[ms-cxxabi] Move CodeGenVTables::needsVTTParameter to ItaniumCXXABI.

This function only makes sense there.  Eventually it should no longer
be part of the CGCXXABI interface, as it is an Itanium-specific detail.

Differential Revision: http://llvm-reviews.chandlerc.com/D821

llvm-svn: 185213

clang/lib/CodeGen/CGCXXABI.cpp

@@ -293,3 +293,7 @@ LValue CGCXXABI::EmitThreadLocalDeclRefExpr(CodeGenFunction &CGF,
   ErrorUnsupportedABI(CGF, "odr-use of thread_local global");
   return LValue();
 }
+
+bool CGCXXABI::NeedsVTTParameter(GlobalDecl GD) {
+  return false;
+}

clang/lib/CodeGen/CGCXXABI.h

@@ -331,6 +331,9 @@ public:
                                QualType ElementType, llvm::Value *&NumElements,
                                llvm::Value *&AllocPtr, CharUnits &CookieSize);
 
+  /// Return whether the given global decl needs a VTT parameter.
+  virtual bool NeedsVTTParameter(GlobalDecl GD);
+
 protected:
   /// Returns the extra size required in order to store the array
   /// cookie for the given type.  Assumes that an array cookie is

clang/lib/CodeGen/CGClass.cpp

@@ -286,7 +286,7 @@ CodeGenFunction::GetAddressOfDerivedClass(llvm::Value *Value,
 llvm::Value *CodeGenFunction::GetVTTParameter(GlobalDecl GD,
                                               bool ForVirtualBase,
                                               bool Delegating) {
-  if (!CodeGenVTables::needsVTTParameter(GD)) {
+  if (!CGM.getCXXABI().NeedsVTTParameter(GD)) {
     // This constructor/destructor does not need a VTT parameter.
     return 0;
   }
@@ -304,7 +304,7 @@ llvm::Value *CodeGenFunction::GetVTTParameter(GlobalDecl GD,
   } else if (RD == Base) {
     // If the record matches the base, this is the complete ctor/dtor
     // variant calling the base variant in a class with virtual bases.
-    assert(!CodeGenVTables::needsVTTParameter(CurGD) &&
+    assert(!CGM.getCXXABI().NeedsVTTParameter(CurGD) &&
            "doing no-op VTT offset in base dtor/ctor?");
     assert(!ForVirtualBase && "Can't have same class as virtual base!");
     SubVTTIndex = 0;
@@ -319,7 +319,7 @@ llvm::Value *CodeGenFunction::GetVTTParameter(GlobalDecl GD,
     assert(SubVTTIndex != 0 && "Sub-VTT index must be greater than zero!");
   }
   
-  if (CodeGenVTables::needsVTTParameter(CurGD)) {
+  if (CGM.getCXXABI().NeedsVTTParameter(CurGD)) {
     // A VTT parameter was passed to the constructor, use it.
     VTT = LoadCXXVTT();
     VTT = Builder.CreateConstInBoundsGEP1_64(VTT, SubVTTIndex);
@@ -1742,7 +1742,7 @@ CodeGenFunction::EmitDelegateCXXConstructorCall(const CXXConstructorDecl *Ctor,
     QualType VoidPP = getContext().getPointerType(getContext().VoidPtrTy);
     DelegateArgs.add(RValue::get(VTT), VoidPP);
 
-    if (CodeGenVTables::needsVTTParameter(CurGD)) {
+    if (CGM.getCXXABI().NeedsVTTParameter(CurGD)) {
       assert(I != E && "cannot skip vtt parameter, already done with args");
       assert((*I)->getType() == VoidPP && "skipping parameter not of vtt type");
       ++I;
@@ -1874,9 +1874,10 @@ CodeGenFunction::InitializeVTablePointer(BaseSubobject Base,
   // Compute the address point.
   llvm::Value *VTableAddressPoint;
 
+  bool NeedsVTTParam = CGM.getCXXABI().NeedsVTTParameter(CurGD);
+
   // Check if we need to use a vtable from the VTT.
-  if (CodeGenVTables::needsVTTParameter(CurGD) &&
-      (RD->getNumVBases() || NearestVBase)) {
+  if (NeedsVTTParam && (RD->getNumVBases() || NearestVBase)) {
     // Get the secondary vpointer index.
     uint64_t VirtualPointerIndex = 
      CGM.getVTables().getSecondaryVirtualPointerIndex(VTableClass, Base);
@@ -1899,7 +1900,7 @@ CodeGenFunction::InitializeVTablePointer(BaseSubobject Base,
   llvm::Value *VirtualOffset = 0;
   CharUnits NonVirtualOffset = CharUnits::Zero();
   
-  if (CodeGenVTables::needsVTTParameter(CurGD) && NearestVBase) {
+  if (NeedsVTTParam && NearestVBase) {
     // We need to use the virtual base offset offset because the virtual base
     // might have a different offset in the most derived class.
     VirtualOffset = CGM.getCXXABI().GetVirtualBaseClassOffset(*this,

clang/lib/CodeGen/CGVTT.cpp

@@ -120,24 +120,6 @@ llvm::GlobalVariable *CodeGenVTables::GetAddrOfVTT(const CXXRecordDecl *RD) {
   return GV;
 }
 
-bool CodeGenVTables::needsVTTParameter(GlobalDecl GD) {
-  const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
-  
-  // We don't have any virtual bases, just return early.
-  if (!MD->getParent()->getNumVBases())
-    return false;
-  
-  // Check if we have a base constructor.
-  if (isa<CXXConstructorDecl>(MD) && GD.getCtorType() == Ctor_Base)
-    return true;
-
-  // Check if we have a base destructor.
-  if (isa<CXXDestructorDecl>(MD) && GD.getDtorType() == Dtor_Base)
-    return true;
-  
-  return false;
-}
-
 uint64_t CodeGenVTables::getSubVTTIndex(const CXXRecordDecl *RD, 
                                         BaseSubobject Base) {
   BaseSubobjectPairTy ClassSubobjectPair(RD, Base);

clang/lib/CodeGen/CGVTables.h

@@ -77,11 +77,6 @@ public:
 
   VTableContext &getVTableContext() { return VTContext; }
 
-  /// needsVTTParameter - Return whether the given global decl needs a VTT
-  /// parameter, which it does if it's a base constructor or destructor with
-  /// virtual bases.
-  static bool needsVTTParameter(GlobalDecl GD);
-
   /// getSubVTTIndex - Return the index of the sub-VTT for the base class of the
   /// given record decl.
   uint64_t getSubVTTIndex(const CXXRecordDecl *RD, BaseSubobject Base);

clang/lib/CodeGen/ItaniumCXXABI.cpp

@@ -162,6 +162,8 @@ public:
       llvm::Function *InitFunc);
   LValue EmitThreadLocalDeclRefExpr(CodeGenFunction &CGF,
                                     const DeclRefExpr *DRE);
+
+  bool NeedsVTTParameter(GlobalDecl GD);
 };
 
 class ARMCXXABI : public ItaniumCXXABI {
@@ -810,7 +812,7 @@ void ItaniumCXXABI::BuildInstanceFunctionParams(CodeGenFunction &CGF,
   assert(MD->isInstance());
 
   // Check if we need a VTT parameter as well.
-  if (CodeGenVTables::needsVTTParameter(CGF.CurGD)) {
+  if (NeedsVTTParameter(CGF.CurGD)) {
     ASTContext &Context = getContext();
 
     // FIXME: avoid the fake decl
@@ -1417,3 +1419,23 @@ LValue ItaniumCXXABI::EmitThreadLocalDeclRefExpr(CodeGenFunction &CGF,
   // FIXME: need setObjCGCLValueClass?
   return LV;
 }
+
+/// Return whether the given global decl needs a VTT parameter, which it does
+/// if it's a base constructor or destructor with virtual bases.
+bool ItaniumCXXABI::NeedsVTTParameter(GlobalDecl GD) {
+  const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
+  
+  // We don't have any virtual bases, just return early.
+  if (!MD->getParent()->getNumVBases())
+    return false;
+  
+  // Check if we have a base constructor.
+  if (isa<CXXConstructorDecl>(MD) && GD.getCtorType() == Ctor_Base)
+    return true;
+
+  // Check if we have a base destructor.
+  if (isa<CXXDestructorDecl>(MD) && GD.getDtorType() == Dtor_Base)
+    return true;
+  
+  return false;
+}

clang/test/CodeGenCXX/microsoft-abi-virtual-inheritance.cpp

@@ -0,0 +1,11 @@
+// RUN: %clang_cc1 %s -fno-rtti -cxx-abi microsoft -triple=i386-pc-win32 -emit-llvm -o %t
+
+struct A {};
+struct B : virtual A {
+  virtual ~B();
+};
+struct C : B {
+  C();
+};
+
+C::C() {}