a noptr-new-declarator 1194 // shall be a converted constant expression (5.19) of type std::size_t 1195 // and shall evaluate to a strictly positive value. 1196 unsigned IntWidth = Context.getTargetInfo().getIntWidth(); 1197 assert(IntWidth && "Builtin type of size 0?"); 1198 llvm::APSInt Value(IntWidth); 1199 Array.NumElts 1200 = CheckConvertedConstantExpression(NumElts, Context.getSizeType(), Value, 1201 CCEK_NewExpr) 1202 .get(); 1203 } else { 1204 Array.NumElts 1205 = VerifyIntegerConstantExpression(NumElts, nullptr, 1206 diag::err_new_array_nonconst) 1207 .get(); 1208 } 1209 if (!Array.NumElts) 1210 return ExprError(); 1211 } 1212 } 1213 } 1214 } 1215 1216 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, /*Scope=*/nullptr); 1217 QualType AllocType = TInfo->getType(); 1218 if (D.isInvalidType()) 1219 return ExprError(); 1220 1221 SourceRange DirectInitRange; 1222 if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) 1223 DirectInitRange = List->getSourceRange(); 1224 1225 return BuildCXXNew(SourceRange(StartLoc, D.getLocEnd()), UseGlobal, 1226 PlacementLParen, 1227 PlacementArgs, 1228 PlacementRParen, 1229 TypeIdParens, 1230 AllocType, 1231 TInfo, 1232 ArraySize, 1233 DirectInitRange, 1234 Initializer, 1235 TypeContainsAuto); 1236} 1237 1238static bool isLegalArrayNewInitializer(CXXNewExpr::InitializationStyle Style, 1239 Expr *Init) { 1240 if (!Init) 1241 return true; 1242 if (ParenListExpr *PLE = dyn_cast<ParenListExpr>(Init)) 1243 return PLE->getNumExprs() == 0; 1244 if (isa<ImplicitValueInitExpr>(Init)) 1245 return true; 1246 else if (CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init)) 1247 return !CCE->isListInitialization() && 1248 CCE->getConstructor()->isDefaultConstructor(); 1249 else if (Style == CXXNewExpr::ListInit) { 1250 assert(isa<InitListExpr>(Init) && 1251 "Shouldn't create list CXXConstructExprs for arrays."); 1252 return true; 1253 } 1254 return false; 1255} 1256 1257ExprResult 1258Sema::BuildCXXNew(SourceRange Range, bool UseGlobal, 1259 SourceLocation PlacementLParen, 1260 MultiExprArg PlacementArgs, 1261 SourceLocation PlacementRParen, 1262 SourceRange TypeIdParens, 1263 QualType AllocType, 1264 TypeSourceInfo *AllocTypeInfo, 1265 Expr *ArraySize, 1266 SourceRange DirectInitRange, 1267 Expr *Initializer, 1268 bool TypeMayContainAuto) { 1269 SourceRange TypeRange = AllocTypeInfo->getTypeLoc().getSourceRange(); 1270 SourceLocation StartLoc = Range.getBegin(); 1271 1272 CXXNewExpr::InitializationStyle initStyle; 1273 if (DirectInitRange.isValid()) { 1274 assert(Initializer && "Have parens but no initializer."); 1275 initStyle = CXXNewExpr::CallInit; 1276 } else if (Initializer && isa<InitListExpr>(Initializer)) 1277 initStyle = CXXNewExpr::ListInit; 1278 else { 1279 assert((!Initializer || isa<ImplicitValueInitExpr>(Initializer) || 1280 isa<CXXConstructExpr>(Initializer)) && 1281 "Initializer expression that cannot have been implicitly created."); 1282 initStyle = CXXNewExpr::NoInit; 1283 } 1284 1285 Expr **Inits = &Initializer; 1286 unsigned NumInits = Initializer ? 1 : 0; 1287 if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) { 1288 assert(initStyle == CXXNewExpr::CallInit && "paren init for non-call init"); 1289 Inits = List->getExprs(); 1290 NumInits = List->getNumExprs(); 1291 } 1292 1293 // C++11 [dcl.spec.auto]p6. Deduce the type which 'auto' stands in for. 1294 if (TypeMayContainAuto && AllocType->isUndeducedType()) { 1295 if (initStyle == CXXNewExpr::NoInit || NumInits == 0) 1296 return ExprError(Diag(StartLoc, diag::err_auto_new_requires_ctor_arg) 1297 << AllocType << TypeRange); 1298 if (initStyle == CXXNewExpr::ListInit || 1299 (NumInits == 1 && isa<InitListExpr>(Inits[0]))) 1300 return ExprError(Diag(Inits[0]->getLocStart(), 1301 diag::err_auto_new_list_init) 1302 << AllocType << TypeRange); 1303 if (NumInits > 1) { 1304 Expr *FirstBad = Inits[1]; 1305 return ExprError(Diag(FirstBad->getLocStart(), 1306 diag::err_auto_new_ctor_multiple_expressions) 1307 << AllocType << TypeRange); 1308 } 1309 Expr *Deduce = Inits[0]; 1310 QualType DeducedType; 1311 if (DeduceAutoType(AllocTypeInfo, Deduce, DeducedType) == DAR_Failed) 1312 return ExprError(Diag(StartLoc, diag::err_auto_new_deduction_failure) 1313 << AllocType << Deduce->getType() 1314 << TypeRange << Deduce->getSourceRange()); 1315 if (DeducedType.isNull()) 1316 return ExprError(); 1317 AllocType = DeducedType; 1318 } 1319 1320 // Per C++0x [expr.new]p5, the type being constructed may be a 1321 // typedef of an array type. 1322 if (!ArraySize) { 1323 if (const ConstantArrayType *Array 1324 = Context.getAsConstantArrayType(AllocType)) { 1325 ArraySize = IntegerLiteral::Create(Context, Array->getSize(), 1326 Context.getSizeType(), 1327 TypeRange.getEnd()); 1328 AllocType = Array->getElementType(); 1329 } 1330 } 1331 1332 if (CheckAllocatedType(AllocType, TypeRange.getBegin(), TypeRange)) 1333 return ExprError(); 1334 1335 if (initStyle == CXXNewExpr::ListInit && 1336 isStdInitializerList(AllocType, nullptr)) { 1337 Diag(AllocTypeInfo->getTypeLoc().getBeginLoc(), 1338 diag::warn_dangling_std_initializer_list) 1339 << /*at end of FE*/0 << Inits[0]->getSourceRange(); 1340 } 1341 1342 // In ARC, infer 'retaining' for the allocated 1343 if (getLangOpts().ObjCAutoRefCount && 1344 AllocType.getObjCLifetime() == Qualifiers::OCL_None && 1345 AllocType->isObjCLifetimeType()) { 1346 AllocType = Context.getLifetimeQualifiedType(AllocType, 1347 AllocType->getObjCARCImplicitLifetime()); 1348 } 1349 1350 QualType ResultType = Context.getPointerType(AllocType); 1351 1352 if (ArraySize && ArraySize->getType()->isNonOverloadPlaceholderType()) { 1353 ExprResult result = CheckPlaceholderExpr(ArraySize); 1354 if (result.isInvalid()) return ExprError(); 1355 ArraySize = result.get(); 1356 } 1357 // C++98 5.3.4p6: "The expression in a direct-new-declarator shall have 1358 // integral or enumeration type with a non-negative value." 1359 // C++11 [expr.new]p6: The expression [...] shall be of integral or unscoped 1360 // enumeration type, or a class type for which a single non-explicit 1361 // conversion function to integral or unscoped enumeration type exists. 1362 // C++1y [expr.new]p6: The expression [...] is implicitly converted to 1363 // std::size_t. 1364 if (ArraySize && !ArraySize->isTypeDependent()) { 1365 ExprResult ConvertedSize; 1366 if (getLangOpts().CPlusPlus14) { 1367 assert(Context.getTargetInfo().getIntWidth() && "Builtin type of size 0?"); 1368 1369 ConvertedSize = PerformImplicitConversion(ArraySize, Context.getSizeType(), 1370 AA_Converting); 1371 1372 if (!ConvertedSize.isInvalid() && 1373 ArraySize->getType()->getAs<RecordType>()) 1374 // Diagnose the compatibility of this conversion. 1375 Diag(StartLoc, diag::warn_cxx98_compat_array_size_conversion) 1376 << ArraySize->getType() << 0 << "'size_t'"; 1377 } else { 1378 class SizeConvertDiagnoser : public ICEConvertDiagnoser { 1379 protected: 1380 Expr *ArraySize; 1381 1382 public: 1383 SizeConvertDiagnoser(Expr *ArraySize) 1384 : ICEConvertDiagnoser(/*AllowScopedEnumerations*/false, false, false), 1385 ArraySize(ArraySize) {} 1386 1387 SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc, 1388 QualType T) override { 1389 return S.Diag(Loc, diag::err_array_size_not_integral) 1390 << S.getLangOpts().CPlusPlus11 << T; 1391 } 1392 1393 SemaDiagnosticBuilder diagnoseIncomplete( 1394 Sema &S, SourceLocation Loc, QualType T) override { 1395 return S.Diag(Loc, diag::err_array_size_incomplete_type) 1396 << T << ArraySize->getSourceRange(); 1397 } 1398 1399 SemaDiagnosticBuilder diagnoseExplicitConv( 1400 Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override { 1401 return S.Diag(Loc, diag::err_array_size_explicit_conversion) << T << ConvTy; 1402 } 1403 1404 SemaDiagnosticBuilder noteExplicitConv( 1405 Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override { 1406 return S.Diag(Conv->getLocation(), diag::note_array_size_conversion) 1407 << ConvTy->isEnumeralType() << ConvTy; 1408 } 1409 1410 SemaDiagnosticBuilder diagnoseAmbiguous( 1411 Sema &S, SourceLocation Loc, QualType T) override { 1412 return S.Diag(Loc, diag::err_array_size_ambiguous_conversion) << T; 1413 } 1414 1415 SemaDiagnosticBuilder noteAmbiguous( 1416 Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override { 1417 return S.Diag(Conv->getLocation(), diag::note_array_size_conversion) 1418 << ConvTy->isEnumeralType() << ConvTy; 1419 } 1420 1421 virtual SemaDiagnosticBuilder diagnoseConversion( 1422 Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override { 1423 return S.Diag(Loc, 1424 S.getLangOpts().CPlusPlus11 1425 ? diag::warn_cxx98_compat_array_size_conversion 1426 : diag::ext_array_size_conversion) 1427 << T << ConvTy->isEnumeralType() << ConvTy; 1428 } 1429 } SizeDiagnoser(ArraySize); 1430 1431 ConvertedSize = PerformContextualImplicitConversion(StartLoc, ArraySize, 1432 SizeDiagnoser); 1433 } 1434 if (ConvertedSize.isInvalid()) 1435 return ExprError(); 1436 1437 ArraySize = ConvertedSize.get(); 1438 QualType SizeType = ArraySize->getType(); 1439 1440 if (!SizeType->isIntegralOrUnscopedEnumerationType()) 1441 return ExprError(); 1442 1443 // C++98 [expr.new]p7: 1444 // The expression in a direct-new-declarator shall have integral type 1445 // with a non-negative value. 1446 // 1447 // Let's see if this is a constant < 0. If so, we reject it out of 1448 // hand. Otherwise, if it's not a constant, we must have an unparenthesized 1449 // array type. 1450 // 1451 // Note: such a construct has well-defined semantics in C++11: it throws 1452 // std::bad_array_new_length. 1453 if (!ArraySize->isValueDependent()) { 1454 llvm::APSInt Value; 1455 // We've already performed any required implicit conversion to integer or 1456 // unscoped enumeration type. 1457 if (ArraySize->isIntegerConstantExpr(Value, Context)) { 1458 if (Value < llvm::APSInt( 1459 llvm::APInt::getNullValue(Value.getBitWidth()), 1460 Value.isUnsigned())) { 1461 if (getLangOpts().CPlusPlus11) 1462 Diag(ArraySize->getLocStart(), 1463 diag::warn_typecheck_negative_array_new_size) 1464 << ArraySize->getSourceRange(); 1465 else 1466 return ExprError(Diag(ArraySize->getLocStart(), 1467 diag::err_typecheck_negative_array_size) 1468 << ArraySize->getSourceRange()); 1469 } else if (!AllocType->isDependentType()) { 1470 unsigned ActiveSizeBits = 1471 ConstantArrayType::getNumAddressingBits(Context, AllocType, Value); 1472 if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) { 1473 if (getLangOpts().CPlusPlus11) 1474 Diag(ArraySize->getLocStart(), 1475 diag::warn_array_new_too_large) 1476 << Value.toString(10) 1477 << ArraySize->getSourceRange(); 1478 else 1479 return ExprError(Diag(ArraySize->getLocStart(), 1480 diag::err_array_too_large) 1481 << Value.toString(10) 1482 << ArraySize->getSourceRange()); 1483 } 1484 } 1485 } else if (TypeIdParens.isValid()) { 1486 // Can't have dynamic array size when the type-id is in parentheses. 1487 Diag(ArraySize->getLocStart(), diag::ext_new_paren_array_nonconst) 1488 << ArraySize->getSourceRange() 1489 << FixItHint::CreateRemoval(TypeIdParens.getBegin()) 1490 << FixItHint::CreateRemoval(TypeIdParens.getEnd()); 1491 1492 TypeIdParens = SourceRange(); 1493 } 1494 } 1495 1496 // Note that we do *not* convert the argument in any way. It can 1497 // be signed, larger than size_t, whatever. 1498 } 1499 1500 FunctionDecl *OperatorNew = nullptr; 1501 FunctionDecl *OperatorDelete = nullptr; 1502 1503 if (!AllocType->isDependentType() && 1504 !Expr::hasAnyTypeDependentArguments(PlacementArgs) && 1505 FindAllocationFunctions(StartLoc, 1506 SourceRange(PlacementLParen, PlacementRParen), 1507 UseGlobal, AllocType, ArraySize, PlacementArgs, 1508 OperatorNew, OperatorDelete)) 1509 return ExprError(); 1510 1511 // If this is an array allocation, compute whether the usual array 1512 // deallocation function for the type has a size_t parameter. 1513 bool UsualArrayDeleteWantsSize = false; 1514 if (ArraySize && !AllocType->isDependentType()) 1515 UsualArrayDeleteWantsSize 1516 = doesUsualArrayDeleteWantSize(*this, StartLoc, AllocType); 1517 1518 SmallVector<Expr *, 8> AllPlaceArgs; 1519 if (OperatorNew) { 1520 const FunctionProtoType *Proto = 1521 OperatorNew->getType()->getAs<FunctionProtoType>(); 1522 VariadicCallType CallType = Proto->isVariadic() ? VariadicFunction 1523 : VariadicDoesNotApply; 1524 1525 // We've already converted the placement args, just fill in any default 1526 // arguments. Skip the first parameter because we don't have a corresponding 1527 // argument. 1528 if (GatherArgumentsForCall(PlacementLParen, OperatorNew, Proto, 1, 1529 PlacementArgs, AllPlaceArgs, CallType)) 1530 return ExprError(); 1531 1532 if (!AllPlaceArgs.empty()) 1533 PlacementArgs = AllPlaceArgs; 1534 1535 // FIXME: This is wrong: PlacementArgs misses out the first (size) argument. 1536 DiagnoseSentinelCalls(OperatorNew, PlacementLParen, PlacementArgs); 1537 1538 // FIXME: Missing call to CheckFunctionCall or equivalent 1539 } 1540 1541 // Warn if the type is over-aligned and is being allocated by global operator 1542 // new. 1543 if (PlacementArgs.empty() && OperatorNew && 1544 (OperatorNew->isImplicit() || 1545 getSourceManager().isInSystemHeader(OperatorNew->getLocStart()))) { 1546 if (unsigned Align = Context.getPreferredTypeAlign(AllocType.getTypePtr())){ 1547 unsigned SuitableAlign = Context.getTargetInfo().getSuitableAlign(); 1548 if (Align > SuitableAlign) 1549 Diag(StartLoc, diag::warn_overaligned_type) 1550 << AllocType 1551 << unsigned(Align / Context.getCharWidth()) 1552 << unsigned(SuitableAlign / Context.getCharWidth()); 1553 } 1554 } 1555 1556 QualType InitType = AllocType; 1557 // Array 'new' can't have any initializers except empty parentheses. 1558 // Initializer lists are also allowed, in C++11. Rely on the parser for the 1559 // dialect distinction. 1560 if (ResultType->isArrayType() || ArraySize) { 1561 if (!isLegalArrayNewInitializer(initStyle, Initializer)) { 1562 SourceRange InitRange(Inits[0]->getLocStart(), 1563 Inits[NumInits - 1]->getLocEnd()); 1564 Diag(StartLoc, diag::err_new_array_init_args) << InitRange; 1565 return ExprError(); 1566 } 1567 if (InitListExpr *ILE = dyn_cast_or_null<InitListExpr>(Initializer)) { 1568 // We do the initialization typechecking against the array type 1569 // corresponding to the number of initializers + 1 (to also check 1570 // default-initialization). 1571 unsigned NumElements = ILE->getNumInits() + 1; 1572 InitType = Context.getConstantArrayType(AllocType, 1573 llvm::APInt(Context.getTypeSize(Context.getSizeType()), NumElements), 1574 ArrayType::Normal, 0); 1575 } 1576 } 1577 1578 // If we can perform the initialization, and we've not already done so, 1579 // do it now. 1580 if (!AllocType->isDependentType() && 1581 !Expr::hasAnyTypeDependentArguments( 1582 llvm::makeArrayRef(Inits, NumInits))) { 1583 // C++11 [expr.new]p15: 1584 // A new-expression that creates an object of type T initializes that 1585 // object as follows: 1586 InitializationKind Kind 1587 // - If the new-initializer is omitted, the object is default- 1588 // initialized (8.5); if no initialization is performed, 1589 // the object has indeterminate value 1590 = initStyle == CXXNewExpr::NoInit 1591 ? InitializationKind::CreateDefault(TypeRange.getBegin()) 1592 // - Otherwise, the new-initializer is interpreted according to the 1593 // initialization rules of 8.5 for direct-initialization. 1594 : initStyle == CXXNewExpr::ListInit 1595 ? InitializationKind::CreateDirectList(TypeRange.getBegin()) 1596 : InitializationKind::CreateDirect(TypeRange.getBegin(), 1597 DirectInitRange.getBegin(), 1598 DirectInitRange.getEnd()); 1599 1600 InitializedEntity Entity 1601 = InitializedEntity::InitializeNew(StartLoc, InitType); 1602 InitializationSequence InitSeq(*this, Entity, Kind, MultiExprArg(Inits, NumInits)); 1603 ExprResult FullInit = InitSeq.Perform(*this, Entity, Kind, 1604 MultiExprArg(Inits, NumInits)); 1605 if (FullInit.isInvalid()) 1606 return ExprError(); 1607 1608 // FullInit is our initializer; strip off CXXBindTemporaryExprs, because 1609 // we don't want the initialized object to be destructed. 1610 if (CXXBindTemporaryExpr *Binder = 1611 dyn_cast_or_null<CXXBindTemporaryExpr>(FullInit.get())) 1612 FullInit = Binder->getSubExpr(); 1613 1614 Initializer = FullInit.get(); 1615 } 1616 1617 // Mark the new and delete operators as referenced. 1618 if (OperatorNew) { 1619 if (DiagnoseUseOfDecl(OperatorNew, StartLoc)) 1620 return ExprError(); 1621 MarkFunctionReferenced(StartLoc, OperatorNew); 1622 } 1623 if (OperatorDelete) { 1624 if (DiagnoseUseOfDecl(OperatorDelete, StartLoc)) 1625 return ExprError(); 1626 MarkFunctionReferenced(StartLoc, OperatorDelete); 1627 } 1628 1629 // C++0x [expr.new]p17: 1630 // If the new expression creates an array of objects of class type, 1631 // access and ambiguity control are done for the destructor. 1632 QualType BaseAllocType = Context.getBaseElementType(AllocType); 1633 if (ArraySize && !BaseAllocType->isDependentType()) { 1634 if (const RecordType *BaseRecordType = BaseAllocType->getAs<RecordType>()) { 1635 if (CXXDestructorDecl *dtor = LookupDestructor( 1636 cast<CXXRecordDecl>(BaseRecordType->getDecl()))) { 1637 MarkFunctionReferenced(StartLoc, dtor); 1638 CheckDestructorAccess(StartLoc, dtor, 1639 PDiag(diag::err_access_dtor) 1640 << BaseAllocType); 1641 if (DiagnoseUseOfDecl(dtor, StartLoc)) 1642 return ExprError(); 1643 } 1644 } 1645 } 1646 1647 return new (Context) 1648 CXXNewExpr(Context, UseGlobal, OperatorNew, OperatorDelete, 1649 UsualArrayDeleteWantsSize, PlacementArgs, TypeIdParens, 1650 ArraySize, initStyle, Initializer, ResultType, AllocTypeInfo, 1651 Range, DirectInitRange); 1652} 1653 1654/// \brief Checks that a type is suitable as the allocated type 1655/// in a new-expression. 1656bool Sema::CheckAllocatedType(QualType AllocType, SourceLocation Loc, 1657 SourceRange R) { 1658 // C++ 5.3.4p1: "[The] type shall be a complete object type, but not an 1659 // abstract class type or array thereof. 1660 if (AllocType->isFunctionType()) 1661 return Diag(Loc, diag::err_bad_new_type) 1662 << AllocType << 0 << R; 1663 else if (AllocType->isReferenceType()) 1664 return Diag(Loc, diag::err_bad_new_type) 1665 << AllocType << 1 << R; 1666 else if (!AllocType->isDependentType() && 1667 RequireCompleteType(Loc, AllocType, diag::err_new_incomplete_type,R)) 1668 return true; 1669 else if (RequireNonAbstractType(Loc, AllocType, 1670 diag::err_allocation_of_abstract_type)) 1671 return true; 1672 else if (AllocType->isVariablyModifiedType()) 1673 return Diag(Loc, diag::err_variably_modified_new_type) 1674 << AllocType; 1675 else if (unsigned AddressSpace = AllocType.getAddressSpace()) 1676 return Diag(Loc, diag::err_address_space_qualified_new) 1677 << AllocType.getUnqualifiedType() << AddressSpace; 1678 else if (getLangOpts().ObjCAutoRefCount) { 1679 if (const ArrayType *AT = Context.getAsArrayType(AllocType)) { 1680 QualType BaseAllocType = Context.getBaseElementType(AT); 1681 if (BaseAllocType.getObjCLifetime() == Qualifiers::OCL_None && 1682 BaseAllocType->isObjCLifetimeType()) 1683 return Diag(Loc, diag::err_arc_new_array_without_ownership) 1684 << BaseAllocType; 1685 } 1686 } 1687 1688 return false; 1689} 1690 1691/// \brief Determine whether the given function is a non-placement 1692/// deallocation function. 1693static bool isNonPlacementDeallocationFunction(Sema &S, FunctionDecl *FD) { 1694 if (FD->isInvalidDecl()) 1695 return false; 1696 1697 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD)) 1698 return Method->isUsualDeallocationFunction(); 1699 1700 if (FD->getOverloadedOperator() != OO_Delete && 1701 FD->getOverloadedOperator() != OO_Array_Delete) 1702 return false; 1703 1704 if (FD->getNumParams() == 1) 1705 return true; 1706 1707 return S.getLangOpts().SizedDeallocation && FD->getNumParams() == 2 && 1708 S.Context.hasSameUnqualifiedType(FD->getParamDecl(1)->getType(), 1709 S.Context.getSizeType()); 1710} 1711 1712/// FindAllocationFunctions - Finds the overloads of operator new and delete 1713/// that are appropriate for the allocation. 1714bool Sema::FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range, 1715 bool UseGlobal, QualType AllocType, 1716 bool IsArray, MultiExprArg PlaceArgs, 1717 FunctionDecl *&OperatorNew, 1718 FunctionDecl *&OperatorDelete) { 1719 // --- Choosing an allocation function --- 1720 // C++ 5.3.4p8 - 14 & 18 1721 // 1) If UseGlobal is true, only look in the global scope. Else, also look 1722 // in the scope of the allocated class. 1723 // 2) If an array size is given, look for operator new[], else look for 1724 // operator new. 1725 // 3) The first argument is always size_t. Append the arguments from the 1726 // placement form. 1727 1728 SmallVector<Expr*, 8> AllocArgs(1 + PlaceArgs.size()); 1729 // We don't care about the actual value of this argument. 1730 // FIXME: Should the Sema create the expression and embed it in the syntax 1731 // tree? Or should the consumer just recalculate the value? 1732 IntegerLiteral Size(Context, llvm::APInt::getNullValue( 1733 Context.getTargetInfo().getPointerWidth(0)), 1734 Context.getSizeType(), 1735 SourceLocation()); 1736 AllocArgs[0] = &Size; 1737 std::copy(PlaceArgs.begin(), PlaceArgs.end(), AllocArgs.begin() + 1); 1738 1739 // C++ [expr.new]p8: 1740 // If the allocated type is a non-array type, the allocation 1741 // function's name is operator new and the deallocation function's 1742 // name is operator delete. If the allocated type is an array 1743 // type, the allocation function's name is operator new[] and the 1744 // deallocation function's name is operator delete[]. 1745 DeclarationName NewName = Context.DeclarationNames.getCXXOperatorName( 1746 IsArray ? OO_Array_New : OO_New); 1747 DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName( 1748 IsArray ? OO_Array_Delete : OO_Delete); 1749 1750 QualType AllocElemType = Context.getBaseElementType(AllocType); 1751 1752 if (AllocElemType->isRecordType() && !UseGlobal) { 1753 CXXRecordDecl *Record 1754 = cast<CXXRecordDecl>(AllocElemType->getAs<RecordType>()->getDecl()); 1755 if (FindAllocationOverload(StartLoc, Range, NewName, AllocArgs, Record, 1756 /*AllowMissing=*/true, OperatorNew)) 1757 return true; 1758 } 1759 1760 if (!OperatorNew) { 1761 // Didn't find a member overload. Look for a global one. 1762 DeclareGlobalNewDelete(); 1763 DeclContext *TUDecl = Context.getTranslationUnitDecl(); 1764 bool FallbackEnabled = IsArray && Context.getLangOpts().MSVCCompat; 1765 if (FindAllocationOverload(StartLoc, Range, NewName, AllocArgs, TUDecl, 1766 /*AllowMissing=*/FallbackEnabled, OperatorNew, 1767 /*Diagnose=*/!FallbackEnabled)) { 1768 if (!FallbackEnabled) 1769 return true; 1770 1771 // MSVC will fall back on trying to find a matching global operator new 1772 // if operator new[] cannot be found. Also, MSVC will leak by not 1773 // generating a call to operator delete or operator delete[], but we 1774 // will not replicate that bug. 1775 NewName = Context.DeclarationNames.getCXXOperatorName(OO_New); 1776 DeleteName = Context.DeclarationNames.getCXXOperatorName(OO_Delete); 1777 if (FindAllocationOverload(StartLoc, Range, NewName, AllocArgs, TUDecl, 1778 /*AllowMissing=*/false, OperatorNew)) 1779 return true; 1780 } 1781 } 1782 1783 // We don't need an operator delete if we're running under 1784 // -fno-exceptions. 1785 if (!getLangOpts().Exceptions) { 1786 OperatorDelete = nullptr; 1787 return false; 1788 } 1789 1790 // C++ [expr.new]p19: 1791 // 1792 // If the new-expression begins with a unary :: operator, the 1793 // deallocation function's name is looked up in the global 1794 // scope. Otherwise, if the allocated type is a class type T or an 1795 // array thereof, the deallocation function's name is looked up in 1796 // the scope of T. If this lookup fails to find the name, or if 1797 // the allocated type is not a class type or array thereof, the 1798 // deallocation function's name is looked up in the global scope. 1799 LookupResult FoundDelete(*this, DeleteName, StartLoc, LookupOrdinaryName); 1800 if (AllocElemType->isRecordType() && !UseGlobal) { 1801 CXXRecordDecl *RD 1802 = cast<CXXRecordDecl>(AllocElemType->getAs<RecordType>()->getDecl()); 1803 LookupQualifiedName(FoundDelete, RD); 1804 } 1805 if (FoundDelete.isAmbiguous()) 1806 return true; // FIXME: clean up expressions? 1807 1808 if (FoundDelete.empty()) { 1809 DeclareGlobalNewDelete(); 1810 LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl()); 1811 } 1812 1813 FoundDelete.suppressDiagnostics(); 1814 1815 SmallVector<std::pair<DeclAccessPair,FunctionDecl*>, 2> Matches; 1816 1817 // Whether we're looking for a placement operator delete is dictated 1818 // by whether we selected a placement operator new, not by whether 1819 // we had explicit placement arguments. This matters for things like 1820 // struct A { void *operator new(size_t, int = 0); ... }; 1821 // A *a = new A() 1822 bool isPlacementNew = (!PlaceArgs.empty() || OperatorNew->param_size() != 1); 1823 1824 if (isPlacementNew) { 1825 // C++ [expr.new]p20: 1826 // A declaration of a placement deallocation function matches the 1827 // declaration of a placement allocation function if it has the 1828 // same number of parameters and, after parameter transformations 1829 // (8.3.5), all parameter types except the first are 1830 // identical. [...] 1831 // 1832 // To perform this comparison, we compute the function type that 1833 // the deallocation function should have, and use that type both 1834 // for template argument deduction and for comparison purposes. 1835 // 1836 // FIXME: this comparison should ignore CC and the like. 1837 QualType ExpectedFunctionType; 1838 { 1839 const FunctionProtoType *Proto 1840 = OperatorNew->getType()->getAs<FunctionProtoType>(); 1841 1842 SmallVector<QualType, 4> ArgTypes; 1843 ArgTypes.push_back(Context.VoidPtrTy); 1844 for (unsigned I = 1, N = Proto->getNumParams(); I < N; ++I) 1845 ArgTypes.push_back(Proto->getParamType(I)); 1846 1847 FunctionProtoType::ExtProtoInfo EPI; 1848 EPI.Variadic = Proto->isVariadic(); 1849 1850 ExpectedFunctionType 1851 = Context.getFunctionType(Context.VoidTy, ArgTypes, EPI); 1852 } 1853 1854 for (LookupResult::iterator D = FoundDelete.begin(), 1855 DEnd = FoundDelete.end(); 1856 D != DEnd; ++D) { 1857 FunctionDecl *Fn = nullptr; 1858 if (FunctionTemplateDecl *FnTmpl 1859 = dyn_cast<FunctionTemplateDecl>((*D)->getUnderlyingDecl())) { 1860 // Perform template argument deduction to try to match the 1861 // expected function type. 1862 TemplateDeductionInfo Info(StartLoc); 1863 if (DeduceTemplateArguments(FnTmpl, nullptr, ExpectedFunctionType, Fn, 1864 Info)) 1865 continue; 1866 } else 1867 Fn = cast<FunctionDecl>((*D)->getUnderlyingDecl()); 1868 1869 if (Context.hasSameType(Fn->getType(), ExpectedFunctionType)) 1870 Matches.push_back(std::make_pair(D.getPair(), Fn)); 1871 } 1872 } else { 1873 // C++ [expr.new]p20: 1874 // [...] Any non-placement deallocation function matches a 1875 // non-placement allocation function. [...] 1876 for (LookupResult::iterator D = FoundDelete.begin(), 1877 DEnd = FoundDelete.end(); 1878 D != DEnd; ++D) { 1879 if (FunctionDecl *Fn = dyn_cast<FunctionDecl>((*D)->getUnderlyingDecl())) 1880 if (isNonPlacementDeallocationFunction(*this, Fn)) 1881 Matches.push_back(std::make_pair(D.getPair(), Fn)); 1882 } 1883 1884 // C++1y [expr.new]p22: 1885 // For a non-placement allocation function, the normal deallocation 1886 // function lookup is used 1887 // C++1y [expr.delete]p?: 1888 // If [...] deallocation function lookup finds both a usual deallocation 1889 // function with only a pointer parameter and a usual deallocation 1890 // function with both a pointer parameter and a size parameter, then the 1891 // selected deallocation function shall be the one with two parameters. 1892 // Otherwise, the selected deallocation function shall be the function 1893 // with one parameter. 1894 if (getLangOpts().SizedDeallocation && Matches.size() == 2) { 1895 if (Matches[0].second->getNumParams() == 1) 1896 Matches.erase(Matches.begin()); 1897 else 1898 Matches.erase(Matches.begin() + 1); 1899 assert(Matches[0].second->getNumParams() == 2 && 1900 "found an unexpected usual deallocation function"); 1901 } 1902 } 1903 1904 // C++ [expr.new]p20: 1905 // [...] If the lookup finds a single matching deallocation 1906 // function, that function will be called; otherwise, no 1907 // deallocation function will be called. 1908 if (Matches.size() == 1) { 1909 OperatorDelete = Matches[0].second; 1910 1911 // C++0x [expr.new]p20: 1912 // If the lookup finds the two-parameter form of a usual 1913 // deallocation function (3.7.4.2) and that function, considered 1914 // as a placement deallocation function, would have been 1915 // selected as a match for the allocation function, the program 1916 // is ill-formed. 1917 if (!PlaceArgs.empty() && getLangOpts().CPlusPlus11 && 1918 isNonPlacementDeallocationFunction(*this, OperatorDelete)) { 1919 Diag(StartLoc, diag::err_placement_new_non_placement_delete) 1920 << SourceRange(PlaceArgs.front()->getLocStart(), 1921 PlaceArgs.back()->getLocEnd()); 1922 if (!OperatorDelete->isImplicit()) 1923 Diag(OperatorDelete->getLocation(), diag::note_previous_decl) 1924 << DeleteName; 1925 } else { 1926 CheckAllocationAccess(StartLoc, Range, FoundDelete.getNamingClass(), 1927 Matches[0].first); 1928 } 1929 } 1930 1931 return false; 1932} 1933 1934/// \brief Find an fitting overload for the allocation function 1935/// in the specified scope. 1936/// 1937/// \param StartLoc The location of the 'new' token. 1938/// \param Range The range of the placement arguments. 1939/// \param Name The name of the function ('operator new' or 'operator new[]'). 1940/// \param Args The placement arguments specified. 1941/// \param Ctx The scope in which we should search; either a class scope or the 1942/// translation unit. 1943/// \param AllowMissing If \c true, report an error if we can't find any 1944/// allocation functions. Otherwise, succeed but don't fill in \p 1945/// Operator. 1946/// \param Operator Filled in with the found allocation function. Unchanged if 1947/// no allocation function was found. 1948/// \param Diagnose If \c true, issue errors if the allocation function is not 1949/// usable. 1950bool Sema::FindAllocationOverload(SourceLocation StartLoc, SourceRange Range, 1951 DeclarationName Name, MultiExprArg Args, 1952 DeclContext *Ctx, 1953 bool AllowMissing, FunctionDecl *&Operator, 1954 bool Diagnose) { 1955 LookupResult R(*this, Name, StartLoc, LookupOrdinaryName); 1956 LookupQualifiedName(R, Ctx); 1957 if (R.empty()) { 1958 if (AllowMissing || !Diagnose) 1959 return false; 1960 return Diag(StartLoc, diag::err_ovl_no_viable_function_in_call) 1961 << Name << Range; 1962 } 1963 1964 if (R.isAmbiguous()) 1965 return true; 1966 1967 R.suppressDiagnostics(); 1968 1969 OverloadCandidateSet Candidates(StartLoc, OverloadCandidateSet::CSK_Normal); 1970 for (LookupResult::iterator Alloc = R.begin(), AllocEnd = R.end(); 1971 Alloc != AllocEnd; ++Alloc) { 1972 // Even member operator new/delete are implicitly treated as 1973 // static, so don't use AddMemberCandidate. 1974 NamedDecl *D = (*Alloc)->getUnderlyingDecl(); 1975 1976 if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) { 1977 AddTemplateOverloadCandidate(FnTemplate, Alloc.getPair(), 1978 /*ExplicitTemplateArgs=*/nullptr, 1979 Args, Candidates, 1980 /*SuppressUserConversions=*/false); 1981 continue; 1982 } 1983 1984 FunctionDecl *Fn = cast<FunctionDecl>(D); 1985 AddOverloadCandidate(Fn, Alloc.getPair(), Args, Candidates, 1986 /*SuppressUserConversions=*/false); 1987 } 1988 1989 // Do the resolution. 1990 OverloadCandidateSet::iterator Best; 1991 switch (Candidates.BestViableFunction(*this, StartLoc, Best)) { 1992 case OR_Success: { 1993 // Got one! 1994 FunctionDecl *FnDecl = Best->Function; 1995 if (CheckAllocationAccess(StartLoc, Range, R.getNamingClass(), 1996 Best->FoundDecl, Diagnose) == AR_inaccessible) 1997 return true; 1998 1999 Operator = FnDecl; 2000 return false; 2001 } 2002 2003 case OR_No_Viable_Function: 2004 if (Diagnose) { 2005 Diag(StartLoc, diag::err_ovl_no_viable_function_in_call) 2006 << Name << Range; 2007 Candidates.NoteCandidates(*this, OCD_AllCandidates, Args); 2008 } 2009 return true; 2010 2011 case OR_Ambiguous: 2012 if (Diagnose) { 2013 Diag(StartLoc, diag::err_ovl_ambiguous_call) 2014 << Name << Range; 2015 Candidates.NoteCandidates(*this, OCD_ViableCandidates, Args); 2016 } 2017 return true; 2018 2019 case OR_Deleted: { 2020 if (Diagnose) { 2021 Diag(StartLoc, diag::err_ovl_deleted_call) 2022 << Best->Function->isDeleted() 2023 << Name 2024 << getDeletedOrUnavailableSuffix(Best->Function) 2025 << Range; 2026 Candidates.NoteCandidates(*this, OCD_AllCandidates, Args); 2027 } 2028 return true; 2029 } 2030 } 2031 llvm_unreachable("Unreachable, bad result from BestViableFunction"); 2032} 2033 2034 2035/// DeclareGlobalNewDelete - Declare the global forms of operator new and 2036/// delete. These are: 2037/// @code 2038/// // C++03: 2039/// void* operator new(std::size_t) throw(std::bad_alloc); 2040/// void* operator new[](std::size_t) throw(std::bad_alloc); 2041/// void operator delete(void *) throw(); 2042/// void operator delete[](void *) throw(); 2043/// // C++11: 2044/// void* operator new(std::size_t); 2045/// void* operator new[](std::size_t); 2046/// void operator delete(void *) noexcept; 2047/// void operator delete[](void *) noexcept; 2048/// // C++1y: 2049/// void* operator new(std::size_t); 2050/// void* operator new[](std::size_t); 2051/// void operator delete(void *) noexcept; 2052/// void operator delete[](void *) noexcept; 2053/// void operator delete(void *, std::size_t) noexcept; 2054/// void operator delete[](void *, std::size_t) noexcept; 2055/// @endcode 2056/// Note that the placement and nothrow forms of new are *not* implicitly 2057/// declared. Their use requires including \<new\>. 2058void Sema::DeclareGlobalNewDelete() { 2059 if (GlobalNewDeleteDeclared) 2060 return; 2061 2062 // C++ [basic.std.dynamic]p2: 2063 // [...] The following allocation and deallocation functions (18.4) are 2064 // implicitly declared in global scope in each translation unit of a 2065 // program 2066 // 2067 // C++03: 2068 // void* operator new(std::size_t) throw(std::bad_alloc); 2069 // void* operator new[](std::size_t) throw(std::bad_alloc); 2070 // void operator delete(void*) throw(); 2071 // void operator delete[](void*) throw(); 2072 // C++11: 2073 // void* operator new(std::size_t); 2074 // void* operator new[](std::size_t); 2075 // void operator delete(void*) noexcept; 2076 // void operator delete[](void*) noexcept; 2077 // C++1y: 2078 // void* operator new(std::size_t); 2079 // void* operator new[](std::size_t); 2080 // void operator delete(void*) noexcept; 2081 // void operator delete[](void*) noexcept; 2082 // void operator delete(void*, std::size_t) noexcept; 2083 // void operator delete[](void*, std::size_t) noexcept; 2084 // 2085 // These implicit declarations introduce only the function names operator 2086 // new, operator new[], operator delete, operator delete[]. 2087 // 2088 // Here, we need to refer to std::bad_alloc, so we will implicitly declare 2089 // "std" or "bad_alloc" as necessary to form the exception specification. 2090 // However, we do not make these implicit declarations visible to name 2091 // lookup. 2092 if (!StdBadAlloc && !getLangOpts().CPlusPlus11) { 2093 // The "std::bad_alloc" class has not yet been declared, so build it 2094 // implicitly. 2095 StdBadAlloc = CXXRecordDecl::Create(Context, TTK_Class, 2096 getOrCreateStdNamespace(), 2097 SourceLocation(), SourceLocation(), 2098 &PP.getIdentifierTable().get("bad_alloc"), 2099 nullptr); 2100 getStdBadAlloc()->setImplicit(true); 2101 } 2102 2103 GlobalNewDeleteDeclared = true; 2104 2105 QualType VoidPtr = Context.getPointerType(Context.VoidTy); 2106 QualType SizeT = Context.getSizeType(); 2107 bool AssumeSaneOperatorNew = getLangOpts().AssumeSaneOperatorNew; 2108 2109 DeclareGlobalAllocationFunction( 2110 Context.DeclarationNames.getCXXOperatorName(OO_New), 2111 VoidPtr, SizeT, QualType(), AssumeSaneOperatorNew); 2112 DeclareGlobalAllocationFunction( 2113 Context.DeclarationNames.getCXXOperatorName(OO_Array_New), 2114 VoidPtr, SizeT, QualType(), AssumeSaneOperatorNew); 2115 DeclareGlobalAllocationFunction( 2116 Context.DeclarationNames.getCXXOperatorName(OO_Delete), 2117 Context.VoidTy, VoidPtr); 2118 DeclareGlobalAllocationFunction( 2119 Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete), 2120 Context.VoidTy, VoidPtr); 2121 if (getLangOpts().SizedDeallocation) { 2122 DeclareGlobalAllocationFunction( 2123 Context.DeclarationNames.getCXXOperatorName(OO_Delete), 2124 Context.VoidTy, VoidPtr, Context.getSizeType()); 2125 DeclareGlobalAllocationFunction( 2126 Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete), 2127 Context.VoidTy, VoidPtr, Context.getSizeType()); 2128 } 2129} 2130 2131/// DeclareGlobalAllocationFunction - Declares a single implicit global 2132/// allocation function if it doesn't already exist. 2133void Sema::DeclareGlobalAllocationFunction(DeclarationName Name, 2134 QualType Return, 2135 QualType Param1, QualType Param2, 2136 bool AddRestrictAttr) { 2137 DeclContext *GlobalCtx = Context.getTranslationUnitDecl(); 2138 unsigned NumParams = Param2.isNull() ? 1 : 2; 2139 2140 // Check if this function is already declared. 2141 DeclContext::lookup_result R = GlobalCtx->lookup(Name); 2142 for (DeclContext::lookup_iterator Alloc = R.begin(), AllocEnd = R.end(); 2143 Alloc != AllocEnd; ++Alloc) { 2144 // Only look at non-template functions, as it is the predefined, 2145 // non-templated allocation function we are trying to declare here. 2146 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(*Alloc)) { 2147 if (Func->getNumParams() == NumParams) { 2148 QualType InitialParam1Type = 2149 Context.getCanonicalType(Func->getParamDecl(0) 2150 ->getType().getUnqualifiedType()); 2151 QualType InitialParam2Type = 2152 NumParams == 2 2153 ? Context.getCanonicalType(Func->getParamDecl(1) 2154 ->getType().getUnqualifiedType()) 2155 : QualType(); 2156 // FIXME: Do we need to check for default arguments here? 2157 if (InitialParam1Type == Param1 && 2158 (NumParams == 1 || InitialParam2Type == Param2)) { 2159 if (AddRestrictAttr && !Func->hasAttr<RestrictAttr>()) 2160 Func->addAttr(RestrictAttr::CreateImplicit( 2161 Context, RestrictAttr::GNU_malloc)); 2162 // Make the function visible to name lookup, even if we found it in 2163 // an unimported module. It either is an implicitly-declared global 2164 // allocation function, or is suppressing that function. 2165 Func->setHidden(false); 2166 return; 2167 } 2168 } 2169 } 2170 } 2171 2172 FunctionProtoType::ExtProtoInfo EPI; 2173 2174 QualType BadAllocType; 2175 bool HasBadAllocExceptionSpec 2176 = (Name.getCXXOverloadedOperator() == OO_New || 2177 Name.getCXXOverloadedOperator() == OO_Array_New); 2178 if (HasBadAllocExceptionSpec) { 2179 if (!getLangOpts().CPlusPlus11) { 2180 BadAllocType = Context.getTypeDeclType(getStdBadAlloc()); 2181 assert(StdBadAlloc && "Must have std::bad_alloc declared"); 2182 EPI.ExceptionSpec.Type = EST_Dynamic; 2183 EPI.ExceptionSpec.Exceptions = llvm::makeArrayRef(BadAllocType); 2184 } 2185 } else { 2186 EPI.ExceptionSpec = 2187 getLangOpts().CPlusPlus11 ? EST_BasicNoexcept : EST_DynamicNone; 2188 } 2189 2190 QualType Params[] = { Param1, Param2 }; 2191 2192 QualType FnType = Context.getFunctionType( 2193 Return, llvm::makeArrayRef(Params, NumParams), EPI); 2194 FunctionDecl *Alloc = 2195 FunctionDecl::Create(Context, GlobalCtx, SourceLocation(), 2196 SourceLocation(), Name, 2197 FnType, /*TInfo=*/nullptr, SC_None, false, true); 2198 Alloc->setImplicit(); 2199 2200 // Implicit sized deallocation functions always have default visibility. 2201 Alloc->addAttr(VisibilityAttr::CreateImplicit(Context, 2202 VisibilityAttr::Default)); 2203 2204 if (AddRestrictAttr) 2205 Alloc->addAttr( 2206 RestrictAttr::CreateImplicit(Context, RestrictAttr::GNU_malloc)); 2207 2208 ParmVarDecl *ParamDecls[2]; 2209 for (unsigned I = 0; I != NumParams; ++I) { 2210 ParamDecls[I] = ParmVarDecl::Create(Context, Alloc, SourceLocation(), 2211 SourceLocation(), nullptr, 2212 Params[I], /*TInfo=*/nullptr, 2213 SC_None, nullptr); 2214 ParamDecls[I]->setImplicit(); 2215 } 2216 Alloc->setParams(llvm::makeArrayRef(ParamDecls, NumParams)); 2217 2218 Context.getTranslationUnitDecl()->addDecl(Alloc); 2219 IdResolver.tryAddTopLevelDecl(Alloc, Name); 2220} 2221 2222FunctionDecl *Sema::FindUsualDeallocationFunction(SourceLocation StartLoc, 2223 bool CanProvideSize, 2224 DeclarationName Name) { 2225 DeclareGlobalNewDelete(); 2226 2227 LookupResult FoundDelete(*this, Name, StartLoc, LookupOrdinaryName); 2228 LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl()); 2229 2230 // C++ [expr.new]p20: 2231 // [...] Any non-placement deallocation function matches a 2232 // non-placement allocation function. [...] 2233 llvm::SmallVector<FunctionDecl*, 2> Matches; 2234 for (LookupResult::iterator D = FoundDelete.begin(), 2235 DEnd = FoundDelete.end(); 2236 D != DEnd; ++D) { 2237 if (FunctionDecl *Fn = dyn_cast<FunctionDecl>(*D)) 2238 if (isNonPlacementDeallocationFunction(*this, Fn)) 2239 Matches.push_back(Fn); 2240 } 2241 2242 // C++1y [expr.delete]p?: 2243 // If the type is complete and deallocation function lookup finds both a 2244 // usual deallocation function with only a pointer parameter and a usual 2245 // deallocation function with both a pointer parameter and a size 2246 // parameter, then the selected deallocation function shall be the one 2247 // with two parameters. Otherwise, the selected deallocation function 2248 // shall be the function with one parameter. 2249 if (getLangOpts().SizedDeallocation && Matches.size() == 2) { 2250 unsigned NumArgs = CanProvideSize ? 2 : 1; 2251 if (Matches[0]->getNumParams() != NumArgs) 2252 Matches.erase(Matches.begin()); 2253 else 2254 Matches.erase(Matches.begin() + 1); 2255 assert(Matches[0]->getNumParams() == NumArgs && 2256 "found an unexpected usual deallocation function"); 2257 } 2258 2259 assert(Matches.size() == 1 && 2260 "unexpectedly have multiple usual deallocation functions"); 2261 return Matches.front(); 2262} 2263 2264bool Sema::FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD, 2265 DeclarationName Name, 2266 FunctionDecl* &Operator, bool Diagnose) { 2267 LookupResult Found(*this, Name, StartLoc, LookupOrdinaryName); 2268 // Try to find operator delete/operator delete[] in class scope. 2269 LookupQualifiedName(Found, RD); 2270 2271 if (Found.isAmbiguous()) 2272 return true; 2273 2274 Found.suppressDiagnostics(); 2275 2276 SmallVector<DeclAccessPair,4> Matches; 2277 for (LookupResult::iterator F = Found.begin(), FEnd = Found.end(); 2278 F != FEnd; ++F) { 2279 NamedDecl *ND = (*F)->getUnderlyingDecl(); 2280 2281 // Ignore template operator delete members from the check for a usual 2282 // deallocation function. 2283 if (isa<FunctionTemplateDecl>(ND)) 2284 continue; 2285 2286 if (cast<CXXMethodDecl>(ND)->isUsualDeallocationFunction()) 2287 Matches.push_back(F.getPair()); 2288 } 2289 2290 // There's exactly one suitable operator; pick it. 2291 if (Matches.size() == 1) { 2292 Operator = cast<CXXMethodDecl>(Matches[0]->getUnderlyingDecl()); 2293 2294 if (Operator->isDeleted()) { 2295 if (Diagnose) { 2296 Diag(StartLoc, diag::err_deleted_function_use); 2297 NoteDeletedFunction(Operator); 2298 } 2299 return true; 2300 } 2301 2302 if (CheckAllocationAccess(StartLoc, SourceRange(), Found.getNamingClass(), 2303 Matches[0], Diagnose) == AR_inaccessible) 2304 return true; 2305 2306 return false; 2307 2308 // We found multiple suitable operators; complain about the ambiguity. 2309 } else if (!Matches.empty()) { 2310 if (Diagnose) { 2311 Diag(StartLoc, diag::err_ambiguous_suitable_delete_member_function_found) 2312 << Name << RD; 2313 2314 for (SmallVectorImpl<DeclAccessPair>::iterator 2315 F = Matches.begin(), FEnd = Matches.end(); F != FEnd; ++F) 2316 Diag((*F)->getUnderlyingDecl()->getLocation(), 2317 diag::note_member_declared_here) << Name; 2318 } 2319 return true; 2320 } 2321 2322 // We did find operator delete/operator delete[] declarations, but 2323 // none of them were suitable. 2324 if (!Found.empty()) { 2325 if (Diagnose) { 2326 Diag(StartLoc, diag::err_no_suitable_delete_member_function_found) 2327 << Name << RD; 2328 2329 for (LookupResult::iterator F = Found.begin(), FEnd = Found.end(); 2330 F != FEnd; ++F) 2331 Diag((*F)->getUnderlyingDecl()->getLocation(), 2332 diag::note_member_declared_here) << Name; 2333 } 2334 return true; 2335 } 2336 2337 Operator = nullptr; 2338 return false; 2339} 2340 2341/// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in: 2342/// @code ::delete ptr; @endcode 2343/// or 2344/// @code delete [] ptr; @endcode 2345ExprResult 2346Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal, 2347 bool ArrayForm, Expr *ExE) { 2348 // C++ [expr.delete]p1: 2349 // The operand shall have a pointer type, or a class type having a single 2350 // non-explicit conversion function to a pointer type. The result has type 2351 // void. 2352 // 2353 // DR599 amends "pointer type" to "pointer to object type" in both cases. 2354 2355 ExprResult Ex = ExE; 2356 FunctionDecl *OperatorDelete = nullptr; 2357 bool ArrayFormAsWritten = ArrayForm; 2358 bool UsualArrayDeleteWantsSize = false; 2359 2360 if (!Ex.get()->isTypeDependent()) { 2361 // Perform lvalue-to-rvalue cast, if needed. 2362 Ex = DefaultLvalueConversion(Ex.get()); 2363 if (Ex.isInvalid()) 2364 return ExprError(); 2365 2366 QualType Type = Ex.get()->getType(); 2367 2368 class DeleteConverter : public ContextualImplicitConverter { 2369 public: 2370 DeleteConverter() : ContextualImplicitConverter(false, true) {} 2371 2372 bool match(QualType ConvType) override { 2373 // FIXME: If we have an operator T* and an operator void*, we must pick 2374 // the operator T*. 2375 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 2376 if (ConvPtrType->getPointeeType()->isIncompleteOrObjectType()) 2377 return true; 2378 return false; 2379 } 2380 2381 SemaDiagnosticBuilder diagnoseNoMatch(Sema &S, SourceLocation Loc, 2382 QualType T) override { 2383 return S.Diag(Loc, diag::err_delete_operand) << T; 2384 } 2385 2386 SemaDiagnosticBuilder diagnoseIncomplete(Sema &S, SourceLocation Loc, 2387 QualType T) override { 2388 return S.Diag(Loc, diag::err_delete_incomplete_class_type) << T; 2389 } 2390 2391 SemaDiagnosticBuilder diagnoseExplicitConv(Sema &S, SourceLocation Loc, 2392 QualType T, 2393 QualType ConvTy) override { 2394 return S.Diag(Loc, diag::err_delete_explicit_conversion) << T << ConvTy; 2395 } 2396 2397 SemaDiagnosticBuilder noteExplicitConv(Sema &S, CXXConversionDecl *Conv, 2398 QualType ConvTy) override { 2399 return S.Diag(Conv->getLocation(), diag::note_delete_conversion) 2400 << ConvTy; 2401 } 2402 2403 SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc, 2404 QualType T) override { 2405 return S.Diag(Loc, diag::err_ambiguous_delete_operand) << T; 2406 } 2407 2408 SemaDiagnosticBuilder noteAmbiguous(Sema &S, CXXConversionDecl *Conv, 2409 QualType ConvTy) override { 2410 return S.Diag(Conv->getLocation(), diag::note_delete_conversion) 2411 << ConvTy; 2412 } 2413 2414 SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc, 2415 QualType T, 2416 QualType ConvTy) override { 2417 llvm_unreachable("conversion functions are permitted"); 2418 } 2419 } Converter; 2420 2421 Ex = PerformContextualImplicitConversion(StartLoc, Ex.get(), Converter); 2422 if (Ex.isInvalid()) 2423 return ExprError(); 2424 Type = Ex.get()->getType(); 2425 if (!Converter.match(Type)) 2426 // FIXME: PerformContextualImplicitConversion should return ExprError 2427 // itself in this case. 2428 return ExprError(); 2429 2430 QualType Pointee = Type->getAs<PointerType>()->getPointeeType(); 2431 QualType PointeeElem = Context.getBaseElementType(Pointee); 2432 2433 if (unsigned AddressSpace = Pointee.getAddressSpace()) 2434 return Diag(Ex.get()->getLocStart(), 2435 diag::err_address_space_qualified_delete) 2436 << Pointee.getUnqualifiedType() << AddressSpace; 2437 2438 CXXRecordDecl *PointeeRD = nullptr; 2439 if (Pointee->isVoidType() && !isSFINAEContext()) { 2440 // The C++ standard bans deleting a pointer to a non-object type, which 2441 // effectively bans deletion of "void*". However, most compilers support 2442 // this, so we treat it as a warning unless we're in a SFINAE context. 2443 Diag(StartLoc, diag::ext_delete_void_ptr_operand) 2444 << Type << Ex.get()->getSourceRange(); 2445 } else if (Pointee->isFunctionType() || Pointee->isVoidType()) { 2446 return ExprError(Diag(StartLoc, diag::err_delete_operand) 2447 << Type << Ex.get()->getSourceRange()); 2448 } else if (!Pointee->isDependentType()) { 2449 if (!RequireCompleteType(StartLoc, Pointee, 2450 diag::warn_delete_incomplete, Ex.get())) { 2451 if (const RecordType *RT = PointeeElem->getAs<RecordType>()) 2452 PointeeRD = cast<CXXRecordDecl>(RT->getDecl()); 2453 } 2454 } 2455 2456 // C++ [expr.delete]p2: 2457 // [Note: a pointer to a const type can be the operand of a 2458 // delete-expression; it is not necessary to cast away the constness 2459 // (5.2.11) of the pointer expression before it is used as the operand 2460 // of the delete-expression. ] 2461 2462 if (Pointee->isArrayType() && !ArrayForm) { 2463 Diag(StartLoc, diag::warn_delete_array_type) 2464 << Type << Ex.get()->getSourceRange() 2465 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(StartLoc), "[]"); 2466 ArrayForm = true; 2467 } 2468 2469 DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName( 2470 ArrayForm ? OO_Array_Delete : OO_Delete); 2471 2472 if (PointeeRD) { 2473 if (!UseGlobal && 2474 FindDeallocationFunction(StartLoc, PointeeRD, DeleteName, 2475 OperatorDelete)) 2476 return ExprError(); 2477 2478 // If we're allocating an array of records, check whether the 2479 // usual operator delete[] has a size_t parameter. 2480 if (ArrayForm) { 2481 // If the user specifically asked to use the global allocator, 2482 // we'll need to do the lookup into the class. 2483 if (UseGlobal) 2484 UsualArrayDeleteWantsSize = 2485 doesUsualArrayDeleteWantSize(*this, StartLoc, PointeeElem); 2486 2487 // Otherwise, the usual operator delete[] should be the 2488 // function we just found. 2489 else if (OperatorDelete && isa<CXXMethodDecl>(OperatorDelete)) 2490 UsualArrayDeleteWantsSize = (OperatorDelete->getNumParams() == 2); 2491 } 2492 2493 if (!PointeeRD->hasIrrelevantDestructor()) 2494 if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) { 2495 MarkFunctionReferenced(StartLoc, 2496 const_cast<CXXDestructorDecl*>(Dtor)); 2497 if (DiagnoseUseOfDecl(Dtor, StartLoc)) 2498 return ExprError(); 2499 } 2500 2501 // C++ [expr.delete]p3: 2502 // In the first alternative (delete object), if the static type of the 2503 // object to be deleted is different from its dynamic type, the static 2504 // type shall be a base class of the dynamic type of the object to be 2505 // deleted and the static type shall have a virtual destructor or the 2506 // behavior is undefined. 2507 // 2508 // Note: a final class cannot be derived from, no issue there 2509 if (PointeeRD->isPolymorphic() && !PointeeRD->hasAttr<FinalAttr>()) { 2510 CXXDestructorDecl *dtor = PointeeRD->getDestructor(); 2511 if (dtor && !dtor->isVirtual()) { 2512 if (PointeeRD->isAbstract()) { 2513 // If the class is abstract, we warn by default, because we're 2514 // sure the code has undefined behavior. 2515 Diag(StartLoc, diag::warn_delete_abstract_non_virtual_dtor) 2516 << PointeeElem; 2517 } else if (!ArrayForm) { 2518 // Otherwise, if this is not an array delete, it's a bit suspect, 2519 // but not necessarily wrong. 2520 Diag(StartLoc, diag::warn_delete_non_virtual_dtor) << PointeeElem; 2521 } 2522 } 2523 } 2524 2525 } 2526 2527 if (!OperatorDelete) 2528 // Look for a global declaration. 2529 OperatorDelete = FindUsualDeallocationFunction( 2530 StartLoc, !RequireCompleteType(StartLoc, Pointee, 0) && 2531 (!ArrayForm || UsualArrayDeleteWantsSize || 2532 Pointee.isDestructedType()), 2533 DeleteName); 2534 2535 MarkFunctionReferenced(StartLoc, OperatorDelete); 2536 2537 // Check access and ambiguity of operator delete and destructor. 2538 if (PointeeRD) { 2539 if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) { 2540 CheckDestructorAccess(Ex.get()->getExprLoc(), Dtor, 2541 PDiag(diag::err_access_dtor) << PointeeElem); 2542 } 2543 } 2544 } 2545 2546 return new (Context) CXXDeleteExpr( 2547 Context.VoidTy, UseGlobal, ArrayForm, ArrayFormAsWritten, 2548 UsualArrayDeleteWantsSize, OperatorDelete, Ex.get(), StartLoc); 2549} 2550 2551/// \brief Check the use of the given variable as a C++ condition in an if, 2552/// while, do-while, or switch statement. 2553ExprResult Sema::CheckConditionVariable(VarDecl *ConditionVar, 2554 SourceLocation StmtLoc, 2555 bool ConvertToBoolean) { 2556 if (ConditionVar->isInvalidDecl()) 2557 return ExprError(); 2558 2559 QualType T = ConditionVar->getType(); 2560 2561 // C++ [stmt.select]p2: 2562 // The declarator shall not specify a function or an array. 2563 if (T->isFunctionType()) 2564 return ExprError(Diag(ConditionVar->getLocation(), 2565 diag::err_invalid_use_of_function_type) 2566 << ConditionVar->getSourceRange()); 2567 else if (T->isArrayType()) 2568 return ExprError(Diag(ConditionVar->getLocation(), 2569 diag::err_invalid_use_of_array_type) 2570 << ConditionVar->getSourceRange()); 2571 2572 ExprResult Condition = DeclRefExpr::Create( 2573 Context, NestedNameSpecifierLoc(), SourceLocation(), ConditionVar, 2574 /*enclosing*/ false, ConditionVar->getLocation(), 2575 ConditionVar->getType().getNonReferenceType(), VK_LValue); 2576 2577 MarkDeclRefReferenced(cast<DeclRefExpr>(Condition.get())); 2578 2579 if (ConvertToBoolean) { 2580 Condition = CheckBooleanCondition(Condition.get(), StmtLoc); 2581 if (Condition.isInvalid()) 2582 return ExprError(); 2583 } 2584 2585 return Condition; 2586} 2587 2588/// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid. 2589ExprResult Sema::CheckCXXBooleanCondition(Expr *CondExpr) { 2590 // C++ 6.4p4: 2591 // The value of a condition that is an initialized declaration in a statement 2592 // other than a switch statement is the value of the declared variable 2593 // implicitly converted to type bool. If that conversion is ill-formed, the 2594 // program is ill-formed. 2595 // The value of a condition that is an expression is the value of the 2596 // expression, implicitly converted to bool. 2597 // 2598 return PerformContextuallyConvertToBool(CondExpr); 2599} 2600 2601/// Helper function to determine whether this is the (deprecated) C++ 2602/// conversion from a string literal to a pointer to non-const char or 2603/// non-const wchar_t (for narrow and wide string literals, 2604/// respectively). 2605bool 2606Sema::IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType) { 2607 // Look inside the implicit cast, if it exists. 2608 if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From)) 2609 From = Cast->getSubExpr(); 2610 2611 // A string literal (2.13.4) that is not a wide string literal can 2612 // be converted to an rvalue of type "pointer to char"; a wide 2613 // string literal can be converted to an rvalue of type "pointer 2614 // to wchar_t" (C++ 4.2p2). 2615 if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From->IgnoreParens())) 2616 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) 2617 if (const BuiltinType *ToPointeeType 2618 = ToPtrType->getPointeeType()->getAs<BuiltinType>()) { 2619 // This conversion is considered only when there is an 2620 // explicit appropriate pointer target type (C++ 4.2p2). 2621 if (!ToPtrType->getPointeeType().hasQualifiers()) { 2622 switch (StrLit->getKind()) { 2623 case StringLiteral::UTF8: 2624 case StringLiteral::UTF16: 2625 case StringLiteral::UTF32: 2626 // We don't allow UTF literals to be implicitly converted 2627 break; 2628 case StringLiteral::Ascii: 2629 return (ToPointeeType->getKind() == BuiltinType::Char_U || 2630 ToPointeeType->getKind() == BuiltinType::Char_S); 2631 case StringLiteral::Wide: 2632 return ToPointeeType->isWideCharType(); 2633 } 2634 } 2635 } 2636 2637 return false; 2638} 2639 2640static ExprResult BuildCXXCastArgument(Sema &S, 2641 SourceLocation CastLoc, 2642 QualType Ty, 2643 CastKind Kind, 2644 CXXMethodDecl *Method, 2645 DeclAccessPair FoundDecl, 2646 bool HadMultipleCandidates, 2647 Expr *From) { 2648 switch (Kind) { 2649 default: llvm_unreachable("Unhandled cast kind!"); 2650 case CK_ConstructorConversion: { 2651 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Method); 2652 SmallVector<Expr*, 8> ConstructorArgs; 2653 2654 if (S.RequireNonAbstractType(CastLoc, Ty, 2655 diag::err_allocation_of_abstract_type)) 2656 return ExprError(); 2657 2658 if (S.CompleteConstructorCall(Constructor, From, CastLoc, ConstructorArgs)) 2659 return ExprError(); 2660 2661 S.CheckConstructorAccess(CastLoc, Constructor, 2662 InitializedEntity::InitializeTemporary(Ty), 2663 Constructor->getAccess()); 2664 if (S.DiagnoseUseOfDecl(Method, CastLoc)) 2665 return ExprError(); 2666 2667 ExprResult Result = S.BuildCXXConstructExpr( 2668 CastLoc, Ty, cast<CXXConstructorDecl>(Method), 2669 ConstructorArgs, HadMultipleCandidates, 2670 /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false, 2671 CXXConstructExpr::CK_Complete, SourceRange()); 2672 if (Result.isInvalid()) 2673 return ExprError(); 2674 2675 return S.MaybeBindToTemporary(Result.getAs<Expr>()); 2676 } 2677 2678 case CK_UserDefinedConversion: { 2679 assert(!From->getType()->isPointerType() && "Arg can't have pointer type!"); 2680 2681 S.CheckMemberOperatorAccess(CastLoc, From, /*arg*/ nullptr, FoundDecl); 2682 if (S.DiagnoseUseOfDecl(Method, CastLoc)) 2683 return ExprError(); 2684 2685 // Create an implicit call expr that calls it. 2686 CXXConversionDecl *Conv = cast<CXXConversionDecl>(Method); 2687 ExprResult Result = S.BuildCXXMemberCallExpr(From, FoundDecl, Conv, 2688 HadMultipleCandidates); 2689 if (Result.isInvalid()) 2690 return ExprError(); 2691 // Record usage of conversion in an implicit cast. 2692 Result = ImplicitCastExpr::Create(S.Context, Result.get()->getType(), 2693 CK_UserDefinedConversion, Result.get(), 2694 nullptr, Result.get()->getValueKind()); 2695 2696 return S.MaybeBindToTemporary(Result.get()); 2697 } 2698 } 2699} 2700 2701/// PerformImplicitConversion - Perform an implicit conversion of the 2702/// expression From to the type ToType using the pre-computed implicit 2703/// conversion sequence ICS. Returns the converted 2704/// expression. Action is the kind of conversion we're performing, 2705/// used in the error message. 2706ExprResult 2707Sema::PerformImplicitConversion(Expr *From, QualType ToType, 2708 const ImplicitConversionSequence &ICS, 2709 AssignmentAction Action, 2710 CheckedConversionKind CCK) { 2711 switch (ICS.getKind()) { 2712 case ImplicitConversionSequence::StandardConversion: { 2713 ExprResult Res = PerformImplicitConversion(From, ToType, ICS.Standard, 2714 Action, CCK); 2715 if (Res.isInvalid()) 2716 return ExprError(); 2717 From = Res.get(); 2718 break; 2719 } 2720 2721 case ImplicitConversionSequence::UserDefinedConversion: { 2722 2723 FunctionDecl *FD = ICS.UserDefined.ConversionFunction; 2724 CastKind CastKind; 2725 QualType BeforeToType; 2726 assert(FD && "no conversion function for user-defined conversion seq"); 2727 if (const CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(FD)) { 2728 CastKind = CK_UserDefinedConversion; 2729 2730 // If the user-defined conversion is specified by a conversion function, 2731 // the initial standard conversion sequence converts the source type to 2732 // the implicit object parameter of the conversion function. 2733 BeforeToType = Context.getTagDeclType(Conv->getParent()); 2734 } else { 2735 const CXXConstructorDecl *Ctor = cast<CXXConstructorDecl>(FD); 2736 CastKind = CK_ConstructorConversion; 2737 // Do no conversion if dealing with ... for the first conversion. 2738 if (!ICS.UserDefined.EllipsisConversion) { 2739 // If the user-defined conversion is specified by a constructor, the 2740 // initial standard conversion sequence converts the source type to 2741 // the type required by the argument of the constructor 2742 BeforeToType = Ctor->getParamDecl(0)->getType().getNonReferenceType(); 2743 } 2744 } 2745 // Watch out for ellipsis conversion. 2746 if (!ICS.UserDefined.EllipsisConversion) { 2747 ExprResult Res = 2748 PerformImplicitConversion(From, BeforeToType, 2749 ICS.UserDefined.Before, AA_Converting, 2750 CCK); 2751 if (Res.isInvalid()) 2752 return ExprError(); 2753 From = Res.get(); 2754 } 2755 2756 ExprResult CastArg 2757 = BuildCXXCastArgument(*this, 2758 From->getLocStart(), 2759 ToType.getNonReferenceType(), 2760 CastKind, cast<CXXMethodDecl>(FD), 2761 ICS.UserDefined.FoundConversionFunction, 2762 ICS.UserDefined.HadMultipleCandidates, 2763 From); 2764 2765 if (CastArg.isInvalid()) 2766 return ExprError(); 2767 2768 From = CastArg.get(); 2769 2770 return PerformImplicitConversion(From, ToType, ICS.UserDefined.After, 2771 AA_Converting, CCK); 2772 } 2773 2774 case ImplicitConversionSequence::AmbiguousConversion: 2775 ICS.DiagnoseAmbiguousConversion(*this, From->getExprLoc(), 2776 PDiag(diag::err_typecheck_ambiguous_condition) 2777 << From->getSourceRange()); 2778 return ExprError(); 2779 2780 case ImplicitConversionSequence::EllipsisConversion: 2781 llvm_unreachable("Cannot perform an ellipsis conversion"); 2782 2783 case ImplicitConversionSequence::BadConversion: 2784 return ExprError(); 2785 } 2786 2787 // Everything went well. 2788 return From; 2789} 2790 2791/// PerformImplicitConversion - Perform an implicit conversion of the 2792/// expression From to the type ToType by following the standard 2793/// conversion sequence SCS. Returns the converted 2794/// expression. Flavor is the context in which we're performing this 2795/// conversion, for use in error messages. 2796ExprResult 2797Sema::PerformImplicitConversion(Expr *From, QualType ToType, 2798 const StandardConversionSequence& SCS, 2799 AssignmentAction Action, 2800 CheckedConversionKind CCK) { 2801 bool CStyle = (CCK == CCK_CStyleCast || CCK == CCK_FunctionalCast); 2802 2803 // Overall FIXME: we are recomputing too many types here and doing far too 2804 // much extra work. What this means is that we need to keep track of more 2805 // information that is computed when we try the implicit conversion initially, 2806 // so that we don't need to recompute anything here. 2807 QualType FromType = From->getType(); 2808 2809 if (SCS.CopyConstructor) { 2810 // FIXME: When can ToType be a reference type? 2811 assert(!ToType->isReferenceType()); 2812 if (SCS.Second == ICK_Derived_To_Base) { 2813 SmallVector<Expr*, 8> ConstructorArgs; 2814 if (CompleteConstructorCall(cast<CXXConstructorDecl>(SCS.CopyConstructor), 2815 From, /*FIXME:ConstructLoc*/SourceLocation(), 2816 ConstructorArgs)) 2817 return ExprError(); 2818 return BuildCXXConstructExpr( 2819 /*FIXME:ConstructLoc*/ SourceLocation(), ToType, SCS.CopyConstructor, 2820 ConstructorArgs, /*HadMultipleCandidates*/ false, 2821 /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false, 2822 CXXConstructExpr::CK_Complete, SourceRange()); 2823 } 2824 return BuildCXXConstructExpr( 2825 /*FIXME:ConstructLoc*/ SourceLocation(), ToType, SCS.CopyConstructor, 2826 From, /*HadMultipleCandidates*/ false, 2827 /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false, 2828 CXXConstructExpr::CK_Complete, SourceRange()); 2829 } 2830 2831 // Resolve overloaded function references. 2832 if (Context.hasSameType(FromType, Context.OverloadTy)) { 2833 DeclAccessPair Found; 2834 FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(From, ToType, 2835 true, Found); 2836 if (!Fn) 2837 return ExprError(); 2838 2839 if (DiagnoseUseOfDecl(Fn, From->getLocStart())) 2840 return ExprError(); 2841 2842 From = FixOverloadedFunctionReference(From, Found, Fn); 2843 FromType = From->getType(); 2844 } 2845 2846 // If we're converting to an atomic type, first convert to the corresponding 2847 // non-atomic type. 2848 QualType ToAtomicType; 2849 if (const AtomicType *ToAtomic = ToType->getAs<AtomicType>()) { 2850 ToAtomicType = ToType; 2851 ToType = ToAtomic->getValueType(); 2852 } 2853 2854 // Perform the first implicit conversion. 2855 switch (SCS.First) { 2856 case ICK_Identity: 2857 if (const AtomicType *FromAtomic = FromType->getAs<AtomicType>()) { 2858 FromType = FromAtomic->getValueType().getUnqualifiedType(); 2859 From = ImplicitCastExpr::Create(Context, FromType, CK_AtomicToNonAtomic, 2860 From, /*BasePath=*/nullptr, VK_RValue); 2861 } 2862 break; 2863 2864 case ICK_Lvalue_To_Rvalue: { 2865 assert(From->getObjectKind() != OK_ObjCProperty); 2866 ExprResult FromRes = DefaultLvalueConversion(From); 2867 assert(!FromRes.isInvalid() && "Can't perform deduced conversion?!"); 2868 From = FromRes.get(); 2869 FromType = From->getType(); 2870 break; 2871 } 2872 2873 case ICK_Array_To_Pointer: 2874 FromType = Context.getArrayDecayedType(FromType); 2875 From = ImpCastExprToType(From, FromType, CK_ArrayToPointerDecay, 2876 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2877 break; 2878 2879 case ICK_Function_To_Pointer: 2880 FromType = Context.getPointerType(FromType); 2881 From = ImpCastExprToType(From, FromType, CK_FunctionToPointerDecay, 2882 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2883 break; 2884 2885 default: 2886 llvm_unreachable("Improper first standard conversion"); 2887 } 2888 2889 // Perform the second implicit conversion 2890 switch (SCS.Second) { 2891 case ICK_Identity: 2892 // C++ [except.spec]p5: 2893 // [For] assignment to and initialization of pointers to functions, 2894 // pointers to member functions, and references to functions: the 2895 // target entity shall allow at least the exceptions allowed by the 2896 // source value in the assignment or initialization. 2897 switch (Action) { 2898 case AA_Assigning: 2899 case AA_Initializing: 2900 // Note, function argument passing and returning are initialization. 2901 case AA_Passing: 2902 case AA_Returning: 2903 case AA_Sending: 2904 case AA_Passing_CFAudited: 2905 if (CheckExceptionSpecCompatibility(From, ToType)) 2906 return ExprError(); 2907 break; 2908 2909 case AA_Casting: 2910 case AA_Converting: 2911 // Casts and implicit conversions are not initialization, so are not 2912 // checked for exception specification mismatches. 2913 break; 2914 } 2915 // Nothing else to do. 2916 break; 2917 2918 case ICK_NoReturn_Adjustment: 2919 // If both sides are functions (or pointers/references to them), there could 2920 // be incompatible exception declarations. 2921 if (CheckExceptionSpecCompatibility(From, ToType)) 2922 return ExprError(); 2923 2924 From = ImpCastExprToType(From, ToType, CK_NoOp, 2925 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2926 break; 2927 2928 case ICK_Integral_Promotion: 2929 case ICK_Integral_Conversion: 2930 if (ToType->isBooleanType()) { 2931 assert(FromType->castAs<EnumType>()->getDecl()->isFixed() && 2932 SCS.Second == ICK_Integral_Promotion && 2933 "only enums with fixed underlying type can promote to bool"); 2934 From = ImpCastExprToType(From, ToType, CK_IntegralToBoolean, 2935 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2936 } else { 2937 From = ImpCastExprToType(From, ToType, CK_IntegralCast, 2938 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2939 } 2940 break; 2941 2942 case ICK_Floating_Promotion: 2943 case ICK_Floating_Conversion: 2944 From = ImpCastExprToType(From, ToType, CK_FloatingCast, 2945 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2946 break; 2947 2948 case ICK_Complex_Promotion: 2949 case ICK_Complex_Conversion: { 2950 QualType FromEl = From->getType()->getAs<ComplexType>()->getElementType(); 2951 QualType ToEl = ToType->getAs<ComplexType>()->getElementType(); 2952 CastKind CK; 2953 if (FromEl->isRealFloatingType()) { 2954 if (ToEl->isRealFloatingType()) 2955 CK = CK_FloatingComplexCast; 2956 else 2957 CK = CK_FloatingComplexToIntegralComplex; 2958 } else if (ToEl->isRealFloatingType()) { 2959 CK = CK_IntegralComplexToFloatingComplex; 2960 } else { 2961 CK = CK_IntegralComplexCast; 2962 } 2963 From = ImpCastExprToType(From, ToType, CK, 2964 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2965 break; 2966 } 2967 2968 case ICK_Floating_Integral: 2969 if (ToType->isRealFloatingType()) 2970 From = ImpCastExprToType(From, ToType, CK_IntegralToFloating, 2971 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2972 else 2973 From = ImpCastExprToType(From, ToType, CK_FloatingToIntegral, 2974 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2975 break; 2976 2977 case ICK_Compatible_Conversion: 2978 From = ImpCastExprToType(From, ToType, CK_NoOp, 2979 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 2980 break; 2981 2982 case ICK_Writeback_Conversion: 2983 case ICK_Pointer_Conversion: { 2984 if (SCS.IncompatibleObjC && Action != AA_Casting) { 2985 // Diagnose incompatible Objective-C conversions 2986 if (Action == AA_Initializing || Action == AA_Assigning) 2987 Diag(From->getLocStart(), 2988 diag::ext_typecheck_convert_incompatible_pointer) 2989 << ToType << From->getType() << Action 2990 << From->getSourceRange() << 0; 2991 else 2992 Diag(From->getLocStart(), 2993 diag::ext_typecheck_convert_incompatible_pointer) 2994 << From->getType() << ToType << Action 2995 << From->getSourceRange() << 0; 2996 2997 if (From->getType()->isObjCObjectPointerType() && 2998 ToType->isObjCObjectPointerType()) 2999 EmitRelatedResultTypeNote(From); 3000 } 3001 else if (getLangOpts().ObjCAutoRefCount && 3002 !CheckObjCARCUnavailableWeakConversion(ToType, 3003 From->getType())) { 3004 if (Action == AA_Initializing) 3005 Diag(From->getLocStart(), 3006 diag::err_arc_weak_unavailable_assign); 3007 else 3008 Diag(From->getLocStart(), 3009 diag::err_arc_convesion_of_weak_unavailable) 3010 << (Action == AA_Casting) << From->getType() << ToType 3011 << From->getSourceRange(); 3012 } 3013 3014 CastKind Kind = CK_Invalid; 3015 CXXCastPath BasePath; 3016 if (CheckPointerConversion(From, ToType, Kind, BasePath, CStyle)) 3017 return ExprError(); 3018 3019 // Make sure we extend blocks if necessary. 3020 // FIXME: doing this here is really ugly. 3021 if (Kind == CK_BlockPointerToObjCPointerCast) { 3022 ExprResult E = From; 3023 (void) PrepareCastToObjCObjectPointer(E); 3024 From = E.get(); 3025 } 3026 if (getLangOpts().ObjCAutoRefCount) 3027 CheckObjCARCConversion(SourceRange(), ToType, From, CCK); 3028 From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK) 3029 .get(); 3030 break; 3031 } 3032 3033 case ICK_Pointer_Member: { 3034 CastKind Kind = CK_Invalid; 3035 CXXCastPath BasePath; 3036 if (CheckMemberPointerConversion(From, ToType, Kind, BasePath, CStyle)) 3037 return ExprError(); 3038 if (CheckExceptionSpecCompatibility(From, ToType)) 3039 return ExprError(); 3040 3041 // We may not have been able to figure out what this member pointer resolved 3042 // to up until this exact point. Attempt to lock-in it's inheritance model. 3043 QualType FromType = From->getType(); 3044 if (FromType->isMemberPointerType()) 3045 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) 3046 RequireCompleteType(From->getExprLoc(), FromType, 0); 3047 3048 From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK) 3049 .get(); 3050 break; 3051 } 3052 3053 case ICK_Boolean_Conversion: 3054 // Perform half-to-boolean conversion via float. 3055 if (From->getType()->isHalfType()) { 3056 From = ImpCastExprToType(From, Context.FloatTy, CK_FloatingCast).get(); 3057 FromType = Context.FloatTy; 3058 } 3059 3060 From = ImpCastExprToType(From, Context.BoolTy, 3061 ScalarTypeToBooleanCastKind(FromType), 3062 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 3063 break; 3064 3065 case ICK_Derived_To_Base: { 3066 CXXCastPath BasePath; 3067 if (CheckDerivedToBaseConversion(From->getType(), 3068 ToType.getNonReferenceType(), 3069 From->getLocStart(), 3070 From->getSourceRange(), 3071 &BasePath, 3072 CStyle)) 3073 return ExprError(); 3074 3075 From = ImpCastExprToType(From, ToType.getNonReferenceType(), 3076 CK_DerivedToBase, From->getValueKind(), 3077 &BasePath, CCK).get(); 3078 break; 3079 } 3080 3081 case ICK_Vector_Conversion: 3082 From = ImpCastExprToType(From, ToType, CK_BitCast, 3083 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 3084 break; 3085 3086 case ICK_Vector_Splat: 3087 // Vector splat from any arithmetic type to a vector. 3088 // Cast to the element type. 3089 { 3090 QualType elType = ToType->getAs<ExtVectorType>()->getElementType(); 3091 if (elType != From->getType()) { 3092 ExprResult E = From; 3093 From = ImpCastExprToType(From, elType, 3094 PrepareScalarCast(E, elType)).get(); 3095 } 3096 From = ImpCastExprToType(From, ToType, CK_VectorSplat, 3097 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 3098 } 3099 break; 3100 3101 case ICK_Complex_Real: 3102 // Case 1. x -> _Complex y 3103 if (const ComplexType *ToComplex = ToType->getAs<ComplexType>()) { 3104 QualType ElType = ToComplex->getElementType(); 3105 bool isFloatingComplex = ElType->isRealFloatingType(); 3106 3107 // x -> y 3108 if (Context.hasSameUnqualifiedType(ElType, From->getType())) { 3109 // do nothing 3110 } else if (From->getType()->isRealFloatingType()) { 3111 From = ImpCastExprToType(From, ElType, 3112 isFloatingComplex ? CK_FloatingCast : CK_FloatingToIntegral).get(); 3113 } else { 3114 assert(From->getType()->isIntegerType()); 3115 From = ImpCastExprToType(From, ElType, 3116 isFloatingComplex ? CK_IntegralToFloating : CK_IntegralCast).get(); 3117 } 3118 // y -> _Complex y 3119 From = ImpCastExprToType(From, ToType, 3120 isFloatingComplex ? CK_FloatingRealToComplex 3121 : CK_IntegralRealToComplex).get(); 3122 3123 // Case 2. _Complex x -> y 3124 } else { 3125 const ComplexType *FromComplex = From->getType()->getAs<ComplexType>(); 3126 assert(FromComplex); 3127 3128 QualType ElType = FromComplex->getElementType(); 3129 bool isFloatingComplex = ElType->isRealFloatingType(); 3130 3131 // _Complex x -> x 3132 From = ImpCastExprToType(From, ElType, 3133 isFloatingComplex ? CK_FloatingComplexToReal 3134 : CK_IntegralComplexToReal, 3135 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 3136 3137 // x -> y 3138 if (Context.hasSameUnqualifiedType(ElType, ToType)) { 3139 // do nothing 3140 } else if (ToType->isRealFloatingType()) { 3141 From = ImpCastExprToType(From, ToType, 3142 isFloatingComplex ? CK_FloatingCast : CK_IntegralToFloating, 3143 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 3144 } else { 3145 assert(ToType->isIntegerType()); 3146 From = ImpCastExprToType(From, ToType, 3147 isFloatingComplex ? CK_FloatingToIntegral : CK_IntegralCast, 3148 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 3149 } 3150 } 3151 break; 3152 3153 case ICK_Block_Pointer_Conversion: { 3154 From = ImpCastExprToType(From, ToType.getUnqualifiedType(), CK_BitCast, 3155 VK_RValue, /*BasePath=*/nullptr, CCK).get(); 3156 break; 3157 } 3158 3159 case ICK_TransparentUnionConversion: { 3160 ExprResult FromRes = From; 3161 Sema::AssignConvertType ConvTy = 3162 CheckTransparentUnionArgumentConstraints(ToType, FromRes); 3163 if (FromRes.isInvalid()) 3164 return ExprError(); 3165 From = FromRes.get(); 3166 assert ((ConvTy == Sema::Compatible) && 3167 "Improper transparent union conversion"); 3168 (void)ConvTy; 3169 break; 3170 } 3171 3172 case ICK_Zero_Event_Conversion: 3173 From = ImpCastExprToType(From, ToType, 3174 CK_ZeroToOCLEvent, 3175 From->getValueKind()).get(); 3176 break; 3177 3178 case ICK_Lvalue_To_Rvalue: 3179 case ICK_Array_To_Pointer: 3180 case ICK_Function_To_Pointer: 3181 case ICK_Qualification: 3182 case ICK_Num_Conversion_Kinds: 3183 llvm_unreachable("Improper second standard conversion"); 3184 } 3185 3186 switch (SCS.Third) { 3187 case ICK_Identity: 3188 // Nothing to do. 3189 break; 3190 3191 case ICK_Qualification: { 3192 // The qualification keeps the category of the inner expression, unless the 3193 // target type isn't a reference. 3194 ExprValueKind VK = ToType->isReferenceType() ? 3195 From->getValueKind() : VK_RValue; 3196 From = ImpCastExprToType(From, ToType.getNonLValueExprType(Context), 3197 CK_NoOp, VK, /*BasePath=*/nullptr, CCK).get(); 3198 3199 if (SCS.DeprecatedStringLiteralToCharPtr && 3200 !getLangOpts().WritableStrings) { 3201 Diag(From->getLocStart(), getLangOpts().CPlusPlus11 3202 ? diag::ext_deprecated_string_literal_conversion 3203 : diag::warn_deprecated_string_literal_conversion) 3204 << ToType.getNonReferenceType(); 3205 } 3206 3207 break; 3208 } 3209 3210 default: 3211 llvm_unreachable("Improper third standard conversion"); 3212 } 3213 3214 // If this conversion sequence involved a scalar -> atomic conversion, perform 3215 // that conversion now. 3216 if (!ToAtomicType.isNull()) { 3217 assert(Context.hasSameType( 3218 ToAtomicType->castAs<AtomicType>()->getValueType(), From->getType())); 3219 From = ImpCastExprToType(From, ToAtomicType, CK_NonAtomicToAtomic, 3220 VK_RValue, nullptr, CCK).get(); 3221 } 3222 3223 return From; 3224} 3225 3226/// \brief Check the completeness of a type in a unary type trait. 3227/// 3228/// If the particular type trait requires a complete type, tries to complete 3229/// it. If completing the type fails, a diagnostic is emitted and false 3230/// returned. If completing the type succeeds or no completion was required, 3231/// returns true. 3232static bool CheckUnaryTypeTraitTypeCompleteness(Sema &S, TypeTrait UTT, 3233 SourceLocation Loc, 3234 QualType ArgTy) { 3235 // C++0x [meta.unary.prop]p3: 3236 // For all of the class templates X declared in this Clause, instantiating 3237 // that template with a template argument that is a class template 3238 // specialization may result in the implicit instantiation of the template 3239 // argument if and only if the semantics of X require that the argument 3240 // must be a complete type. 3241 // We apply this rule to all the type trait expressions used to implement 3242 // these class templates. We also try to follow any GCC documented behavior 3243 // in these expressions to ensure portability of standard libraries. 3244 switch (UTT) { 3245 default: llvm_unreachable("not a UTT"); 3246 // is_complete_type somewhat obviously cannot require a complete type. 3247 case UTT_IsCompleteType: 3248 // Fall-through 3249 3250 // These traits are modeled on the type predicates in C++0x 3251 // [meta.unary.cat] and [meta.unary.comp]. They are not specified as 3252 // requiring a complete type, as whether or not they return true cannot be 3253 // impacted by the completeness of the type. 3254 case UTT_IsVoid: 3255 case UTT_IsIntegral: 3256 case UTT_IsFloatingPoint: 3257 case UTT_IsArray: 3258 case UTT_IsPointer: 3259 case UTT_IsLvalueReference: 3260 case UTT_IsRvalueReference: 3261 case UTT_IsMemberFunctionPointer: 3262 case UTT_IsMemberObjectPointer: 3263 case UTT_IsEnum: 3264 case UTT_IsUnion: 3265 case UTT_IsClass: 3266 case UTT_IsFunction: 3267 case UTT_IsReference: 3268 case UTT_IsArithmetic: 3269 case UTT_IsFundamental: 3270 case UTT_IsObject: 3271 case UTT_IsScalar: 3272 case UTT_IsCompound: 3273 case UTT_IsMemberPointer: 3274 // Fall-through 3275 3276 // These traits are modeled on type predicates in C++0x [meta.unary.prop] 3277 // which requires some of its traits to have the complete type. However, 3278 // the completeness of the type cannot impact these traits' semantics, and 3279 // so they don't require it. This matches the comments on these traits in 3280 // Table 49. 3281 case UTT_IsConst: 3282 case UTT_IsVolatile: 3283 case UTT_IsSigned: 3284 case UTT_IsUnsigned: 3285 return true; 3286 3287 // C++0x [meta.unary.prop] Table 49 requires the following traits to be 3288 // applied to a complete type. 3289 case UTT_IsTrivial: 3290 case UTT_IsTriviallyCopyable: 3291 case UTT_IsStandardLayout: 3292 case UTT_IsPOD: 3293 case UTT_IsLiteral: 3294 case UTT_IsEmpty: 3295 case UTT_IsPolymorphic: 3296 case UTT_IsAbstract: 3297 case UTT_IsInterfaceClass: 3298 case UTT_IsDestructible: 3299 case UTT_IsNothrowDestructible: 3300 // Fall-through 3301 3302 // These traits require a complete type. 3303 case UTT_IsFinal: 3304 case UTT_IsSealed: 3305 3306 // These trait expressions are designed to help implement predicates in 3307 // [meta.unary.prop] despite not being named the same. They are specified 3308 // by both GCC and the Embarcadero C++ compiler, and require the complete 3309 // type due to the overarching C++0x type predicates being implemented 3310 // requiring the complete type. 3311 case UTT_HasNothrowAssign: 3312 case UTT_HasNothrowMoveAssign: 3313 case UTT_HasNothrowConstructor: 3314 case UTT_HasNothrowCopy: 3315 case UTT_HasTrivialAssign: 3316 case UTT_HasTrivialMoveAssign: 3317 case UTT_HasTrivialDefaultConstructor: 3318 case UTT_HasTrivialMoveConstructor: 3319 case UTT_HasTrivialCopy: 3320 case UTT_HasTrivialDestructor: 3321 case UTT_HasVirtualDestructor: 3322 // Arrays of unknown bound are expressly allowed. 3323 QualType ElTy = ArgTy; 3324 if (ArgTy->isIncompleteArrayType()) 3325 ElTy = S.Context.getAsArrayType(ArgTy)->getElementType(); 3326 3327 // The void type is expressly allowed. 3328 if (ElTy->isVoidType()) 3329 return true; 3330 3331 return !S.RequireCompleteType( 3332 Loc, ElTy, diag::err_incomplete_type_used_in_type_trait_expr); 3333 } 3334} 3335 3336static bool HasNoThrowOperator(const RecordType *RT, OverloadedOperatorKind Op, 3337 Sema &Self, SourceLocation KeyLoc, ASTContext &C, 3338 bool (CXXRecordDecl::*HasTrivial)() const, 3339 bool (CXXRecordDecl::*HasNonTrivial)() const, 3340 bool (CXXMethodDecl::*IsDesiredOp)() const) 3341{ 3342 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 3343 if ((RD->*HasTrivial)() && !(RD->*HasNonTrivial)()) 3344 return true; 3345 3346 DeclarationName Name = C.DeclarationNames.getCXXOperatorName(Op); 3347 DeclarationNameInfo NameInfo(Name, KeyLoc); 3348 LookupResult Res(Self, NameInfo, Sema::LookupOrdinaryName); 3349 if (Self.LookupQualifiedName(Res, RD)) { 3350 bool FoundOperator = false; 3351 Res.suppressDiagnostics(); 3352 for (LookupResult::iterator Op = Res.begin(), OpEnd = Res.end(); 3353 Op != OpEnd; ++Op) { 3354 if (isa<FunctionTemplateDecl>(*Op)) 3355 continue; 3356 3357 CXXMethodDecl *Operator = cast<CXXMethodDecl>(*Op); 3358 if((Operator->*IsDesiredOp)()) { 3359 FoundOperator = true; 3360 const FunctionProtoType *CPT = 3361 Operator->getType()->getAs<FunctionProtoType>(); 3362 CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); 3363 if (!CPT || !CPT->isNothrow(C)) 3364 return false; 3365 } 3366 } 3367 return FoundOperator; 3368 } 3369 return false; 3370} 3371 3372static bool EvaluateUnaryTypeTrait(Sema &Self, TypeTrait UTT, 3373 SourceLocation KeyLoc, QualType T) { 3374 assert(!T->isDependentType() && "Cannot evaluate traits of dependent type"); 3375 3376 ASTContext &C = Self.Context; 3377 switch(UTT) { 3378 default: llvm_unreachable("not a UTT"); 3379 // Type trait expressions corresponding to the primary type category 3380 // predicates in C++0x [meta.unary.cat]. 3381 case UTT_IsVoid: 3382 return T->isVoidType(); 3383 case UTT_IsIntegral: 3384 return T->isIntegralType(C); 3385 case UTT_IsFloatingPoint: 3386 return T->isFloatingType(); 3387 case UTT_IsArray: 3388 return T->isArrayType(); 3389 case UTT_IsPointer: 3390 return T->isPointerType(); 3391 case UTT_IsLvalueReference: 3392 return T->isLValueReferenceType(); 3393 case UTT_IsRvalueReference: 3394 return T->isRValueReferenceType(); 3395 case UTT_IsMemberFunctionPointer: 3396 return T->isMemberFunctionPointerType(); 3397 case UTT_IsMemberObjectPointer: 3398 return T->isMemberDataPointerType(); 3399 case UTT_IsEnum: 3400 return T->isEnumeralType(); 3401 case UTT_IsUnion: 3402 return T->isUnionType(); 3403 case UTT_IsClass: 3404 return T->isClassType() || T->isStructureType() || T->isInterfaceType(); 3405 case UTT_IsFunction: 3406 return T->isFunctionType(); 3407 3408 // Type trait expressions which correspond to the convenient composition 3409 // predicates in C++0x [meta.unary.comp]. 3410 case UTT_IsReference: 3411 return T->isReferenceType(); 3412 case UTT_IsArithmetic: 3413 return T->isArithmeticType() && !T->isEnumeralType(); 3414 case UTT_IsFundamental: 3415 return T->isFundamentalType(); 3416 case UTT_IsObject: 3417 return T->isObjectType(); 3418 case UTT_IsScalar: 3419 // Note: semantic analysis depends on Objective-C lifetime types to be 3420 // considered scalar types. However, such types do not actually behave 3421 // like scalar types at run time (since they may require retain/release 3422 // operations), so we report them as non-scalar. 3423 if (T->isObjCLifetimeType()) { 3424 switch (T.getObjCLifetime()) { 3425 case Qualifiers::OCL_None: 3426 case Qualifiers::OCL_ExplicitNone: 3427 return true; 3428 3429 case Qualifiers::OCL_Strong: 3430 case Qualifiers::OCL_Weak: 3431 case Qualifiers::OCL_Autoreleasing: 3432 return false; 3433 } 3434 } 3435 3436 return T->isScalarType(); 3437 case UTT_IsCompound: 3438 return T->isCompoundType(); 3439 case UTT_IsMemberPointer: 3440 return T->isMemberPointerType(); 3441 3442 // Type trait expressions which correspond to the type property predicates 3443 // in C++0x [meta.unary.prop]. 3444 case UTT_IsConst: 3445 return T.isConstQualified(); 3446 case UTT_IsVolatile: 3447 return T.isVolatileQualified(); 3448 case UTT_IsTrivial: 3449 return T.isTrivialType(Self.Context); 3450 case UTT_IsTriviallyCopyable: 3451 return T.isTriviallyCopyableType(Self.Context); 3452 case UTT_IsStandardLayout: 3453 return T->isStandardLayoutType(); 3454 case UTT_IsPOD: 3455 return T.isPODType(Self.Context); 3456 case UTT_IsLiteral: 3457 return T->isLiteralType(Self.Context); 3458 case UTT_IsEmpty: 3459 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 3460 return !RD->isUnion() && RD->isEmpty(); 3461 return false; 3462 case UTT_IsPolymorphic: 3463 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 3464 return RD->isPolymorphic(); 3465 return false; 3466 case UTT_IsAbstract: 3467 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 3468 return RD->isAbstract(); 3469 return false; 3470 case UTT_IsInterfaceClass: 3471 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 3472 return RD->isInterface(); 3473 return false; 3474 case UTT_IsFinal: 3475 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 3476 return RD->hasAttr<FinalAttr>(); 3477 return false; 3478 case UTT_IsSealed: 3479 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 3480 if (FinalAttr *FA = RD->getAttr<FinalAttr>()) 3481 return FA->isSpelledAsSealed(); 3482 return false; 3483 case UTT_IsSigned: 3484 return T->isSignedIntegerType(); 3485 case UTT_IsUnsigned: 3486 return T->isUnsignedIntegerType(); 3487 3488 // Type trait expressions which query classes regarding their construction, 3489 // destruction, and copying. Rather than being based directly on the 3490 // related type predicates in the standard, they are specified by both 3491 // GCC[1] and the Embarcadero C++ compiler[2], and Clang implements those 3492 // specifications. 3493 // 3494 // 1: http://gcc.gnu/.org/onlinedocs/gcc/Type-Traits.html 3495 // 2: http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index 3496 // 3497 // Note that these builtins do not behave as documented in g++: if a class 3498 // has both a trivial and a non-trivial special member of a particular kind, 3499 // they return false! For now, we emulate this behavior. 3500 // FIXME: This appears to be a g++ bug: more complex cases reveal that it 3501 // does not correctly compute triviality in the presence of multiple special 3502 // members of the same kind. Revisit this once the g++ bug is fixed. 3503 case UTT_HasTrivialDefaultConstructor: 3504 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3505 // If __is_pod (type) is true then the trait is true, else if type is 3506 // a cv class or union type (or array thereof) with a trivial default 3507 // constructor ([class.ctor]) then the trait is true, else it is false. 3508 if (T.isPODType(Self.Context)) 3509 return true; 3510 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) 3511 return RD->hasTrivialDefaultConstructor() && 3512 !RD->hasNonTrivialDefaultConstructor(); 3513 return false; 3514 case UTT_HasTrivialMoveConstructor: 3515 // This trait is implemented by MSVC 2012 and needed to parse the 3516 // standard library headers. Specifically this is used as the logic 3517 // behind std::is_trivially_move_constructible (20.9.4.3). 3518 if (T.isPODType(Self.Context)) 3519 return true; 3520 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) 3521 return RD->hasTrivialMoveConstructor() && !RD->hasNonTrivialMoveConstructor(); 3522 return false; 3523 case UTT_HasTrivialCopy: 3524 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3525 // If __is_pod (type) is true or type is a reference type then 3526 // the trait is true, else if type is a cv class or union type 3527 // with a trivial copy constructor ([class.copy]) then the trait 3528 // is true, else it is false. 3529 if (T.isPODType(Self.Context) || T->isReferenceType()) 3530 return true; 3531 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 3532 return RD->hasTrivialCopyConstructor() && 3533 !RD->hasNonTrivialCopyConstructor(); 3534 return false; 3535 case UTT_HasTrivialMoveAssign: 3536 // This trait is implemented by MSVC 2012 and needed to parse the 3537 // standard library headers. Specifically it is used as the logic 3538 // behind std::is_trivially_move_assignable (20.9.4.3) 3539 if (T.isPODType(Self.Context)) 3540 return true; 3541 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) 3542 return RD->hasTrivialMoveAssignment() && !RD->hasNonTrivialMoveAssignment(); 3543 return false; 3544 case UTT_HasTrivialAssign: 3545 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3546 // If type is const qualified or is a reference type then the 3547 // trait is false. Otherwise if __is_pod (type) is true then the 3548 // trait is true, else if type is a cv class or union type with 3549 // a trivial copy assignment ([class.copy]) then the trait is 3550 // true, else it is false. 3551 // Note: the const and reference restrictions are interesting, 3552 // given that const and reference members don't prevent a class 3553 // from having a trivial copy assignment operator (but do cause 3554 // errors if the copy assignment operator is actually used, q.v. 3555 // [class.copy]p12). 3556 3557 if (T.isConstQualified()) 3558 return false; 3559 if (T.isPODType(Self.Context)) 3560 return true; 3561 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 3562 return RD->hasTrivialCopyAssignment() && 3563 !RD->hasNonTrivialCopyAssignment(); 3564 return false; 3565 case UTT_IsDestructible: 3566 case UTT_IsNothrowDestructible: 3567 // FIXME: Implement UTT_IsDestructible and UTT_IsNothrowDestructible. 3568 // For now, let's fall through. 3569 case UTT_HasTrivialDestructor: 3570 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html 3571 // If __is_pod (type) is true or type is a reference type 3572 // then the trait is true, else if type is a cv class or union 3573 // type (or array thereof) with a trivial destructor 3574 // ([class.dtor]) then the trait is true, else it is 3575 // false. 3576 if (T.isPODType(Self.Context) || T->isReferenceType()) 3577 return true; 3578 3579 // Objective-C++ ARC: autorelease types don't require destruction. 3580 if (T->isObjCLifetimeType() && 3581 T.getObjCLifetime() == Qualifiers::OCL_Autoreleasing) 3582 return true; 3583 3584 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) 3585 return RD->hasTrivialDestructor(); 3586 return false; 3587 // TODO: Propagate nothrowness for implicitly declared special members. 3588 case UTT_HasNothrowAssign: 3589 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3590 // If type is const qualified or is a reference type then the 3591 // trait is false. Otherwise if __has_trivial_assign (type) 3592 // is true then the trait is true, else if type is a cv class 3593 // or union type with copy assignment operators that are known 3594 // not to throw an exception then the trait is true, else it is 3595 // false. 3596 if (C.getBaseElementType(T).isConstQualified()) 3597 return false; 3598 if (T->isReferenceType()) 3599 return false; 3600 if (T.isPODType(Self.Context) || T->isObjCLifetimeType()) 3601 return true; 3602 3603 if (const RecordType *RT = T->getAs<RecordType>()) 3604 return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C, 3605 &CXXRecordDecl::hasTrivialCopyAssignment, 3606 &CXXRecordDecl::hasNonTrivialCopyAssignment, 3607 &CXXMethodDecl::isCopyAssignmentOperator); 3608 return false; 3609 case UTT_HasNothrowMoveAssign: 3610 // This trait is implemented by MSVC 2012 and needed to parse the 3611 // standard library headers. Specifically this is used as the logic 3612 // behind std::is_nothrow_move_assignable (20.9.4.3). 3613 if (T.isPODType(Self.Context)) 3614 return true; 3615 3616 if (const RecordType *RT = C.getBaseElementType(T)->getAs<RecordType>()) 3617 return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C, 3618 &CXXRecordDecl::hasTrivialMoveAssignment, 3619 &CXXRecordDecl::hasNonTrivialMoveAssignment, 3620 &CXXMethodDecl::isMoveAssignmentOperator); 3621 return false; 3622 case UTT_HasNothrowCopy: 3623 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3624 // If __has_trivial_copy (type) is true then the trait is true, else 3625 // if type is a cv class or union type with copy constructors that are 3626 // known not to throw an exception then the trait is true, else it is 3627 // false. 3628 if (T.isPODType(C) || T->isReferenceType() || T->isObjCLifetimeType()) 3629 return true; 3630 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) { 3631 if (RD->hasTrivialCopyConstructor() && 3632 !RD->hasNonTrivialCopyConstructor()) 3633 return true; 3634 3635 bool FoundConstructor = false; 3636 unsigned FoundTQs; 3637 DeclContext::lookup_result R = Self.LookupConstructors(RD); 3638 for (DeclContext::lookup_iterator Con = R.begin(), 3639 ConEnd = R.end(); Con != ConEnd; ++Con) { 3640 // A template constructor is never a copy constructor. 3641 // FIXME: However, it may actually be selected at the actual overload 3642 // resolution point. 3643 if (isa<FunctionTemplateDecl>(*Con)) 3644 continue; 3645 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con); 3646 if (Constructor->isCopyConstructor(FoundTQs)) { 3647 FoundConstructor = true; 3648 const FunctionProtoType *CPT 3649 = Constructor->getType()->getAs<FunctionProtoType>(); 3650 CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); 3651 if (!CPT) 3652 return false; 3653 // TODO: check whether evaluating default arguments can throw. 3654 // For now, we'll be conservative and assume that they can throw. 3655 if (!CPT->isNothrow(Self.Context) || CPT->getNumParams() > 1) 3656 return false; 3657 } 3658 } 3659 3660 return FoundConstructor; 3661 } 3662 return false; 3663 case UTT_HasNothrowConstructor: 3664 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html 3665 // If __has_trivial_constructor (type) is true then the trait is 3666 // true, else if type is a cv class or union type (or array 3667 // thereof) with a default constructor that is known not to 3668 // throw an exception then the trait is true, else it is false. 3669 if (T.isPODType(C) || T->isObjCLifetimeType()) 3670 return true; 3671 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) { 3672 if (RD->hasTrivialDefaultConstructor() && 3673 !RD->hasNonTrivialDefaultConstructor()) 3674 return true; 3675 3676 bool FoundConstructor = false; 3677 DeclContext::lookup_result R = Self.LookupConstructors(RD); 3678 for (DeclContext::lookup_iterator Con = R.begin(), 3679 ConEnd = R.end(); Con != ConEnd; ++Con) { 3680 // FIXME: In C++0x, a constructor template can be a default constructor. 3681 if (isa<FunctionTemplateDecl>(*Con)) 3682 continue; 3683 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con); 3684 if (Constructor->isDefaultConstructor()) { 3685 FoundConstructor = true; 3686 const FunctionProtoType *CPT 3687 = Constructor->getType()->getAs<FunctionProtoType>(); 3688 CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); 3689 if (!CPT) 3690 return false; 3691 // FIXME: check whether evaluating default arguments can throw. 3692 // For now, we'll be conservative and assume that they can throw. 3693 if (!CPT->isNothrow(Self.Context) || CPT->getNumParams() > 0) 3694 return false; 3695 } 3696 } 3697 return FoundConstructor; 3698 } 3699 return false; 3700 case UTT_HasVirtualDestructor: 3701 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3702 // If type is a class type with a virtual destructor ([class.dtor]) 3703 // then the trait is true, else it is false. 3704 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 3705 if (CXXDestructorDecl *Destructor = Self.LookupDestructor(RD)) 3706 return Destructor->isVirtual(); 3707 return false; 3708 3709 // These type trait expressions are modeled on the specifications for the 3710 // Embarcadero C++0x type trait functions: 3711 // http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index 3712 case UTT_IsCompleteType: 3713 // http://docwiki.embarcadero.com/RADStudio/XE/en/Is_complete_type_(typename_T_): 3714 // Returns True if and only if T is a complete type at the point of the 3715 // function call. 3716 return !T->isIncompleteType(); 3717 } 3718} 3719 3720/// \brief Determine whether T has a non-trivial Objective-C lifetime in 3721/// ARC mode. 3722static bool hasNontrivialObjCLifetime(QualType T) { 3723 switch (T.getObjCLifetime()) { 3724 case Qualifiers::OCL_ExplicitNone: 3725 return false; 3726 3727 case Qualifiers::OCL_Strong: 3728 case Qualifiers::OCL_Weak: 3729 case Qualifiers::OCL_Autoreleasing: 3730 return true; 3731 3732 case Qualifiers::OCL_None: 3733 return T->isObjCLifetimeType(); 3734 } 3735 3736 llvm_unreachable("Unknown ObjC lifetime qualifier"); 3737} 3738 3739static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT, 3740 QualType RhsT, SourceLocation KeyLoc); 3741 3742static bool evaluateTypeTrait(Sema &S, TypeTrait Kind, SourceLocation KWLoc, 3743 ArrayRef<TypeSourceInfo *> Args, 3744 SourceLocation RParenLoc) { 3745 if (Kind <= UTT_Last) 3746 return EvaluateUnaryTypeTrait(S, Kind, KWLoc, Args[0]->getType()); 3747 3748 if (Kind <= BTT_Last) 3749 return EvaluateBinaryTypeTrait(S, Kind, Args[0]->getType(), 3750 Args[1]->getType(), RParenLoc); 3751 3752 switch (Kind) { 3753 case clang::TT_IsConstructible: 3754 case clang::TT_IsNothrowConstructible: 3755 case clang::TT_IsTriviallyConstructible: { 3756 // C++11 [meta.unary.prop]: 3757 // is_trivially_constructible is defined as: 3758 // 3759 // is_constructible<T, Args...>::value is true and the variable 3760 // definition for is_constructible, as defined below, is known to call 3761 // no operation that is not trivial. 3762 // 3763 // The predicate condition for a template specialization 3764 // is_constructible<T, Args...> shall be satisfied if and only if the 3765 // following variable definition would be well-formed for some invented 3766 // variable t: 3767 // 3768 // T t(create<Args>()...); 3769 assert(!Args.empty()); 3770 3771 // Precondition: T and all types in the parameter pack Args shall be 3772 // complete types, (possibly cv-qualified) void, or arrays of 3773 // unknown bound. 3774 for (unsigned I = 0, N = Args.size(); I != N; ++I) { 3775 QualType ArgTy = Args[I]->getType(); 3776 if (ArgTy->isVoidType() || ArgTy->isIncompleteArrayType()) 3777 continue; 3778 3779 if (S.RequireCompleteType(KWLoc, ArgTy, 3780 diag::err_incomplete_type_used_in_type_trait_expr)) 3781 return false; 3782 } 3783 3784 // Make sure the first argument is a complete type. 3785 if (Args[0]->getType()->isIncompleteType()) 3786 return false; 3787 3788 // Make sure the first argument is not an abstract type. 3789 CXXRecordDecl *RD = Args[0]->getType()->getAsCXXRecordDecl(); 3790 if (RD && RD->isAbstract()) 3791 return false; 3792 3793 SmallVector<OpaqueValueExpr, 2> OpaqueArgExprs; 3794 SmallVector<Expr *, 2> ArgExprs; 3795 ArgExprs.reserve(Args.size() - 1); 3796 for (unsigned I = 1, N = Args.size(); I != N; ++I) { 3797 QualType T = Args[I]->getType(); 3798 if (T->isObjectType() || T->isFunctionType()) 3799 T = S.Context.getRValueReferenceType(T); 3800 OpaqueArgExprs.push_back( 3801 OpaqueValueExpr(Args[I]->getTypeLoc().getLocStart(), 3802 T.getNonLValueExprType(S.Context), 3803 Expr::getValueKindForType(T))); 3804 } 3805 for (Expr &E : OpaqueArgExprs) 3806 ArgExprs.push_back(&E); 3807 3808 // Perform the initialization in an unevaluated context within a SFINAE 3809 // trap at translation unit scope. 3810 EnterExpressionEvaluationContext Unevaluated(S, Sema::Unevaluated); 3811 Sema::SFINAETrap SFINAE(S, /*AccessCheckingSFINAE=*/true); 3812 Sema::ContextRAII TUContext(S, S.Context.getTranslationUnitDecl()); 3813 InitializedEntity To(InitializedEntity::InitializeTemporary(Args[0])); 3814 InitializationKind InitKind(InitializationKind::CreateDirect(KWLoc, KWLoc, 3815 RParenLoc)); 3816 InitializationSequence Init(S, To, InitKind, ArgExprs); 3817 if (Init.Failed()) 3818 return false; 3819 3820 ExprResult Result = Init.Perform(S, To, InitKind, ArgExprs); 3821 if (Result.isInvalid() || SFINAE.hasErrorOccurred()) 3822 return false; 3823 3824 if (Kind == clang::TT_IsConstructible) 3825 return true; 3826 3827 if (Kind == clang::TT_IsNothrowConstructible) 3828 return S.canThrow(Result.get()) == CT_Cannot; 3829 3830 if (Kind == clang::TT_IsTriviallyConstructible) { 3831 // Under Objective-C ARC, if the destination has non-trivial Objective-C 3832 // lifetime, this is a non-trivial construction. 3833 if (S.getLangOpts().ObjCAutoRefCount && 3834 hasNontrivialObjCLifetime(Args[0]->getType().getNonReferenceType())) 3835 return false; 3836 3837 // The initialization succeeded; now make sure there are no non-trivial 3838 // calls. 3839 return !Result.get()->hasNonTrivialCall(S.Context); 3840 } 3841 3842 llvm_unreachable("unhandled type trait"); 3843 return false; 3844 } 3845 default: llvm_unreachable("not a TT"); 3846 } 3847 3848 return false; 3849} 3850 3851ExprResult Sema::BuildTypeTrait(TypeTrait Kind, SourceLocation KWLoc, 3852 ArrayRef<TypeSourceInfo *> Args, 3853 SourceLocation RParenLoc) { 3854 QualType ResultType = Context.getLogicalOperationType(); 3855 3856 if (Kind <= UTT_Last && !CheckUnaryTypeTraitTypeCompleteness( 3857 *this, Kind, KWLoc, Args[0]->getType())) 3858 return ExprError(); 3859 3860 bool Dependent = false; 3861 for (unsigned I = 0, N = Args.size(); I != N; ++I) { 3862 if (Args[I]->getType()->isDependentType()) { 3863 Dependent = true; 3864 break; 3865 } 3866 } 3867 3868 bool Result = false; 3869 if (!Dependent) 3870 Result = evaluateTypeTrait(*this, Kind, KWLoc, Args, RParenLoc); 3871 3872 return TypeTraitExpr::Create(Context, ResultType, KWLoc, Kind, Args, 3873 RParenLoc, Result); 3874} 3875 3876ExprResult Sema::ActOnTypeTrait(TypeTrait Kind, SourceLocation KWLoc, 3877 ArrayRef<ParsedType> Args, 3878 SourceLocation RParenLoc) { 3879 SmallVector<TypeSourceInfo *, 4> ConvertedArgs; 3880 ConvertedArgs.reserve(Args.size()); 3881 3882 for (unsigned I = 0, N = Args.size(); I != N; ++I) { 3883 TypeSourceInfo *TInfo; 3884 QualType T = GetTypeFromParser(Args[I], &TInfo); 3885 if (!TInfo) 3886 TInfo = Context.getTrivialTypeSourceInfo(T, KWLoc); 3887 3888 ConvertedArgs.push_back(TInfo); 3889 } 3890 3891 return BuildTypeTrait(Kind, KWLoc, ConvertedArgs, RParenLoc); 3892} 3893 3894static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT, 3895 QualType RhsT, SourceLocation KeyLoc) { 3896 assert(!LhsT->isDependentType() && !RhsT->isDependentType() && 3897 "Cannot evaluate traits of dependent types"); 3898 3899 switch(BTT) { 3900 case BTT_IsBaseOf: { 3901 // C++0x [meta.rel]p2 3902 // Base is a base class of Derived without regard to cv-qualifiers or 3903 // Base and Derived are not unions and name the same class type without 3904 // regard to cv-qualifiers. 3905 3906 const RecordType *lhsRecord = LhsT->getAs<RecordType>(); 3907 if (!lhsRecord) return false; 3908 3909 const RecordType *rhsRecord = RhsT->getAs<RecordType>(); 3910 if (!rhsRecord) return false; 3911 3912 assert(Self.Context.hasSameUnqualifiedType(LhsT, RhsT) 3913 == (lhsRecord == rhsRecord)); 3914 3915 if (lhsRecord == rhsRecord) 3916 return !lhsRecord->getDecl()->isUnion(); 3917 3918 // C++0x [meta.rel]p2: 3919 // If Base and Derived are class types and are different types 3920 // (ignoring possible cv-qualifiers) then Derived shall be a 3921 // complete type. 3922 if (Self.RequireCompleteType(KeyLoc, RhsT, 3923 diag::err_incomplete_type_used_in_type_trait_expr)) 3924 return false; 3925 3926 return cast<CXXRecordDecl>(rhsRecord->getDecl()) 3927 ->isDerivedFrom(cast<CXXRecordDecl>(lhsRecord->getDecl())); 3928 } 3929 case BTT_IsSame: 3930 return Self.Context.hasSameType(LhsT, RhsT); 3931 case BTT_TypeCompatible: 3932 return Self.Context.typesAreCompatible(LhsT.getUnqualifiedType(), 3933 RhsT.getUnqualifiedType()); 3934 case BTT_IsConvertible: 3935 case BTT_IsConvertibleTo: { 3936 // C++0x [meta.rel]p4: 3937 // Given the following function prototype: 3938 // 3939 // template <class T> 3940 // typename add_rvalue_reference<T>::type create(); 3941 // 3942 // the predicate condition for a template specialization 3943 // is_convertible<From, To> shall be satisfied if and only if 3944 // the return expression in the following code would be 3945 // well-formed, including any implicit conversions to the return 3946 // type of the function: 3947 // 3948 // To test() { 3949 // return create<From>(); 3950 // } 3951 // 3952 // Access checking is performed as if in a context unrelated to To and 3953 // From. Only the validity of the immediate context of the expression 3954 // of the return-statement (including conversions to the return type) 3955 // is considered. 3956 // 3957 // We model the initialization as a copy-initialization of a temporary 3958 // of the appropriate type, which for this expression is identical to the 3959 // return statement (since NRVO doesn't apply). 3960 3961 // Functions aren't allowed to return function or array types. 3962 if (RhsT->isFunctionType() || RhsT->isArrayType()) 3963 return false; 3964 3965 // A return statement in a void function must have void type. 3966 if (RhsT->isVoidType()) 3967 return LhsT->isVoidType(); 3968 3969 // A function definition requires a complete, non-abstract return type. 3970 if (Self.RequireCompleteType(KeyLoc, RhsT, 0) || 3971 Self.RequireNonAbstractType(KeyLoc, RhsT, 0)) 3972 return false; 3973 3974 // Compute the result of add_rvalue_reference. 3975 if (LhsT->isObjectType() || LhsT->isFunctionType()) 3976 LhsT = Self.Context.getRValueReferenceType(LhsT); 3977 3978 // Build a fake source and destination for initialization. 3979 InitializedEntity To(InitializedEntity::InitializeTemporary(RhsT)); 3980 OpaqueValueExpr From(KeyLoc, LhsT.getNonLValueExprType(Self.Context), 3981 Expr::getValueKindForType(LhsT)); 3982 Expr *FromPtr = &From; 3983 InitializationKind Kind(InitializationKind::CreateCopy(KeyLoc, 3984 SourceLocation())); 3985 3986 // Perform the initialization in an unevaluated context within a SFINAE 3987 // trap at translation unit scope. 3988 EnterExpressionEvaluationContext Unevaluated(Self, Sema::Unevaluated); 3989 Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true); 3990 Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl()); 3991 InitializationSequence Init(Self, To, Kind, FromPtr); 3992 if (Init.Failed()) 3993 return false; 3994 3995 ExprResult Result = Init.Perform(Self, To, Kind, FromPtr); 3996 return !Result.isInvalid() && !SFINAE.hasErrorOccurred(); 3997 } 3998 3999 case BTT_IsNothrowAssignable: 4000 case BTT_IsTriviallyAssignable: { 4001 // C++11 [meta.unary.prop]p3: 4002 // is_trivially_assignable is defined as: 4003 // is_assignable<T, U>::value is true and the assignment, as defined by 4004 // is_assignable, is known to call no operation that is not trivial 4005 // 4006 // is_assignable is defined as: 4007 // The expression declval<T>() = declval<U>() is well-formed when 4008 // treated as an unevaluated operand (Clause 5). 4009 // 4010 // For both, T and U shall be complete types, (possibly cv-qualified) 4011 // void, or arrays of unknown bound. 4012 if (!LhsT->isVoidType() && !LhsT->isIncompleteArrayType() && 4013 Self.RequireCompleteType(KeyLoc, LhsT, 4014 diag::err_incomplete_type_used_in_type_trait_expr)) 4015 return false; 4016 if (!RhsT->isVoidType() && !RhsT->isIncompleteArrayType() && 4017 Self.RequireCompleteType(KeyLoc, RhsT, 4018 diag::err_incomplete_type_used_in_type_trait_expr)) 4019 return false; 4020 4021 // cv void is never assignable. 4022 if (LhsT->isVoidType() || RhsT->isVoidType()) 4023 return false; 4024 4025 // Build expressions that emulate the effect of declval<T>() and 4026 // declval<U>(). 4027 if (LhsT->isObjectType() || LhsT->isFunctionType()) 4028 LhsT = Self.Context.getRValueReferenceType(LhsT); 4029 if (RhsT->isObjectType() || RhsT->isFunctionType()) 4030 RhsT = Self.Context.getRValueReferenceType(RhsT); 4031 OpaqueValueExpr Lhs(KeyLoc, LhsT.getNonLValueExprType(Self.Context), 4032 Expr::getValueKindForType(LhsT)); 4033 OpaqueValueExpr Rhs(KeyLoc, RhsT.getNonLValueExprType(Self.Context), 4034 Expr::getValueKindForType(RhsT)); 4035 4036 // Attempt the assignment in an unevaluated context within a SFINAE 4037 // trap at translation unit scope. 4038 EnterExpressionEvaluationContext Unevaluated(Self, Sema::Unevaluated); 4039 Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true); 4040 Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl()); 4041 ExprResult Result = Self.BuildBinOp(/*S=*/nullptr, KeyLoc, BO_Assign, &Lhs, 4042 &Rhs); 4043 if (Result.isInvalid() || SFINAE.hasErrorOccurred()) 4044 return false; 4045 4046 if (BTT == BTT_IsNothrowAssignable) 4047 return Self.canThrow(Result.get()) == CT_Cannot; 4048 4049 if (BTT == BTT_IsTriviallyAssignable) { 4050 // Under Objective-C ARC, if the destination has non-trivial Objective-C 4051 // lifetime, this is a non-trivial assignment. 4052 if (Self.getLangOpts().ObjCAutoRefCount && 4053 hasNontrivialObjCLifetime(LhsT.getNonReferenceType())) 4054 return false; 4055 4056 return !Result.get()->hasNonTrivialCall(Self.Context); 4057 } 4058 4059 llvm_unreachable("unhandled type trait"); 4060 return false; 4061 } 4062 default: llvm_unreachable("not a BTT"); 4063 } 4064 llvm_unreachable("Unknown type trait or not implemented"); 4065} 4066 4067ExprResult Sema::ActOnArrayTypeTrait(ArrayTypeTrait ATT, 4068 SourceLocation KWLoc, 4069 ParsedType Ty, 4070 Expr* DimExpr, 4071 SourceLocation RParen) { 4072 TypeSourceInfo *TSInfo; 4073 QualType T = GetTypeFromParser(Ty, &TSInfo); 4074 if (!TSInfo) 4075 TSInfo = Context.getTrivialTypeSourceInfo(T); 4076 4077 return BuildArrayTypeTrait(ATT, KWLoc, TSInfo, DimExpr, RParen); 4078} 4079 4080static uint64_t EvaluateArrayTypeTrait(Sema &Self, ArrayTypeTrait ATT, 4081 QualType T, Expr *DimExpr, 4082 SourceLocation KeyLoc) { 4083 assert(!T->isDependentType() && "Cannot evaluate traits of dependent type"); 4084 4085 switch(ATT) { 4086 case ATT_ArrayRank: 4087 if (T->isArrayType()) { 4088 unsigned Dim = 0; 4089 while (const ArrayType *AT = Self.Context.getAsArrayType(T)) { 4090 ++Dim; 4091 T = AT->getElementType(); 4092 } 4093 return Dim; 4094 } 4095 return 0; 4096 4097 case ATT_ArrayExtent: { 4098 llvm::APSInt Value; 4099 uint64_t Dim; 4100 if (Self.VerifyIntegerConstantExpression(DimExpr, &Value, 4101 diag::err_dimension_expr_not_constant_integer, 4102 false).isInvalid()) 4103 return 0; 4104 if (Value.isSigned() && Value.isNegative()) { 4105 Self.Diag(KeyLoc, diag::err_dimension_expr_not_constant_integer) 4106 << DimExpr->getSourceRange(); 4107 return 0; 4108 } 4109 Dim = Value.getLimitedValue(); 4110 4111 if (T->isArrayType()) { 4112 unsigned D = 0; 4113 bool Matched = false; 4114 while (const ArrayType *AT = Self.Context.getAsArrayType(T)) { 4115 if (Dim == D) { 4116 Matched = true; 4117 break; 4118 } 4119 ++D; 4120 T = AT->getElementType(); 4121 } 4122 4123 if (Matched && T->isArrayType()) { 4124 if (const ConstantArrayType *CAT = Self.Context.getAsConstantArrayType(T)) 4125 return CAT->getSize().getLimitedValue(); 4126 } 4127 } 4128 return 0; 4129 } 4130 } 4131 llvm_unreachable("Unknown type trait or not implemented"); 4132} 4133 4134ExprResult Sema::BuildArrayTypeTrait(ArrayTypeTrait ATT, 4135 SourceLocation KWLoc, 4136 TypeSourceInfo *TSInfo, 4137 Expr* DimExpr, 4138 SourceLocation RParen) { 4139 QualType T = TSInfo->getType(); 4140 4141 // FIXME: This should likely be tracked as an APInt to remove any host 4142 // assumptions about the width of size_t on the target. 4143 uint64_t Value = 0; 4144 if (!T->isDependentType()) 4145 Value = EvaluateArrayTypeTrait(*this, ATT, T, DimExpr, KWLoc); 4146 4147 // While the specification for these traits from the Embarcadero C++ 4148 // compiler's documentation says the return type is 'unsigned int', Clang 4149 // returns 'size_t'. On Windows, the primary platform for the Embarcadero 4150 // compiler, there is no difference. On several other platforms this is an 4151 // important distinction. 4152 return new (Context) ArrayTypeTraitExpr(KWLoc, ATT, TSInfo, Value, DimExpr, 4153 RParen, Context.getSizeType()); 4154} 4155 4156ExprResult Sema::ActOnExpressionTrait(ExpressionTrait ET, 4157 SourceLocation KWLoc, 4158 Expr *Queried, 4159 SourceLocation RParen) { 4160 // If error parsing the expression, ignore. 4161 if (!Queried) 4162 return ExprError(); 4163 4164 ExprResult Result = BuildExpressionTrait(ET, KWLoc, Queried, RParen); 4165 4166 return Result; 4167} 4168 4169static bool EvaluateExpressionTrait(ExpressionTrait ET, Expr *E) { 4170 switch (ET) { 4171 case ET_IsLValueExpr: return E->isLValue(); 4172 case ET_IsRValueExpr: return E->isRValue(); 4173 } 4174 llvm_unreachable("Expression trait not covered by switch"); 4175} 4176 4177ExprResult Sema::BuildExpressionTrait(ExpressionTrait ET, 4178 SourceLocation KWLoc, 4179 Expr *Queried, 4180 SourceLocation RParen) { 4181 if (Queried->isTypeDependent()) { 4182 // Delay type-checking for type-dependent expressions. 4183 } else if (Queried->getType()->isPlaceholderType()) { 4184 ExprResult PE = CheckPlaceholderExpr(Queried); 4185 if (PE.isInvalid()) return ExprError(); 4186 return BuildExpressionTrait(ET, KWLoc, PE.get(), RParen); 4187 } 4188 4189 bool Value = EvaluateExpressionTrait(ET, Queried); 4190 4191 return new (Context) 4192 ExpressionTraitExpr(KWLoc, ET, Queried, Value, RParen, Context.BoolTy); 4193} 4194 4195QualType Sema::CheckPointerToMemberOperands(ExprResult &LHS, ExprResult &RHS, 4196 ExprValueKind &VK, 4197 SourceLocation Loc, 4198 bool isIndirect) { 4199 assert(!LHS.get()->getType()->isPlaceholderType() && 4200 !RHS.get()->getType()->isPlaceholderType() && 4201 "placeholders should have been weeded out by now"); 4202 4203 // The LHS undergoes lvalue conversions if this is ->*. 4204 if (isIndirect) { 4205 LHS = DefaultLvalueConversion(LHS.get()); 4206 if (LHS.isInvalid()) return QualType(); 4207 } 4208 4209 // The RHS always undergoes lvalue conversions. 4210 RHS = DefaultLvalueConversion(RHS.get()); 4211 if (RHS.isInvalid()) return QualType(); 4212 4213 const char *OpSpelling = isIndirect ? "->*" : ".*"; 4214 // C++ 5.5p2 4215 // The binary operator .* [p3: ->*] binds its second operand, which shall 4216 // be of type "pointer to member of T" (where T is a completely-defined 4217 // class type) [...] 4218 QualType RHSType = RHS.get()->getType(); 4219 const MemberPointerType *MemPtr = RHSType->getAs<MemberPointerType>(); 4220 if (!MemPtr) { 4221 Diag(Loc, diag::err_bad_memptr_rhs) 4222 << OpSpelling << RHSType << RHS.get()->getSourceRange(); 4223 return QualType(); 4224 } 4225 4226 QualType Class(MemPtr->getClass(), 0); 4227 4228 // Note: C++ [expr.mptr.oper]p2-3 says that the class type into which the 4229 // member pointer points must be completely-defined. However, there is no 4230 // reason for this semantic distinction, and the rule is not enforced by 4231 // other compilers. Therefore, we do not check this property, as it is 4232 // likely to be considered a defect. 4233 4234 // C++ 5.5p2 4235 // [...] to its first operand, which shall be of class T or of a class of 4236 // which T is an unambiguous and accessible base class. [p3: a pointer to 4237 // such a class] 4238 QualType LHSType = LHS.get()->getType(); 4239 if (isIndirect) { 4240 if (const PointerType *Ptr = LHSType->getAs<PointerType>()) 4241 LHSType = Ptr->getPointeeType(); 4242 else { 4243 Diag(Loc, diag::err_bad_memptr_lhs) 4244 << OpSpelling << 1 << LHSType 4245 << FixItHint::CreateReplacement(SourceRange(Loc), ".*"); 4246 return QualType(); 4247 } 4248 } 4249 4250 if (!Context.hasSameUnqualifiedType(Class, LHSType)) { 4251 // If we want to check the hierarchy, we need a complete type. 4252 if (RequireCompleteType(Loc, LHSType, diag::err_bad_memptr_lhs, 4253 OpSpelling, (int)isIndirect)) { 4254 return QualType(); 4255 } 4256 4257 if (!IsDerivedFrom(LHSType, Class)) { 4258 Diag(Loc, diag::err_bad_memptr_lhs) << OpSpelling 4259 << (int)isIndirect << LHS.get()->getType(); 4260 return QualType(); 4261 } 4262 4263 CXXCastPath BasePath; 4264 if (CheckDerivedToBaseConversion(LHSType, Class, Loc, 4265 SourceRange(LHS.get()->getLocStart(), 4266 RHS.get()->getLocEnd()), 4267 &BasePath)) 4268 return QualType(); 4269 4270 // Cast LHS to type of use. 4271 QualType UseType = isIndirect ? Context.getPointerType(Class) : Class; 4272 ExprValueKind VK = isIndirect ? VK_RValue : LHS.get()->getValueKind(); 4273 LHS = ImpCastExprToType(LHS.get(), UseType, CK_DerivedToBase, VK, 4274 &BasePath); 4275 } 4276 4277 if (isa<CXXScalarValueInitExpr>(RHS.get()->IgnoreParens())) { 4278 // Diagnose use of pointer-to-member type which when used as 4279 // the functional cast in a pointer-to-member expression. 4280 Diag(Loc, diag::err_pointer_to_member_type) << isIndirect; 4281 return QualType(); 4282 } 4283 4284 // C++ 5.5p2 4285 // The result is an object or a function of the type specified by the 4286 // second operand. 4287 // The cv qualifiers are the union of those in the pointer and the left side, 4288 // in accordance with 5.5p5 and 5.2.5. 4289 QualType Result = MemPtr->getPointeeType(); 4290 Result = Context.getCVRQualifiedType(Result, LHSType.getCVRQualifiers()); 4291 4292 // C++0x [expr.mptr.oper]p6: 4293 // In a .* expression whose object expression is an rvalue, the program is 4294 // ill-formed if the second operand is a pointer to member function with 4295 // ref-qualifier &. In a ->* expression or in a .* expression whose object 4296 // expression is an lvalue, the program is ill-formed if the second operand 4297 // is a pointer to member function with ref-qualifier &&. 4298 if (const FunctionProtoType *Proto = Result->getAs<FunctionProtoType>()) { 4299 switch (Proto->getRefQualifier()) { 4300 case RQ_None: 4301 // Do nothing 4302 break; 4303 4304 case RQ_LValue: 4305 if (!isIndirect && !LHS.get()->Classify(Context).isLValue()) 4306 Diag(Loc, diag::err_pointer_to_member_oper_value_classify) 4307 << RHSType << 1 << LHS.get()->getSourceRange(); 4308 break; 4309 4310 case RQ_RValue: 4311 if (isIndirect || !LHS.get()->Classify(Context).isRValue()) 4312 Diag(Loc, diag::err_pointer_to_member_oper_value_classify) 4313 << RHSType << 0 << LHS.get()->getSourceRange(); 4314 break; 4315 } 4316 } 4317 4318 // C++ [expr.mptr.oper]p6: 4319 // The result of a .* expression whose second operand is a pointer 4320 // to a data member is of the same value category as its 4321 // first operand. The result of a .* expression whose second 4322 // operand is a pointer to a member function is a prvalue. The 4323 // result of an ->* expression is an lvalue if its second operand 4324 // is a pointer to data member and a prvalue otherwise. 4325 if (Result->isFunctionType()) { 4326 VK = VK_RValue; 4327 return Context.BoundMemberTy; 4328 } else if (isIndirect) { 4329 VK = VK_LValue; 4330 } else { 4331 VK = LHS.get()->getValueKind(); 4332 } 4333 4334 return Result; 4335} 4336 4337/// \brief Try to convert a type to another according to C++0x 5.16p3. 4338/// 4339/// This is part of the parameter validation for the ? operator. If either 4340/// value operand is a class type, the two operands are attempted to be 4341/// converted to each other. This function does the conversion in one direction. 4342/// It returns true if the program is ill-formed and has already been diagnosed 4343/// as such. 4344static bool TryClassUnification(Sema &Self, Expr *From, Expr *To, 4345 SourceLocation QuestionLoc, 4346 bool &HaveConversion, 4347 QualType &ToType) { 4348 HaveConversion = false; 4349 ToType = To->getType(); 4350 4351 InitializationKind Kind = InitializationKind::CreateCopy(To->getLocStart(), 4352 SourceLocation()); 4353 // C++0x 5.16p3 4354 // The process for determining whether an operand expression E1 of type T1 4355 // can be converted to match an operand expression E2 of type T2 is defined 4356 // as follows: 4357 // -- If E2 is an lvalue: 4358 bool ToIsLvalue = To->isLValue(); 4359 if (ToIsLvalue) { 4360 // E1 can be converted to match E2 if E1 can be implicitly converted to 4361 // type "lvalue reference to T2", subject to the constraint that in the 4362 // conversion the reference must bind directly to E1. 4363 QualType T = Self.Context.getLValueReferenceType(ToType); 4364 InitializedEntity Entity = InitializedEntity::InitializeTemporary(T); 4365 4366 InitializationSequence InitSeq(Self, Entity, Kind, From); 4367 if (InitSeq.isDirectReferenceBinding()) { 4368 ToType = T; 4369 HaveConversion = true; 4370 return false; 4371 } 4372 4373 if (InitSeq.isAmbiguous()) 4374 return InitSeq.Diagnose(Self, Entity, Kind, From); 4375 } 4376 4377 // -- If E2 is an rvalue, or if the conversion above cannot be done: 4378 // -- if E1 and E2 have class type, and the underlying class types are 4379 // the same or one is a base class of the other: 4380 QualType FTy = From->getType(); 4381 QualType TTy = To->getType(); 4382 const RecordType *FRec = FTy->getAs<RecordType>(); 4383 const RecordType *TRec = TTy->getAs<RecordType>(); 4384 bool FDerivedFromT = FRec && TRec && FRec != TRec && 4385 Self.IsDerivedFrom(FTy, TTy); 4386 if (FRec && TRec && 4387 (FRec == TRec || FDerivedFromT || Self.IsDerivedFrom(TTy, FTy))) { 4388 // E1 can be converted to match E2 if the class of T2 is the 4389 // same type as, or a base class of, the class of T1, and 4390 // [cv2 > cv1]. 4391 if (FRec == TRec || FDerivedFromT) { 4392 if (TTy.isAtLeastAsQualifiedAs(FTy)) { 4393 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy); 4394 InitializationSequence InitSeq(Self, Entity, Kind, From); 4395 if (InitSeq) { 4396 HaveConversion = true; 4397 return false; 4398 } 4399 4400 if (InitSeq.isAmbiguous()) 4401 return InitSeq.Diagnose(Self, Entity, Kind, From); 4402 } 4403 } 4404 4405 return false; 4406 } 4407 4408 // -- Otherwise: E1 can be converted to match E2 if E1 can be 4409 // implicitly converted to the type that expression E2 would have 4410 // if E2 were converted to an rvalue (or the type it has, if E2 is 4411 // an rvalue). 4412 // 4413 // This actually refers very narrowly to the lvalue-to-rvalue conversion, not 4414 // to the array-to-pointer or function-to-pointer conversions. 4415 if (!TTy->getAs<TagType>()) 4416 TTy = TTy.getUnqualifiedType(); 4417 4418 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy); 4419 InitializationSequence InitSeq(Self, Entity, Kind, From); 4420 HaveConversion = !InitSeq.Failed(); 4421 ToType = TTy; 4422 if (InitSeq.isAmbiguous()) 4423 return InitSeq.Diagnose(Self, Entity, Kind, From); 4424 4425 return false; 4426} 4427 4428/// \brief Try to find a common type for two according to C++0x 5.16p5. 4429/// 4430/// This is part of the parameter validation for the ? operator. If either 4431/// value operand is a class type, overload resolution is used to find a 4432/// conversion to a common type. 4433static bool FindConditionalOverload(Sema &Self, ExprResult &LHS, ExprResult &RHS, 4434 SourceLocation QuestionLoc) { 4435 Expr *Args[2] = { LHS.get(), RHS.get() }; 4436 OverloadCandidateSet CandidateSet(QuestionLoc, 4437 OverloadCandidateSet::CSK_Operator); 4438 Self.AddBuiltinOperatorCandidates(OO_Conditional, QuestionLoc, Args, 4439 CandidateSet); 4440 4441 OverloadCandidateSet::iterator Best; 4442 switch (CandidateSet.BestViableFunction(Self, QuestionLoc, Best)) { 4443 case OR_Success: { 4444 // We found a match. Perform the conversions on the arguments and move on. 4445 ExprResult LHSRes = 4446 Self.PerformImplicitConversion(LHS.get(), Best->BuiltinTypes.ParamTypes[0], 4447 Best->Conversions[0], Sema::AA_Converting); 4448 if (LHSRes.isInvalid()) 4449 break; 4450 LHS = LHSRes; 4451 4452 ExprResult RHSRes = 4453 Self.PerformImplicitConversion(RHS.get(), Best->BuiltinTypes.ParamTypes[1], 4454 Best->Conversions[1], Sema::AA_Converting); 4455 if (RHSRes.isInvalid()) 4456 break; 4457 RHS = RHSRes; 4458 if (Best->Function) 4459 Self.MarkFunctionReferenced(QuestionLoc, Best->Function); 4460 return false; 4461 } 4462 4463 case OR_No_Viable_Function: 4464 4465 // Emit a better diagnostic if one of the expressions is a null pointer 4466 // constant and the other is a pointer type. In this case, the user most 4467 // likely forgot to take the address of the other expression. 4468 if (Self.DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc)) 4469 return true; 4470 4471 Self.Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4472 << LHS.get()->getType() << RHS.get()->getType() 4473 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 4474 return true; 4475 4476 case OR_Ambiguous: 4477 Self.Diag(QuestionLoc, diag::err_conditional_ambiguous_ovl) 4478 << LHS.get()->getType() << RHS.get()->getType() 4479 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 4480 // FIXME: Print the possible common types by printing the return types of 4481 // the viable candidates. 4482 break; 4483 4484 case OR_Deleted: 4485 llvm_unreachable("Conditional operator has only built-in overloads"); 4486 } 4487 return true; 4488} 4489 4490/// \brief Perform an "extended" implicit conversion as returned by 4491/// TryClassUnification. 4492static bool ConvertForConditional(Sema &Self, ExprResult &E, QualType T) { 4493 InitializedEntity Entity = InitializedEntity::InitializeTemporary(T); 4494 InitializationKind Kind = InitializationKind::CreateCopy(E.get()->getLocStart(), 4495 SourceLocation()); 4496 Expr *Arg = E.get(); 4497 InitializationSequence InitSeq(Self, Entity, Kind, Arg); 4498 ExprResult Result = InitSeq.Perform(Self, Entity, Kind, Arg); 4499 if (Result.isInvalid()) 4500 return true; 4501 4502 E = Result; 4503 return false; 4504} 4505 4506/// \brief Check the operands of ?: under C++ semantics. 4507/// 4508/// See C++ [expr.cond]. Note that LHS is never null, even for the GNU x ?: y 4509/// extension. In this case, LHS == Cond. (But they're not aliases.) 4510QualType Sema::CXXCheckConditionalOperands(ExprResult &Cond, ExprResult &LHS, 4511 ExprResult &RHS, ExprValueKind &VK, 4512 ExprObjectKind &OK, 4513 SourceLocation QuestionLoc) { 4514 // FIXME: Handle C99's complex types, vector types, block pointers and Obj-C++ 4515 // interface pointers. 4516 4517 // C++11 [expr.cond]p1 4518 // The first expression is contextually converted to bool. 4519 if (!Cond.get()->isTypeDependent()) { 4520 ExprResult CondRes = CheckCXXBooleanCondition(Cond.get()); 4521 if (CondRes.isInvalid()) 4522 return QualType(); 4523 Cond = CondRes; 4524 } 4525 4526 // Assume r-value. 4527 VK = VK_RValue; 4528 OK = OK_Ordinary; 4529 4530 // Either of the arguments dependent? 4531 if (LHS.get()->isTypeDependent() || RHS.get()->isTypeDependent()) 4532 return Context.DependentTy; 4533 4534 // C++11 [expr.cond]p2 4535 // If either the second or the third operand has type (cv) void, ... 4536 QualType LTy = LHS.get()->getType(); 4537 QualType RTy = RHS.get()->getType(); 4538 bool LVoid = LTy->isVoidType(); 4539 bool RVoid = RTy->isVoidType(); 4540 if (LVoid || RVoid) { 4541 // ... one of the following shall hold: 4542 // -- The second or the third operand (but not both) is a (possibly 4543 // parenthesized) throw-expression; the result is of the type 4544 // and value category of the other. 4545 bool LThrow = isa<CXXThrowExpr>(LHS.get()->IgnoreParenImpCasts()); 4546 bool RThrow = isa<CXXThrowExpr>(RHS.get()->IgnoreParenImpCasts()); 4547 if (LThrow != RThrow) { 4548 Expr *NonThrow = LThrow ? RHS.get() : LHS.get(); 4549 VK = NonThrow->getValueKind(); 4550 // DR (no number yet): the result is a bit-field if the 4551 // non-throw-expression operand is a bit-field. 4552 OK = NonThrow->getObjectKind(); 4553 return NonThrow->getType(); 4554 } 4555 4556 // -- Both the second and third operands have type void; the result is of 4557 // type void and is a prvalue. 4558 if (LVoid && RVoid) 4559 return Context.VoidTy; 4560 4561 // Neither holds, error. 4562 Diag(QuestionLoc, diag::err_conditional_void_nonvoid) 4563 << (LVoid ? RTy : LTy) << (LVoid ? 0 : 1) 4564 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 4565 return QualType(); 4566 } 4567 4568 // Neither is void. 4569 4570 // C++11 [expr.cond]p3 4571 // Otherwise, if the second and third operand have different types, and 4572 // either has (cv) class type [...] an attempt is made to convert each of 4573 // those operands to the type of the other. 4574 if (!Context.hasSameType(LTy, RTy) && 4575 (LTy->isRecordType() || RTy->isRecordType())) { 4576 // These return true if a single direction is already ambiguous. 4577 QualType L2RType, R2LType; 4578 bool HaveL2R, HaveR2L; 4579 if (TryClassUnification(*this, LHS.get(), RHS.get(), QuestionLoc, HaveL2R, L2RType)) 4580 return QualType(); 4581 if (TryClassUnification(*this, RHS.get(), LHS.get(), QuestionLoc, HaveR2L, R2LType)) 4582 return QualType(); 4583 4584 // If both can be converted, [...] the program is ill-formed. 4585 if (HaveL2R && HaveR2L) { 4586 Diag(QuestionLoc, diag::err_conditional_ambiguous) 4587 << LTy << RTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 4588 return QualType(); 4589 } 4590 4591 // If exactly one conversion is possible, that conversion is applied to 4592 // the chosen operand and the converted operands are used in place of the 4593 // original operands for the remainder of this section. 4594 if (HaveL2R) { 4595 if (ConvertForConditional(*this, LHS, L2RType) || LHS.isInvalid()) 4596 return QualType(); 4597 LTy = LHS.get()->getType(); 4598 } else if (HaveR2L) { 4599 if (ConvertForConditional(*this, RHS, R2LType) || RHS.isInvalid()) 4600 return QualType(); 4601 RTy = RHS.get()->getType(); 4602 } 4603 } 4604 4605 // C++11 [expr.cond]p3 4606 // if both are glvalues of the same value category and the same type except 4607 // for cv-qualification, an attempt is made to convert each of those 4608 // operands to the type of the other. 4609 ExprValueKind LVK = LHS.get()->getValueKind(); 4610 ExprValueKind RVK = RHS.get()->getValueKind(); 4611 if (!Context.hasSameType(LTy, RTy) && 4612 Context.hasSameUnqualifiedType(LTy, RTy) && 4613 LVK == RVK && LVK != VK_RValue) { 4614 // Since the unqualified types are reference-related and we require the 4615 // result to be as if a reference bound directly, the only conversion 4616 // we can perform is to add cv-qualifiers. 4617 Qualifiers LCVR = Qualifiers::fromCVRMask(LTy.getCVRQualifiers()); 4618 Qualifiers RCVR = Qualifiers::fromCVRMask(RTy.getCVRQualifiers()); 4619 if (RCVR.isStrictSupersetOf(LCVR)) { 4620 LHS = ImpCastExprToType(LHS.get(), RTy, CK_NoOp, LVK); 4621 LTy = LHS.get()->getType(); 4622 } 4623 else if (LCVR.isStrictSupersetOf(RCVR)) { 4624 RHS = ImpCastExprToType(RHS.get(), LTy, CK_NoOp, RVK); 4625 RTy = RHS.get()->getType(); 4626 } 4627 } 4628 4629 // C++11 [expr.cond]p4 4630 // If the second and third operands are glvalues of the same value 4631 // category and have the same type, the result is of that type and 4632 // value category and it is a bit-field if the second or the third 4633 // operand is a bit-field, or if both are bit-fields. 4634 // We only extend this to bitfields, not to the crazy other kinds of 4635 // l-values. 4636 bool Same = Context.hasSameType(LTy, RTy); 4637 if (Same && LVK == RVK && LVK != VK_RValue && 4638 LHS.get()->isOrdinaryOrBitFieldObject() && 4639 RHS.get()->isOrdinaryOrBitFieldObject()) { 4640 VK = LHS.get()->getValueKind(); 4641 if (LHS.get()->getObjectKind() == OK_BitField || 4642 RHS.get()->getObjectKind() == OK_BitField) 4643 OK = OK_BitField; 4644 return LTy; 4645 } 4646 4647 // C++11 [expr.cond]p5 4648 // Otherwise, the result is a prvalue. If the second and third operands 4649 // do not have the same type, and either has (cv) class type, ... 4650 if (!Same && (LTy->isRecordType() || RTy->isRecordType())) { 4651 // ... overload resolution is used to determine the conversions (if any) 4652 // to be applied to the operands. If the overload resolution fails, the 4653 // program is ill-formed. 4654 if (FindConditionalOverload(*this, LHS, RHS, QuestionLoc)) 4655 return QualType(); 4656 } 4657 4658 // C++11 [expr.cond]p6 4659 // Lvalue-to-rvalue, array-to-pointer, and function-to-pointer standard 4660 // conversions are performed on the second and third operands. 4661 LHS = DefaultFunctionArrayLvalueConversion(LHS.get()); 4662 RHS = DefaultFunctionArrayLvalueConversion(RHS.get()); 4663 if (LHS.isInvalid() || RHS.isInvalid()) 4664 return QualType(); 4665 LTy = LHS.get()->getType(); 4666 RTy = RHS.get()->getType(); 4667 4668 // After those conversions, one of the following shall hold: 4669 // -- The second and third operands have the same type; the result 4670 // is of that type. If the operands have class type, the result 4671 // is a prvalue temporary of the result type, which is 4672 // copy-initialized from either the second operand or the third 4673 // operand depending on the value of the first operand. 4674 if (Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy)) { 4675 if (LTy->isRecordType()) { 4676 // The operands have class type. Make a temporary copy. 4677 if (RequireNonAbstractType(QuestionLoc, LTy, 4678 diag::err_allocation_of_abstract_type)) 4679 return QualType(); 4680 InitializedEntity Entity = InitializedEntity::InitializeTemporary(LTy); 4681 4682 ExprResult LHSCopy = PerformCopyInitialization(Entity, 4683 SourceLocation(), 4684 LHS); 4685 if (LHSCopy.isInvalid()) 4686 return QualType(); 4687 4688 ExprResult RHSCopy = PerformCopyInitialization(Entity, 4689 SourceLocation(), 4690 RHS); 4691 if (RHSCopy.isInvalid()) 4692 return QualType(); 4693 4694 LHS = LHSCopy; 4695 RHS = RHSCopy; 4696 } 4697 4698 return LTy; 4699 } 4700 4701 // Extension: conditional operator involving vector types. 4702 if (LTy->isVectorType() || RTy->isVectorType()) 4703 return CheckVectorOperands(LHS, RHS, QuestionLoc, /*isCompAssign*/false); 4704 4705 // -- The second and third operands have arithmetic or enumeration type; 4706 // the usual arithmetic conversions are performed to bring them to a 4707 // common type, and the result is of that type. 4708 if (LTy->isArithmeticType() && RTy->isArithmeticType()) { 4709 QualType ResTy = UsualArithmeticConversions(LHS, RHS); 4710 if (LHS.isInvalid() || RHS.isInvalid()) 4711 return QualType(); 4712 4713 LHS = ImpCastExprToType(LHS.get(), ResTy, PrepareScalarCast(LHS, ResTy)); 4714 RHS = ImpCastExprToType(RHS.get(), ResTy, PrepareScalarCast(RHS, ResTy)); 4715 4716 return ResTy; 4717 } 4718 4719 // -- The second and third operands have pointer type, or one has pointer 4720 // type and the other is a null pointer constant, or both are null 4721 // pointer constants, at least one of which is non-integral; pointer 4722 // conversions and qualification conversions are performed to bring them 4723 // to their composite pointer type. The result is of the composite 4724 // pointer type. 4725 // -- The second and third operands have pointer to member type, or one has 4726 // pointer to member type and the other is a null pointer constant; 4727 // pointer to member conversions and qualification conversions are 4728 // performed to bring them to a common type, whose cv-qualification 4729 // shall match the cv-qualification of either the second or the third 4730 // operand. The result is of the common type. 4731 bool NonStandardCompositeType = false; 4732 QualType Composite = FindCompositePointerType(QuestionLoc, LHS, RHS, 4733 isSFINAEContext() ? nullptr 4734 : &NonStandardCompositeType); 4735 if (!Composite.isNull()) { 4736 if (NonStandardCompositeType) 4737 Diag(QuestionLoc, 4738 diag::ext_typecheck_cond_incompatible_operands_nonstandard) 4739 << LTy << RTy << Composite 4740 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 4741 4742 return Composite; 4743 } 4744 4745 // Similarly, attempt to find composite type of two objective-c pointers. 4746 Composite = FindCompositeObjCPointerType(LHS, RHS, QuestionLoc); 4747 if (!Composite.isNull()) 4748 return Composite; 4749 4750 // Check if we are using a null with a non-pointer type. 4751 if (DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc)) 4752 return QualType(); 4753 4754 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4755 << LHS.get()->getType() << RHS.get()->getType() 4756 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 4757 return QualType(); 4758} 4759 4760/// \brief Find a merged pointer type and convert the two expressions to it. 4761/// 4762/// This finds the composite pointer type (or member pointer type) for @p E1 4763/// and @p E2 according to C++11 5.9p2. It converts both expressions to this 4764/// type and returns it. 4765/// It does not emit diagnostics. 4766/// 4767/// \param Loc The location of the operator requiring these two expressions to 4768/// be converted to the composite pointer type. 4769/// 4770/// If \p NonStandardCompositeType is non-NULL, then we are permitted to find 4771/// a non-standard (but still sane) composite type to which both expressions 4772/// can be converted. When such a type is chosen, \c *NonStandardCompositeType 4773/// will be set true. 4774QualType Sema::FindCompositePointerType(SourceLocation Loc, 4775 Expr *&E1, Expr *&E2, 4776 bool *NonStandardCompositeType) { 4777 if (NonStandardCompositeType) 4778 *NonStandardCompositeType = false; 4779 4780 assert(getLangOpts().CPlusPlus && "This function assumes C++"); 4781 QualType T1 = E1->getType(), T2 = E2->getType(); 4782 4783 // C++11 5.9p2 4784 // Pointer conversions and qualification conversions are performed on 4785 // pointer operands to bring them to their composite pointer type. If 4786 // one operand is a null pointer constant, the composite pointer type is 4787 // std::nullptr_t if the other operand is also a null pointer constant or, 4788 // if the other operand is a pointer, the type of the other operand. 4789 if (!T1->isAnyPointerType() && !T1->isMemberPointerType() && 4790 !T2->isAnyPointerType() && !T2->isMemberPointerType()) { 4791 if (T1->isNullPtrType() && 4792 E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4793 E2 = ImpCastExprToType(E2, T1, CK_NullToPointer).get(); 4794 return T1; 4795 } 4796 if (T2->isNullPtrType() && 4797 E1->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4798 E1 = ImpCastExprToType(E1, T2, CK_NullToPointer).get(); 4799 return T2; 4800 } 4801 return QualType(); 4802 } 4803 4804 if (E1->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4805 if (T2->isMemberPointerType()) 4806 E1 = ImpCastExprToType(E1, T2, CK_NullToMemberPointer).get(); 4807 else 4808 E1 = ImpCastExprToType(E1, T2, CK_NullToPointer).get(); 4809 return T2; 4810 } 4811 if (E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4812 if (T1->isMemberPointerType()) 4813 E2 = ImpCastExprToType(E2, T1, CK_NullToMemberPointer).get(); 4814 else 4815 E2 = ImpCastExprToType(E2, T1, CK_NullToPointer).get(); 4816 return T1; 4817 } 4818 4819 // Now both have to be pointers or member pointers. 4820 if ((!T1->isPointerType() && !T1->isMemberPointerType()) || 4821 (!T2->isPointerType() && !T2->isMemberPointerType())) 4822 return QualType(); 4823 4824 // Otherwise, of one of the operands has type "pointer to cv1 void," then 4825 // the other has type "pointer to cv2 T" and the composite pointer type is 4826 // "pointer to cv12 void," where cv12 is the union of cv1 and cv2. 4827 // Otherwise, the composite pointer type is a pointer type similar to the 4828 // type of one of the operands, with a cv-qualification signature that is 4829 // the union of the cv-qualification signatures of the operand types. 4830 // In practice, the first part here is redundant; it's subsumed by the second. 4831 // What we do here is, we build the two possible composite types, and try the 4832 // conversions in both directions. If only one works, or if the two composite 4833 // types are the same, we have succeeded. 4834 // FIXME: extended qualifiers? 4835 typedef SmallVector<unsigned, 4> QualifierVector; 4836 QualifierVector QualifierUnion; 4837 typedef SmallVector<std::pair<const Type *, const Type *>, 4> 4838 ContainingClassVector; 4839 ContainingClassVector MemberOfClass; 4840 QualType Composite1 = Context.getCanonicalType(T1), 4841 Composite2 = Context.getCanonicalType(T2); 4842 unsigned NeedConstBefore = 0; 4843 do { 4844 const PointerType *Ptr1, *Ptr2; 4845 if ((Ptr1 = Composite1->getAs<PointerType>()) && 4846 (Ptr2 = Composite2->getAs<PointerType>())) { 4847 Composite1 = Ptr1->getPointeeType(); 4848 Composite2 = Ptr2->getPointeeType(); 4849 4850 // If we're allowed to create a non-standard composite type, keep track 4851 // of where we need to fill in additional 'const' qualifiers. 4852 if (NonStandardCompositeType && 4853 Composite1.getCVRQualifiers() != Composite2.getCVRQualifiers()) 4854 NeedConstBefore = QualifierUnion.size(); 4855 4856 QualifierUnion.push_back( 4857 Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers()); 4858 MemberOfClass.push_back(std::make_pair(nullptr, nullptr)); 4859 continue; 4860 } 4861 4862 const MemberPointerType *MemPtr1, *MemPtr2; 4863 if ((MemPtr1 = Composite1->getAs<MemberPointerType>()) && 4864 (MemPtr2 = Composite2->getAs<MemberPointerType>())) { 4865 Composite1 = MemPtr1->getPointeeType(); 4866 Composite2 = MemPtr2->getPointeeType(); 4867 4868 // If we're allowed to create a non-standard composite type, keep track 4869 // of where we need to fill in additional 'const' qualifiers. 4870 if (NonStandardCompositeType && 4871 Composite1.getCVRQualifiers() != Composite2.getCVRQualifiers()) 4872 NeedConstBefore = QualifierUnion.size(); 4873 4874 QualifierUnion.push_back( 4875 Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers()); 4876 MemberOfClass.push_back(std::make_pair(MemPtr1->getClass(), 4877 MemPtr2->getClass())); 4878 continue; 4879 } 4880 4881 // FIXME: block pointer types? 4882 4883 // Cannot unwrap any more types. 4884 break; 4885 } while (true); 4886 4887 if (NeedConstBefore && NonStandardCompositeType) { 4888 // Extension: Add 'const' to qualifiers that come before the first qualifier 4889 // mismatch, so that our (non-standard!) composite type meets the 4890 // requirements of C++ [conv.qual]p4 bullet 3. 4891 for (unsigned I = 0; I != NeedConstBefore; ++I) { 4892 if ((QualifierUnion[I] & Qualifiers::Const) == 0) { 4893 QualifierUnion[I] = QualifierUnion[I] | Qualifiers::Const; 4894 *NonStandardCompositeType = true; 4895 } 4896 } 4897 } 4898 4899 // Rewrap the composites as pointers or member pointers with the union CVRs. 4900 ContainingClassVector::reverse_iterator MOC 4901 = MemberOfClass.rbegin(); 4902 for (QualifierVector::reverse_iterator 4903 I = QualifierUnion.rbegin(), 4904 E = QualifierUnion.rend(); 4905 I != E; (void)++I, ++MOC) { 4906 Qualifiers Quals = Qualifiers::fromCVRMask(*I); 4907 if (MOC->first && MOC->second) { 4908 // Rebuild member pointer type 4909 Composite1 = Context.getMemberPointerType( 4910 Context.getQualifiedType(Composite1, Quals), 4911 MOC->first); 4912 Composite2 = Context.getMemberPointerType( 4913 Context.getQualifiedType(Composite2, Quals), 4914 MOC->second); 4915 } else { 4916 // Rebuild pointer type 4917 Composite1 4918 = Context.getPointerType(Context.getQualifiedType(Composite1, Quals)); 4919 Composite2 4920 = Context.getPointerType(Context.getQualifiedType(Composite2, Quals)); 4921 } 4922 } 4923 4924 // Try to convert to the first composite pointer type. 4925 InitializedEntity Entity1 4926 = InitializedEntity::InitializeTemporary(Composite1); 4927 InitializationKind Kind 4928 = InitializationKind::CreateCopy(Loc, SourceLocation()); 4929 InitializationSequence E1ToC1(*this, Entity1, Kind, E1); 4930 InitializationSequence E2ToC1(*this, Entity1, Kind, E2); 4931 4932 if (E1ToC1 && E2ToC1) { 4933 // Conversion to Composite1 is viable. 4934 if (!Context.hasSameType(Composite1, Composite2)) { 4935 // Composite2 is a different type from Composite1. Check whether 4936 // Composite2 is also viable. 4937 InitializedEntity Entity2 4938 = InitializedEntity::InitializeTemporary(Composite2); 4939 InitializationSequence E1ToC2(*this, Entity2, Kind, E1); 4940 InitializationSequence E2ToC2(*this, Entity2, Kind, E2); 4941 if (E1ToC2 && E2ToC2) { 4942 // Both Composite1 and Composite2 are viable and are different; 4943 // this is an ambiguity. 4944 return QualType(); 4945 } 4946 } 4947 4948 // Convert E1 to Composite1 4949 ExprResult E1Result 4950 = E1ToC1.Perform(*this, Entity1, Kind, E1); 4951 if (E1Result.isInvalid()) 4952 return QualType(); 4953 E1 = E1Result.getAs<Expr>(); 4954 4955 // Convert E2 to Composite1 4956 ExprResult E2Result 4957 = E2ToC1.Perform(*this, Entity1, Kind, E2); 4958 if (E2Result.isInvalid()) 4959 return QualType(); 4960 E2 = E2Result.getAs<Expr>(); 4961 4962 return Composite1; 4963 } 4964 4965 // Check whether Composite2 is viable. 4966 InitializedEntity Entity2 4967 = InitializedEntity::InitializeTemporary(Composite2); 4968 InitializationSequence E1ToC2(*this, Entity2, Kind, E1); 4969 InitializationSequence E2ToC2(*this, Entity2, Kind, E2); 4970 if (!E1ToC2 || !E2ToC2) 4971 return QualType(); 4972 4973 // Convert E1 to Composite2 4974 ExprResult E1Result 4975 = E1ToC2.Perform(*this, Entity2, Kind, E1); 4976 if (E1Result.isInvalid()) 4977 return QualType(); 4978 E1 = E1Result.getAs<Expr>(); 4979 4980 // Convert E2 to Composite2 4981 ExprResult E2Result 4982 = E2ToC2.Perform(*this, Entity2, Kind, E2); 4983 if (E2Result.isInvalid()) 4984 return QualType(); 4985 E2 = E2Result.getAs<Expr>(); 4986 4987 return Composite2; 4988} 4989 4990ExprResult Sema::MaybeBindToTemporary(Expr *E) { 4991 if (!E) 4992 return ExprError(); 4993 4994 assert(!isa<CXXBindTemporaryExpr>(E) && "Double-bound temporary?"); 4995 4996 // If the result is a glvalue, we shouldn't bind it. 4997 if (!E->isRValue()) 4998 return E; 4999 5000 // In ARC, calls that return a retainable type can return retained, 5001 // in which case we have to insert a consuming cast. 5002 if (getLangOpts().ObjCAutoRefCount && 5003 E->getType()->isObjCRetainableType()) { 5004 5005 bool ReturnsRetained; 5006 5007 // For actual calls, we compute this by examining the type of the 5008 // called value. 5009 if (CallExpr *Call = dyn_cast<CallExpr>(E)) { 5010 Expr *Callee = Call->getCallee()->IgnoreParens(); 5011 QualType T = Callee->getType(); 5012 5013 if (T == Context.BoundMemberTy) { 5014 // Handle pointer-to-members. 5015 if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(Callee)) 5016 T = BinOp->getRHS()->getType(); 5017 else if (MemberExpr *Mem = dyn_cast<MemberExpr>(Callee)) 5018 T = Mem->getMemberDecl()->getType(); 5019 } 5020 5021 if (const PointerType *Ptr = T->getAs<PointerType>()) 5022 T = Ptr->getPointeeType(); 5023 else if (const BlockPointerType *Ptr = T->getAs<BlockPointerType>()) 5024 T = Ptr->getPointeeType(); 5025 else if (const MemberPointerType *MemPtr = T->getAs<MemberPointerType>()) 5026 T = MemPtr->getPointeeType(); 5027 5028 const FunctionType *FTy = T->getAs<FunctionType>(); 5029 assert(FTy && "call to value not of function type?"); 5030 ReturnsRetained = FTy->getExtInfo().getProducesResult(); 5031 5032 // ActOnStmtExpr arranges things so that StmtExprs of retainable 5033 // type always produce a +1 object. 5034 } else if (isa<StmtExpr>(E)) { 5035 ReturnsRetained = true; 5036 5037 // We hit this case with the lambda conversion-to-block optimization; 5038 // we don't want any extra casts here. 5039 } else if (isa<CastExpr>(E) && 5040 isa<BlockExpr>(cast<CastExpr>(E)->getSubExpr())) { 5041 return E; 5042 5043 // For message sends and property references, we try to find an 5044 // actual method. FIXME: we should infer retention by selector in 5045 // cases where we don't have an actual method. 5046 } else { 5047 ObjCMethodDecl *D = nullptr; 5048 if (ObjCMessageExpr *Send = dyn_cast<ObjCMessageExpr>(E)) { 5049 D = Send->getMethodDecl(); 5050 } else if (ObjCBoxedExpr *BoxedExpr = dyn_cast<ObjCBoxedExpr>(E)) { 5051 D = BoxedExpr->getBoxingMethod(); 5052 } else if (ObjCArrayLiteral *ArrayLit = dyn_cast<ObjCArrayLiteral>(E)) { 5053 D = ArrayLit->getArrayWithObjectsMethod(); 5054 } else if (ObjCDictionaryLiteral *DictLit 5055 = dyn_cast<ObjCDictionaryLiteral>(E)) { 5056 D = DictLit->getDictWithObjectsMethod(); 5057 } 5058 5059 ReturnsRetained = (D && D->hasAttr<NSReturnsRetainedAttr>()); 5060 5061 // Don't do reclaims on performSelector calls; despite their 5062 // return type, the invoked method doesn't necessarily actually 5063 // return an object. 5064 if (!ReturnsRetained && 5065 D && D->getMethodFamily() == OMF_performSelector) 5066 return E; 5067 } 5068 5069 // Don't reclaim an object of Class type. 5070 if (!ReturnsRetained && E->getType()->isObjCARCImplicitlyUnretainedType()) 5071 return E; 5072 5073 ExprNeedsCleanups = true; 5074 5075 CastKind ck = (ReturnsRetained ? CK_ARCConsumeObject 5076 : CK_ARCReclaimReturnedObject); 5077 return ImplicitCastExpr::Create(Context, E->getType(), ck, E, nullptr, 5078 VK_RValue); 5079 } 5080 5081 if (!getLangOpts().CPlusPlus) 5082 return E; 5083 5084 // Search for the base element type (cf. ASTContext::getBaseElementType) with 5085 // a fast path for the common case that the type is directly a RecordType. 5086 const Type *T = Context.getCanonicalType(E->getType().getTypePtr()); 5087 const RecordType *RT = nullptr; 5088 while (!RT) { 5089 switch (T->getTypeClass()) { 5090 case Type::Record: 5091 RT = cast<RecordType>(T); 5092 break; 5093 case Type::ConstantArray: 5094 case Type::IncompleteArray: 5095 case Type::VariableArray: 5096 case Type::DependentSizedArray: 5097 T = cast<ArrayType>(T)->getElementType().getTypePtr(); 5098 break; 5099 default: 5100 return E; 5101 } 5102 } 5103 5104 // That should be enough to guarantee that this type is complete, if we're 5105 // not processing a decltype expression. 5106 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 5107 if (RD->isInvalidDecl() || RD->isDependentContext()) 5108 return E; 5109 5110 bool IsDecltype = ExprEvalContexts.back().IsDecltype; 5111 CXXDestructorDecl *Destructor = IsDecltype ? nullptr : LookupDestructor(RD); 5112 5113 if (Destructor) { 5114 MarkFunctionReferenced(E->getExprLoc(), Destructor); 5115 CheckDestructorAccess(E->getExprLoc(), Destructor, 5116 PDiag(diag::err_access_dtor_temp) 5117 << E->getType()); 5118 if (DiagnoseUseOfDecl(Destructor, E->getExprLoc())) 5119 return ExprError(); 5120 5121 // If destructor is trivial, we can avoid the extra copy. 5122 if (Destructor->isTrivial()) 5123 return E; 5124 5125 // We need a cleanup, but we don't need to remember the temporary. 5126 ExprNeedsCleanups = true; 5127 } 5128 5129 CXXTemporary *Temp = CXXTemporary::Create(Context, Destructor); 5130 CXXBindTemporaryExpr *Bind = CXXBindTemporaryExpr::Create(Context, Temp, E); 5131 5132 if (IsDecltype) 5133 ExprEvalContexts.back().DelayedDecltypeBinds.push_back(Bind); 5134 5135 return Bind; 5136} 5137 5138ExprResult 5139Sema::MaybeCreateExprWithCleanups(ExprResult SubExpr) { 5140 if (SubExpr.isInvalid()) 5141 return ExprError(); 5142 5143 return MaybeCreateExprWithCleanups(SubExpr.get()); 5144} 5145 5146Expr *Sema::MaybeCreateExprWithCleanups(Expr *SubExpr) { 5147 assert(SubExpr && "subexpression can't be null!"); 5148 5149 CleanupVarDeclMarking(); 5150 5151 unsigned FirstCleanup = ExprEvalContexts.back().NumCleanupObjects; 5152 assert(ExprCleanupObjects.size() >= FirstCleanup); 5153 assert(ExprNeedsCleanups || ExprCleanupObjects.size() == FirstCleanup); 5154 if (!ExprNeedsCleanups) 5155 return SubExpr; 5156 5157 auto Cleanups = llvm::makeArrayRef(ExprCleanupObjects.begin() + FirstCleanup, 5158 ExprCleanupObjects.size() - FirstCleanup); 5159 5160 Expr *E = ExprWithCleanups::Create(Context, SubExpr, Cleanups); 5161 DiscardCleanupsInEvaluationContext(); 5162 5163 return E; 5164} 5165 5166Stmt *Sema::MaybeCreateStmtWithCleanups(Stmt *SubStmt) { 5167 assert(SubStmt && "sub-statement can't be null!"); 5168 5169 CleanupVarDeclMarking(); 5170 5171 if (!ExprNeedsCleanups) 5172 return SubStmt; 5173 5174 // FIXME: In order to attach the temporaries, wrap the statement into 5175 // a StmtExpr; currently this is only used for asm statements. 5176 // This is hacky, either create a new CXXStmtWithTemporaries statement or 5177 // a new AsmStmtWithTemporaries. 5178 CompoundStmt *CompStmt = new (Context) CompoundStmt(Context, SubStmt, 5179 SourceLocation(), 5180 SourceLocation()); 5181 Expr *E = new (Context) StmtExpr(CompStmt, Context.VoidTy, SourceLocation(), 5182 SourceLocation()); 5183 return MaybeCreateExprWithCleanups(E); 5184} 5185 5186/// Process the expression contained within a decltype. For such expressions, 5187/// certain semantic checks on temporaries are delayed until this point, and 5188/// are omitted for the 'topmost' call in the decltype expression. If the 5189/// topmost call bound a temporary, strip that temporary off the expression. 5190ExprResult Sema::ActOnDecltypeExpression(Expr *E) { 5191 assert(ExprEvalContexts.back().IsDecltype && "not in a decltype expression"); 5192 5193 // C++11 [expr.call]p11: 5194 // If a function call is a prvalue of object type, 5195 // -- if the function call is either 5196 // -- the operand of a decltype-specifier, or 5197 // -- the right operand of a comma operator that is the operand of a 5198 // decltype-specifier, 5199 // a temporary object is not introduced for the prvalue. 5200 5201 // Recursively rebuild ParenExprs and comma expressions to strip out the 5202 // outermost CXXBindTemporaryExpr, if any. 5203 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 5204 ExprResult SubExpr = ActOnDecltypeExpression(PE->getSubExpr()); 5205 if (SubExpr.isInvalid()) 5206 return ExprError(); 5207 if (SubExpr.get() == PE->getSubExpr()) 5208 return E; 5209 return ActOnParenExpr(PE->getLParen(), PE->getRParen(), SubExpr.get()); 5210 } 5211 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) { 5212 if (BO->getOpcode() == BO_Comma) { 5213 ExprResult RHS = ActOnDecltypeExpression(BO->getRHS()); 5214 if (RHS.isInvalid()) 5215 return ExprError(); 5216 if (RHS.get() == BO->getRHS()) 5217 return E; 5218 return new (Context) BinaryOperator( 5219 BO->getLHS(), RHS.get(), BO_Comma, BO->getType(), BO->getValueKind(), 5220 BO->getObjectKind(), BO->getOperatorLoc(), BO->isFPContractable()); 5221 } 5222 } 5223 5224 CXXBindTemporaryExpr *TopBind = dyn_cast<CXXBindTemporaryExpr>(E); 5225 CallExpr *TopCall = TopBind ? dyn_cast<CallExpr>(TopBind->getSubExpr()) 5226 : nullptr; 5227 if (TopCall) 5228 E = TopCall; 5229 else 5230 TopBind = nullptr; 5231 5232 // Disable the special decltype handling now. 5233 ExprEvalContexts.back().IsDecltype = false; 5234 5235 // In MS mode, don't perform any extra checking of call return types within a 5236 // decltype expression. 5237 if (getLangOpts().MSVCCompat) 5238 return E; 5239 5240 // Perform the semantic checks we delayed until this point. 5241 for (unsigned I = 0, N = ExprEvalContexts.back().DelayedDecltypeCalls.size(); 5242 I != N; ++I) { 5243 CallExpr *Call = ExprEvalContexts.back().DelayedDecltypeCalls[I]; 5244 if (Call == TopCall) 5245 continue; 5246 5247 if (CheckCallReturnType(Call->getCallReturnType(Context), 5248 Call->getLocStart(), 5249 Call, Call->getDirectCallee())) 5250 return ExprError(); 5251 } 5252 5253 // Now all relevant types are complete, check the destructors are accessible 5254 // and non-deleted, and annotate them on the temporaries. 5255 for (unsigned I = 0, N = ExprEvalContexts.back().DelayedDecltypeBinds.size(); 5256 I != N; ++I) { 5257 CXXBindTemporaryExpr *Bind = 5258 ExprEvalContexts.back().DelayedDecltypeBinds[I]; 5259 if (Bind == TopBind) 5260 continue; 5261 5262 CXXTemporary *Temp = Bind->getTemporary(); 5263 5264 CXXRecordDecl *RD = 5265 Bind->getType()->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); 5266 CXXDestructorDecl *Destructor = LookupDestructor(RD); 5267 Temp->setDestructor(Destructor); 5268 5269 MarkFunctionReferenced(Bind->getExprLoc(), Destructor); 5270 CheckDestructorAccess(Bind->getExprLoc(), Destructor, 5271 PDiag(diag::err_access_dtor_temp) 5272 << Bind->getType()); 5273 if (DiagnoseUseOfDecl(Destructor, Bind->getExprLoc())) 5274 return ExprError(); 5275 5276 // We need a cleanup, but we don't need to remember the temporary. 5277 ExprNeedsCleanups = true; 5278 } 5279 5280 // Possibly strip off the top CXXBindTemporaryExpr. 5281 return E; 5282} 5283 5284/// Note a set of 'operator->' functions that were used for a member access. 5285static void noteOperatorArrows(Sema &S, 5286 ArrayRef<FunctionDecl *> OperatorArrows) { 5287 unsigned SkipStart = OperatorArrows.size(), SkipCount = 0; 5288 // FIXME: Make this configurable? 5289 unsigned Limit = 9; 5290 if (OperatorArrows.size() > Limit) { 5291 // Produce Limit-1 normal notes and one 'skipping' note. 5292 SkipStart = (Limit - 1) / 2 + (Limit - 1) % 2; 5293 SkipCount = OperatorArrows.size() - (Limit - 1); 5294 } 5295 5296 for (unsigned I = 0; I < OperatorArrows.size(); /**/) { 5297 if (I == SkipStart) { 5298 S.Diag(OperatorArrows[I]->getLocation(), 5299 diag::note_operator_arrows_suppressed) 5300 << SkipCount; 5301 I += SkipCount; 5302 } else { 5303 S.Diag(OperatorArrows[I]->getLocation(), diag::note_operator_arrow_here) 5304 << OperatorArrows[I]->getCallResultType(); 5305 ++I; 5306 } 5307 } 5308} 5309 5310ExprResult Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base, 5311 SourceLocation OpLoc, 5312 tok::TokenKind OpKind, 5313 ParsedType &ObjectType, 5314 bool &MayBePseudoDestructor) { 5315 // Since this might be a postfix expression, get rid of ParenListExprs. 5316 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base); 5317 if (Result.isInvalid()) return ExprError(); 5318 Base = Result.get(); 5319 5320 Result = CheckPlaceholderExpr(Base); 5321 if (Result.isInvalid()) return ExprError(); 5322 Base = Result.get(); 5323 5324 QualType BaseType = Base->getType(); 5325 MayBePseudoDestructor = false; 5326 if (BaseType->isDependentType()) { 5327 // If we have a pointer to a dependent type and are using the -> operator, 5328 // the object type is the type that the pointer points to. We might still 5329 // have enough information about that type to do something useful. 5330 if (OpKind == tok::arrow) 5331 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) 5332 BaseType = Ptr->getPointeeType(); 5333 5334 ObjectType = ParsedType::make(BaseType); 5335 MayBePseudoDestructor = true; 5336 return Base; 5337 } 5338 5339 // C++ [over.match.oper]p8: 5340 // [...] When operator->returns, the operator-> is applied to the value 5341 // returned, with the original second operand. 5342 if (OpKind == tok::arrow) { 5343 QualType StartingType = BaseType; 5344 bool NoArrowOperatorFound = false; 5345 bool FirstIteration = true; 5346 FunctionDecl *CurFD = dyn_cast<FunctionDecl>(CurContext); 5347 // The set of types we've considered so far. 5348 llvm::SmallPtrSet<CanQualType,8> CTypes; 5349 SmallVector<FunctionDecl*, 8> OperatorArrows; 5350 CTypes.insert(Context.getCanonicalType(BaseType)); 5351 5352 while (BaseType->isRecordType()) { 5353 if (OperatorArrows.size() >= getLangOpts().ArrowDepth) { 5354 Diag(OpLoc, diag::err_operator_arrow_depth_exceeded) 5355 << StartingType << getLangOpts().ArrowDepth << Base->getSourceRange(); 5356 noteOperatorArrows(*this, OperatorArrows); 5357 Diag(OpLoc, diag::note_operator_arrow_depth) 5358 << getLangOpts().ArrowDepth; 5359 return ExprError(); 5360 } 5361 5362 Result = BuildOverloadedArrowExpr( 5363 S, Base, OpLoc, 5364 // When in a template specialization and on the first loop iteration, 5365 // potentially give the default diagnostic (with the fixit in a 5366 // separate note) instead of having the error reported back to here 5367 // and giving a diagnostic with a fixit attached to the error itself. 5368 (FirstIteration && CurFD && CurFD->isFunctionTemplateSpecialization()) 5369 ? nullptr 5370 : &NoArrowOperatorFound); 5371 if (Result.isInvalid()) { 5372 if (NoArrowOperatorFound) { 5373 if (FirstIteration) { 5374 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 5375 << BaseType << 1 << Base->getSourceRange() 5376 << FixItHint::CreateReplacement(OpLoc, "."); 5377 OpKind = tok::period; 5378 break; 5379 } 5380 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 5381 << BaseType << Base->getSourceRange(); 5382 CallExpr *CE = dyn_cast<CallExpr>(Base); 5383 if (Decl *CD = (CE ? CE->getCalleeDecl() : nullptr)) { 5384 Diag(CD->getLocStart(), 5385 diag::note_member_reference_arrow_from_operator_arrow); 5386 } 5387 } 5388 return ExprError(); 5389 } 5390 Base = Result.get(); 5391 if (CXXOperatorCallExpr *OpCall = dyn_cast<CXXOperatorCallExpr>(Base)) 5392 OperatorArrows.push_back(OpCall->getDirectCallee()); 5393 BaseType = Base->getType(); 5394 CanQualType CBaseType = Context.getCanonicalType(BaseType); 5395 if (!CTypes.insert(CBaseType).second) { 5396 Diag(OpLoc, diag::err_operator_arrow_circular) << StartingType; 5397 noteOperatorArrows(*this, OperatorArrows); 5398 return ExprError(); 5399 } 5400 FirstIteration = false; 5401 } 5402 5403 if (OpKind == tok::arrow && 5404 (BaseType->isPointerType() || BaseType->isObjCObjectPointerType())) 5405 BaseType = BaseType->getPointeeType(); 5406 } 5407 5408 // Objective-C properties allow "." access on Objective-C pointer types, 5409 // so adjust the base type to the object type itself. 5410 if (BaseType->isObjCObjectPointerType()) 5411 BaseType = BaseType->getPointeeType(); 5412 5413 // C++ [basic.lookup.classref]p2: 5414 // [...] If the type of the object expression is of pointer to scalar 5415 // type, the unqualified-id is looked up in the context of the complete 5416 // postfix-expression. 5417 // 5418 // This also indicates that we could be parsing a pseudo-destructor-name. 5419 // Note that Objective-C class and object types can be pseudo-destructor 5420 // expressions or normal member (ivar or property) access expressions. 5421 if (BaseType->isObjCObjectOrInterfaceType()) { 5422 MayBePseudoDestructor = true; 5423 } else if (!BaseType->isRecordType()) { 5424 ObjectType = ParsedType(); 5425 MayBePseudoDestructor = true; 5426 return Base; 5427 } 5428 5429 // The object type must be complete (or dependent), or 5430 // C++11 [expr.prim.general]p3: 5431 // Unlike the object expression in other contexts, *this is not required to 5432 // be of complete type for purposes of class member access (5.2.5) outside 5433 // the member function body. 5434 if (!BaseType->isDependentType() && 5435 !isThisOutsideMemberFunctionBody(BaseType) && 5436 RequireCompleteType(OpLoc, BaseType, diag::err_incomplete_member_access)) 5437 return ExprError(); 5438 5439 // C++ [basic.lookup.classref]p2: 5440 // If the id-expression in a class member access (5.2.5) is an 5441 // unqualified-id, and the type of the object expression is of a class 5442 // type C (or of pointer to a class type C), the unqualified-id is looked 5443 // up in the scope of class C. [...] 5444 ObjectType = ParsedType::make(BaseType); 5445 return Base; 5446} 5447 5448static bool CheckArrow(Sema& S, QualType& ObjectType, Expr *&Base, 5449 tok::TokenKind& OpKind, SourceLocation OpLoc) { 5450 if (Base->hasPlaceholderType()) { 5451 ExprResult result = S.CheckPlaceholderExpr(Base); 5452 if (result.isInvalid()) return true; 5453 Base = result.get(); 5454 } 5455 ObjectType = Base->getType(); 5456 5457 // C++ [expr.pseudo]p2: 5458 // The left-hand side of the dot operator shall be of scalar type. The 5459 // left-hand side of the arrow operator shall be of pointer to scalar type. 5460 // This scalar type is the object type. 5461 // Note that this is rather different from the normal handling for the 5462 // arrow operator. 5463 if (OpKind == tok::arrow) { 5464 if (const PointerType *Ptr = ObjectType->getAs<PointerType>()) { 5465 ObjectType = Ptr->getPointeeType(); 5466 } else if (!Base->isTypeDependent()) { 5467 // The user wrote "p->" when she probably meant "p."; fix it. 5468 S.Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 5469 << ObjectType << true 5470 << FixItHint::CreateReplacement(OpLoc, "."); 5471 if (S.isSFINAEContext()) 5472 return true; 5473 5474 OpKind = tok::period; 5475 } 5476 } 5477 5478 return false; 5479} 5480 5481ExprResult Sema::BuildPseudoDestructorExpr(Expr *Base, 5482 SourceLocation OpLoc, 5483 tok::TokenKind OpKind, 5484 const CXXScopeSpec &SS, 5485 TypeSourceInfo *ScopeTypeInfo, 5486 SourceLocation CCLoc, 5487 SourceLocation TildeLoc, 5488 PseudoDestructorTypeStorage Destructed) { 5489 TypeSourceInfo *DestructedTypeInfo = Destructed.getTypeSourceInfo(); 5490 5491 QualType ObjectType; 5492 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) 5493 return ExprError(); 5494 5495 if (!ObjectType->isDependentType() && !ObjectType->isScalarType() && 5496 !ObjectType->isVectorType()) { 5497 if (getLangOpts().MSVCCompat && ObjectType->isVoidType()) 5498 Diag(OpLoc, diag::ext_pseudo_dtor_on_void) << Base->getSourceRange(); 5499 else { 5500 Diag(OpLoc, diag::err_pseudo_dtor_base_not_scalar) 5501 << ObjectType << Base->getSourceRange(); 5502 return ExprError(); 5503 } 5504 } 5505 5506 // C++ [expr.pseudo]p2: 5507 // [...] The cv-unqualified versions of the object type and of the type 5508 // designated by the pseudo-destructor-name shall be the same type. 5509 if (DestructedTypeInfo) { 5510 QualType DestructedType = DestructedTypeInfo->getType(); 5511 SourceLocation DestructedTypeStart 5512 = DestructedTypeInfo->getTypeLoc().getLocalSourceRange().getBegin(); 5513 if (!DestructedType->isDependentType() && !ObjectType->isDependentType()) { 5514 if (!Context.hasSameUnqualifiedType(DestructedType, ObjectType)) { 5515 Diag(DestructedTypeStart, diag::err_pseudo_dtor_type_mismatch) 5516 << ObjectType << DestructedType << Base->getSourceRange() 5517 << DestructedTypeInfo->getTypeLoc().getLocalSourceRange(); 5518 5519 // Recover by setting the destructed type to the object type. 5520 DestructedType = ObjectType; 5521 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(ObjectType, 5522 DestructedTypeStart); 5523 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); 5524 } else if (DestructedType.getObjCLifetime() != 5525 ObjectType.getObjCLifetime()) { 5526 5527 if (DestructedType.getObjCLifetime() == Qualifiers::OCL_None) { 5528 // Okay: just pretend that the user provided the correctly-qualified 5529 // type. 5530 } else { 5531 Diag(DestructedTypeStart, diag::err_arc_pseudo_dtor_inconstant_quals) 5532 << ObjectType << DestructedType << Base->getSourceRange() 5533 << DestructedTypeInfo->getTypeLoc().getLocalSourceRange(); 5534 } 5535 5536 // Recover by setting the destructed type to the object type. 5537 DestructedType = ObjectType; 5538 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(ObjectType, 5539 DestructedTypeStart); 5540 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); 5541 } 5542 } 5543 } 5544 5545 // C++ [expr.pseudo]p2: 5546 // [...] Furthermore, the two type-names in a pseudo-destructor-name of the 5547 // form 5548 // 5549 // ::[opt] nested-name-specifier[opt] type-name :: ~ type-name 5550 // 5551 // shall designate the same scalar type. 5552 if (ScopeTypeInfo) { 5553 QualType ScopeType = ScopeTypeInfo->getType(); 5554 if (!ScopeType->isDependentType() && !ObjectType->isDependentType() && 5555 !Context.hasSameUnqualifiedType(ScopeType, ObjectType)) { 5556 5557 Diag(ScopeTypeInfo->getTypeLoc().getLocalSourceRange().getBegin(), 5558 diag::err_pseudo_dtor_type_mismatch) 5559 << ObjectType << ScopeType << Base->getSourceRange() 5560 << ScopeTypeInfo->getTypeLoc().getLocalSourceRange(); 5561 5562 ScopeType = QualType(); 5563 ScopeTypeInfo = nullptr; 5564 } 5565 } 5566 5567 Expr *Result 5568 = new (Context) CXXPseudoDestructorExpr(Context, Base, 5569 OpKind == tok::arrow, OpLoc, 5570 SS.getWithLocInContext(Context), 5571 ScopeTypeInfo, 5572 CCLoc, 5573 TildeLoc, 5574 Destructed); 5575 5576 return Result; 5577} 5578 5579ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base, 5580 SourceLocation OpLoc, 5581 tok::TokenKind OpKind, 5582 CXXScopeSpec &SS, 5583 UnqualifiedId &FirstTypeName, 5584 SourceLocation CCLoc, 5585 SourceLocation TildeLoc, 5586 UnqualifiedId &SecondTypeName) { 5587 assert((FirstTypeName.getKind() == UnqualifiedId::IK_TemplateId || 5588 FirstTypeName.getKind() == UnqualifiedId::IK_Identifier) && 5589 "Invalid first type name in pseudo-destructor"); 5590 assert((SecondTypeName.getKind() == UnqualifiedId::IK_TemplateId || 5591 SecondTypeName.getKind() == UnqualifiedId::IK_Identifier) && 5592 "Invalid second type name in pseudo-destructor"); 5593 5594 QualType ObjectType; 5595 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) 5596 return ExprError(); 5597 5598 // Compute the object type that we should use for name lookup purposes. Only 5599 // record types and dependent types matter. 5600 ParsedType ObjectTypePtrForLookup; 5601 if (!SS.isSet()) { 5602 if (ObjectType->isRecordType()) 5603 ObjectTypePtrForLookup = ParsedType::make(ObjectType); 5604 else if (ObjectType->isDependentType()) 5605 ObjectTypePtrForLookup = ParsedType::make(Context.DependentTy); 5606 } 5607 5608 // Convert the name of the type being destructed (following the ~) into a 5609 // type (with source-location information). 5610 QualType DestructedType; 5611 TypeSourceInfo *DestructedTypeInfo = nullptr; 5612 PseudoDestructorTypeStorage Destructed; 5613 if (SecondTypeName.getKind() == UnqualifiedId::IK_Identifier) { 5614 ParsedType T = getTypeName(*SecondTypeName.Identifier, 5615 SecondTypeName.StartLocation, 5616 S, &SS, true, false, ObjectTypePtrForLookup); 5617 if (!T && 5618 ((SS.isSet() && !computeDeclContext(SS, false)) || 5619 (!SS.isSet() && ObjectType->isDependentType()))) { 5620 // The name of the type being destroyed is a dependent name, and we 5621 // couldn't find anything useful in scope. Just store the identifier and 5622 // it's location, and we'll perform (qualified) name lookup again at 5623 // template instantiation time. 5624 Destructed = PseudoDestructorTypeStorage(SecondTypeName.Identifier, 5625 SecondTypeName.StartLocation); 5626 } else if (!T) { 5627 Diag(SecondTypeName.StartLocation, 5628 diag::err_pseudo_dtor_destructor_non_type) 5629 << SecondTypeName.Identifier << ObjectType; 5630 if (isSFINAEContext()) 5631 return ExprError(); 5632 5633 // Recover by assuming we had the right type all along. 5634 DestructedType = ObjectType; 5635 } else 5636 DestructedType = GetTypeFromParser(T, &DestructedTypeInfo); 5637 } else { 5638 // Resolve the template-id to a type. 5639 TemplateIdAnnotation *TemplateId = SecondTypeName.TemplateId; 5640 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(), 5641 TemplateId->NumArgs); 5642 TypeResult T = ActOnTemplateIdType(TemplateId->SS, 5643 TemplateId->TemplateKWLoc, 5644 TemplateId->Template, 5645 TemplateId->TemplateNameLoc, 5646 TemplateId->LAngleLoc, 5647 TemplateArgsPtr, 5648 TemplateId->RAngleLoc); 5649 if (T.isInvalid() || !T.get()) { 5650 // Recover by assuming we had the right type all along. 5651 DestructedType = ObjectType; 5652 } else 5653 DestructedType = GetTypeFromParser(T.get(), &DestructedTypeInfo); 5654 } 5655 5656 // If we've performed some kind of recovery, (re-)build the type source 5657 // information. 5658 if (!DestructedType.isNull()) { 5659 if (!DestructedTypeInfo) 5660 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(DestructedType, 5661 SecondTypeName.StartLocation); 5662 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); 5663 } 5664 5665 // Convert the name of the scope type (the type prior to '::') into a type. 5666 TypeSourceInfo *ScopeTypeInfo = nullptr; 5667 QualType ScopeType; 5668 if (FirstTypeName.getKind() == UnqualifiedId::IK_TemplateId || 5669 FirstTypeName.Identifier) { 5670 if (FirstTypeName.getKind() == UnqualifiedId::IK_Identifier) { 5671 ParsedType T = getTypeName(*FirstTypeName.Identifier, 5672 FirstTypeName.StartLocation, 5673 S, &SS, true, false, ObjectTypePtrForLookup); 5674 if (!T) { 5675 Diag(FirstTypeName.StartLocation, 5676 diag::err_pseudo_dtor_destructor_non_type) 5677 << FirstTypeName.Identifier << ObjectType; 5678 5679 if (isSFINAEContext()) 5680 return ExprError(); 5681 5682 // Just drop this type. It's unnecessary anyway. 5683 ScopeType = QualType(); 5684 } else 5685 ScopeType = GetTypeFromParser(T, &ScopeTypeInfo); 5686 } else { 5687 // Resolve the template-id to a type. 5688 TemplateIdAnnotation *TemplateId = FirstTypeName.TemplateId; 5689 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(), 5690 TemplateId->NumArgs); 5691 TypeResult T = ActOnTemplateIdType(TemplateId->SS, 5692 TemplateId->TemplateKWLoc, 5693 TemplateId->Template, 5694 TemplateId->TemplateNameLoc, 5695 TemplateId->LAngleLoc, 5696 TemplateArgsPtr, 5697 TemplateId->RAngleLoc); 5698 if (T.isInvalid() || !T.get()) { 5699 // Recover by dropping this type. 5700 ScopeType = QualType(); 5701 } else 5702 ScopeType = GetTypeFromParser(T.get(), &ScopeTypeInfo); 5703 } 5704 } 5705 5706 if (!ScopeType.isNull() && !ScopeTypeInfo) 5707 ScopeTypeInfo = Context.getTrivialTypeSourceInfo(ScopeType, 5708 FirstTypeName.StartLocation); 5709 5710 5711 return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, SS, 5712 ScopeTypeInfo, CCLoc, TildeLoc, 5713 Destructed); 5714} 5715 5716ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base, 5717 SourceLocation OpLoc, 5718 tok::TokenKind OpKind, 5719 SourceLocation TildeLoc, 5720 const DeclSpec& DS) { 5721 QualType ObjectType; 5722 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) 5723 return ExprError(); 5724 5725 QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc(), 5726 false); 5727 5728 TypeLocBuilder TLB; 5729 DecltypeTypeLoc DecltypeTL = TLB.push<DecltypeTypeLoc>(T); 5730 DecltypeTL.setNameLoc(DS.getTypeSpecTypeLoc()); 5731 TypeSourceInfo *DestructedTypeInfo = TLB.getTypeSourceInfo(Context, T); 5732 PseudoDestructorTypeStorage Destructed(DestructedTypeInfo); 5733 5734 return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, CXXScopeSpec(), 5735 nullptr, SourceLocation(), TildeLoc, 5736 Destructed); 5737} 5738 5739ExprResult Sema::BuildCXXMemberCallExpr(Expr *E, NamedDecl *FoundDecl, 5740 CXXConversionDecl *Method, 5741 bool HadMultipleCandidates) { 5742 if (Method->getParent()->isLambda() && 5743 Method->getConversionType()->isBlockPointerType()) { 5744 // This is a lambda coversion to block pointer; check if the argument 5745 // is a LambdaExpr. 5746 Expr *SubE = E; 5747 CastExpr *CE = dyn_cast<CastExpr>(SubE); 5748 if (CE && CE->getCastKind() == CK_NoOp) 5749 SubE = CE->getSubExpr(); 5750 SubE = SubE->IgnoreParens(); 5751 if (CXXBindTemporaryExpr *BE = dyn_cast<CXXBindTemporaryExpr>(SubE)) 5752 SubE = BE->getSubExpr(); 5753 if (isa<LambdaExpr>(SubE)) { 5754 // For the conversion to block pointer on a lambda expression, we 5755 // construct a special BlockLiteral instead; this doesn't really make 5756 // a difference in ARC, but outside of ARC the resulting block literal 5757 // follows the normal lifetime rules for block literals instead of being 5758 // autoreleased. 5759 DiagnosticErrorTrap Trap(Diags); 5760 ExprResult Exp = BuildBlockForLambdaConversion(E->getExprLoc(), 5761 E->getExprLoc(), 5762 Method, E); 5763 if (Exp.isInvalid()) 5764 Diag(E->getExprLoc(), diag::note_lambda_to_block_conv); 5765 return Exp; 5766 } 5767 } 5768 5769 ExprResult Exp = PerformObjectArgumentInitialization(E, /*Qualifier=*/nullptr, 5770 FoundDecl, Method); 5771 if (Exp.isInvalid()) 5772 return true; 5773 5774 MemberExpr *ME = new (Context) MemberExpr( 5775 Exp.get(), /*IsArrow=*/false, SourceLocation(), Method, SourceLocation(), 5776 Context.BoundMemberTy, VK_RValue, OK_Ordinary); 5777 if (HadMultipleCandidates) 5778 ME->setHadMultipleCandidates(true); 5779 MarkMemberReferenced(ME); 5780 5781 QualType ResultType = Method->getReturnType(); 5782 ExprValueKind VK = Expr::getValueKindForType(ResultType); 5783 ResultType = ResultType.getNonLValueExprType(Context); 5784 5785 CXXMemberCallExpr *CE = 5786 new (Context) CXXMemberCallExpr(Context, ME, None, ResultType, VK, 5787 Exp.get()->getLocEnd()); 5788 return CE; 5789} 5790 5791ExprResult Sema::BuildCXXNoexceptExpr(SourceLocation KeyLoc, Expr *Operand, 5792 SourceLocation RParen) { 5793 if (ActiveTemplateInstantiations.empty() && 5794 Operand->HasSideEffects(Context, false)) { 5795 // The expression operand for noexcept is in an unevaluated expression 5796 // context, so side effects could result in unintended consequences. 5797 Diag(Operand->getExprLoc(), diag::warn_side_effects_unevaluated_context); 5798 } 5799 5800 CanThrowResult CanThrow = canThrow(Operand); 5801 return new (Context) 5802 CXXNoexceptExpr(Context.BoolTy, Operand, CanThrow, KeyLoc, RParen); 5803} 5804 5805ExprResult Sema::ActOnNoexceptExpr(SourceLocation KeyLoc, SourceLocation, 5806 Expr *Operand, SourceLocation RParen) { 5807 return BuildCXXNoexceptExpr(KeyLoc, Operand, RParen); 5808} 5809 5810static bool IsSpecialDiscardedValue(Expr *E) { 5811 // In C++11, discarded-value expressions of a certain form are special, 5812 // according to [expr]p10: 5813 // The lvalue-to-rvalue conversion (4.1) is applied only if the 5814 // expression is an lvalue of volatile-qualified type and it has 5815 // one of the following forms: 5816 E = E->IgnoreParens(); 5817 5818 // - id-expression (5.1.1), 5819 if (isa<DeclRefExpr>(E)) 5820 return true; 5821 5822 // - subscripting (5.2.1), 5823 if (isa<ArraySubscriptExpr>(E)) 5824 return true; 5825 5826 // - class member access (5.2.5), 5827 if (isa<MemberExpr>(E)) 5828 return true; 5829 5830 // - indirection (5.3.1), 5831 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) 5832 if (UO->getOpcode() == UO_Deref) 5833 return true; 5834 5835 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) { 5836 // - pointer-to-member operation (5.5), 5837 if (BO->isPtrMemOp()) 5838 return true; 5839 5840 // - comma expression (5.18) where the right operand is one of the above. 5841 if (BO->getOpcode() == BO_Comma) 5842 return IsSpecialDiscardedValue(BO->getRHS()); 5843 } 5844 5845 // - conditional expression (5.16) where both the second and the third 5846 // operands are one of the above, or 5847 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) 5848 return IsSpecialDiscardedValue(CO->getTrueExpr()) && 5849 IsSpecialDiscardedValue(CO->getFalseExpr()); 5850 // The related edge case of "*x ?: *x". 5851 if (BinaryConditionalOperator *BCO = 5852 dyn_cast<BinaryConditionalOperator>(E)) { 5853 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(BCO->getTrueExpr())) 5854 return IsSpecialDiscardedValue(OVE->getSourceExpr()) && 5855 IsSpecialDiscardedValue(BCO->getFalseExpr()); 5856 } 5857 5858 // Objective-C++ extensions to the rule. 5859 if (isa<PseudoObjectExpr>(E) || isa<ObjCIvarRefExpr>(E)) 5860 return true; 5861 5862 return false; 5863} 5864 5865/// Perform the conversions required for an expression used in a 5866/// context that ignores the result. 5867ExprResult Sema::IgnoredValueConversions(Expr *E) { 5868 if (E->hasPlaceholderType()) { 5869 ExprResult result = CheckPlaceholderExpr(E); 5870 if (result.isInvalid()) return E; 5871 E = result.get(); 5872 } 5873 5874 // C99 6.3.2.1: 5875 // [Except in specific positions,] an lvalue that does not have 5876 // array type is converted to the value stored in the 5877 // designated object (and is no longer an lvalue). 5878 if (E->isRValue()) { 5879 // In C, function designators (i.e. expressions of function type) 5880 // are r-values, but we still want to do function-to-pointer decay 5881 // on them. This is both technically correct and convenient for 5882 // some clients. 5883 if (!getLangOpts().CPlusPlus && E->getType()->isFunctionType()) 5884 return DefaultFunctionArrayConversion(E); 5885 5886 return E; 5887 } 5888 5889 if (getLangOpts().CPlusPlus) { 5890 // The C++11 standard defines the notion of a discarded-value expression; 5891 // normally, we don't need to do anything to handle it, but if it is a 5892 // volatile lvalue with a special form, we perform an lvalue-to-rvalue 5893 // conversion. 5894 if (getLangOpts().CPlusPlus11 && E->isGLValue() && 5895 E->getType().isVolatileQualified() && 5896 IsSpecialDiscardedValue(E)) { 5897 ExprResult Res = DefaultLvalueConversion(E); 5898 if (Res.isInvalid()) 5899 return E; 5900 E = Res.get(); 5901 } 5902 return E; 5903 } 5904 5905 // GCC seems to also exclude expressions of incomplete enum type. 5906 if (const EnumType *T = E->getType()->getAs<EnumType>()) { 5907 if (!T->getDecl()->isComplete()) { 5908 // FIXME: stupid workaround for a codegen bug! 5909 E = ImpCastExprToType(E, Context.VoidTy, CK_ToVoid).get(); 5910 return E; 5911 } 5912 } 5913 5914 ExprResult Res = DefaultFunctionArrayLvalueConversion(E); 5915 if (Res.isInvalid()) 5916 return E; 5917 E = Res.get(); 5918 5919 if (!E->getType()->isVoidType()) 5920 RequireCompleteType(E->getExprLoc(), E->getType(), 5921 diag::err_incomplete_type); 5922 return E; 5923} 5924 5925// If we can unambiguously determine whether Var can never be used 5926// in a constant expression, return true. 5927// - if the variable and its initializer are non-dependent, then 5928// we can unambiguously check if the variable is a constant expression. 5929// - if the initializer is not value dependent - we can determine whether 5930// it can be used to initialize a constant expression. If Init can not 5931// be used to initialize a constant expression we conclude that Var can 5932// never be a constant expression. 5933// - FXIME: if the initializer is dependent, we can still do some analysis and 5934// identify certain cases unambiguously as non-const by using a Visitor: 5935// - such as those that involve odr-use of a ParmVarDecl, involve a new 5936// delete, lambda-expr, dynamic-cast, reinterpret-cast etc... 5937static inline bool VariableCanNeverBeAConstantExpression(VarDecl *Var, 5938 ASTContext &Context) { 5939 if (isa<ParmVarDecl>(Var)) return true; 5940 const VarDecl *DefVD = nullptr; 5941 5942 // If there is no initializer - this can not be a constant expression. 5943 if (!Var->getAnyInitializer(DefVD)) return true; 5944 assert(DefVD); 5945 if (DefVD->isWeak()) return false; 5946 EvaluatedStmt *Eval = DefVD->ensureEvaluatedStmt(); 5947 5948 Expr *Init = cast<Expr>(Eval->Value); 5949 5950 if (Var->getType()->isDependentType() || Init->isValueDependent()) { 5951 // FIXME: Teach the constant evaluator to deal with the non-dependent parts 5952 // of value-dependent expressions, and use it here to determine whether the 5953 // initializer is a potential constant expression. 5954 return false; 5955 } 5956 5957 return !IsVariableAConstantExpression(Var, Context); 5958} 5959 5960/// \brief Check if the current lambda has any potential captures 5961/// that must be captured by any of its enclosing lambdas that are ready to 5962/// capture. If there is a lambda that can capture a nested 5963/// potential-capture, go ahead and do so. Also, check to see if any 5964/// variables are uncaptureable or do not involve an odr-use so do not 5965/// need to be captured. 5966 5967static void CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures( 5968 Expr *const FE, LambdaScopeInfo *const CurrentLSI, Sema &S) { 5969 5970 assert(!S.isUnevaluatedContext()); 5971 assert(S.CurContext->isDependentContext()); 5972 assert(CurrentLSI->CallOperator == S.CurContext && 5973 "The current call operator must be synchronized with Sema's CurContext"); 5974 5975 const bool IsFullExprInstantiationDependent = FE->isInstantiationDependent(); 5976 5977 ArrayRef<const FunctionScopeInfo *> FunctionScopesArrayRef( 5978 S.FunctionScopes.data(), S.FunctionScopes.size()); 5979 5980 // All the potentially captureable variables in the current nested 5981 // lambda (within a generic outer lambda), must be captured by an 5982 // outer lambda that is enclosed within a non-dependent context. 5983 const unsigned NumPotentialCaptures = 5984 CurrentLSI->getNumPotentialVariableCaptures(); 5985 for (unsigned I = 0; I != NumPotentialCaptures; ++I) { 5986 Expr *VarExpr = nullptr; 5987 VarDecl *Var = nullptr; 5988 CurrentLSI->getPotentialVariableCapture(I, Var, VarExpr); 5989 // If the variable is clearly identified as non-odr-used and the full 5990 // expression is not instantiation dependent, only then do we not 5991 // need to check enclosing lambda's for speculative captures. 5992 // For e.g.: 5993 // Even though 'x' is not odr-used, it should be captured. 5994 // int test() { 5995 // const int x = 10; 5996 // auto L = [=](auto a) { 5997 // (void) +x + a; 5998 // }; 5999 // } 6000 if (CurrentLSI->isVariableExprMarkedAsNonODRUsed(VarExpr) && 6001 !IsFullExprInstantiationDependent) 6002 continue; 6003 6004 // If we have a capture-capable lambda for the variable, go ahead and 6005 // capture the variable in that lambda (and all its enclosing lambdas). 6006 if (const Optional<unsigned> Index = 6007 getStackIndexOfNearestEnclosingCaptureCapableLambda( 6008 FunctionScopesArrayRef, Var, S)) { 6009 const unsigned FunctionScopeIndexOfCapturableLambda = Index.getValue(); 6010 MarkVarDeclODRUsed(Var, VarExpr->getExprLoc(), S, 6011 &FunctionScopeIndexOfCapturableLambda); 6012 } 6013 const bool IsVarNeverAConstantExpression = 6014 VariableCanNeverBeAConstantExpression(Var, S.Context); 6015 if (!IsFullExprInstantiationDependent || IsVarNeverAConstantExpression) { 6016 // This full expression is not instantiation dependent or the variable 6017 // can not be used in a constant expression - which means 6018 // this variable must be odr-used here, so diagnose a 6019 // capture violation early, if the variable is un-captureable. 6020 // This is purely for diagnosing errors early. Otherwise, this 6021 // error would get diagnosed when the lambda becomes capture ready. 6022 QualType CaptureType, DeclRefType; 6023 SourceLocation ExprLoc = VarExpr->getExprLoc(); 6024 if (S.tryCaptureVariable(Var, ExprLoc, S.TryCapture_Implicit, 6025 /*EllipsisLoc*/ SourceLocation(), 6026 /*BuildAndDiagnose*/false, CaptureType, 6027 DeclRefType, nullptr)) { 6028 // We will never be able to capture this variable, and we need 6029 // to be able to in any and all instantiations, so diagnose it. 6030 S.tryCaptureVariable(Var, ExprLoc, S.TryCapture_Implicit, 6031 /*EllipsisLoc*/ SourceLocation(), 6032 /*BuildAndDiagnose*/true, CaptureType, 6033 DeclRefType, nullptr); 6034 } 6035 } 6036 } 6037 6038 // Check if 'this' needs to be captured. 6039 if (CurrentLSI->hasPotentialThisCapture()) { 6040 // If we have a capture-capable lambda for 'this', go ahead and capture 6041 // 'this' in that lambda (and all its enclosing lambdas). 6042 if (const Optional<unsigned> Index = 6043 getStackIndexOfNearestEnclosingCaptureCapableLambda( 6044 FunctionScopesArrayRef, /*0 is 'this'*/ nullptr, S)) { 6045 const unsigned FunctionScopeIndexOfCapturableLambda = Index.getValue(); 6046 S.CheckCXXThisCapture(CurrentLSI->PotentialThisCaptureLocation, 6047 /*Explicit*/ false, /*BuildAndDiagnose*/ true, 6048 &FunctionScopeIndexOfCapturableLambda); 6049 } 6050 } 6051 6052 // Reset all the potential captures at the end of each full-expression. 6053 CurrentLSI->clearPotentialCaptures(); 6054} 6055 6056static ExprResult attemptRecovery(Sema &SemaRef, 6057 const TypoCorrectionConsumer &Consumer, 6058 TypoCorrection TC) { 6059 LookupResult R(SemaRef, Consumer.getLookupResult().getLookupNameInfo(), 6060 Consumer.getLookupResult().getLookupKind()); 6061 const CXXScopeSpec *SS = Consumer.getSS(); 6062 CXXScopeSpec NewSS; 6063 6064 // Use an approprate CXXScopeSpec for building the expr. 6065 if (auto *NNS = TC.getCorrectionSpecifier()) 6066 NewSS.MakeTrivial(SemaRef.Context, NNS, TC.getCorrectionRange()); 6067 else if (SS && !TC.WillReplaceSpecifier()) 6068 NewSS = *SS; 6069 6070 if (auto *ND = TC.getCorrectionDecl()) { 6071 R.setLookupName(ND->getDeclName()); 6072 R.addDecl(ND); 6073 if (ND->isCXXClassMember()) { 6074 // Figure out the correct naming class to add to the LookupResult. 6075 CXXRecordDecl *Record = nullptr; 6076 if (auto *NNS = TC.getCorrectionSpecifier()) 6077 Record = NNS->getAsType()->getAsCXXRecordDecl(); 6078 if (!Record) 6079 Record = 6080 dyn_cast<CXXRecordDecl>(ND->getDeclContext()->getRedeclContext()); 6081 if (Record) 6082 R.setNamingClass(Record); 6083 6084 // Detect and handle the case where the decl might be an implicit 6085 // member. 6086 bool MightBeImplicitMember; 6087 if (!Consumer.isAddressOfOperand()) 6088 MightBeImplicitMember = true; 6089 else if (!NewSS.isEmpty()) 6090 MightBeImplicitMember = false; 6091 else if (R.isOverloadedResult()) 6092 MightBeImplicitMember = false; 6093 else if (R.isUnresolvableResult()) 6094 MightBeImplicitMember = true; 6095 else 6096 MightBeImplicitMember = isa<FieldDecl>(ND) || 6097 isa<IndirectFieldDecl>(ND) || 6098 isa<MSPropertyDecl>(ND); 6099 6100 if (MightBeImplicitMember) 6101 return SemaRef.BuildPossibleImplicitMemberExpr( 6102 NewSS, /*TemplateKWLoc*/ SourceLocation(), R, 6103 /*TemplateArgs*/ nullptr); 6104 } else if (auto *Ivar = dyn_cast<ObjCIvarDecl>(ND)) { 6105 return SemaRef.LookupInObjCMethod(R, Consumer.getScope(), 6106 Ivar->getIdentifier()); 6107 } 6108 } 6109 6110 return SemaRef.BuildDeclarationNameExpr(NewSS, R, /*NeedsADL*/ false, 6111 /*AcceptInvalidDecl*/ true); 6112} 6113 6114namespace { 6115class FindTypoExprs : public RecursiveASTVisitor<FindTypoExprs> { 6116 llvm::SmallSetVector<TypoExpr *, 2> &TypoExprs; 6117 6118public: 6119 explicit FindTypoExprs(llvm::SmallSetVector<TypoExpr *, 2> &TypoExprs) 6120 : TypoExprs(TypoExprs) {} 6121 bool VisitTypoExpr(TypoExpr *TE) { 6122 TypoExprs.insert(TE); 6123 return true; 6124 } 6125}; 6126 6127class TransformTypos : public TreeTransform<TransformTypos> { 6128 typedef TreeTransform<TransformTypos> BaseTransform; 6129 6130 llvm::function_ref<ExprResult(Expr *)> ExprFilter; 6131 llvm::SmallSetVector<TypoExpr *, 2> TypoExprs, AmbiguousTypoExprs; 6132 llvm::SmallDenseMap<TypoExpr *, ExprResult, 2> TransformCache; 6133 llvm::SmallDenseMap<OverloadExpr *, Expr *, 4> OverloadResolution; 6134 6135 /// \brief Emit diagnostics for all of the TypoExprs encountered. 6136 /// If the TypoExprs were successfully corrected, then the diagnostics should 6137 /// suggest the corrections. Otherwise the diagnostics will not suggest 6138 /// anything (having been passed an empty TypoCorrection). 6139 void EmitAllDiagnostics() { 6140 for (auto E : TypoExprs) { 6141 TypoExpr *TE = cast<TypoExpr>(E); 6142 auto &State = SemaRef.getTypoExprState(TE); 6143 if (State.DiagHandler) { 6144 TypoCorrection TC = State.Consumer->getCurrentCorrection(); 6145 ExprResult Replacement = TransformCache[TE]; 6146 6147 // Extract the NamedDecl from the transformed TypoExpr and add it to the 6148 // TypoCorrection, replacing the existing decls. This ensures the right 6149 // NamedDecl is used in diagnostics e.g. in the case where overload 6150 // resolution was used to select one from several possible decls that 6151 // had been stored in the TypoCorrection. 6152 if (auto *ND = getDeclFromExpr( 6153 Replacement.isInvalid() ? nullptr : Replacement.get())) 6154 TC.setCorrectionDecl(ND); 6155 6156 State.DiagHandler(TC); 6157 } 6158 SemaRef.clearDelayedTypo(TE); 6159 } 6160 } 6161 6162 /// \brief If corrections for the first TypoExpr have been exhausted for a 6163 /// given combination of the other TypoExprs, retry those corrections against 6164 /// the next combination of substitutions for the other TypoExprs by advancing 6165 /// to the next potential correction of the second TypoExpr. For the second 6166 /// and subsequent TypoExprs, if its stream of corrections has been exhausted, 6167 /// the stream is reset and the next TypoExpr's stream is advanced by one (a 6168 /// TypoExpr's correction stream is advanced by removing the TypoExpr from the 6169 /// TransformCache). Returns true if there is still any untried combinations 6170 /// of corrections. 6171 bool CheckAndAdvanceTypoExprCorrectionStreams() { 6172 for (auto TE : TypoExprs) { 6173 auto &State = SemaRef.getTypoExprState(TE); 6174 TransformCache.erase(TE); 6175 if (!State.Consumer->finished()) 6176 return true; 6177 State.Consumer->resetCorrectionStream(); 6178 } 6179 return false; 6180 } 6181 6182 NamedDecl *getDeclFromExpr(Expr *E) { 6183 if (auto *OE = dyn_cast_or_null<OverloadExpr>(E)) 6184 E = OverloadResolution[OE]; 6185 6186 if (!E) 6187 return nullptr; 6188 if (auto *DRE = dyn_cast<DeclRefExpr>(E)) 6189 return DRE->getDecl(); 6190 if (auto *ME = dyn_cast<MemberExpr>(E)) 6191 return ME->getMemberDecl(); 6192 // FIXME: Add any other expr types that could be be seen by the delayed typo 6193 // correction TreeTransform for which the corresponding TypoCorrection could 6194 // contain multiple decls. 6195 return nullptr; 6196 } 6197 6198 ExprResult TryTransform(Expr *E) { 6199 Sema::SFINAETrap Trap(SemaRef); 6200 ExprResult Res = TransformExpr(E); 6201 if (Trap.hasErrorOccurred() || Res.isInvalid()) 6202 return ExprError(); 6203 6204 return ExprFilter(Res.get()); 6205 } 6206 6207public: 6208 TransformTypos(Sema &SemaRef, llvm::function_ref<ExprResult(Expr *)> Filter) 6209 : BaseTransform(SemaRef), ExprFilter(Filter) {} 6210 6211 ExprResult RebuildCallExpr(Expr *Callee, SourceLocation LParenLoc, 6212 MultiExprArg Args, 6213 SourceLocation RParenLoc, 6214 Expr *ExecConfig = nullptr) { 6215 auto Result = BaseTransform::RebuildCallExpr(Callee, LParenLoc, Args, 6216 RParenLoc, ExecConfig); 6217 if (auto *OE = dyn_cast<OverloadExpr>(Callee)) { 6218 if (Result.isUsable()) { 6219 Expr *ResultCall = Result.get(); 6220 if (auto *BE = dyn_cast<CXXBindTemporaryExpr>(ResultCall)) 6221 ResultCall = BE->getSubExpr(); 6222 if (auto *CE = dyn_cast<CallExpr>(ResultCall)) 6223 OverloadResolution[OE] = CE->getCallee(); 6224 } 6225 } 6226 return Result; 6227 } 6228 6229 ExprResult TransformLambdaExpr(LambdaExpr *E) { return Owned(E); } 6230 6231 ExprResult Transform(Expr *E) { 6232 ExprResult Res; 6233 while (true) { 6234 Res = TryTransform(E); 6235 6236 // Exit if either the transform was valid or if there were no TypoExprs 6237 // to transform that still have any untried correction candidates.. 6238 if (!Res.isInvalid() || 6239 !CheckAndAdvanceTypoExprCorrectionStreams()) 6240 break; 6241 } 6242 6243 // Ensure none of the TypoExprs have multiple typo correction candidates 6244 // with the same edit length that pass all the checks and filters. 6245 // TODO: Properly handle various permutations of possible corrections when 6246 // there is more than one potentially ambiguous typo correction. 6247 while (!AmbiguousTypoExprs.empty()) { 6248 auto TE = AmbiguousTypoExprs.back(); 6249 auto Cached = TransformCache[TE]; 6250 auto &State = SemaRef.getTypoExprState(TE); 6251 State.Consumer->saveCurrentPosition(); 6252 TransformCache.erase(TE); 6253 if (!TryTransform(E).isInvalid()) { 6254 State.Consumer->resetCorrectionStream(); 6255 TransformCache.erase(TE); 6256 Res = ExprError(); 6257 break; 6258 } 6259 AmbiguousTypoExprs.remove(TE); 6260 State.Consumer->restoreSavedPosition(); 6261 TransformCache[TE] = Cached; 6262 } 6263 6264 // Ensure that all of the TypoExprs within the current Expr have been found. 6265 if (!Res.isUsable()) 6266 FindTypoExprs(TypoExprs).TraverseStmt(E); 6267 6268 EmitAllDiagnostics(); 6269 6270 return Res; 6271 } 6272 6273 ExprResult TransformTypoExpr(TypoExpr *E) { 6274 // If the TypoExpr hasn't been seen before, record it. Otherwise, return the 6275 // cached transformation result if there is one and the TypoExpr isn't the 6276 // first one that was encountered. 6277 auto &CacheEntry = TransformCache[E]; 6278 if (!TypoExprs.insert(E) && !CacheEntry.isUnset()) { 6279 return CacheEntry; 6280 } 6281 6282 auto &State = SemaRef.getTypoExprState(E); 6283 assert(State.Consumer && "Cannot transform a cleared TypoExpr"); 6284 6285 // For the first TypoExpr and an uncached TypoExpr, find the next likely 6286 // typo correction and return it. 6287 while (TypoCorrection TC = State.Consumer->getNextCorrection()) { 6288 ExprResult NE = State.RecoveryHandler ? 6289 State.RecoveryHandler(SemaRef, E, TC) : 6290 attemptRecovery(SemaRef, *State.Consumer, TC); 6291 if (!NE.isInvalid()) { 6292 // Check whether there may be a second viable correction with the same 6293 // edit distance; if so, remember this TypoExpr may have an ambiguous 6294 // correction so it can be more thoroughly vetted later. 6295 TypoCorrection Next; 6296 if ((Next = State.Consumer->peekNextCorrection()) && 6297 Next.getEditDistance(false) == TC.getEditDistance(false)) { 6298 AmbiguousTypoExprs.insert(E); 6299 } else { 6300 AmbiguousTypoExprs.remove(E); 6301 } 6302 assert(!NE.isUnset() && 6303 "Typo was transformed into a valid-but-null ExprResult"); 6304 return CacheEntry = NE; 6305 } 6306 } 6307 return CacheEntry = ExprError(); 6308 } 6309}; 6310} 6311 6312ExprResult Sema::CorrectDelayedTyposInExpr( 6313 Expr *E, llvm::function_ref<ExprResult(Expr *)> Filter) { 6314 // If the current evaluation context indicates there are uncorrected typos 6315 // and the current expression isn't guaranteed to not have typos, try to 6316 // resolve any TypoExpr nodes that might be in the expression. 6317 if (E && !ExprEvalContexts.empty() && ExprEvalContexts.back().NumTypos && 6318 (E->isTypeDependent() || E->isValueDependent() || 6319 E->isInstantiationDependent())) { 6320 auto TyposInContext = ExprEvalContexts.back().NumTypos; 6321 assert(TyposInContext < ~0U && "Recursive call of CorrectDelayedTyposInExpr"); 6322 ExprEvalContexts.back().NumTypos = ~0U; 6323 auto TyposResolved = DelayedTypos.size(); 6324 auto Result = TransformTypos(*this, Filter).Transform(E); 6325 ExprEvalContexts.back().NumTypos = TyposInContext; 6326 TyposResolved -= DelayedTypos.size(); 6327 if (Result.isInvalid() || Result.get() != E) { 6328 ExprEvalContexts.back().NumTypos -= TyposResolved; 6329 return Result; 6330 } 6331 assert(TyposResolved == 0 && "Corrected typo but got same Expr back?"); 6332 } 6333 return E; 6334} 6335 6336ExprResult Sema::ActOnFinishFullExpr(Expr *FE, SourceLocation CC, 6337 bool DiscardedValue, 6338 bool IsConstexpr, 6339 bool IsLambdaInitCaptureInitializer) { 6340 ExprResult FullExpr = FE; 6341 6342 if (!FullExpr.get()) 6343 return ExprError(); 6344 6345 // If we are an init-expression in a lambdas init-capture, we should not 6346 // diagnose an unexpanded pack now (will be diagnosed once lambda-expr 6347 // containing full-expression is done). 6348 // template<class ... Ts> void test(Ts ... t) { 6349 // test([&a(t)]() { <-- (t) is an init-expr that shouldn't be diagnosed now. 6350 // return a; 6351 // }() ...); 6352 // } 6353 // FIXME: This is a hack. It would be better if we pushed the lambda scope 6354 // when we parse the lambda introducer, and teach capturing (but not 6355 // unexpanded pack detection) to walk over LambdaScopeInfos which don't have a 6356 // corresponding class yet (that is, have LambdaScopeInfo either represent a 6357 // lambda where we've entered the introducer but not the body, or represent a 6358 // lambda where we've entered the body, depending on where the 6359 // parser/instantiation has got to). 6360 if (!IsLambdaInitCaptureInitializer && 6361 DiagnoseUnexpandedParameterPack(FullExpr.get())) 6362 return ExprError(); 6363 6364 // Top-level expressions default to 'id' when we're in a debugger. 6365 if (DiscardedValue && getLangOpts().DebuggerCastResultToId && 6366 FullExpr.get()->getType() == Context.UnknownAnyTy) { 6367 FullExpr = forceUnknownAnyToType(FullExpr.get(), Context.getObjCIdType()); 6368 if (FullExpr.isInvalid()) 6369 return ExprError(); 6370 } 6371 6372 if (DiscardedValue) { 6373 FullExpr = CheckPlaceholderExpr(FullExpr.get()); 6374 if (FullExpr.isInvalid()) 6375 return ExprError(); 6376 6377 FullExpr = IgnoredValueConversions(FullExpr.get()); 6378 if (FullExpr.isInvalid()) 6379 return ExprError(); 6380 } 6381 6382 FullExpr = CorrectDelayedTyposInExpr(FullExpr.get()); 6383 if (FullExpr.isInvalid()) 6384 return ExprError(); 6385 6386 CheckCompletedExpr(FullExpr.get(), CC, IsConstexpr); 6387 6388 // At the end of this full expression (which could be a deeply nested 6389 // lambda), if there is a potential capture within the nested lambda, 6390 // have the outer capture-able lambda try and capture it. 6391 // Consider the following code: 6392 // void f(int, int); 6393 // void f(const int&, double); 6394 // void foo() { 6395 // const int x = 10, y = 20; 6396 // auto L = [=](auto a) { 6397 // auto M = [=](auto b) { 6398 // f(x, b); <-- requires x to be captured by L and M 6399 // f(y, a); <-- requires y to be captured by L, but not all Ms 6400 // }; 6401 // }; 6402 // } 6403 6404 // FIXME: Also consider what happens for something like this that involves 6405 // the gnu-extension statement-expressions or even lambda-init-captures: 6406 // void f() { 6407 // const int n = 0; 6408 // auto L = [&](auto a) { 6409 // +n + ({ 0; a; }); 6410 // }; 6411 // } 6412 // 6413 // Here, we see +n, and then the full-expression 0; ends, so we don't 6414 // capture n (and instead remove it from our list of potential captures), 6415 // and then the full-expression +n + ({ 0; }); ends, but it's too late 6416 // for us to see that we need to capture n after all. 6417 6418 LambdaScopeInfo *const CurrentLSI = getCurLambda(); 6419 // FIXME: PR 17877 showed that getCurLambda() can return a valid pointer 6420 // even if CurContext is not a lambda call operator. Refer to that Bug Report 6421 // for an example of the code that might cause this asynchrony. 6422 // By ensuring we are in the context of a lambda's call operator 6423 // we can fix the bug (we only need to check whether we need to capture 6424 // if we are within a lambda's body); but per the comments in that 6425 // PR, a proper fix would entail : 6426 // "Alternative suggestion: 6427 // - Add to Sema an integer holding the smallest (outermost) scope 6428 // index that we are *lexically* within, and save/restore/set to 6429 // FunctionScopes.size() in InstantiatingTemplate's 6430 // constructor/destructor. 6431 // - Teach the handful of places that iterate over FunctionScopes to 6432 // stop at the outermost enclosing lexical scope." 6433 const bool IsInLambdaDeclContext = isLambdaCallOperator(CurContext); 6434 if (IsInLambdaDeclContext && CurrentLSI && 6435 CurrentLSI->hasPotentialCaptures() && !FullExpr.isInvalid()) 6436 CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(FE, CurrentLSI, 6437 *this); 6438 return MaybeCreateExprWithCleanups(FullExpr); 6439} 6440 6441StmtResult Sema::ActOnFinishFullStmt(Stmt *FullStmt) { 6442 if (!FullStmt) return StmtError(); 6443 6444 return MaybeCreateStmtWithCleanups(FullStmt); 6445} 6446 6447Sema::IfExistsResult 6448Sema::CheckMicrosoftIfExistsSymbol(Scope *S, 6449 CXXScopeSpec &SS, 6450 const DeclarationNameInfo &TargetNameInfo) { 6451 DeclarationName TargetName = TargetNameInfo.getName(); 6452 if (!TargetName) 6453 return IER_DoesNotExist; 6454 6455 // If the name itself is dependent, then the result is dependent. 6456 if (TargetName.isDependentName()) 6457 return IER_Dependent; 6458 6459 // Do the redeclaration lookup in the current scope. 6460 LookupResult R(*this, TargetNameInfo, Sema::LookupAnyName, 6461 Sema::NotForRedeclaration); 6462 LookupParsedName(R, S, &SS); 6463 R.suppressDiagnostics(); 6464 6465 switch (R.getResultKind()) { 6466 case LookupResult::Found: 6467 case LookupResult::FoundOverloaded: 6468 case LookupResult::FoundUnresolvedValue: 6469 case LookupResult::Ambiguous: 6470 return IER_Exists; 6471 6472 case LookupResult::NotFound: 6473 return IER_DoesNotExist; 6474 6475 case LookupResult::NotFoundInCurrentInstantiation: 6476 return IER_Dependent; 6477 } 6478 6479 llvm_unreachable("Invalid LookupResult Kind!"); 6480} 6481 6482Sema::IfExistsResult 6483Sema::CheckMicrosoftIfExistsSymbol(Scope *S, SourceLocation KeywordLoc, 6484 bool IsIfExists, CXXScopeSpec &SS, 6485 UnqualifiedId &Name) { 6486 DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name); 6487 6488 // Check for unexpanded parameter packs. 6489 SmallVector<UnexpandedParameterPack, 4> Unexpanded; 6490 collectUnexpandedParameterPacks(SS, Unexpanded); 6491 collectUnexpandedParameterPacks(TargetNameInfo, Unexpanded); 6492 if (!Unexpanded.empty()) { 6493 DiagnoseUnexpandedParameterPacks(KeywordLoc, 6494 IsIfExists? UPPC_IfExists 6495 : UPPC_IfNotExists, 6496 Unexpanded); 6497 return IER_Error; 6498 } 6499 6500 return CheckMicrosoftIfExistsSymbol(S, SS, TargetNameInfo); 6501} 6502