From a03b9389cab135a99d1b31d4c185030158d11570 Mon Sep 17 00:00:00 2001
From: Greg Clayton <gclayton@apple.com>
Date: Tue, 10 Feb 2015 19:43:15 +0000
Subject: [PATCH] Don't crash when evaluating a DWARF expression has a
 DW_OP_bra with nothing on the value stack.

<rdar://problem/18919125>

llvm-svn: 228729
---
 lldb/source/Expression/DWARFExpression.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lldb/source/Expression/DWARFExpression.cpp b/lldb/source/Expression/DWARFExpression.cpp
index 827bddd8e7bc..e1f29742882a 100644
--- a/lldb/source/Expression/DWARFExpression.cpp
+++ b/lldb/source/Expression/DWARFExpression.cpp
@@ -2198,6 +2198,13 @@ DWARFExpression::Evaluate
         // constant.
         //----------------------------------------------------------------------
         case DW_OP_bra:
+            if (stack.empty())
+            {
+                if (error_ptr)
+                    error_ptr->SetErrorString("Expression stack needs at least 1 item for DW_OP_bra.");
+                return false;
+            }
+            else
             {
                 tmp = stack.back();
                 stack.pop_back();