From 95fc2e46526e0b83122613f3125dc10f8c254e89 Mon Sep 17 00:00:00 2001
From: Pere Mato <pere.mato@cern.ch>
Date: Wed, 13 Aug 2014 14:06:38 +0200
Subject: [PATCH] Correct the problem with -pthread flag when building with
 CMake. Should fix issue ROOT-6390

---
 cmake/modules/CheckCompiler.cmake     | 8 ++++++++
 cmake/modules/RootBuildOptions.cmake  | 1 +
 cmake/modules/RootConfiguration.cmake | 4 ++--
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/cmake/modules/CheckCompiler.cmake b/cmake/modules/CheckCompiler.cmake
index e25d601..c0f22bd 100644
--- a/cmake/modules/CheckCompiler.cmake
+++ b/cmake/modules/CheckCompiler.cmake
@@ -75,6 +75,11 @@ endif()
 
 #---Need to locate thead libraries and options to set properly some compilation flags---------------- 
 find_package(Threads)
+if(CMAKE_USE_PTHREADS_INIT)
+  set(CMAKE_THREAD_FLAG -pthread)
+else()
+  set(CMAKE_THREAD_FLAG)
+endif()
 
 #---Setup details depending opn the major platform type----------------------------------------------
 if(CMAKE_SYSTEM_NAME MATCHES Linux)
@@ -85,6 +90,9 @@ elseif(WIN32)
   include(SetupWindows)
 endif()
 
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${CMAKE_THREAD_FLAG}")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${CMAKE_THREAD_FLAG}")
+
 if(cxx11)
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
   if(CMAKE_COMPILER_IS_GNUCXX)
diff --git a/cmake/modules/RootBuildOptions.cmake b/cmake/modules/RootBuildOptions.cmake
index e2db2b4..76af457 100644
--- a/cmake/modules/RootBuildOptions.cmake
+++ b/cmake/modules/RootBuildOptions.cmake
@@ -170,6 +170,7 @@ ROOT_BUILD_OPTION(srp ON "SRP support, requires SRP source tree")
 ROOT_BUILD_OPTION(ssl ON "SSL encryption support, requires openssl")
 ROOT_BUILD_OPTION(gnuinstall OFF "Perform installation following the GNU guidelines")
 ROOT_BUILD_OPTION(table ${table_defvalue} "Build libTable contrib library")
+ROOT_BUILD_OPTION(thread ON "Using thread library (cannot be disabled)")
 ROOT_BUILD_OPTION(tmva ON "Build TMVA multi variate analysis library")
 ROOT_BUILD_OPTION(unuran ${unuran_defvalue} "UNURAN - package for generating non-uniform random numbers")
 ROOT_BUILD_OPTION(vc ${vc_defvalue} "Vc adds a few new types for portable and intuitive SIMD programming")
diff --git a/cmake/modules/RootConfiguration.cmake b/cmake/modules/RootConfiguration.cmake
index 955ebde..b63c543 100644
--- a/cmake/modules/RootConfiguration.cmake
+++ b/cmake/modules/RootConfiguration.cmake
@@ -72,8 +72,8 @@ set(xpmlibdir -L${X11_LIBRARY_DIR})
 set(xpmlib ${X11_Xpm_LIB})
 set(enable_xft ${value${xft}})
 
-set(enable_thread yes)
-set(threadflag)
+set(enable_thread ${value${thread}})
+set(threadflag ${CMAKE_THREAD_FLAG})
 set(threadlibdir)
 set(threadlib ${CMAKE_THREAD_LIBS_INIT})
 
-- 
1.8.2