1 //===----- CGCXXABI.cpp - Interface to C++ ABIs -----------------*- C++ -*-===//
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 provides an abstract class for C++ code generation. Concrete subclasses
11 // of this implement code generation for specific C++ ABIs.
13 //===----------------------------------------------------------------------===//
17 using namespace clang;
18 using namespace CodeGen;
20 CGCXXABI::~CGCXXABI() { }
22 static void ErrorUnsupportedABI(CodeGenFunction &CGF,
24 DiagnosticsEngine &Diags = CGF.CGM.getDiags();
25 unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
26 "cannot yet compile %1 in this ABI");
27 Diags.Report(CGF.getContext().getFullLoc(CGF.CurCodeDecl->getLocation()),
32 static llvm::Constant *GetBogusMemberPointer(CodeGenModule &CGM,
34 return llvm::Constant::getNullValue(CGM.getTypes().ConvertType(T));
38 CGCXXABI::ConvertMemberPointerType(const MemberPointerType *MPT) {
39 return CGM.getTypes().ConvertType(CGM.getContext().getPointerDiffType());
42 llvm::Value *CGCXXABI::EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF,
45 const MemberPointerType *MPT) {
46 ErrorUnsupportedABI(CGF, "calls through member pointers");
48 const FunctionProtoType *FPT =
49 MPT->getPointeeType()->getAs<FunctionProtoType>();
50 const CXXRecordDecl *RD =
51 cast<CXXRecordDecl>(MPT->getClass()->getAs<RecordType>()->getDecl());
52 llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(
53 CGM.getTypes().arrangeCXXMethodType(RD, FPT));
54 return llvm::Constant::getNullValue(FTy->getPointerTo());
57 llvm::Value *CGCXXABI::EmitMemberDataPointerAddress(CodeGenFunction &CGF,
60 const MemberPointerType *MPT) {
61 ErrorUnsupportedABI(CGF, "loads of member pointers");
62 llvm::Type *Ty = CGF.ConvertType(MPT->getPointeeType())->getPointerTo();
63 return llvm::Constant::getNullValue(Ty);
66 llvm::Value *CGCXXABI::EmitMemberPointerConversion(CodeGenFunction &CGF,
69 ErrorUnsupportedABI(CGF, "member function pointer conversions");
70 return GetBogusMemberPointer(CGM, E->getType());
73 llvm::Constant *CGCXXABI::EmitMemberPointerConversion(const CastExpr *E,
74 llvm::Constant *Src) {
75 return GetBogusMemberPointer(CGM, E->getType());
79 CGCXXABI::EmitMemberPointerComparison(CodeGenFunction &CGF,
82 const MemberPointerType *MPT,
84 ErrorUnsupportedABI(CGF, "member function pointer comparison");
85 return CGF.Builder.getFalse();
89 CGCXXABI::EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
91 const MemberPointerType *MPT) {
92 ErrorUnsupportedABI(CGF, "member function pointer null testing");
93 return CGF.Builder.getFalse();
97 CGCXXABI::EmitNullMemberPointer(const MemberPointerType *MPT) {
98 return GetBogusMemberPointer(CGM, QualType(MPT, 0));
101 llvm::Constant *CGCXXABI::EmitMemberPointer(const CXXMethodDecl *MD) {
102 return GetBogusMemberPointer(CGM,
103 CGM.getContext().getMemberPointerType(MD->getType(),
104 MD->getParent()->getTypeForDecl()));
107 llvm::Constant *CGCXXABI::EmitMemberDataPointer(const MemberPointerType *MPT,
109 return GetBogusMemberPointer(CGM, QualType(MPT, 0));
112 llvm::Constant *CGCXXABI::EmitMemberPointer(const APValue &MP, QualType MPT) {
113 return GetBogusMemberPointer(CGM, MPT);
116 bool CGCXXABI::isZeroInitializable(const MemberPointerType *MPT) {
121 void CGCXXABI::BuildThisParam(CodeGenFunction &CGF, FunctionArgList ¶ms) {
122 const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl());
124 // FIXME: I'm not entirely sure I like using a fake decl just for code
125 // generation. Maybe we can come up with a better way?
126 ImplicitParamDecl *ThisDecl
127 = ImplicitParamDecl::Create(CGM.getContext(), 0, MD->getLocation(),
128 &CGM.getContext().Idents.get("this"),
129 MD->getThisType(CGM.getContext()));
130 params.push_back(ThisDecl);
131 getThisDecl(CGF) = ThisDecl;
134 void CGCXXABI::EmitThisParam(CodeGenFunction &CGF) {
135 /// Initialize the 'this' slot.
136 assert(getThisDecl(CGF) && "no 'this' variable for function");
138 = CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(getThisDecl(CGF)),
142 void CGCXXABI::EmitReturnFromThunk(CodeGenFunction &CGF,
143 RValue RV, QualType ResultType) {
144 CGF.EmitReturnOfRValue(RV, ResultType);
147 CharUnits CGCXXABI::GetArrayCookieSize(const CXXNewExpr *expr) {
148 return CharUnits::Zero();
151 llvm::Value *CGCXXABI::InitializeArrayCookie(CodeGenFunction &CGF,
153 llvm::Value *NumElements,
154 const CXXNewExpr *expr,
155 QualType ElementType) {
156 // Should never be called.
157 ErrorUnsupportedABI(CGF, "array cookie initialization");
161 void CGCXXABI::ReadArrayCookie(CodeGenFunction &CGF, llvm::Value *Ptr,
162 const CXXDeleteExpr *expr, QualType ElementType,
163 llvm::Value *&NumElements,
164 llvm::Value *&AllocPtr, CharUnits &CookieSize) {
165 ErrorUnsupportedABI(CGF, "array cookie reading");
167 // This should be enough to avoid assertions.
169 AllocPtr = llvm::Constant::getNullValue(CGF.Builder.getInt8PtrTy());
170 CookieSize = CharUnits::Zero();
173 void CGCXXABI::EmitGuardedInit(CodeGenFunction &CGF,
175 llvm::GlobalVariable *GV,
177 ErrorUnsupportedABI(CGF, "static local variable initialization");
180 /// Returns the adjustment, in bytes, required for the given
181 /// member-pointer operation. Returns null if no adjustment is
183 llvm::Constant *CGCXXABI::getMemberPointerAdjustment(const CastExpr *E) {
184 assert(E->getCastKind() == CK_DerivedToBaseMemberPointer ||
185 E->getCastKind() == CK_BaseToDerivedMemberPointer);
187 QualType derivedType;
188 if (E->getCastKind() == CK_DerivedToBaseMemberPointer)
189 derivedType = E->getSubExpr()->getType();
191 derivedType = E->getType();
193 const CXXRecordDecl *derivedClass =
194 derivedType->castAs<MemberPointerType>()->getClass()->getAsCXXRecordDecl();
196 return CGM.GetNonVirtualBaseClassOffset(derivedClass,