Avoid writing a VTABLE_USES record in PCH if there are no entries.

llvm-svn: 110122

1 files changed, 7 insertions, 5 deletions

diff --git a/clang/lib/Frontend/PCHWriter.cpp b/clang/lib/Frontend/PCHWriter.cpp
index 971f5e8fb2c..75592a41c85 100644
--- a/clang/lib/Frontend/PCHWriter.cpp
+++ b/clang/lib/Frontend/PCHWriter.cpp
@@ -2196,11 +2196,13 @@ void PCHWriter::WritePCHCore(Sema &SemaRef, MemorizeStatCalls *StatCalls,
 
   // Build a record containing all of the VTable uses information.
   RecordData VTableUses;
-  VTableUses.push_back(SemaRef.VTableUses.size());
-  for (unsigned I = 0, N = SemaRef.VTableUses.size(); I != N; ++I) {
-    AddDeclRef(SemaRef.VTableUses[I].first, VTableUses);
-    AddSourceLocation(SemaRef.VTableUses[I].second, VTableUses);
-    VTableUses.push_back(SemaRef.VTablesUsed[SemaRef.VTableUses[I].first]);
+  if (!SemaRef.VTableUses.empty()) {
+    VTableUses.push_back(SemaRef.VTableUses.size());
+    for (unsigned I = 0, N = SemaRef.VTableUses.size(); I != N; ++I) {
+      AddDeclRef(SemaRef.VTableUses[I].first, VTableUses);
+      AddSourceLocation(SemaRef.VTableUses[I].second, VTableUses);
+      VTableUses.push_back(SemaRef.VTablesUsed[SemaRef.VTableUses[I].first]);
+    }
   }
 
   // Build a record containing all of dynamic classes declarations.