From 7bf5bc518a4a4c35be84274db5b058e3fb01df3b Mon Sep 17 00:00:00 2001
From: Axel Isouard <axel@isouard.fr>
Date: Fri, 27 Jan 2017 22:35:26 +0100
Subject: [PATCH] Add TARGET_OS and TARGET_CPU variables

---
 CMakeLists.txt                        |  2 ++
 CMakeModules/LibWebRTCSubsystem.cmake | 39 +++++++++++++++++++++++++++
 2 files changed, 41 insertions(+)
 create mode 100644 CMakeModules/LibWebRTCSubsystem.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6c2cfc6..3d8b78b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -24,6 +24,8 @@ option(BUILD_TESTS "Build test binaries" OFF)
 option(BUILD_SAMPLES "Build samples binaries" OFF)
 set(NINJA_ARGS "" CACHE STRING "Ninja arguments to pass before compiling WebRTC")
 
+include(LibWebRTCSubsystem)
+
 #
 # Versioning
 #
diff --git a/CMakeModules/LibWebRTCSubsystem.cmake b/CMakeModules/LibWebRTCSubsystem.cmake
new file mode 100644
index 0000000..929276b
--- /dev/null
+++ b/CMakeModules/LibWebRTCSubsystem.cmake
@@ -0,0 +1,39 @@
+#
+# Subsystem
+#
+
+set(TARGET_OS "" CACHE STRING "Target OS, used as --target_os argument")
+set(TARGET_OS_LIST android chromeos ios linux nacl mac win)
+
+if (TARGET_OS STREQUAL "")
+  if (CMAKE_SYSTEM_NAME MATCHES "Linux")
+    set(TARGET_OS "linux")
+  elseif (CMAKE_SYSTEM_NAME MATCHES "Darwin")
+    set(TARGET_OS "mac")
+  elseif (CMAKE_SYSTEM_NAME MATCHES "Windows")
+    set(TARGET_OS "win")
+  endif ()
+endif (TARGET_OS STREQUAL "")
+
+if (NOT ${TARGET_OS} IN_LIST TARGET_OS_LIST)
+  message(FATAL_ERROR "Unknown value '${TARGET_OS}' for variable TARGET_OS, the following values are supported: ${TARGET_OS_LIST}")
+endif (NOT ${TARGET_OS} IN_LIST TARGET_OS_LIST)
+
+set(TARGET_CPU "" CACHE STRING "Target CPU, used as --target_cpu argument")
+set(TARGET_CPU_LIST x86 x64 arm arm64 mipsel)
+
+if (TARGET_CPU STREQUAL "")
+  if (CMAKE_SYSTEM_PROCESSOR MATCHES "^i.86$")
+    set(TARGET_CPU "x86")
+  elseif (CMAKE_SYSTEM_PROCESSOR MATCHES "^x86.64$")
+    set(TARGET_CPU "x64")
+  elseif (CMAKE_SYSTEM_PROCESSOR STREQUAL "AMD64")
+    set(TARGET_CPU "x64")
+  else ()
+    set(TARGET_CPU ${CMAKE_SYSTEM_PROCESSOR})
+  endif (CMAKE_SYSTEM_PROCESSOR MATCHES "^i.86$")
+endif (TARGET_CPU STREQUAL "")
+
+if (NOT ${TARGET_CPU} IN_LIST TARGET_CPU_LIST)
+  message(FATAL_ERROR "Unknown value '${TARGET_CPU}' for variable TARGET_CPU, the following values are supported: ${TARGET_CPU_LIST}")
+endif (NOT ${TARGET_CPU} IN_LIST TARGET_CPU_LIST)