2 files changed, 7 insertions, 4 deletions
diff --git a/lib/Lex/Lexer.cpp b/lib/Lex/Lexer.cpp
index 429780eaea..91c4f66403 100644
--- a/lib/Lex/Lexer.cpp
+++ b/lib/Lex/Lexer.cpp
@@ -2698,8 +2698,6 @@ bool Lexer::isCodeCompletionPoint(const char *CurPtr) const {
 
 uint32_t Lexer::tryReadUCN(const char *&StartPtr, const char *SlashLoc,
                            Token *Result) {
-  assert(LangOpts.CPlusPlus || LangOpts.C99);
-
   unsigned CharSize;
   char Kind = getCharAndSize(StartPtr, CharSize);
 
@@ -2711,6 +2709,11 @@ uint32_t Lexer::tryReadUCN(const char *&StartPtr, const char *SlashLoc,
   else
     return 0;
 
+  if (!LangOpts.CPlusPlus && !LangOpts.C99) {
+    Diag(SlashLoc, diag::warn_ucn_not_valid_in_c89);
+    return 0;
+  }
+
   const char *CurPtr = StartPtr + CharSize;
   const char *KindLoc = &CurPtr[-1];
 
@@ -2737,7 +2740,7 @@ uint32_t Lexer::tryReadUCN(const char *&StartPtr, const char *SlashLoc,
           }
         }
       }
-      
+
       return 0;
     }
 
diff --git a/lib/Lex/LiteralSupport.cpp b/lib/Lex/LiteralSupport.cpp
index 1647aa5381..09a94a1143 100644
--- a/lib/Lex/LiteralSupport.cpp
+++ b/lib/Lex/LiteralSupport.cpp
@@ -277,7 +277,7 @@ static bool ProcessUCNEscape(const char *ThisTokBegin, const char *&ThisTokBuf,
 
   if (!Features.CPlusPlus && !Features.C99 && Diags)
     Diag(Diags, Features, Loc, ThisTokBegin, UcnBegin, ThisTokBuf,
-         diag::warn_ucn_not_valid_in_c89);
+         diag::warn_ucn_not_valid_in_c89_literal);
 
   return true;
 }