Optimize the preprocessor's handling of the __import_module__

keyword. We now handle this keyword in HandleIdentifier, making a note
for ourselves when we've seen the __import_module__ keyword so that
the next lexed token can trigger a module import (if needed). This
greatly simplifies Preprocessor::Lex(), and completely erases the 5.5%
-Eonly slowdown Argiris noted when I originally implemented
__import_module__. Big thanks to Argiris for noting that horrible
regression!



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@139265 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 0 deletions

diff --git a/lib/Lex/PPCaching.cpp b/lib/Lex/PPCaching.cpp
index 33106591c3..986341b986 100644
--- a/lib/Lex/PPCaching.cpp
+++ b/lib/Lex/PPCaching.cpp
@@ -74,6 +74,8 @@ void Preprocessor::EnterCachingLexMode() {
     return;
 
   PushIncludeMacroStack();
+  if (CurLexerKind != CLK_LexAfterModuleImport)
+    CurLexerKind = CLK_CachingLexer;
 }