From dd16a012a4f1423eafb8be05b3302960a36b7cab Mon Sep 17 00:00:00 2001
From: proller <proller@github.com>
Date: Fri, 25 Jan 2019 22:18:05 +0300
Subject: [PATCH] IPO fixes

---
 CMakeLists.txt | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8b1903a43d3..f7297f31ed8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,19 +1,19 @@
 project (ClickHouse)
-cmake_minimum_required (VERSION 3.9)
+cmake_minimum_required (VERSION 3.3)
 
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules/")
 
-set(ENABLE_IPO OFF CACHE STRING "Enable inter-procedural optimization (aka LTO)")
-
-if (ENABLE_IPO)
-include(CheckIPOSupported)
-check_ipo_supported(RESULT IPO_SUPPORTED OUTPUT IPO_NOT_SUPPORTED)
-if(IPO_SUPPORTED)
-    message(STATUS "IPO/LTO is supported, enabling")
-    set(CMAKE_INTERPROCEDURAL_OPTIMIZATION TRUE)
-else()
-    message(STATUS "IPO/LTO is not supported: <${IPO_NOT_SUPPORTED}>")
-endif()
+option(ENABLE_IPO "Enable inter-procedural optimization (aka LTO)" OFF) # need cmake 3.9+
+if(ENABLE_IPO)
+    cmake_policy(SET CMP0069 NEW)
+    include(CheckIPOSupported)
+    check_ipo_supported(RESULT IPO_SUPPORTED OUTPUT IPO_NOT_SUPPORTED)
+    if(IPO_SUPPORTED)
+        message(STATUS "IPO/LTO is supported, enabling")
+        set(CMAKE_INTERPROCEDURAL_OPTIMIZATION TRUE)
+    else()
+        message(STATUS "IPO/LTO is not supported: <${IPO_NOT_SUPPORTED}>")
+    endif()
 else()
     message(STATUS "IPO/LTO not enabled.")
 endif()