build/python/python_c_extension.gni

# Copyright 2023 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import("//build/python/python_c_extension_shared_lib.gni")
import("//build/python/python_library.gni")

# Defines a python C extension library.
#
# This can be imported into a `.pyz` library, but the user must make sure the
# .so that this is appending to the path is located in the output build directory,
# as this will be appending to PYTHONPATH.

template("python_c_extension") {
  assert(is_host, "python C extensions can only be built on the host")

  c_sources = invoker.sources
  c_deps = invoker.deps
  shlib_target_name = target_name + "_shlib"
  main_target_name = target_name
  python_c_extension_shared_lib(shlib_target_name) {
    library_name = main_target_name
    forward_variables_from(invoker,
                           [
                             "assert_no_deps",
                             "configs",
                             "testonly",
                           ])
    sources = c_sources
    deps = c_deps
  }

  action(target_name + "_wrapper") {
    forward_variables_from(invoker,
                           [
                             "testonly",
                             "visibility",
                           ])
    deps = [ ":" + shlib_target_name ]
    script = "//build/python/create_c_extension_import_hook.py"
    depfile = "${target_out_dir}/${target_name}.d"
    _output = "${target_gen_dir}/${target_name}/__init__.py"
    outputs = [ _output ]
    args = [
      "--target_name",
      target_name,
      "--shlib_source",
      rebase_path(main_target_name, root_build_dir, root_out_dir),
      "--gen_dir",
      rebase_path(target_gen_dir, root_build_dir),
      "--output",
      rebase_path(_output, root_build_dir),
      "--depfile",
      rebase_path(depfile, root_build_dir),
    ]
  }

  python_library(target_name) {
    forward_variables_from(invoker,
                           [
                             "testonly",
                             "visibility",
                           ])
    deps = [ ":" + target_name + "_wrapper" ]
    source_root = "${target_gen_dir}/" + target_name + "_wrapper"
    sources = [ "__init__.py" ]
    enable_mypy = true
  }
}

set_defaults("python_c_extension") {
  configs = default_shared_library_configs
}