Abstract out the emission of vtables, add basic support for vtable emission when using -cxx-abi microsoft

Reviewed at http://llvm-reviews.chandlerc.com/D1532

llvm-svn: 191523

1 files changed, 7 insertions, 27 deletions

diff --git a/clang/lib/CodeGen/CGClass.cpp b/clang/lib/CodeGen/CGClass.cpp
index 392fe85f64f..c1226d5681c 100644
--- a/clang/lib/CodeGen/CGClass.cpp
+++ b/clang/lib/CodeGen/CGClass.cpp
@@ -1878,39 +1878,19 @@ CodeGenFunction::InitializeVTablePointer(BaseSubobject Base,
                                          const CXXRecordDecl *NearestVBase,
                                          CharUnits OffsetFromNearestVBase,
                                          const CXXRecordDecl *VTableClass) {
-  const CXXRecordDecl *RD = Base.getBase();
-
   // 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 (NeedsVTTParam && (RD->getNumVBases() || NearestVBase)) {
-    // Get the secondary vpointer index.
-    uint64_t VirtualPointerIndex = 
-     CGM.getVTables().getSecondaryVirtualPointerIndex(VTableClass, Base);
-    
-    /// Load the VTT.
-    llvm::Value *VTT = LoadCXXVTT();
-    if (VirtualPointerIndex)
-      VTT = Builder.CreateConstInBoundsGEP1_64(VTT, VirtualPointerIndex);
-
-    // And load the address point from the VTT.
-    VTableAddressPoint = Builder.CreateLoad(VTT);
-  } else {
-    llvm::Constant *VTable = CGM.getVTables().GetAddrOfVTable(VTableClass);
-    uint64_t AddressPoint =
-      CGM.getVTableContext().getVTableLayout(VTableClass).getAddressPoint(Base);
-    VTableAddressPoint =
-      Builder.CreateConstInBoundsGEP2_64(VTable, 0, AddressPoint);
-  }
+  bool NeedsVirtualOffset;
+  llvm::Value *VTableAddressPoint =
+      CGM.getCXXABI().getVTableAddressPointInStructor(
+          *this, VTableClass, Base, NearestVBase, NeedsVirtualOffset);
+  if (!VTableAddressPoint)
+    return;
 
   // Compute where to store the address point.
   llvm::Value *VirtualOffset = 0;
   CharUnits NonVirtualOffset = CharUnits::Zero();
   
-  if (NeedsVTTParam && NearestVBase) {
+  if (NeedsVirtualOffset) {
     // 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,