obs-studio/cmake/common/osconfig.cmake

# OBS CMake operating system bootstrap module

include_guard(GLOBAL)

if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Windows")
  set(CMAKE_C_EXTENSIONS FALSE)
  set(CMAKE_CXX_EXTENSIONS FALSE)
  list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/windows")
  set(OS_WINDOWS TRUE)
elseif(CMAKE_HOST_SYSTEM_NAME STREQUAL "Darwin")
  set(CMAKE_C_EXTENSIONS FALSE)
  set(CMAKE_CXX_EXTENSIONS FALSE)
  list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/macos")
  set(OS_MACOS TRUE)
elseif(CMAKE_HOST_SYSTEM_NAME MATCHES "Linux|FreeBSD|OpenBSD")
  set(CMAKE_CXX_EXTENSIONS FALSE)
  list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/linux")
  string(TOUPPER "${CMAKE_HOST_SYSTEM_NAME}" _SYSTEM_NAME_U)
  set(OS_${_SYSTEM_NAME_U} TRUE)
endif()