env do |env|
  env["CFLAGS"] << "-Wall"
  env.Program("program", glob("src/**/*.c"))
end

env do |env|
  env["DFLAGS"] << "-Wall"
  env.Program("program", glob("src/**/*.d"))
end

main_env = env do |env|
  env["CFLAGS"] = ["-fshort-enums", "-O3"]
  env["CPPDEFINES"] << "SOME_DEFINE"
  env["LIBS"] = ["SDL"]
  env.Program("program", glob("src/**/*.cc"))
end

test_env = main_env.clone do |env|
  env["CFLAGS"] -= ["-O3"]
  env["CFLAGS"] += ["-g", "-O0"]
  env["CPPDEFINES"] = "ENABLE_TESTS"
  env.Program("program-test", glob("src/**/*.cc"))
end

class GenerateFoo < Builder
  def run(options)
    target, cache = options.values_at(:target, :cache)
    cache.mkdir_p(File.dirname(target))
    File.open(target, "w") do |fh|
      fh.puts <<EOF
#define GENERATED 42
EOF
    end
    target
  end
end

env do |env|
  env.add_builder(GenerateFoo)
  env.GenerateFoo("foo.h", [])
  env.Program("a.out", glob("*.c"))
end

env do |env|
  env["CFLAGS"] = ["-O3", "-Wall"]
  env.add_build_hook do |builder|
    if builder.sources.first =~ %r{src/third-party/}
      build_op[:vars]["CFLAGS"] -= ["-Wall"]
    end
  end
  env.Program("program", glob("**/*.cc"))
end

env do |env|
  env.Library("mylib.a", glob("src/**/*.c"))
end

env do |env|
  env.Yacc("^/parser.tab.cc", "parser.yy")
end

binutils_version = "2.35"
binutils_checksum = "1b11659fb49e20e18db460d44485f09442c8c56d5df165de9461eb09c8302f85"
gcc_version = "10.2.0"
gcc_checksum = "b8dd4368bb9c7f0b98188317ee0254dd8cc99d1e3a18d0ff146c855fe16c1d8c"
install_path = File.expand_path("i686-elf-gcc")
target = "i686-elf"
path_prepend "#{install_path}/bin"

configure do
  check_c_compiler "gcc"
  check_program "make"
  check_program "bison"
  check_program "flex"
  check_program "texi2any", on_fail: "Install the texinfo package"
  check_program "wget"
  check_lib "gmp", on_fail: "Install the libgmp-dev package"
  check_lib "mpc", on_fail: "Install the libmpc-dev package"
  check_lib "mpfr", on_fail: "Install the libmpfr-dev package"
end

default do
  unless Dir.exist?(install_path)

    # Download archives.
    download "https://ftp.gnu.org/gnu/binutils/binutils-#{binutils_version}.tar.xz",
      "#{build_dir}/binutils-#{binutils_version}.tar.xz",
      sha256sum: binutils_checksum

    download "https://ftp.gnu.org/gnu/gcc/gcc-#{gcc_version}/gcc-#{gcc_version}.tar.xz",
      "#{build_dir}/gcc-#{gcc_version}.tar.xz",
      sha256sum: gcc_checksum

    # Extract archives.
    sh "tar", "xJf", "binutils-#{binutils_version}.tar.xz",
      chdir: build_dir

    sh "tar", "xJf", "gcc-#{gcc_version}.tar.xz",
      chdir: build_dir

    # Build binutils.
    rm_rf "#{build_dir}/build-binutils"
    mkdir_p "#{build_dir}/build-binutils"
    cd "#{build_dir}/build-binutils" do
      sh %W[../binutils-#{binutils_version}/configure
        --target=#{target} --prefix=#{install_path} --with-sysroot --disable-nls
        --disable-werror]
      sh "make"
      sh "make install"
    end

    # Build gcc.
    rm_rf "#{build_dir}/build-gcc"
    mkdir_p "#{build_dir}/build-gcc"
    cd "#{build_dir}/build-gcc" do
      sh %W[../gcc-#{gcc_version}/configure
        --target=#{target} --prefix=#{install_path} --disable-nls
        --enable-languages=c,c++ --without-headers]
      sh "make all-gcc"
      sh "make all-target-libgcc"
      sh "make install-gcc"
      sh "make install-target-libgcc"
    end
  end
end

clean do
  rm_f "#{build_dir}/binutils-#{binutils_version}.tar.xz"
  rm_rf "#{build_dir}/binutils-#{binutils_version}"
  rm_rf "#{build_dir}/build-binutils"
  rm_f "#{build_dir}/gcc-#{gcc_version}.tar.xz"
  rm_rf "#{build_dir}/gcc-#{gcc_version}"
  rm_rf "#{build_dir}/build-gcc"
end

distclean do
  rm_rf install_path
end