SemaExprCXX.cpp revision 9583fa752f1d32c68daca069fb8dd34e0aa80478
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 "SemaInherit.h" 15#include "Sema.h" 16#include "clang/AST/ExprCXX.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/Parse/DeclSpec.h" 19#include "clang/Lex/Preprocessor.h" 20#include "clang/Basic/TargetInfo.h" 21#include "llvm/ADT/STLExtras.h" 22using namespace clang; 23 24/// ActOnCXXConversionFunctionExpr - Parse a C++ conversion function 25/// name (e.g., operator void const *) as an expression. This is 26/// very similar to ActOnIdentifierExpr, except that instead of 27/// providing an identifier the parser provides the type of the 28/// conversion function. 29Sema::OwningExprResult 30Sema::ActOnCXXConversionFunctionExpr(Scope *S, SourceLocation OperatorLoc, 31 TypeTy *Ty, bool HasTrailingLParen, 32 const CXXScopeSpec &SS, 33 bool isAddressOfOperand) { 34 QualType ConvType = QualType::getFromOpaquePtr(Ty); 35 CanQualType ConvTypeCanon = Context.getCanonicalType(ConvType); 36 DeclarationName ConvName 37 = Context.DeclarationNames.getCXXConversionFunctionName(ConvTypeCanon); 38 return ActOnDeclarationNameExpr(S, OperatorLoc, ConvName, HasTrailingLParen, 39 &SS, isAddressOfOperand); 40} 41 42/// ActOnCXXOperatorFunctionIdExpr - Parse a C++ overloaded operator 43/// name (e.g., @c operator+ ) as an expression. This is very 44/// similar to ActOnIdentifierExpr, except that instead of providing 45/// an identifier the parser provides the kind of overloaded 46/// operator that was parsed. 47Sema::OwningExprResult 48Sema::ActOnCXXOperatorFunctionIdExpr(Scope *S, SourceLocation OperatorLoc, 49 OverloadedOperatorKind Op, 50 bool HasTrailingLParen, 51 const CXXScopeSpec &SS, 52 bool isAddressOfOperand) { 53 DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(Op); 54 return ActOnDeclarationNameExpr(S, OperatorLoc, Name, HasTrailingLParen, &SS, 55 isAddressOfOperand); 56} 57 58/// ActOnCXXTypeidOfType - Parse typeid( type-id ). 59Action::OwningExprResult 60Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc, 61 bool isType, void *TyOrExpr, SourceLocation RParenLoc) { 62 NamespaceDecl *StdNs = GetStdNamespace(); 63 if (!StdNs) 64 return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid)); 65 66 IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info"); 67 Decl *TypeInfoDecl = LookupQualifiedName(StdNs, TypeInfoII, LookupTagName); 68 RecordDecl *TypeInfoRecordDecl = dyn_cast_or_null<RecordDecl>(TypeInfoDecl); 69 if (!TypeInfoRecordDecl) 70 return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid)); 71 72 QualType TypeInfoType = Context.getTypeDeclType(TypeInfoRecordDecl); 73 74 if (!isType) { 75 // C++0x [expr.typeid]p3: 76 // When typeid is applied to an expression other than an lvalue of a 77 // polymorphic class type [...] [the] expression is an unevaluated 78 // operand. 79 80 // FIXME: if the type of the expression is a class type, the class 81 // shall be completely defined. 82 bool isUnevaluatedOperand = true; 83 Expr *E = static_cast<Expr *>(TyOrExpr); 84 if (E && !E->isTypeDependent() && E->isLvalue(Context) == Expr::LV_Valid) { 85 QualType T = E->getType(); 86 if (const RecordType *RecordT = T->getAs<RecordType>()) { 87 CXXRecordDecl *RecordD = cast<CXXRecordDecl>(RecordT->getDecl()); 88 if (RecordD->isPolymorphic()) 89 isUnevaluatedOperand = false; 90 } 91 } 92 93 // If this is an unevaluated operand, clear out the set of declaration 94 // references we have been computing. 95 if (isUnevaluatedOperand) 96 PotentiallyReferencedDeclStack.back().clear(); 97 } 98 99 return Owned(new (Context) CXXTypeidExpr(isType, TyOrExpr, 100 TypeInfoType.withConst(), 101 SourceRange(OpLoc, RParenLoc))); 102} 103 104/// ActOnCXXBoolLiteral - Parse {true,false} literals. 105Action::OwningExprResult 106Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) { 107 assert((Kind == tok::kw_true || Kind == tok::kw_false) && 108 "Unknown C++ Boolean value!"); 109 return Owned(new (Context) CXXBoolLiteralExpr(Kind == tok::kw_true, 110 Context.BoolTy, OpLoc)); 111} 112 113/// ActOnCXXNullPtrLiteral - Parse 'nullptr'. 114Action::OwningExprResult 115Sema::ActOnCXXNullPtrLiteral(SourceLocation Loc) { 116 return Owned(new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc)); 117} 118 119/// ActOnCXXThrow - Parse throw expressions. 120Action::OwningExprResult 121Sema::ActOnCXXThrow(SourceLocation OpLoc, ExprArg E) { 122 Expr *Ex = E.takeAs<Expr>(); 123 if (Ex && !Ex->isTypeDependent() && CheckCXXThrowOperand(OpLoc, Ex)) 124 return ExprError(); 125 return Owned(new (Context) CXXThrowExpr(Ex, Context.VoidTy, OpLoc)); 126} 127 128/// CheckCXXThrowOperand - Validate the operand of a throw. 129bool Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc, Expr *&E) { 130 // C++ [except.throw]p3: 131 // [...] adjusting the type from "array of T" or "function returning T" 132 // to "pointer to T" or "pointer to function returning T", [...] 133 DefaultFunctionArrayConversion(E); 134 135 // If the type of the exception would be an incomplete type or a pointer 136 // to an incomplete type other than (cv) void the program is ill-formed. 137 QualType Ty = E->getType(); 138 int isPointer = 0; 139 if (const PointerType* Ptr = Ty->getAs<PointerType>()) { 140 Ty = Ptr->getPointeeType(); 141 isPointer = 1; 142 } 143 if (!isPointer || !Ty->isVoidType()) { 144 if (RequireCompleteType(ThrowLoc, Ty, 145 isPointer ? diag::err_throw_incomplete_ptr 146 : diag::err_throw_incomplete, 147 E->getSourceRange(), SourceRange(), QualType())) 148 return true; 149 } 150 151 // FIXME: Construct a temporary here. 152 return false; 153} 154 155Action::OwningExprResult Sema::ActOnCXXThis(SourceLocation ThisLoc) { 156 /// C++ 9.3.2: In the body of a non-static member function, the keyword this 157 /// is a non-lvalue expression whose value is the address of the object for 158 /// which the function is called. 159 160 if (!isa<FunctionDecl>(CurContext)) 161 return ExprError(Diag(ThisLoc, diag::err_invalid_this_use)); 162 163 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(CurContext)) 164 if (MD->isInstance()) 165 return Owned(new (Context) CXXThisExpr(ThisLoc, 166 MD->getThisType(Context))); 167 168 return ExprError(Diag(ThisLoc, diag::err_invalid_this_use)); 169} 170 171/// ActOnCXXTypeConstructExpr - Parse construction of a specified type. 172/// Can be interpreted either as function-style casting ("int(x)") 173/// or class type construction ("ClassType(x,y,z)") 174/// or creation of a value-initialized type ("int()"). 175Action::OwningExprResult 176Sema::ActOnCXXTypeConstructExpr(SourceRange TypeRange, TypeTy *TypeRep, 177 SourceLocation LParenLoc, 178 MultiExprArg exprs, 179 SourceLocation *CommaLocs, 180 SourceLocation RParenLoc) { 181 assert(TypeRep && "Missing type!"); 182 QualType Ty = QualType::getFromOpaquePtr(TypeRep); 183 unsigned NumExprs = exprs.size(); 184 Expr **Exprs = (Expr**)exprs.get(); 185 SourceLocation TyBeginLoc = TypeRange.getBegin(); 186 SourceRange FullRange = SourceRange(TyBeginLoc, RParenLoc); 187 188 if (Ty->isDependentType() || 189 CallExpr::hasAnyTypeDependentArguments(Exprs, NumExprs)) { 190 exprs.release(); 191 192 return Owned(CXXUnresolvedConstructExpr::Create(Context, 193 TypeRange.getBegin(), Ty, 194 LParenLoc, 195 Exprs, NumExprs, 196 RParenLoc)); 197 } 198 199 200 // C++ [expr.type.conv]p1: 201 // If the expression list is a single expression, the type conversion 202 // expression is equivalent (in definedness, and if defined in meaning) to the 203 // corresponding cast expression. 204 // 205 if (NumExprs == 1) { 206 CastExpr::CastKind Kind = CastExpr::CK_Unknown; 207 if (CheckCastTypes(TypeRange, Ty, Exprs[0], Kind, /*functional-style*/true)) 208 return ExprError(); 209 exprs.release(); 210 return Owned(new (Context) CXXFunctionalCastExpr(Ty.getNonReferenceType(), 211 Ty, TyBeginLoc, Kind, 212 Exprs[0], RParenLoc)); 213 } 214 215 if (const RecordType *RT = Ty->getAs<RecordType>()) { 216 CXXRecordDecl *Record = cast<CXXRecordDecl>(RT->getDecl()); 217 218 // FIXME: We should always create a CXXTemporaryObjectExpr here unless 219 // both the ctor and dtor are trivial. 220 if (NumExprs > 1 || Record->hasUserDeclaredConstructor()) { 221 CXXConstructorDecl *Constructor 222 = PerformInitializationByConstructor(Ty, Exprs, NumExprs, 223 TypeRange.getBegin(), 224 SourceRange(TypeRange.getBegin(), 225 RParenLoc), 226 DeclarationName(), 227 IK_Direct); 228 229 if (!Constructor) 230 return ExprError(); 231 232 exprs.release(); 233 Expr *E = new (Context) CXXTemporaryObjectExpr(Context, Constructor, 234 Ty, TyBeginLoc, Exprs, 235 NumExprs, RParenLoc); 236 return MaybeBindToTemporary(E); 237 } 238 239 // Fall through to value-initialize an object of class type that 240 // doesn't have a user-declared default constructor. 241 } 242 243 // C++ [expr.type.conv]p1: 244 // If the expression list specifies more than a single value, the type shall 245 // be a class with a suitably declared constructor. 246 // 247 if (NumExprs > 1) 248 return ExprError(Diag(CommaLocs[0], 249 diag::err_builtin_func_cast_more_than_one_arg) 250 << FullRange); 251 252 assert(NumExprs == 0 && "Expected 0 expressions"); 253 254 // C++ [expr.type.conv]p2: 255 // The expression T(), where T is a simple-type-specifier for a non-array 256 // complete object type or the (possibly cv-qualified) void type, creates an 257 // rvalue of the specified type, which is value-initialized. 258 // 259 if (Ty->isArrayType()) 260 return ExprError(Diag(TyBeginLoc, 261 diag::err_value_init_for_array_type) << FullRange); 262 if (!Ty->isDependentType() && !Ty->isVoidType() && 263 RequireCompleteType(TyBeginLoc, Ty, 264 diag::err_invalid_incomplete_type_use, FullRange)) 265 return ExprError(); 266 267 if (RequireNonAbstractType(TyBeginLoc, Ty, 268 diag::err_allocation_of_abstract_type)) 269 return ExprError(); 270 271 exprs.release(); 272 return Owned(new (Context) CXXZeroInitValueExpr(Ty, TyBeginLoc, RParenLoc)); 273} 274 275 276/// ActOnCXXNew - Parsed a C++ 'new' expression (C++ 5.3.4), as in e.g.: 277/// @code new (memory) int[size][4] @endcode 278/// or 279/// @code ::new Foo(23, "hello") @endcode 280/// For the interpretation of this heap of arguments, consult the base version. 281Action::OwningExprResult 282Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal, 283 SourceLocation PlacementLParen, MultiExprArg PlacementArgs, 284 SourceLocation PlacementRParen, bool ParenTypeId, 285 Declarator &D, SourceLocation ConstructorLParen, 286 MultiExprArg ConstructorArgs, 287 SourceLocation ConstructorRParen) 288{ 289 Expr *ArraySize = 0; 290 unsigned Skip = 0; 291 // If the specified type is an array, unwrap it and save the expression. 292 if (D.getNumTypeObjects() > 0 && 293 D.getTypeObject(0).Kind == DeclaratorChunk::Array) { 294 DeclaratorChunk &Chunk = D.getTypeObject(0); 295 if (Chunk.Arr.hasStatic) 296 return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new) 297 << D.getSourceRange()); 298 if (!Chunk.Arr.NumElts) 299 return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size) 300 << D.getSourceRange()); 301 ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts); 302 Skip = 1; 303 } 304 305 QualType AllocType = GetTypeForDeclarator(D, /*Scope=*/0, Skip); 306 if (D.isInvalidType()) 307 return ExprError(); 308 309 // Every dimension shall be of constant size. 310 unsigned i = 1; 311 QualType ElementType = AllocType; 312 while (const ArrayType *Array = Context.getAsArrayType(ElementType)) { 313 if (!Array->isConstantArrayType()) { 314 Diag(D.getTypeObject(i).Loc, diag::err_new_array_nonconst) 315 << static_cast<Expr*>(D.getTypeObject(i).Arr.NumElts)->getSourceRange(); 316 return ExprError(); 317 } 318 ElementType = Array->getElementType(); 319 ++i; 320 } 321 322 return BuildCXXNew(StartLoc, UseGlobal, 323 PlacementLParen, 324 move(PlacementArgs), 325 PlacementRParen, 326 ParenTypeId, 327 AllocType, 328 D.getSourceRange().getBegin(), 329 D.getSourceRange(), 330 Owned(ArraySize), 331 ConstructorLParen, 332 move(ConstructorArgs), 333 ConstructorRParen); 334} 335 336Sema::OwningExprResult 337Sema::BuildCXXNew(SourceLocation StartLoc, bool UseGlobal, 338 SourceLocation PlacementLParen, 339 MultiExprArg PlacementArgs, 340 SourceLocation PlacementRParen, 341 bool ParenTypeId, 342 QualType AllocType, 343 SourceLocation TypeLoc, 344 SourceRange TypeRange, 345 ExprArg ArraySizeE, 346 SourceLocation ConstructorLParen, 347 MultiExprArg ConstructorArgs, 348 SourceLocation ConstructorRParen) { 349 if (CheckAllocatedType(AllocType, TypeLoc, TypeRange)) 350 return ExprError(); 351 352 QualType ResultType = Context.getPointerType(AllocType); 353 354 // That every array dimension except the first is constant was already 355 // checked by the type check above. 356 357 // C++ 5.3.4p6: "The expression in a direct-new-declarator shall have integral 358 // or enumeration type with a non-negative value." 359 Expr *ArraySize = (Expr *)ArraySizeE.get(); 360 if (ArraySize && !ArraySize->isTypeDependent()) { 361 QualType SizeType = ArraySize->getType(); 362 if (!SizeType->isIntegralType() && !SizeType->isEnumeralType()) 363 return ExprError(Diag(ArraySize->getSourceRange().getBegin(), 364 diag::err_array_size_not_integral) 365 << SizeType << ArraySize->getSourceRange()); 366 // Let's see if this is a constant < 0. If so, we reject it out of hand. 367 // We don't care about special rules, so we tell the machinery it's not 368 // evaluated - it gives us a result in more cases. 369 if (!ArraySize->isValueDependent()) { 370 llvm::APSInt Value; 371 if (ArraySize->isIntegerConstantExpr(Value, Context, 0, false)) { 372 if (Value < llvm::APSInt( 373 llvm::APInt::getNullValue(Value.getBitWidth()), false)) 374 return ExprError(Diag(ArraySize->getSourceRange().getBegin(), 375 diag::err_typecheck_negative_array_size) 376 << ArraySize->getSourceRange()); 377 } 378 } 379 } 380 381 FunctionDecl *OperatorNew = 0; 382 FunctionDecl *OperatorDelete = 0; 383 Expr **PlaceArgs = (Expr**)PlacementArgs.get(); 384 unsigned NumPlaceArgs = PlacementArgs.size(); 385 if (!AllocType->isDependentType() && 386 !Expr::hasAnyTypeDependentArguments(PlaceArgs, NumPlaceArgs) && 387 FindAllocationFunctions(StartLoc, 388 SourceRange(PlacementLParen, PlacementRParen), 389 UseGlobal, AllocType, ArraySize, PlaceArgs, 390 NumPlaceArgs, OperatorNew, OperatorDelete)) 391 return ExprError(); 392 393 bool Init = ConstructorLParen.isValid(); 394 // --- Choosing a constructor --- 395 // C++ 5.3.4p15 396 // 1) If T is a POD and there's no initializer (ConstructorLParen is invalid) 397 // the object is not initialized. If the object, or any part of it, is 398 // const-qualified, it's an error. 399 // 2) If T is a POD and there's an empty initializer, the object is value- 400 // initialized. 401 // 3) If T is a POD and there's one initializer argument, the object is copy- 402 // constructed. 403 // 4) If T is a POD and there's more initializer arguments, it's an error. 404 // 5) If T is not a POD, the initializer arguments are used as constructor 405 // arguments. 406 // 407 // Or by the C++0x formulation: 408 // 1) If there's no initializer, the object is default-initialized according 409 // to C++0x rules. 410 // 2) Otherwise, the object is direct-initialized. 411 CXXConstructorDecl *Constructor = 0; 412 Expr **ConsArgs = (Expr**)ConstructorArgs.get(); 413 const RecordType *RT; 414 unsigned NumConsArgs = ConstructorArgs.size(); 415 if (AllocType->isDependentType()) { 416 // Skip all the checks. 417 } else if ((RT = AllocType->getAs<RecordType>()) && 418 !AllocType->isAggregateType()) { 419 Constructor = PerformInitializationByConstructor( 420 AllocType, ConsArgs, NumConsArgs, 421 TypeLoc, 422 SourceRange(TypeLoc, ConstructorRParen), 423 RT->getDecl()->getDeclName(), 424 NumConsArgs != 0 ? IK_Direct : IK_Default); 425 if (!Constructor) 426 return ExprError(); 427 } else { 428 if (!Init) { 429 // FIXME: Check that no subpart is const. 430 if (AllocType.isConstQualified()) 431 return ExprError(Diag(StartLoc, diag::err_new_uninitialized_const) 432 << TypeRange); 433 } else if (NumConsArgs == 0) { 434 // Object is value-initialized. Do nothing. 435 } else if (NumConsArgs == 1) { 436 // Object is direct-initialized. 437 // FIXME: What DeclarationName do we pass in here? 438 if (CheckInitializerTypes(ConsArgs[0], AllocType, StartLoc, 439 DeclarationName() /*AllocType.getAsString()*/, 440 /*DirectInit=*/true)) 441 return ExprError(); 442 } else { 443 return ExprError(Diag(StartLoc, 444 diag::err_builtin_direct_init_more_than_one_arg) 445 << SourceRange(ConstructorLParen, ConstructorRParen)); 446 } 447 } 448 449 // FIXME: Also check that the destructor is accessible. (C++ 5.3.4p16) 450 451 PlacementArgs.release(); 452 ConstructorArgs.release(); 453 ArraySizeE.release(); 454 return Owned(new (Context) CXXNewExpr(UseGlobal, OperatorNew, PlaceArgs, 455 NumPlaceArgs, ParenTypeId, ArraySize, Constructor, Init, 456 ConsArgs, NumConsArgs, OperatorDelete, ResultType, 457 StartLoc, Init ? ConstructorRParen : SourceLocation())); 458} 459 460/// CheckAllocatedType - Checks that a type is suitable as the allocated type 461/// in a new-expression. 462/// dimension off and stores the size expression in ArraySize. 463bool Sema::CheckAllocatedType(QualType AllocType, SourceLocation Loc, 464 SourceRange R) 465{ 466 // C++ 5.3.4p1: "[The] type shall be a complete object type, but not an 467 // abstract class type or array thereof. 468 if (AllocType->isFunctionType()) 469 return Diag(Loc, diag::err_bad_new_type) 470 << AllocType << 0 << R; 471 else if (AllocType->isReferenceType()) 472 return Diag(Loc, diag::err_bad_new_type) 473 << AllocType << 1 << R; 474 else if (!AllocType->isDependentType() && 475 RequireCompleteType(Loc, AllocType, 476 diag::err_new_incomplete_type, 477 R)) 478 return true; 479 else if (RequireNonAbstractType(Loc, AllocType, 480 diag::err_allocation_of_abstract_type)) 481 return true; 482 483 return false; 484} 485 486/// FindAllocationFunctions - Finds the overloads of operator new and delete 487/// that are appropriate for the allocation. 488bool Sema::FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range, 489 bool UseGlobal, QualType AllocType, 490 bool IsArray, Expr **PlaceArgs, 491 unsigned NumPlaceArgs, 492 FunctionDecl *&OperatorNew, 493 FunctionDecl *&OperatorDelete) 494{ 495 // --- Choosing an allocation function --- 496 // C++ 5.3.4p8 - 14 & 18 497 // 1) If UseGlobal is true, only look in the global scope. Else, also look 498 // in the scope of the allocated class. 499 // 2) If an array size is given, look for operator new[], else look for 500 // operator new. 501 // 3) The first argument is always size_t. Append the arguments from the 502 // placement form. 503 // FIXME: Also find the appropriate delete operator. 504 505 llvm::SmallVector<Expr*, 8> AllocArgs(1 + NumPlaceArgs); 506 // We don't care about the actual value of this argument. 507 // FIXME: Should the Sema create the expression and embed it in the syntax 508 // tree? Or should the consumer just recalculate the value? 509 AllocArgs[0] = new (Context) IntegerLiteral(llvm::APInt::getNullValue( 510 Context.Target.getPointerWidth(0)), 511 Context.getSizeType(), 512 SourceLocation()); 513 std::copy(PlaceArgs, PlaceArgs + NumPlaceArgs, AllocArgs.begin() + 1); 514 515 DeclarationName NewName = Context.DeclarationNames.getCXXOperatorName( 516 IsArray ? OO_Array_New : OO_New); 517 if (AllocType->isRecordType() && !UseGlobal) { 518 CXXRecordDecl *Record 519 = cast<CXXRecordDecl>(AllocType->getAs<RecordType>()->getDecl()); 520 // FIXME: We fail to find inherited overloads. 521 if (FindAllocationOverload(StartLoc, Range, NewName, &AllocArgs[0], 522 AllocArgs.size(), Record, /*AllowMissing=*/true, 523 OperatorNew)) 524 return true; 525 } 526 if (!OperatorNew) { 527 // Didn't find a member overload. Look for a global one. 528 DeclareGlobalNewDelete(); 529 DeclContext *TUDecl = Context.getTranslationUnitDecl(); 530 if (FindAllocationOverload(StartLoc, Range, NewName, &AllocArgs[0], 531 AllocArgs.size(), TUDecl, /*AllowMissing=*/false, 532 OperatorNew)) 533 return true; 534 } 535 536 // FindAllocationOverload can change the passed in arguments, so we need to 537 // copy them back. 538 if (NumPlaceArgs > 0) 539 std::copy(&AllocArgs[1], AllocArgs.end(), PlaceArgs); 540 541 // FIXME: This is leaked on error. But so much is currently in Sema that it's 542 // easier to clean it in one go. 543 AllocArgs[0]->Destroy(Context); 544 return false; 545} 546 547/// FindAllocationOverload - Find an fitting overload for the allocation 548/// function in the specified scope. 549bool Sema::FindAllocationOverload(SourceLocation StartLoc, SourceRange Range, 550 DeclarationName Name, Expr** Args, 551 unsigned NumArgs, DeclContext *Ctx, 552 bool AllowMissing, FunctionDecl *&Operator) 553{ 554 DeclContext::lookup_iterator Alloc, AllocEnd; 555 llvm::tie(Alloc, AllocEnd) = Ctx->lookup(Name); 556 if (Alloc == AllocEnd) { 557 if (AllowMissing) 558 return false; 559 return Diag(StartLoc, diag::err_ovl_no_viable_function_in_call) 560 << Name << Range; 561 } 562 563 OverloadCandidateSet Candidates; 564 for (; Alloc != AllocEnd; ++Alloc) { 565 // Even member operator new/delete are implicitly treated as 566 // static, so don't use AddMemberCandidate. 567 if (FunctionDecl *Fn = dyn_cast<FunctionDecl>(*Alloc)) 568 AddOverloadCandidate(Fn, Args, NumArgs, Candidates, 569 /*SuppressUserConversions=*/false); 570 } 571 572 // Do the resolution. 573 OverloadCandidateSet::iterator Best; 574 switch(BestViableFunction(Candidates, StartLoc, Best)) { 575 case OR_Success: { 576 // Got one! 577 FunctionDecl *FnDecl = Best->Function; 578 // The first argument is size_t, and the first parameter must be size_t, 579 // too. This is checked on declaration and can be assumed. (It can't be 580 // asserted on, though, since invalid decls are left in there.) 581 for (unsigned i = 1; i < NumArgs; ++i) { 582 // FIXME: Passing word to diagnostic. 583 if (PerformCopyInitialization(Args[i], 584 FnDecl->getParamDecl(i)->getType(), 585 "passing")) 586 return true; 587 } 588 Operator = FnDecl; 589 return false; 590 } 591 592 case OR_No_Viable_Function: 593 Diag(StartLoc, diag::err_ovl_no_viable_function_in_call) 594 << Name << Range; 595 PrintOverloadCandidates(Candidates, /*OnlyViable=*/false); 596 return true; 597 598 case OR_Ambiguous: 599 Diag(StartLoc, diag::err_ovl_ambiguous_call) 600 << Name << Range; 601 PrintOverloadCandidates(Candidates, /*OnlyViable=*/true); 602 return true; 603 604 case OR_Deleted: 605 Diag(StartLoc, diag::err_ovl_deleted_call) 606 << Best->Function->isDeleted() 607 << Name << Range; 608 PrintOverloadCandidates(Candidates, /*OnlyViable=*/true); 609 return true; 610 } 611 assert(false && "Unreachable, bad result from BestViableFunction"); 612 return true; 613} 614 615 616/// DeclareGlobalNewDelete - Declare the global forms of operator new and 617/// delete. These are: 618/// @code 619/// void* operator new(std::size_t) throw(std::bad_alloc); 620/// void* operator new[](std::size_t) throw(std::bad_alloc); 621/// void operator delete(void *) throw(); 622/// void operator delete[](void *) throw(); 623/// @endcode 624/// Note that the placement and nothrow forms of new are *not* implicitly 625/// declared. Their use requires including \<new\>. 626void Sema::DeclareGlobalNewDelete() 627{ 628 if (GlobalNewDeleteDeclared) 629 return; 630 GlobalNewDeleteDeclared = true; 631 632 QualType VoidPtr = Context.getPointerType(Context.VoidTy); 633 QualType SizeT = Context.getSizeType(); 634 635 // FIXME: Exception specifications are not added. 636 DeclareGlobalAllocationFunction( 637 Context.DeclarationNames.getCXXOperatorName(OO_New), 638 VoidPtr, SizeT); 639 DeclareGlobalAllocationFunction( 640 Context.DeclarationNames.getCXXOperatorName(OO_Array_New), 641 VoidPtr, SizeT); 642 DeclareGlobalAllocationFunction( 643 Context.DeclarationNames.getCXXOperatorName(OO_Delete), 644 Context.VoidTy, VoidPtr); 645 DeclareGlobalAllocationFunction( 646 Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete), 647 Context.VoidTy, VoidPtr); 648} 649 650/// DeclareGlobalAllocationFunction - Declares a single implicit global 651/// allocation function if it doesn't already exist. 652void Sema::DeclareGlobalAllocationFunction(DeclarationName Name, 653 QualType Return, QualType Argument) 654{ 655 DeclContext *GlobalCtx = Context.getTranslationUnitDecl(); 656 657 // Check if this function is already declared. 658 { 659 DeclContext::lookup_iterator Alloc, AllocEnd; 660 for (llvm::tie(Alloc, AllocEnd) = GlobalCtx->lookup(Name); 661 Alloc != AllocEnd; ++Alloc) { 662 // FIXME: Do we need to check for default arguments here? 663 FunctionDecl *Func = cast<FunctionDecl>(*Alloc); 664 if (Func->getNumParams() == 1 && 665 Context.getCanonicalType(Func->getParamDecl(0)->getType())==Argument) 666 return; 667 } 668 } 669 670 QualType FnType = Context.getFunctionType(Return, &Argument, 1, false, 0); 671 FunctionDecl *Alloc = 672 FunctionDecl::Create(Context, GlobalCtx, SourceLocation(), Name, 673 FnType, FunctionDecl::None, false, true, 674 SourceLocation()); 675 Alloc->setImplicit(); 676 ParmVarDecl *Param = ParmVarDecl::Create(Context, Alloc, SourceLocation(), 677 0, Argument, VarDecl::None, 0); 678 Alloc->setParams(Context, &Param, 1); 679 680 // FIXME: Also add this declaration to the IdentifierResolver, but 681 // make sure it is at the end of the chain to coincide with the 682 // global scope. 683 ((DeclContext *)TUScope->getEntity())->addDecl(Alloc); 684} 685 686/// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in: 687/// @code ::delete ptr; @endcode 688/// or 689/// @code delete [] ptr; @endcode 690Action::OwningExprResult 691Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal, 692 bool ArrayForm, ExprArg Operand) 693{ 694 // C++ 5.3.5p1: "The operand shall have a pointer type, or a class type 695 // having a single conversion function to a pointer type. The result has 696 // type void." 697 // DR599 amends "pointer type" to "pointer to object type" in both cases. 698 699 Expr *Ex = (Expr *)Operand.get(); 700 if (!Ex->isTypeDependent()) { 701 QualType Type = Ex->getType(); 702 703 if (Type->isRecordType()) { 704 // FIXME: Find that one conversion function and amend the type. 705 } 706 707 if (!Type->isPointerType()) 708 return ExprError(Diag(StartLoc, diag::err_delete_operand) 709 << Type << Ex->getSourceRange()); 710 711 QualType Pointee = Type->getAs<PointerType>()->getPointeeType(); 712 if (Pointee->isFunctionType() || Pointee->isVoidType()) 713 return ExprError(Diag(StartLoc, diag::err_delete_operand) 714 << Type << Ex->getSourceRange()); 715 else if (!Pointee->isDependentType() && 716 RequireCompleteType(StartLoc, Pointee, 717 diag::warn_delete_incomplete, 718 Ex->getSourceRange())) 719 return ExprError(); 720 721 // FIXME: Look up the correct operator delete overload and pass a pointer 722 // along. 723 // FIXME: Check access and ambiguity of operator delete and destructor. 724 } 725 726 Operand.release(); 727 return Owned(new (Context) CXXDeleteExpr(Context.VoidTy, UseGlobal, ArrayForm, 728 0, Ex, StartLoc)); 729} 730 731 732/// ActOnCXXConditionDeclarationExpr - Parsed a condition declaration of a 733/// C++ if/switch/while/for statement. 734/// e.g: "if (int x = f()) {...}" 735Action::OwningExprResult 736Sema::ActOnCXXConditionDeclarationExpr(Scope *S, SourceLocation StartLoc, 737 Declarator &D, 738 SourceLocation EqualLoc, 739 ExprArg AssignExprVal) { 740 assert(AssignExprVal.get() && "Null assignment expression"); 741 742 // C++ 6.4p2: 743 // The declarator shall not specify a function or an array. 744 // The type-specifier-seq shall not contain typedef and shall not declare a 745 // new class or enumeration. 746 747 assert(D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef && 748 "Parser allowed 'typedef' as storage class of condition decl."); 749 750 QualType Ty = GetTypeForDeclarator(D, S); 751 752 if (Ty->isFunctionType()) { // The declarator shall not specify a function... 753 // We exit without creating a CXXConditionDeclExpr because a FunctionDecl 754 // would be created and CXXConditionDeclExpr wants a VarDecl. 755 return ExprError(Diag(StartLoc, diag::err_invalid_use_of_function_type) 756 << SourceRange(StartLoc, EqualLoc)); 757 } else if (Ty->isArrayType()) { // ...or an array. 758 Diag(StartLoc, diag::err_invalid_use_of_array_type) 759 << SourceRange(StartLoc, EqualLoc); 760 } else if (const RecordType *RT = Ty->getAs<RecordType>()) { 761 RecordDecl *RD = RT->getDecl(); 762 // The type-specifier-seq shall not declare a new class... 763 if (RD->isDefinition() && 764 (RD->getIdentifier() == 0 || S->isDeclScope(DeclPtrTy::make(RD)))) 765 Diag(RD->getLocation(), diag::err_type_defined_in_condition); 766 } else if (const EnumType *ET = Ty->getAsEnumType()) { 767 EnumDecl *ED = ET->getDecl(); 768 // ...or enumeration. 769 if (ED->isDefinition() && 770 (ED->getIdentifier() == 0 || S->isDeclScope(DeclPtrTy::make(ED)))) 771 Diag(ED->getLocation(), diag::err_type_defined_in_condition); 772 } 773 774 DeclPtrTy Dcl = ActOnDeclarator(S, D); 775 if (!Dcl) 776 return ExprError(); 777 AddInitializerToDecl(Dcl, move(AssignExprVal), /*DirectInit=*/false); 778 779 // Mark this variable as one that is declared within a conditional. 780 // We know that the decl had to be a VarDecl because that is the only type of 781 // decl that can be assigned and the grammar requires an '='. 782 VarDecl *VD = cast<VarDecl>(Dcl.getAs<Decl>()); 783 VD->setDeclaredInCondition(true); 784 return Owned(new (Context) CXXConditionDeclExpr(StartLoc, EqualLoc, VD)); 785} 786 787/// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid. 788bool Sema::CheckCXXBooleanCondition(Expr *&CondExpr) { 789 // C++ 6.4p4: 790 // The value of a condition that is an initialized declaration in a statement 791 // other than a switch statement is the value of the declared variable 792 // implicitly converted to type bool. If that conversion is ill-formed, the 793 // program is ill-formed. 794 // The value of a condition that is an expression is the value of the 795 // expression, implicitly converted to bool. 796 // 797 return PerformContextuallyConvertToBool(CondExpr); 798} 799 800/// Helper function to determine whether this is the (deprecated) C++ 801/// conversion from a string literal to a pointer to non-const char or 802/// non-const wchar_t (for narrow and wide string literals, 803/// respectively). 804bool 805Sema::IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType) { 806 // Look inside the implicit cast, if it exists. 807 if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From)) 808 From = Cast->getSubExpr(); 809 810 // A string literal (2.13.4) that is not a wide string literal can 811 // be converted to an rvalue of type "pointer to char"; a wide 812 // string literal can be converted to an rvalue of type "pointer 813 // to wchar_t" (C++ 4.2p2). 814 if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From)) 815 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) 816 if (const BuiltinType *ToPointeeType 817 = ToPtrType->getPointeeType()->getAsBuiltinType()) { 818 // This conversion is considered only when there is an 819 // explicit appropriate pointer target type (C++ 4.2p2). 820 if (ToPtrType->getPointeeType().getCVRQualifiers() == 0 && 821 ((StrLit->isWide() && ToPointeeType->isWideCharType()) || 822 (!StrLit->isWide() && 823 (ToPointeeType->getKind() == BuiltinType::Char_U || 824 ToPointeeType->getKind() == BuiltinType::Char_S)))) 825 return true; 826 } 827 828 return false; 829} 830 831/// PerformImplicitConversion - Perform an implicit conversion of the 832/// expression From to the type ToType. Returns true if there was an 833/// error, false otherwise. The expression From is replaced with the 834/// converted expression. Flavor is the kind of conversion we're 835/// performing, used in the error message. If @p AllowExplicit, 836/// explicit user-defined conversions are permitted. @p Elidable should be true 837/// when called for copies which may be elided (C++ 12.8p15). C++0x overload 838/// resolution works differently in that case. 839bool 840Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 841 const char *Flavor, bool AllowExplicit, 842 bool Elidable) 843{ 844 ImplicitConversionSequence ICS; 845 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 846 if (Elidable && getLangOptions().CPlusPlus0x) { 847 ICS = TryImplicitConversion(From, ToType, /*SuppressUserConversions*/false, 848 AllowExplicit, /*ForceRValue*/true); 849 } 850 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) { 851 ICS = TryImplicitConversion(From, ToType, false, AllowExplicit); 852 } 853 return PerformImplicitConversion(From, ToType, ICS, Flavor); 854} 855 856/// PerformImplicitConversion - Perform an implicit conversion of the 857/// expression From to the type ToType using the pre-computed implicit 858/// conversion sequence ICS. Returns true if there was an error, false 859/// otherwise. The expression From is replaced with the converted 860/// expression. Flavor is the kind of conversion we're performing, 861/// used in the error message. 862bool 863Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 864 const ImplicitConversionSequence &ICS, 865 const char* Flavor) { 866 switch (ICS.ConversionKind) { 867 case ImplicitConversionSequence::StandardConversion: 868 if (PerformImplicitConversion(From, ToType, ICS.Standard, Flavor)) 869 return true; 870 break; 871 872 case ImplicitConversionSequence::UserDefinedConversion: 873 // FIXME: This is, of course, wrong. We'll need to actually call the 874 // constructor or conversion operator, and then cope with the standard 875 // conversions. 876 ImpCastExprToType(From, ToType.getNonReferenceType(), 877 CastExpr::CK_Unknown, 878 ToType->isLValueReferenceType()); 879 return false; 880 881 case ImplicitConversionSequence::EllipsisConversion: 882 assert(false && "Cannot perform an ellipsis conversion"); 883 return false; 884 885 case ImplicitConversionSequence::BadConversion: 886 return true; 887 } 888 889 // Everything went well. 890 return false; 891} 892 893/// PerformImplicitConversion - Perform an implicit conversion of the 894/// expression From to the type ToType by following the standard 895/// conversion sequence SCS. Returns true if there was an error, false 896/// otherwise. The expression From is replaced with the converted 897/// expression. Flavor is the context in which we're performing this 898/// conversion, for use in error messages. 899bool 900Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 901 const StandardConversionSequence& SCS, 902 const char *Flavor) { 903 // Overall FIXME: we are recomputing too many types here and doing far too 904 // much extra work. What this means is that we need to keep track of more 905 // information that is computed when we try the implicit conversion initially, 906 // so that we don't need to recompute anything here. 907 QualType FromType = From->getType(); 908 909 if (SCS.CopyConstructor) { 910 // FIXME: When can ToType be a reference type? 911 assert(!ToType->isReferenceType()); 912 913 // FIXME: Keep track of whether the copy constructor is elidable or not. 914 bool Elidable = (isa<CallExpr>(From) || 915 isa<CXXTemporaryObjectExpr>(From)); 916 From = BuildCXXConstructExpr(Context, ToType, 917 SCS.CopyConstructor, Elidable, &From, 1); 918 return false; 919 } 920 921 // Perform the first implicit conversion. 922 switch (SCS.First) { 923 case ICK_Identity: 924 case ICK_Lvalue_To_Rvalue: 925 // Nothing to do. 926 break; 927 928 case ICK_Array_To_Pointer: 929 FromType = Context.getArrayDecayedType(FromType); 930 ImpCastExprToType(From, FromType); 931 break; 932 933 case ICK_Function_To_Pointer: 934 if (Context.getCanonicalType(FromType) == Context.OverloadTy) { 935 FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(From, ToType, true); 936 if (!Fn) 937 return true; 938 939 if (DiagnoseUseOfDecl(Fn, From->getSourceRange().getBegin())) 940 return true; 941 942 FixOverloadedFunctionReference(From, Fn); 943 FromType = From->getType(); 944 } 945 FromType = Context.getPointerType(FromType); 946 ImpCastExprToType(From, FromType); 947 break; 948 949 default: 950 assert(false && "Improper first standard conversion"); 951 break; 952 } 953 954 // Perform the second implicit conversion 955 switch (SCS.Second) { 956 case ICK_Identity: 957 // Nothing to do. 958 break; 959 960 case ICK_Integral_Promotion: 961 case ICK_Floating_Promotion: 962 case ICK_Complex_Promotion: 963 case ICK_Integral_Conversion: 964 case ICK_Floating_Conversion: 965 case ICK_Complex_Conversion: 966 case ICK_Floating_Integral: 967 case ICK_Complex_Real: 968 case ICK_Compatible_Conversion: 969 // FIXME: Go deeper to get the unqualified type! 970 FromType = ToType.getUnqualifiedType(); 971 ImpCastExprToType(From, FromType); 972 break; 973 974 case ICK_Pointer_Conversion: 975 if (SCS.IncompatibleObjC) { 976 // Diagnose incompatible Objective-C conversions 977 Diag(From->getSourceRange().getBegin(), 978 diag::ext_typecheck_convert_incompatible_pointer) 979 << From->getType() << ToType << Flavor 980 << From->getSourceRange(); 981 } 982 983 if (CheckPointerConversion(From, ToType)) 984 return true; 985 ImpCastExprToType(From, ToType); 986 break; 987 988 case ICK_Pointer_Member: 989 if (CheckMemberPointerConversion(From, ToType)) 990 return true; 991 ImpCastExprToType(From, ToType); 992 break; 993 994 case ICK_Boolean_Conversion: 995 FromType = Context.BoolTy; 996 ImpCastExprToType(From, FromType); 997 break; 998 999 default: 1000 assert(false && "Improper second standard conversion"); 1001 break; 1002 } 1003 1004 switch (SCS.Third) { 1005 case ICK_Identity: 1006 // Nothing to do. 1007 break; 1008 1009 case ICK_Qualification: 1010 // FIXME: Not sure about lvalue vs rvalue here in the presence of rvalue 1011 // references. 1012 ImpCastExprToType(From, ToType.getNonReferenceType(), 1013 CastExpr::CK_Unknown, 1014 ToType->isLValueReferenceType()); 1015 break; 1016 1017 default: 1018 assert(false && "Improper second standard conversion"); 1019 break; 1020 } 1021 1022 return false; 1023} 1024 1025Sema::OwningExprResult Sema::ActOnUnaryTypeTrait(UnaryTypeTrait OTT, 1026 SourceLocation KWLoc, 1027 SourceLocation LParen, 1028 TypeTy *Ty, 1029 SourceLocation RParen) { 1030 QualType T = QualType::getFromOpaquePtr(Ty); 1031 1032 // According to http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html 1033 // all traits except __is_class, __is_enum and __is_union require a the type 1034 // to be complete. 1035 if (OTT != UTT_IsClass && OTT != UTT_IsEnum && OTT != UTT_IsUnion) { 1036 if (RequireCompleteType(KWLoc, T, 1037 diag::err_incomplete_type_used_in_type_trait_expr, 1038 SourceRange(), SourceRange(), T)) 1039 return ExprError(); 1040 } 1041 1042 // There is no point in eagerly computing the value. The traits are designed 1043 // to be used from type trait templates, so Ty will be a template parameter 1044 // 99% of the time. 1045 return Owned(new (Context) UnaryTypeTraitExpr(KWLoc, OTT, T, 1046 RParen, Context.BoolTy)); 1047} 1048 1049QualType Sema::CheckPointerToMemberOperands( 1050 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isIndirect) 1051{ 1052 const char *OpSpelling = isIndirect ? "->*" : ".*"; 1053 // C++ 5.5p2 1054 // The binary operator .* [p3: ->*] binds its second operand, which shall 1055 // be of type "pointer to member of T" (where T is a completely-defined 1056 // class type) [...] 1057 QualType RType = rex->getType(); 1058 const MemberPointerType *MemPtr = RType->getAs<MemberPointerType>(); 1059 if (!MemPtr) { 1060 Diag(Loc, diag::err_bad_memptr_rhs) 1061 << OpSpelling << RType << rex->getSourceRange(); 1062 return QualType(); 1063 } 1064 1065 QualType Class(MemPtr->getClass(), 0); 1066 1067 // C++ 5.5p2 1068 // [...] to its first operand, which shall be of class T or of a class of 1069 // which T is an unambiguous and accessible base class. [p3: a pointer to 1070 // such a class] 1071 QualType LType = lex->getType(); 1072 if (isIndirect) { 1073 if (const PointerType *Ptr = LType->getAs<PointerType>()) 1074 LType = Ptr->getPointeeType().getNonReferenceType(); 1075 else { 1076 Diag(Loc, diag::err_bad_memptr_lhs) 1077 << OpSpelling << 1 << LType << lex->getSourceRange(); 1078 return QualType(); 1079 } 1080 } 1081 1082 if (Context.getCanonicalType(Class).getUnqualifiedType() != 1083 Context.getCanonicalType(LType).getUnqualifiedType()) { 1084 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1085 /*DetectVirtual=*/false); 1086 // FIXME: Would it be useful to print full ambiguity paths, or is that 1087 // overkill? 1088 if (!IsDerivedFrom(LType, Class, Paths) || 1089 Paths.isAmbiguous(Context.getCanonicalType(Class))) { 1090 Diag(Loc, diag::err_bad_memptr_lhs) << OpSpelling 1091 << (int)isIndirect << lex->getType() << lex->getSourceRange(); 1092 return QualType(); 1093 } 1094 } 1095 1096 // C++ 5.5p2 1097 // The result is an object or a function of the type specified by the 1098 // second operand. 1099 // The cv qualifiers are the union of those in the pointer and the left side, 1100 // in accordance with 5.5p5 and 5.2.5. 1101 // FIXME: This returns a dereferenced member function pointer as a normal 1102 // function type. However, the only operation valid on such functions is 1103 // calling them. There's also a GCC extension to get a function pointer to the 1104 // thing, which is another complication, because this type - unlike the type 1105 // that is the result of this expression - takes the class as the first 1106 // argument. 1107 // We probably need a "MemberFunctionClosureType" or something like that. 1108 QualType Result = MemPtr->getPointeeType(); 1109 if (LType.isConstQualified()) 1110 Result.addConst(); 1111 if (LType.isVolatileQualified()) 1112 Result.addVolatile(); 1113 return Result; 1114} 1115 1116/// \brief Get the target type of a standard or user-defined conversion. 1117static QualType TargetType(const ImplicitConversionSequence &ICS) { 1118 assert((ICS.ConversionKind == 1119 ImplicitConversionSequence::StandardConversion || 1120 ICS.ConversionKind == 1121 ImplicitConversionSequence::UserDefinedConversion) && 1122 "function only valid for standard or user-defined conversions"); 1123 if (ICS.ConversionKind == ImplicitConversionSequence::StandardConversion) 1124 return QualType::getFromOpaquePtr(ICS.Standard.ToTypePtr); 1125 return QualType::getFromOpaquePtr(ICS.UserDefined.After.ToTypePtr); 1126} 1127 1128/// \brief Try to convert a type to another according to C++0x 5.16p3. 1129/// 1130/// This is part of the parameter validation for the ? operator. If either 1131/// value operand is a class type, the two operands are attempted to be 1132/// converted to each other. This function does the conversion in one direction. 1133/// It emits a diagnostic and returns true only if it finds an ambiguous 1134/// conversion. 1135static bool TryClassUnification(Sema &Self, Expr *From, Expr *To, 1136 SourceLocation QuestionLoc, 1137 ImplicitConversionSequence &ICS) 1138{ 1139 // C++0x 5.16p3 1140 // The process for determining whether an operand expression E1 of type T1 1141 // can be converted to match an operand expression E2 of type T2 is defined 1142 // as follows: 1143 // -- If E2 is an lvalue: 1144 if (To->isLvalue(Self.Context) == Expr::LV_Valid) { 1145 // E1 can be converted to match E2 if E1 can be implicitly converted to 1146 // type "lvalue reference to T2", subject to the constraint that in the 1147 // conversion the reference must bind directly to E1. 1148 if (!Self.CheckReferenceInit(From, 1149 Self.Context.getLValueReferenceType(To->getType()), 1150 &ICS)) 1151 { 1152 assert((ICS.ConversionKind == 1153 ImplicitConversionSequence::StandardConversion || 1154 ICS.ConversionKind == 1155 ImplicitConversionSequence::UserDefinedConversion) && 1156 "expected a definite conversion"); 1157 bool DirectBinding = 1158 ICS.ConversionKind == ImplicitConversionSequence::StandardConversion ? 1159 ICS.Standard.DirectBinding : ICS.UserDefined.After.DirectBinding; 1160 if (DirectBinding) 1161 return false; 1162 } 1163 } 1164 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 1165 // -- If E2 is an rvalue, or if the conversion above cannot be done: 1166 // -- if E1 and E2 have class type, and the underlying class types are 1167 // the same or one is a base class of the other: 1168 QualType FTy = From->getType(); 1169 QualType TTy = To->getType(); 1170 const RecordType *FRec = FTy->getAs<RecordType>(); 1171 const RecordType *TRec = TTy->getAs<RecordType>(); 1172 bool FDerivedFromT = FRec && TRec && Self.IsDerivedFrom(FTy, TTy); 1173 if (FRec && TRec && (FRec == TRec || 1174 FDerivedFromT || Self.IsDerivedFrom(TTy, FTy))) { 1175 // E1 can be converted to match E2 if the class of T2 is the 1176 // same type as, or a base class of, the class of T1, and 1177 // [cv2 > cv1]. 1178 if ((FRec == TRec || FDerivedFromT) && TTy.isAtLeastAsQualifiedAs(FTy)) { 1179 // Could still fail if there's no copy constructor. 1180 // FIXME: Is this a hard error then, or just a conversion failure? The 1181 // standard doesn't say. 1182 ICS = Self.TryCopyInitialization(From, TTy); 1183 } 1184 } else { 1185 // -- Otherwise: E1 can be converted to match E2 if E1 can be 1186 // implicitly converted to the type that expression E2 would have 1187 // if E2 were converted to an rvalue. 1188 // First find the decayed type. 1189 if (TTy->isFunctionType()) 1190 TTy = Self.Context.getPointerType(TTy); 1191 else if(TTy->isArrayType()) 1192 TTy = Self.Context.getArrayDecayedType(TTy); 1193 1194 // Now try the implicit conversion. 1195 // FIXME: This doesn't detect ambiguities. 1196 ICS = Self.TryImplicitConversion(From, TTy); 1197 } 1198 return false; 1199} 1200 1201/// \brief Try to find a common type for two according to C++0x 5.16p5. 1202/// 1203/// This is part of the parameter validation for the ? operator. If either 1204/// value operand is a class type, overload resolution is used to find a 1205/// conversion to a common type. 1206static bool FindConditionalOverload(Sema &Self, Expr *&LHS, Expr *&RHS, 1207 SourceLocation Loc) { 1208 Expr *Args[2] = { LHS, RHS }; 1209 OverloadCandidateSet CandidateSet; 1210 Self.AddBuiltinOperatorCandidates(OO_Conditional, Args, 2, CandidateSet); 1211 1212 OverloadCandidateSet::iterator Best; 1213 switch (Self.BestViableFunction(CandidateSet, Loc, Best)) { 1214 case Sema::OR_Success: 1215 // We found a match. Perform the conversions on the arguments and move on. 1216 if (Self.PerformImplicitConversion(LHS, Best->BuiltinTypes.ParamTypes[0], 1217 Best->Conversions[0], "converting") || 1218 Self.PerformImplicitConversion(RHS, Best->BuiltinTypes.ParamTypes[1], 1219 Best->Conversions[1], "converting")) 1220 break; 1221 return false; 1222 1223 case Sema::OR_No_Viable_Function: 1224 Self.Diag(Loc, diag::err_typecheck_cond_incompatible_operands) 1225 << LHS->getType() << RHS->getType() 1226 << LHS->getSourceRange() << RHS->getSourceRange(); 1227 return true; 1228 1229 case Sema::OR_Ambiguous: 1230 Self.Diag(Loc, diag::err_conditional_ambiguous_ovl) 1231 << LHS->getType() << RHS->getType() 1232 << LHS->getSourceRange() << RHS->getSourceRange(); 1233 // FIXME: Print the possible common types by printing the return types of 1234 // the viable candidates. 1235 break; 1236 1237 case Sema::OR_Deleted: 1238 assert(false && "Conditional operator has only built-in overloads"); 1239 break; 1240 } 1241 return true; 1242} 1243 1244/// \brief Perform an "extended" implicit conversion as returned by 1245/// TryClassUnification. 1246/// 1247/// TryClassUnification generates ICSs that include reference bindings. 1248/// PerformImplicitConversion is not suitable for this; it chokes if the 1249/// second part of a standard conversion is ICK_DerivedToBase. This function 1250/// handles the reference binding specially. 1251static bool ConvertForConditional(Sema &Self, Expr *&E, 1252 const ImplicitConversionSequence &ICS) 1253{ 1254 if (ICS.ConversionKind == ImplicitConversionSequence::StandardConversion && 1255 ICS.Standard.ReferenceBinding) { 1256 assert(ICS.Standard.DirectBinding && 1257 "TryClassUnification should never generate indirect ref bindings"); 1258 // FIXME: CheckReferenceInit should be able to reuse the ICS instead of 1259 // redoing all the work. 1260 return Self.CheckReferenceInit(E, Self.Context.getLValueReferenceType( 1261 TargetType(ICS))); 1262 } 1263 if (ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion && 1264 ICS.UserDefined.After.ReferenceBinding) { 1265 assert(ICS.UserDefined.After.DirectBinding && 1266 "TryClassUnification should never generate indirect ref bindings"); 1267 return Self.CheckReferenceInit(E, Self.Context.getLValueReferenceType( 1268 TargetType(ICS))); 1269 } 1270 if (Self.PerformImplicitConversion(E, TargetType(ICS), ICS, "converting")) 1271 return true; 1272 return false; 1273} 1274 1275/// \brief Check the operands of ?: under C++ semantics. 1276/// 1277/// See C++ [expr.cond]. Note that LHS is never null, even for the GNU x ?: y 1278/// extension. In this case, LHS == Cond. (But they're not aliases.) 1279QualType Sema::CXXCheckConditionalOperands(Expr *&Cond, Expr *&LHS, Expr *&RHS, 1280 SourceLocation QuestionLoc) { 1281 // FIXME: Handle C99's complex types, vector types, block pointers and Obj-C++ 1282 // interface pointers. 1283 1284 // C++0x 5.16p1 1285 // The first expression is contextually converted to bool. 1286 if (!Cond->isTypeDependent()) { 1287 if (CheckCXXBooleanCondition(Cond)) 1288 return QualType(); 1289 } 1290 1291 // Either of the arguments dependent? 1292 if (LHS->isTypeDependent() || RHS->isTypeDependent()) 1293 return Context.DependentTy; 1294 1295 // C++0x 5.16p2 1296 // If either the second or the third operand has type (cv) void, ... 1297 QualType LTy = LHS->getType(); 1298 QualType RTy = RHS->getType(); 1299 bool LVoid = LTy->isVoidType(); 1300 bool RVoid = RTy->isVoidType(); 1301 if (LVoid || RVoid) { 1302 // ... then the [l2r] conversions are performed on the second and third 1303 // operands ... 1304 DefaultFunctionArrayConversion(LHS); 1305 DefaultFunctionArrayConversion(RHS); 1306 LTy = LHS->getType(); 1307 RTy = RHS->getType(); 1308 1309 // ... and one of the following shall hold: 1310 // -- The second or the third operand (but not both) is a throw- 1311 // expression; the result is of the type of the other and is an rvalue. 1312 bool LThrow = isa<CXXThrowExpr>(LHS); 1313 bool RThrow = isa<CXXThrowExpr>(RHS); 1314 if (LThrow && !RThrow) 1315 return RTy; 1316 if (RThrow && !LThrow) 1317 return LTy; 1318 1319 // -- Both the second and third operands have type void; the result is of 1320 // type void and is an rvalue. 1321 if (LVoid && RVoid) 1322 return Context.VoidTy; 1323 1324 // Neither holds, error. 1325 Diag(QuestionLoc, diag::err_conditional_void_nonvoid) 1326 << (LVoid ? RTy : LTy) << (LVoid ? 0 : 1) 1327 << LHS->getSourceRange() << RHS->getSourceRange(); 1328 return QualType(); 1329 } 1330 1331 // Neither is void. 1332 1333 // C++0x 5.16p3 1334 // Otherwise, if the second and third operand have different types, and 1335 // either has (cv) class type, and attempt is made to convert each of those 1336 // operands to the other. 1337 if (Context.getCanonicalType(LTy) != Context.getCanonicalType(RTy) && 1338 (LTy->isRecordType() || RTy->isRecordType())) { 1339 ImplicitConversionSequence ICSLeftToRight, ICSRightToLeft; 1340 // These return true if a single direction is already ambiguous. 1341 if (TryClassUnification(*this, LHS, RHS, QuestionLoc, ICSLeftToRight)) 1342 return QualType(); 1343 if (TryClassUnification(*this, RHS, LHS, QuestionLoc, ICSRightToLeft)) 1344 return QualType(); 1345 1346 bool HaveL2R = ICSLeftToRight.ConversionKind != 1347 ImplicitConversionSequence::BadConversion; 1348 bool HaveR2L = ICSRightToLeft.ConversionKind != 1349 ImplicitConversionSequence::BadConversion; 1350 // If both can be converted, [...] the program is ill-formed. 1351 if (HaveL2R && HaveR2L) { 1352 Diag(QuestionLoc, diag::err_conditional_ambiguous) 1353 << LTy << RTy << LHS->getSourceRange() << RHS->getSourceRange(); 1354 return QualType(); 1355 } 1356 1357 // If exactly one conversion is possible, that conversion is applied to 1358 // the chosen operand and the converted operands are used in place of the 1359 // original operands for the remainder of this section. 1360 if (HaveL2R) { 1361 if (ConvertForConditional(*this, LHS, ICSLeftToRight)) 1362 return QualType(); 1363 LTy = LHS->getType(); 1364 } else if (HaveR2L) { 1365 if (ConvertForConditional(*this, RHS, ICSRightToLeft)) 1366 return QualType(); 1367 RTy = RHS->getType(); 1368 } 1369 } 1370 1371 // C++0x 5.16p4 1372 // If the second and third operands are lvalues and have the same type, 1373 // the result is of that type [...] 1374 bool Same = Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy); 1375 if (Same && LHS->isLvalue(Context) == Expr::LV_Valid && 1376 RHS->isLvalue(Context) == Expr::LV_Valid) 1377 return LTy; 1378 1379 // C++0x 5.16p5 1380 // Otherwise, the result is an rvalue. If the second and third operands 1381 // do not have the same type, and either has (cv) class type, ... 1382 if (!Same && (LTy->isRecordType() || RTy->isRecordType())) { 1383 // ... overload resolution is used to determine the conversions (if any) 1384 // to be applied to the operands. If the overload resolution fails, the 1385 // program is ill-formed. 1386 if (FindConditionalOverload(*this, LHS, RHS, QuestionLoc)) 1387 return QualType(); 1388 } 1389 1390 // C++0x 5.16p6 1391 // LValue-to-rvalue, array-to-pointer, and function-to-pointer standard 1392 // conversions are performed on the second and third operands. 1393 DefaultFunctionArrayConversion(LHS); 1394 DefaultFunctionArrayConversion(RHS); 1395 LTy = LHS->getType(); 1396 RTy = RHS->getType(); 1397 1398 // After those conversions, one of the following shall hold: 1399 // -- The second and third operands have the same type; the result 1400 // is of that type. 1401 if (Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy)) 1402 return LTy; 1403 1404 // -- The second and third operands have arithmetic or enumeration type; 1405 // the usual arithmetic conversions are performed to bring them to a 1406 // common type, and the result is of that type. 1407 if (LTy->isArithmeticType() && RTy->isArithmeticType()) { 1408 UsualArithmeticConversions(LHS, RHS); 1409 return LHS->getType(); 1410 } 1411 1412 // -- The second and third operands have pointer type, or one has pointer 1413 // type and the other is a null pointer constant; pointer conversions 1414 // and qualification conversions are performed to bring them to their 1415 // composite pointer type. The result is of the composite pointer type. 1416 QualType Composite = FindCompositePointerType(LHS, RHS); 1417 if (!Composite.isNull()) 1418 return Composite; 1419 1420 // Fourth bullet is same for pointers-to-member. However, the possible 1421 // conversions are far more limited: we have null-to-pointer, upcast of 1422 // containing class, and second-level cv-ness. 1423 // cv-ness is not a union, but must match one of the two operands. (Which, 1424 // frankly, is stupid.) 1425 const MemberPointerType *LMemPtr = LTy->getAs<MemberPointerType>(); 1426 const MemberPointerType *RMemPtr = RTy->getAs<MemberPointerType>(); 1427 if (LMemPtr && RHS->isNullPointerConstant(Context)) { 1428 ImpCastExprToType(RHS, LTy); 1429 return LTy; 1430 } 1431 if (RMemPtr && LHS->isNullPointerConstant(Context)) { 1432 ImpCastExprToType(LHS, RTy); 1433 return RTy; 1434 } 1435 if (LMemPtr && RMemPtr) { 1436 QualType LPointee = LMemPtr->getPointeeType(); 1437 QualType RPointee = RMemPtr->getPointeeType(); 1438 // First, we check that the unqualified pointee type is the same. If it's 1439 // not, there's no conversion that will unify the two pointers. 1440 if (Context.getCanonicalType(LPointee).getUnqualifiedType() == 1441 Context.getCanonicalType(RPointee).getUnqualifiedType()) { 1442 // Second, we take the greater of the two cv qualifications. If neither 1443 // is greater than the other, the conversion is not possible. 1444 unsigned Q = LPointee.getCVRQualifiers() | RPointee.getCVRQualifiers(); 1445 if (Q == LPointee.getCVRQualifiers() || Q == RPointee.getCVRQualifiers()){ 1446 // Third, we check if either of the container classes is derived from 1447 // the other. 1448 QualType LContainer(LMemPtr->getClass(), 0); 1449 QualType RContainer(RMemPtr->getClass(), 0); 1450 QualType MoreDerived; 1451 if (Context.getCanonicalType(LContainer) == 1452 Context.getCanonicalType(RContainer)) 1453 MoreDerived = LContainer; 1454 else if (IsDerivedFrom(LContainer, RContainer)) 1455 MoreDerived = LContainer; 1456 else if (IsDerivedFrom(RContainer, LContainer)) 1457 MoreDerived = RContainer; 1458 1459 if (!MoreDerived.isNull()) { 1460 // The type 'Q Pointee (MoreDerived::*)' is the common type. 1461 // We don't use ImpCastExprToType here because this could still fail 1462 // for ambiguous or inaccessible conversions. 1463 QualType Common = Context.getMemberPointerType( 1464 LPointee.getQualifiedType(Q), MoreDerived.getTypePtr()); 1465 if (PerformImplicitConversion(LHS, Common, "converting")) 1466 return QualType(); 1467 if (PerformImplicitConversion(RHS, Common, "converting")) 1468 return QualType(); 1469 return Common; 1470 } 1471 } 1472 } 1473 } 1474 1475 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 1476 << LHS->getType() << RHS->getType() 1477 << LHS->getSourceRange() << RHS->getSourceRange(); 1478 return QualType(); 1479} 1480 1481/// \brief Find a merged pointer type and convert the two expressions to it. 1482/// 1483/// This finds the composite pointer type for @p E1 and @p E2 according to 1484/// C++0x 5.9p2. It converts both expressions to this type and returns it. 1485/// It does not emit diagnostics. 1486QualType Sema::FindCompositePointerType(Expr *&E1, Expr *&E2) { 1487 assert(getLangOptions().CPlusPlus && "This function assumes C++"); 1488 QualType T1 = E1->getType(), T2 = E2->getType(); 1489 if(!T1->isAnyPointerType() && !T2->isAnyPointerType()) 1490 return QualType(); 1491 1492 // C++0x 5.9p2 1493 // Pointer conversions and qualification conversions are performed on 1494 // pointer operands to bring them to their composite pointer type. If 1495 // one operand is a null pointer constant, the composite pointer type is 1496 // the type of the other operand. 1497 if (E1->isNullPointerConstant(Context)) { 1498 ImpCastExprToType(E1, T2); 1499 return T2; 1500 } 1501 if (E2->isNullPointerConstant(Context)) { 1502 ImpCastExprToType(E2, T1); 1503 return T1; 1504 } 1505 // Now both have to be pointers. 1506 if(!T1->isPointerType() || !T2->isPointerType()) 1507 return QualType(); 1508 1509 // Otherwise, of one of the operands has type "pointer to cv1 void," then 1510 // the other has type "pointer to cv2 T" and the composite pointer type is 1511 // "pointer to cv12 void," where cv12 is the union of cv1 and cv2. 1512 // Otherwise, the composite pointer type is a pointer type similar to the 1513 // type of one of the operands, with a cv-qualification signature that is 1514 // the union of the cv-qualification signatures of the operand types. 1515 // In practice, the first part here is redundant; it's subsumed by the second. 1516 // What we do here is, we build the two possible composite types, and try the 1517 // conversions in both directions. If only one works, or if the two composite 1518 // types are the same, we have succeeded. 1519 llvm::SmallVector<unsigned, 4> QualifierUnion; 1520 QualType Composite1 = T1, Composite2 = T2; 1521 const PointerType *Ptr1, *Ptr2; 1522 while ((Ptr1 = Composite1->getAs<PointerType>()) && 1523 (Ptr2 = Composite2->getAs<PointerType>())) { 1524 Composite1 = Ptr1->getPointeeType(); 1525 Composite2 = Ptr2->getPointeeType(); 1526 QualifierUnion.push_back( 1527 Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers()); 1528 } 1529 // Rewrap the composites as pointers with the union CVRs. 1530 for (llvm::SmallVector<unsigned, 4>::iterator I = QualifierUnion.begin(), 1531 E = QualifierUnion.end(); I != E; ++I) { 1532 Composite1 = Context.getPointerType(Composite1.getQualifiedType(*I)); 1533 Composite2 = Context.getPointerType(Composite2.getQualifiedType(*I)); 1534 } 1535 1536 ImplicitConversionSequence E1ToC1 = TryImplicitConversion(E1, Composite1); 1537 ImplicitConversionSequence E2ToC1 = TryImplicitConversion(E2, Composite1); 1538 ImplicitConversionSequence E1ToC2, E2ToC2; 1539 E1ToC2.ConversionKind = ImplicitConversionSequence::BadConversion; 1540 E2ToC2.ConversionKind = ImplicitConversionSequence::BadConversion; 1541 if (Context.getCanonicalType(Composite1) != 1542 Context.getCanonicalType(Composite2)) { 1543 E1ToC2 = TryImplicitConversion(E1, Composite2); 1544 E2ToC2 = TryImplicitConversion(E2, Composite2); 1545 } 1546 1547 bool ToC1Viable = E1ToC1.ConversionKind != 1548 ImplicitConversionSequence::BadConversion 1549 && E2ToC1.ConversionKind != 1550 ImplicitConversionSequence::BadConversion; 1551 bool ToC2Viable = E1ToC2.ConversionKind != 1552 ImplicitConversionSequence::BadConversion 1553 && E2ToC2.ConversionKind != 1554 ImplicitConversionSequence::BadConversion; 1555 if (ToC1Viable && !ToC2Viable) { 1556 if (!PerformImplicitConversion(E1, Composite1, E1ToC1, "converting") && 1557 !PerformImplicitConversion(E2, Composite1, E2ToC1, "converting")) 1558 return Composite1; 1559 } 1560 if (ToC2Viable && !ToC1Viable) { 1561 if (!PerformImplicitConversion(E1, Composite2, E1ToC2, "converting") && 1562 !PerformImplicitConversion(E2, Composite2, E2ToC2, "converting")) 1563 return Composite2; 1564 } 1565 return QualType(); 1566} 1567 1568Sema::OwningExprResult Sema::MaybeBindToTemporary(Expr *E) { 1569 const RecordType *RT = E->getType()->getAs<RecordType>(); 1570 if (!RT) 1571 return Owned(E); 1572 1573 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 1574 if (RD->hasTrivialDestructor()) 1575 return Owned(E); 1576 1577 CXXTemporary *Temp = CXXTemporary::Create(Context, 1578 RD->getDestructor(Context)); 1579 ExprTemporaries.push_back(Temp); 1580 if (CXXDestructorDecl *Destructor = 1581 const_cast<CXXDestructorDecl*>(RD->getDestructor(Context))) 1582 MarkDeclarationReferenced(E->getExprLoc(), Destructor); 1583 // FIXME: Add the temporary to the temporaries vector. 1584 return Owned(CXXBindTemporaryExpr::Create(Context, Temp, E)); 1585} 1586 1587Expr *Sema::MaybeCreateCXXExprWithTemporaries(Expr *SubExpr, 1588 bool ShouldDestroyTemps) { 1589 assert(SubExpr && "sub expression can't be null!"); 1590 1591 if (ExprTemporaries.empty()) 1592 return SubExpr; 1593 1594 Expr *E = CXXExprWithTemporaries::Create(Context, SubExpr, 1595 &ExprTemporaries[0], 1596 ExprTemporaries.size(), 1597 ShouldDestroyTemps); 1598 ExprTemporaries.clear(); 1599 1600 return E; 1601} 1602 1603Sema::OwningExprResult Sema::ActOnFinishFullExpr(ExprArg Arg) { 1604 Expr *FullExpr = Arg.takeAs<Expr>(); 1605 if (FullExpr) 1606 FullExpr = MaybeCreateCXXExprWithTemporaries(FullExpr, 1607 /*ShouldDestroyTemps=*/true); 1608 1609 return Owned(FullExpr); 1610} 1611