cmake_minimum_required(VERSION 3.5)
project(photon)

macro(subdirlist result curdir)
    file(GLOB children RELATIVE ${curdir} ${curdir}/*)
    set(dirlist "")
    foreach (child ${children})
        if (IS_DIRECTORY ${curdir}/${child})
            list(APPEND dirlist ${child})
        endif()
    endforeach()
    set(${result} ${dirlist})
endmacro()

subdirlist(machine_dirs ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/machine)

if (NOT PLATFORM)
    set(PLATFORM "linux")
endif ()

if (NOT MACHINE)
    set(supported_machines "")
    foreach (dir ${machine_dirs})
        set(supported_machines "${supported_machines}${dir} ")
    endforeach (dir)

    message(FATAL_ERROR "No machine architecture specified.\n"
        " Supported machines: ${supported_machines}\n"
        " Ex. `cmake -DMACHINE=x86_64 <dir>`")
endif ()

if (NOT EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys/${PLATFORM})
    message(FATAL_ERROR "Unsupported platform: ${PLATFORM}")
endif ()


message(STATUS "Target platform: ${PLATFORM}")

set(photon_libc_sources "")
set(generic_dirs string include)

foreach (dir ${generic_dirs})
    file(GLOB_RECURSE dir_sources ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/${dir}/*.c)
    set(photon_libc_sources ${photon_libc_sources} ${dir_sources})
endforeach (dir)

file(GLOB_RECURSE platform_sources ${CMAKE_CURRENT_SOURCE_DIR}/photon/sys/${PLATFORM})
set(photon_libc_sources ${photon_libc_sources} ${platform_sources})

add_library(c STATIC ${photon_libc_sources})
target_compile_options(c PRIVATE -ffreestanding -nostdlib -nostdinc)

target_include_directories(c PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/include)