include_guard(GLOBAL)

macro(find_compiler_file NAME OUTPUT_VARIABLE)
  execute_process(COMMAND
    "${CMAKE_CXX_COMPILER}"
    "-mno-red-zone"
    "-print-file-name=${NAME}"
    OUTPUT_STRIP_TRAILING_WHITESPACE
    OUTPUT_VARIABLE "${OUTPUT_VARIABLE}"
    ERROR_QUIET
  )
  mark_as_advanced("${OUTPUT_VARIABLE}")
endmacro()

set(PLATFORM_TARGET "x86_64-pc-elf")

set(CMAKE_TRY_COMPILE_TARGET_TYPE "STATIC_LIBRARY")

set(CMAKE_SYSTEM_NAME "Generic-ELF")
set(CMAKE_SYSTEM_PROCESSOR "x86_64")

set(CMAKE_ASM_COMPILER_TARGET "${PLATFORM_TARGET}")
set(CMAKE_CXX_COMPILER_TARGET "${PLATFORM_TARGET}")

find_program(CMAKE_ASM_COMPILER "${CMAKE_ASM_COMPILER_TARGET}-gcc" REQUIRED)
find_program(CMAKE_CXX_COMPILER "${CMAKE_CXX_COMPILER_TARGET}-g++" REQUIRED)

set(CMAKE_CXX_FLAGS_INIT
"-mno-red-zone \
-mcmodel=large \
-fno-rtti \
-fno-exceptions \
-ffunction-sections \
-fdata-sections"
)

set(CMAKE_CXX_FLAGS_DEBUG "-ggdb3")
set(CMAKE_ASM_FLAGS_DEBUG "-ggdb3")

set(CMAKE_ASM_FLAGS_MINSIZEREL "-Os -DNDEBUG -ggdb3")
set(CMAKE_CXX_FLAGS_MINSIZEREL "-Os -DNDEBUG -ggdb3")

set(CMAKE_ASM_FLAGS_RELEASE "-O3 -DNDEBUG -ggdb3")
set(CMAKE_CXX_FLAGS_RELEASE "-O3 -DNDEBUG -ggdb3")

set(CMAKE_ASM_FLAGS_RELWITHDEBINFO "-O2 -DNDEBUG -ggdb3")
set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-O2 -DNDEBUG -ggdb3")

set(CMAKE_EXE_LINKER_FLAGS_INIT "-nostartfiles -Wl,--gc-sections")

find_compiler_file("crtbegin.o" CRT_BEGIN_PATH)
find_compiler_file("crtend.o" CRT_END_PATH)

set(CMAKE_CXX_LINK_EXECUTABLE
"<CMAKE_CXX_COMPILER> \
<FLAGS> \
<CMAKE_CXX_LINK_FLAGS> \
<LINK_FLAGS> \
${CRT_BEGIN_PATH} \
<OBJECTS> \
-o <TARGET> \
<LINK_LIBRARIES> \
-lgcc \
${CRT_END_PATH}"
)