cmake_minimum_required(VERSION 3.5)
project(photon C ASM-ATT)

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(CMAKE_EXE_LINKER_FLAGS
    "${CMAKE_EXE_LINKER_FLAGS} -ffreestanding -nostdlib -lgcc")

set(photon_libc_sources "")
set(generic_dirs string)

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

file(GLOB_RECURSE photon_libc_headers ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/include/*.h)

file(GLOB photon_libc_crt
    ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys/${PLATFORM}/machine/${MACHINE}/crt*.s)

add_library(crt OBJECT ${photon_libc_crt})

file(GLOB platform_sources
    ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys/${PLATFORM}/*.c
    ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys/${PLATFORM}/machine/${MACHINE}/*.c
    ${CMAKE_CURRENT_SOURCE_DIR}/photon/libc/sys/${PLATFORM}/machine/${MACHINE}/*.s)

foreach (crt_source ${photon_libc_crt})
    list(REMOVE_ITEM platform_sources ${crt_source})
endforeach (crt_source)

file(GLOB platform_headers
    ${CMAKE_CURRENT_SOURCE_DIR}/photon/sys/${PLATFORM}/*.h
    ${CMAKE_CURRENT_SOURCE_DIR}/photon/sys/${PLATFORM}/machine/${MACHINE}/*.h)

set(photon_libc_sources ${photon_libc_sources} ${platform_sources})
set(photon_libc_headers ${photon_libc_headers} ${platform_headers})

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

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

add_custom_target(sysroot
    DEPENDS ${photon_libc_headers}
    COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/scripts/create-sysroot.sh
        ${CMAKE_CURRENT_SOURCE_DIR}
        ${CMAKE_CURRENT_BINARY_DIR}
        ${PLATFORM} ${MACHINE})

add_dependencies(c sysroot)

add_subdirectory(tests)