1 //===--- SemaExprCXX.cpp - Semantic Analysis for Expressions --------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements semantic analysis for C++ expressions.
12 //===----------------------------------------------------------------------===//
14 #include "SemaInherit.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"
22 using namespace clang;
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.
29 Sema::OwningExprResult
30 Sema::ActOnCXXConversionFunctionExpr(Scope *S, SourceLocation OperatorLoc,
31 TypeTy *Ty, bool HasTrailingLParen,
32 const CXXScopeSpec &SS,
33 bool isAddressOfOperand) {
34 QualType ConvType = QualType::getFromOpaquePtr(Ty);
35 QualType ConvTypeCanon = Context.getCanonicalType(ConvType);
36 DeclarationName ConvName
37 = Context.DeclarationNames.getCXXConversionFunctionName(ConvTypeCanon);
38 return ActOnDeclarationNameExpr(S, OperatorLoc, ConvName, HasTrailingLParen,
39 &SS, isAddressOfOperand);
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.
47 Sema::OwningExprResult
48 Sema::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,
58 /// ActOnCXXTypeidOfType - Parse typeid( type-id ).
59 Action::OwningExprResult
60 Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc,
61 bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
62 NamespaceDecl *StdNs = GetStdNamespace();
64 return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));
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));
72 QualType TypeInfoType = Context.getTypeDeclType(TypeInfoRecordDecl);
74 return Owned(new (Context) CXXTypeidExpr(isType, TyOrExpr,
75 TypeInfoType.withConst(),
76 SourceRange(OpLoc, RParenLoc)));
79 /// ActOnCXXBoolLiteral - Parse {true,false} literals.
80 Action::OwningExprResult
81 Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) {
82 assert((Kind == tok::kw_true || Kind == tok::kw_false) &&
83 "Unknown C++ Boolean value!");
84 return Owned(new (Context) CXXBoolLiteralExpr(Kind == tok::kw_true,
85 Context.BoolTy, OpLoc));
88 /// ActOnCXXNullPtrLiteral - Parse 'nullptr'.
89 Action::OwningExprResult
90 Sema::ActOnCXXNullPtrLiteral(SourceLocation Loc) {
91 return Owned(new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc));
94 /// ActOnCXXThrow - Parse throw expressions.
95 Action::OwningExprResult
96 Sema::ActOnCXXThrow(SourceLocation OpLoc, ExprArg E) {
97 Expr *Ex = E.takeAs<Expr>();
98 if (Ex && !Ex->isTypeDependent() && CheckCXXThrowOperand(OpLoc, Ex))
100 return Owned(new (Context) CXXThrowExpr(Ex, Context.VoidTy, OpLoc));
103 /// CheckCXXThrowOperand - Validate the operand of a throw.
104 bool Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc, Expr *&E) {
105 // C++ [except.throw]p3:
106 // [...] adjusting the type from "array of T" or "function returning T"
107 // to "pointer to T" or "pointer to function returning T", [...]
108 DefaultFunctionArrayConversion(E);
110 // If the type of the exception would be an incomplete type or a pointer
111 // to an incomplete type other than (cv) void the program is ill-formed.
112 QualType Ty = E->getType();
114 if (const PointerType* Ptr = Ty->getAsPointerType()) {
115 Ty = Ptr->getPointeeType();
118 if (!isPointer || !Ty->isVoidType()) {
119 if (RequireCompleteType(ThrowLoc, Ty,
120 isPointer ? diag::err_throw_incomplete_ptr
121 : diag::err_throw_incomplete,
122 E->getSourceRange(), SourceRange(), QualType()))
126 // FIXME: Construct a temporary here.
130 Action::OwningExprResult Sema::ActOnCXXThis(SourceLocation ThisLoc) {
131 /// C++ 9.3.2: In the body of a non-static member function, the keyword this
132 /// is a non-lvalue expression whose value is the address of the object for
133 /// which the function is called.
135 if (!isa<FunctionDecl>(CurContext))
136 return ExprError(Diag(ThisLoc, diag::err_invalid_this_use));
138 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(CurContext))
139 if (MD->isInstance())
140 return Owned(new (Context) CXXThisExpr(ThisLoc,
141 MD->getThisType(Context)));
143 return ExprError(Diag(ThisLoc, diag::err_invalid_this_use));
146 /// ActOnCXXTypeConstructExpr - Parse construction of a specified type.
147 /// Can be interpreted either as function-style casting ("int(x)")
148 /// or class type construction ("ClassType(x,y,z)")
149 /// or creation of a value-initialized type ("int()").
150 Action::OwningExprResult
151 Sema::ActOnCXXTypeConstructExpr(SourceRange TypeRange, TypeTy *TypeRep,
152 SourceLocation LParenLoc,
154 SourceLocation *CommaLocs,
155 SourceLocation RParenLoc) {
156 assert(TypeRep && "Missing type!");
157 QualType Ty = QualType::getFromOpaquePtr(TypeRep);
158 unsigned NumExprs = exprs.size();
159 Expr **Exprs = (Expr**)exprs.get();
160 SourceLocation TyBeginLoc = TypeRange.getBegin();
161 SourceRange FullRange = SourceRange(TyBeginLoc, RParenLoc);
163 if (Ty->isDependentType() ||
164 CallExpr::hasAnyTypeDependentArguments(Exprs, NumExprs)) {
167 return Owned(CXXUnresolvedConstructExpr::Create(Context,
168 TypeRange.getBegin(), Ty,
175 // C++ [expr.type.conv]p1:
176 // If the expression list is a single expression, the type conversion
177 // expression is equivalent (in definedness, and if defined in meaning) to the
178 // corresponding cast expression.
181 if (CheckCastTypes(TypeRange, Ty, Exprs[0]))
184 return Owned(new (Context) CXXFunctionalCastExpr(Ty.getNonReferenceType(),
185 Ty, TyBeginLoc, Exprs[0],
189 if (const RecordType *RT = Ty->getAsRecordType()) {
190 CXXRecordDecl *Record = cast<CXXRecordDecl>(RT->getDecl());
192 // FIXME: We should always create a CXXTemporaryObjectExpr here unless
193 // both the ctor and dtor are trivial.
194 if (NumExprs > 1 || Record->hasUserDeclaredConstructor()) {
195 CXXConstructorDecl *Constructor
196 = PerformInitializationByConstructor(Ty, Exprs, NumExprs,
197 TypeRange.getBegin(),
198 SourceRange(TypeRange.getBegin(),
207 Expr *E = new (Context) CXXTemporaryObjectExpr(Context, Constructor,
208 Ty, TyBeginLoc, Exprs,
209 NumExprs, RParenLoc);
210 return MaybeBindToTemporary(E);
213 // Fall through to value-initialize an object of class type that
214 // doesn't have a user-declared default constructor.
217 // C++ [expr.type.conv]p1:
218 // If the expression list specifies more than a single value, the type shall
219 // be a class with a suitably declared constructor.
222 return ExprError(Diag(CommaLocs[0],
223 diag::err_builtin_func_cast_more_than_one_arg)
226 assert(NumExprs == 0 && "Expected 0 expressions");
228 // C++ [expr.type.conv]p2:
229 // The expression T(), where T is a simple-type-specifier for a non-array
230 // complete object type or the (possibly cv-qualified) void type, creates an
231 // rvalue of the specified type, which is value-initialized.
233 if (Ty->isArrayType())
234 return ExprError(Diag(TyBeginLoc,
235 diag::err_value_init_for_array_type) << FullRange);
236 if (!Ty->isDependentType() && !Ty->isVoidType() &&
237 RequireCompleteType(TyBeginLoc, Ty,
238 diag::err_invalid_incomplete_type_use, FullRange))
241 if (RequireNonAbstractType(TyBeginLoc, Ty,
242 diag::err_allocation_of_abstract_type))
246 return Owned(new (Context) CXXZeroInitValueExpr(Ty, TyBeginLoc, RParenLoc));
250 /// ActOnCXXNew - Parsed a C++ 'new' expression (C++ 5.3.4), as in e.g.:
251 /// @code new (memory) int[size][4] @endcode
253 /// @code ::new Foo(23, "hello") @endcode
254 /// For the interpretation of this heap of arguments, consult the base version.
255 Action::OwningExprResult
256 Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal,
257 SourceLocation PlacementLParen, MultiExprArg PlacementArgs,
258 SourceLocation PlacementRParen, bool ParenTypeId,
259 Declarator &D, SourceLocation ConstructorLParen,
260 MultiExprArg ConstructorArgs,
261 SourceLocation ConstructorRParen)
265 // If the specified type is an array, unwrap it and save the expression.
266 if (D.getNumTypeObjects() > 0 &&
267 D.getTypeObject(0).Kind == DeclaratorChunk::Array) {
268 DeclaratorChunk &Chunk = D.getTypeObject(0);
269 if (Chunk.Arr.hasStatic)
270 return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new)
271 << D.getSourceRange());
272 if (!Chunk.Arr.NumElts)
273 return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size)
274 << D.getSourceRange());
275 ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts);
279 QualType AllocType = GetTypeForDeclarator(D, /*Scope=*/0, Skip);
280 if (D.isInvalidType())
283 // Every dimension shall be of constant size.
285 QualType ElementType = AllocType;
286 while (const ArrayType *Array = Context.getAsArrayType(ElementType)) {
287 if (!Array->isConstantArrayType()) {
288 Diag(D.getTypeObject(i).Loc, diag::err_new_array_nonconst)
289 << static_cast<Expr*>(D.getTypeObject(i).Arr.NumElts)->getSourceRange();
292 ElementType = Array->getElementType();
296 return BuildCXXNew(StartLoc, UseGlobal,
302 D.getSourceRange().getBegin(),
306 move(ConstructorArgs),
310 Sema::OwningExprResult
311 Sema::BuildCXXNew(SourceLocation StartLoc, bool UseGlobal,
312 SourceLocation PlacementLParen,
313 MultiExprArg PlacementArgs,
314 SourceLocation PlacementRParen,
317 SourceLocation TypeLoc,
318 SourceRange TypeRange,
320 SourceLocation ConstructorLParen,
321 MultiExprArg ConstructorArgs,
322 SourceLocation ConstructorRParen) {
323 if (CheckAllocatedType(AllocType, TypeLoc, TypeRange))
326 QualType ResultType = Context.getPointerType(AllocType);
328 // That every array dimension except the first is constant was already
329 // checked by the type check above.
331 // C++ 5.3.4p6: "The expression in a direct-new-declarator shall have integral
332 // or enumeration type with a non-negative value."
333 Expr *ArraySize = (Expr *)ArraySizeE.get();
334 if (ArraySize && !ArraySize->isTypeDependent()) {
335 QualType SizeType = ArraySize->getType();
336 if (!SizeType->isIntegralType() && !SizeType->isEnumeralType())
337 return ExprError(Diag(ArraySize->getSourceRange().getBegin(),
338 diag::err_array_size_not_integral)
339 << SizeType << ArraySize->getSourceRange());
340 // Let's see if this is a constant < 0. If so, we reject it out of hand.
341 // We don't care about special rules, so we tell the machinery it's not
342 // evaluated - it gives us a result in more cases.
343 if (!ArraySize->isValueDependent()) {
345 if (ArraySize->isIntegerConstantExpr(Value, Context, 0, false)) {
346 if (Value < llvm::APSInt(
347 llvm::APInt::getNullValue(Value.getBitWidth()), false))
348 return ExprError(Diag(ArraySize->getSourceRange().getBegin(),
349 diag::err_typecheck_negative_array_size)
350 << ArraySize->getSourceRange());
355 FunctionDecl *OperatorNew = 0;
356 FunctionDecl *OperatorDelete = 0;
357 Expr **PlaceArgs = (Expr**)PlacementArgs.get();
358 unsigned NumPlaceArgs = PlacementArgs.size();
359 if (!AllocType->isDependentType() &&
360 !Expr::hasAnyTypeDependentArguments(PlaceArgs, NumPlaceArgs) &&
361 FindAllocationFunctions(StartLoc,
362 SourceRange(PlacementLParen, PlacementRParen),
363 UseGlobal, AllocType, ArraySize, PlaceArgs,
364 NumPlaceArgs, OperatorNew, OperatorDelete))
367 bool Init = ConstructorLParen.isValid();
368 // --- Choosing a constructor ---
370 // 1) If T is a POD and there's no initializer (ConstructorLParen is invalid)
371 // the object is not initialized. If the object, or any part of it, is
372 // const-qualified, it's an error.
373 // 2) If T is a POD and there's an empty initializer, the object is value-
375 // 3) If T is a POD and there's one initializer argument, the object is copy-
377 // 4) If T is a POD and there's more initializer arguments, it's an error.
378 // 5) If T is not a POD, the initializer arguments are used as constructor
381 // Or by the C++0x formulation:
382 // 1) If there's no initializer, the object is default-initialized according
384 // 2) Otherwise, the object is direct-initialized.
385 CXXConstructorDecl *Constructor = 0;
386 Expr **ConsArgs = (Expr**)ConstructorArgs.get();
387 const RecordType *RT;
388 unsigned NumConsArgs = ConstructorArgs.size();
389 if (AllocType->isDependentType()) {
390 // Skip all the checks.
392 else if ((RT = AllocType->getAsRecordType()) &&
393 !AllocType->isAggregateType()) {
394 Constructor = PerformInitializationByConstructor(
395 AllocType, ConsArgs, NumConsArgs,
397 SourceRange(TypeLoc, ConstructorRParen),
398 RT->getDecl()->getDeclName(),
399 NumConsArgs != 0 ? IK_Direct : IK_Default);
404 // FIXME: Check that no subpart is const.
405 if (AllocType.isConstQualified())
406 return ExprError(Diag(StartLoc, diag::err_new_uninitialized_const)
408 } else if (NumConsArgs == 0) {
409 // Object is value-initialized. Do nothing.
410 } else if (NumConsArgs == 1) {
411 // Object is direct-initialized.
412 // FIXME: What DeclarationName do we pass in here?
413 if (CheckInitializerTypes(ConsArgs[0], AllocType, StartLoc,
414 DeclarationName() /*AllocType.getAsString()*/,
415 /*DirectInit=*/true))
418 return ExprError(Diag(StartLoc,
419 diag::err_builtin_direct_init_more_than_one_arg)
420 << SourceRange(ConstructorLParen, ConstructorRParen));
424 // FIXME: Also check that the destructor is accessible. (C++ 5.3.4p16)
426 PlacementArgs.release();
427 ConstructorArgs.release();
428 ArraySizeE.release();
429 return Owned(new (Context) CXXNewExpr(UseGlobal, OperatorNew, PlaceArgs,
430 NumPlaceArgs, ParenTypeId, ArraySize, Constructor, Init,
431 ConsArgs, NumConsArgs, OperatorDelete, ResultType,
432 StartLoc, Init ? ConstructorRParen : SourceLocation()));
435 /// CheckAllocatedType - Checks that a type is suitable as the allocated type
436 /// in a new-expression.
437 /// dimension off and stores the size expression in ArraySize.
438 bool Sema::CheckAllocatedType(QualType AllocType, SourceLocation Loc,
441 // C++ 5.3.4p1: "[The] type shall be a complete object type, but not an
442 // abstract class type or array thereof.
443 if (AllocType->isFunctionType())
444 return Diag(Loc, diag::err_bad_new_type)
445 << AllocType << 0 << R;
446 else if (AllocType->isReferenceType())
447 return Diag(Loc, diag::err_bad_new_type)
448 << AllocType << 1 << R;
449 else if (!AllocType->isDependentType() &&
450 RequireCompleteType(Loc, AllocType,
451 diag::err_new_incomplete_type,
454 else if (RequireNonAbstractType(Loc, AllocType,
455 diag::err_allocation_of_abstract_type))
461 /// FindAllocationFunctions - Finds the overloads of operator new and delete
462 /// that are appropriate for the allocation.
463 bool Sema::FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range,
464 bool UseGlobal, QualType AllocType,
465 bool IsArray, Expr **PlaceArgs,
466 unsigned NumPlaceArgs,
467 FunctionDecl *&OperatorNew,
468 FunctionDecl *&OperatorDelete)
470 // --- Choosing an allocation function ---
471 // C++ 5.3.4p8 - 14 & 18
472 // 1) If UseGlobal is true, only look in the global scope. Else, also look
473 // in the scope of the allocated class.
474 // 2) If an array size is given, look for operator new[], else look for
476 // 3) The first argument is always size_t. Append the arguments from the
478 // FIXME: Also find the appropriate delete operator.
480 llvm::SmallVector<Expr*, 8> AllocArgs(1 + NumPlaceArgs);
481 // We don't care about the actual value of this argument.
482 // FIXME: Should the Sema create the expression and embed it in the syntax
483 // tree? Or should the consumer just recalculate the value?
484 AllocArgs[0] = new (Context) IntegerLiteral(llvm::APInt::getNullValue(
485 Context.Target.getPointerWidth(0)),
486 Context.getSizeType(),
488 std::copy(PlaceArgs, PlaceArgs + NumPlaceArgs, AllocArgs.begin() + 1);
490 DeclarationName NewName = Context.DeclarationNames.getCXXOperatorName(
491 IsArray ? OO_Array_New : OO_New);
492 if (AllocType->isRecordType() && !UseGlobal) {
493 CXXRecordDecl *Record
494 = cast<CXXRecordDecl>(AllocType->getAsRecordType()->getDecl());
495 // FIXME: We fail to find inherited overloads.
496 if (FindAllocationOverload(StartLoc, Range, NewName, &AllocArgs[0],
497 AllocArgs.size(), Record, /*AllowMissing=*/true,
502 // Didn't find a member overload. Look for a global one.
503 DeclareGlobalNewDelete();
504 DeclContext *TUDecl = Context.getTranslationUnitDecl();
505 if (FindAllocationOverload(StartLoc, Range, NewName, &AllocArgs[0],
506 AllocArgs.size(), TUDecl, /*AllowMissing=*/false,
511 // FindAllocationOverload can change the passed in arguments, so we need to
513 if (NumPlaceArgs > 0)
514 std::copy(&AllocArgs[1], AllocArgs.end(), PlaceArgs);
516 // FIXME: This is leaked on error. But so much is currently in Sema that it's
517 // easier to clean it in one go.
518 AllocArgs[0]->Destroy(Context);
522 /// FindAllocationOverload - Find an fitting overload for the allocation
523 /// function in the specified scope.
524 bool Sema::FindAllocationOverload(SourceLocation StartLoc, SourceRange Range,
525 DeclarationName Name, Expr** Args,
526 unsigned NumArgs, DeclContext *Ctx,
527 bool AllowMissing, FunctionDecl *&Operator)
529 DeclContext::lookup_iterator Alloc, AllocEnd;
530 llvm::tie(Alloc, AllocEnd) = Ctx->lookup(Context, Name);
531 if (Alloc == AllocEnd) {
534 return Diag(StartLoc, diag::err_ovl_no_viable_function_in_call)
538 OverloadCandidateSet Candidates;
539 for (; Alloc != AllocEnd; ++Alloc) {
540 // Even member operator new/delete are implicitly treated as
541 // static, so don't use AddMemberCandidate.
542 if (FunctionDecl *Fn = dyn_cast<FunctionDecl>(*Alloc))
543 AddOverloadCandidate(Fn, Args, NumArgs, Candidates,
544 /*SuppressUserConversions=*/false);
547 // Do the resolution.
548 OverloadCandidateSet::iterator Best;
549 switch(BestViableFunction(Candidates, Best)) {
552 FunctionDecl *FnDecl = Best->Function;
553 // The first argument is size_t, and the first parameter must be size_t,
554 // too. This is checked on declaration and can be assumed. (It can't be
555 // asserted on, though, since invalid decls are left in there.)
556 for (unsigned i = 1; i < NumArgs; ++i) {
557 // FIXME: Passing word to diagnostic.
558 if (PerformCopyInitialization(Args[i],
559 FnDecl->getParamDecl(i)->getType(),
567 case OR_No_Viable_Function:
568 Diag(StartLoc, diag::err_ovl_no_viable_function_in_call)
570 PrintOverloadCandidates(Candidates, /*OnlyViable=*/false);
574 Diag(StartLoc, diag::err_ovl_ambiguous_call)
576 PrintOverloadCandidates(Candidates, /*OnlyViable=*/true);
580 Diag(StartLoc, diag::err_ovl_deleted_call)
581 << Best->Function->isDeleted()
583 PrintOverloadCandidates(Candidates, /*OnlyViable=*/true);
586 assert(false && "Unreachable, bad result from BestViableFunction");
591 /// DeclareGlobalNewDelete - Declare the global forms of operator new and
592 /// delete. These are:
594 /// void* operator new(std::size_t) throw(std::bad_alloc);
595 /// void* operator new[](std::size_t) throw(std::bad_alloc);
596 /// void operator delete(void *) throw();
597 /// void operator delete[](void *) throw();
599 /// Note that the placement and nothrow forms of new are *not* implicitly
600 /// declared. Their use requires including \<new\>.
601 void Sema::DeclareGlobalNewDelete()
603 if (GlobalNewDeleteDeclared)
605 GlobalNewDeleteDeclared = true;
607 QualType VoidPtr = Context.getPointerType(Context.VoidTy);
608 QualType SizeT = Context.getSizeType();
610 // FIXME: Exception specifications are not added.
611 DeclareGlobalAllocationFunction(
612 Context.DeclarationNames.getCXXOperatorName(OO_New),
614 DeclareGlobalAllocationFunction(
615 Context.DeclarationNames.getCXXOperatorName(OO_Array_New),
617 DeclareGlobalAllocationFunction(
618 Context.DeclarationNames.getCXXOperatorName(OO_Delete),
619 Context.VoidTy, VoidPtr);
620 DeclareGlobalAllocationFunction(
621 Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete),
622 Context.VoidTy, VoidPtr);
625 /// DeclareGlobalAllocationFunction - Declares a single implicit global
626 /// allocation function if it doesn't already exist.
627 void Sema::DeclareGlobalAllocationFunction(DeclarationName Name,
628 QualType Return, QualType Argument)
630 DeclContext *GlobalCtx = Context.getTranslationUnitDecl();
632 // Check if this function is already declared.
634 DeclContext::lookup_iterator Alloc, AllocEnd;
635 for (llvm::tie(Alloc, AllocEnd) = GlobalCtx->lookup(Context, Name);
636 Alloc != AllocEnd; ++Alloc) {
637 // FIXME: Do we need to check for default arguments here?
638 FunctionDecl *Func = cast<FunctionDecl>(*Alloc);
639 if (Func->getNumParams() == 1 &&
640 Context.getCanonicalType(Func->getParamDecl(0)->getType())==Argument)
645 QualType FnType = Context.getFunctionType(Return, &Argument, 1, false, 0);
646 FunctionDecl *Alloc =
647 FunctionDecl::Create(Context, GlobalCtx, SourceLocation(), Name,
648 FnType, FunctionDecl::None, false, true,
650 Alloc->setImplicit();
651 ParmVarDecl *Param = ParmVarDecl::Create(Context, Alloc, SourceLocation(),
652 0, Argument, VarDecl::None, 0);
653 Alloc->setParams(Context, &Param, 1);
655 // FIXME: Also add this declaration to the IdentifierResolver, but
656 // make sure it is at the end of the chain to coincide with the
658 ((DeclContext *)TUScope->getEntity())->addDecl(Context, Alloc);
661 /// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in:
662 /// @code ::delete ptr; @endcode
664 /// @code delete [] ptr; @endcode
665 Action::OwningExprResult
666 Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal,
667 bool ArrayForm, ExprArg Operand)
669 // C++ 5.3.5p1: "The operand shall have a pointer type, or a class type
670 // having a single conversion function to a pointer type. The result has
672 // DR599 amends "pointer type" to "pointer to object type" in both cases.
674 Expr *Ex = (Expr *)Operand.get();
675 if (!Ex->isTypeDependent()) {
676 QualType Type = Ex->getType();
678 if (Type->isRecordType()) {
679 // FIXME: Find that one conversion function and amend the type.
682 if (!Type->isPointerType())
683 return ExprError(Diag(StartLoc, diag::err_delete_operand)
684 << Type << Ex->getSourceRange());
686 QualType Pointee = Type->getAsPointerType()->getPointeeType();
687 if (Pointee->isFunctionType() || Pointee->isVoidType())
688 return ExprError(Diag(StartLoc, diag::err_delete_operand)
689 << Type << Ex->getSourceRange());
690 else if (!Pointee->isDependentType() &&
691 RequireCompleteType(StartLoc, Pointee,
692 diag::warn_delete_incomplete,
693 Ex->getSourceRange()))
696 // FIXME: Look up the correct operator delete overload and pass a pointer
698 // FIXME: Check access and ambiguity of operator delete and destructor.
702 return Owned(new (Context) CXXDeleteExpr(Context.VoidTy, UseGlobal, ArrayForm,
707 /// ActOnCXXConditionDeclarationExpr - Parsed a condition declaration of a
708 /// C++ if/switch/while/for statement.
709 /// e.g: "if (int x = f()) {...}"
710 Action::OwningExprResult
711 Sema::ActOnCXXConditionDeclarationExpr(Scope *S, SourceLocation StartLoc,
713 SourceLocation EqualLoc,
714 ExprArg AssignExprVal) {
715 assert(AssignExprVal.get() && "Null assignment expression");
718 // The declarator shall not specify a function or an array.
719 // The type-specifier-seq shall not contain typedef and shall not declare a
720 // new class or enumeration.
722 assert(D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&
723 "Parser allowed 'typedef' as storage class of condition decl.");
725 QualType Ty = GetTypeForDeclarator(D, S);
727 if (Ty->isFunctionType()) { // The declarator shall not specify a function...
728 // We exit without creating a CXXConditionDeclExpr because a FunctionDecl
729 // would be created and CXXConditionDeclExpr wants a VarDecl.
730 return ExprError(Diag(StartLoc, diag::err_invalid_use_of_function_type)
731 << SourceRange(StartLoc, EqualLoc));
732 } else if (Ty->isArrayType()) { // ...or an array.
733 Diag(StartLoc, diag::err_invalid_use_of_array_type)
734 << SourceRange(StartLoc, EqualLoc);
735 } else if (const RecordType *RT = Ty->getAsRecordType()) {
736 RecordDecl *RD = RT->getDecl();
737 // The type-specifier-seq shall not declare a new class...
738 if (RD->isDefinition() &&
739 (RD->getIdentifier() == 0 || S->isDeclScope(DeclPtrTy::make(RD))))
740 Diag(RD->getLocation(), diag::err_type_defined_in_condition);
741 } else if (const EnumType *ET = Ty->getAsEnumType()) {
742 EnumDecl *ED = ET->getDecl();
743 // ...or enumeration.
744 if (ED->isDefinition() &&
745 (ED->getIdentifier() == 0 || S->isDeclScope(DeclPtrTy::make(ED))))
746 Diag(ED->getLocation(), diag::err_type_defined_in_condition);
749 DeclPtrTy Dcl = ActOnDeclarator(S, D, DeclPtrTy());
752 AddInitializerToDecl(Dcl, move(AssignExprVal), /*DirectInit=*/false);
754 // Mark this variable as one that is declared within a conditional.
755 // We know that the decl had to be a VarDecl because that is the only type of
756 // decl that can be assigned and the grammar requires an '='.
757 VarDecl *VD = cast<VarDecl>(Dcl.getAs<Decl>());
758 VD->setDeclaredInCondition(true);
759 return Owned(new (Context) CXXConditionDeclExpr(StartLoc, EqualLoc, VD));
762 /// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid.
763 bool Sema::CheckCXXBooleanCondition(Expr *&CondExpr) {
765 // The value of a condition that is an initialized declaration in a statement
766 // other than a switch statement is the value of the declared variable
767 // implicitly converted to type bool. If that conversion is ill-formed, the
768 // program is ill-formed.
769 // The value of a condition that is an expression is the value of the
770 // expression, implicitly converted to bool.
772 return PerformContextuallyConvertToBool(CondExpr);
775 /// Helper function to determine whether this is the (deprecated) C++
776 /// conversion from a string literal to a pointer to non-const char or
777 /// non-const wchar_t (for narrow and wide string literals,
780 Sema::IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType) {
781 // Look inside the implicit cast, if it exists.
782 if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From))
783 From = Cast->getSubExpr();
785 // A string literal (2.13.4) that is not a wide string literal can
786 // be converted to an rvalue of type "pointer to char"; a wide
787 // string literal can be converted to an rvalue of type "pointer
788 // to wchar_t" (C++ 4.2p2).
789 if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From))
790 if (const PointerType *ToPtrType = ToType->getAsPointerType())
791 if (const BuiltinType *ToPointeeType
792 = ToPtrType->getPointeeType()->getAsBuiltinType()) {
793 // This conversion is considered only when there is an
794 // explicit appropriate pointer target type (C++ 4.2p2).
795 if (ToPtrType->getPointeeType().getCVRQualifiers() == 0 &&
796 ((StrLit->isWide() && ToPointeeType->isWideCharType()) ||
797 (!StrLit->isWide() &&
798 (ToPointeeType->getKind() == BuiltinType::Char_U ||
799 ToPointeeType->getKind() == BuiltinType::Char_S))))
806 /// PerformImplicitConversion - Perform an implicit conversion of the
807 /// expression From to the type ToType. Returns true if there was an
808 /// error, false otherwise. The expression From is replaced with the
809 /// converted expression. Flavor is the kind of conversion we're
810 /// performing, used in the error message. If @p AllowExplicit,
811 /// explicit user-defined conversions are permitted. @p Elidable should be true
812 /// when called for copies which may be elided (C++ 12.8p15). C++0x overload
813 /// resolution works differently in that case.
815 Sema::PerformImplicitConversion(Expr *&From, QualType ToType,
816 const char *Flavor, bool AllowExplicit,
819 ImplicitConversionSequence ICS;
820 ICS.ConversionKind = ImplicitConversionSequence::BadConversion;
821 if (Elidable && getLangOptions().CPlusPlus0x) {
822 ICS = TryImplicitConversion(From, ToType, /*SuppressUserConversions*/false,
823 AllowExplicit, /*ForceRValue*/true);
825 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) {
826 ICS = TryImplicitConversion(From, ToType, false, AllowExplicit);
828 return PerformImplicitConversion(From, ToType, ICS, Flavor);
831 /// PerformImplicitConversion - Perform an implicit conversion of the
832 /// expression From to the type ToType using the pre-computed implicit
833 /// conversion sequence ICS. Returns true if there was an error, false
834 /// otherwise. The expression From is replaced with the converted
835 /// expression. Flavor is the kind of conversion we're performing,
836 /// used in the error message.
838 Sema::PerformImplicitConversion(Expr *&From, QualType ToType,
839 const ImplicitConversionSequence &ICS,
840 const char* Flavor) {
841 switch (ICS.ConversionKind) {
842 case ImplicitConversionSequence::StandardConversion:
843 if (PerformImplicitConversion(From, ToType, ICS.Standard, Flavor))
847 case ImplicitConversionSequence::UserDefinedConversion:
848 // FIXME: This is, of course, wrong. We'll need to actually call the
849 // constructor or conversion operator, and then cope with the standard
851 ImpCastExprToType(From, ToType.getNonReferenceType(),
852 ToType->isLValueReferenceType());
855 case ImplicitConversionSequence::EllipsisConversion:
856 assert(false && "Cannot perform an ellipsis conversion");
859 case ImplicitConversionSequence::BadConversion:
863 // Everything went well.
867 /// PerformImplicitConversion - Perform an implicit conversion of the
868 /// expression From to the type ToType by following the standard
869 /// conversion sequence SCS. Returns true if there was an error, false
870 /// otherwise. The expression From is replaced with the converted
871 /// expression. Flavor is the context in which we're performing this
872 /// conversion, for use in error messages.
874 Sema::PerformImplicitConversion(Expr *&From, QualType ToType,
875 const StandardConversionSequence& SCS,
876 const char *Flavor) {
877 // Overall FIXME: we are recomputing too many types here and doing far too
878 // much extra work. What this means is that we need to keep track of more
879 // information that is computed when we try the implicit conversion initially,
880 // so that we don't need to recompute anything here.
881 QualType FromType = From->getType();
883 if (SCS.CopyConstructor) {
884 // FIXME: When can ToType be a reference type?
885 assert(!ToType->isReferenceType());
887 // FIXME: Keep track of whether the copy constructor is elidable or not.
888 From = CXXConstructExpr::Create(Context, ToType,
889 SCS.CopyConstructor, false, &From, 1);
893 // Perform the first implicit conversion.
896 case ICK_Lvalue_To_Rvalue:
900 case ICK_Array_To_Pointer:
901 FromType = Context.getArrayDecayedType(FromType);
902 ImpCastExprToType(From, FromType);
905 case ICK_Function_To_Pointer:
906 if (Context.getCanonicalType(FromType) == Context.OverloadTy) {
907 FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(From, ToType, true);
911 if (DiagnoseUseOfDecl(Fn, From->getSourceRange().getBegin()))
914 FixOverloadedFunctionReference(From, Fn);
915 FromType = From->getType();
917 FromType = Context.getPointerType(FromType);
918 ImpCastExprToType(From, FromType);
922 assert(false && "Improper first standard conversion");
926 // Perform the second implicit conversion
927 switch (SCS.Second) {
932 case ICK_Integral_Promotion:
933 case ICK_Floating_Promotion:
934 case ICK_Complex_Promotion:
935 case ICK_Integral_Conversion:
936 case ICK_Floating_Conversion:
937 case ICK_Complex_Conversion:
938 case ICK_Floating_Integral:
939 case ICK_Complex_Real:
940 case ICK_Compatible_Conversion:
941 // FIXME: Go deeper to get the unqualified type!
942 FromType = ToType.getUnqualifiedType();
943 ImpCastExprToType(From, FromType);
946 case ICK_Pointer_Conversion:
947 if (SCS.IncompatibleObjC) {
948 // Diagnose incompatible Objective-C conversions
949 Diag(From->getSourceRange().getBegin(),
950 diag::ext_typecheck_convert_incompatible_pointer)
951 << From->getType() << ToType << Flavor
952 << From->getSourceRange();
955 if (CheckPointerConversion(From, ToType))
957 ImpCastExprToType(From, ToType);
960 case ICK_Pointer_Member:
961 if (CheckMemberPointerConversion(From, ToType))
963 ImpCastExprToType(From, ToType);
966 case ICK_Boolean_Conversion:
967 FromType = Context.BoolTy;
968 ImpCastExprToType(From, FromType);
972 assert(false && "Improper second standard conversion");
981 case ICK_Qualification:
982 // FIXME: Not sure about lvalue vs rvalue here in the presence of rvalue
984 ImpCastExprToType(From, ToType.getNonReferenceType(),
985 ToType->isLValueReferenceType());
989 assert(false && "Improper second standard conversion");
996 Sema::OwningExprResult Sema::ActOnUnaryTypeTrait(UnaryTypeTrait OTT,
997 SourceLocation KWLoc,
998 SourceLocation LParen,
1000 SourceLocation RParen) {
1001 // FIXME: Some of the type traits have requirements. Interestingly, only the
1002 // __is_base_of requirement is explicitly stated to be diagnosed. Indeed, G++
1003 // accepts __is_pod(Incomplete) without complaints, and claims that the type
1006 // There is no point in eagerly computing the value. The traits are designed
1007 // to be used from type trait templates, so Ty will be a template parameter
1009 return Owned(new (Context) UnaryTypeTraitExpr(KWLoc, OTT,
1010 QualType::getFromOpaquePtr(Ty),
1011 RParen, Context.BoolTy));
1014 QualType Sema::CheckPointerToMemberOperands(
1015 Expr *&lex, Expr *&rex, SourceLocation Loc, bool isIndirect)
1017 const char *OpSpelling = isIndirect ? "->*" : ".*";
1019 // The binary operator .* [p3: ->*] binds its second operand, which shall
1020 // be of type "pointer to member of T" (where T is a completely-defined
1021 // class type) [...]
1022 QualType RType = rex->getType();
1023 const MemberPointerType *MemPtr = RType->getAsMemberPointerType();
1025 Diag(Loc, diag::err_bad_memptr_rhs)
1026 << OpSpelling << RType << rex->getSourceRange();
1030 QualType Class(MemPtr->getClass(), 0);
1033 // [...] to its first operand, which shall be of class T or of a class of
1034 // which T is an unambiguous and accessible base class. [p3: a pointer to
1036 QualType LType = lex->getType();
1038 if (const PointerType *Ptr = LType->getAsPointerType())
1039 LType = Ptr->getPointeeType().getNonReferenceType();
1041 Diag(Loc, diag::err_bad_memptr_lhs)
1042 << OpSpelling << 1 << LType << lex->getSourceRange();
1047 if (Context.getCanonicalType(Class).getUnqualifiedType() !=
1048 Context.getCanonicalType(LType).getUnqualifiedType()) {
1049 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false,
1050 /*DetectVirtual=*/false);
1051 // FIXME: Would it be useful to print full ambiguity paths, or is that
1053 if (!IsDerivedFrom(LType, Class, Paths) ||
1054 Paths.isAmbiguous(Context.getCanonicalType(Class))) {
1055 Diag(Loc, diag::err_bad_memptr_lhs) << OpSpelling
1056 << (int)isIndirect << lex->getType() << lex->getSourceRange();
1062 // The result is an object or a function of the type specified by the
1064 // The cv qualifiers are the union of those in the pointer and the left side,
1065 // in accordance with 5.5p5 and 5.2.5.
1066 // FIXME: This returns a dereferenced member function pointer as a normal
1067 // function type. However, the only operation valid on such functions is
1068 // calling them. There's also a GCC extension to get a function pointer to the
1069 // thing, which is another complication, because this type - unlike the type
1070 // that is the result of this expression - takes the class as the first
1072 // We probably need a "MemberFunctionClosureType" or something like that.
1073 QualType Result = MemPtr->getPointeeType();
1074 if (LType.isConstQualified())
1076 if (LType.isVolatileQualified())
1077 Result.addVolatile();
1081 /// \brief Get the target type of a standard or user-defined conversion.
1082 static QualType TargetType(const ImplicitConversionSequence &ICS) {
1083 assert((ICS.ConversionKind ==
1084 ImplicitConversionSequence::StandardConversion ||
1085 ICS.ConversionKind ==
1086 ImplicitConversionSequence::UserDefinedConversion) &&
1087 "function only valid for standard or user-defined conversions");
1088 if (ICS.ConversionKind == ImplicitConversionSequence::StandardConversion)
1089 return QualType::getFromOpaquePtr(ICS.Standard.ToTypePtr);
1090 return QualType::getFromOpaquePtr(ICS.UserDefined.After.ToTypePtr);
1093 /// \brief Try to convert a type to another according to C++0x 5.16p3.
1095 /// This is part of the parameter validation for the ? operator. If either
1096 /// value operand is a class type, the two operands are attempted to be
1097 /// converted to each other. This function does the conversion in one direction.
1098 /// It emits a diagnostic and returns true only if it finds an ambiguous
1100 static bool TryClassUnification(Sema &Self, Expr *From, Expr *To,
1101 SourceLocation QuestionLoc,
1102 ImplicitConversionSequence &ICS)
1105 // The process for determining whether an operand expression E1 of type T1
1106 // can be converted to match an operand expression E2 of type T2 is defined
1108 // -- If E2 is an lvalue:
1109 if (To->isLvalue(Self.Context) == Expr::LV_Valid) {
1110 // E1 can be converted to match E2 if E1 can be implicitly converted to
1111 // type "lvalue reference to T2", subject to the constraint that in the
1112 // conversion the reference must bind directly to E1.
1113 if (!Self.CheckReferenceInit(From,
1114 Self.Context.getLValueReferenceType(To->getType()),
1117 assert((ICS.ConversionKind ==
1118 ImplicitConversionSequence::StandardConversion ||
1119 ICS.ConversionKind ==
1120 ImplicitConversionSequence::UserDefinedConversion) &&
1121 "expected a definite conversion");
1122 bool DirectBinding =
1123 ICS.ConversionKind == ImplicitConversionSequence::StandardConversion ?
1124 ICS.Standard.DirectBinding : ICS.UserDefined.After.DirectBinding;
1129 ICS.ConversionKind = ImplicitConversionSequence::BadConversion;
1130 // -- If E2 is an rvalue, or if the conversion above cannot be done:
1131 // -- if E1 and E2 have class type, and the underlying class types are
1132 // the same or one is a base class of the other:
1133 QualType FTy = From->getType();
1134 QualType TTy = To->getType();
1135 const RecordType *FRec = FTy->getAsRecordType();
1136 const RecordType *TRec = TTy->getAsRecordType();
1137 bool FDerivedFromT = FRec && TRec && Self.IsDerivedFrom(FTy, TTy);
1138 if (FRec && TRec && (FRec == TRec ||
1139 FDerivedFromT || Self.IsDerivedFrom(TTy, FTy))) {
1140 // E1 can be converted to match E2 if the class of T2 is the
1141 // same type as, or a base class of, the class of T1, and
1143 if ((FRec == TRec || FDerivedFromT) && TTy.isAtLeastAsQualifiedAs(FTy)) {
1144 // Could still fail if there's no copy constructor.
1145 // FIXME: Is this a hard error then, or just a conversion failure? The
1146 // standard doesn't say.
1147 ICS = Self.TryCopyInitialization(From, TTy);
1150 // -- Otherwise: E1 can be converted to match E2 if E1 can be
1151 // implicitly converted to the type that expression E2 would have
1152 // if E2 were converted to an rvalue.
1153 // First find the decayed type.
1154 if (TTy->isFunctionType())
1155 TTy = Self.Context.getPointerType(TTy);
1156 else if(TTy->isArrayType())
1157 TTy = Self.Context.getArrayDecayedType(TTy);
1159 // Now try the implicit conversion.
1160 // FIXME: This doesn't detect ambiguities.
1161 ICS = Self.TryImplicitConversion(From, TTy);
1166 /// \brief Try to find a common type for two according to C++0x 5.16p5.
1168 /// This is part of the parameter validation for the ? operator. If either
1169 /// value operand is a class type, overload resolution is used to find a
1170 /// conversion to a common type.
1171 static bool FindConditionalOverload(Sema &Self, Expr *&LHS, Expr *&RHS,
1172 SourceLocation Loc) {
1173 Expr *Args[2] = { LHS, RHS };
1174 OverloadCandidateSet CandidateSet;
1175 Self.AddBuiltinOperatorCandidates(OO_Conditional, Args, 2, CandidateSet);
1177 OverloadCandidateSet::iterator Best;
1178 switch (Self.BestViableFunction(CandidateSet, Best)) {
1179 case Sema::OR_Success:
1180 // We found a match. Perform the conversions on the arguments and move on.
1181 if (Self.PerformImplicitConversion(LHS, Best->BuiltinTypes.ParamTypes[0],
1182 Best->Conversions[0], "converting") ||
1183 Self.PerformImplicitConversion(RHS, Best->BuiltinTypes.ParamTypes[1],
1184 Best->Conversions[1], "converting"))
1188 case Sema::OR_No_Viable_Function:
1189 Self.Diag(Loc, diag::err_typecheck_cond_incompatible_operands)
1190 << LHS->getType() << RHS->getType()
1191 << LHS->getSourceRange() << RHS->getSourceRange();
1194 case Sema::OR_Ambiguous:
1195 Self.Diag(Loc, diag::err_conditional_ambiguous_ovl)
1196 << LHS->getType() << RHS->getType()
1197 << LHS->getSourceRange() << RHS->getSourceRange();
1198 // FIXME: Print the possible common types by printing the return types of
1199 // the viable candidates.
1202 case Sema::OR_Deleted:
1203 assert(false && "Conditional operator has only built-in overloads");
1209 /// \brief Perform an "extended" implicit conversion as returned by
1210 /// TryClassUnification.
1212 /// TryClassUnification generates ICSs that include reference bindings.
1213 /// PerformImplicitConversion is not suitable for this; it chokes if the
1214 /// second part of a standard conversion is ICK_DerivedToBase. This function
1215 /// handles the reference binding specially.
1216 static bool ConvertForConditional(Sema &Self, Expr *&E,
1217 const ImplicitConversionSequence &ICS)
1219 if (ICS.ConversionKind == ImplicitConversionSequence::StandardConversion &&
1220 ICS.Standard.ReferenceBinding) {
1221 assert(ICS.Standard.DirectBinding &&
1222 "TryClassUnification should never generate indirect ref bindings");
1223 // FIXME: CheckReferenceInit should be able to reuse the ICS instead of
1224 // redoing all the work.
1225 return Self.CheckReferenceInit(E, Self.Context.getLValueReferenceType(
1228 if (ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion &&
1229 ICS.UserDefined.After.ReferenceBinding) {
1230 assert(ICS.UserDefined.After.DirectBinding &&
1231 "TryClassUnification should never generate indirect ref bindings");
1232 return Self.CheckReferenceInit(E, Self.Context.getLValueReferenceType(
1235 if (Self.PerformImplicitConversion(E, TargetType(ICS), ICS, "converting"))
1240 /// \brief Check the operands of ?: under C++ semantics.
1242 /// See C++ [expr.cond]. Note that LHS is never null, even for the GNU x ?: y
1243 /// extension. In this case, LHS == Cond. (But they're not aliases.)
1244 QualType Sema::CXXCheckConditionalOperands(Expr *&Cond, Expr *&LHS, Expr *&RHS,
1245 SourceLocation QuestionLoc) {
1246 // FIXME: Handle C99's complex types, vector types, block pointers and Obj-C++
1247 // interface pointers.
1250 // The first expression is contextually converted to bool.
1251 if (!Cond->isTypeDependent()) {
1252 if (CheckCXXBooleanCondition(Cond))
1256 // Either of the arguments dependent?
1257 if (LHS->isTypeDependent() || RHS->isTypeDependent())
1258 return Context.DependentTy;
1261 // If either the second or the third operand has type (cv) void, ...
1262 QualType LTy = LHS->getType();
1263 QualType RTy = RHS->getType();
1264 bool LVoid = LTy->isVoidType();
1265 bool RVoid = RTy->isVoidType();
1266 if (LVoid || RVoid) {
1267 // ... then the [l2r] conversions are performed on the second and third
1269 DefaultFunctionArrayConversion(LHS);
1270 DefaultFunctionArrayConversion(RHS);
1271 LTy = LHS->getType();
1272 RTy = RHS->getType();
1274 // ... and one of the following shall hold:
1275 // -- The second or the third operand (but not both) is a throw-
1276 // expression; the result is of the type of the other and is an rvalue.
1277 bool LThrow = isa<CXXThrowExpr>(LHS);
1278 bool RThrow = isa<CXXThrowExpr>(RHS);
1279 if (LThrow && !RThrow)
1281 if (RThrow && !LThrow)
1284 // -- Both the second and third operands have type void; the result is of
1285 // type void and is an rvalue.
1287 return Context.VoidTy;
1289 // Neither holds, error.
1290 Diag(QuestionLoc, diag::err_conditional_void_nonvoid)
1291 << (LVoid ? RTy : LTy) << (LVoid ? 0 : 1)
1292 << LHS->getSourceRange() << RHS->getSourceRange();
1299 // Otherwise, if the second and third operand have different types, and
1300 // either has (cv) class type, and attempt is made to convert each of those
1301 // operands to the other.
1302 if (Context.getCanonicalType(LTy) != Context.getCanonicalType(RTy) &&
1303 (LTy->isRecordType() || RTy->isRecordType())) {
1304 ImplicitConversionSequence ICSLeftToRight, ICSRightToLeft;
1305 // These return true if a single direction is already ambiguous.
1306 if (TryClassUnification(*this, LHS, RHS, QuestionLoc, ICSLeftToRight))
1308 if (TryClassUnification(*this, RHS, LHS, QuestionLoc, ICSRightToLeft))
1311 bool HaveL2R = ICSLeftToRight.ConversionKind !=
1312 ImplicitConversionSequence::BadConversion;
1313 bool HaveR2L = ICSRightToLeft.ConversionKind !=
1314 ImplicitConversionSequence::BadConversion;
1315 // If both can be converted, [...] the program is ill-formed.
1316 if (HaveL2R && HaveR2L) {
1317 Diag(QuestionLoc, diag::err_conditional_ambiguous)
1318 << LTy << RTy << LHS->getSourceRange() << RHS->getSourceRange();
1322 // If exactly one conversion is possible, that conversion is applied to
1323 // the chosen operand and the converted operands are used in place of the
1324 // original operands for the remainder of this section.
1326 if (ConvertForConditional(*this, LHS, ICSLeftToRight))
1328 LTy = LHS->getType();
1329 } else if (HaveR2L) {
1330 if (ConvertForConditional(*this, RHS, ICSRightToLeft))
1332 RTy = RHS->getType();
1337 // If the second and third operands are lvalues and have the same type,
1338 // the result is of that type [...]
1339 bool Same = Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy);
1340 if (Same && LHS->isLvalue(Context) == Expr::LV_Valid &&
1341 RHS->isLvalue(Context) == Expr::LV_Valid)
1345 // Otherwise, the result is an rvalue. If the second and third operands
1346 // do not have the same type, and either has (cv) class type, ...
1347 if (!Same && (LTy->isRecordType() || RTy->isRecordType())) {
1348 // ... overload resolution is used to determine the conversions (if any)
1349 // to be applied to the operands. If the overload resolution fails, the
1350 // program is ill-formed.
1351 if (FindConditionalOverload(*this, LHS, RHS, QuestionLoc))
1356 // LValue-to-rvalue, array-to-pointer, and function-to-pointer standard
1357 // conversions are performed on the second and third operands.
1358 DefaultFunctionArrayConversion(LHS);
1359 DefaultFunctionArrayConversion(RHS);
1360 LTy = LHS->getType();
1361 RTy = RHS->getType();
1363 // After those conversions, one of the following shall hold:
1364 // -- The second and third operands have the same type; the result
1366 if (Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy))
1369 // -- The second and third operands have arithmetic or enumeration type;
1370 // the usual arithmetic conversions are performed to bring them to a
1371 // common type, and the result is of that type.
1372 if (LTy->isArithmeticType() && RTy->isArithmeticType()) {
1373 UsualArithmeticConversions(LHS, RHS);
1374 return LHS->getType();
1377 // -- The second and third operands have pointer type, or one has pointer
1378 // type and the other is a null pointer constant; pointer conversions
1379 // and qualification conversions are performed to bring them to their
1380 // composite pointer type. The result is of the composite pointer type.
1381 QualType Composite = FindCompositePointerType(LHS, RHS);
1382 if (!Composite.isNull())
1385 // Fourth bullet is same for pointers-to-member. However, the possible
1386 // conversions are far more limited: we have null-to-pointer, upcast of
1387 // containing class, and second-level cv-ness.
1388 // cv-ness is not a union, but must match one of the two operands. (Which,
1389 // frankly, is stupid.)
1390 const MemberPointerType *LMemPtr = LTy->getAsMemberPointerType();
1391 const MemberPointerType *RMemPtr = RTy->getAsMemberPointerType();
1392 if (LMemPtr && RHS->isNullPointerConstant(Context)) {
1393 ImpCastExprToType(RHS, LTy);
1396 if (RMemPtr && LHS->isNullPointerConstant(Context)) {
1397 ImpCastExprToType(LHS, RTy);
1400 if (LMemPtr && RMemPtr) {
1401 QualType LPointee = LMemPtr->getPointeeType();
1402 QualType RPointee = RMemPtr->getPointeeType();
1403 // First, we check that the unqualified pointee type is the same. If it's
1404 // not, there's no conversion that will unify the two pointers.
1405 if (Context.getCanonicalType(LPointee).getUnqualifiedType() ==
1406 Context.getCanonicalType(RPointee).getUnqualifiedType()) {
1407 // Second, we take the greater of the two cv qualifications. If neither
1408 // is greater than the other, the conversion is not possible.
1409 unsigned Q = LPointee.getCVRQualifiers() | RPointee.getCVRQualifiers();
1410 if (Q == LPointee.getCVRQualifiers() || Q == RPointee.getCVRQualifiers()){
1411 // Third, we check if either of the container classes is derived from
1413 QualType LContainer(LMemPtr->getClass(), 0);
1414 QualType RContainer(RMemPtr->getClass(), 0);
1415 QualType MoreDerived;
1416 if (Context.getCanonicalType(LContainer) ==
1417 Context.getCanonicalType(RContainer))
1418 MoreDerived = LContainer;
1419 else if (IsDerivedFrom(LContainer, RContainer))
1420 MoreDerived = LContainer;
1421 else if (IsDerivedFrom(RContainer, LContainer))
1422 MoreDerived = RContainer;
1424 if (!MoreDerived.isNull()) {
1425 // The type 'Q Pointee (MoreDerived::*)' is the common type.
1426 // We don't use ImpCastExprToType here because this could still fail
1427 // for ambiguous or inaccessible conversions.
1428 QualType Common = Context.getMemberPointerType(
1429 LPointee.getQualifiedType(Q), MoreDerived.getTypePtr());
1430 if (PerformImplicitConversion(LHS, Common, "converting"))
1432 if (PerformImplicitConversion(RHS, Common, "converting"))
1440 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands)
1441 << LHS->getType() << RHS->getType()
1442 << LHS->getSourceRange() << RHS->getSourceRange();
1446 /// \brief Find a merged pointer type and convert the two expressions to it.
1448 /// This finds the composite pointer type for @p E1 and @p E2 according to
1449 /// C++0x 5.9p2. It converts both expressions to this type and returns it.
1450 /// It does not emit diagnostics.
1451 QualType Sema::FindCompositePointerType(Expr *&E1, Expr *&E2) {
1452 assert(getLangOptions().CPlusPlus && "This function assumes C++");
1453 QualType T1 = E1->getType(), T2 = E2->getType();
1454 if(!T1->isPointerType() && !T2->isPointerType())
1458 // Pointer conversions and qualification conversions are performed on
1459 // pointer operands to bring them to their composite pointer type. If
1460 // one operand is a null pointer constant, the composite pointer type is
1461 // the type of the other operand.
1462 if (E1->isNullPointerConstant(Context)) {
1463 ImpCastExprToType(E1, T2);
1466 if (E2->isNullPointerConstant(Context)) {
1467 ImpCastExprToType(E2, T1);
1470 // Now both have to be pointers.
1471 if(!T1->isPointerType() || !T2->isPointerType())
1474 // Otherwise, of one of the operands has type "pointer to cv1 void," then
1475 // the other has type "pointer to cv2 T" and the composite pointer type is
1476 // "pointer to cv12 void," where cv12 is the union of cv1 and cv2.
1477 // Otherwise, the composite pointer type is a pointer type similar to the
1478 // type of one of the operands, with a cv-qualification signature that is
1479 // the union of the cv-qualification signatures of the operand types.
1480 // In practice, the first part here is redundant; it's subsumed by the second.
1481 // What we do here is, we build the two possible composite types, and try the
1482 // conversions in both directions. If only one works, or if the two composite
1483 // types are the same, we have succeeded.
1484 llvm::SmallVector<unsigned, 4> QualifierUnion;
1485 QualType Composite1 = T1, Composite2 = T2;
1486 const PointerType *Ptr1, *Ptr2;
1487 while ((Ptr1 = Composite1->getAsPointerType()) &&
1488 (Ptr2 = Composite2->getAsPointerType())) {
1489 Composite1 = Ptr1->getPointeeType();
1490 Composite2 = Ptr2->getPointeeType();
1491 QualifierUnion.push_back(
1492 Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers());
1494 // Rewrap the composites as pointers with the union CVRs.
1495 for (llvm::SmallVector<unsigned, 4>::iterator I = QualifierUnion.begin(),
1496 E = QualifierUnion.end(); I != E; ++I) {
1497 Composite1 = Context.getPointerType(Composite1.getQualifiedType(*I));
1498 Composite2 = Context.getPointerType(Composite2.getQualifiedType(*I));
1501 ImplicitConversionSequence E1ToC1 = TryImplicitConversion(E1, Composite1);
1502 ImplicitConversionSequence E2ToC1 = TryImplicitConversion(E2, Composite1);
1503 ImplicitConversionSequence E1ToC2, E2ToC2;
1504 E1ToC2.ConversionKind = ImplicitConversionSequence::BadConversion;
1505 E2ToC2.ConversionKind = ImplicitConversionSequence::BadConversion;
1506 if (Context.getCanonicalType(Composite1) !=
1507 Context.getCanonicalType(Composite2)) {
1508 E1ToC2 = TryImplicitConversion(E1, Composite2);
1509 E2ToC2 = TryImplicitConversion(E2, Composite2);
1512 bool ToC1Viable = E1ToC1.ConversionKind !=
1513 ImplicitConversionSequence::BadConversion
1514 && E2ToC1.ConversionKind !=
1515 ImplicitConversionSequence::BadConversion;
1516 bool ToC2Viable = E1ToC2.ConversionKind !=
1517 ImplicitConversionSequence::BadConversion
1518 && E2ToC2.ConversionKind !=
1519 ImplicitConversionSequence::BadConversion;
1520 if (ToC1Viable && !ToC2Viable) {
1521 if (!PerformImplicitConversion(E1, Composite1, E1ToC1, "converting") &&
1522 !PerformImplicitConversion(E2, Composite1, E2ToC1, "converting"))
1525 if (ToC2Viable && !ToC1Viable) {
1526 if (!PerformImplicitConversion(E1, Composite2, E1ToC2, "converting") &&
1527 !PerformImplicitConversion(E2, Composite2, E2ToC2, "converting"))
1533 Sema::OwningExprResult Sema::MaybeBindToTemporary(Expr *E) {
1534 const RecordType *RT = E->getType()->getAsRecordType();
1538 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1539 if (RD->hasTrivialDestructor())
1542 CXXTemporary *Temp = CXXTemporary::Create(Context,
1543 RD->getDestructor(Context));
1544 ExprTemporaries.push_back(Temp);
1546 // FIXME: Add the temporary to the temporaries vector.
1547 return Owned(CXXBindTemporaryExpr::Create(Context, Temp, E));
1550 // FIXME: This doesn't handle casts yet.
1551 Expr *Sema::RemoveOutermostTemporaryBinding(Expr *E) {
1552 const RecordType *RT = E->getType()->getAsRecordType();
1556 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1557 if (RD->hasTrivialDestructor())
1560 /// The expr passed in must be a CXXExprWithTemporaries.
1561 CXXExprWithTemporaries *TempExpr = dyn_cast<CXXExprWithTemporaries>(E);
1565 Expr *SubExpr = TempExpr->getSubExpr();
1566 if (CXXBindTemporaryExpr *BE = dyn_cast<CXXBindTemporaryExpr>(SubExpr)) {
1567 assert(BE->getTemporary() ==
1568 TempExpr->getTemporary(TempExpr->getNumTemporaries() - 1) &&
1569 "Found temporary is not last in list!");
1571 Expr *BindSubExpr = BE->getSubExpr();
1574 if (TempExpr->getNumTemporaries() == 1) {
1575 // There's just one temporary left, so we don't need the TempExpr node.
1576 TempExpr->Destroy(Context);
1579 TempExpr->removeLastTemporary();
1580 TempExpr->setSubExpr(BindSubExpr);
1581 BE->Destroy(Context);
1587 // FIXME: We might need to handle other expressions here.
1591 Expr *Sema::MaybeCreateCXXExprWithTemporaries(Expr *SubExpr,
1592 bool DestroyTemps) {
1593 assert(SubExpr && "sub expression can't be null!");
1595 if (ExprTemporaries.empty())
1598 Expr *E = CXXExprWithTemporaries::Create(Context, SubExpr,
1599 &ExprTemporaries[0],
1600 ExprTemporaries.size(),
1602 ExprTemporaries.clear();
1607 Sema::OwningExprResult Sema::ActOnFinishFullExpr(ExprArg Arg) {
1608 Expr *FullExpr = Arg.takeAs<Expr>();
1610 FullExpr = MaybeCreateCXXExprWithTemporaries(FullExpr);
1612 return Owned(FullExpr);