commit d49b2a7a9d927bb8c314a8c66f7f2e5f3aef4ffd
author Kevin Enderby <enderby@apple.com> Tue Jan 31 23:02:57 2012 +0000
committer Kevin Enderby <enderby@apple.com> Tue Jan 31 23:02:57 2012 +0000
tree 25bf74b081244aad5d0599b2af0eed24f7b16ca9
parent bda59fdd71033a8ddfa30ec4b514753017f3da5c

Fixed a crash in llvm-mc for Mach-O when a symbol difference expression uses a
symbol from an assignment.  In this case the symbol did not have a fragment so
MCObjectWriter::IsSymbolRefDifferenceFullyResolved() should not have been
calling IsSymbolRefDifferenceFullyResolvedImpl() with a NULL fragment and should
just have returned false in that case.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149442 91177308-0d34-0410-b5e6-96231b3b80d8

lib/MC/MCObjectWriter.cpp

diff --git a/lib/MC/MCObjectWriter.cpp b/lib/MC/MCObjectWriter.cpp
index 1888739..030f247 100644
--- a/lib/MC/MCObjectWriter.cpp
+++ b/lib/MC/MCObjectWriter.cpp
@@ -68,6 +68,8 @@
 
   const MCSymbolData &DataA = Asm.getSymbolData(SA);
   const MCSymbolData &DataB = Asm.getSymbolData(SB);
+  if(!DataA.getFragment() || !DataB.getFragment())
+    return false;
 
   return IsSymbolRefDifferenceFullyResolvedImpl(Asm, DataA,
                                                 *DataB.getFragment(),