In MeasureTokenLength, the FileLoc supplied to the lexer must point to the start of the buffer, or we risk overflow.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@115117 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 1 deletions

diff --git a/lib/Lex/Lexer.cpp b/lib/Lex/Lexer.cpp
index 917829be47..519dd82285 100644
--- a/lib/Lex/Lexer.cpp
+++ b/lib/Lex/Lexer.cpp
@@ -242,7 +242,8 @@ unsigned Lexer::MeasureTokenLength(SourceLocation Loc,
     return 0;
 
   // Create a lexer starting at the beginning of this token.
-  Lexer TheLexer(Loc, LangOpts, Buffer.begin(), StrData, Buffer.end());
+  Lexer TheLexer(SM.getLocForStartOfFile(LocInfo.first), LangOpts,
+                 Buffer.begin(), StrData, Buffer.end());
   TheLexer.SetCommentRetentionState(true);
   Token TheTok;
   TheLexer.LexFromRawLexer(TheTok);