From 61ad7ec0f78c5089ddc7c1ceda22d674387e1803 Mon Sep 17 00:00:00 2001
From: Devang Patel <dpatel@apple.com>
Date: Thu, 20 Dec 2007 00:24:01 +0000
Subject: [PATCH] Add lto version check mechanism.

llvm-svn: 45238
---
 include/llvm/LinkTimeOptimizer.h | 4 +++-
 tools/lto/lto.cpp                | 5 ++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/include/llvm/LinkTimeOptimizer.h b/include/llvm/LinkTimeOptimizer.h
index 164232d2098..fe87ae0acb7 100644
--- a/include/llvm/LinkTimeOptimizer.h
+++ b/include/llvm/LinkTimeOptimizer.h
@@ -20,6 +20,8 @@
 #include <set>
 #include <llvm/ADT/hash_map>
 
+#define LLVM_LTO_VERSION 1
+
 namespace llvm {
 
   class Module;
@@ -148,6 +150,6 @@ namespace llvm {
 /// linker to use dlopen() interface to dynamically load LinkTimeOptimizer.
 /// extern "C" helps, because dlopen() interface uses name to find the symbol.
 extern "C"
-llvm::LinkTimeOptimizer *createLLVMOptimizer();
+llvm::LinkTimeOptimizer *createLLVMOptimizer(unsigned VERSION = LLVM_LTO_VERSION);
 
 #endif
diff --git a/tools/lto/lto.cpp b/tools/lto/lto.cpp
index e7e00e7f62c..bc752340d50 100644
--- a/tools/lto/lto.cpp
+++ b/tools/lto/lto.cpp
@@ -45,8 +45,11 @@
 using namespace llvm;
 
 extern "C"
-llvm::LinkTimeOptimizer *createLLVMOptimizer()
+llvm::LinkTimeOptimizer *createLLVMOptimizer(unsigned VERSION)
 {
+  if (VERSION != LLVM_LTO_VERSION)
+    return NULL;
+
   llvm::LTO *l = new llvm::LTO();
   return l;
 }