2 files changed, 18 insertions, 1 deletions
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 049eebd82b6..e88ea946e72 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -1866,6 +1866,16 @@ CharUnits ASTContext::getAlignOfGlobalVarInChars(QualType T) const {
   return toCharUnitsFromBits(getAlignOfGlobalVar(T));
 }
 
+CharUnits ASTContext::getOffsetOfBaseWithVBPtr(const CXXRecordDecl *RD) const {
+  CharUnits Offset = CharUnits::Zero();
+  const ASTRecordLayout *Layout = &getASTRecordLayout(RD);
+  while (const CXXRecordDecl *Base = Layout->getBaseSharingVBPtr()) {
+    Offset += Layout->getBaseClassOffset(Base);
+    Layout = &getASTRecordLayout(Base);
+  }
+  return Offset;
+}
+
 /// DeepCollectObjCIvars -
 /// This routine first collects all declared, but not synthesized, ivars in
 /// super class and then collects all ivars, including those synthesized for
diff --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
index 26894bb91eb..c50db60abe5 100644
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -502,6 +502,9 @@ void MicrosoftCXXNameMangler::mangleMemberDataPointer(const CXXRecordDecl *RD,
     FieldOffset /= getASTContext().getCharWidth();
 
     VBTableOffset = 0;
+
+    if (IM == MSInheritanceAttr::Keyword_virtual_inheritance)
+      FieldOffset -= getASTContext().getOffsetOfBaseWithVBPtr(RD).getQuantity();
   } else {
     FieldOffset = RD->nullFieldOffsetIsZero() ? 0 : -1;
 
@@ -570,6 +573,10 @@ MicrosoftCXXNameMangler::mangleMemberFunctionPointer(const CXXRecordDecl *RD,
       mangleName(MD);
       mangleFunctionEncoding(MD, /*ShouldMangle=*/true);
     }
+
+    if (VBTableOffset == 0 &&
+        IM == MSInheritanceAttr::Keyword_virtual_inheritance)
+      NVOffset -= getASTContext().getOffsetOfBaseWithVBPtr(RD).getQuantity();
   } else {
     // Null single inheritance member functions are encoded as a simple nullptr.
     if (IM == MSInheritanceAttr::Keyword_single_inheritance) {
@@ -582,7 +589,7 @@ MicrosoftCXXNameMangler::mangleMemberFunctionPointer(const CXXRecordDecl *RD,
   }
 
   if (MSInheritanceAttr::hasNVOffsetField(/*IsMemberFunction=*/true, IM))
-    mangleNumber(NVOffset);
+    mangleNumber(static_cast<uint32_t>(NVOffset));
   if (MSInheritanceAttr::hasVBPtrOffsetField(IM))
     mangleNumber(VBPtrOffset);
   if (MSInheritanceAttr::hasVBTableOffsetField(IM))