Restore r184205 and associated commits (after commit of r185290)
This allows clang to use the backend parameter attribute 'returned' when generating 'this'-returning constructors and destructors in ARM and MSVC C++ ABIs.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185291 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MicrosoftCXXABI.cpp b/lib/CodeGen/MicrosoftCXXABI.cpp
index 929130b..f1e10db 100644
--- a/lib/CodeGen/MicrosoftCXXABI.cpp
+++ b/lib/CodeGen/MicrosoftCXXABI.cpp
@@ -30,6 +30,8 @@
public:
MicrosoftCXXABI(CodeGenModule &CGM) : CGCXXABI(CGM) {}
+ bool HasThisReturn(GlobalDecl GD) const;
+
bool isReturnTypeIndirect(const CXXRecordDecl *RD) const {
// Structures that are not C++03 PODs are always indirect.
return !RD->isPOD();
@@ -74,20 +76,17 @@
void EmitInstanceFunctionProlog(CodeGenFunction &CGF);
- llvm::Value *EmitConstructorCall(CodeGenFunction &CGF,
- const CXXConstructorDecl *D,
- CXXCtorType Type, bool ForVirtualBase,
- bool Delegating,
+ void EmitConstructorCall(CodeGenFunction &CGF,
+ const CXXConstructorDecl *D, CXXCtorType Type,
+ bool ForVirtualBase, bool Delegating,
llvm::Value *This,
CallExpr::const_arg_iterator ArgBeg,
CallExpr::const_arg_iterator ArgEnd);
-
- RValue EmitVirtualDestructorCall(CodeGenFunction &CGF,
- const CXXDestructorDecl *Dtor,
- CXXDtorType DtorType,
- SourceLocation CallLoc,
- ReturnValueSlot ReturnValue,
- llvm::Value *This);
+
+ void EmitVirtualDestructorCall(CodeGenFunction &CGF,
+ const CXXDestructorDecl *Dtor,
+ CXXDtorType DtorType, SourceLocation CallLoc,
+ llvm::Value *This);
void EmitVirtualInheritanceTables(llvm::GlobalVariable::LinkageTypes Linkage,
const CXXRecordDecl *RD);
@@ -130,7 +129,6 @@
llvm::Value *readArrayCookieImpl(CodeGenFunction &CGF,
llvm::Value *allocPtr,
CharUnits cookieSize);
- static bool needThisReturn(GlobalDecl GD);
private:
llvm::Constant *getZeroInt() {
@@ -314,19 +312,15 @@
return CGF.Builder.CreateNSWAdd(VBPtrOffset, VBPtrToNewBase);
}
-bool MicrosoftCXXABI::needThisReturn(GlobalDecl GD) {
- const CXXMethodDecl* MD = cast<CXXMethodDecl>(GD.getDecl());
- return isa<CXXConstructorDecl>(MD);
+bool MicrosoftCXXABI::HasThisReturn(GlobalDecl GD) const {
+ return isa<CXXConstructorDecl>(GD.getDecl());
}
void MicrosoftCXXABI::BuildConstructorSignature(const CXXConstructorDecl *Ctor,
CXXCtorType Type,
CanQualType &ResTy,
SmallVectorImpl<CanQualType> &ArgTys) {
- // 'this' is already in place
-
- // Ctor returns this ptr
- ResTy = ArgTys[0];
+ // 'this' parameter and 'this' return are already in place
const CXXRecordDecl *Class = Ctor->getParent();
if (Class->getNumVBases()) {
@@ -384,6 +378,7 @@
CanQualType &ResTy,
SmallVectorImpl<CanQualType> &ArgTys) {
// 'this' is already in place
+
// TODO: 'for base' flag
if (Type == Dtor_Deleting) {
@@ -404,9 +399,6 @@
QualType &ResTy,
FunctionArgList &Params) {
BuildThisParam(CGF, Params);
- if (needThisReturn(CGF.CurGD)) {
- ResTy = Params[0]->getType();
- }
ASTContext &Context = getContext();
const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl());
@@ -431,9 +423,17 @@
void MicrosoftCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) {
EmitThisParam(CGF);
- if (needThisReturn(CGF.CurGD)) {
+
+ /// If this is a function that the ABI specifies returns 'this', initialize
+ /// the return slot to 'this' at the start of the function.
+ ///
+ /// Unlike the setting of return types, this is done within the ABI
+ /// implementation instead of by clients of CGCXXABI because:
+ /// 1) getThisValue is currently protected
+ /// 2) in theory, an ABI could implement 'this' returns some other way;
+ /// HasThisReturn only specifies a contract, not the implementation
+ if (HasThisReturn(CGF.CurGD))
CGF.Builder.CreateStore(getThisValue(CGF), CGF.ReturnValue);
- }
const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl());
if (isa<CXXConstructorDecl>(MD) && MD->getParent()->getNumVBases()) {
@@ -455,9 +455,10 @@
}
}
-llvm::Value *MicrosoftCXXABI::EmitConstructorCall(CodeGenFunction &CGF,
+void MicrosoftCXXABI::EmitConstructorCall(CodeGenFunction &CGF,
const CXXConstructorDecl *D,
- CXXCtorType Type, bool ForVirtualBase,
+ CXXCtorType Type,
+ bool ForVirtualBase,
bool Delegating,
llvm::Value *This,
CallExpr::const_arg_iterator ArgBeg,
@@ -474,17 +475,14 @@
// FIXME: Provide a source location here.
CGF.EmitCXXMemberCall(D, SourceLocation(), Callee, ReturnValueSlot(), This,
- ImplicitParam, ImplicitParamTy,
- ArgBeg, ArgEnd);
- return Callee;
+ ImplicitParam, ImplicitParamTy, ArgBeg, ArgEnd);
}
-RValue MicrosoftCXXABI::EmitVirtualDestructorCall(CodeGenFunction &CGF,
- const CXXDestructorDecl *Dtor,
- CXXDtorType DtorType,
- SourceLocation CallLoc,
- ReturnValueSlot ReturnValue,
- llvm::Value *This) {
+void MicrosoftCXXABI::EmitVirtualDestructorCall(CodeGenFunction &CGF,
+ const CXXDestructorDecl *Dtor,
+ CXXDtorType DtorType,
+ SourceLocation CallLoc,
+ llvm::Value *This) {
assert(DtorType == Dtor_Deleting || DtorType == Dtor_Complete);
// We have only one destructor in the vftable but can get both behaviors
@@ -499,8 +497,8 @@
= llvm::ConstantInt::get(llvm::IntegerType::getInt1Ty(CGF.getLLVMContext()),
DtorType == Dtor_Deleting);
- return CGF.EmitCXXMemberCall(Dtor, CallLoc, Callee, ReturnValue, This,
- ImplicitParam, Context.BoolTy, 0, 0);
+ CGF.EmitCXXMemberCall(Dtor, CallLoc, Callee, ReturnValueSlot(), This,
+ ImplicitParam, Context.BoolTy, 0, 0);
}
const VBTableVector &