SemaExprCXX.cpp revision 7a9f49296a6454b7a6f0edce89dc99d413a7e14e
1//===--- SemaExprCXX.cpp - Semantic Analysis for Expressions --------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements semantic analysis for C++ expressions. 11// 12//===----------------------------------------------------------------------===// 13 14#include "clang/Sema/SemaInternal.h" 15#include "clang/Sema/DeclSpec.h" 16#include "clang/Sema/Initialization.h" 17#include "clang/Sema/Lookup.h" 18#include "clang/Sema/ParsedTemplate.h" 19#include "clang/Sema/ScopeInfo.h" 20#include "clang/Sema/Scope.h" 21#include "clang/Sema/TemplateDeduction.h" 22#include "clang/AST/ASTContext.h" 23#include "clang/AST/CharUnits.h" 24#include "clang/AST/CXXInheritance.h" 25#include "clang/AST/DeclObjC.h" 26#include "clang/AST/ExprCXX.h" 27#include "clang/AST/ExprObjC.h" 28#include "clang/AST/TypeLoc.h" 29#include "clang/Basic/PartialDiagnostic.h" 30#include "clang/Basic/TargetInfo.h" 31#include "clang/Lex/Preprocessor.h" 32#include "TypeLocBuilder.h" 33#include "llvm/ADT/APInt.h" 34#include "llvm/ADT/STLExtras.h" 35#include "llvm/Support/ErrorHandling.h" 36using namespace clang; 37using namespace sema; 38 39ParsedType Sema::getDestructorName(SourceLocation TildeLoc, 40 IdentifierInfo &II, 41 SourceLocation NameLoc, 42 Scope *S, CXXScopeSpec &SS, 43 ParsedType ObjectTypePtr, 44 bool EnteringContext) { 45 // Determine where to perform name lookup. 46 47 // FIXME: This area of the standard is very messy, and the current 48 // wording is rather unclear about which scopes we search for the 49 // destructor name; see core issues 399 and 555. Issue 399 in 50 // particular shows where the current description of destructor name 51 // lookup is completely out of line with existing practice, e.g., 52 // this appears to be ill-formed: 53 // 54 // namespace N { 55 // template <typename T> struct S { 56 // ~S(); 57 // }; 58 // } 59 // 60 // void f(N::S<int>* s) { 61 // s->N::S<int>::~S(); 62 // } 63 // 64 // See also PR6358 and PR6359. 65 // For this reason, we're currently only doing the C++03 version of this 66 // code; the C++0x version has to wait until we get a proper spec. 67 QualType SearchType; 68 DeclContext *LookupCtx = 0; 69 bool isDependent = false; 70 bool LookInScope = false; 71 72 // If we have an object type, it's because we are in a 73 // pseudo-destructor-expression or a member access expression, and 74 // we know what type we're looking for. 75 if (ObjectTypePtr) 76 SearchType = GetTypeFromParser(ObjectTypePtr); 77 78 if (SS.isSet()) { 79 NestedNameSpecifier *NNS = (NestedNameSpecifier *)SS.getScopeRep(); 80 81 bool AlreadySearched = false; 82 bool LookAtPrefix = true; 83 // C++ [basic.lookup.qual]p6: 84 // If a pseudo-destructor-name (5.2.4) contains a nested-name-specifier, 85 // the type-names are looked up as types in the scope designated by the 86 // nested-name-specifier. In a qualified-id of the form: 87 // 88 // ::[opt] nested-name-specifier ~ class-name 89 // 90 // where the nested-name-specifier designates a namespace scope, and in 91 // a qualified-id of the form: 92 // 93 // ::opt nested-name-specifier class-name :: ~ class-name 94 // 95 // the class-names are looked up as types in the scope designated by 96 // the nested-name-specifier. 97 // 98 // Here, we check the first case (completely) and determine whether the 99 // code below is permitted to look at the prefix of the 100 // nested-name-specifier. 101 DeclContext *DC = computeDeclContext(SS, EnteringContext); 102 if (DC && DC->isFileContext()) { 103 AlreadySearched = true; 104 LookupCtx = DC; 105 isDependent = false; 106 } else if (DC && isa<CXXRecordDecl>(DC)) 107 LookAtPrefix = false; 108 109 // The second case from the C++03 rules quoted further above. 110 NestedNameSpecifier *Prefix = 0; 111 if (AlreadySearched) { 112 // Nothing left to do. 113 } else if (LookAtPrefix && (Prefix = NNS->getPrefix())) { 114 CXXScopeSpec PrefixSS; 115 PrefixSS.Adopt(NestedNameSpecifierLoc(Prefix, SS.location_data())); 116 LookupCtx = computeDeclContext(PrefixSS, EnteringContext); 117 isDependent = isDependentScopeSpecifier(PrefixSS); 118 } else if (ObjectTypePtr) { 119 LookupCtx = computeDeclContext(SearchType); 120 isDependent = SearchType->isDependentType(); 121 } else { 122 LookupCtx = computeDeclContext(SS, EnteringContext); 123 isDependent = LookupCtx && LookupCtx->isDependentContext(); 124 } 125 126 LookInScope = false; 127 } else if (ObjectTypePtr) { 128 // C++ [basic.lookup.classref]p3: 129 // If the unqualified-id is ~type-name, the type-name is looked up 130 // in the context of the entire postfix-expression. If the type T 131 // of the object expression is of a class type C, the type-name is 132 // also looked up in the scope of class C. At least one of the 133 // lookups shall find a name that refers to (possibly 134 // cv-qualified) T. 135 LookupCtx = computeDeclContext(SearchType); 136 isDependent = SearchType->isDependentType(); 137 assert((isDependent || !SearchType->isIncompleteType()) && 138 "Caller should have completed object type"); 139 140 LookInScope = true; 141 } else { 142 // Perform lookup into the current scope (only). 143 LookInScope = true; 144 } 145 146 TypeDecl *NonMatchingTypeDecl = 0; 147 LookupResult Found(*this, &II, NameLoc, LookupOrdinaryName); 148 for (unsigned Step = 0; Step != 2; ++Step) { 149 // Look for the name first in the computed lookup context (if we 150 // have one) and, if that fails to find a match, in the scope (if 151 // we're allowed to look there). 152 Found.clear(); 153 if (Step == 0 && LookupCtx) 154 LookupQualifiedName(Found, LookupCtx); 155 else if (Step == 1 && LookInScope && S) 156 LookupName(Found, S); 157 else 158 continue; 159 160 // FIXME: Should we be suppressing ambiguities here? 161 if (Found.isAmbiguous()) 162 return ParsedType(); 163 164 if (TypeDecl *Type = Found.getAsSingle<TypeDecl>()) { 165 QualType T = Context.getTypeDeclType(Type); 166 167 if (SearchType.isNull() || SearchType->isDependentType() || 168 Context.hasSameUnqualifiedType(T, SearchType)) { 169 // We found our type! 170 171 return ParsedType::make(T); 172 } 173 174 if (!SearchType.isNull()) 175 NonMatchingTypeDecl = Type; 176 } 177 178 // If the name that we found is a class template name, and it is 179 // the same name as the template name in the last part of the 180 // nested-name-specifier (if present) or the object type, then 181 // this is the destructor for that class. 182 // FIXME: This is a workaround until we get real drafting for core 183 // issue 399, for which there isn't even an obvious direction. 184 if (ClassTemplateDecl *Template = Found.getAsSingle<ClassTemplateDecl>()) { 185 QualType MemberOfType; 186 if (SS.isSet()) { 187 if (DeclContext *Ctx = computeDeclContext(SS, EnteringContext)) { 188 // Figure out the type of the context, if it has one. 189 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) 190 MemberOfType = Context.getTypeDeclType(Record); 191 } 192 } 193 if (MemberOfType.isNull()) 194 MemberOfType = SearchType; 195 196 if (MemberOfType.isNull()) 197 continue; 198 199 // We're referring into a class template specialization. If the 200 // class template we found is the same as the template being 201 // specialized, we found what we are looking for. 202 if (const RecordType *Record = MemberOfType->getAs<RecordType>()) { 203 if (ClassTemplateSpecializationDecl *Spec 204 = dyn_cast<ClassTemplateSpecializationDecl>(Record->getDecl())) { 205 if (Spec->getSpecializedTemplate()->getCanonicalDecl() == 206 Template->getCanonicalDecl()) 207 return ParsedType::make(MemberOfType); 208 } 209 210 continue; 211 } 212 213 // We're referring to an unresolved class template 214 // specialization. Determine whether we class template we found 215 // is the same as the template being specialized or, if we don't 216 // know which template is being specialized, that it at least 217 // has the same name. 218 if (const TemplateSpecializationType *SpecType 219 = MemberOfType->getAs<TemplateSpecializationType>()) { 220 TemplateName SpecName = SpecType->getTemplateName(); 221 222 // The class template we found is the same template being 223 // specialized. 224 if (TemplateDecl *SpecTemplate = SpecName.getAsTemplateDecl()) { 225 if (SpecTemplate->getCanonicalDecl() == Template->getCanonicalDecl()) 226 return ParsedType::make(MemberOfType); 227 228 continue; 229 } 230 231 // The class template we found has the same name as the 232 // (dependent) template name being specialized. 233 if (DependentTemplateName *DepTemplate 234 = SpecName.getAsDependentTemplateName()) { 235 if (DepTemplate->isIdentifier() && 236 DepTemplate->getIdentifier() == Template->getIdentifier()) 237 return ParsedType::make(MemberOfType); 238 239 continue; 240 } 241 } 242 } 243 } 244 245 if (isDependent) { 246 // We didn't find our type, but that's okay: it's dependent 247 // anyway. 248 249 // FIXME: What if we have no nested-name-specifier? 250 QualType T = CheckTypenameType(ETK_None, SourceLocation(), 251 SS.getWithLocInContext(Context), 252 II, NameLoc); 253 return ParsedType::make(T); 254 } 255 256 if (NonMatchingTypeDecl) { 257 QualType T = Context.getTypeDeclType(NonMatchingTypeDecl); 258 Diag(NameLoc, diag::err_destructor_expr_type_mismatch) 259 << T << SearchType; 260 Diag(NonMatchingTypeDecl->getLocation(), diag::note_destructor_type_here) 261 << T; 262 } else if (ObjectTypePtr) 263 Diag(NameLoc, diag::err_ident_in_dtor_not_a_type) 264 << &II; 265 else 266 Diag(NameLoc, diag::err_destructor_class_name); 267 268 return ParsedType(); 269} 270 271ParsedType Sema::getDestructorType(const DeclSpec& DS, ParsedType ObjectType) { 272 if (DS.getTypeSpecType() == DeclSpec::TST_error || !ObjectType) 273 return ParsedType(); 274 assert(DS.getTypeSpecType() == DeclSpec::TST_decltype 275 && "only get destructor types from declspecs"); 276 QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc()); 277 QualType SearchType = GetTypeFromParser(ObjectType); 278 if (SearchType->isDependentType() || Context.hasSameUnqualifiedType(SearchType, T)) { 279 return ParsedType::make(T); 280 } 281 282 Diag(DS.getTypeSpecTypeLoc(), diag::err_destructor_expr_type_mismatch) 283 << T << SearchType; 284 return ParsedType(); 285} 286 287/// \brief Build a C++ typeid expression with a type operand. 288ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType, 289 SourceLocation TypeidLoc, 290 TypeSourceInfo *Operand, 291 SourceLocation RParenLoc) { 292 // C++ [expr.typeid]p4: 293 // The top-level cv-qualifiers of the lvalue expression or the type-id 294 // that is the operand of typeid are always ignored. 295 // If the type of the type-id is a class type or a reference to a class 296 // type, the class shall be completely-defined. 297 Qualifiers Quals; 298 QualType T 299 = Context.getUnqualifiedArrayType(Operand->getType().getNonReferenceType(), 300 Quals); 301 if (T->getAs<RecordType>() && 302 RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid)) 303 return ExprError(); 304 305 return Owned(new (Context) CXXTypeidExpr(TypeInfoType.withConst(), 306 Operand, 307 SourceRange(TypeidLoc, RParenLoc))); 308} 309 310/// \brief Build a C++ typeid expression with an expression operand. 311ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType, 312 SourceLocation TypeidLoc, 313 Expr *E, 314 SourceLocation RParenLoc) { 315 if (E && !E->isTypeDependent()) { 316 if (E->getType()->isPlaceholderType()) { 317 ExprResult result = CheckPlaceholderExpr(E); 318 if (result.isInvalid()) return ExprError(); 319 E = result.take(); 320 } 321 322 QualType T = E->getType(); 323 if (const RecordType *RecordT = T->getAs<RecordType>()) { 324 CXXRecordDecl *RecordD = cast<CXXRecordDecl>(RecordT->getDecl()); 325 // C++ [expr.typeid]p3: 326 // [...] If the type of the expression is a class type, the class 327 // shall be completely-defined. 328 if (RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid)) 329 return ExprError(); 330 331 // C++ [expr.typeid]p3: 332 // When typeid is applied to an expression other than an glvalue of a 333 // polymorphic class type [...] [the] expression is an unevaluated 334 // operand. [...] 335 if (RecordD->isPolymorphic() && E->Classify(Context).isGLValue()) { 336 // The subexpression is potentially evaluated; switch the context 337 // and recheck the subexpression. 338 ExprResult Result = TranformToPotentiallyEvaluated(E); 339 if (Result.isInvalid()) return ExprError(); 340 E = Result.take(); 341 342 // We require a vtable to query the type at run time. 343 MarkVTableUsed(TypeidLoc, RecordD); 344 } 345 } 346 347 // C++ [expr.typeid]p4: 348 // [...] If the type of the type-id is a reference to a possibly 349 // cv-qualified type, the result of the typeid expression refers to a 350 // std::type_info object representing the cv-unqualified referenced 351 // type. 352 Qualifiers Quals; 353 QualType UnqualT = Context.getUnqualifiedArrayType(T, Quals); 354 if (!Context.hasSameType(T, UnqualT)) { 355 T = UnqualT; 356 E = ImpCastExprToType(E, UnqualT, CK_NoOp, E->getValueKind()).take(); 357 } 358 } 359 360 return Owned(new (Context) CXXTypeidExpr(TypeInfoType.withConst(), 361 E, 362 SourceRange(TypeidLoc, RParenLoc))); 363} 364 365/// ActOnCXXTypeidOfType - Parse typeid( type-id ) or typeid (expression); 366ExprResult 367Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc, 368 bool isType, void *TyOrExpr, SourceLocation RParenLoc) { 369 // Find the std::type_info type. 370 if (!getStdNamespace()) 371 return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid)); 372 373 if (!CXXTypeInfoDecl) { 374 IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info"); 375 LookupResult R(*this, TypeInfoII, SourceLocation(), LookupTagName); 376 LookupQualifiedName(R, getStdNamespace()); 377 CXXTypeInfoDecl = R.getAsSingle<RecordDecl>(); 378 if (!CXXTypeInfoDecl) 379 return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid)); 380 } 381 382 QualType TypeInfoType = Context.getTypeDeclType(CXXTypeInfoDecl); 383 384 if (isType) { 385 // The operand is a type; handle it as such. 386 TypeSourceInfo *TInfo = 0; 387 QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr), 388 &TInfo); 389 if (T.isNull()) 390 return ExprError(); 391 392 if (!TInfo) 393 TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc); 394 395 return BuildCXXTypeId(TypeInfoType, OpLoc, TInfo, RParenLoc); 396 } 397 398 // The operand is an expression. 399 return BuildCXXTypeId(TypeInfoType, OpLoc, (Expr*)TyOrExpr, RParenLoc); 400} 401 402/// Retrieve the UuidAttr associated with QT. 403static UuidAttr *GetUuidAttrOfType(QualType QT) { 404 // Optionally remove one level of pointer, reference or array indirection. 405 const Type *Ty = QT.getTypePtr();; 406 if (QT->isPointerType() || QT->isReferenceType()) 407 Ty = QT->getPointeeType().getTypePtr(); 408 else if (QT->isArrayType()) 409 Ty = cast<ArrayType>(QT)->getElementType().getTypePtr(); 410 411 // Loop all record redeclaration looking for an uuid attribute. 412 CXXRecordDecl *RD = Ty->getAsCXXRecordDecl(); 413 for (CXXRecordDecl::redecl_iterator I = RD->redecls_begin(), 414 E = RD->redecls_end(); I != E; ++I) { 415 if (UuidAttr *Uuid = I->getAttr<UuidAttr>()) 416 return Uuid; 417 } 418 419 return 0; 420} 421 422/// \brief Build a Microsoft __uuidof expression with a type operand. 423ExprResult Sema::BuildCXXUuidof(QualType TypeInfoType, 424 SourceLocation TypeidLoc, 425 TypeSourceInfo *Operand, 426 SourceLocation RParenLoc) { 427 if (!Operand->getType()->isDependentType()) { 428 if (!GetUuidAttrOfType(Operand->getType())) 429 return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid)); 430 } 431 432 // FIXME: add __uuidof semantic analysis for type operand. 433 return Owned(new (Context) CXXUuidofExpr(TypeInfoType.withConst(), 434 Operand, 435 SourceRange(TypeidLoc, RParenLoc))); 436} 437 438/// \brief Build a Microsoft __uuidof expression with an expression operand. 439ExprResult Sema::BuildCXXUuidof(QualType TypeInfoType, 440 SourceLocation TypeidLoc, 441 Expr *E, 442 SourceLocation RParenLoc) { 443 if (!E->getType()->isDependentType()) { 444 if (!GetUuidAttrOfType(E->getType()) && 445 !E->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 446 return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid)); 447 } 448 // FIXME: add __uuidof semantic analysis for type operand. 449 return Owned(new (Context) CXXUuidofExpr(TypeInfoType.withConst(), 450 E, 451 SourceRange(TypeidLoc, RParenLoc))); 452} 453 454/// ActOnCXXUuidof - Parse __uuidof( type-id ) or __uuidof (expression); 455ExprResult 456Sema::ActOnCXXUuidof(SourceLocation OpLoc, SourceLocation LParenLoc, 457 bool isType, void *TyOrExpr, SourceLocation RParenLoc) { 458 // If MSVCGuidDecl has not been cached, do the lookup. 459 if (!MSVCGuidDecl) { 460 IdentifierInfo *GuidII = &PP.getIdentifierTable().get("_GUID"); 461 LookupResult R(*this, GuidII, SourceLocation(), LookupTagName); 462 LookupQualifiedName(R, Context.getTranslationUnitDecl()); 463 MSVCGuidDecl = R.getAsSingle<RecordDecl>(); 464 if (!MSVCGuidDecl) 465 return ExprError(Diag(OpLoc, diag::err_need_header_before_ms_uuidof)); 466 } 467 468 QualType GuidType = Context.getTypeDeclType(MSVCGuidDecl); 469 470 if (isType) { 471 // The operand is a type; handle it as such. 472 TypeSourceInfo *TInfo = 0; 473 QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr), 474 &TInfo); 475 if (T.isNull()) 476 return ExprError(); 477 478 if (!TInfo) 479 TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc); 480 481 return BuildCXXUuidof(GuidType, OpLoc, TInfo, RParenLoc); 482 } 483 484 // The operand is an expression. 485 return BuildCXXUuidof(GuidType, OpLoc, (Expr*)TyOrExpr, RParenLoc); 486} 487 488/// ActOnCXXBoolLiteral - Parse {true,false} literals. 489ExprResult 490Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) { 491 assert((Kind == tok::kw_true || Kind == tok::kw_false) && 492 "Unknown C++ Boolean value!"); 493 return Owned(new (Context) CXXBoolLiteralExpr(Kind == tok::kw_true, 494 Context.BoolTy, OpLoc)); 495} 496 497/// ActOnCXXNullPtrLiteral - Parse 'nullptr'. 498ExprResult 499Sema::ActOnCXXNullPtrLiteral(SourceLocation Loc) { 500 return Owned(new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc)); 501} 502 503/// ActOnCXXThrow - Parse throw expressions. 504ExprResult 505Sema::ActOnCXXThrow(Scope *S, SourceLocation OpLoc, Expr *Ex) { 506 bool IsThrownVarInScope = false; 507 if (Ex) { 508 // C++0x [class.copymove]p31: 509 // When certain criteria are met, an implementation is allowed to omit the 510 // copy/move construction of a class object [...] 511 // 512 // - in a throw-expression, when the operand is the name of a 513 // non-volatile automatic object (other than a function or catch- 514 // clause parameter) whose scope does not extend beyond the end of the 515 // innermost enclosing try-block (if there is one), the copy/move 516 // operation from the operand to the exception object (15.1) can be 517 // omitted by constructing the automatic object directly into the 518 // exception object 519 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Ex->IgnoreParens())) 520 if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) { 521 if (Var->hasLocalStorage() && !Var->getType().isVolatileQualified()) { 522 for( ; S; S = S->getParent()) { 523 if (S->isDeclScope(Var)) { 524 IsThrownVarInScope = true; 525 break; 526 } 527 528 if (S->getFlags() & 529 (Scope::FnScope | Scope::ClassScope | Scope::BlockScope | 530 Scope::FunctionPrototypeScope | Scope::ObjCMethodScope | 531 Scope::TryScope)) 532 break; 533 } 534 } 535 } 536 } 537 538 return BuildCXXThrow(OpLoc, Ex, IsThrownVarInScope); 539} 540 541ExprResult Sema::BuildCXXThrow(SourceLocation OpLoc, Expr *Ex, 542 bool IsThrownVarInScope) { 543 // Don't report an error if 'throw' is used in system headers. 544 if (!getLangOptions().CXXExceptions && 545 !getSourceManager().isInSystemHeader(OpLoc)) 546 Diag(OpLoc, diag::err_exceptions_disabled) << "throw"; 547 548 if (Ex && !Ex->isTypeDependent()) { 549 ExprResult ExRes = CheckCXXThrowOperand(OpLoc, Ex, IsThrownVarInScope); 550 if (ExRes.isInvalid()) 551 return ExprError(); 552 Ex = ExRes.take(); 553 } 554 555 return Owned(new (Context) CXXThrowExpr(Ex, Context.VoidTy, OpLoc, 556 IsThrownVarInScope)); 557} 558 559/// CheckCXXThrowOperand - Validate the operand of a throw. 560ExprResult Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc, Expr *E, 561 bool IsThrownVarInScope) { 562 // C++ [except.throw]p3: 563 // A throw-expression initializes a temporary object, called the exception 564 // object, the type of which is determined by removing any top-level 565 // cv-qualifiers from the static type of the operand of throw and adjusting 566 // the type from "array of T" or "function returning T" to "pointer to T" 567 // or "pointer to function returning T", [...] 568 if (E->getType().hasQualifiers()) 569 E = ImpCastExprToType(E, E->getType().getUnqualifiedType(), CK_NoOp, 570 E->getValueKind()).take(); 571 572 ExprResult Res = DefaultFunctionArrayConversion(E); 573 if (Res.isInvalid()) 574 return ExprError(); 575 E = Res.take(); 576 577 // If the type of the exception would be an incomplete type or a pointer 578 // to an incomplete type other than (cv) void the program is ill-formed. 579 QualType Ty = E->getType(); 580 bool isPointer = false; 581 if (const PointerType* Ptr = Ty->getAs<PointerType>()) { 582 Ty = Ptr->getPointeeType(); 583 isPointer = true; 584 } 585 if (!isPointer || !Ty->isVoidType()) { 586 if (RequireCompleteType(ThrowLoc, Ty, 587 PDiag(isPointer ? diag::err_throw_incomplete_ptr 588 : diag::err_throw_incomplete) 589 << E->getSourceRange())) 590 return ExprError(); 591 592 if (RequireNonAbstractType(ThrowLoc, E->getType(), 593 PDiag(diag::err_throw_abstract_type) 594 << E->getSourceRange())) 595 return ExprError(); 596 } 597 598 // Initialize the exception result. This implicitly weeds out 599 // abstract types or types with inaccessible copy constructors. 600 601 // C++0x [class.copymove]p31: 602 // When certain criteria are met, an implementation is allowed to omit the 603 // copy/move construction of a class object [...] 604 // 605 // - in a throw-expression, when the operand is the name of a 606 // non-volatile automatic object (other than a function or catch-clause 607 // parameter) whose scope does not extend beyond the end of the 608 // innermost enclosing try-block (if there is one), the copy/move 609 // operation from the operand to the exception object (15.1) can be 610 // omitted by constructing the automatic object directly into the 611 // exception object 612 const VarDecl *NRVOVariable = 0; 613 if (IsThrownVarInScope) 614 NRVOVariable = getCopyElisionCandidate(QualType(), E, false); 615 616 InitializedEntity Entity = 617 InitializedEntity::InitializeException(ThrowLoc, E->getType(), 618 /*NRVO=*/NRVOVariable != 0); 619 Res = PerformMoveOrCopyInitialization(Entity, NRVOVariable, 620 QualType(), E, 621 IsThrownVarInScope); 622 if (Res.isInvalid()) 623 return ExprError(); 624 E = Res.take(); 625 626 // If the exception has class type, we need additional handling. 627 const RecordType *RecordTy = Ty->getAs<RecordType>(); 628 if (!RecordTy) 629 return Owned(E); 630 CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl()); 631 632 // If we are throwing a polymorphic class type or pointer thereof, 633 // exception handling will make use of the vtable. 634 MarkVTableUsed(ThrowLoc, RD); 635 636 // If a pointer is thrown, the referenced object will not be destroyed. 637 if (isPointer) 638 return Owned(E); 639 640 // If the class has a destructor, we must be able to call it. 641 if (RD->hasIrrelevantDestructor()) 642 return Owned(E); 643 644 CXXDestructorDecl *Destructor 645 = const_cast<CXXDestructorDecl*>(LookupDestructor(RD)); 646 if (!Destructor) 647 return Owned(E); 648 649 MarkFunctionReferenced(E->getExprLoc(), Destructor); 650 CheckDestructorAccess(E->getExprLoc(), Destructor, 651 PDiag(diag::err_access_dtor_exception) << Ty); 652 DiagnoseUseOfDecl(Destructor, E->getExprLoc()); 653 return Owned(E); 654} 655 656QualType Sema::getCurrentThisType() { 657 DeclContext *DC = getFunctionLevelDeclContext(); 658 QualType ThisTy; 659 if (CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(DC)) { 660 if (method && method->isInstance()) 661 ThisTy = method->getThisType(Context); 662 } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) { 663 // C++0x [expr.prim]p4: 664 // Otherwise, if a member-declarator declares a non-static data member 665 // of a class X, the expression this is a prvalue of type "pointer to X" 666 // within the optional brace-or-equal-initializer. 667 Scope *S = getScopeForContext(DC); 668 if (!S || S->getFlags() & Scope::ThisScope) 669 ThisTy = Context.getPointerType(Context.getRecordType(RD)); 670 } 671 672 return ThisTy; 673} 674 675void Sema::CheckCXXThisCapture(SourceLocation Loc, bool Explicit) { 676 // We don't need to capture this in an unevaluated context. 677 if (ExprEvalContexts.back().Context == Unevaluated && !Explicit) 678 return; 679 680 // Otherwise, check that we can capture 'this'. 681 unsigned NumClosures = 0; 682 for (unsigned idx = FunctionScopes.size() - 1; idx != 0; idx--) { 683 if (CapturingScopeInfo *CSI = 684 dyn_cast<CapturingScopeInfo>(FunctionScopes[idx])) { 685 if (CSI->CXXThisCaptureIndex != 0) { 686 // 'this' is already being captured; there isn't anything more to do. 687 break; 688 } 689 690 if (CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByref || 691 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval || 692 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_Block || 693 Explicit) { 694 // This closure can capture 'this'; continue looking upwards. 695 NumClosures++; 696 Explicit = false; 697 continue; 698 } 699 // This context can't implicitly capture 'this'; fail out. 700 Diag(Loc, diag::err_this_capture) << Explicit; 701 return; 702 } 703 break; 704 } 705 706 // Mark that we're implicitly capturing 'this' in all the scopes we skipped. 707 // FIXME: We need to delay this marking in PotentiallyPotentiallyEvaluated 708 // contexts. 709 for (unsigned idx = FunctionScopes.size() - 1; 710 NumClosures; --idx, --NumClosures) { 711 CapturingScopeInfo *CSI = cast<CapturingScopeInfo>(FunctionScopes[idx]); 712 Expr *ThisExpr = 0; 713 QualType ThisTy = getCurrentThisType(); 714 if (LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI)) { 715 // For lambda expressions, build a field and an initializing expression. 716 CXXRecordDecl *Lambda = LSI->Lambda; 717 FieldDecl *Field 718 = FieldDecl::Create(Context, Lambda, Loc, Loc, 0, ThisTy, 719 Context.getTrivialTypeSourceInfo(ThisTy, Loc), 720 0, false, false); 721 Field->setImplicit(true); 722 Field->setAccess(AS_private); 723 Lambda->addDecl(Field); 724 ThisExpr = new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit=*/true); 725 } 726 bool isNested = NumClosures > 1; 727 CSI->addThisCapture(isNested, Loc, ThisTy, ThisExpr); 728 } 729} 730 731ExprResult Sema::ActOnCXXThis(SourceLocation Loc) { 732 /// C++ 9.3.2: In the body of a non-static member function, the keyword this 733 /// is a non-lvalue expression whose value is the address of the object for 734 /// which the function is called. 735 736 QualType ThisTy = getCurrentThisType(); 737 if (ThisTy.isNull()) return Diag(Loc, diag::err_invalid_this_use); 738 739 CheckCXXThisCapture(Loc); 740 return Owned(new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit=*/false)); 741} 742 743ExprResult 744Sema::ActOnCXXTypeConstructExpr(ParsedType TypeRep, 745 SourceLocation LParenLoc, 746 MultiExprArg exprs, 747 SourceLocation RParenLoc) { 748 if (!TypeRep) 749 return ExprError(); 750 751 TypeSourceInfo *TInfo; 752 QualType Ty = GetTypeFromParser(TypeRep, &TInfo); 753 if (!TInfo) 754 TInfo = Context.getTrivialTypeSourceInfo(Ty, SourceLocation()); 755 756 return BuildCXXTypeConstructExpr(TInfo, LParenLoc, exprs, RParenLoc); 757} 758 759/// ActOnCXXTypeConstructExpr - Parse construction of a specified type. 760/// Can be interpreted either as function-style casting ("int(x)") 761/// or class type construction ("ClassType(x,y,z)") 762/// or creation of a value-initialized type ("int()"). 763ExprResult 764Sema::BuildCXXTypeConstructExpr(TypeSourceInfo *TInfo, 765 SourceLocation LParenLoc, 766 MultiExprArg exprs, 767 SourceLocation RParenLoc) { 768 QualType Ty = TInfo->getType(); 769 unsigned NumExprs = exprs.size(); 770 Expr **Exprs = (Expr**)exprs.get(); 771 SourceLocation TyBeginLoc = TInfo->getTypeLoc().getBeginLoc(); 772 773 if (Ty->isDependentType() || 774 CallExpr::hasAnyTypeDependentArguments(Exprs, NumExprs)) { 775 exprs.release(); 776 777 return Owned(CXXUnresolvedConstructExpr::Create(Context, TInfo, 778 LParenLoc, 779 Exprs, NumExprs, 780 RParenLoc)); 781 } 782 783 bool ListInitialization = LParenLoc.isInvalid(); 784 assert((!ListInitialization || (NumExprs == 1 && isa<InitListExpr>(Exprs[0]))) 785 && "List initialization must have initializer list as expression."); 786 SourceRange FullRange = SourceRange(TyBeginLoc, 787 ListInitialization ? Exprs[0]->getSourceRange().getEnd() : RParenLoc); 788 789 if (Ty->isArrayType()) 790 return ExprError(Diag(TyBeginLoc, 791 diag::err_value_init_for_array_type) << FullRange); 792 if (!Ty->isVoidType() && 793 RequireCompleteType(TyBeginLoc, Ty, 794 PDiag(diag::err_invalid_incomplete_type_use) 795 << FullRange)) 796 return ExprError(); 797 798 if (RequireNonAbstractType(TyBeginLoc, Ty, 799 diag::err_allocation_of_abstract_type)) 800 return ExprError(); 801 802 803 // C++ [expr.type.conv]p1: 804 // If the expression list is a single expression, the type conversion 805 // expression is equivalent (in definedness, and if defined in meaning) to the 806 // corresponding cast expression. 807 if (NumExprs == 1 && !ListInitialization) { 808 Expr *Arg = Exprs[0]; 809 exprs.release(); 810 return BuildCXXFunctionalCastExpr(TInfo, LParenLoc, Arg, RParenLoc); 811 } 812 813 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TInfo); 814 InitializationKind Kind 815 = NumExprs ? ListInitialization 816 ? InitializationKind::CreateDirectList(TyBeginLoc) 817 : InitializationKind::CreateDirect(TyBeginLoc, 818 LParenLoc, RParenLoc) 819 : InitializationKind::CreateValue(TyBeginLoc, 820 LParenLoc, RParenLoc); 821 InitializationSequence InitSeq(*this, Entity, Kind, Exprs, NumExprs); 822 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, move(exprs)); 823 824 if (!Result.isInvalid() && ListInitialization && 825 isa<InitListExpr>(Result.get())) { 826 // If the list-initialization doesn't involve a constructor call, we'll get 827 // the initializer-list (with corrected type) back, but that's not what we 828 // want, since it will be treated as an initializer list in further 829 // processing. Explicitly insert a cast here. 830 InitListExpr *List = cast<InitListExpr>(Result.take()); 831 Result = Owned(CXXFunctionalCastExpr::Create(Context, List->getType(), 832 Expr::getValueKindForType(TInfo->getType()), 833 TInfo, TyBeginLoc, CK_NoOp, 834 List, /*Path=*/0, RParenLoc)); 835 } 836 837 // FIXME: Improve AST representation? 838 return move(Result); 839} 840 841/// doesUsualArrayDeleteWantSize - Answers whether the usual 842/// operator delete[] for the given type has a size_t parameter. 843static bool doesUsualArrayDeleteWantSize(Sema &S, SourceLocation loc, 844 QualType allocType) { 845 const RecordType *record = 846 allocType->getBaseElementTypeUnsafe()->getAs<RecordType>(); 847 if (!record) return false; 848 849 // Try to find an operator delete[] in class scope. 850 851 DeclarationName deleteName = 852 S.Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete); 853 LookupResult ops(S, deleteName, loc, Sema::LookupOrdinaryName); 854 S.LookupQualifiedName(ops, record->getDecl()); 855 856 // We're just doing this for information. 857 ops.suppressDiagnostics(); 858 859 // Very likely: there's no operator delete[]. 860 if (ops.empty()) return false; 861 862 // If it's ambiguous, it should be illegal to call operator delete[] 863 // on this thing, so it doesn't matter if we allocate extra space or not. 864 if (ops.isAmbiguous()) return false; 865 866 LookupResult::Filter filter = ops.makeFilter(); 867 while (filter.hasNext()) { 868 NamedDecl *del = filter.next()->getUnderlyingDecl(); 869 870 // C++0x [basic.stc.dynamic.deallocation]p2: 871 // A template instance is never a usual deallocation function, 872 // regardless of its signature. 873 if (isa<FunctionTemplateDecl>(del)) { 874 filter.erase(); 875 continue; 876 } 877 878 // C++0x [basic.stc.dynamic.deallocation]p2: 879 // If class T does not declare [an operator delete[] with one 880 // parameter] but does declare a member deallocation function 881 // named operator delete[] with exactly two parameters, the 882 // second of which has type std::size_t, then this function 883 // is a usual deallocation function. 884 if (!cast<CXXMethodDecl>(del)->isUsualDeallocationFunction()) { 885 filter.erase(); 886 continue; 887 } 888 } 889 filter.done(); 890 891 if (!ops.isSingleResult()) return false; 892 893 const FunctionDecl *del = cast<FunctionDecl>(ops.getFoundDecl()); 894 return (del->getNumParams() == 2); 895} 896 897/// \brief Parsed a C++ 'new' expression (C++ 5.3.4). 898 899/// E.g.: 900/// @code new (memory) int[size][4] @endcode 901/// or 902/// @code ::new Foo(23, "hello") @endcode 903/// 904/// \param StartLoc The first location of the expression. 905/// \param UseGlobal True if 'new' was prefixed with '::'. 906/// \param PlacementLParen Opening paren of the placement arguments. 907/// \param PlacementArgs Placement new arguments. 908/// \param PlacementRParen Closing paren of the placement arguments. 909/// \param TypeIdParens If the type is in parens, the source range. 910/// \param D The type to be allocated, as well as array dimensions. 911/// \param ConstructorLParen Opening paren of the constructor args, empty if 912/// initializer-list syntax is used. 913/// \param ConstructorArgs Constructor/initialization arguments. 914/// \param ConstructorRParen Closing paren of the constructor args. 915ExprResult 916Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal, 917 SourceLocation PlacementLParen, MultiExprArg PlacementArgs, 918 SourceLocation PlacementRParen, SourceRange TypeIdParens, 919 Declarator &D, Expr *Initializer) { 920 bool TypeContainsAuto = D.getDeclSpec().getTypeSpecType() == DeclSpec::TST_auto; 921 922 Expr *ArraySize = 0; 923 // If the specified type is an array, unwrap it and save the expression. 924 if (D.getNumTypeObjects() > 0 && 925 D.getTypeObject(0).Kind == DeclaratorChunk::Array) { 926 DeclaratorChunk &Chunk = D.getTypeObject(0); 927 if (TypeContainsAuto) 928 return ExprError(Diag(Chunk.Loc, diag::err_new_array_of_auto) 929 << D.getSourceRange()); 930 if (Chunk.Arr.hasStatic) 931 return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new) 932 << D.getSourceRange()); 933 if (!Chunk.Arr.NumElts) 934 return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size) 935 << D.getSourceRange()); 936 937 ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts); 938 D.DropFirstTypeObject(); 939 } 940 941 // Every dimension shall be of constant size. 942 if (ArraySize) { 943 for (unsigned I = 0, N = D.getNumTypeObjects(); I < N; ++I) { 944 if (D.getTypeObject(I).Kind != DeclaratorChunk::Array) 945 break; 946 947 DeclaratorChunk::ArrayTypeInfo &Array = D.getTypeObject(I).Arr; 948 if (Expr *NumElts = (Expr *)Array.NumElts) { 949 if (!NumElts->isTypeDependent() && !NumElts->isValueDependent()) { 950 Array.NumElts = VerifyIntegerConstantExpression(NumElts, 0, 951 PDiag(diag::err_new_array_nonconst)).take(); 952 if (!Array.NumElts) 953 return ExprError(); 954 } 955 } 956 } 957 } 958 959 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, /*Scope=*/0); 960 QualType AllocType = TInfo->getType(); 961 if (D.isInvalidType()) 962 return ExprError(); 963 964 SourceRange DirectInitRange; 965 if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) 966 DirectInitRange = List->getSourceRange(); 967 968 return BuildCXXNew(StartLoc, UseGlobal, 969 PlacementLParen, 970 move(PlacementArgs), 971 PlacementRParen, 972 TypeIdParens, 973 AllocType, 974 TInfo, 975 ArraySize, 976 DirectInitRange, 977 Initializer, 978 TypeContainsAuto); 979} 980 981static bool isLegalArrayNewInitializer(CXXNewExpr::InitializationStyle Style, 982 Expr *Init) { 983 if (!Init) 984 return true; 985 if (ParenListExpr *PLE = dyn_cast<ParenListExpr>(Init)) 986 return PLE->getNumExprs() == 0; 987 if (isa<ImplicitValueInitExpr>(Init)) 988 return true; 989 else if (CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init)) 990 return !CCE->isListInitialization() && 991 CCE->getConstructor()->isDefaultConstructor(); 992 else if (Style == CXXNewExpr::ListInit) { 993 assert(isa<InitListExpr>(Init) && 994 "Shouldn't create list CXXConstructExprs for arrays."); 995 return true; 996 } 997 return false; 998} 999 1000ExprResult 1001Sema::BuildCXXNew(SourceLocation StartLoc, bool UseGlobal, 1002 SourceLocation PlacementLParen, 1003 MultiExprArg PlacementArgs, 1004 SourceLocation PlacementRParen, 1005 SourceRange TypeIdParens, 1006 QualType AllocType, 1007 TypeSourceInfo *AllocTypeInfo, 1008 Expr *ArraySize, 1009 SourceRange DirectInitRange, 1010 Expr *Initializer, 1011 bool TypeMayContainAuto) { 1012 SourceRange TypeRange = AllocTypeInfo->getTypeLoc().getSourceRange(); 1013 1014 CXXNewExpr::InitializationStyle initStyle; 1015 if (DirectInitRange.isValid()) { 1016 assert(Initializer && "Have parens but no initializer."); 1017 initStyle = CXXNewExpr::CallInit; 1018 } else if (Initializer && isa<InitListExpr>(Initializer)) 1019 initStyle = CXXNewExpr::ListInit; 1020 else { 1021 // In template instantiation, the initializer could be a CXXDefaultArgExpr 1022 // unwrapped from a CXXConstructExpr that was implicitly built. There is no 1023 // particularly sane way we can handle this (especially since it can even 1024 // occur for array new), so we throw the initializer away and have it be 1025 // rebuilt. 1026 if (Initializer && isa<CXXDefaultArgExpr>(Initializer)) 1027 Initializer = 0; 1028 assert((!Initializer || isa<ImplicitValueInitExpr>(Initializer) || 1029 isa<CXXConstructExpr>(Initializer)) && 1030 "Initializer expression that cannot have been implicitly created."); 1031 initStyle = CXXNewExpr::NoInit; 1032 } 1033 1034 Expr **Inits = &Initializer; 1035 unsigned NumInits = Initializer ? 1 : 0; 1036 if (initStyle == CXXNewExpr::CallInit) { 1037 if (ParenListExpr *List = dyn_cast<ParenListExpr>(Initializer)) { 1038 Inits = List->getExprs(); 1039 NumInits = List->getNumExprs(); 1040 } else if (CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Initializer)){ 1041 if (!isa<CXXTemporaryObjectExpr>(CCE)) { 1042 // Can happen in template instantiation. Since this is just an implicit 1043 // construction, we just take it apart and rebuild it. 1044 Inits = CCE->getArgs(); 1045 NumInits = CCE->getNumArgs(); 1046 } 1047 } 1048 } 1049 1050 // C++0x [decl.spec.auto]p6. Deduce the type which 'auto' stands in for. 1051 if (TypeMayContainAuto && AllocType->getContainedAutoType()) { 1052 if (initStyle == CXXNewExpr::NoInit || NumInits == 0) 1053 return ExprError(Diag(StartLoc, diag::err_auto_new_requires_ctor_arg) 1054 << AllocType << TypeRange); 1055 if (initStyle == CXXNewExpr::ListInit) 1056 return ExprError(Diag(Inits[0]->getSourceRange().getBegin(), 1057 diag::err_auto_new_requires_parens) 1058 << AllocType << TypeRange); 1059 if (NumInits > 1) { 1060 Expr *FirstBad = Inits[1]; 1061 return ExprError(Diag(FirstBad->getSourceRange().getBegin(), 1062 diag::err_auto_new_ctor_multiple_expressions) 1063 << AllocType << TypeRange); 1064 } 1065 Expr *Deduce = Inits[0]; 1066 TypeSourceInfo *DeducedType = 0; 1067 if (DeduceAutoType(AllocTypeInfo, Deduce, DeducedType) == 1068 DAR_Failed) 1069 return ExprError(Diag(StartLoc, diag::err_auto_new_deduction_failure) 1070 << AllocType << Deduce->getType() 1071 << TypeRange << Deduce->getSourceRange()); 1072 if (!DeducedType) 1073 return ExprError(); 1074 1075 AllocTypeInfo = DeducedType; 1076 AllocType = AllocTypeInfo->getType(); 1077 } 1078 1079 // Per C++0x [expr.new]p5, the type being constructed may be a 1080 // typedef of an array type. 1081 if (!ArraySize) { 1082 if (const ConstantArrayType *Array 1083 = Context.getAsConstantArrayType(AllocType)) { 1084 ArraySize = IntegerLiteral::Create(Context, Array->getSize(), 1085 Context.getSizeType(), 1086 TypeRange.getEnd()); 1087 AllocType = Array->getElementType(); 1088 } 1089 } 1090 1091 if (CheckAllocatedType(AllocType, TypeRange.getBegin(), TypeRange)) 1092 return ExprError(); 1093 1094 if (initStyle == CXXNewExpr::ListInit && isStdInitializerList(AllocType, 0)) { 1095 Diag(AllocTypeInfo->getTypeLoc().getBeginLoc(), 1096 diag::warn_dangling_std_initializer_list) 1097 << /*at end of FE*/0 << Inits[0]->getSourceRange(); 1098 } 1099 1100 // In ARC, infer 'retaining' for the allocated 1101 if (getLangOptions().ObjCAutoRefCount && 1102 AllocType.getObjCLifetime() == Qualifiers::OCL_None && 1103 AllocType->isObjCLifetimeType()) { 1104 AllocType = Context.getLifetimeQualifiedType(AllocType, 1105 AllocType->getObjCARCImplicitLifetime()); 1106 } 1107 1108 QualType ResultType = Context.getPointerType(AllocType); 1109 1110 // C++98 5.3.4p6: "The expression in a direct-new-declarator shall have 1111 // integral or enumeration type with a non-negative value." 1112 // C++11 [expr.new]p6: The expression [...] shall be of integral or unscoped 1113 // enumeration type, or a class type for which a single non-explicit 1114 // conversion function to integral or unscoped enumeration type exists. 1115 if (ArraySize && !ArraySize->isTypeDependent()) { 1116 ExprResult ConvertedSize = ConvertToIntegralOrEnumerationType( 1117 StartLoc, ArraySize, 1118 PDiag(diag::err_array_size_not_integral) << getLangOptions().CPlusPlus0x, 1119 PDiag(diag::err_array_size_incomplete_type) 1120 << ArraySize->getSourceRange(), 1121 PDiag(diag::err_array_size_explicit_conversion), 1122 PDiag(diag::note_array_size_conversion), 1123 PDiag(diag::err_array_size_ambiguous_conversion), 1124 PDiag(diag::note_array_size_conversion), 1125 PDiag(getLangOptions().CPlusPlus0x ? 1126 diag::warn_cxx98_compat_array_size_conversion : 1127 diag::ext_array_size_conversion), 1128 /*AllowScopedEnumerations*/ false); 1129 if (ConvertedSize.isInvalid()) 1130 return ExprError(); 1131 1132 ArraySize = ConvertedSize.take(); 1133 QualType SizeType = ArraySize->getType(); 1134 if (!SizeType->isIntegralOrUnscopedEnumerationType()) 1135 return ExprError(); 1136 1137 // C++98 [expr.new]p7: 1138 // The expression in a direct-new-declarator shall have integral type 1139 // with a non-negative value. 1140 // 1141 // Let's see if this is a constant < 0. If so, we reject it out of 1142 // hand. Otherwise, if it's not a constant, we must have an unparenthesized 1143 // array type. 1144 // 1145 // Note: such a construct has well-defined semantics in C++11: it throws 1146 // std::bad_array_new_length. 1147 if (!ArraySize->isValueDependent()) { 1148 llvm::APSInt Value; 1149 // We've already performed any required implicit conversion to integer or 1150 // unscoped enumeration type. 1151 if (ArraySize->isIntegerConstantExpr(Value, Context)) { 1152 if (Value < llvm::APSInt( 1153 llvm::APInt::getNullValue(Value.getBitWidth()), 1154 Value.isUnsigned())) { 1155 if (getLangOptions().CPlusPlus0x) 1156 Diag(ArraySize->getSourceRange().getBegin(), 1157 diag::warn_typecheck_negative_array_new_size) 1158 << ArraySize->getSourceRange(); 1159 else 1160 return ExprError(Diag(ArraySize->getSourceRange().getBegin(), 1161 diag::err_typecheck_negative_array_size) 1162 << ArraySize->getSourceRange()); 1163 } else if (!AllocType->isDependentType()) { 1164 unsigned ActiveSizeBits = 1165 ConstantArrayType::getNumAddressingBits(Context, AllocType, Value); 1166 if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) { 1167 if (getLangOptions().CPlusPlus0x) 1168 Diag(ArraySize->getSourceRange().getBegin(), 1169 diag::warn_array_new_too_large) 1170 << Value.toString(10) 1171 << ArraySize->getSourceRange(); 1172 else 1173 return ExprError(Diag(ArraySize->getSourceRange().getBegin(), 1174 diag::err_array_too_large) 1175 << Value.toString(10) 1176 << ArraySize->getSourceRange()); 1177 } 1178 } 1179 } else if (TypeIdParens.isValid()) { 1180 // Can't have dynamic array size when the type-id is in parentheses. 1181 Diag(ArraySize->getLocStart(), diag::ext_new_paren_array_nonconst) 1182 << ArraySize->getSourceRange() 1183 << FixItHint::CreateRemoval(TypeIdParens.getBegin()) 1184 << FixItHint::CreateRemoval(TypeIdParens.getEnd()); 1185 1186 TypeIdParens = SourceRange(); 1187 } 1188 } 1189 1190 // ARC: warn about ABI issues. 1191 if (getLangOptions().ObjCAutoRefCount) { 1192 QualType BaseAllocType = Context.getBaseElementType(AllocType); 1193 if (BaseAllocType.hasStrongOrWeakObjCLifetime()) 1194 Diag(StartLoc, diag::warn_err_new_delete_object_array) 1195 << 0 << BaseAllocType; 1196 } 1197 1198 // Note that we do *not* convert the argument in any way. It can 1199 // be signed, larger than size_t, whatever. 1200 } 1201 1202 FunctionDecl *OperatorNew = 0; 1203 FunctionDecl *OperatorDelete = 0; 1204 Expr **PlaceArgs = (Expr**)PlacementArgs.get(); 1205 unsigned NumPlaceArgs = PlacementArgs.size(); 1206 1207 if (!AllocType->isDependentType() && 1208 !Expr::hasAnyTypeDependentArguments(PlaceArgs, NumPlaceArgs) && 1209 FindAllocationFunctions(StartLoc, 1210 SourceRange(PlacementLParen, PlacementRParen), 1211 UseGlobal, AllocType, ArraySize, PlaceArgs, 1212 NumPlaceArgs, OperatorNew, OperatorDelete)) 1213 return ExprError(); 1214 1215 // If this is an array allocation, compute whether the usual array 1216 // deallocation function for the type has a size_t parameter. 1217 bool UsualArrayDeleteWantsSize = false; 1218 if (ArraySize && !AllocType->isDependentType()) 1219 UsualArrayDeleteWantsSize 1220 = doesUsualArrayDeleteWantSize(*this, StartLoc, AllocType); 1221 1222 SmallVector<Expr *, 8> AllPlaceArgs; 1223 if (OperatorNew) { 1224 // Add default arguments, if any. 1225 const FunctionProtoType *Proto = 1226 OperatorNew->getType()->getAs<FunctionProtoType>(); 1227 VariadicCallType CallType = 1228 Proto->isVariadic() ? VariadicFunction : VariadicDoesNotApply; 1229 1230 if (GatherArgumentsForCall(PlacementLParen, OperatorNew, 1231 Proto, 1, PlaceArgs, NumPlaceArgs, 1232 AllPlaceArgs, CallType)) 1233 return ExprError(); 1234 1235 NumPlaceArgs = AllPlaceArgs.size(); 1236 if (NumPlaceArgs > 0) 1237 PlaceArgs = &AllPlaceArgs[0]; 1238 1239 DiagnoseSentinelCalls(OperatorNew, PlacementLParen, 1240 PlaceArgs, NumPlaceArgs); 1241 1242 // FIXME: Missing call to CheckFunctionCall or equivalent 1243 } 1244 1245 // Warn if the type is over-aligned and is being allocated by global operator 1246 // new. 1247 if (NumPlaceArgs == 0 && OperatorNew && 1248 (OperatorNew->isImplicit() || 1249 getSourceManager().isInSystemHeader(OperatorNew->getLocStart()))) { 1250 if (unsigned Align = Context.getPreferredTypeAlign(AllocType.getTypePtr())){ 1251 unsigned SuitableAlign = Context.getTargetInfo().getSuitableAlign(); 1252 if (Align > SuitableAlign) 1253 Diag(StartLoc, diag::warn_overaligned_type) 1254 << AllocType 1255 << unsigned(Align / Context.getCharWidth()) 1256 << unsigned(SuitableAlign / Context.getCharWidth()); 1257 } 1258 } 1259 1260 QualType InitType = AllocType; 1261 // Array 'new' can't have any initializers except empty parentheses. 1262 // Initializer lists are also allowed, in C++11. Rely on the parser for the 1263 // dialect distinction. 1264 if (ResultType->isArrayType() || ArraySize) { 1265 if (!isLegalArrayNewInitializer(initStyle, Initializer)) { 1266 SourceRange InitRange(Inits[0]->getLocStart(), 1267 Inits[NumInits - 1]->getLocEnd()); 1268 Diag(StartLoc, diag::err_new_array_init_args) << InitRange; 1269 return ExprError(); 1270 } 1271 if (InitListExpr *ILE = dyn_cast_or_null<InitListExpr>(Initializer)) { 1272 // We do the initialization typechecking against the array type 1273 // corresponding to the number of initializers + 1 (to also check 1274 // default-initialization). 1275 unsigned NumElements = ILE->getNumInits() + 1; 1276 InitType = Context.getConstantArrayType(AllocType, 1277 llvm::APInt(Context.getTypeSize(Context.getSizeType()), NumElements), 1278 ArrayType::Normal, 0); 1279 } 1280 } 1281 1282 if (!AllocType->isDependentType() && 1283 !Expr::hasAnyTypeDependentArguments(Inits, NumInits)) { 1284 // C++11 [expr.new]p15: 1285 // A new-expression that creates an object of type T initializes that 1286 // object as follows: 1287 InitializationKind Kind 1288 // - If the new-initializer is omitted, the object is default- 1289 // initialized (8.5); if no initialization is performed, 1290 // the object has indeterminate value 1291 = initStyle == CXXNewExpr::NoInit 1292 ? InitializationKind::CreateDefault(TypeRange.getBegin()) 1293 // - Otherwise, the new-initializer is interpreted according to the 1294 // initialization rules of 8.5 for direct-initialization. 1295 : initStyle == CXXNewExpr::ListInit 1296 ? InitializationKind::CreateDirectList(TypeRange.getBegin()) 1297 : InitializationKind::CreateDirect(TypeRange.getBegin(), 1298 DirectInitRange.getBegin(), 1299 DirectInitRange.getEnd()); 1300 1301 InitializedEntity Entity 1302 = InitializedEntity::InitializeNew(StartLoc, InitType); 1303 InitializationSequence InitSeq(*this, Entity, Kind, Inits, NumInits); 1304 ExprResult FullInit = InitSeq.Perform(*this, Entity, Kind, 1305 MultiExprArg(Inits, NumInits)); 1306 if (FullInit.isInvalid()) 1307 return ExprError(); 1308 1309 // FullInit is our initializer; strip off CXXBindTemporaryExprs, because 1310 // we don't want the initialized object to be destructed. 1311 if (CXXBindTemporaryExpr *Binder = 1312 dyn_cast_or_null<CXXBindTemporaryExpr>(FullInit.get())) 1313 FullInit = Owned(Binder->getSubExpr()); 1314 1315 Initializer = FullInit.take(); 1316 } 1317 1318 // Mark the new and delete operators as referenced. 1319 if (OperatorNew) 1320 MarkFunctionReferenced(StartLoc, OperatorNew); 1321 if (OperatorDelete) 1322 MarkFunctionReferenced(StartLoc, OperatorDelete); 1323 1324 // C++0x [expr.new]p17: 1325 // If the new expression creates an array of objects of class type, 1326 // access and ambiguity control are done for the destructor. 1327 if (ArraySize && AllocType->isRecordType() && !AllocType->isDependentType()) { 1328 if (CXXDestructorDecl *dtor = LookupDestructor( 1329 cast<CXXRecordDecl>(AllocType->getAs<RecordType>()->getDecl()))) { 1330 MarkFunctionReferenced(StartLoc, dtor); 1331 CheckDestructorAccess(StartLoc, dtor, 1332 PDiag(diag::err_access_dtor) 1333 << Context.getBaseElementType(AllocType)); 1334 DiagnoseUseOfDecl(dtor, StartLoc); 1335 } 1336 } 1337 1338 PlacementArgs.release(); 1339 1340 return Owned(new (Context) CXXNewExpr(Context, UseGlobal, OperatorNew, 1341 OperatorDelete, 1342 UsualArrayDeleteWantsSize, 1343 PlaceArgs, NumPlaceArgs, TypeIdParens, 1344 ArraySize, initStyle, Initializer, 1345 ResultType, AllocTypeInfo, 1346 StartLoc, DirectInitRange)); 1347} 1348 1349/// \brief Checks that a type is suitable as the allocated type 1350/// in a new-expression. 1351bool Sema::CheckAllocatedType(QualType AllocType, SourceLocation Loc, 1352 SourceRange R) { 1353 // C++ 5.3.4p1: "[The] type shall be a complete object type, but not an 1354 // abstract class type or array thereof. 1355 if (AllocType->isFunctionType()) 1356 return Diag(Loc, diag::err_bad_new_type) 1357 << AllocType << 0 << R; 1358 else if (AllocType->isReferenceType()) 1359 return Diag(Loc, diag::err_bad_new_type) 1360 << AllocType << 1 << R; 1361 else if (!AllocType->isDependentType() && 1362 RequireCompleteType(Loc, AllocType, 1363 PDiag(diag::err_new_incomplete_type) 1364 << R)) 1365 return true; 1366 else if (RequireNonAbstractType(Loc, AllocType, 1367 diag::err_allocation_of_abstract_type)) 1368 return true; 1369 else if (AllocType->isVariablyModifiedType()) 1370 return Diag(Loc, diag::err_variably_modified_new_type) 1371 << AllocType; 1372 else if (unsigned AddressSpace = AllocType.getAddressSpace()) 1373 return Diag(Loc, diag::err_address_space_qualified_new) 1374 << AllocType.getUnqualifiedType() << AddressSpace; 1375 else if (getLangOptions().ObjCAutoRefCount) { 1376 if (const ArrayType *AT = Context.getAsArrayType(AllocType)) { 1377 QualType BaseAllocType = Context.getBaseElementType(AT); 1378 if (BaseAllocType.getObjCLifetime() == Qualifiers::OCL_None && 1379 BaseAllocType->isObjCLifetimeType()) 1380 return Diag(Loc, diag::err_arc_new_array_without_ownership) 1381 << BaseAllocType; 1382 } 1383 } 1384 1385 return false; 1386} 1387 1388/// \brief Determine whether the given function is a non-placement 1389/// deallocation function. 1390static bool isNonPlacementDeallocationFunction(FunctionDecl *FD) { 1391 if (FD->isInvalidDecl()) 1392 return false; 1393 1394 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD)) 1395 return Method->isUsualDeallocationFunction(); 1396 1397 return ((FD->getOverloadedOperator() == OO_Delete || 1398 FD->getOverloadedOperator() == OO_Array_Delete) && 1399 FD->getNumParams() == 1); 1400} 1401 1402/// FindAllocationFunctions - Finds the overloads of operator new and delete 1403/// that are appropriate for the allocation. 1404bool Sema::FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range, 1405 bool UseGlobal, QualType AllocType, 1406 bool IsArray, Expr **PlaceArgs, 1407 unsigned NumPlaceArgs, 1408 FunctionDecl *&OperatorNew, 1409 FunctionDecl *&OperatorDelete) { 1410 // --- Choosing an allocation function --- 1411 // C++ 5.3.4p8 - 14 & 18 1412 // 1) If UseGlobal is true, only look in the global scope. Else, also look 1413 // in the scope of the allocated class. 1414 // 2) If an array size is given, look for operator new[], else look for 1415 // operator new. 1416 // 3) The first argument is always size_t. Append the arguments from the 1417 // placement form. 1418 1419 SmallVector<Expr*, 8> AllocArgs(1 + NumPlaceArgs); 1420 // We don't care about the actual value of this argument. 1421 // FIXME: Should the Sema create the expression and embed it in the syntax 1422 // tree? Or should the consumer just recalculate the value? 1423 IntegerLiteral Size(Context, llvm::APInt::getNullValue( 1424 Context.getTargetInfo().getPointerWidth(0)), 1425 Context.getSizeType(), 1426 SourceLocation()); 1427 AllocArgs[0] = &Size; 1428 std::copy(PlaceArgs, PlaceArgs + NumPlaceArgs, AllocArgs.begin() + 1); 1429 1430 // C++ [expr.new]p8: 1431 // If the allocated type is a non-array type, the allocation 1432 // function's name is operator new and the deallocation function's 1433 // name is operator delete. If the allocated type is an array 1434 // type, the allocation function's name is operator new[] and the 1435 // deallocation function's name is operator delete[]. 1436 DeclarationName NewName = Context.DeclarationNames.getCXXOperatorName( 1437 IsArray ? OO_Array_New : OO_New); 1438 DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName( 1439 IsArray ? OO_Array_Delete : OO_Delete); 1440 1441 QualType AllocElemType = Context.getBaseElementType(AllocType); 1442 1443 if (AllocElemType->isRecordType() && !UseGlobal) { 1444 CXXRecordDecl *Record 1445 = cast<CXXRecordDecl>(AllocElemType->getAs<RecordType>()->getDecl()); 1446 if (FindAllocationOverload(StartLoc, Range, NewName, &AllocArgs[0], 1447 AllocArgs.size(), Record, /*AllowMissing=*/true, 1448 OperatorNew)) 1449 return true; 1450 } 1451 if (!OperatorNew) { 1452 // Didn't find a member overload. Look for a global one. 1453 DeclareGlobalNewDelete(); 1454 DeclContext *TUDecl = Context.getTranslationUnitDecl(); 1455 if (FindAllocationOverload(StartLoc, Range, NewName, &AllocArgs[0], 1456 AllocArgs.size(), TUDecl, /*AllowMissing=*/false, 1457 OperatorNew)) 1458 return true; 1459 } 1460 1461 // We don't need an operator delete if we're running under 1462 // -fno-exceptions. 1463 if (!getLangOptions().Exceptions) { 1464 OperatorDelete = 0; 1465 return false; 1466 } 1467 1468 // FindAllocationOverload can change the passed in arguments, so we need to 1469 // copy them back. 1470 if (NumPlaceArgs > 0) 1471 std::copy(&AllocArgs[1], AllocArgs.end(), PlaceArgs); 1472 1473 // C++ [expr.new]p19: 1474 // 1475 // If the new-expression begins with a unary :: operator, the 1476 // deallocation function's name is looked up in the global 1477 // scope. Otherwise, if the allocated type is a class type T or an 1478 // array thereof, the deallocation function's name is looked up in 1479 // the scope of T. If this lookup fails to find the name, or if 1480 // the allocated type is not a class type or array thereof, the 1481 // deallocation function's name is looked up in the global scope. 1482 LookupResult FoundDelete(*this, DeleteName, StartLoc, LookupOrdinaryName); 1483 if (AllocElemType->isRecordType() && !UseGlobal) { 1484 CXXRecordDecl *RD 1485 = cast<CXXRecordDecl>(AllocElemType->getAs<RecordType>()->getDecl()); 1486 LookupQualifiedName(FoundDelete, RD); 1487 } 1488 if (FoundDelete.isAmbiguous()) 1489 return true; // FIXME: clean up expressions? 1490 1491 if (FoundDelete.empty()) { 1492 DeclareGlobalNewDelete(); 1493 LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl()); 1494 } 1495 1496 FoundDelete.suppressDiagnostics(); 1497 1498 SmallVector<std::pair<DeclAccessPair,FunctionDecl*>, 2> Matches; 1499 1500 // Whether we're looking for a placement operator delete is dictated 1501 // by whether we selected a placement operator new, not by whether 1502 // we had explicit placement arguments. This matters for things like 1503 // struct A { void *operator new(size_t, int = 0); ... }; 1504 // A *a = new A() 1505 bool isPlacementNew = (NumPlaceArgs > 0 || OperatorNew->param_size() != 1); 1506 1507 if (isPlacementNew) { 1508 // C++ [expr.new]p20: 1509 // A declaration of a placement deallocation function matches the 1510 // declaration of a placement allocation function if it has the 1511 // same number of parameters and, after parameter transformations 1512 // (8.3.5), all parameter types except the first are 1513 // identical. [...] 1514 // 1515 // To perform this comparison, we compute the function type that 1516 // the deallocation function should have, and use that type both 1517 // for template argument deduction and for comparison purposes. 1518 // 1519 // FIXME: this comparison should ignore CC and the like. 1520 QualType ExpectedFunctionType; 1521 { 1522 const FunctionProtoType *Proto 1523 = OperatorNew->getType()->getAs<FunctionProtoType>(); 1524 1525 SmallVector<QualType, 4> ArgTypes; 1526 ArgTypes.push_back(Context.VoidPtrTy); 1527 for (unsigned I = 1, N = Proto->getNumArgs(); I < N; ++I) 1528 ArgTypes.push_back(Proto->getArgType(I)); 1529 1530 FunctionProtoType::ExtProtoInfo EPI; 1531 EPI.Variadic = Proto->isVariadic(); 1532 1533 ExpectedFunctionType 1534 = Context.getFunctionType(Context.VoidTy, ArgTypes.data(), 1535 ArgTypes.size(), EPI); 1536 } 1537 1538 for (LookupResult::iterator D = FoundDelete.begin(), 1539 DEnd = FoundDelete.end(); 1540 D != DEnd; ++D) { 1541 FunctionDecl *Fn = 0; 1542 if (FunctionTemplateDecl *FnTmpl 1543 = dyn_cast<FunctionTemplateDecl>((*D)->getUnderlyingDecl())) { 1544 // Perform template argument deduction to try to match the 1545 // expected function type. 1546 TemplateDeductionInfo Info(Context, StartLoc); 1547 if (DeduceTemplateArguments(FnTmpl, 0, ExpectedFunctionType, Fn, Info)) 1548 continue; 1549 } else 1550 Fn = cast<FunctionDecl>((*D)->getUnderlyingDecl()); 1551 1552 if (Context.hasSameType(Fn->getType(), ExpectedFunctionType)) 1553 Matches.push_back(std::make_pair(D.getPair(), Fn)); 1554 } 1555 } else { 1556 // C++ [expr.new]p20: 1557 // [...] Any non-placement deallocation function matches a 1558 // non-placement allocation function. [...] 1559 for (LookupResult::iterator D = FoundDelete.begin(), 1560 DEnd = FoundDelete.end(); 1561 D != DEnd; ++D) { 1562 if (FunctionDecl *Fn = dyn_cast<FunctionDecl>((*D)->getUnderlyingDecl())) 1563 if (isNonPlacementDeallocationFunction(Fn)) 1564 Matches.push_back(std::make_pair(D.getPair(), Fn)); 1565 } 1566 } 1567 1568 // C++ [expr.new]p20: 1569 // [...] If the lookup finds a single matching deallocation 1570 // function, that function will be called; otherwise, no 1571 // deallocation function will be called. 1572 if (Matches.size() == 1) { 1573 OperatorDelete = Matches[0].second; 1574 1575 // C++0x [expr.new]p20: 1576 // If the lookup finds the two-parameter form of a usual 1577 // deallocation function (3.7.4.2) and that function, considered 1578 // as a placement deallocation function, would have been 1579 // selected as a match for the allocation function, the program 1580 // is ill-formed. 1581 if (NumPlaceArgs && getLangOptions().CPlusPlus0x && 1582 isNonPlacementDeallocationFunction(OperatorDelete)) { 1583 Diag(StartLoc, diag::err_placement_new_non_placement_delete) 1584 << SourceRange(PlaceArgs[0]->getLocStart(), 1585 PlaceArgs[NumPlaceArgs - 1]->getLocEnd()); 1586 Diag(OperatorDelete->getLocation(), diag::note_previous_decl) 1587 << DeleteName; 1588 } else { 1589 CheckAllocationAccess(StartLoc, Range, FoundDelete.getNamingClass(), 1590 Matches[0].first); 1591 } 1592 } 1593 1594 return false; 1595} 1596 1597/// FindAllocationOverload - Find an fitting overload for the allocation 1598/// function in the specified scope. 1599bool Sema::FindAllocationOverload(SourceLocation StartLoc, SourceRange Range, 1600 DeclarationName Name, Expr** Args, 1601 unsigned NumArgs, DeclContext *Ctx, 1602 bool AllowMissing, FunctionDecl *&Operator, 1603 bool Diagnose) { 1604 LookupResult R(*this, Name, StartLoc, LookupOrdinaryName); 1605 LookupQualifiedName(R, Ctx); 1606 if (R.empty()) { 1607 if (AllowMissing || !Diagnose) 1608 return false; 1609 return Diag(StartLoc, diag::err_ovl_no_viable_function_in_call) 1610 << Name << Range; 1611 } 1612 1613 if (R.isAmbiguous()) 1614 return true; 1615 1616 R.suppressDiagnostics(); 1617 1618 OverloadCandidateSet Candidates(StartLoc); 1619 for (LookupResult::iterator Alloc = R.begin(), AllocEnd = R.end(); 1620 Alloc != AllocEnd; ++Alloc) { 1621 // Even member operator new/delete are implicitly treated as 1622 // static, so don't use AddMemberCandidate. 1623 NamedDecl *D = (*Alloc)->getUnderlyingDecl(); 1624 1625 if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) { 1626 AddTemplateOverloadCandidate(FnTemplate, Alloc.getPair(), 1627 /*ExplicitTemplateArgs=*/0, Args, NumArgs, 1628 Candidates, 1629 /*SuppressUserConversions=*/false); 1630 continue; 1631 } 1632 1633 FunctionDecl *Fn = cast<FunctionDecl>(D); 1634 AddOverloadCandidate(Fn, Alloc.getPair(), Args, NumArgs, Candidates, 1635 /*SuppressUserConversions=*/false); 1636 } 1637 1638 // Do the resolution. 1639 OverloadCandidateSet::iterator Best; 1640 switch (Candidates.BestViableFunction(*this, StartLoc, Best)) { 1641 case OR_Success: { 1642 // Got one! 1643 FunctionDecl *FnDecl = Best->Function; 1644 MarkFunctionReferenced(StartLoc, FnDecl); 1645 // The first argument is size_t, and the first parameter must be size_t, 1646 // too. This is checked on declaration and can be assumed. (It can't be 1647 // asserted on, though, since invalid decls are left in there.) 1648 // Watch out for variadic allocator function. 1649 unsigned NumArgsInFnDecl = FnDecl->getNumParams(); 1650 for (unsigned i = 0; (i < NumArgs && i < NumArgsInFnDecl); ++i) { 1651 InitializedEntity Entity = InitializedEntity::InitializeParameter(Context, 1652 FnDecl->getParamDecl(i)); 1653 1654 if (!Diagnose && !CanPerformCopyInitialization(Entity, Owned(Args[i]))) 1655 return true; 1656 1657 ExprResult Result 1658 = PerformCopyInitialization(Entity, SourceLocation(), Owned(Args[i])); 1659 if (Result.isInvalid()) 1660 return true; 1661 1662 Args[i] = Result.takeAs<Expr>(); 1663 } 1664 Operator = FnDecl; 1665 CheckAllocationAccess(StartLoc, Range, R.getNamingClass(), Best->FoundDecl, 1666 Diagnose); 1667 return false; 1668 } 1669 1670 case OR_No_Viable_Function: 1671 if (Diagnose) { 1672 Diag(StartLoc, diag::err_ovl_no_viable_function_in_call) 1673 << Name << Range; 1674 Candidates.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 1675 } 1676 return true; 1677 1678 case OR_Ambiguous: 1679 if (Diagnose) { 1680 Diag(StartLoc, diag::err_ovl_ambiguous_call) 1681 << Name << Range; 1682 Candidates.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 1683 } 1684 return true; 1685 1686 case OR_Deleted: { 1687 if (Diagnose) { 1688 Diag(StartLoc, diag::err_ovl_deleted_call) 1689 << Best->Function->isDeleted() 1690 << Name 1691 << getDeletedOrUnavailableSuffix(Best->Function) 1692 << Range; 1693 Candidates.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 1694 } 1695 return true; 1696 } 1697 } 1698 llvm_unreachable("Unreachable, bad result from BestViableFunction"); 1699} 1700 1701 1702/// DeclareGlobalNewDelete - Declare the global forms of operator new and 1703/// delete. These are: 1704/// @code 1705/// // C++03: 1706/// void* operator new(std::size_t) throw(std::bad_alloc); 1707/// void* operator new[](std::size_t) throw(std::bad_alloc); 1708/// void operator delete(void *) throw(); 1709/// void operator delete[](void *) throw(); 1710/// // C++0x: 1711/// void* operator new(std::size_t); 1712/// void* operator new[](std::size_t); 1713/// void operator delete(void *); 1714/// void operator delete[](void *); 1715/// @endcode 1716/// C++0x operator delete is implicitly noexcept. 1717/// Note that the placement and nothrow forms of new are *not* implicitly 1718/// declared. Their use requires including \<new\>. 1719void Sema::DeclareGlobalNewDelete() { 1720 if (GlobalNewDeleteDeclared) 1721 return; 1722 1723 // C++ [basic.std.dynamic]p2: 1724 // [...] The following allocation and deallocation functions (18.4) are 1725 // implicitly declared in global scope in each translation unit of a 1726 // program 1727 // 1728 // C++03: 1729 // void* operator new(std::size_t) throw(std::bad_alloc); 1730 // void* operator new[](std::size_t) throw(std::bad_alloc); 1731 // void operator delete(void*) throw(); 1732 // void operator delete[](void*) throw(); 1733 // C++0x: 1734 // void* operator new(std::size_t); 1735 // void* operator new[](std::size_t); 1736 // void operator delete(void*); 1737 // void operator delete[](void*); 1738 // 1739 // These implicit declarations introduce only the function names operator 1740 // new, operator new[], operator delete, operator delete[]. 1741 // 1742 // Here, we need to refer to std::bad_alloc, so we will implicitly declare 1743 // "std" or "bad_alloc" as necessary to form the exception specification. 1744 // However, we do not make these implicit declarations visible to name 1745 // lookup. 1746 // Note that the C++0x versions of operator delete are deallocation functions, 1747 // and thus are implicitly noexcept. 1748 if (!StdBadAlloc && !getLangOptions().CPlusPlus0x) { 1749 // The "std::bad_alloc" class has not yet been declared, so build it 1750 // implicitly. 1751 StdBadAlloc = CXXRecordDecl::Create(Context, TTK_Class, 1752 getOrCreateStdNamespace(), 1753 SourceLocation(), SourceLocation(), 1754 &PP.getIdentifierTable().get("bad_alloc"), 1755 0); 1756 getStdBadAlloc()->setImplicit(true); 1757 } 1758 1759 GlobalNewDeleteDeclared = true; 1760 1761 QualType VoidPtr = Context.getPointerType(Context.VoidTy); 1762 QualType SizeT = Context.getSizeType(); 1763 bool AssumeSaneOperatorNew = getLangOptions().AssumeSaneOperatorNew; 1764 1765 DeclareGlobalAllocationFunction( 1766 Context.DeclarationNames.getCXXOperatorName(OO_New), 1767 VoidPtr, SizeT, AssumeSaneOperatorNew); 1768 DeclareGlobalAllocationFunction( 1769 Context.DeclarationNames.getCXXOperatorName(OO_Array_New), 1770 VoidPtr, SizeT, AssumeSaneOperatorNew); 1771 DeclareGlobalAllocationFunction( 1772 Context.DeclarationNames.getCXXOperatorName(OO_Delete), 1773 Context.VoidTy, VoidPtr); 1774 DeclareGlobalAllocationFunction( 1775 Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete), 1776 Context.VoidTy, VoidPtr); 1777} 1778 1779/// DeclareGlobalAllocationFunction - Declares a single implicit global 1780/// allocation function if it doesn't already exist. 1781void Sema::DeclareGlobalAllocationFunction(DeclarationName Name, 1782 QualType Return, QualType Argument, 1783 bool AddMallocAttr) { 1784 DeclContext *GlobalCtx = Context.getTranslationUnitDecl(); 1785 1786 // Check if this function is already declared. 1787 { 1788 DeclContext::lookup_iterator Alloc, AllocEnd; 1789 for (llvm::tie(Alloc, AllocEnd) = GlobalCtx->lookup(Name); 1790 Alloc != AllocEnd; ++Alloc) { 1791 // Only look at non-template functions, as it is the predefined, 1792 // non-templated allocation function we are trying to declare here. 1793 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(*Alloc)) { 1794 QualType InitialParamType = 1795 Context.getCanonicalType( 1796 Func->getParamDecl(0)->getType().getUnqualifiedType()); 1797 // FIXME: Do we need to check for default arguments here? 1798 if (Func->getNumParams() == 1 && InitialParamType == Argument) { 1799 if(AddMallocAttr && !Func->hasAttr<MallocAttr>()) 1800 Func->addAttr(::new (Context) MallocAttr(SourceLocation(), Context)); 1801 return; 1802 } 1803 } 1804 } 1805 } 1806 1807 QualType BadAllocType; 1808 bool HasBadAllocExceptionSpec 1809 = (Name.getCXXOverloadedOperator() == OO_New || 1810 Name.getCXXOverloadedOperator() == OO_Array_New); 1811 if (HasBadAllocExceptionSpec && !getLangOptions().CPlusPlus0x) { 1812 assert(StdBadAlloc && "Must have std::bad_alloc declared"); 1813 BadAllocType = Context.getTypeDeclType(getStdBadAlloc()); 1814 } 1815 1816 FunctionProtoType::ExtProtoInfo EPI; 1817 if (HasBadAllocExceptionSpec) { 1818 if (!getLangOptions().CPlusPlus0x) { 1819 EPI.ExceptionSpecType = EST_Dynamic; 1820 EPI.NumExceptions = 1; 1821 EPI.Exceptions = &BadAllocType; 1822 } 1823 } else { 1824 EPI.ExceptionSpecType = getLangOptions().CPlusPlus0x ? 1825 EST_BasicNoexcept : EST_DynamicNone; 1826 } 1827 1828 QualType FnType = Context.getFunctionType(Return, &Argument, 1, EPI); 1829 FunctionDecl *Alloc = 1830 FunctionDecl::Create(Context, GlobalCtx, SourceLocation(), 1831 SourceLocation(), Name, 1832 FnType, /*TInfo=*/0, SC_None, 1833 SC_None, false, true); 1834 Alloc->setImplicit(); 1835 1836 if (AddMallocAttr) 1837 Alloc->addAttr(::new (Context) MallocAttr(SourceLocation(), Context)); 1838 1839 ParmVarDecl *Param = ParmVarDecl::Create(Context, Alloc, SourceLocation(), 1840 SourceLocation(), 0, 1841 Argument, /*TInfo=*/0, 1842 SC_None, SC_None, 0); 1843 Alloc->setParams(Param); 1844 1845 // FIXME: Also add this declaration to the IdentifierResolver, but 1846 // make sure it is at the end of the chain to coincide with the 1847 // global scope. 1848 Context.getTranslationUnitDecl()->addDecl(Alloc); 1849} 1850 1851bool Sema::FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD, 1852 DeclarationName Name, 1853 FunctionDecl* &Operator, bool Diagnose) { 1854 LookupResult Found(*this, Name, StartLoc, LookupOrdinaryName); 1855 // Try to find operator delete/operator delete[] in class scope. 1856 LookupQualifiedName(Found, RD); 1857 1858 if (Found.isAmbiguous()) 1859 return true; 1860 1861 Found.suppressDiagnostics(); 1862 1863 SmallVector<DeclAccessPair,4> Matches; 1864 for (LookupResult::iterator F = Found.begin(), FEnd = Found.end(); 1865 F != FEnd; ++F) { 1866 NamedDecl *ND = (*F)->getUnderlyingDecl(); 1867 1868 // Ignore template operator delete members from the check for a usual 1869 // deallocation function. 1870 if (isa<FunctionTemplateDecl>(ND)) 1871 continue; 1872 1873 if (cast<CXXMethodDecl>(ND)->isUsualDeallocationFunction()) 1874 Matches.push_back(F.getPair()); 1875 } 1876 1877 // There's exactly one suitable operator; pick it. 1878 if (Matches.size() == 1) { 1879 Operator = cast<CXXMethodDecl>(Matches[0]->getUnderlyingDecl()); 1880 1881 if (Operator->isDeleted()) { 1882 if (Diagnose) { 1883 Diag(StartLoc, diag::err_deleted_function_use); 1884 Diag(Operator->getLocation(), diag::note_unavailable_here) 1885 << /*function*/ 1 << /*deleted*/ 1; 1886 } 1887 return true; 1888 } 1889 1890 CheckAllocationAccess(StartLoc, SourceRange(), Found.getNamingClass(), 1891 Matches[0], Diagnose); 1892 return false; 1893 1894 // We found multiple suitable operators; complain about the ambiguity. 1895 } else if (!Matches.empty()) { 1896 if (Diagnose) { 1897 Diag(StartLoc, diag::err_ambiguous_suitable_delete_member_function_found) 1898 << Name << RD; 1899 1900 for (SmallVectorImpl<DeclAccessPair>::iterator 1901 F = Matches.begin(), FEnd = Matches.end(); F != FEnd; ++F) 1902 Diag((*F)->getUnderlyingDecl()->getLocation(), 1903 diag::note_member_declared_here) << Name; 1904 } 1905 return true; 1906 } 1907 1908 // We did find operator delete/operator delete[] declarations, but 1909 // none of them were suitable. 1910 if (!Found.empty()) { 1911 if (Diagnose) { 1912 Diag(StartLoc, diag::err_no_suitable_delete_member_function_found) 1913 << Name << RD; 1914 1915 for (LookupResult::iterator F = Found.begin(), FEnd = Found.end(); 1916 F != FEnd; ++F) 1917 Diag((*F)->getUnderlyingDecl()->getLocation(), 1918 diag::note_member_declared_here) << Name; 1919 } 1920 return true; 1921 } 1922 1923 // Look for a global declaration. 1924 DeclareGlobalNewDelete(); 1925 DeclContext *TUDecl = Context.getTranslationUnitDecl(); 1926 1927 CXXNullPtrLiteralExpr Null(Context.VoidPtrTy, SourceLocation()); 1928 Expr* DeallocArgs[1]; 1929 DeallocArgs[0] = &Null; 1930 if (FindAllocationOverload(StartLoc, SourceRange(), Name, 1931 DeallocArgs, 1, TUDecl, !Diagnose, 1932 Operator, Diagnose)) 1933 return true; 1934 1935 assert(Operator && "Did not find a deallocation function!"); 1936 return false; 1937} 1938 1939/// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in: 1940/// @code ::delete ptr; @endcode 1941/// or 1942/// @code delete [] ptr; @endcode 1943ExprResult 1944Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal, 1945 bool ArrayForm, Expr *ExE) { 1946 // C++ [expr.delete]p1: 1947 // The operand shall have a pointer type, or a class type having a single 1948 // conversion function to a pointer type. The result has type void. 1949 // 1950 // DR599 amends "pointer type" to "pointer to object type" in both cases. 1951 1952 ExprResult Ex = Owned(ExE); 1953 FunctionDecl *OperatorDelete = 0; 1954 bool ArrayFormAsWritten = ArrayForm; 1955 bool UsualArrayDeleteWantsSize = false; 1956 1957 if (!Ex.get()->isTypeDependent()) { 1958 QualType Type = Ex.get()->getType(); 1959 1960 if (const RecordType *Record = Type->getAs<RecordType>()) { 1961 if (RequireCompleteType(StartLoc, Type, 1962 PDiag(diag::err_delete_incomplete_class_type))) 1963 return ExprError(); 1964 1965 SmallVector<CXXConversionDecl*, 4> ObjectPtrConversions; 1966 1967 CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl()); 1968 const UnresolvedSetImpl *Conversions = RD->getVisibleConversionFunctions(); 1969 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1970 E = Conversions->end(); I != E; ++I) { 1971 NamedDecl *D = I.getDecl(); 1972 if (isa<UsingShadowDecl>(D)) 1973 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1974 1975 // Skip over templated conversion functions; they aren't considered. 1976 if (isa<FunctionTemplateDecl>(D)) 1977 continue; 1978 1979 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 1980 1981 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 1982 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 1983 if (ConvPtrType->getPointeeType()->isIncompleteOrObjectType()) 1984 ObjectPtrConversions.push_back(Conv); 1985 } 1986 if (ObjectPtrConversions.size() == 1) { 1987 // We have a single conversion to a pointer-to-object type. Perform 1988 // that conversion. 1989 // TODO: don't redo the conversion calculation. 1990 ExprResult Res = 1991 PerformImplicitConversion(Ex.get(), 1992 ObjectPtrConversions.front()->getConversionType(), 1993 AA_Converting); 1994 if (Res.isUsable()) { 1995 Ex = move(Res); 1996 Type = Ex.get()->getType(); 1997 } 1998 } 1999 else if (ObjectPtrConversions.size() > 1) { 2000 Diag(StartLoc, diag::err_ambiguous_delete_operand) 2001 << Type << Ex.get()->getSourceRange(); 2002 for (unsigned i= 0; i < ObjectPtrConversions.size(); i++) 2003 NoteOverloadCandidate(ObjectPtrConversions[i]); 2004 return ExprError(); 2005 } 2006 } 2007 2008 if (!Type->isPointerType()) 2009 return ExprError(Diag(StartLoc, diag::err_delete_operand) 2010 << Type << Ex.get()->getSourceRange()); 2011 2012 QualType Pointee = Type->getAs<PointerType>()->getPointeeType(); 2013 QualType PointeeElem = Context.getBaseElementType(Pointee); 2014 2015 if (unsigned AddressSpace = Pointee.getAddressSpace()) 2016 return Diag(Ex.get()->getLocStart(), 2017 diag::err_address_space_qualified_delete) 2018 << Pointee.getUnqualifiedType() << AddressSpace; 2019 2020 CXXRecordDecl *PointeeRD = 0; 2021 if (Pointee->isVoidType() && !isSFINAEContext()) { 2022 // The C++ standard bans deleting a pointer to a non-object type, which 2023 // effectively bans deletion of "void*". However, most compilers support 2024 // this, so we treat it as a warning unless we're in a SFINAE context. 2025 Diag(StartLoc, diag::ext_delete_void_ptr_operand) 2026 << Type << Ex.get()->getSourceRange(); 2027 } else if (Pointee->isFunctionType() || Pointee->isVoidType()) { 2028 return ExprError(Diag(StartLoc, diag::err_delete_operand) 2029 << Type << Ex.get()->getSourceRange()); 2030 } else if (!Pointee->isDependentType()) { 2031 if (!RequireCompleteType(StartLoc, Pointee, 2032 PDiag(diag::warn_delete_incomplete) 2033 << Ex.get()->getSourceRange())) { 2034 if (const RecordType *RT = PointeeElem->getAs<RecordType>()) 2035 PointeeRD = cast<CXXRecordDecl>(RT->getDecl()); 2036 } 2037 } 2038 2039 // Perform lvalue-to-rvalue cast, if needed. 2040 Ex = DefaultLvalueConversion(Ex.take()); 2041 2042 // C++ [expr.delete]p2: 2043 // [Note: a pointer to a const type can be the operand of a 2044 // delete-expression; it is not necessary to cast away the constness 2045 // (5.2.11) of the pointer expression before it is used as the operand 2046 // of the delete-expression. ] 2047 if (!Context.hasSameType(Ex.get()->getType(), Context.VoidPtrTy)) 2048 Ex = Owned(ImplicitCastExpr::Create(Context, Context.VoidPtrTy, 2049 CK_BitCast, Ex.take(), 0, VK_RValue)); 2050 2051 if (Pointee->isArrayType() && !ArrayForm) { 2052 Diag(StartLoc, diag::warn_delete_array_type) 2053 << Type << Ex.get()->getSourceRange() 2054 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(StartLoc), "[]"); 2055 ArrayForm = true; 2056 } 2057 2058 DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName( 2059 ArrayForm ? OO_Array_Delete : OO_Delete); 2060 2061 if (PointeeRD) { 2062 if (!UseGlobal && 2063 FindDeallocationFunction(StartLoc, PointeeRD, DeleteName, 2064 OperatorDelete)) 2065 return ExprError(); 2066 2067 // If we're allocating an array of records, check whether the 2068 // usual operator delete[] has a size_t parameter. 2069 if (ArrayForm) { 2070 // If the user specifically asked to use the global allocator, 2071 // we'll need to do the lookup into the class. 2072 if (UseGlobal) 2073 UsualArrayDeleteWantsSize = 2074 doesUsualArrayDeleteWantSize(*this, StartLoc, PointeeElem); 2075 2076 // Otherwise, the usual operator delete[] should be the 2077 // function we just found. 2078 else if (isa<CXXMethodDecl>(OperatorDelete)) 2079 UsualArrayDeleteWantsSize = (OperatorDelete->getNumParams() == 2); 2080 } 2081 2082 if (!PointeeRD->hasIrrelevantDestructor()) 2083 if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) { 2084 MarkFunctionReferenced(StartLoc, 2085 const_cast<CXXDestructorDecl*>(Dtor)); 2086 DiagnoseUseOfDecl(Dtor, StartLoc); 2087 } 2088 2089 // C++ [expr.delete]p3: 2090 // In the first alternative (delete object), if the static type of the 2091 // object to be deleted is different from its dynamic type, the static 2092 // type shall be a base class of the dynamic type of the object to be 2093 // deleted and the static type shall have a virtual destructor or the 2094 // behavior is undefined. 2095 // 2096 // Note: a final class cannot be derived from, no issue there 2097 if (PointeeRD->isPolymorphic() && !PointeeRD->hasAttr<FinalAttr>()) { 2098 CXXDestructorDecl *dtor = PointeeRD->getDestructor(); 2099 if (dtor && !dtor->isVirtual()) { 2100 if (PointeeRD->isAbstract()) { 2101 // If the class is abstract, we warn by default, because we're 2102 // sure the code has undefined behavior. 2103 Diag(StartLoc, diag::warn_delete_abstract_non_virtual_dtor) 2104 << PointeeElem; 2105 } else if (!ArrayForm) { 2106 // Otherwise, if this is not an array delete, it's a bit suspect, 2107 // but not necessarily wrong. 2108 Diag(StartLoc, diag::warn_delete_non_virtual_dtor) << PointeeElem; 2109 } 2110 } 2111 } 2112 2113 } else if (getLangOptions().ObjCAutoRefCount && 2114 PointeeElem->isObjCLifetimeType() && 2115 (PointeeElem.getObjCLifetime() == Qualifiers::OCL_Strong || 2116 PointeeElem.getObjCLifetime() == Qualifiers::OCL_Weak) && 2117 ArrayForm) { 2118 Diag(StartLoc, diag::warn_err_new_delete_object_array) 2119 << 1 << PointeeElem; 2120 } 2121 2122 if (!OperatorDelete) { 2123 // Look for a global declaration. 2124 DeclareGlobalNewDelete(); 2125 DeclContext *TUDecl = Context.getTranslationUnitDecl(); 2126 Expr *Arg = Ex.get(); 2127 if (FindAllocationOverload(StartLoc, SourceRange(), DeleteName, 2128 &Arg, 1, TUDecl, /*AllowMissing=*/false, 2129 OperatorDelete)) 2130 return ExprError(); 2131 } 2132 2133 MarkFunctionReferenced(StartLoc, OperatorDelete); 2134 2135 // Check access and ambiguity of operator delete and destructor. 2136 if (PointeeRD) { 2137 if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) { 2138 CheckDestructorAccess(Ex.get()->getExprLoc(), Dtor, 2139 PDiag(diag::err_access_dtor) << PointeeElem); 2140 } 2141 } 2142 2143 } 2144 2145 return Owned(new (Context) CXXDeleteExpr(Context.VoidTy, UseGlobal, ArrayForm, 2146 ArrayFormAsWritten, 2147 UsualArrayDeleteWantsSize, 2148 OperatorDelete, Ex.take(), StartLoc)); 2149} 2150 2151/// \brief Check the use of the given variable as a C++ condition in an if, 2152/// while, do-while, or switch statement. 2153ExprResult Sema::CheckConditionVariable(VarDecl *ConditionVar, 2154 SourceLocation StmtLoc, 2155 bool ConvertToBoolean) { 2156 QualType T = ConditionVar->getType(); 2157 2158 // C++ [stmt.select]p2: 2159 // The declarator shall not specify a function or an array. 2160 if (T->isFunctionType()) 2161 return ExprError(Diag(ConditionVar->getLocation(), 2162 diag::err_invalid_use_of_function_type) 2163 << ConditionVar->getSourceRange()); 2164 else if (T->isArrayType()) 2165 return ExprError(Diag(ConditionVar->getLocation(), 2166 diag::err_invalid_use_of_array_type) 2167 << ConditionVar->getSourceRange()); 2168 2169 ExprResult Condition = 2170 Owned(DeclRefExpr::Create(Context, NestedNameSpecifierLoc(), 2171 SourceLocation(), 2172 ConditionVar, 2173 ConditionVar->getLocation(), 2174 ConditionVar->getType().getNonReferenceType(), 2175 VK_LValue)); 2176 2177 MarkDeclRefReferenced(cast<DeclRefExpr>(Condition.get())); 2178 2179 if (ConvertToBoolean) { 2180 Condition = CheckBooleanCondition(Condition.take(), StmtLoc); 2181 if (Condition.isInvalid()) 2182 return ExprError(); 2183 } 2184 2185 return move(Condition); 2186} 2187 2188/// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid. 2189ExprResult Sema::CheckCXXBooleanCondition(Expr *CondExpr) { 2190 // C++ 6.4p4: 2191 // The value of a condition that is an initialized declaration in a statement 2192 // other than a switch statement is the value of the declared variable 2193 // implicitly converted to type bool. If that conversion is ill-formed, the 2194 // program is ill-formed. 2195 // The value of a condition that is an expression is the value of the 2196 // expression, implicitly converted to bool. 2197 // 2198 return PerformContextuallyConvertToBool(CondExpr); 2199} 2200 2201/// Helper function to determine whether this is the (deprecated) C++ 2202/// conversion from a string literal to a pointer to non-const char or 2203/// non-const wchar_t (for narrow and wide string literals, 2204/// respectively). 2205bool 2206Sema::IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType) { 2207 // Look inside the implicit cast, if it exists. 2208 if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From)) 2209 From = Cast->getSubExpr(); 2210 2211 // A string literal (2.13.4) that is not a wide string literal can 2212 // be converted to an rvalue of type "pointer to char"; a wide 2213 // string literal can be converted to an rvalue of type "pointer 2214 // to wchar_t" (C++ 4.2p2). 2215 if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From->IgnoreParens())) 2216 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) 2217 if (const BuiltinType *ToPointeeType 2218 = ToPtrType->getPointeeType()->getAs<BuiltinType>()) { 2219 // This conversion is considered only when there is an 2220 // explicit appropriate pointer target type (C++ 4.2p2). 2221 if (!ToPtrType->getPointeeType().hasQualifiers()) { 2222 switch (StrLit->getKind()) { 2223 case StringLiteral::UTF8: 2224 case StringLiteral::UTF16: 2225 case StringLiteral::UTF32: 2226 // We don't allow UTF literals to be implicitly converted 2227 break; 2228 case StringLiteral::Ascii: 2229 return (ToPointeeType->getKind() == BuiltinType::Char_U || 2230 ToPointeeType->getKind() == BuiltinType::Char_S); 2231 case StringLiteral::Wide: 2232 return ToPointeeType->isWideCharType(); 2233 } 2234 } 2235 } 2236 2237 return false; 2238} 2239 2240static ExprResult BuildCXXCastArgument(Sema &S, 2241 SourceLocation CastLoc, 2242 QualType Ty, 2243 CastKind Kind, 2244 CXXMethodDecl *Method, 2245 DeclAccessPair FoundDecl, 2246 bool HadMultipleCandidates, 2247 Expr *From) { 2248 switch (Kind) { 2249 default: llvm_unreachable("Unhandled cast kind!"); 2250 case CK_ConstructorConversion: { 2251 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Method); 2252 ASTOwningVector<Expr*> ConstructorArgs(S); 2253 2254 if (S.CompleteConstructorCall(Constructor, 2255 MultiExprArg(&From, 1), 2256 CastLoc, ConstructorArgs)) 2257 return ExprError(); 2258 2259 S.CheckConstructorAccess(CastLoc, Constructor, Constructor->getAccess(), 2260 S.PDiag(diag::err_access_ctor)); 2261 2262 ExprResult Result 2263 = S.BuildCXXConstructExpr(CastLoc, Ty, cast<CXXConstructorDecl>(Method), 2264 move_arg(ConstructorArgs), 2265 HadMultipleCandidates, /*ZeroInit*/ false, 2266 CXXConstructExpr::CK_Complete, SourceRange()); 2267 if (Result.isInvalid()) 2268 return ExprError(); 2269 2270 return S.MaybeBindToTemporary(Result.takeAs<Expr>()); 2271 } 2272 2273 case CK_UserDefinedConversion: { 2274 assert(!From->getType()->isPointerType() && "Arg can't have pointer type!"); 2275 2276 // Create an implicit call expr that calls it. 2277 ExprResult Result = S.BuildCXXMemberCallExpr(From, FoundDecl, Method, 2278 HadMultipleCandidates); 2279 if (Result.isInvalid()) 2280 return ExprError(); 2281 // Record usage of conversion in an implicit cast. 2282 Result = S.Owned(ImplicitCastExpr::Create(S.Context, 2283 Result.get()->getType(), 2284 CK_UserDefinedConversion, 2285 Result.get(), 0, 2286 Result.get()->getValueKind())); 2287 2288 S.CheckMemberOperatorAccess(CastLoc, From, /*arg*/ 0, FoundDecl); 2289 2290 return S.MaybeBindToTemporary(Result.get()); 2291 } 2292 } 2293} 2294 2295/// PerformImplicitConversion - Perform an implicit conversion of the 2296/// expression From to the type ToType using the pre-computed implicit 2297/// conversion sequence ICS. Returns the converted 2298/// expression. Action is the kind of conversion we're performing, 2299/// used in the error message. 2300ExprResult 2301Sema::PerformImplicitConversion(Expr *From, QualType ToType, 2302 const ImplicitConversionSequence &ICS, 2303 AssignmentAction Action, 2304 CheckedConversionKind CCK) { 2305 switch (ICS.getKind()) { 2306 case ImplicitConversionSequence::StandardConversion: { 2307 ExprResult Res = PerformImplicitConversion(From, ToType, ICS.Standard, 2308 Action, CCK); 2309 if (Res.isInvalid()) 2310 return ExprError(); 2311 From = Res.take(); 2312 break; 2313 } 2314 2315 case ImplicitConversionSequence::UserDefinedConversion: { 2316 2317 FunctionDecl *FD = ICS.UserDefined.ConversionFunction; 2318 CastKind CastKind; 2319 QualType BeforeToType; 2320 assert(FD && "FIXME: aggregate initialization from init list"); 2321 if (const CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(FD)) { 2322 CastKind = CK_UserDefinedConversion; 2323 2324 // If the user-defined conversion is specified by a conversion function, 2325 // the initial standard conversion sequence converts the source type to 2326 // the implicit object parameter of the conversion function. 2327 BeforeToType = Context.getTagDeclType(Conv->getParent()); 2328 } else { 2329 const CXXConstructorDecl *Ctor = cast<CXXConstructorDecl>(FD); 2330 CastKind = CK_ConstructorConversion; 2331 // Do no conversion if dealing with ... for the first conversion. 2332 if (!ICS.UserDefined.EllipsisConversion) { 2333 // If the user-defined conversion is specified by a constructor, the 2334 // initial standard conversion sequence converts the source type to the 2335 // type required by the argument of the constructor 2336 BeforeToType = Ctor->getParamDecl(0)->getType().getNonReferenceType(); 2337 } 2338 } 2339 // Watch out for elipsis conversion. 2340 if (!ICS.UserDefined.EllipsisConversion) { 2341 ExprResult Res = 2342 PerformImplicitConversion(From, BeforeToType, 2343 ICS.UserDefined.Before, AA_Converting, 2344 CCK); 2345 if (Res.isInvalid()) 2346 return ExprError(); 2347 From = Res.take(); 2348 } 2349 2350 ExprResult CastArg 2351 = BuildCXXCastArgument(*this, 2352 From->getLocStart(), 2353 ToType.getNonReferenceType(), 2354 CastKind, cast<CXXMethodDecl>(FD), 2355 ICS.UserDefined.FoundConversionFunction, 2356 ICS.UserDefined.HadMultipleCandidates, 2357 From); 2358 2359 if (CastArg.isInvalid()) 2360 return ExprError(); 2361 2362 From = CastArg.take(); 2363 2364 return PerformImplicitConversion(From, ToType, ICS.UserDefined.After, 2365 AA_Converting, CCK); 2366 } 2367 2368 case ImplicitConversionSequence::AmbiguousConversion: 2369 ICS.DiagnoseAmbiguousConversion(*this, From->getExprLoc(), 2370 PDiag(diag::err_typecheck_ambiguous_condition) 2371 << From->getSourceRange()); 2372 return ExprError(); 2373 2374 case ImplicitConversionSequence::EllipsisConversion: 2375 llvm_unreachable("Cannot perform an ellipsis conversion"); 2376 2377 case ImplicitConversionSequence::BadConversion: 2378 return ExprError(); 2379 } 2380 2381 // Everything went well. 2382 return Owned(From); 2383} 2384 2385/// PerformImplicitConversion - Perform an implicit conversion of the 2386/// expression From to the type ToType by following the standard 2387/// conversion sequence SCS. Returns the converted 2388/// expression. Flavor is the context in which we're performing this 2389/// conversion, for use in error messages. 2390ExprResult 2391Sema::PerformImplicitConversion(Expr *From, QualType ToType, 2392 const StandardConversionSequence& SCS, 2393 AssignmentAction Action, 2394 CheckedConversionKind CCK) { 2395 bool CStyle = (CCK == CCK_CStyleCast || CCK == CCK_FunctionalCast); 2396 2397 // Overall FIXME: we are recomputing too many types here and doing far too 2398 // much extra work. What this means is that we need to keep track of more 2399 // information that is computed when we try the implicit conversion initially, 2400 // so that we don't need to recompute anything here. 2401 QualType FromType = From->getType(); 2402 2403 if (SCS.CopyConstructor) { 2404 // FIXME: When can ToType be a reference type? 2405 assert(!ToType->isReferenceType()); 2406 if (SCS.Second == ICK_Derived_To_Base) { 2407 ASTOwningVector<Expr*> ConstructorArgs(*this); 2408 if (CompleteConstructorCall(cast<CXXConstructorDecl>(SCS.CopyConstructor), 2409 MultiExprArg(*this, &From, 1), 2410 /*FIXME:ConstructLoc*/SourceLocation(), 2411 ConstructorArgs)) 2412 return ExprError(); 2413 return BuildCXXConstructExpr(/*FIXME:ConstructLoc*/SourceLocation(), 2414 ToType, SCS.CopyConstructor, 2415 move_arg(ConstructorArgs), 2416 /*HadMultipleCandidates*/ false, 2417 /*ZeroInit*/ false, 2418 CXXConstructExpr::CK_Complete, 2419 SourceRange()); 2420 } 2421 return BuildCXXConstructExpr(/*FIXME:ConstructLoc*/SourceLocation(), 2422 ToType, SCS.CopyConstructor, 2423 MultiExprArg(*this, &From, 1), 2424 /*HadMultipleCandidates*/ false, 2425 /*ZeroInit*/ false, 2426 CXXConstructExpr::CK_Complete, 2427 SourceRange()); 2428 } 2429 2430 // Resolve overloaded function references. 2431 if (Context.hasSameType(FromType, Context.OverloadTy)) { 2432 DeclAccessPair Found; 2433 FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(From, ToType, 2434 true, Found); 2435 if (!Fn) 2436 return ExprError(); 2437 2438 if (DiagnoseUseOfDecl(Fn, From->getSourceRange().getBegin())) 2439 return ExprError(); 2440 2441 From = FixOverloadedFunctionReference(From, Found, Fn); 2442 FromType = From->getType(); 2443 } 2444 2445 // Perform the first implicit conversion. 2446 switch (SCS.First) { 2447 case ICK_Identity: 2448 // Nothing to do. 2449 break; 2450 2451 case ICK_Lvalue_To_Rvalue: { 2452 assert(From->getObjectKind() != OK_ObjCProperty); 2453 FromType = FromType.getUnqualifiedType(); 2454 ExprResult FromRes = DefaultLvalueConversion(From); 2455 assert(!FromRes.isInvalid() && "Can't perform deduced conversion?!"); 2456 From = FromRes.take(); 2457 break; 2458 } 2459 2460 case ICK_Array_To_Pointer: 2461 FromType = Context.getArrayDecayedType(FromType); 2462 From = ImpCastExprToType(From, FromType, CK_ArrayToPointerDecay, 2463 VK_RValue, /*BasePath=*/0, CCK).take(); 2464 break; 2465 2466 case ICK_Function_To_Pointer: 2467 FromType = Context.getPointerType(FromType); 2468 From = ImpCastExprToType(From, FromType, CK_FunctionToPointerDecay, 2469 VK_RValue, /*BasePath=*/0, CCK).take(); 2470 break; 2471 2472 default: 2473 llvm_unreachable("Improper first standard conversion"); 2474 } 2475 2476 // Perform the second implicit conversion 2477 switch (SCS.Second) { 2478 case ICK_Identity: 2479 // If both sides are functions (or pointers/references to them), there could 2480 // be incompatible exception declarations. 2481 if (CheckExceptionSpecCompatibility(From, ToType)) 2482 return ExprError(); 2483 // Nothing else to do. 2484 break; 2485 2486 case ICK_NoReturn_Adjustment: 2487 // If both sides are functions (or pointers/references to them), there could 2488 // be incompatible exception declarations. 2489 if (CheckExceptionSpecCompatibility(From, ToType)) 2490 return ExprError(); 2491 2492 From = ImpCastExprToType(From, ToType, CK_NoOp, 2493 VK_RValue, /*BasePath=*/0, CCK).take(); 2494 break; 2495 2496 case ICK_Integral_Promotion: 2497 case ICK_Integral_Conversion: 2498 From = ImpCastExprToType(From, ToType, CK_IntegralCast, 2499 VK_RValue, /*BasePath=*/0, CCK).take(); 2500 break; 2501 2502 case ICK_Floating_Promotion: 2503 case ICK_Floating_Conversion: 2504 From = ImpCastExprToType(From, ToType, CK_FloatingCast, 2505 VK_RValue, /*BasePath=*/0, CCK).take(); 2506 break; 2507 2508 case ICK_Complex_Promotion: 2509 case ICK_Complex_Conversion: { 2510 QualType FromEl = From->getType()->getAs<ComplexType>()->getElementType(); 2511 QualType ToEl = ToType->getAs<ComplexType>()->getElementType(); 2512 CastKind CK; 2513 if (FromEl->isRealFloatingType()) { 2514 if (ToEl->isRealFloatingType()) 2515 CK = CK_FloatingComplexCast; 2516 else 2517 CK = CK_FloatingComplexToIntegralComplex; 2518 } else if (ToEl->isRealFloatingType()) { 2519 CK = CK_IntegralComplexToFloatingComplex; 2520 } else { 2521 CK = CK_IntegralComplexCast; 2522 } 2523 From = ImpCastExprToType(From, ToType, CK, 2524 VK_RValue, /*BasePath=*/0, CCK).take(); 2525 break; 2526 } 2527 2528 case ICK_Floating_Integral: 2529 if (ToType->isRealFloatingType()) 2530 From = ImpCastExprToType(From, ToType, CK_IntegralToFloating, 2531 VK_RValue, /*BasePath=*/0, CCK).take(); 2532 else 2533 From = ImpCastExprToType(From, ToType, CK_FloatingToIntegral, 2534 VK_RValue, /*BasePath=*/0, CCK).take(); 2535 break; 2536 2537 case ICK_Compatible_Conversion: 2538 From = ImpCastExprToType(From, ToType, CK_NoOp, 2539 VK_RValue, /*BasePath=*/0, CCK).take(); 2540 break; 2541 2542 case ICK_Writeback_Conversion: 2543 case ICK_Pointer_Conversion: { 2544 if (SCS.IncompatibleObjC && Action != AA_Casting) { 2545 // Diagnose incompatible Objective-C conversions 2546 if (Action == AA_Initializing || Action == AA_Assigning) 2547 Diag(From->getSourceRange().getBegin(), 2548 diag::ext_typecheck_convert_incompatible_pointer) 2549 << ToType << From->getType() << Action 2550 << From->getSourceRange() << 0; 2551 else 2552 Diag(From->getSourceRange().getBegin(), 2553 diag::ext_typecheck_convert_incompatible_pointer) 2554 << From->getType() << ToType << Action 2555 << From->getSourceRange() << 0; 2556 2557 if (From->getType()->isObjCObjectPointerType() && 2558 ToType->isObjCObjectPointerType()) 2559 EmitRelatedResultTypeNote(From); 2560 } 2561 else if (getLangOptions().ObjCAutoRefCount && 2562 !CheckObjCARCUnavailableWeakConversion(ToType, 2563 From->getType())) { 2564 if (Action == AA_Initializing) 2565 Diag(From->getSourceRange().getBegin(), 2566 diag::err_arc_weak_unavailable_assign); 2567 else 2568 Diag(From->getSourceRange().getBegin(), 2569 diag::err_arc_convesion_of_weak_unavailable) 2570 << (Action == AA_Casting) << From->getType() << ToType 2571 << From->getSourceRange(); 2572 } 2573 2574 CastKind Kind = CK_Invalid; 2575 CXXCastPath BasePath; 2576 if (CheckPointerConversion(From, ToType, Kind, BasePath, CStyle)) 2577 return ExprError(); 2578 2579 // Make sure we extend blocks if necessary. 2580 // FIXME: doing this here is really ugly. 2581 if (Kind == CK_BlockPointerToObjCPointerCast) { 2582 ExprResult E = From; 2583 (void) PrepareCastToObjCObjectPointer(E); 2584 From = E.take(); 2585 } 2586 2587 From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK) 2588 .take(); 2589 break; 2590 } 2591 2592 case ICK_Pointer_Member: { 2593 CastKind Kind = CK_Invalid; 2594 CXXCastPath BasePath; 2595 if (CheckMemberPointerConversion(From, ToType, Kind, BasePath, CStyle)) 2596 return ExprError(); 2597 if (CheckExceptionSpecCompatibility(From, ToType)) 2598 return ExprError(); 2599 From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK) 2600 .take(); 2601 break; 2602 } 2603 2604 case ICK_Boolean_Conversion: 2605 // Perform half-to-boolean conversion via float. 2606 if (From->getType()->isHalfType()) { 2607 From = ImpCastExprToType(From, Context.FloatTy, CK_FloatingCast).take(); 2608 FromType = Context.FloatTy; 2609 } 2610 2611 From = ImpCastExprToType(From, Context.BoolTy, 2612 ScalarTypeToBooleanCastKind(FromType), 2613 VK_RValue, /*BasePath=*/0, CCK).take(); 2614 break; 2615 2616 case ICK_Derived_To_Base: { 2617 CXXCastPath BasePath; 2618 if (CheckDerivedToBaseConversion(From->getType(), 2619 ToType.getNonReferenceType(), 2620 From->getLocStart(), 2621 From->getSourceRange(), 2622 &BasePath, 2623 CStyle)) 2624 return ExprError(); 2625 2626 From = ImpCastExprToType(From, ToType.getNonReferenceType(), 2627 CK_DerivedToBase, From->getValueKind(), 2628 &BasePath, CCK).take(); 2629 break; 2630 } 2631 2632 case ICK_Vector_Conversion: 2633 From = ImpCastExprToType(From, ToType, CK_BitCast, 2634 VK_RValue, /*BasePath=*/0, CCK).take(); 2635 break; 2636 2637 case ICK_Vector_Splat: 2638 From = ImpCastExprToType(From, ToType, CK_VectorSplat, 2639 VK_RValue, /*BasePath=*/0, CCK).take(); 2640 break; 2641 2642 case ICK_Complex_Real: 2643 // Case 1. x -> _Complex y 2644 if (const ComplexType *ToComplex = ToType->getAs<ComplexType>()) { 2645 QualType ElType = ToComplex->getElementType(); 2646 bool isFloatingComplex = ElType->isRealFloatingType(); 2647 2648 // x -> y 2649 if (Context.hasSameUnqualifiedType(ElType, From->getType())) { 2650 // do nothing 2651 } else if (From->getType()->isRealFloatingType()) { 2652 From = ImpCastExprToType(From, ElType, 2653 isFloatingComplex ? CK_FloatingCast : CK_FloatingToIntegral).take(); 2654 } else { 2655 assert(From->getType()->isIntegerType()); 2656 From = ImpCastExprToType(From, ElType, 2657 isFloatingComplex ? CK_IntegralToFloating : CK_IntegralCast).take(); 2658 } 2659 // y -> _Complex y 2660 From = ImpCastExprToType(From, ToType, 2661 isFloatingComplex ? CK_FloatingRealToComplex 2662 : CK_IntegralRealToComplex).take(); 2663 2664 // Case 2. _Complex x -> y 2665 } else { 2666 const ComplexType *FromComplex = From->getType()->getAs<ComplexType>(); 2667 assert(FromComplex); 2668 2669 QualType ElType = FromComplex->getElementType(); 2670 bool isFloatingComplex = ElType->isRealFloatingType(); 2671 2672 // _Complex x -> x 2673 From = ImpCastExprToType(From, ElType, 2674 isFloatingComplex ? CK_FloatingComplexToReal 2675 : CK_IntegralComplexToReal, 2676 VK_RValue, /*BasePath=*/0, CCK).take(); 2677 2678 // x -> y 2679 if (Context.hasSameUnqualifiedType(ElType, ToType)) { 2680 // do nothing 2681 } else if (ToType->isRealFloatingType()) { 2682 From = ImpCastExprToType(From, ToType, 2683 isFloatingComplex ? CK_FloatingCast : CK_IntegralToFloating, 2684 VK_RValue, /*BasePath=*/0, CCK).take(); 2685 } else { 2686 assert(ToType->isIntegerType()); 2687 From = ImpCastExprToType(From, ToType, 2688 isFloatingComplex ? CK_FloatingToIntegral : CK_IntegralCast, 2689 VK_RValue, /*BasePath=*/0, CCK).take(); 2690 } 2691 } 2692 break; 2693 2694 case ICK_Block_Pointer_Conversion: { 2695 From = ImpCastExprToType(From, ToType.getUnqualifiedType(), CK_BitCast, 2696 VK_RValue, /*BasePath=*/0, CCK).take(); 2697 break; 2698 } 2699 2700 case ICK_TransparentUnionConversion: { 2701 ExprResult FromRes = Owned(From); 2702 Sema::AssignConvertType ConvTy = 2703 CheckTransparentUnionArgumentConstraints(ToType, FromRes); 2704 if (FromRes.isInvalid()) 2705 return ExprError(); 2706 From = FromRes.take(); 2707 assert ((ConvTy == Sema::Compatible) && 2708 "Improper transparent union conversion"); 2709 (void)ConvTy; 2710 break; 2711 } 2712 2713 case ICK_Lvalue_To_Rvalue: 2714 case ICK_Array_To_Pointer: 2715 case ICK_Function_To_Pointer: 2716 case ICK_Qualification: 2717 case ICK_Num_Conversion_Kinds: 2718 llvm_unreachable("Improper second standard conversion"); 2719 } 2720 2721 switch (SCS.Third) { 2722 case ICK_Identity: 2723 // Nothing to do. 2724 break; 2725 2726 case ICK_Qualification: { 2727 // The qualification keeps the category of the inner expression, unless the 2728 // target type isn't a reference. 2729 ExprValueKind VK = ToType->isReferenceType() ? 2730 From->getValueKind() : VK_RValue; 2731 From = ImpCastExprToType(From, ToType.getNonLValueExprType(Context), 2732 CK_NoOp, VK, /*BasePath=*/0, CCK).take(); 2733 2734 if (SCS.DeprecatedStringLiteralToCharPtr && 2735 !getLangOptions().WritableStrings) 2736 Diag(From->getLocStart(), diag::warn_deprecated_string_literal_conversion) 2737 << ToType.getNonReferenceType(); 2738 2739 break; 2740 } 2741 2742 default: 2743 llvm_unreachable("Improper third standard conversion"); 2744 } 2745 2746 return Owned(From); 2747} 2748 2749ExprResult Sema::ActOnUnaryTypeTrait(UnaryTypeTrait UTT, 2750 SourceLocation KWLoc, 2751 ParsedType Ty, 2752 SourceLocation RParen) { 2753 TypeSourceInfo *TSInfo; 2754 QualType T = GetTypeFromParser(Ty, &TSInfo); 2755 2756 if (!TSInfo) 2757 TSInfo = Context.getTrivialTypeSourceInfo(T); 2758 return BuildUnaryTypeTrait(UTT, KWLoc, TSInfo, RParen); 2759} 2760 2761/// \brief Check the completeness of a type in a unary type trait. 2762/// 2763/// If the particular type trait requires a complete type, tries to complete 2764/// it. If completing the type fails, a diagnostic is emitted and false 2765/// returned. If completing the type succeeds or no completion was required, 2766/// returns true. 2767static bool CheckUnaryTypeTraitTypeCompleteness(Sema &S, 2768 UnaryTypeTrait UTT, 2769 SourceLocation Loc, 2770 QualType ArgTy) { 2771 // C++0x [meta.unary.prop]p3: 2772 // For all of the class templates X declared in this Clause, instantiating 2773 // that template with a template argument that is a class template 2774 // specialization may result in the implicit instantiation of the template 2775 // argument if and only if the semantics of X require that the argument 2776 // must be a complete type. 2777 // We apply this rule to all the type trait expressions used to implement 2778 // these class templates. We also try to follow any GCC documented behavior 2779 // in these expressions to ensure portability of standard libraries. 2780 switch (UTT) { 2781 // is_complete_type somewhat obviously cannot require a complete type. 2782 case UTT_IsCompleteType: 2783 // Fall-through 2784 2785 // These traits are modeled on the type predicates in C++0x 2786 // [meta.unary.cat] and [meta.unary.comp]. They are not specified as 2787 // requiring a complete type, as whether or not they return true cannot be 2788 // impacted by the completeness of the type. 2789 case UTT_IsVoid: 2790 case UTT_IsIntegral: 2791 case UTT_IsFloatingPoint: 2792 case UTT_IsArray: 2793 case UTT_IsPointer: 2794 case UTT_IsLvalueReference: 2795 case UTT_IsRvalueReference: 2796 case UTT_IsMemberFunctionPointer: 2797 case UTT_IsMemberObjectPointer: 2798 case UTT_IsEnum: 2799 case UTT_IsUnion: 2800 case UTT_IsClass: 2801 case UTT_IsFunction: 2802 case UTT_IsReference: 2803 case UTT_IsArithmetic: 2804 case UTT_IsFundamental: 2805 case UTT_IsObject: 2806 case UTT_IsScalar: 2807 case UTT_IsCompound: 2808 case UTT_IsMemberPointer: 2809 // Fall-through 2810 2811 // These traits are modeled on type predicates in C++0x [meta.unary.prop] 2812 // which requires some of its traits to have the complete type. However, 2813 // the completeness of the type cannot impact these traits' semantics, and 2814 // so they don't require it. This matches the comments on these traits in 2815 // Table 49. 2816 case UTT_IsConst: 2817 case UTT_IsVolatile: 2818 case UTT_IsSigned: 2819 case UTT_IsUnsigned: 2820 return true; 2821 2822 // C++0x [meta.unary.prop] Table 49 requires the following traits to be 2823 // applied to a complete type. 2824 case UTT_IsTrivial: 2825 case UTT_IsTriviallyCopyable: 2826 case UTT_IsStandardLayout: 2827 case UTT_IsPOD: 2828 case UTT_IsLiteral: 2829 case UTT_IsEmpty: 2830 case UTT_IsPolymorphic: 2831 case UTT_IsAbstract: 2832 // Fall-through 2833 2834 // These traits require a complete type. 2835 case UTT_IsFinal: 2836 2837 // These trait expressions are designed to help implement predicates in 2838 // [meta.unary.prop] despite not being named the same. They are specified 2839 // by both GCC and the Embarcadero C++ compiler, and require the complete 2840 // type due to the overarching C++0x type predicates being implemented 2841 // requiring the complete type. 2842 case UTT_HasNothrowAssign: 2843 case UTT_HasNothrowConstructor: 2844 case UTT_HasNothrowCopy: 2845 case UTT_HasTrivialAssign: 2846 case UTT_HasTrivialDefaultConstructor: 2847 case UTT_HasTrivialCopy: 2848 case UTT_HasTrivialDestructor: 2849 case UTT_HasVirtualDestructor: 2850 // Arrays of unknown bound are expressly allowed. 2851 QualType ElTy = ArgTy; 2852 if (ArgTy->isIncompleteArrayType()) 2853 ElTy = S.Context.getAsArrayType(ArgTy)->getElementType(); 2854 2855 // The void type is expressly allowed. 2856 if (ElTy->isVoidType()) 2857 return true; 2858 2859 return !S.RequireCompleteType( 2860 Loc, ElTy, diag::err_incomplete_type_used_in_type_trait_expr); 2861 } 2862 llvm_unreachable("Type trait not handled by switch"); 2863} 2864 2865static bool EvaluateUnaryTypeTrait(Sema &Self, UnaryTypeTrait UTT, 2866 SourceLocation KeyLoc, QualType T) { 2867 assert(!T->isDependentType() && "Cannot evaluate traits of dependent type"); 2868 2869 ASTContext &C = Self.Context; 2870 switch(UTT) { 2871 // Type trait expressions corresponding to the primary type category 2872 // predicates in C++0x [meta.unary.cat]. 2873 case UTT_IsVoid: 2874 return T->isVoidType(); 2875 case UTT_IsIntegral: 2876 return T->isIntegralType(C); 2877 case UTT_IsFloatingPoint: 2878 return T->isFloatingType(); 2879 case UTT_IsArray: 2880 return T->isArrayType(); 2881 case UTT_IsPointer: 2882 return T->isPointerType(); 2883 case UTT_IsLvalueReference: 2884 return T->isLValueReferenceType(); 2885 case UTT_IsRvalueReference: 2886 return T->isRValueReferenceType(); 2887 case UTT_IsMemberFunctionPointer: 2888 return T->isMemberFunctionPointerType(); 2889 case UTT_IsMemberObjectPointer: 2890 return T->isMemberDataPointerType(); 2891 case UTT_IsEnum: 2892 return T->isEnumeralType(); 2893 case UTT_IsUnion: 2894 return T->isUnionType(); 2895 case UTT_IsClass: 2896 return T->isClassType() || T->isStructureType(); 2897 case UTT_IsFunction: 2898 return T->isFunctionType(); 2899 2900 // Type trait expressions which correspond to the convenient composition 2901 // predicates in C++0x [meta.unary.comp]. 2902 case UTT_IsReference: 2903 return T->isReferenceType(); 2904 case UTT_IsArithmetic: 2905 return T->isArithmeticType() && !T->isEnumeralType(); 2906 case UTT_IsFundamental: 2907 return T->isFundamentalType(); 2908 case UTT_IsObject: 2909 return T->isObjectType(); 2910 case UTT_IsScalar: 2911 // Note: semantic analysis depends on Objective-C lifetime types to be 2912 // considered scalar types. However, such types do not actually behave 2913 // like scalar types at run time (since they may require retain/release 2914 // operations), so we report them as non-scalar. 2915 if (T->isObjCLifetimeType()) { 2916 switch (T.getObjCLifetime()) { 2917 case Qualifiers::OCL_None: 2918 case Qualifiers::OCL_ExplicitNone: 2919 return true; 2920 2921 case Qualifiers::OCL_Strong: 2922 case Qualifiers::OCL_Weak: 2923 case Qualifiers::OCL_Autoreleasing: 2924 return false; 2925 } 2926 } 2927 2928 return T->isScalarType(); 2929 case UTT_IsCompound: 2930 return T->isCompoundType(); 2931 case UTT_IsMemberPointer: 2932 return T->isMemberPointerType(); 2933 2934 // Type trait expressions which correspond to the type property predicates 2935 // in C++0x [meta.unary.prop]. 2936 case UTT_IsConst: 2937 return T.isConstQualified(); 2938 case UTT_IsVolatile: 2939 return T.isVolatileQualified(); 2940 case UTT_IsTrivial: 2941 return T.isTrivialType(Self.Context); 2942 case UTT_IsTriviallyCopyable: 2943 return T.isTriviallyCopyableType(Self.Context); 2944 case UTT_IsStandardLayout: 2945 return T->isStandardLayoutType(); 2946 case UTT_IsPOD: 2947 return T.isPODType(Self.Context); 2948 case UTT_IsLiteral: 2949 return T->isLiteralType(); 2950 case UTT_IsEmpty: 2951 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 2952 return !RD->isUnion() && RD->isEmpty(); 2953 return false; 2954 case UTT_IsPolymorphic: 2955 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 2956 return RD->isPolymorphic(); 2957 return false; 2958 case UTT_IsAbstract: 2959 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 2960 return RD->isAbstract(); 2961 return false; 2962 case UTT_IsFinal: 2963 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 2964 return RD->hasAttr<FinalAttr>(); 2965 return false; 2966 case UTT_IsSigned: 2967 return T->isSignedIntegerType(); 2968 case UTT_IsUnsigned: 2969 return T->isUnsignedIntegerType(); 2970 2971 // Type trait expressions which query classes regarding their construction, 2972 // destruction, and copying. Rather than being based directly on the 2973 // related type predicates in the standard, they are specified by both 2974 // GCC[1] and the Embarcadero C++ compiler[2], and Clang implements those 2975 // specifications. 2976 // 2977 // 1: http://gcc.gnu/.org/onlinedocs/gcc/Type-Traits.html 2978 // 2: http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index 2979 case UTT_HasTrivialDefaultConstructor: 2980 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 2981 // If __is_pod (type) is true then the trait is true, else if type is 2982 // a cv class or union type (or array thereof) with a trivial default 2983 // constructor ([class.ctor]) then the trait is true, else it is false. 2984 if (T.isPODType(Self.Context)) 2985 return true; 2986 if (const RecordType *RT = 2987 C.getBaseElementType(T)->getAs<RecordType>()) 2988 return cast<CXXRecordDecl>(RT->getDecl())->hasTrivialDefaultConstructor(); 2989 return false; 2990 case UTT_HasTrivialCopy: 2991 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 2992 // If __is_pod (type) is true or type is a reference type then 2993 // the trait is true, else if type is a cv class or union type 2994 // with a trivial copy constructor ([class.copy]) then the trait 2995 // is true, else it is false. 2996 if (T.isPODType(Self.Context) || T->isReferenceType()) 2997 return true; 2998 if (const RecordType *RT = T->getAs<RecordType>()) 2999 return cast<CXXRecordDecl>(RT->getDecl())->hasTrivialCopyConstructor(); 3000 return false; 3001 case UTT_HasTrivialAssign: 3002 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3003 // If type is const qualified or is a reference type then the 3004 // trait is false. Otherwise if __is_pod (type) is true then the 3005 // trait is true, else if type is a cv class or union type with 3006 // a trivial copy assignment ([class.copy]) then the trait is 3007 // true, else it is false. 3008 // Note: the const and reference restrictions are interesting, 3009 // given that const and reference members don't prevent a class 3010 // from having a trivial copy assignment operator (but do cause 3011 // errors if the copy assignment operator is actually used, q.v. 3012 // [class.copy]p12). 3013 3014 if (C.getBaseElementType(T).isConstQualified()) 3015 return false; 3016 if (T.isPODType(Self.Context)) 3017 return true; 3018 if (const RecordType *RT = T->getAs<RecordType>()) 3019 return cast<CXXRecordDecl>(RT->getDecl())->hasTrivialCopyAssignment(); 3020 return false; 3021 case UTT_HasTrivialDestructor: 3022 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3023 // If __is_pod (type) is true or type is a reference type 3024 // then the trait is true, else if type is a cv class or union 3025 // type (or array thereof) with a trivial destructor 3026 // ([class.dtor]) then the trait is true, else it is 3027 // false. 3028 if (T.isPODType(Self.Context) || T->isReferenceType()) 3029 return true; 3030 3031 // Objective-C++ ARC: autorelease types don't require destruction. 3032 if (T->isObjCLifetimeType() && 3033 T.getObjCLifetime() == Qualifiers::OCL_Autoreleasing) 3034 return true; 3035 3036 if (const RecordType *RT = 3037 C.getBaseElementType(T)->getAs<RecordType>()) 3038 return cast<CXXRecordDecl>(RT->getDecl())->hasTrivialDestructor(); 3039 return false; 3040 // TODO: Propagate nothrowness for implicitly declared special members. 3041 case UTT_HasNothrowAssign: 3042 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3043 // If type is const qualified or is a reference type then the 3044 // trait is false. Otherwise if __has_trivial_assign (type) 3045 // is true then the trait is true, else if type is a cv class 3046 // or union type with copy assignment operators that are known 3047 // not to throw an exception then the trait is true, else it is 3048 // false. 3049 if (C.getBaseElementType(T).isConstQualified()) 3050 return false; 3051 if (T->isReferenceType()) 3052 return false; 3053 if (T.isPODType(Self.Context) || T->isObjCLifetimeType()) 3054 return true; 3055 if (const RecordType *RT = T->getAs<RecordType>()) { 3056 CXXRecordDecl* RD = cast<CXXRecordDecl>(RT->getDecl()); 3057 if (RD->hasTrivialCopyAssignment()) 3058 return true; 3059 3060 bool FoundAssign = false; 3061 DeclarationName Name = C.DeclarationNames.getCXXOperatorName(OO_Equal); 3062 LookupResult Res(Self, DeclarationNameInfo(Name, KeyLoc), 3063 Sema::LookupOrdinaryName); 3064 if (Self.LookupQualifiedName(Res, RD)) { 3065 Res.suppressDiagnostics(); 3066 for (LookupResult::iterator Op = Res.begin(), OpEnd = Res.end(); 3067 Op != OpEnd; ++Op) { 3068 if (isa<FunctionTemplateDecl>(*Op)) 3069 continue; 3070 3071 CXXMethodDecl *Operator = cast<CXXMethodDecl>(*Op); 3072 if (Operator->isCopyAssignmentOperator()) { 3073 FoundAssign = true; 3074 const FunctionProtoType *CPT 3075 = Operator->getType()->getAs<FunctionProtoType>(); 3076 if (CPT->getExceptionSpecType() == EST_Delayed) 3077 return false; 3078 if (!CPT->isNothrow(Self.Context)) 3079 return false; 3080 } 3081 } 3082 } 3083 3084 return FoundAssign; 3085 } 3086 return false; 3087 case UTT_HasNothrowCopy: 3088 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3089 // If __has_trivial_copy (type) is true then the trait is true, else 3090 // if type is a cv class or union type with copy constructors that are 3091 // known not to throw an exception then the trait is true, else it is 3092 // false. 3093 if (T.isPODType(C) || T->isReferenceType() || T->isObjCLifetimeType()) 3094 return true; 3095 if (const RecordType *RT = T->getAs<RecordType>()) { 3096 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 3097 if (RD->hasTrivialCopyConstructor()) 3098 return true; 3099 3100 bool FoundConstructor = false; 3101 unsigned FoundTQs; 3102 DeclContext::lookup_const_iterator Con, ConEnd; 3103 for (llvm::tie(Con, ConEnd) = Self.LookupConstructors(RD); 3104 Con != ConEnd; ++Con) { 3105 // A template constructor is never a copy constructor. 3106 // FIXME: However, it may actually be selected at the actual overload 3107 // resolution point. 3108 if (isa<FunctionTemplateDecl>(*Con)) 3109 continue; 3110 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con); 3111 if (Constructor->isCopyConstructor(FoundTQs)) { 3112 FoundConstructor = true; 3113 const FunctionProtoType *CPT 3114 = Constructor->getType()->getAs<FunctionProtoType>(); 3115 if (CPT->getExceptionSpecType() == EST_Delayed) 3116 return false; 3117 // FIXME: check whether evaluating default arguments can throw. 3118 // For now, we'll be conservative and assume that they can throw. 3119 if (!CPT->isNothrow(Self.Context) || CPT->getNumArgs() > 1) 3120 return false; 3121 } 3122 } 3123 3124 return FoundConstructor; 3125 } 3126 return false; 3127 case UTT_HasNothrowConstructor: 3128 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3129 // If __has_trivial_constructor (type) is true then the trait is 3130 // true, else if type is a cv class or union type (or array 3131 // thereof) with a default constructor that is known not to 3132 // throw an exception then the trait is true, else it is false. 3133 if (T.isPODType(C) || T->isObjCLifetimeType()) 3134 return true; 3135 if (const RecordType *RT = C.getBaseElementType(T)->getAs<RecordType>()) { 3136 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 3137 if (RD->hasTrivialDefaultConstructor()) 3138 return true; 3139 3140 DeclContext::lookup_const_iterator Con, ConEnd; 3141 for (llvm::tie(Con, ConEnd) = Self.LookupConstructors(RD); 3142 Con != ConEnd; ++Con) { 3143 // FIXME: In C++0x, a constructor template can be a default constructor. 3144 if (isa<FunctionTemplateDecl>(*Con)) 3145 continue; 3146 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con); 3147 if (Constructor->isDefaultConstructor()) { 3148 const FunctionProtoType *CPT 3149 = Constructor->getType()->getAs<FunctionProtoType>(); 3150 if (CPT->getExceptionSpecType() == EST_Delayed) 3151 return false; 3152 // TODO: check whether evaluating default arguments can throw. 3153 // For now, we'll be conservative and assume that they can throw. 3154 return CPT->isNothrow(Self.Context) && CPT->getNumArgs() == 0; 3155 } 3156 } 3157 } 3158 return false; 3159 case UTT_HasVirtualDestructor: 3160 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 3161 // If type is a class type with a virtual destructor ([class.dtor]) 3162 // then the trait is true, else it is false. 3163 if (const RecordType *Record = T->getAs<RecordType>()) { 3164 CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl()); 3165 if (CXXDestructorDecl *Destructor = Self.LookupDestructor(RD)) 3166 return Destructor->isVirtual(); 3167 } 3168 return false; 3169 3170 // These type trait expressions are modeled on the specifications for the 3171 // Embarcadero C++0x type trait functions: 3172 // http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index 3173 case UTT_IsCompleteType: 3174 // http://docwiki.embarcadero.com/RADStudio/XE/en/Is_complete_type_(typename_T_): 3175 // Returns True if and only if T is a complete type at the point of the 3176 // function call. 3177 return !T->isIncompleteType(); 3178 } 3179 llvm_unreachable("Type trait not covered by switch"); 3180} 3181 3182ExprResult Sema::BuildUnaryTypeTrait(UnaryTypeTrait UTT, 3183 SourceLocation KWLoc, 3184 TypeSourceInfo *TSInfo, 3185 SourceLocation RParen) { 3186 QualType T = TSInfo->getType(); 3187 if (!CheckUnaryTypeTraitTypeCompleteness(*this, UTT, KWLoc, T)) 3188 return ExprError(); 3189 3190 bool Value = false; 3191 if (!T->isDependentType()) 3192 Value = EvaluateUnaryTypeTrait(*this, UTT, KWLoc, T); 3193 3194 return Owned(new (Context) UnaryTypeTraitExpr(KWLoc, UTT, TSInfo, Value, 3195 RParen, Context.BoolTy)); 3196} 3197 3198ExprResult Sema::ActOnBinaryTypeTrait(BinaryTypeTrait BTT, 3199 SourceLocation KWLoc, 3200 ParsedType LhsTy, 3201 ParsedType RhsTy, 3202 SourceLocation RParen) { 3203 TypeSourceInfo *LhsTSInfo; 3204 QualType LhsT = GetTypeFromParser(LhsTy, &LhsTSInfo); 3205 if (!LhsTSInfo) 3206 LhsTSInfo = Context.getTrivialTypeSourceInfo(LhsT); 3207 3208 TypeSourceInfo *RhsTSInfo; 3209 QualType RhsT = GetTypeFromParser(RhsTy, &RhsTSInfo); 3210 if (!RhsTSInfo) 3211 RhsTSInfo = Context.getTrivialTypeSourceInfo(RhsT); 3212 3213 return BuildBinaryTypeTrait(BTT, KWLoc, LhsTSInfo, RhsTSInfo, RParen); 3214} 3215 3216static bool evaluateTypeTrait(Sema &S, TypeTrait Kind, SourceLocation KWLoc, 3217 ArrayRef<TypeSourceInfo *> Args, 3218 SourceLocation RParenLoc) { 3219 switch (Kind) { 3220 case clang::TT_IsTriviallyConstructible: { 3221 // C++11 [meta.unary.prop]: 3222 // is_trivially_constructible is defined as: 3223 // 3224 // is_constructible<T, Args...>::value is true and the variable 3225 // definition for is_constructible, as defined below, is known to call no 3226 // operation that is not trivial. 3227 // 3228 // The predicate condition for a template specialization 3229 // is_constructible<T, Args...> shall be satisfied if and only if the 3230 // following variable definition would be well-formed for some invented 3231 // variable t: 3232 // 3233 // T t(create<Args>()...); 3234 if (Args.empty()) { 3235 S.Diag(KWLoc, diag::err_type_trait_arity) 3236 << 1 << 1 << 1 << (int)Args.size(); 3237 return false; 3238 } 3239 3240 bool SawVoid = false; 3241 for (unsigned I = 0, N = Args.size(); I != N; ++I) { 3242 if (Args[I]->getType()->isVoidType()) { 3243 SawVoid = true; 3244 continue; 3245 } 3246 3247 if (!Args[I]->getType()->isIncompleteType() && 3248 S.RequireCompleteType(KWLoc, Args[I]->getType(), 3249 diag::err_incomplete_type_used_in_type_trait_expr)) 3250 return false; 3251 } 3252 3253 // If any argument was 'void', of course it won't type-check. 3254 if (SawVoid) 3255 return false; 3256 3257 llvm::SmallVector<OpaqueValueExpr, 2> OpaqueArgExprs; 3258 llvm::SmallVector<Expr *, 2> ArgExprs; 3259 ArgExprs.reserve(Args.size() - 1); 3260 for (unsigned I = 1, N = Args.size(); I != N; ++I) { 3261 QualType T = Args[I]->getType(); 3262 if (T->isObjectType() || T->isFunctionType()) 3263 T = S.Context.getRValueReferenceType(T); 3264 OpaqueArgExprs.push_back( 3265 OpaqueValueExpr(Args[I]->getTypeLoc().getSourceRange().getBegin(), 3266 T.getNonLValueExprType(S.Context), 3267 Expr::getValueKindForType(T))); 3268 ArgExprs.push_back(&OpaqueArgExprs.back()); 3269 } 3270 3271 // Perform the initialization in an unevaluated context within a SFINAE 3272 // trap at translation unit scope. 3273 EnterExpressionEvaluationContext Unevaluated(S, Sema::Unevaluated); 3274 Sema::SFINAETrap SFINAE(S, /*AccessCheckingSFINAE=*/true); 3275 Sema::ContextRAII TUContext(S, S.Context.getTranslationUnitDecl()); 3276 InitializedEntity To(InitializedEntity::InitializeTemporary(Args[0])); 3277 InitializationKind InitKind(InitializationKind::CreateDirect(KWLoc, KWLoc, 3278 RParenLoc)); 3279 InitializationSequence Init(S, To, InitKind, 3280 ArgExprs.begin(), ArgExprs.size()); 3281 if (Init.Failed()) 3282 return false; 3283 3284 ExprResult Result = Init.Perform(S, To, InitKind, 3285 MultiExprArg(ArgExprs.data(), 3286 ArgExprs.size())); 3287 if (Result.isInvalid() || SFINAE.hasErrorOccurred()) 3288 return false; 3289 3290 // The initialization succeeded; not make sure there are no non-trivial 3291 // calls. 3292 return !Result.get()->hasNonTrivialCall(S.Context); 3293 } 3294 } 3295 3296 return false; 3297} 3298 3299ExprResult Sema::BuildTypeTrait(TypeTrait Kind, SourceLocation KWLoc, 3300 ArrayRef<TypeSourceInfo *> Args, 3301 SourceLocation RParenLoc) { 3302 bool Dependent = false; 3303 for (unsigned I = 0, N = Args.size(); I != N; ++I) { 3304 if (Args[I]->getType()->isDependentType()) { 3305 Dependent = true; 3306 break; 3307 } 3308 } 3309 3310 bool Value = false; 3311 if (!Dependent) 3312 Value = evaluateTypeTrait(*this, Kind, KWLoc, Args, RParenLoc); 3313 3314 return TypeTraitExpr::Create(Context, Context.BoolTy, KWLoc, Kind, 3315 Args, RParenLoc, Value); 3316} 3317 3318ExprResult Sema::ActOnTypeTrait(TypeTrait Kind, SourceLocation KWLoc, 3319 ArrayRef<ParsedType> Args, 3320 SourceLocation RParenLoc) { 3321 llvm::SmallVector<TypeSourceInfo *, 4> ConvertedArgs; 3322 ConvertedArgs.reserve(Args.size()); 3323 3324 for (unsigned I = 0, N = Args.size(); I != N; ++I) { 3325 TypeSourceInfo *TInfo; 3326 QualType T = GetTypeFromParser(Args[I], &TInfo); 3327 if (!TInfo) 3328 TInfo = Context.getTrivialTypeSourceInfo(T, KWLoc); 3329 3330 ConvertedArgs.push_back(TInfo); 3331 } 3332 3333 return BuildTypeTrait(Kind, KWLoc, ConvertedArgs, RParenLoc); 3334} 3335 3336static bool EvaluateBinaryTypeTrait(Sema &Self, BinaryTypeTrait BTT, 3337 QualType LhsT, QualType RhsT, 3338 SourceLocation KeyLoc) { 3339 assert(!LhsT->isDependentType() && !RhsT->isDependentType() && 3340 "Cannot evaluate traits of dependent types"); 3341 3342 switch(BTT) { 3343 case BTT_IsBaseOf: { 3344 // C++0x [meta.rel]p2 3345 // Base is a base class of Derived without regard to cv-qualifiers or 3346 // Base and Derived are not unions and name the same class type without 3347 // regard to cv-qualifiers. 3348 3349 const RecordType *lhsRecord = LhsT->getAs<RecordType>(); 3350 if (!lhsRecord) return false; 3351 3352 const RecordType *rhsRecord = RhsT->getAs<RecordType>(); 3353 if (!rhsRecord) return false; 3354 3355 assert(Self.Context.hasSameUnqualifiedType(LhsT, RhsT) 3356 == (lhsRecord == rhsRecord)); 3357 3358 if (lhsRecord == rhsRecord) 3359 return !lhsRecord->getDecl()->isUnion(); 3360 3361 // C++0x [meta.rel]p2: 3362 // If Base and Derived are class types and are different types 3363 // (ignoring possible cv-qualifiers) then Derived shall be a 3364 // complete type. 3365 if (Self.RequireCompleteType(KeyLoc, RhsT, 3366 diag::err_incomplete_type_used_in_type_trait_expr)) 3367 return false; 3368 3369 return cast<CXXRecordDecl>(rhsRecord->getDecl()) 3370 ->isDerivedFrom(cast<CXXRecordDecl>(lhsRecord->getDecl())); 3371 } 3372 case BTT_IsSame: 3373 return Self.Context.hasSameType(LhsT, RhsT); 3374 case BTT_TypeCompatible: 3375 return Self.Context.typesAreCompatible(LhsT.getUnqualifiedType(), 3376 RhsT.getUnqualifiedType()); 3377 case BTT_IsConvertible: 3378 case BTT_IsConvertibleTo: { 3379 // C++0x [meta.rel]p4: 3380 // Given the following function prototype: 3381 // 3382 // template <class T> 3383 // typename add_rvalue_reference<T>::type create(); 3384 // 3385 // the predicate condition for a template specialization 3386 // is_convertible<From, To> shall be satisfied if and only if 3387 // the return expression in the following code would be 3388 // well-formed, including any implicit conversions to the return 3389 // type of the function: 3390 // 3391 // To test() { 3392 // return create<From>(); 3393 // } 3394 // 3395 // Access checking is performed as if in a context unrelated to To and 3396 // From. Only the validity of the immediate context of the expression 3397 // of the return-statement (including conversions to the return type) 3398 // is considered. 3399 // 3400 // We model the initialization as a copy-initialization of a temporary 3401 // of the appropriate type, which for this expression is identical to the 3402 // return statement (since NRVO doesn't apply). 3403 if (LhsT->isObjectType() || LhsT->isFunctionType()) 3404 LhsT = Self.Context.getRValueReferenceType(LhsT); 3405 3406 InitializedEntity To(InitializedEntity::InitializeTemporary(RhsT)); 3407 OpaqueValueExpr From(KeyLoc, LhsT.getNonLValueExprType(Self.Context), 3408 Expr::getValueKindForType(LhsT)); 3409 Expr *FromPtr = &From; 3410 InitializationKind Kind(InitializationKind::CreateCopy(KeyLoc, 3411 SourceLocation())); 3412 3413 // Perform the initialization in an unevaluated context within a SFINAE 3414 // trap at translation unit scope. 3415 EnterExpressionEvaluationContext Unevaluated(Self, Sema::Unevaluated); 3416 Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true); 3417 Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl()); 3418 InitializationSequence Init(Self, To, Kind, &FromPtr, 1); 3419 if (Init.Failed()) 3420 return false; 3421 3422 ExprResult Result = Init.Perform(Self, To, Kind, MultiExprArg(&FromPtr, 1)); 3423 return !Result.isInvalid() && !SFINAE.hasErrorOccurred(); 3424 } 3425 3426 case BTT_IsTriviallyAssignable: { 3427 // C++11 [meta.unary.prop]p3: 3428 // is_trivially_assignable is defined as: 3429 // is_assignable<T, U>::value is true and the assignment, as defined by 3430 // is_assignable, is known to call no operation that is not trivial 3431 // 3432 // is_assignable is defined as: 3433 // The expression declval<T>() = declval<U>() is well-formed when 3434 // treated as an unevaluated operand (Clause 5). 3435 // 3436 // For both, T and U shall be complete types, (possibly cv-qualified) 3437 // void, or arrays of unknown bound. 3438 if (!LhsT->isVoidType() && !LhsT->isIncompleteArrayType() && 3439 Self.RequireCompleteType(KeyLoc, LhsT, 3440 diag::err_incomplete_type_used_in_type_trait_expr)) 3441 return false; 3442 if (!RhsT->isVoidType() && !RhsT->isIncompleteArrayType() && 3443 Self.RequireCompleteType(KeyLoc, RhsT, 3444 diag::err_incomplete_type_used_in_type_trait_expr)) 3445 return false; 3446 3447 // cv void is never assignable. 3448 if (LhsT->isVoidType() || RhsT->isVoidType()) 3449 return false; 3450 3451 // Build expressions that emulate the effect of declval<T>() and 3452 // declval<U>(). 3453 if (LhsT->isObjectType() || LhsT->isFunctionType()) 3454 LhsT = Self.Context.getRValueReferenceType(LhsT); 3455 if (RhsT->isObjectType() || RhsT->isFunctionType()) 3456 RhsT = Self.Context.getRValueReferenceType(RhsT); 3457 OpaqueValueExpr Lhs(KeyLoc, LhsT.getNonLValueExprType(Self.Context), 3458 Expr::getValueKindForType(LhsT)); 3459 OpaqueValueExpr Rhs(KeyLoc, RhsT.getNonLValueExprType(Self.Context), 3460 Expr::getValueKindForType(RhsT)); 3461 3462 // Attempt the assignment in an unevaluated context within a SFINAE 3463 // trap at translation unit scope. 3464 EnterExpressionEvaluationContext Unevaluated(Self, Sema::Unevaluated); 3465 Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true); 3466 Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl()); 3467 ExprResult Result = Self.BuildBinOp(/*S=*/0, KeyLoc, BO_Assign, &Lhs, &Rhs); 3468 if (Result.isInvalid() || SFINAE.hasErrorOccurred()) 3469 return false; 3470 3471 return !Result.get()->hasNonTrivialCall(Self.Context); 3472 } 3473 } 3474 llvm_unreachable("Unknown type trait or not implemented"); 3475} 3476 3477ExprResult Sema::BuildBinaryTypeTrait(BinaryTypeTrait BTT, 3478 SourceLocation KWLoc, 3479 TypeSourceInfo *LhsTSInfo, 3480 TypeSourceInfo *RhsTSInfo, 3481 SourceLocation RParen) { 3482 QualType LhsT = LhsTSInfo->getType(); 3483 QualType RhsT = RhsTSInfo->getType(); 3484 3485 if (BTT == BTT_TypeCompatible) { 3486 if (getLangOptions().CPlusPlus) { 3487 Diag(KWLoc, diag::err_types_compatible_p_in_cplusplus) 3488 << SourceRange(KWLoc, RParen); 3489 return ExprError(); 3490 } 3491 } 3492 3493 bool Value = false; 3494 if (!LhsT->isDependentType() && !RhsT->isDependentType()) 3495 Value = EvaluateBinaryTypeTrait(*this, BTT, LhsT, RhsT, KWLoc); 3496 3497 // Select trait result type. 3498 QualType ResultType; 3499 switch (BTT) { 3500 case BTT_IsBaseOf: ResultType = Context.BoolTy; break; 3501 case BTT_IsConvertible: ResultType = Context.BoolTy; break; 3502 case BTT_IsSame: ResultType = Context.BoolTy; break; 3503 case BTT_TypeCompatible: ResultType = Context.IntTy; break; 3504 case BTT_IsConvertibleTo: ResultType = Context.BoolTy; break; 3505 case BTT_IsTriviallyAssignable: ResultType = Context.BoolTy; 3506 } 3507 3508 return Owned(new (Context) BinaryTypeTraitExpr(KWLoc, BTT, LhsTSInfo, 3509 RhsTSInfo, Value, RParen, 3510 ResultType)); 3511} 3512 3513ExprResult Sema::ActOnArrayTypeTrait(ArrayTypeTrait ATT, 3514 SourceLocation KWLoc, 3515 ParsedType Ty, 3516 Expr* DimExpr, 3517 SourceLocation RParen) { 3518 TypeSourceInfo *TSInfo; 3519 QualType T = GetTypeFromParser(Ty, &TSInfo); 3520 if (!TSInfo) 3521 TSInfo = Context.getTrivialTypeSourceInfo(T); 3522 3523 return BuildArrayTypeTrait(ATT, KWLoc, TSInfo, DimExpr, RParen); 3524} 3525 3526static uint64_t EvaluateArrayTypeTrait(Sema &Self, ArrayTypeTrait ATT, 3527 QualType T, Expr *DimExpr, 3528 SourceLocation KeyLoc) { 3529 assert(!T->isDependentType() && "Cannot evaluate traits of dependent type"); 3530 3531 switch(ATT) { 3532 case ATT_ArrayRank: 3533 if (T->isArrayType()) { 3534 unsigned Dim = 0; 3535 while (const ArrayType *AT = Self.Context.getAsArrayType(T)) { 3536 ++Dim; 3537 T = AT->getElementType(); 3538 } 3539 return Dim; 3540 } 3541 return 0; 3542 3543 case ATT_ArrayExtent: { 3544 llvm::APSInt Value; 3545 uint64_t Dim; 3546 if (Self.VerifyIntegerConstantExpression(DimExpr, &Value, 3547 Self.PDiag(diag::err_dimension_expr_not_constant_integer), 3548 false).isInvalid()) 3549 return 0; 3550 if (Value.isSigned() && Value.isNegative()) { 3551 Self.Diag(KeyLoc, diag::err_dimension_expr_not_constant_integer), 3552 DimExpr->getSourceRange(); 3553 return 0; 3554 } 3555 Dim = Value.getLimitedValue(); 3556 3557 if (T->isArrayType()) { 3558 unsigned D = 0; 3559 bool Matched = false; 3560 while (const ArrayType *AT = Self.Context.getAsArrayType(T)) { 3561 if (Dim == D) { 3562 Matched = true; 3563 break; 3564 } 3565 ++D; 3566 T = AT->getElementType(); 3567 } 3568 3569 if (Matched && T->isArrayType()) { 3570 if (const ConstantArrayType *CAT = Self.Context.getAsConstantArrayType(T)) 3571 return CAT->getSize().getLimitedValue(); 3572 } 3573 } 3574 return 0; 3575 } 3576 } 3577 llvm_unreachable("Unknown type trait or not implemented"); 3578} 3579 3580ExprResult Sema::BuildArrayTypeTrait(ArrayTypeTrait ATT, 3581 SourceLocation KWLoc, 3582 TypeSourceInfo *TSInfo, 3583 Expr* DimExpr, 3584 SourceLocation RParen) { 3585 QualType T = TSInfo->getType(); 3586 3587 // FIXME: This should likely be tracked as an APInt to remove any host 3588 // assumptions about the width of size_t on the target. 3589 uint64_t Value = 0; 3590 if (!T->isDependentType()) 3591 Value = EvaluateArrayTypeTrait(*this, ATT, T, DimExpr, KWLoc); 3592 3593 // While the specification for these traits from the Embarcadero C++ 3594 // compiler's documentation says the return type is 'unsigned int', Clang 3595 // returns 'size_t'. On Windows, the primary platform for the Embarcadero 3596 // compiler, there is no difference. On several other platforms this is an 3597 // important distinction. 3598 return Owned(new (Context) ArrayTypeTraitExpr(KWLoc, ATT, TSInfo, Value, 3599 DimExpr, RParen, 3600 Context.getSizeType())); 3601} 3602 3603ExprResult Sema::ActOnExpressionTrait(ExpressionTrait ET, 3604 SourceLocation KWLoc, 3605 Expr *Queried, 3606 SourceLocation RParen) { 3607 // If error parsing the expression, ignore. 3608 if (!Queried) 3609 return ExprError(); 3610 3611 ExprResult Result = BuildExpressionTrait(ET, KWLoc, Queried, RParen); 3612 3613 return move(Result); 3614} 3615 3616static bool EvaluateExpressionTrait(ExpressionTrait ET, Expr *E) { 3617 switch (ET) { 3618 case ET_IsLValueExpr: return E->isLValue(); 3619 case ET_IsRValueExpr: return E->isRValue(); 3620 } 3621 llvm_unreachable("Expression trait not covered by switch"); 3622} 3623 3624ExprResult Sema::BuildExpressionTrait(ExpressionTrait ET, 3625 SourceLocation KWLoc, 3626 Expr *Queried, 3627 SourceLocation RParen) { 3628 if (Queried->isTypeDependent()) { 3629 // Delay type-checking for type-dependent expressions. 3630 } else if (Queried->getType()->isPlaceholderType()) { 3631 ExprResult PE = CheckPlaceholderExpr(Queried); 3632 if (PE.isInvalid()) return ExprError(); 3633 return BuildExpressionTrait(ET, KWLoc, PE.take(), RParen); 3634 } 3635 3636 bool Value = EvaluateExpressionTrait(ET, Queried); 3637 3638 return Owned(new (Context) ExpressionTraitExpr(KWLoc, ET, Queried, Value, 3639 RParen, Context.BoolTy)); 3640} 3641 3642QualType Sema::CheckPointerToMemberOperands(ExprResult &LHS, ExprResult &RHS, 3643 ExprValueKind &VK, 3644 SourceLocation Loc, 3645 bool isIndirect) { 3646 assert(!LHS.get()->getType()->isPlaceholderType() && 3647 !RHS.get()->getType()->isPlaceholderType() && 3648 "placeholders should have been weeded out by now"); 3649 3650 // The LHS undergoes lvalue conversions if this is ->*. 3651 if (isIndirect) { 3652 LHS = DefaultLvalueConversion(LHS.take()); 3653 if (LHS.isInvalid()) return QualType(); 3654 } 3655 3656 // The RHS always undergoes lvalue conversions. 3657 RHS = DefaultLvalueConversion(RHS.take()); 3658 if (RHS.isInvalid()) return QualType(); 3659 3660 const char *OpSpelling = isIndirect ? "->*" : ".*"; 3661 // C++ 5.5p2 3662 // The binary operator .* [p3: ->*] binds its second operand, which shall 3663 // be of type "pointer to member of T" (where T is a completely-defined 3664 // class type) [...] 3665 QualType RHSType = RHS.get()->getType(); 3666 const MemberPointerType *MemPtr = RHSType->getAs<MemberPointerType>(); 3667 if (!MemPtr) { 3668 Diag(Loc, diag::err_bad_memptr_rhs) 3669 << OpSpelling << RHSType << RHS.get()->getSourceRange(); 3670 return QualType(); 3671 } 3672 3673 QualType Class(MemPtr->getClass(), 0); 3674 3675 // Note: C++ [expr.mptr.oper]p2-3 says that the class type into which the 3676 // member pointer points must be completely-defined. However, there is no 3677 // reason for this semantic distinction, and the rule is not enforced by 3678 // other compilers. Therefore, we do not check this property, as it is 3679 // likely to be considered a defect. 3680 3681 // C++ 5.5p2 3682 // [...] to its first operand, which shall be of class T or of a class of 3683 // which T is an unambiguous and accessible base class. [p3: a pointer to 3684 // such a class] 3685 QualType LHSType = LHS.get()->getType(); 3686 if (isIndirect) { 3687 if (const PointerType *Ptr = LHSType->getAs<PointerType>()) 3688 LHSType = Ptr->getPointeeType(); 3689 else { 3690 Diag(Loc, diag::err_bad_memptr_lhs) 3691 << OpSpelling << 1 << LHSType 3692 << FixItHint::CreateReplacement(SourceRange(Loc), ".*"); 3693 return QualType(); 3694 } 3695 } 3696 3697 if (!Context.hasSameUnqualifiedType(Class, LHSType)) { 3698 // If we want to check the hierarchy, we need a complete type. 3699 if (RequireCompleteType(Loc, LHSType, PDiag(diag::err_bad_memptr_lhs) 3700 << OpSpelling << (int)isIndirect)) { 3701 return QualType(); 3702 } 3703 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 3704 /*DetectVirtual=*/false); 3705 // FIXME: Would it be useful to print full ambiguity paths, or is that 3706 // overkill? 3707 if (!IsDerivedFrom(LHSType, Class, Paths) || 3708 Paths.isAmbiguous(Context.getCanonicalType(Class))) { 3709 Diag(Loc, diag::err_bad_memptr_lhs) << OpSpelling 3710 << (int)isIndirect << LHS.get()->getType(); 3711 return QualType(); 3712 } 3713 // Cast LHS to type of use. 3714 QualType UseType = isIndirect ? Context.getPointerType(Class) : Class; 3715 ExprValueKind VK = isIndirect ? VK_RValue : LHS.get()->getValueKind(); 3716 3717 CXXCastPath BasePath; 3718 BuildBasePathArray(Paths, BasePath); 3719 LHS = ImpCastExprToType(LHS.take(), UseType, CK_DerivedToBase, VK, 3720 &BasePath); 3721 } 3722 3723 if (isa<CXXScalarValueInitExpr>(RHS.get()->IgnoreParens())) { 3724 // Diagnose use of pointer-to-member type which when used as 3725 // the functional cast in a pointer-to-member expression. 3726 Diag(Loc, diag::err_pointer_to_member_type) << isIndirect; 3727 return QualType(); 3728 } 3729 3730 // C++ 5.5p2 3731 // The result is an object or a function of the type specified by the 3732 // second operand. 3733 // The cv qualifiers are the union of those in the pointer and the left side, 3734 // in accordance with 5.5p5 and 5.2.5. 3735 QualType Result = MemPtr->getPointeeType(); 3736 Result = Context.getCVRQualifiedType(Result, LHSType.getCVRQualifiers()); 3737 3738 // C++0x [expr.mptr.oper]p6: 3739 // In a .* expression whose object expression is an rvalue, the program is 3740 // ill-formed if the second operand is a pointer to member function with 3741 // ref-qualifier &. In a ->* expression or in a .* expression whose object 3742 // expression is an lvalue, the program is ill-formed if the second operand 3743 // is a pointer to member function with ref-qualifier &&. 3744 if (const FunctionProtoType *Proto = Result->getAs<FunctionProtoType>()) { 3745 switch (Proto->getRefQualifier()) { 3746 case RQ_None: 3747 // Do nothing 3748 break; 3749 3750 case RQ_LValue: 3751 if (!isIndirect && !LHS.get()->Classify(Context).isLValue()) 3752 Diag(Loc, diag::err_pointer_to_member_oper_value_classify) 3753 << RHSType << 1 << LHS.get()->getSourceRange(); 3754 break; 3755 3756 case RQ_RValue: 3757 if (isIndirect || !LHS.get()->Classify(Context).isRValue()) 3758 Diag(Loc, diag::err_pointer_to_member_oper_value_classify) 3759 << RHSType << 0 << LHS.get()->getSourceRange(); 3760 break; 3761 } 3762 } 3763 3764 // C++ [expr.mptr.oper]p6: 3765 // The result of a .* expression whose second operand is a pointer 3766 // to a data member is of the same value category as its 3767 // first operand. The result of a .* expression whose second 3768 // operand is a pointer to a member function is a prvalue. The 3769 // result of an ->* expression is an lvalue if its second operand 3770 // is a pointer to data member and a prvalue otherwise. 3771 if (Result->isFunctionType()) { 3772 VK = VK_RValue; 3773 return Context.BoundMemberTy; 3774 } else if (isIndirect) { 3775 VK = VK_LValue; 3776 } else { 3777 VK = LHS.get()->getValueKind(); 3778 } 3779 3780 return Result; 3781} 3782 3783/// \brief Try to convert a type to another according to C++0x 5.16p3. 3784/// 3785/// This is part of the parameter validation for the ? operator. If either 3786/// value operand is a class type, the two operands are attempted to be 3787/// converted to each other. This function does the conversion in one direction. 3788/// It returns true if the program is ill-formed and has already been diagnosed 3789/// as such. 3790static bool TryClassUnification(Sema &Self, Expr *From, Expr *To, 3791 SourceLocation QuestionLoc, 3792 bool &HaveConversion, 3793 QualType &ToType) { 3794 HaveConversion = false; 3795 ToType = To->getType(); 3796 3797 InitializationKind Kind = InitializationKind::CreateCopy(To->getLocStart(), 3798 SourceLocation()); 3799 // C++0x 5.16p3 3800 // The process for determining whether an operand expression E1 of type T1 3801 // can be converted to match an operand expression E2 of type T2 is defined 3802 // as follows: 3803 // -- If E2 is an lvalue: 3804 bool ToIsLvalue = To->isLValue(); 3805 if (ToIsLvalue) { 3806 // E1 can be converted to match E2 if E1 can be implicitly converted to 3807 // type "lvalue reference to T2", subject to the constraint that in the 3808 // conversion the reference must bind directly to E1. 3809 QualType T = Self.Context.getLValueReferenceType(ToType); 3810 InitializedEntity Entity = InitializedEntity::InitializeTemporary(T); 3811 3812 InitializationSequence InitSeq(Self, Entity, Kind, &From, 1); 3813 if (InitSeq.isDirectReferenceBinding()) { 3814 ToType = T; 3815 HaveConversion = true; 3816 return false; 3817 } 3818 3819 if (InitSeq.isAmbiguous()) 3820 return InitSeq.Diagnose(Self, Entity, Kind, &From, 1); 3821 } 3822 3823 // -- If E2 is an rvalue, or if the conversion above cannot be done: 3824 // -- if E1 and E2 have class type, and the underlying class types are 3825 // the same or one is a base class of the other: 3826 QualType FTy = From->getType(); 3827 QualType TTy = To->getType(); 3828 const RecordType *FRec = FTy->getAs<RecordType>(); 3829 const RecordType *TRec = TTy->getAs<RecordType>(); 3830 bool FDerivedFromT = FRec && TRec && FRec != TRec && 3831 Self.IsDerivedFrom(FTy, TTy); 3832 if (FRec && TRec && 3833 (FRec == TRec || FDerivedFromT || Self.IsDerivedFrom(TTy, FTy))) { 3834 // E1 can be converted to match E2 if the class of T2 is the 3835 // same type as, or a base class of, the class of T1, and 3836 // [cv2 > cv1]. 3837 if (FRec == TRec || FDerivedFromT) { 3838 if (TTy.isAtLeastAsQualifiedAs(FTy)) { 3839 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy); 3840 InitializationSequence InitSeq(Self, Entity, Kind, &From, 1); 3841 if (InitSeq) { 3842 HaveConversion = true; 3843 return false; 3844 } 3845 3846 if (InitSeq.isAmbiguous()) 3847 return InitSeq.Diagnose(Self, Entity, Kind, &From, 1); 3848 } 3849 } 3850 3851 return false; 3852 } 3853 3854 // -- Otherwise: E1 can be converted to match E2 if E1 can be 3855 // implicitly converted to the type that expression E2 would have 3856 // if E2 were converted to an rvalue (or the type it has, if E2 is 3857 // an rvalue). 3858 // 3859 // This actually refers very narrowly to the lvalue-to-rvalue conversion, not 3860 // to the array-to-pointer or function-to-pointer conversions. 3861 if (!TTy->getAs<TagType>()) 3862 TTy = TTy.getUnqualifiedType(); 3863 3864 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy); 3865 InitializationSequence InitSeq(Self, Entity, Kind, &From, 1); 3866 HaveConversion = !InitSeq.Failed(); 3867 ToType = TTy; 3868 if (InitSeq.isAmbiguous()) 3869 return InitSeq.Diagnose(Self, Entity, Kind, &From, 1); 3870 3871 return false; 3872} 3873 3874/// \brief Try to find a common type for two according to C++0x 5.16p5. 3875/// 3876/// This is part of the parameter validation for the ? operator. If either 3877/// value operand is a class type, overload resolution is used to find a 3878/// conversion to a common type. 3879static bool FindConditionalOverload(Sema &Self, ExprResult &LHS, ExprResult &RHS, 3880 SourceLocation QuestionLoc) { 3881 Expr *Args[2] = { LHS.get(), RHS.get() }; 3882 OverloadCandidateSet CandidateSet(QuestionLoc); 3883 Self.AddBuiltinOperatorCandidates(OO_Conditional, QuestionLoc, Args, 2, 3884 CandidateSet); 3885 3886 OverloadCandidateSet::iterator Best; 3887 switch (CandidateSet.BestViableFunction(Self, QuestionLoc, Best)) { 3888 case OR_Success: { 3889 // We found a match. Perform the conversions on the arguments and move on. 3890 ExprResult LHSRes = 3891 Self.PerformImplicitConversion(LHS.get(), Best->BuiltinTypes.ParamTypes[0], 3892 Best->Conversions[0], Sema::AA_Converting); 3893 if (LHSRes.isInvalid()) 3894 break; 3895 LHS = move(LHSRes); 3896 3897 ExprResult RHSRes = 3898 Self.PerformImplicitConversion(RHS.get(), Best->BuiltinTypes.ParamTypes[1], 3899 Best->Conversions[1], Sema::AA_Converting); 3900 if (RHSRes.isInvalid()) 3901 break; 3902 RHS = move(RHSRes); 3903 if (Best->Function) 3904 Self.MarkFunctionReferenced(QuestionLoc, Best->Function); 3905 return false; 3906 } 3907 3908 case OR_No_Viable_Function: 3909 3910 // Emit a better diagnostic if one of the expressions is a null pointer 3911 // constant and the other is a pointer type. In this case, the user most 3912 // likely forgot to take the address of the other expression. 3913 if (Self.DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc)) 3914 return true; 3915 3916 Self.Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 3917 << LHS.get()->getType() << RHS.get()->getType() 3918 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 3919 return true; 3920 3921 case OR_Ambiguous: 3922 Self.Diag(QuestionLoc, diag::err_conditional_ambiguous_ovl) 3923 << LHS.get()->getType() << RHS.get()->getType() 3924 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 3925 // FIXME: Print the possible common types by printing the return types of 3926 // the viable candidates. 3927 break; 3928 3929 case OR_Deleted: 3930 llvm_unreachable("Conditional operator has only built-in overloads"); 3931 } 3932 return true; 3933} 3934 3935/// \brief Perform an "extended" implicit conversion as returned by 3936/// TryClassUnification. 3937static bool ConvertForConditional(Sema &Self, ExprResult &E, QualType T) { 3938 InitializedEntity Entity = InitializedEntity::InitializeTemporary(T); 3939 InitializationKind Kind = InitializationKind::CreateCopy(E.get()->getLocStart(), 3940 SourceLocation()); 3941 Expr *Arg = E.take(); 3942 InitializationSequence InitSeq(Self, Entity, Kind, &Arg, 1); 3943 ExprResult Result = InitSeq.Perform(Self, Entity, Kind, MultiExprArg(&Arg, 1)); 3944 if (Result.isInvalid()) 3945 return true; 3946 3947 E = Result; 3948 return false; 3949} 3950 3951/// \brief Check the operands of ?: under C++ semantics. 3952/// 3953/// See C++ [expr.cond]. Note that LHS is never null, even for the GNU x ?: y 3954/// extension. In this case, LHS == Cond. (But they're not aliases.) 3955QualType Sema::CXXCheckConditionalOperands(ExprResult &Cond, ExprResult &LHS, ExprResult &RHS, 3956 ExprValueKind &VK, ExprObjectKind &OK, 3957 SourceLocation QuestionLoc) { 3958 // FIXME: Handle C99's complex types, vector types, block pointers and Obj-C++ 3959 // interface pointers. 3960 3961 // C++0x 5.16p1 3962 // The first expression is contextually converted to bool. 3963 if (!Cond.get()->isTypeDependent()) { 3964 ExprResult CondRes = CheckCXXBooleanCondition(Cond.take()); 3965 if (CondRes.isInvalid()) 3966 return QualType(); 3967 Cond = move(CondRes); 3968 } 3969 3970 // Assume r-value. 3971 VK = VK_RValue; 3972 OK = OK_Ordinary; 3973 3974 // Either of the arguments dependent? 3975 if (LHS.get()->isTypeDependent() || RHS.get()->isTypeDependent()) 3976 return Context.DependentTy; 3977 3978 // C++0x 5.16p2 3979 // If either the second or the third operand has type (cv) void, ... 3980 QualType LTy = LHS.get()->getType(); 3981 QualType RTy = RHS.get()->getType(); 3982 bool LVoid = LTy->isVoidType(); 3983 bool RVoid = RTy->isVoidType(); 3984 if (LVoid || RVoid) { 3985 // ... then the [l2r] conversions are performed on the second and third 3986 // operands ... 3987 LHS = DefaultFunctionArrayLvalueConversion(LHS.take()); 3988 RHS = DefaultFunctionArrayLvalueConversion(RHS.take()); 3989 if (LHS.isInvalid() || RHS.isInvalid()) 3990 return QualType(); 3991 LTy = LHS.get()->getType(); 3992 RTy = RHS.get()->getType(); 3993 3994 // ... and one of the following shall hold: 3995 // -- The second or the third operand (but not both) is a throw- 3996 // expression; the result is of the type of the other and is an rvalue. 3997 bool LThrow = isa<CXXThrowExpr>(LHS.get()); 3998 bool RThrow = isa<CXXThrowExpr>(RHS.get()); 3999 if (LThrow && !RThrow) 4000 return RTy; 4001 if (RThrow && !LThrow) 4002 return LTy; 4003 4004 // -- Both the second and third operands have type void; the result is of 4005 // type void and is an rvalue. 4006 if (LVoid && RVoid) 4007 return Context.VoidTy; 4008 4009 // Neither holds, error. 4010 Diag(QuestionLoc, diag::err_conditional_void_nonvoid) 4011 << (LVoid ? RTy : LTy) << (LVoid ? 0 : 1) 4012 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 4013 return QualType(); 4014 } 4015 4016 // Neither is void. 4017 4018 // C++0x 5.16p3 4019 // Otherwise, if the second and third operand have different types, and 4020 // either has (cv) class type, and attempt is made to convert each of those 4021 // operands to the other. 4022 if (!Context.hasSameType(LTy, RTy) && 4023 (LTy->isRecordType() || RTy->isRecordType())) { 4024 ImplicitConversionSequence ICSLeftToRight, ICSRightToLeft; 4025 // These return true if a single direction is already ambiguous. 4026 QualType L2RType, R2LType; 4027 bool HaveL2R, HaveR2L; 4028 if (TryClassUnification(*this, LHS.get(), RHS.get(), QuestionLoc, HaveL2R, L2RType)) 4029 return QualType(); 4030 if (TryClassUnification(*this, RHS.get(), LHS.get(), QuestionLoc, HaveR2L, R2LType)) 4031 return QualType(); 4032 4033 // If both can be converted, [...] the program is ill-formed. 4034 if (HaveL2R && HaveR2L) { 4035 Diag(QuestionLoc, diag::err_conditional_ambiguous) 4036 << LTy << RTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 4037 return QualType(); 4038 } 4039 4040 // If exactly one conversion is possible, that conversion is applied to 4041 // the chosen operand and the converted operands are used in place of the 4042 // original operands for the remainder of this section. 4043 if (HaveL2R) { 4044 if (ConvertForConditional(*this, LHS, L2RType) || LHS.isInvalid()) 4045 return QualType(); 4046 LTy = LHS.get()->getType(); 4047 } else if (HaveR2L) { 4048 if (ConvertForConditional(*this, RHS, R2LType) || RHS.isInvalid()) 4049 return QualType(); 4050 RTy = RHS.get()->getType(); 4051 } 4052 } 4053 4054 // C++0x 5.16p4 4055 // If the second and third operands are glvalues of the same value 4056 // category and have the same type, the result is of that type and 4057 // value category and it is a bit-field if the second or the third 4058 // operand is a bit-field, or if both are bit-fields. 4059 // We only extend this to bitfields, not to the crazy other kinds of 4060 // l-values. 4061 bool Same = Context.hasSameType(LTy, RTy); 4062 if (Same && 4063 LHS.get()->isGLValue() && 4064 LHS.get()->getValueKind() == RHS.get()->getValueKind() && 4065 LHS.get()->isOrdinaryOrBitFieldObject() && 4066 RHS.get()->isOrdinaryOrBitFieldObject()) { 4067 VK = LHS.get()->getValueKind(); 4068 if (LHS.get()->getObjectKind() == OK_BitField || 4069 RHS.get()->getObjectKind() == OK_BitField) 4070 OK = OK_BitField; 4071 return LTy; 4072 } 4073 4074 // C++0x 5.16p5 4075 // Otherwise, the result is an rvalue. If the second and third operands 4076 // do not have the same type, and either has (cv) class type, ... 4077 if (!Same && (LTy->isRecordType() || RTy->isRecordType())) { 4078 // ... overload resolution is used to determine the conversions (if any) 4079 // to be applied to the operands. If the overload resolution fails, the 4080 // program is ill-formed. 4081 if (FindConditionalOverload(*this, LHS, RHS, QuestionLoc)) 4082 return QualType(); 4083 } 4084 4085 // C++0x 5.16p6 4086 // LValue-to-rvalue, array-to-pointer, and function-to-pointer standard 4087 // conversions are performed on the second and third operands. 4088 LHS = DefaultFunctionArrayLvalueConversion(LHS.take()); 4089 RHS = DefaultFunctionArrayLvalueConversion(RHS.take()); 4090 if (LHS.isInvalid() || RHS.isInvalid()) 4091 return QualType(); 4092 LTy = LHS.get()->getType(); 4093 RTy = RHS.get()->getType(); 4094 4095 // After those conversions, one of the following shall hold: 4096 // -- The second and third operands have the same type; the result 4097 // is of that type. If the operands have class type, the result 4098 // is a prvalue temporary of the result type, which is 4099 // copy-initialized from either the second operand or the third 4100 // operand depending on the value of the first operand. 4101 if (Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy)) { 4102 if (LTy->isRecordType()) { 4103 // The operands have class type. Make a temporary copy. 4104 InitializedEntity Entity = InitializedEntity::InitializeTemporary(LTy); 4105 ExprResult LHSCopy = PerformCopyInitialization(Entity, 4106 SourceLocation(), 4107 LHS); 4108 if (LHSCopy.isInvalid()) 4109 return QualType(); 4110 4111 ExprResult RHSCopy = PerformCopyInitialization(Entity, 4112 SourceLocation(), 4113 RHS); 4114 if (RHSCopy.isInvalid()) 4115 return QualType(); 4116 4117 LHS = LHSCopy; 4118 RHS = RHSCopy; 4119 } 4120 4121 return LTy; 4122 } 4123 4124 // Extension: conditional operator involving vector types. 4125 if (LTy->isVectorType() || RTy->isVectorType()) 4126 return CheckVectorOperands(LHS, RHS, QuestionLoc, /*isCompAssign*/false); 4127 4128 // -- The second and third operands have arithmetic or enumeration type; 4129 // the usual arithmetic conversions are performed to bring them to a 4130 // common type, and the result is of that type. 4131 if (LTy->isArithmeticType() && RTy->isArithmeticType()) { 4132 UsualArithmeticConversions(LHS, RHS); 4133 if (LHS.isInvalid() || RHS.isInvalid()) 4134 return QualType(); 4135 return LHS.get()->getType(); 4136 } 4137 4138 // -- The second and third operands have pointer type, or one has pointer 4139 // type and the other is a null pointer constant; pointer conversions 4140 // and qualification conversions are performed to bring them to their 4141 // composite pointer type. The result is of the composite pointer type. 4142 // -- The second and third operands have pointer to member type, or one has 4143 // pointer to member type and the other is a null pointer constant; 4144 // pointer to member conversions and qualification conversions are 4145 // performed to bring them to a common type, whose cv-qualification 4146 // shall match the cv-qualification of either the second or the third 4147 // operand. The result is of the common type. 4148 bool NonStandardCompositeType = false; 4149 QualType Composite = FindCompositePointerType(QuestionLoc, LHS, RHS, 4150 isSFINAEContext()? 0 : &NonStandardCompositeType); 4151 if (!Composite.isNull()) { 4152 if (NonStandardCompositeType) 4153 Diag(QuestionLoc, 4154 diag::ext_typecheck_cond_incompatible_operands_nonstandard) 4155 << LTy << RTy << Composite 4156 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 4157 4158 return Composite; 4159 } 4160 4161 // Similarly, attempt to find composite type of two objective-c pointers. 4162 Composite = FindCompositeObjCPointerType(LHS, RHS, QuestionLoc); 4163 if (!Composite.isNull()) 4164 return Composite; 4165 4166 // Check if we are using a null with a non-pointer type. 4167 if (DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc)) 4168 return QualType(); 4169 4170 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 4171 << LHS.get()->getType() << RHS.get()->getType() 4172 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 4173 return QualType(); 4174} 4175 4176/// \brief Find a merged pointer type and convert the two expressions to it. 4177/// 4178/// This finds the composite pointer type (or member pointer type) for @p E1 4179/// and @p E2 according to C++0x 5.9p2. It converts both expressions to this 4180/// type and returns it. 4181/// It does not emit diagnostics. 4182/// 4183/// \param Loc The location of the operator requiring these two expressions to 4184/// be converted to the composite pointer type. 4185/// 4186/// If \p NonStandardCompositeType is non-NULL, then we are permitted to find 4187/// a non-standard (but still sane) composite type to which both expressions 4188/// can be converted. When such a type is chosen, \c *NonStandardCompositeType 4189/// will be set true. 4190QualType Sema::FindCompositePointerType(SourceLocation Loc, 4191 Expr *&E1, Expr *&E2, 4192 bool *NonStandardCompositeType) { 4193 if (NonStandardCompositeType) 4194 *NonStandardCompositeType = false; 4195 4196 assert(getLangOptions().CPlusPlus && "This function assumes C++"); 4197 QualType T1 = E1->getType(), T2 = E2->getType(); 4198 4199 if (!T1->isAnyPointerType() && !T1->isMemberPointerType() && 4200 !T2->isAnyPointerType() && !T2->isMemberPointerType()) 4201 return QualType(); 4202 4203 // C++0x 5.9p2 4204 // Pointer conversions and qualification conversions are performed on 4205 // pointer operands to bring them to their composite pointer type. If 4206 // one operand is a null pointer constant, the composite pointer type is 4207 // the type of the other operand. 4208 if (E1->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4209 if (T2->isMemberPointerType()) 4210 E1 = ImpCastExprToType(E1, T2, CK_NullToMemberPointer).take(); 4211 else 4212 E1 = ImpCastExprToType(E1, T2, CK_NullToPointer).take(); 4213 return T2; 4214 } 4215 if (E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 4216 if (T1->isMemberPointerType()) 4217 E2 = ImpCastExprToType(E2, T1, CK_NullToMemberPointer).take(); 4218 else 4219 E2 = ImpCastExprToType(E2, T1, CK_NullToPointer).take(); 4220 return T1; 4221 } 4222 4223 // Now both have to be pointers or member pointers. 4224 if ((!T1->isPointerType() && !T1->isMemberPointerType()) || 4225 (!T2->isPointerType() && !T2->isMemberPointerType())) 4226 return QualType(); 4227 4228 // Otherwise, of one of the operands has type "pointer to cv1 void," then 4229 // the other has type "pointer to cv2 T" and the composite pointer type is 4230 // "pointer to cv12 void," where cv12 is the union of cv1 and cv2. 4231 // Otherwise, the composite pointer type is a pointer type similar to the 4232 // type of one of the operands, with a cv-qualification signature that is 4233 // the union of the cv-qualification signatures of the operand types. 4234 // In practice, the first part here is redundant; it's subsumed by the second. 4235 // What we do here is, we build the two possible composite types, and try the 4236 // conversions in both directions. If only one works, or if the two composite 4237 // types are the same, we have succeeded. 4238 // FIXME: extended qualifiers? 4239 typedef SmallVector<unsigned, 4> QualifierVector; 4240 QualifierVector QualifierUnion; 4241 typedef SmallVector<std::pair<const Type *, const Type *>, 4> 4242 ContainingClassVector; 4243 ContainingClassVector MemberOfClass; 4244 QualType Composite1 = Context.getCanonicalType(T1), 4245 Composite2 = Context.getCanonicalType(T2); 4246 unsigned NeedConstBefore = 0; 4247 do { 4248 const PointerType *Ptr1, *Ptr2; 4249 if ((Ptr1 = Composite1->getAs<PointerType>()) && 4250 (Ptr2 = Composite2->getAs<PointerType>())) { 4251 Composite1 = Ptr1->getPointeeType(); 4252 Composite2 = Ptr2->getPointeeType(); 4253 4254 // If we're allowed to create a non-standard composite type, keep track 4255 // of where we need to fill in additional 'const' qualifiers. 4256 if (NonStandardCompositeType && 4257 Composite1.getCVRQualifiers() != Composite2.getCVRQualifiers()) 4258 NeedConstBefore = QualifierUnion.size(); 4259 4260 QualifierUnion.push_back( 4261 Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers()); 4262 MemberOfClass.push_back(std::make_pair((const Type *)0, (const Type *)0)); 4263 continue; 4264 } 4265 4266 const MemberPointerType *MemPtr1, *MemPtr2; 4267 if ((MemPtr1 = Composite1->getAs<MemberPointerType>()) && 4268 (MemPtr2 = Composite2->getAs<MemberPointerType>())) { 4269 Composite1 = MemPtr1->getPointeeType(); 4270 Composite2 = MemPtr2->getPointeeType(); 4271 4272 // If we're allowed to create a non-standard composite type, keep track 4273 // of where we need to fill in additional 'const' qualifiers. 4274 if (NonStandardCompositeType && 4275 Composite1.getCVRQualifiers() != Composite2.getCVRQualifiers()) 4276 NeedConstBefore = QualifierUnion.size(); 4277 4278 QualifierUnion.push_back( 4279 Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers()); 4280 MemberOfClass.push_back(std::make_pair(MemPtr1->getClass(), 4281 MemPtr2->getClass())); 4282 continue; 4283 } 4284 4285 // FIXME: block pointer types? 4286 4287 // Cannot unwrap any more types. 4288 break; 4289 } while (true); 4290 4291 if (NeedConstBefore && NonStandardCompositeType) { 4292 // Extension: Add 'const' to qualifiers that come before the first qualifier 4293 // mismatch, so that our (non-standard!) composite type meets the 4294 // requirements of C++ [conv.qual]p4 bullet 3. 4295 for (unsigned I = 0; I != NeedConstBefore; ++I) { 4296 if ((QualifierUnion[I] & Qualifiers::Const) == 0) { 4297 QualifierUnion[I] = QualifierUnion[I] | Qualifiers::Const; 4298 *NonStandardCompositeType = true; 4299 } 4300 } 4301 } 4302 4303 // Rewrap the composites as pointers or member pointers with the union CVRs. 4304 ContainingClassVector::reverse_iterator MOC 4305 = MemberOfClass.rbegin(); 4306 for (QualifierVector::reverse_iterator 4307 I = QualifierUnion.rbegin(), 4308 E = QualifierUnion.rend(); 4309 I != E; (void)++I, ++MOC) { 4310 Qualifiers Quals = Qualifiers::fromCVRMask(*I); 4311 if (MOC->first && MOC->second) { 4312 // Rebuild member pointer type 4313 Composite1 = Context.getMemberPointerType( 4314 Context.getQualifiedType(Composite1, Quals), 4315 MOC->first); 4316 Composite2 = Context.getMemberPointerType( 4317 Context.getQualifiedType(Composite2, Quals), 4318 MOC->second); 4319 } else { 4320 // Rebuild pointer type 4321 Composite1 4322 = Context.getPointerType(Context.getQualifiedType(Composite1, Quals)); 4323 Composite2 4324 = Context.getPointerType(Context.getQualifiedType(Composite2, Quals)); 4325 } 4326 } 4327 4328 // Try to convert to the first composite pointer type. 4329 InitializedEntity Entity1 4330 = InitializedEntity::InitializeTemporary(Composite1); 4331 InitializationKind Kind 4332 = InitializationKind::CreateCopy(Loc, SourceLocation()); 4333 InitializationSequence E1ToC1(*this, Entity1, Kind, &E1, 1); 4334 InitializationSequence E2ToC1(*this, Entity1, Kind, &E2, 1); 4335 4336 if (E1ToC1 && E2ToC1) { 4337 // Conversion to Composite1 is viable. 4338 if (!Context.hasSameType(Composite1, Composite2)) { 4339 // Composite2 is a different type from Composite1. Check whether 4340 // Composite2 is also viable. 4341 InitializedEntity Entity2 4342 = InitializedEntity::InitializeTemporary(Composite2); 4343 InitializationSequence E1ToC2(*this, Entity2, Kind, &E1, 1); 4344 InitializationSequence E2ToC2(*this, Entity2, Kind, &E2, 1); 4345 if (E1ToC2 && E2ToC2) { 4346 // Both Composite1 and Composite2 are viable and are different; 4347 // this is an ambiguity. 4348 return QualType(); 4349 } 4350 } 4351 4352 // Convert E1 to Composite1 4353 ExprResult E1Result 4354 = E1ToC1.Perform(*this, Entity1, Kind, MultiExprArg(*this,&E1,1)); 4355 if (E1Result.isInvalid()) 4356 return QualType(); 4357 E1 = E1Result.takeAs<Expr>(); 4358 4359 // Convert E2 to Composite1 4360 ExprResult E2Result 4361 = E2ToC1.Perform(*this, Entity1, Kind, MultiExprArg(*this,&E2,1)); 4362 if (E2Result.isInvalid()) 4363 return QualType(); 4364 E2 = E2Result.takeAs<Expr>(); 4365 4366 return Composite1; 4367 } 4368 4369 // Check whether Composite2 is viable. 4370 InitializedEntity Entity2 4371 = InitializedEntity::InitializeTemporary(Composite2); 4372 InitializationSequence E1ToC2(*this, Entity2, Kind, &E1, 1); 4373 InitializationSequence E2ToC2(*this, Entity2, Kind, &E2, 1); 4374 if (!E1ToC2 || !E2ToC2) 4375 return QualType(); 4376 4377 // Convert E1 to Composite2 4378 ExprResult E1Result 4379 = E1ToC2.Perform(*this, Entity2, Kind, MultiExprArg(*this, &E1, 1)); 4380 if (E1Result.isInvalid()) 4381 return QualType(); 4382 E1 = E1Result.takeAs<Expr>(); 4383 4384 // Convert E2 to Composite2 4385 ExprResult E2Result 4386 = E2ToC2.Perform(*this, Entity2, Kind, MultiExprArg(*this, &E2, 1)); 4387 if (E2Result.isInvalid()) 4388 return QualType(); 4389 E2 = E2Result.takeAs<Expr>(); 4390 4391 return Composite2; 4392} 4393 4394ExprResult Sema::MaybeBindToTemporary(Expr *E) { 4395 if (!E) 4396 return ExprError(); 4397 4398 assert(!isa<CXXBindTemporaryExpr>(E) && "Double-bound temporary?"); 4399 4400 // If the result is a glvalue, we shouldn't bind it. 4401 if (!E->isRValue()) 4402 return Owned(E); 4403 4404 // In ARC, calls that return a retainable type can return retained, 4405 // in which case we have to insert a consuming cast. 4406 if (getLangOptions().ObjCAutoRefCount && 4407 E->getType()->isObjCRetainableType()) { 4408 4409 bool ReturnsRetained; 4410 4411 // For actual calls, we compute this by examining the type of the 4412 // called value. 4413 if (CallExpr *Call = dyn_cast<CallExpr>(E)) { 4414 Expr *Callee = Call->getCallee()->IgnoreParens(); 4415 QualType T = Callee->getType(); 4416 4417 if (T == Context.BoundMemberTy) { 4418 // Handle pointer-to-members. 4419 if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(Callee)) 4420 T = BinOp->getRHS()->getType(); 4421 else if (MemberExpr *Mem = dyn_cast<MemberExpr>(Callee)) 4422 T = Mem->getMemberDecl()->getType(); 4423 } 4424 4425 if (const PointerType *Ptr = T->getAs<PointerType>()) 4426 T = Ptr->getPointeeType(); 4427 else if (const BlockPointerType *Ptr = T->getAs<BlockPointerType>()) 4428 T = Ptr->getPointeeType(); 4429 else if (const MemberPointerType *MemPtr = T->getAs<MemberPointerType>()) 4430 T = MemPtr->getPointeeType(); 4431 4432 const FunctionType *FTy = T->getAs<FunctionType>(); 4433 assert(FTy && "call to value not of function type?"); 4434 ReturnsRetained = FTy->getExtInfo().getProducesResult(); 4435 4436 // ActOnStmtExpr arranges things so that StmtExprs of retainable 4437 // type always produce a +1 object. 4438 } else if (isa<StmtExpr>(E)) { 4439 ReturnsRetained = true; 4440 4441 // For message sends and property references, we try to find an 4442 // actual method. FIXME: we should infer retention by selector in 4443 // cases where we don't have an actual method. 4444 } else { 4445 ObjCMethodDecl *D = 0; 4446 if (ObjCMessageExpr *Send = dyn_cast<ObjCMessageExpr>(E)) { 4447 D = Send->getMethodDecl(); 4448 } 4449 4450 ReturnsRetained = (D && D->hasAttr<NSReturnsRetainedAttr>()); 4451 4452 // Don't do reclaims on performSelector calls; despite their 4453 // return type, the invoked method doesn't necessarily actually 4454 // return an object. 4455 if (!ReturnsRetained && 4456 D && D->getMethodFamily() == OMF_performSelector) 4457 return Owned(E); 4458 } 4459 4460 // Don't reclaim an object of Class type. 4461 if (!ReturnsRetained && E->getType()->isObjCARCImplicitlyUnretainedType()) 4462 return Owned(E); 4463 4464 ExprNeedsCleanups = true; 4465 4466 CastKind ck = (ReturnsRetained ? CK_ARCConsumeObject 4467 : CK_ARCReclaimReturnedObject); 4468 return Owned(ImplicitCastExpr::Create(Context, E->getType(), ck, E, 0, 4469 VK_RValue)); 4470 } 4471 4472 if (!getLangOptions().CPlusPlus) 4473 return Owned(E); 4474 4475 // Search for the base element type (cf. ASTContext::getBaseElementType) with 4476 // a fast path for the common case that the type is directly a RecordType. 4477 const Type *T = Context.getCanonicalType(E->getType().getTypePtr()); 4478 const RecordType *RT = 0; 4479 while (!RT) { 4480 switch (T->getTypeClass()) { 4481 case Type::Record: 4482 RT = cast<RecordType>(T); 4483 break; 4484 case Type::ConstantArray: 4485 case Type::IncompleteArray: 4486 case Type::VariableArray: 4487 case Type::DependentSizedArray: 4488 T = cast<ArrayType>(T)->getElementType().getTypePtr(); 4489 break; 4490 default: 4491 return Owned(E); 4492 } 4493 } 4494 4495 // That should be enough to guarantee that this type is complete, if we're 4496 // not processing a decltype expression. 4497 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 4498 if (RD->isInvalidDecl() || RD->isDependentContext()) 4499 return Owned(E); 4500 4501 bool IsDecltype = ExprEvalContexts.back().IsDecltype; 4502 CXXDestructorDecl *Destructor = IsDecltype ? 0 : LookupDestructor(RD); 4503 4504 if (Destructor) { 4505 MarkFunctionReferenced(E->getExprLoc(), Destructor); 4506 CheckDestructorAccess(E->getExprLoc(), Destructor, 4507 PDiag(diag::err_access_dtor_temp) 4508 << E->getType()); 4509 DiagnoseUseOfDecl(Destructor, E->getExprLoc()); 4510 4511 // If destructor is trivial, we can avoid the extra copy. 4512 if (Destructor->isTrivial()) 4513 return Owned(E); 4514 4515 // We need a cleanup, but we don't need to remember the temporary. 4516 ExprNeedsCleanups = true; 4517 } 4518 4519 CXXTemporary *Temp = CXXTemporary::Create(Context, Destructor); 4520 CXXBindTemporaryExpr *Bind = CXXBindTemporaryExpr::Create(Context, Temp, E); 4521 4522 if (IsDecltype) 4523 ExprEvalContexts.back().DelayedDecltypeBinds.push_back(Bind); 4524 4525 return Owned(Bind); 4526} 4527 4528ExprResult 4529Sema::MaybeCreateExprWithCleanups(ExprResult SubExpr) { 4530 if (SubExpr.isInvalid()) 4531 return ExprError(); 4532 4533 return Owned(MaybeCreateExprWithCleanups(SubExpr.take())); 4534} 4535 4536Expr *Sema::MaybeCreateExprWithCleanups(Expr *SubExpr) { 4537 assert(SubExpr && "sub expression can't be null!"); 4538 4539 CleanupVarDeclMarking(); 4540 4541 unsigned FirstCleanup = ExprEvalContexts.back().NumCleanupObjects; 4542 assert(ExprCleanupObjects.size() >= FirstCleanup); 4543 assert(ExprNeedsCleanups || ExprCleanupObjects.size() == FirstCleanup); 4544 if (!ExprNeedsCleanups) 4545 return SubExpr; 4546 4547 ArrayRef<ExprWithCleanups::CleanupObject> Cleanups 4548 = llvm::makeArrayRef(ExprCleanupObjects.begin() + FirstCleanup, 4549 ExprCleanupObjects.size() - FirstCleanup); 4550 4551 Expr *E = ExprWithCleanups::Create(Context, SubExpr, Cleanups); 4552 DiscardCleanupsInEvaluationContext(); 4553 4554 return E; 4555} 4556 4557Stmt *Sema::MaybeCreateStmtWithCleanups(Stmt *SubStmt) { 4558 assert(SubStmt && "sub statement can't be null!"); 4559 4560 CleanupVarDeclMarking(); 4561 4562 if (!ExprNeedsCleanups) 4563 return SubStmt; 4564 4565 // FIXME: In order to attach the temporaries, wrap the statement into 4566 // a StmtExpr; currently this is only used for asm statements. 4567 // This is hacky, either create a new CXXStmtWithTemporaries statement or 4568 // a new AsmStmtWithTemporaries. 4569 CompoundStmt *CompStmt = new (Context) CompoundStmt(Context, &SubStmt, 1, 4570 SourceLocation(), 4571 SourceLocation()); 4572 Expr *E = new (Context) StmtExpr(CompStmt, Context.VoidTy, SourceLocation(), 4573 SourceLocation()); 4574 return MaybeCreateExprWithCleanups(E); 4575} 4576 4577/// Process the expression contained within a decltype. For such expressions, 4578/// certain semantic checks on temporaries are delayed until this point, and 4579/// are omitted for the 'topmost' call in the decltype expression. If the 4580/// topmost call bound a temporary, strip that temporary off the expression. 4581ExprResult Sema::ActOnDecltypeExpression(Expr *E) { 4582 ExpressionEvaluationContextRecord &Rec = ExprEvalContexts.back(); 4583 assert(Rec.IsDecltype && "not in a decltype expression"); 4584 4585 // C++11 [expr.call]p11: 4586 // If a function call is a prvalue of object type, 4587 // -- if the function call is either 4588 // -- the operand of a decltype-specifier, or 4589 // -- the right operand of a comma operator that is the operand of a 4590 // decltype-specifier, 4591 // a temporary object is not introduced for the prvalue. 4592 4593 // Recursively rebuild ParenExprs and comma expressions to strip out the 4594 // outermost CXXBindTemporaryExpr, if any. 4595 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 4596 ExprResult SubExpr = ActOnDecltypeExpression(PE->getSubExpr()); 4597 if (SubExpr.isInvalid()) 4598 return ExprError(); 4599 if (SubExpr.get() == PE->getSubExpr()) 4600 return Owned(E); 4601 return ActOnParenExpr(PE->getLParen(), PE->getRParen(), SubExpr.take()); 4602 } 4603 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) { 4604 if (BO->getOpcode() == BO_Comma) { 4605 ExprResult RHS = ActOnDecltypeExpression(BO->getRHS()); 4606 if (RHS.isInvalid()) 4607 return ExprError(); 4608 if (RHS.get() == BO->getRHS()) 4609 return Owned(E); 4610 return Owned(new (Context) BinaryOperator(BO->getLHS(), RHS.take(), 4611 BO_Comma, BO->getType(), 4612 BO->getValueKind(), 4613 BO->getObjectKind(), 4614 BO->getOperatorLoc())); 4615 } 4616 } 4617 4618 CXXBindTemporaryExpr *TopBind = dyn_cast<CXXBindTemporaryExpr>(E); 4619 if (TopBind) 4620 E = TopBind->getSubExpr(); 4621 4622 // Disable the special decltype handling now. 4623 Rec.IsDecltype = false; 4624 4625 // Perform the semantic checks we delayed until this point. 4626 CallExpr *TopCall = dyn_cast<CallExpr>(E); 4627 for (unsigned I = 0, N = Rec.DelayedDecltypeCalls.size(); I != N; ++I) { 4628 CallExpr *Call = Rec.DelayedDecltypeCalls[I]; 4629 if (Call == TopCall) 4630 continue; 4631 4632 if (CheckCallReturnType(Call->getCallReturnType(), 4633 Call->getSourceRange().getBegin(), 4634 Call, Call->getDirectCallee())) 4635 return ExprError(); 4636 } 4637 4638 // Now all relevant types are complete, check the destructors are accessible 4639 // and non-deleted, and annotate them on the temporaries. 4640 for (unsigned I = 0, N = Rec.DelayedDecltypeBinds.size(); I != N; ++I) { 4641 CXXBindTemporaryExpr *Bind = Rec.DelayedDecltypeBinds[I]; 4642 if (Bind == TopBind) 4643 continue; 4644 4645 CXXTemporary *Temp = Bind->getTemporary(); 4646 4647 CXXRecordDecl *RD = 4648 Bind->getType()->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); 4649 CXXDestructorDecl *Destructor = LookupDestructor(RD); 4650 Temp->setDestructor(Destructor); 4651 4652 MarkFunctionReferenced(E->getExprLoc(), Destructor); 4653 CheckDestructorAccess(E->getExprLoc(), Destructor, 4654 PDiag(diag::err_access_dtor_temp) 4655 << E->getType()); 4656 DiagnoseUseOfDecl(Destructor, E->getExprLoc()); 4657 4658 // We need a cleanup, but we don't need to remember the temporary. 4659 ExprNeedsCleanups = true; 4660 } 4661 4662 // Possibly strip off the top CXXBindTemporaryExpr. 4663 return Owned(E); 4664} 4665 4666ExprResult 4667Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base, SourceLocation OpLoc, 4668 tok::TokenKind OpKind, ParsedType &ObjectType, 4669 bool &MayBePseudoDestructor) { 4670 // Since this might be a postfix expression, get rid of ParenListExprs. 4671 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base); 4672 if (Result.isInvalid()) return ExprError(); 4673 Base = Result.get(); 4674 4675 Result = CheckPlaceholderExpr(Base); 4676 if (Result.isInvalid()) return ExprError(); 4677 Base = Result.take(); 4678 4679 QualType BaseType = Base->getType(); 4680 MayBePseudoDestructor = false; 4681 if (BaseType->isDependentType()) { 4682 // If we have a pointer to a dependent type and are using the -> operator, 4683 // the object type is the type that the pointer points to. We might still 4684 // have enough information about that type to do something useful. 4685 if (OpKind == tok::arrow) 4686 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) 4687 BaseType = Ptr->getPointeeType(); 4688 4689 ObjectType = ParsedType::make(BaseType); 4690 MayBePseudoDestructor = true; 4691 return Owned(Base); 4692 } 4693 4694 // C++ [over.match.oper]p8: 4695 // [...] When operator->returns, the operator-> is applied to the value 4696 // returned, with the original second operand. 4697 if (OpKind == tok::arrow) { 4698 // The set of types we've considered so far. 4699 llvm::SmallPtrSet<CanQualType,8> CTypes; 4700 SmallVector<SourceLocation, 8> Locations; 4701 CTypes.insert(Context.getCanonicalType(BaseType)); 4702 4703 while (BaseType->isRecordType()) { 4704 Result = BuildOverloadedArrowExpr(S, Base, OpLoc); 4705 if (Result.isInvalid()) 4706 return ExprError(); 4707 Base = Result.get(); 4708 if (CXXOperatorCallExpr *OpCall = dyn_cast<CXXOperatorCallExpr>(Base)) 4709 Locations.push_back(OpCall->getDirectCallee()->getLocation()); 4710 BaseType = Base->getType(); 4711 CanQualType CBaseType = Context.getCanonicalType(BaseType); 4712 if (!CTypes.insert(CBaseType)) { 4713 Diag(OpLoc, diag::err_operator_arrow_circular); 4714 for (unsigned i = 0; i < Locations.size(); i++) 4715 Diag(Locations[i], diag::note_declared_at); 4716 return ExprError(); 4717 } 4718 } 4719 4720 if (BaseType->isPointerType() || BaseType->isObjCObjectPointerType()) 4721 BaseType = BaseType->getPointeeType(); 4722 } 4723 4724 // Objective-C properties allow "." access on Objective-C pointer types, 4725 // so adjust the base type to the object type itself. 4726 if (BaseType->isObjCObjectPointerType()) 4727 BaseType = BaseType->getPointeeType(); 4728 4729 // C++ [basic.lookup.classref]p2: 4730 // [...] If the type of the object expression is of pointer to scalar 4731 // type, the unqualified-id is looked up in the context of the complete 4732 // postfix-expression. 4733 // 4734 // This also indicates that we could be parsing a pseudo-destructor-name. 4735 // Note that Objective-C class and object types can be pseudo-destructor 4736 // expressions or normal member (ivar or property) access expressions. 4737 if (BaseType->isObjCObjectOrInterfaceType()) { 4738 MayBePseudoDestructor = true; 4739 } else if (!BaseType->isRecordType()) { 4740 ObjectType = ParsedType(); 4741 MayBePseudoDestructor = true; 4742 return Owned(Base); 4743 } 4744 4745 // The object type must be complete (or dependent). 4746 if (!BaseType->isDependentType() && 4747 RequireCompleteType(OpLoc, BaseType, 4748 PDiag(diag::err_incomplete_member_access))) 4749 return ExprError(); 4750 4751 // C++ [basic.lookup.classref]p2: 4752 // If the id-expression in a class member access (5.2.5) is an 4753 // unqualified-id, and the type of the object expression is of a class 4754 // type C (or of pointer to a class type C), the unqualified-id is looked 4755 // up in the scope of class C. [...] 4756 ObjectType = ParsedType::make(BaseType); 4757 return move(Base); 4758} 4759 4760ExprResult Sema::DiagnoseDtorReference(SourceLocation NameLoc, 4761 Expr *MemExpr) { 4762 SourceLocation ExpectedLParenLoc = PP.getLocForEndOfToken(NameLoc); 4763 Diag(MemExpr->getLocStart(), diag::err_dtor_expr_without_call) 4764 << isa<CXXPseudoDestructorExpr>(MemExpr) 4765 << FixItHint::CreateInsertion(ExpectedLParenLoc, "()"); 4766 4767 return ActOnCallExpr(/*Scope*/ 0, 4768 MemExpr, 4769 /*LPLoc*/ ExpectedLParenLoc, 4770 MultiExprArg(), 4771 /*RPLoc*/ ExpectedLParenLoc); 4772} 4773 4774static bool CheckArrow(Sema& S, QualType& ObjectType, Expr *&Base, 4775 tok::TokenKind& OpKind, SourceLocation OpLoc) { 4776 if (Base->hasPlaceholderType()) { 4777 ExprResult result = S.CheckPlaceholderExpr(Base); 4778 if (result.isInvalid()) return true; 4779 Base = result.take(); 4780 } 4781 ObjectType = Base->getType(); 4782 4783 // C++ [expr.pseudo]p2: 4784 // The left-hand side of the dot operator shall be of scalar type. The 4785 // left-hand side of the arrow operator shall be of pointer to scalar type. 4786 // This scalar type is the object type. 4787 // Note that this is rather different from the normal handling for the 4788 // arrow operator. 4789 if (OpKind == tok::arrow) { 4790 if (const PointerType *Ptr = ObjectType->getAs<PointerType>()) { 4791 ObjectType = Ptr->getPointeeType(); 4792 } else if (!Base->isTypeDependent()) { 4793 // The user wrote "p->" when she probably meant "p."; fix it. 4794 S.Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 4795 << ObjectType << true 4796 << FixItHint::CreateReplacement(OpLoc, "."); 4797 if (S.isSFINAEContext()) 4798 return true; 4799 4800 OpKind = tok::period; 4801 } 4802 } 4803 4804 return false; 4805} 4806 4807ExprResult Sema::BuildPseudoDestructorExpr(Expr *Base, 4808 SourceLocation OpLoc, 4809 tok::TokenKind OpKind, 4810 const CXXScopeSpec &SS, 4811 TypeSourceInfo *ScopeTypeInfo, 4812 SourceLocation CCLoc, 4813 SourceLocation TildeLoc, 4814 PseudoDestructorTypeStorage Destructed, 4815 bool HasTrailingLParen) { 4816 TypeSourceInfo *DestructedTypeInfo = Destructed.getTypeSourceInfo(); 4817 4818 QualType ObjectType; 4819 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) 4820 return ExprError(); 4821 4822 if (!ObjectType->isDependentType() && !ObjectType->isScalarType()) { 4823 if (getLangOptions().MicrosoftMode && ObjectType->isVoidType()) 4824 Diag(OpLoc, diag::ext_pseudo_dtor_on_void) << Base->getSourceRange(); 4825 else 4826 Diag(OpLoc, diag::err_pseudo_dtor_base_not_scalar) 4827 << ObjectType << Base->getSourceRange(); 4828 return ExprError(); 4829 } 4830 4831 // C++ [expr.pseudo]p2: 4832 // [...] The cv-unqualified versions of the object type and of the type 4833 // designated by the pseudo-destructor-name shall be the same type. 4834 if (DestructedTypeInfo) { 4835 QualType DestructedType = DestructedTypeInfo->getType(); 4836 SourceLocation DestructedTypeStart 4837 = DestructedTypeInfo->getTypeLoc().getLocalSourceRange().getBegin(); 4838 if (!DestructedType->isDependentType() && !ObjectType->isDependentType()) { 4839 if (!Context.hasSameUnqualifiedType(DestructedType, ObjectType)) { 4840 Diag(DestructedTypeStart, diag::err_pseudo_dtor_type_mismatch) 4841 << ObjectType << DestructedType << Base->getSourceRange() 4842 << DestructedTypeInfo->getTypeLoc().getLocalSourceRange(); 4843 4844 // Recover by setting the destructed type to the object type. 4845 DestructedType = ObjectType; 4846 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(ObjectType, 4847 DestructedTypeStart); 4848 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); 4849 } else if (DestructedType.getObjCLifetime() != 4850 ObjectType.getObjCLifetime()) { 4851 4852 if (DestructedType.getObjCLifetime() == Qualifiers::OCL_None) { 4853 // Okay: just pretend that the user provided the correctly-qualified 4854 // type. 4855 } else { 4856 Diag(DestructedTypeStart, diag::err_arc_pseudo_dtor_inconstant_quals) 4857 << ObjectType << DestructedType << Base->getSourceRange() 4858 << DestructedTypeInfo->getTypeLoc().getLocalSourceRange(); 4859 } 4860 4861 // Recover by setting the destructed type to the object type. 4862 DestructedType = ObjectType; 4863 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(ObjectType, 4864 DestructedTypeStart); 4865 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); 4866 } 4867 } 4868 } 4869 4870 // C++ [expr.pseudo]p2: 4871 // [...] Furthermore, the two type-names in a pseudo-destructor-name of the 4872 // form 4873 // 4874 // ::[opt] nested-name-specifier[opt] type-name :: ~ type-name 4875 // 4876 // shall designate the same scalar type. 4877 if (ScopeTypeInfo) { 4878 QualType ScopeType = ScopeTypeInfo->getType(); 4879 if (!ScopeType->isDependentType() && !ObjectType->isDependentType() && 4880 !Context.hasSameUnqualifiedType(ScopeType, ObjectType)) { 4881 4882 Diag(ScopeTypeInfo->getTypeLoc().getLocalSourceRange().getBegin(), 4883 diag::err_pseudo_dtor_type_mismatch) 4884 << ObjectType << ScopeType << Base->getSourceRange() 4885 << ScopeTypeInfo->getTypeLoc().getLocalSourceRange(); 4886 4887 ScopeType = QualType(); 4888 ScopeTypeInfo = 0; 4889 } 4890 } 4891 4892 Expr *Result 4893 = new (Context) CXXPseudoDestructorExpr(Context, Base, 4894 OpKind == tok::arrow, OpLoc, 4895 SS.getWithLocInContext(Context), 4896 ScopeTypeInfo, 4897 CCLoc, 4898 TildeLoc, 4899 Destructed); 4900 4901 if (HasTrailingLParen) 4902 return Owned(Result); 4903 4904 return DiagnoseDtorReference(Destructed.getLocation(), Result); 4905} 4906 4907ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base, 4908 SourceLocation OpLoc, 4909 tok::TokenKind OpKind, 4910 CXXScopeSpec &SS, 4911 UnqualifiedId &FirstTypeName, 4912 SourceLocation CCLoc, 4913 SourceLocation TildeLoc, 4914 UnqualifiedId &SecondTypeName, 4915 bool HasTrailingLParen) { 4916 assert((FirstTypeName.getKind() == UnqualifiedId::IK_TemplateId || 4917 FirstTypeName.getKind() == UnqualifiedId::IK_Identifier) && 4918 "Invalid first type name in pseudo-destructor"); 4919 assert((SecondTypeName.getKind() == UnqualifiedId::IK_TemplateId || 4920 SecondTypeName.getKind() == UnqualifiedId::IK_Identifier) && 4921 "Invalid second type name in pseudo-destructor"); 4922 4923 QualType ObjectType; 4924 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) 4925 return ExprError(); 4926 4927 // Compute the object type that we should use for name lookup purposes. Only 4928 // record types and dependent types matter. 4929 ParsedType ObjectTypePtrForLookup; 4930 if (!SS.isSet()) { 4931 if (ObjectType->isRecordType()) 4932 ObjectTypePtrForLookup = ParsedType::make(ObjectType); 4933 else if (ObjectType->isDependentType()) 4934 ObjectTypePtrForLookup = ParsedType::make(Context.DependentTy); 4935 } 4936 4937 // Convert the name of the type being destructed (following the ~) into a 4938 // type (with source-location information). 4939 QualType DestructedType; 4940 TypeSourceInfo *DestructedTypeInfo = 0; 4941 PseudoDestructorTypeStorage Destructed; 4942 if (SecondTypeName.getKind() == UnqualifiedId::IK_Identifier) { 4943 ParsedType T = getTypeName(*SecondTypeName.Identifier, 4944 SecondTypeName.StartLocation, 4945 S, &SS, true, false, ObjectTypePtrForLookup); 4946 if (!T && 4947 ((SS.isSet() && !computeDeclContext(SS, false)) || 4948 (!SS.isSet() && ObjectType->isDependentType()))) { 4949 // The name of the type being destroyed is a dependent name, and we 4950 // couldn't find anything useful in scope. Just store the identifier and 4951 // it's location, and we'll perform (qualified) name lookup again at 4952 // template instantiation time. 4953 Destructed = PseudoDestructorTypeStorage(SecondTypeName.Identifier, 4954 SecondTypeName.StartLocation); 4955 } else if (!T) { 4956 Diag(SecondTypeName.StartLocation, 4957 diag::err_pseudo_dtor_destructor_non_type) 4958 << SecondTypeName.Identifier << ObjectType; 4959 if (isSFINAEContext()) 4960 return ExprError(); 4961 4962 // Recover by assuming we had the right type all along. 4963 DestructedType = ObjectType; 4964 } else 4965 DestructedType = GetTypeFromParser(T, &DestructedTypeInfo); 4966 } else { 4967 // Resolve the template-id to a type. 4968 TemplateIdAnnotation *TemplateId = SecondTypeName.TemplateId; 4969 ASTTemplateArgsPtr TemplateArgsPtr(*this, 4970 TemplateId->getTemplateArgs(), 4971 TemplateId->NumArgs); 4972 TypeResult T = ActOnTemplateIdType(TemplateId->SS, 4973 TemplateId->TemplateKWLoc, 4974 TemplateId->Template, 4975 TemplateId->TemplateNameLoc, 4976 TemplateId->LAngleLoc, 4977 TemplateArgsPtr, 4978 TemplateId->RAngleLoc); 4979 if (T.isInvalid() || !T.get()) { 4980 // Recover by assuming we had the right type all along. 4981 DestructedType = ObjectType; 4982 } else 4983 DestructedType = GetTypeFromParser(T.get(), &DestructedTypeInfo); 4984 } 4985 4986 // If we've performed some kind of recovery, (re-)build the type source 4987 // information. 4988 if (!DestructedType.isNull()) { 4989 if (!DestructedTypeInfo) 4990 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(DestructedType, 4991 SecondTypeName.StartLocation); 4992 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); 4993 } 4994 4995 // Convert the name of the scope type (the type prior to '::') into a type. 4996 TypeSourceInfo *ScopeTypeInfo = 0; 4997 QualType ScopeType; 4998 if (FirstTypeName.getKind() == UnqualifiedId::IK_TemplateId || 4999 FirstTypeName.Identifier) { 5000 if (FirstTypeName.getKind() == UnqualifiedId::IK_Identifier) { 5001 ParsedType T = getTypeName(*FirstTypeName.Identifier, 5002 FirstTypeName.StartLocation, 5003 S, &SS, true, false, ObjectTypePtrForLookup); 5004 if (!T) { 5005 Diag(FirstTypeName.StartLocation, 5006 diag::err_pseudo_dtor_destructor_non_type) 5007 << FirstTypeName.Identifier << ObjectType; 5008 5009 if (isSFINAEContext()) 5010 return ExprError(); 5011 5012 // Just drop this type. It's unnecessary anyway. 5013 ScopeType = QualType(); 5014 } else 5015 ScopeType = GetTypeFromParser(T, &ScopeTypeInfo); 5016 } else { 5017 // Resolve the template-id to a type. 5018 TemplateIdAnnotation *TemplateId = FirstTypeName.TemplateId; 5019 ASTTemplateArgsPtr TemplateArgsPtr(*this, 5020 TemplateId->getTemplateArgs(), 5021 TemplateId->NumArgs); 5022 TypeResult T = ActOnTemplateIdType(TemplateId->SS, 5023 TemplateId->TemplateKWLoc, 5024 TemplateId->Template, 5025 TemplateId->TemplateNameLoc, 5026 TemplateId->LAngleLoc, 5027 TemplateArgsPtr, 5028 TemplateId->RAngleLoc); 5029 if (T.isInvalid() || !T.get()) { 5030 // Recover by dropping this type. 5031 ScopeType = QualType(); 5032 } else 5033 ScopeType = GetTypeFromParser(T.get(), &ScopeTypeInfo); 5034 } 5035 } 5036 5037 if (!ScopeType.isNull() && !ScopeTypeInfo) 5038 ScopeTypeInfo = Context.getTrivialTypeSourceInfo(ScopeType, 5039 FirstTypeName.StartLocation); 5040 5041 5042 return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, SS, 5043 ScopeTypeInfo, CCLoc, TildeLoc, 5044 Destructed, HasTrailingLParen); 5045} 5046 5047ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base, 5048 SourceLocation OpLoc, 5049 tok::TokenKind OpKind, 5050 SourceLocation TildeLoc, 5051 const DeclSpec& DS, 5052 bool HasTrailingLParen) { 5053 QualType ObjectType; 5054 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) 5055 return ExprError(); 5056 5057 QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc()); 5058 5059 TypeLocBuilder TLB; 5060 DecltypeTypeLoc DecltypeTL = TLB.push<DecltypeTypeLoc>(T); 5061 DecltypeTL.setNameLoc(DS.getTypeSpecTypeLoc()); 5062 TypeSourceInfo *DestructedTypeInfo = TLB.getTypeSourceInfo(Context, T); 5063 PseudoDestructorTypeStorage Destructed(DestructedTypeInfo); 5064 5065 return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, CXXScopeSpec(), 5066 0, SourceLocation(), TildeLoc, 5067 Destructed, HasTrailingLParen); 5068} 5069 5070ExprResult Sema::BuildCXXMemberCallExpr(Expr *E, NamedDecl *FoundDecl, 5071 CXXMethodDecl *Method, 5072 bool HadMultipleCandidates) { 5073 ExprResult Exp = PerformObjectArgumentInitialization(E, /*Qualifier=*/0, 5074 FoundDecl, Method); 5075 if (Exp.isInvalid()) 5076 return true; 5077 5078 MemberExpr *ME = 5079 new (Context) MemberExpr(Exp.take(), /*IsArrow=*/false, Method, 5080 SourceLocation(), Context.BoundMemberTy, 5081 VK_RValue, OK_Ordinary); 5082 if (HadMultipleCandidates) 5083 ME->setHadMultipleCandidates(true); 5084 5085 QualType ResultType = Method->getResultType(); 5086 ExprValueKind VK = Expr::getValueKindForType(ResultType); 5087 ResultType = ResultType.getNonLValueExprType(Context); 5088 5089 MarkFunctionReferenced(Exp.get()->getLocStart(), Method); 5090 CXXMemberCallExpr *CE = 5091 new (Context) CXXMemberCallExpr(Context, ME, 0, 0, ResultType, VK, 5092 Exp.get()->getLocEnd()); 5093 return CE; 5094} 5095 5096ExprResult Sema::BuildCXXNoexceptExpr(SourceLocation KeyLoc, Expr *Operand, 5097 SourceLocation RParen) { 5098 return Owned(new (Context) CXXNoexceptExpr(Context.BoolTy, Operand, 5099 Operand->CanThrow(Context), 5100 KeyLoc, RParen)); 5101} 5102 5103ExprResult Sema::ActOnNoexceptExpr(SourceLocation KeyLoc, SourceLocation, 5104 Expr *Operand, SourceLocation RParen) { 5105 return BuildCXXNoexceptExpr(KeyLoc, Operand, RParen); 5106} 5107 5108/// Perform the conversions required for an expression used in a 5109/// context that ignores the result. 5110ExprResult Sema::IgnoredValueConversions(Expr *E) { 5111 if (E->hasPlaceholderType()) { 5112 ExprResult result = CheckPlaceholderExpr(E); 5113 if (result.isInvalid()) return Owned(E); 5114 E = result.take(); 5115 } 5116 5117 // C99 6.3.2.1: 5118 // [Except in specific positions,] an lvalue that does not have 5119 // array type is converted to the value stored in the 5120 // designated object (and is no longer an lvalue). 5121 if (E->isRValue()) { 5122 // In C, function designators (i.e. expressions of function type) 5123 // are r-values, but we still want to do function-to-pointer decay 5124 // on them. This is both technically correct and convenient for 5125 // some clients. 5126 if (!getLangOptions().CPlusPlus && E->getType()->isFunctionType()) 5127 return DefaultFunctionArrayConversion(E); 5128 5129 return Owned(E); 5130 } 5131 5132 // Otherwise, this rule does not apply in C++, at least not for the moment. 5133 if (getLangOptions().CPlusPlus) return Owned(E); 5134 5135 // GCC seems to also exclude expressions of incomplete enum type. 5136 if (const EnumType *T = E->getType()->getAs<EnumType>()) { 5137 if (!T->getDecl()->isComplete()) { 5138 // FIXME: stupid workaround for a codegen bug! 5139 E = ImpCastExprToType(E, Context.VoidTy, CK_ToVoid).take(); 5140 return Owned(E); 5141 } 5142 } 5143 5144 ExprResult Res = DefaultFunctionArrayLvalueConversion(E); 5145 if (Res.isInvalid()) 5146 return Owned(E); 5147 E = Res.take(); 5148 5149 if (!E->getType()->isVoidType()) 5150 RequireCompleteType(E->getExprLoc(), E->getType(), 5151 diag::err_incomplete_type); 5152 return Owned(E); 5153} 5154 5155ExprResult Sema::ActOnFinishFullExpr(Expr *FE) { 5156 ExprResult FullExpr = Owned(FE); 5157 5158 if (!FullExpr.get()) 5159 return ExprError(); 5160 5161 if (DiagnoseUnexpandedParameterPack(FullExpr.get())) 5162 return ExprError(); 5163 5164 // Top-level message sends default to 'id' when we're in a debugger. 5165 if (getLangOptions().DebuggerCastResultToId && 5166 FullExpr.get()->getType() == Context.UnknownAnyTy && 5167 isa<ObjCMessageExpr>(FullExpr.get())) { 5168 FullExpr = forceUnknownAnyToType(FullExpr.take(), Context.getObjCIdType()); 5169 if (FullExpr.isInvalid()) 5170 return ExprError(); 5171 } 5172 5173 FullExpr = CheckPlaceholderExpr(FullExpr.take()); 5174 if (FullExpr.isInvalid()) 5175 return ExprError(); 5176 5177 FullExpr = IgnoredValueConversions(FullExpr.take()); 5178 if (FullExpr.isInvalid()) 5179 return ExprError(); 5180 5181 CheckImplicitConversions(FullExpr.get(), FullExpr.get()->getExprLoc()); 5182 return MaybeCreateExprWithCleanups(FullExpr); 5183} 5184 5185StmtResult Sema::ActOnFinishFullStmt(Stmt *FullStmt) { 5186 if (!FullStmt) return StmtError(); 5187 5188 return MaybeCreateStmtWithCleanups(FullStmt); 5189} 5190 5191Sema::IfExistsResult 5192Sema::CheckMicrosoftIfExistsSymbol(Scope *S, 5193 CXXScopeSpec &SS, 5194 const DeclarationNameInfo &TargetNameInfo) { 5195 DeclarationName TargetName = TargetNameInfo.getName(); 5196 if (!TargetName) 5197 return IER_DoesNotExist; 5198 5199 // If the name itself is dependent, then the result is dependent. 5200 if (TargetName.isDependentName()) 5201 return IER_Dependent; 5202 5203 // Do the redeclaration lookup in the current scope. 5204 LookupResult R(*this, TargetNameInfo, Sema::LookupAnyName, 5205 Sema::NotForRedeclaration); 5206 LookupParsedName(R, S, &SS); 5207 R.suppressDiagnostics(); 5208 5209 switch (R.getResultKind()) { 5210 case LookupResult::Found: 5211 case LookupResult::FoundOverloaded: 5212 case LookupResult::FoundUnresolvedValue: 5213 case LookupResult::Ambiguous: 5214 return IER_Exists; 5215 5216 case LookupResult::NotFound: 5217 return IER_DoesNotExist; 5218 5219 case LookupResult::NotFoundInCurrentInstantiation: 5220 return IER_Dependent; 5221 } 5222 5223 llvm_unreachable("Invalid LookupResult Kind!"); 5224} 5225 5226Sema::IfExistsResult 5227Sema::CheckMicrosoftIfExistsSymbol(Scope *S, SourceLocation KeywordLoc, 5228 bool IsIfExists, CXXScopeSpec &SS, 5229 UnqualifiedId &Name) { 5230 DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name); 5231 5232 // Check for unexpanded parameter packs. 5233 SmallVector<UnexpandedParameterPack, 4> Unexpanded; 5234 collectUnexpandedParameterPacks(SS, Unexpanded); 5235 collectUnexpandedParameterPacks(TargetNameInfo, Unexpanded); 5236 if (!Unexpanded.empty()) { 5237 DiagnoseUnexpandedParameterPacks(KeywordLoc, 5238 IsIfExists? UPPC_IfExists 5239 : UPPC_IfNotExists, 5240 Unexpanded); 5241 return IER_Error; 5242 } 5243 5244 return CheckMicrosoftIfExistsSymbol(S, SS, TargetNameInfo); 5245} 5246