[ms-abi] Makes Virtual Base Alignment Look at All Virtual Bases

Prior to this patch, the alignment imposed by virtual bases only 
included direct virtual bases.  This patch fixes it to look at all 
virtual bases.

llvm-svn: 196997

1 files changed, 8 insertions, 5 deletions

diff --git a/clang/lib/AST/RecordLayoutBuilder.cpp b/clang/lib/AST/RecordLayoutBuilder.cpp
index a5b07384dc8..112e6d6981d 100644
--- a/clang/lib/AST/RecordLayoutBuilder.cpp
+++ b/clang/lib/AST/RecordLayoutBuilder.cpp
@@ -2125,8 +2125,6 @@ public:
   /// \brief The alignment of the non-virtual portion of the record layout
   /// Only used for C++ layouts.
   CharUnits NonVirtualAlignment;
-  /// \brief The additional alignment imposed by the virtual bases.
-  CharUnits VirtualAlignment;
   /// \brief The primary base class (if one exists).
   const CXXRecordDecl *PrimaryBase;
   /// \brief The class we share our vb-pointer with.
@@ -2265,7 +2263,6 @@ MicrosoftRecordLayoutBuilder::initializeCXXLayout(const CXXRecordDecl *RD) {
   HasExtendableVFPtr = false;
   SharedVBPtrBase = 0;
   PrimaryBase = 0;
-  VirtualAlignment = CharUnits::One();
   LeadsWithZeroSizedBase = false;
 
   // If the record has a dynamic base class, attempt to choose a primary base
@@ -2285,7 +2282,6 @@ MicrosoftRecordLayoutBuilder::initializeCXXLayout(const CXXRecordDecl *RD) {
       HasZeroSizedSubObject = true;
     // Handle virtual bases.
     if (i->isVirtual()) {
-      VirtualAlignment = std::max(VirtualAlignment, getBaseAlignment(Layout));
       HasVBPtr = true;
       continue;
     }
@@ -2555,7 +2551,14 @@ void MicrosoftRecordLayoutBuilder::layoutVirtualBases(const CXXRecordDecl *RD) {
   if (!HasVBPtr)
     return;
 
-  updateAlignment(VirtualAlignment);
+  for (CXXRecordDecl::base_class_const_iterator i = RD->vbases_begin(),
+                                                e = RD->vbases_end();
+       i != e; ++i) {
+    const CXXRecordDecl *BaseDecl =
+        cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
+    const ASTRecordLayout &Layout = Context.getASTRecordLayout(BaseDecl);
+    updateAlignment(getBaseAlignment(Layout));
+  }
   PreviousBaseLayout = 0;
 
   // Zero-sized v-bases obey the alignment attribute so apply it here.  The