From: Argyrios Kyrtzidis <akyrtzi@gmail.com>
Date: Sat, 10 Dec 2011 00:30:38 +0000 (+0000)
Subject: Add a sanity check in SourceManager::getColumnNumber, make sure
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d575254dcd061ad9e6661598f4443d85a7bd1d8b;p=clang

Add a sanity check in SourceManager::getColumnNumber, make sure
we don't try to access beyond the buffer.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@146305 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Basic/SourceManager.cpp b/lib/Basic/SourceManager.cpp
index cdaff2f008..85fe474d66 100644
--- a/lib/Basic/SourceManager.cpp
+++ b/lib/Basic/SourceManager.cpp
@@ -947,13 +947,20 @@ const char *SourceManager::getCharacterData(SourceLocation SL,
 unsigned SourceManager::getColumnNumber(FileID FID, unsigned FilePos,
                                         bool *Invalid) const {
   bool MyInvalid = false;
-  const char *Buf = getBuffer(FID, &MyInvalid)->getBufferStart();
+  const llvm::MemoryBuffer *MemBuf = getBuffer(FID, &MyInvalid);
   if (Invalid)
     *Invalid = MyInvalid;
 
   if (MyInvalid)
     return 1;
 
+  const char *Buf = MemBuf->getBufferStart();
+  if (Buf + FilePos >= MemBuf->getBufferEnd()) {
+    if (Invalid)
+      *Invalid = MyInvalid;
+    return 1;
+  }
+
   unsigned LineStart = FilePos;
   while (LineStart && Buf[LineStart-1] != '\n' && Buf[LineStart-1] != '\r')
     --LineStart;