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/CGCXXABI.h b/lib/CodeGen/CGCXXABI.h
index e4d9e5f..6629e04 100644
--- a/lib/CodeGen/CGCXXABI.h
+++ b/lib/CodeGen/CGCXXABI.h
@@ -97,8 +97,12 @@
return *MangleCtx;
}
- /// Returns true if the given instance method is one of the
- /// kinds that the ABI says returns 'this'.
+ /// Returns true if the given constructor or destructor is one of the
+ /// kinds that the ABI says returns 'this' (only applies when called
+ /// non-virtually for destructors).
+ ///
+ /// There currently is no way to indicate if a destructor returns 'this'
+ /// when called virtually, and code generation does not support the case.
virtual bool HasThisReturn(GlobalDecl GD) const { return false; }
/// Returns true if the given record type should be returned indirectly.
@@ -214,10 +218,10 @@
const CXXRecordDecl *BaseClassDecl) = 0;
/// Build the signature of the given constructor variant by adding
- /// any required parameters. For convenience, ResTy has been
- /// initialized to 'void', and ArgTys has been initialized with the
- /// type of 'this' (although this may be changed by the ABI) and
- /// will have the formal parameters added to it afterwards.
+ /// any required parameters. For convenience, ArgTys has been initialized
+ /// with the type of 'this' and ResTy has been initialized with the type of
+ /// 'this' if HasThisReturn(GlobalDecl(Ctor, T)) is true or 'void' otherwise
+ /// (although both may be changed by the ABI).
///
/// If there are ever any ABIs where the implicit parameters are
/// intermixed with the formal parameters, we can address those
@@ -231,9 +235,10 @@
const CXXRecordDecl *RD);
/// Build the signature of the given destructor variant by adding
- /// any required parameters. For convenience, ResTy has been
- /// initialized to 'void' and ArgTys has been initialized with the
- /// type of 'this' (although this may be changed by the ABI).
+ /// any required parameters. For convenience, ArgTys has been initialized
+ /// with the type of 'this' and ResTy has been initialized with the type of
+ /// 'this' if HasThisReturn(GlobalDecl(Dtor, T)) is true or 'void' otherwise
+ /// (although both may be changed by the ABI).
virtual void BuildDestructorSignature(const CXXDestructorDecl *Dtor,
CXXDtorType T,
CanQualType &ResTy,
@@ -244,7 +249,8 @@
/// possibly some extra data for constructors and destructors.
///
/// ABIs may also choose to override the return type, which has been
- /// initialized with the formal return type of the function.
+ /// initialized with the type of 'this' if HasThisReturn(CGF.CurGD) is true or
+ /// the formal return type of the function otherwise.
virtual void BuildInstanceFunctionParams(CodeGenFunction &CGF,
QualType &ResTy,
FunctionArgList &Params) = 0;
@@ -253,21 +259,20 @@
virtual void EmitInstanceFunctionProlog(CodeGenFunction &CGF) = 0;
/// Emit the constructor call. Return the function that is called.
- virtual llvm::Value *EmitConstructorCall(CodeGenFunction &CGF,
+ virtual void EmitConstructorCall(CodeGenFunction &CGF,
const CXXConstructorDecl *D,
- CXXCtorType Type, bool ForVirtualBase,
- bool Delegating,
+ CXXCtorType Type,
+ bool ForVirtualBase, bool Delegating,
llvm::Value *This,
CallExpr::const_arg_iterator ArgBeg,
CallExpr::const_arg_iterator ArgEnd) = 0;
/// Emit the ABI-specific virtual destructor call.
- virtual RValue EmitVirtualDestructorCall(CodeGenFunction &CGF,
- const CXXDestructorDecl *Dtor,
- CXXDtorType DtorType,
- SourceLocation CallLoc,
- ReturnValueSlot ReturnValue,
- llvm::Value *This) = 0;
+ virtual void EmitVirtualDestructorCall(CodeGenFunction &CGF,
+ const CXXDestructorDecl *Dtor,
+ CXXDtorType DtorType,
+ SourceLocation CallLoc,
+ llvm::Value *This) = 0;
/// Emit any tables needed to implement virtual inheritance. For Itanium,
/// this emits virtual table tables. For the MSVC++ ABI, this emits virtual
diff --git a/lib/CodeGen/CGCall.cpp b/lib/CodeGen/CGCall.cpp
index cb5c78a..7d60773 100644
--- a/lib/CodeGen/CGCall.cpp
+++ b/lib/CodeGen/CGCall.cpp
@@ -200,7 +200,10 @@
CXXCtorType ctorKind) {
SmallVector<CanQualType, 16> argTypes;
argTypes.push_back(GetThisType(Context, D->getParent()));
- CanQualType resultType = Context.VoidTy;
+
+ GlobalDecl GD(D, ctorKind);
+ CanQualType resultType =
+ TheCXXABI.HasThisReturn(GD) ? argTypes.front() : Context.VoidTy;
TheCXXABI.BuildConstructorSignature(D, ctorKind, resultType, argTypes);
@@ -225,7 +228,10 @@
CXXDtorType dtorKind) {
SmallVector<CanQualType, 2> argTypes;
argTypes.push_back(GetThisType(Context, D->getParent()));
- CanQualType resultType = Context.VoidTy;
+
+ GlobalDecl GD(D, dtorKind);
+ CanQualType resultType =
+ TheCXXABI.HasThisReturn(GD) ? argTypes.front() : Context.VoidTy;
TheCXXABI.BuildDestructorSignature(D, dtorKind, resultType, argTypes);
@@ -1633,18 +1639,6 @@
return store;
}
-/// Check whether 'this' argument of a callsite matches 'this' of the caller.
-static bool checkThisPointer(llvm::Value *ThisArg, llvm::Value *This) {
- if (ThisArg == This)
- return true;
- // Check whether ThisArg is a bitcast of This.
- llvm::BitCastInst *Bitcast;
- if ((Bitcast = dyn_cast<llvm::BitCastInst>(ThisArg)) &&
- Bitcast->getOperand(0) == This)
- return true;
- return false;
-}
-
void CodeGenFunction::EmitFunctionEpilog(const CGFunctionInfo &FI,
bool EmitRetDbgLoc) {
// Functions with no result always return void.
@@ -1741,19 +1735,6 @@
llvm_unreachable("Invalid ABI kind for return argument");
}
- // If this function returns 'this', the last instruction is a CallInst
- // that returns 'this', and 'this' argument of the CallInst points to
- // the same object as CXXThisValue, use the return value from the CallInst.
- // We will not need to keep 'this' alive through the callsite. It also enables
- // optimizations in the backend, such as tail call optimization.
- if (CalleeWithThisReturn && CGM.getCXXABI().HasThisReturn(CurGD)) {
- llvm::BasicBlock *IP = Builder.GetInsertBlock();
- llvm::CallInst *Callsite;
- if (!IP->empty() && (Callsite = dyn_cast<llvm::CallInst>(&IP->back())) &&
- Callsite->getCalledFunction() == CalleeWithThisReturn &&
- checkThisPointer(Callsite->getOperand(0), CXXThisValue))
- RV = Builder.CreateBitCast(Callsite, RetAI.getCoerceToType());
- }
llvm::Instruction *Ret = RV ? Builder.CreateRet(RV) : Builder.CreateRetVoid();
if (!RetDbgLoc.isUnknown())
Ret->setDebugLoc(RetDbgLoc);
diff --git a/lib/CodeGen/CGClass.cpp b/lib/CodeGen/CGClass.cpp
index 9b34ece..c522059 100644
--- a/lib/CodeGen/CGClass.cpp
+++ b/lib/CodeGen/CGClass.cpp
@@ -1662,11 +1662,8 @@
}
// Non-trivial constructors are handled in an ABI-specific manner.
- llvm::Value *Callee = CGM.getCXXABI().EmitConstructorCall(*this, D, Type,
- ForVirtualBase, Delegating, This, ArgBeg, ArgEnd);
- if (CGM.getCXXABI().HasThisReturn(CurGD) &&
- CGM.getCXXABI().HasThisReturn(GlobalDecl(D, Type)))
- CalleeWithThisReturn = Callee;
+ CGM.getCXXABI().EmitConstructorCall(*this, D, Type, ForVirtualBase,
+ Delegating, This, ArgBeg, ArgEnd);
}
void
@@ -1758,9 +1755,6 @@
llvm::Value *Callee = CGM.GetAddrOfCXXConstructor(Ctor, CtorType);
EmitCall(CGM.getTypes().arrangeCXXConstructorDeclaration(Ctor, CtorType),
Callee, ReturnValueSlot(), DelegateArgs, Ctor);
- if (CGM.getCXXABI().HasThisReturn(CurGD) &&
- CGM.getCXXABI().HasThisReturn(GlobalDecl(Ctor, CtorType)))
- CalleeWithThisReturn = Callee;
}
namespace {
@@ -1827,9 +1821,6 @@
EmitCXXMemberCall(DD, SourceLocation(), Callee, ReturnValueSlot(), This,
VTT, getContext().getPointerType(getContext().VoidPtrTy),
0, 0);
- if (CGM.getCXXABI().HasThisReturn(CurGD) &&
- CGM.getCXXABI().HasThisReturn(GlobalDecl(DD, Type)))
- CalleeWithThisReturn = Callee;
}
namespace {
diff --git a/lib/CodeGen/CGExprCXX.cpp b/lib/CodeGen/CGExprCXX.cpp
index 60a70f8..438657a 100644
--- a/lib/CodeGen/CGExprCXX.cpp
+++ b/lib/CodeGen/CGExprCXX.cpp
@@ -280,16 +280,15 @@
// We also don't emit a virtual call if the base expression has a record type
// because then we know what the type is.
bool UseVirtualCall = CanUseVirtualCall && !DevirtualizedMethod;
-
llvm::Value *Callee;
+
if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(MD)) {
+ assert(CE->arg_begin() == CE->arg_end() &&
+ "Destructor shouldn't have explicit parameters");
+ assert(ReturnValue.isNull() && "Destructor shouldn't have return value");
if (UseVirtualCall) {
- assert(CE->arg_begin() == CE->arg_end() &&
- "Virtual destructor shouldn't have explicit parameters");
- return CGM.getCXXABI().EmitVirtualDestructorCall(*this, Dtor,
- Dtor_Complete,
- CE->getExprLoc(),
- ReturnValue, This);
+ CGM.getCXXABI().EmitVirtualDestructorCall(*this, Dtor, Dtor_Complete,
+ CE->getExprLoc(), This);
} else {
if (getLangOpts().AppleKext &&
MD->isVirtual() &&
@@ -302,12 +301,16 @@
cast<CXXDestructorDecl>(DevirtualizedMethod);
Callee = CGM.GetAddrOfFunction(GlobalDecl(DDtor, Dtor_Complete), Ty);
}
+ EmitCXXMemberCall(MD, CE->getExprLoc(), Callee, ReturnValue, This,
+ /*ImplicitParam=*/0, QualType(), 0, 0);
}
- } else if (const CXXConstructorDecl *Ctor =
- dyn_cast<CXXConstructorDecl>(MD)) {
+ return RValue::get(0);
+ }
+
+ if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(MD)) {
Callee = CGM.GetAddrOfFunction(GlobalDecl(Ctor, Ctor_Complete), Ty);
} else if (UseVirtualCall) {
- Callee = BuildVirtualCall(MD, This, Ty);
+ Callee = BuildVirtualCall(MD, This, Ty);
} else {
if (getLangOpts().AppleKext &&
MD->isVirtual() &&
@@ -1413,8 +1416,7 @@
// FIXME: Provide a source location here.
CXXDtorType DtorType = UseGlobalDelete ? Dtor_Complete : Dtor_Deleting;
CGF.CGM.getCXXABI().EmitVirtualDestructorCall(CGF, Dtor, DtorType,
- SourceLocation(),
- ReturnValueSlot(), Ptr);
+ SourceLocation(), Ptr);
if (UseGlobalDelete) {
CGF.PopCleanupBlock();
diff --git a/lib/CodeGen/CGVTables.cpp b/lib/CodeGen/CGVTables.cpp
index e15639d..9c4a5e0 100644
--- a/lib/CodeGen/CGVTables.cpp
+++ b/lib/CodeGen/CGVTables.cpp
@@ -287,8 +287,9 @@
GlobalDecl GD, const ThunkInfo &Thunk) {
const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>();
- QualType ResultType = FPT->getResultType();
QualType ThisType = MD->getThisType(getContext());
+ QualType ResultType =
+ CGM.getCXXABI().HasThisReturn(GD) ? ThisType : FPT->getResultType();
FunctionArgList FunctionArgs;
diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index c6b498c..bea13d4 100644
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -42,8 +42,7 @@
AutoreleaseResult(false), BlockInfo(0), BlockPointer(0),
LambdaThisCaptureField(0), NormalCleanupDest(0), NextCleanupDestIndex(1),
FirstBlockInfo(0), EHResumeBlock(0), ExceptionSlot(0), EHSelectorSlot(0),
- DebugInfo(0), DisableDebugInfo(false), CalleeWithThisReturn(0),
- DidCallStackSave(false),
+ DebugInfo(0), DisableDebugInfo(false), DidCallStackSave(false),
IndirectBranch(0), SwitchInsn(0), CaseRangeBlock(0), UnreachableBlock(0),
NumReturnExprs(0), NumSimpleReturnExprs(0),
CXXABIThisDecl(0), CXXABIThisValue(0), CXXThisValue(0),
@@ -662,8 +661,12 @@
QualType ResTy = FD->getResultType();
CurGD = GD;
- if (isa<CXXMethodDecl>(FD) && cast<CXXMethodDecl>(FD)->isInstance())
+ const CXXMethodDecl *MD;
+ if ((MD = dyn_cast<CXXMethodDecl>(FD)) && MD->isInstance()) {
+ if (CGM.getCXXABI().HasThisReturn(GD))
+ ResTy = MD->getThisType(getContext());
CGM.getCXXABI().BuildInstanceFunctionParams(*this, ResTy, Args);
+ }
for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i)
Args.push_back(FD->getParamDecl(i));
@@ -672,10 +675,6 @@
if (Stmt *Body = FD->getBody()) BodyRange = Body->getSourceRange();
CurEHLocation = BodyRange.getEnd();
- // CalleeWithThisReturn keeps track of the last callee inside this function
- // that returns 'this'. Before starting the function, we set it to null.
- CalleeWithThisReturn = 0;
-
// Emit the standard function prologue.
StartFunction(GD, ResTy, Fn, FnInfo, Args, BodyRange.getBegin());
@@ -727,9 +726,6 @@
// Emit the standard function epilogue.
FinishFunction(BodyRange.getEnd());
- // CalleeWithThisReturn keeps track of the last callee inside this function
- // that returns 'this'. After finishing the function, we set it to null.
- CalleeWithThisReturn = 0;
// If we haven't marked the function nothrow through other means, do
// a quick pass now to see if we can.
diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index 8b6842d..a9ed49e 100644
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -798,10 +798,6 @@
CGDebugInfo *DebugInfo;
bool DisableDebugInfo;
- /// If the current function returns 'this', use the field to keep track of
- /// the callee that returns 'this'.
- llvm::Value *CalleeWithThisReturn;
-
/// DidCallStackSave - Whether llvm.stacksave has been called. Used to avoid
/// calling llvm.stacksave for multiple VLAs in the same scope.
bool DidCallStackSave;
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index efff4b1..3298d5a 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -722,6 +722,14 @@
if (!IsIncompleteFunction)
SetLLVMFunctionAttributes(FD, getTypes().arrangeGlobalDeclaration(GD), F);
+ if (getCXXABI().HasThisReturn(GD)) {
+ assert(!F->arg_empty() &&
+ F->arg_begin()->getType()
+ ->canLosslesslyBitCastTo(F->getReturnType()) &&
+ "unexpected this return");
+ F->addAttribute(1, llvm::Attribute::Returned);
+ }
+
// Only a few attributes are set on declarations; these may later be
// overridden by a definition.
diff --git a/lib/CodeGen/ItaniumCXXABI.cpp b/lib/CodeGen/ItaniumCXXABI.cpp
index 67174c0..279c212 100644
--- a/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/lib/CodeGen/ItaniumCXXABI.cpp
@@ -119,20 +119,17 @@
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);
@@ -170,21 +167,11 @@
public:
ARMCXXABI(CodeGen::CodeGenModule &CGM) : ItaniumCXXABI(CGM, /*ARM*/ true) {}
- void BuildConstructorSignature(const CXXConstructorDecl *Ctor,
- CXXCtorType T,
- CanQualType &ResTy,
- SmallVectorImpl<CanQualType> &ArgTys);
-
- void BuildDestructorSignature(const CXXDestructorDecl *Dtor,
- CXXDtorType T,
- CanQualType &ResTy,
- SmallVectorImpl<CanQualType> &ArgTys);
-
- void BuildInstanceFunctionParams(CodeGenFunction &CGF,
- QualType &ResTy,
- FunctionArgList &Params);
-
- void EmitInstanceFunctionProlog(CodeGenFunction &CGF);
+ bool HasThisReturn(GlobalDecl GD) const {
+ return (isa<CXXConstructorDecl>(GD.getDecl()) || (
+ isa<CXXDestructorDecl>(GD.getDecl()) &&
+ GD.getDtorType() != Dtor_Deleting));
+ }
void EmitReturnFromThunk(CodeGenFunction &CGF, RValue RV, QualType ResTy);
@@ -196,15 +183,6 @@
QualType ElementType);
llvm::Value *readArrayCookieImpl(CodeGenFunction &CGF, llvm::Value *allocPtr,
CharUnits cookieSize);
-
- /// \brief Returns true if the given instance method is one of the
- /// kinds that the ARM ABI says returns 'this'.
- bool HasThisReturn(GlobalDecl GD) const {
- const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(GD.getDecl());
- if (!MD) return false;
- return ((isa<CXXDestructorDecl>(MD) && GD.getDtorType() != Dtor_Deleting) ||
- (isa<CXXConstructorDecl>(MD)));
- }
};
}
@@ -759,22 +737,14 @@
SmallVectorImpl<CanQualType> &ArgTys) {
ASTContext &Context = getContext();
- // 'this' is already there.
+ // 'this' parameter is already there, as well as 'this' return if
+ // HasThisReturn(GlobalDecl(Ctor, Type)) is true
// Check if we need to add a VTT parameter (which has type void **).
if (Type == Ctor_Base && Ctor->getParent()->getNumVBases() != 0)
ArgTys.push_back(Context.getPointerType(Context.VoidPtrTy));
}
-/// The ARM ABI does the same as the Itanium ABI, but returns 'this'.
-void ARMCXXABI::BuildConstructorSignature(const CXXConstructorDecl *Ctor,
- CXXCtorType Type,
- CanQualType &ResTy,
- SmallVectorImpl<CanQualType> &ArgTys) {
- ItaniumCXXABI::BuildConstructorSignature(Ctor, Type, ResTy, ArgTys);
- ResTy = ArgTys[0];
-}
-
/// The generic ABI passes 'this', plus a VTT if it's destroying a
/// base subobject.
void ItaniumCXXABI::BuildDestructorSignature(const CXXDestructorDecl *Dtor,
@@ -783,25 +753,14 @@
SmallVectorImpl<CanQualType> &ArgTys) {
ASTContext &Context = getContext();
- // 'this' is already there.
+ // 'this' parameter is already there, as well as 'this' return if
+ // HasThisReturn(GlobalDecl(Dtor, Type)) is true
// Check if we need to add a VTT parameter (which has type void **).
if (Type == Dtor_Base && Dtor->getParent()->getNumVBases() != 0)
ArgTys.push_back(Context.getPointerType(Context.VoidPtrTy));
}
-/// The ARM ABI does the same as the Itanium ABI, but returns 'this'
-/// for non-deleting destructors.
-void ARMCXXABI::BuildDestructorSignature(const CXXDestructorDecl *Dtor,
- CXXDtorType Type,
- CanQualType &ResTy,
- SmallVectorImpl<CanQualType> &ArgTys) {
- ItaniumCXXABI::BuildDestructorSignature(Dtor, Type, ResTy, ArgTys);
-
- if (Type != Dtor_Deleting)
- ResTy = ArgTys[0];
-}
-
void ItaniumCXXABI::BuildInstanceFunctionParams(CodeGenFunction &CGF,
QualType &ResTy,
FunctionArgList &Params) {
@@ -825,16 +784,6 @@
}
}
-void ARMCXXABI::BuildInstanceFunctionParams(CodeGenFunction &CGF,
- QualType &ResTy,
- FunctionArgList &Params) {
- ItaniumCXXABI::BuildInstanceFunctionParams(CGF, ResTy, Params);
-
- // Return 'this' from certain constructors and destructors.
- if (HasThisReturn(CGF.CurGD))
- ResTy = Params[0]->getType();
-}
-
void ItaniumCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) {
/// Initialize the 'this' slot.
EmitThisParam(CGF);
@@ -845,21 +794,23 @@
= CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(getVTTDecl(CGF)),
"vtt");
}
-}
-void ARMCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) {
- ItaniumCXXABI::EmitInstanceFunctionProlog(CGF);
-
- /// Initialize the return slot to 'this' at the start of the
- /// function.
+ /// 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);
}
-llvm::Value *ItaniumCXXABI::EmitConstructorCall(CodeGenFunction &CGF,
+void ItaniumCXXABI::EmitConstructorCall(CodeGenFunction &CGF,
const CXXConstructorDecl *D,
- CXXCtorType Type, bool ForVirtualBase,
- bool Delegating,
+ CXXCtorType Type,
+ bool ForVirtualBase, bool Delegating,
llvm::Value *This,
CallExpr::const_arg_iterator ArgBeg,
CallExpr::const_arg_iterator ArgEnd) {
@@ -869,17 +820,15 @@
llvm::Value *Callee = CGM.GetAddrOfCXXConstructor(D, Type);
// FIXME: Provide a source location here.
- CGF.EmitCXXMemberCall(D, SourceLocation(), Callee, ReturnValueSlot(), This,
- VTT, VTTTy, ArgBeg, ArgEnd);
- return Callee;
+ CGF.EmitCXXMemberCall(D, SourceLocation(), Callee, ReturnValueSlot(),
+ This, VTT, VTTTy, ArgBeg, ArgEnd);
}
-RValue ItaniumCXXABI::EmitVirtualDestructorCall(CodeGenFunction &CGF,
- const CXXDestructorDecl *Dtor,
- CXXDtorType DtorType,
- SourceLocation CallLoc,
- ReturnValueSlot ReturnValue,
- llvm::Value *This) {
+void ItaniumCXXABI::EmitVirtualDestructorCall(CodeGenFunction &CGF,
+ const CXXDestructorDecl *Dtor,
+ CXXDtorType DtorType,
+ SourceLocation CallLoc,
+ llvm::Value *This) {
assert(DtorType == Dtor_Deleting || DtorType == Dtor_Complete);
const CGFunctionInfo *FInfo
@@ -887,8 +836,8 @@
llvm::Type *Ty = CGF.CGM.getTypes().GetFunctionType(*FInfo);
llvm::Value *Callee = CGF.BuildVirtualCall(Dtor, DtorType, This, Ty);
- return CGF.EmitCXXMemberCall(Dtor, CallLoc, Callee, ReturnValue, This,
- /*ImplicitParam=*/0, QualType(), 0, 0);
+ CGF.EmitCXXMemberCall(Dtor, CallLoc, Callee, ReturnValueSlot(), This,
+ /*ImplicitParam=*/0, QualType(), 0, 0);
}
void ItaniumCXXABI::EmitVirtualInheritanceTables(
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 &