While calculating original type size for a derived type, handle type variants encoded as DIDerivedType appropriately.
This improves bitfield support.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86073 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/DebugInfo.cpp b/lib/Analysis/DebugInfo.cpp
index 7bff11e..b64dbf4 100644
--- a/lib/Analysis/DebugInfo.cpp
+++ b/lib/Analysis/DebugInfo.cpp
@@ -401,12 +401,18 @@
 /// getOriginalTypeSize - If this type is derived from a base type then
 /// return base type size.
 uint64_t DIDerivedType::getOriginalTypeSize() const {
-  DIType BT = getTypeDerivedFrom();
-  if (!BT.isNull() && BT.isDerivedType())
-    return DIDerivedType(BT.getNode()).getOriginalTypeSize();
-  if (BT.isNull())
-    return getSizeInBits();
-  return BT.getSizeInBits();
+  unsigned Tag = getTag();
+  if (Tag == dwarf::DW_TAG_member || Tag == dwarf::DW_TAG_typedef ||
+      Tag == dwarf::DW_TAG_const_type || Tag == dwarf::DW_TAG_volatile_type ||
+      Tag == dwarf::DW_TAG_restrict_type) {
+    DIType BaseType = getTypeDerivedFrom();
+    if (BaseType.isDerivedType())
+      return DIDerivedType(BaseType.getNode()).getOriginalTypeSize();
+    else
+      return BaseType.getSizeInBits();
+  }
+    
+  return getSizeInBits();
 }
 
 /// describes - Return true if this subprogram provides debugging