Add back warning about a PTH file not containing any identifiers, but don't make
it a hard error.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@67424 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PTHLexer.cpp b/lib/Lex/PTHLexer.cpp
index b5f5afd..e547ce5 100644
--- a/lib/Lex/PTHLexer.cpp
+++ b/lib/Lex/PTHLexer.cpp
@@ -675,6 +675,12 @@
 
   llvm::OwningPtr<PTHStringIdLookup> SL(PTHStringIdLookup::Create(StringIdTable,
                                                                   BufBeg));
+  
+  // Issue a warning about the PTH file containing no identifiers.                                                                
+  if (!FL->isEmpty() && SL->isEmpty()) {
+    InvalidPTH(Diags, "PTH file contains no identifiers.");
+  }
+
   // Get the location of the spelling cache.
   const unsigned char* spellingBaseOffset = PrologueOffset + sizeof(uint32_t)*3;
   const unsigned char* spellingBase = BufBeg + ReadLE32(spellingBaseOffset);