From 52de271da1d56fe80e924bb57659de96e06246fd Mon Sep 17 00:00:00 2001
From: Chandler Carruth <chandlerc@gmail.com>
Date: Sat, 16 Jun 2012 00:44:07 +0000
Subject: [PATCH] Don't call 'FilesToRemove[0]' when the vector is empty, even
 to compute the address of it. Found by a checking STL implementation used on
 a dragonegg builder. Sorry about this one. =/

llvm-svn: 158582
---
 llvm/lib/Support/Unix/Signals.inc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/lib/Support/Unix/Signals.inc b/llvm/lib/Support/Unix/Signals.inc
index b2e5fd8b0a5f..519511685dd6 100644
--- a/llvm/lib/Support/Unix/Signals.inc
+++ b/llvm/lib/Support/Unix/Signals.inc
@@ -189,7 +189,7 @@ void llvm::sys::SetInterruptFunction(void (*IF)()) {
 bool llvm::sys::RemoveFileOnSignal(const sys::Path &Filename,
                                    std::string* ErrMsg) {
   SignalsMutex.acquire();
-  std::string *OldPtr = &FilesToRemove[0];
+  std::string *OldPtr = FilesToRemove.empty() ? 0 : &FilesToRemove[0];
   FilesToRemove.push_back(Filename.str());
 
   // We want to call 'c_str()' on every std::string in this vector so that if