Abstract out virtual calls and virtual function prologue code generation; implement them for -cxx-abi microsoft
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188870 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MicrosoftCXXABI.cpp b/lib/CodeGen/MicrosoftCXXABI.cpp
index b2c9ef0..79f142e 100644
--- a/lib/CodeGen/MicrosoftCXXABI.cpp
+++ b/lib/CodeGen/MicrosoftCXXABI.cpp
@@ -113,10 +113,34 @@
void EmitCXXDestructors(const CXXDestructorDecl *D);
+ const CXXRecordDecl *getThisArgumentTypeForMethod(const CXXMethodDecl *MD) {
+ MD = MD->getCanonicalDecl();
+ if (MD->isVirtual() && !isa<CXXDestructorDecl>(MD)) {
+ MicrosoftVFTableContext::MethodVFTableLocation ML =
+ CGM.getVFTableContext().getMethodVFTableLocation(MD);
+ // The vbases might be ordered differently in the final overrider object
+ // and the complete object, so the "this" argument may sometimes point to
+ // memory that has no particular type (e.g. past the complete object).
+ // In this case, we just use a generic pointer type.
+ // FIXME: might want to have a more precise type in the non-virtual
+ // multiple inheritance case.
+ if (ML.VBase || !ML.VFTableOffset.isZero())
+ return 0;
+ }
+ return MD->getParent();
+ }
+
+ llvm::Value *adjustThisArgumentForVirtualCall(CodeGenFunction &CGF,
+ GlobalDecl GD,
+ llvm::Value *This);
+
void BuildInstanceFunctionParams(CodeGenFunction &CGF,
QualType &ResTy,
FunctionArgList &Params);
+ llvm::Value *adjustThisParameterInVirtualFunctionPrologue(
+ CodeGenFunction &CGF, GlobalDecl GD, llvm::Value *This);
+
void EmitInstanceFunctionProlog(CodeGenFunction &CGF);
void EmitConstructorCall(CodeGenFunction &CGF,
@@ -125,7 +149,10 @@
llvm::Value *This,
CallExpr::const_arg_iterator ArgBeg,
CallExpr::const_arg_iterator ArgEnd);
-
+
+ llvm::Value *getVirtualFunctionPointer(CodeGenFunction &CGF, GlobalDecl GD,
+ llvm::Value *This, llvm::Type *Ty);
+
void EmitVirtualDestructorCall(CodeGenFunction &CGF,
const CXXDestructorDecl *Dtor,
CXXDtorType DtorType, SourceLocation CallLoc,
@@ -423,6 +450,34 @@
CGM.EmitGlobal(GlobalDecl(D, Dtor_Base));
}
+llvm::Value *MicrosoftCXXABI::adjustThisArgumentForVirtualCall(
+ CodeGenFunction &CGF, GlobalDecl GD, llvm::Value *This) {
+ GD = GD.getCanonicalDecl();
+ const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
+ if (isa<CXXDestructorDecl>(MD))
+ return This;
+
+ MicrosoftVFTableContext::MethodVFTableLocation ML =
+ CGM.getVFTableContext().getMethodVFTableLocation(GD);
+
+ unsigned AS = cast<llvm::PointerType>(This->getType())->getAddressSpace();
+ llvm::Type *charPtrTy = CGF.Int8Ty->getPointerTo(AS);
+ if (ML.VBase) {
+ This = CGF.Builder.CreateBitCast(This, charPtrTy);
+ llvm::Value *VBaseOffset = CGM.getCXXABI()
+ .GetVirtualBaseClassOffset(CGF, This, MD->getParent(), ML.VBase);
+ This = CGF.Builder.CreateInBoundsGEP(This, VBaseOffset);
+ }
+ CharUnits StaticOffset = ML.VFTableOffset;
+ if (!StaticOffset.isZero()) {
+ assert(StaticOffset.isPositive());
+ This = CGF.Builder.CreateBitCast(This, charPtrTy);
+ This = CGF.Builder
+ .CreateConstInBoundsGEP1_64(This, StaticOffset.getQuantity());
+ }
+ return This;
+}
+
static bool IsDeletingDtor(GlobalDecl GD) {
const CXXMethodDecl* MD = cast<CXXMethodDecl>(GD.getDecl());
if (isa<CXXDestructorDecl>(MD)) {
@@ -457,6 +512,41 @@
}
}
+llvm::Value *MicrosoftCXXABI::adjustThisParameterInVirtualFunctionPrologue(
+ CodeGenFunction &CGF, GlobalDecl GD, llvm::Value *This) {
+ GD = GD.getCanonicalDecl();
+ const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
+ if (isa<CXXDestructorDecl>(MD))
+ return This;
+
+ // In this ABI, every virtual function takes a pointer to one of the
+ // subobjects that first defines it as the 'this' parameter, rather than a
+ // pointer to ther final overrider subobject. Thus, we need to adjust it back
+ // to the final overrider subobject before use.
+ // See comments in the MicrosoftVFTableContext implementation for the details.
+
+ MicrosoftVFTableContext::MethodVFTableLocation ML =
+ CGM.getVFTableContext().getMethodVFTableLocation(GD);
+ CharUnits Adjustment = ML.VFTableOffset;
+ if (ML.VBase) {
+ const ASTRecordLayout &DerivedLayout =
+ CGF.getContext().getASTRecordLayout(MD->getParent());
+ Adjustment += DerivedLayout.getVBaseClassOffset(ML.VBase);
+ }
+
+ if (Adjustment.isZero())
+ return This;
+
+ unsigned AS = cast<llvm::PointerType>(This->getType())->getAddressSpace();
+ llvm::Type *charPtrTy = CGF.Int8Ty->getPointerTo(AS),
+ *thisTy = This->getType();
+
+ This = CGF.Builder.CreateBitCast(This, charPtrTy);
+ assert(Adjustment.isPositive());
+ This = CGF.Builder.CreateConstGEP1_64(This, -Adjustment.getQuantity());
+ return CGF.Builder.CreateBitCast(This, thisTy);
+}
+
void MicrosoftCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) {
EmitThisParam(CGF);
@@ -514,6 +604,24 @@
ImplicitParam, ImplicitParamTy, ArgBeg, ArgEnd);
}
+llvm::Value *MicrosoftCXXABI::getVirtualFunctionPointer(CodeGenFunction &CGF,
+ GlobalDecl GD,
+ llvm::Value *This,
+ llvm::Type *Ty) {
+ GD = GD.getCanonicalDecl();
+ CGBuilderTy &Builder = CGF.Builder;
+
+ Ty = Ty->getPointerTo()->getPointerTo();
+ llvm::Value *VPtr = adjustThisArgumentForVirtualCall(CGF, GD, This);
+ llvm::Value *VTable = CGF.GetVTablePtr(VPtr, Ty);
+
+ MicrosoftVFTableContext::MethodVFTableLocation ML =
+ CGM.getVFTableContext().getMethodVFTableLocation(GD);
+ llvm::Value *VFuncPtr =
+ Builder.CreateConstInBoundsGEP1_64(VTable, ML.Index, "vfn");
+ return Builder.CreateLoad(VFuncPtr);
+}
+
void MicrosoftCXXABI::EmitVirtualDestructorCall(CodeGenFunction &CGF,
const CXXDestructorDecl *Dtor,
CXXDtorType DtorType,
@@ -523,15 +631,15 @@
// We have only one destructor in the vftable but can get both behaviors
// by passing an implicit bool parameter.
- const CGFunctionInfo *FInfo
- = &CGM.getTypes().arrangeCXXDestructor(Dtor, Dtor_Deleting);
+ const CGFunctionInfo *FInfo =
+ &CGM.getTypes().arrangeCXXDestructor(Dtor, Dtor_Deleting);
llvm::Type *Ty = CGF.CGM.getTypes().GetFunctionType(*FInfo);
- llvm::Value *Callee
- = CGF.BuildVirtualCall(GlobalDecl(Dtor, Dtor_Deleting), This, Ty);
+ llvm::Value *Callee =
+ getVirtualFunctionPointer(CGF, GlobalDecl(Dtor, Dtor_Deleting), This, Ty);
ASTContext &Context = CGF.getContext();
- llvm::Value *ImplicitParam
- = llvm::ConstantInt::get(llvm::IntegerType::getInt1Ty(CGF.getLLVMContext()),
+ llvm::Value *ImplicitParam =
+ llvm::ConstantInt::get(llvm::IntegerType::getInt1Ty(CGF.getLLVMContext()),
DtorType == Dtor_Deleting);
CGF.EmitCXXMemberCall(Dtor, CallLoc, Callee, ReturnValueSlot(), This,