1 files changed, 3 insertions, 1 deletions
diff --git a/gnu/llvm/tools/clang/lib/Lex/PPCaching.cpp b/gnu/llvm/tools/clang/lib/Lex/PPCaching.cpp
index f5e8cdc25d3..9758557d7b4 100644
--- a/gnu/llvm/tools/clang/lib/Lex/PPCaching.cpp
+++ b/gnu/llvm/tools/clang/lib/Lex/PPCaching.cpp
@@ -105,8 +105,10 @@ void Preprocessor::CachingLex(Token &Result) {
 }
 
 void Preprocessor::EnterCachingLexMode() {
-  if (InCachingLexMode())
+  if (InCachingLexMode()) {
+    assert(CurLexerKind == CLK_CachingLexer && "Unexpected lexer kind");
     return;
+  }
 
   PushIncludeMacroStack();
   CurLexerKind = CLK_CachingLexer;