Initial support for cross-compilation with support for cross compilation to win32

CMakeLists.txt

@@ -1,6 +1,7 @@
 project(GLFW C)
 
 cmake_minimum_required(VERSION 2.4)
+cmake_policy(VERSION 2.4)
 
 set(GLFW_VERSION_MAJOR "3")
 set(GLFW_VERSION_MINOR "0")

toolchains/README.txt

@@ -0,0 +1,10 @@
+This folder contains a collection of toolchains definition in order to 
+support cross compilation. The naming scheme is the following:
+  host-system-compiler.cmake
+
+to use this at the time you run the initial cmake command use the 
+following parameter 
+   -DCMAKE_TOOLCHAIN_FILE=./toolchains/XXX-XXX-XXX.cmake
+ which maps to file in this folder. 
+
+For more details see: http://www.paraview.org/Wiki/CMake_Cross_Compiling 

toolchains/linux-i686-pc-mingw32.cmake

@@ -0,0 +1,13 @@
+# Define the cross compilation environment for cross compiling from linux 
+# to win32
+SET(CMAKE_SYSTEM_NAME    Windows) # Target system name
+SET(CMAKE_SYSTEM_VERSION 1)
+SET(CMAKE_C_COMPILER     "i686-pc-mingw32-gcc")
+SET(CMAKE_CXX_COMPILER   "i686-pc-mingw32-g++")
+SET(CMAKE_RANLIB         "i686-pc-mingw32-ranlib")
+
+#Configure the behaviour of the find commands 
+SET(CMAKE_FIND_ROOT_PATH "/opt/mingw/usr/i686-pc-mingw32")
+SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)

toolchains/linux-mingw32msvc.cmake

@@ -0,0 +1,15 @@
+# Define the cross compilation environment for cross compiling from linux 
+# to win32 it is to be used when debian cross compilation toolchain is 
+# available.
+SET(CMAKE_SYSTEM_NAME    Windows) # Target system name
+SET(CMAKE_SYSTEM_VERSION 1)       # Not really used.
+SET(CMAKE_C_COMPILER     "i586-mingw32msvc-gcc")
+SET(CMAKE_CXX_COMPILER   "i586-mingw32msvc-g++")
+SET(CMAKE_RANLIB         "i586-mingw32msvc-ranlib")
+
+
+#Configure the behaviour of the find commands 
+SET(CMAKE_FIND_ROOT_PATH "/usr/i586-mingw32msvc")
+SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)