From 6b0c5ad0965ef13e14ee79aaeedec24a5d3ee3e1 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Sun, 12 Oct 2008 01:23:27 +0000
Subject: [PATCH] add a comment.

llvm-svn: 57394
---
 clang/lib/Lex/Lexer.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/clang/lib/Lex/Lexer.cpp b/clang/lib/Lex/Lexer.cpp
index e930f3def2e0..63bf58a12c8f 100644
--- a/clang/lib/Lex/Lexer.cpp
+++ b/clang/lib/Lex/Lexer.cpp
@@ -113,6 +113,8 @@ Lexer::Lexer(SourceLocation fileloc, const LangOptions &features,
   Is_PragmaLexer = false;
   InitCharacterInfo();
   
+  // If a MemoryBuffer was specified, use its start as BufferStart. This affects
+  // the source location objects produced by this lexer.
   BufferStart = FromFile ? FromFile->getBufferStart() : BufStart;
   BufferPtr = BufStart;
   BufferEnd = BufEnd;