cmake: Add proper detection of sys/mman.h. Fixes #450

Signed-off-by: Jerry Jacobs <jerry.jacobs@dualinventive.com>

CMakeLists.txt

@@ -2,6 +2,7 @@ project(stlink C)
 cmake_minimum_required(VERSION 2.8.7)
 
 include(CheckCCompilerFlag)
+include(CheckIncludeFile)
 find_package(PkgConfig)
 
 set(CMAKE_MODULE_PATH "${CMAKE_MODULE_PATH};${CMAKE_SOURCE_DIR}/cmake/modules")
@@ -47,6 +48,11 @@ elseif()
 	add_cflag_if_supported("-O2")
 endif()
 
+CHECK_INCLUDE_FILE(sys/mman.h STLINK_HAVE_SYS_MMAN_H)
+if (STLINK_HAVE_SYS_MMAN_H)
+	add_definitions(-DSTLINK_HAVE_SYS_MMAN_H)
+endif()
+
 set(STLINK_HEADERS
 	include/stlink.h
 	include/stlink/usb.h

include/stlink/mmap.h

@@ -1,7 +1,7 @@
 #ifndef STLINK_MMAP_H
 #define STLINK_MMAP_H
 
-#ifdef HAVE_SYS_MMAN_H
+#ifdef STLINK_HAVE_SYS_MMAN_H
 #include <sys/mman.h>
 #else