allow the HandlerComment callback to push tokens into the
preprocessor.  This could be used by an OpenMP implementation
or something.  Patch by Abramo Bagnara!


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@93795 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/Preprocessor.cpp b/lib/Lex/Preprocessor.cpp
index 26bb3a9..586202b 100644
--- a/lib/Lex/Preprocessor.cpp
+++ b/lib/Lex/Preprocessor.cpp
@@ -583,11 +583,18 @@
   CommentHandlers.erase(Pos);
 }
 
-void Preprocessor::HandleComment(SourceRange Comment) {
+bool Preprocessor::HandleComment(Token &result, SourceRange Comment) {
+  bool AnyPendingTokens = false;
   for (std::vector<CommentHandler *>::iterator H = CommentHandlers.begin(),
        HEnd = CommentHandlers.end();
-       H != HEnd; ++H)
-    (*H)->HandleComment(*this, Comment);
+       H != HEnd; ++H) {
+    if ((*H)->HandleComment(*this, Comment))
+      AnyPendingTokens = true;
+  }
+  if (!AnyPendingTokens || getCommentRetentionState())
+    return false;
+  Lex(result);
+  return true;
 }
 
 CommentHandler::~CommentHandler() { }