Added conditional guard 'if (CurLexer)' when using SetCommentRetentionState().
This is because the PTHLexer will not support this method. Performance testing
on preprocessing Cocoa.h shows that this results in a negligible performance
difference (less than 1%).

I tried making Lexer::SetCommentRetentionState() an out-of-line function (a
precursor to making it a virtual function in PreprocessorLexer) and noticed a 1%
decrease in speed (it is called in a hot part of the Preprocessor).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@59477 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed