PTHManager::Create() now creates a PTHManager even if the PTH file contains no
cached tokens. This is for use with -include-pth.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@67385 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PTHLexer.cpp b/lib/Lex/PTHLexer.cpp
index 0a810ce..e62accb 100644
--- a/lib/Lex/PTHLexer.cpp
+++ b/lib/Lex/PTHLexer.cpp
@@ -648,10 +648,11 @@
   }
   
   llvm::OwningPtr<PTHFileLookup> FL(PTHFileLookup::Create(FileTable, BufBeg));
-  if (FL->isEmpty()) {
+  
+  // Warn if the PTH file is empty.  We still want to create a PTHManager
+  // as the PTH could be used with -include-pth.
+  if (FL->isEmpty())
     InvalidPTH(Diags, "PTH file contains no cached source data");
-    return 0;
-  }
   
   // Get the location of the table mapping from persistent ids to the
   // data needed to reconstruct identifiers.
@@ -674,7 +675,7 @@
 
   llvm::OwningPtr<PTHStringIdLookup> SL(PTHStringIdLookup::Create(StringIdTable,
                                                                   BufBeg));
-  if (SL->isEmpty()) {
+  if (!FL->isEmpty() && SL->isEmpty()) {
     InvalidPTH(Diags, "PTH file contains no identifiers.");
     return 0;
   }