# Copyright 2019 The Fuchsia Authors
#
# Use of this source code is governed by a MIT-style
# license that can be found in the LICENSE file or at
# https://opensource.org/licenses/MIT

declare_args() {
  # Version string embedded in the kernel for `zx_system_get_version_string`.
  # If set to the default "", a string is generated based on the fuchsia.git
  # revision of the checkout.
  kernel_version_string = ""
}

# The version string depends solely on the source and doesn't vary across
# machines or toolchains, so generate it only once.
gen_dir = get_label_info(".($default_toolchain)", "target_gen_dir")
if (current_toolchain == default_toolchain) {
  assert(gen_dir == target_gen_dir)
  version_string_file = "$gen_dir/version-string.inc"
  if (kernel_version_string != "") {
    generated_file("version-string") {
      visibility = [ ":*" ]
      outputs = [ version_string_file ]
      contents = [
        "// Generated by $zx/kernel/lib/version/BUILD.gn.  DO NOT EDIT!",
        "constexpr char kVersionString[] = ",
        "    \"${kernel_version_string}\";",
      ]
    }
  } else {
    action("version-string") {
      visibility = [ ":*" ]
      script = "git-version-string.sh"
      outputs = [ version_string_file ]
      depfile = "$target_gen_dir/git-version-string.d"
      args = rebase_path([
                           version_string_file,
                           depfile,
                           "$zx/../.git",
                         ],
                         root_build_dir)
    }
  }
} else {
  zx_library("version") {
    kernel = true
    sources = [ "version.cc" ]
    defines = [ "ARCH=\"$current_cpu\"" ]
    include_dirs = [ gen_dir ]
    deps = [
      ":version-string($default_toolchain)",
      "$zx/kernel/lib/console",
    ]
  }
}