Add Peek

Add a peek function to let the Lexer look at a character arbitrarily
far ahead in the stream without consuming anything.  We need this to
disambiguate numbers and operands of a paste operation.  For example:

def foo#8i

Without lookahead the lexer will treat '8' as a number rather than as
part of a string to be pasted to form an identifier.

llvm-svn: 142512

1 files changed, 1 insertions, 0 deletions

diff --git a/llvm/lib/TableGen/TGLexer.h b/llvm/lib/TableGen/TGLexer.h
index 84d328b12d9..24f8ea4ce5a 100644
--- a/llvm/lib/TableGen/TGLexer.h
+++ b/llvm/lib/TableGen/TGLexer.h
@@ -109,6 +109,7 @@ private:
   tgtok::TokKind ReturnError(const char *Loc, const Twine &Msg);
   
   int getNextChar();
+  int peekNextChar(int Index);
   void SkipBCPLComment();
   bool SkipCComment();
   tgtok::TokKind LexIdentifier();