pw_build/rust_bindgen_action.gni

# Copyright 2024 The Pigweed Authors
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may not
# use this file except in compliance with the License. You may obtain a copy of
# the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations under
# the License.
import("//build_overrides/pigweed.gni")
import("//build_overrides/pigweed_environment.gni")
import("$dir_pw_build/exec.gni")

_bindgen_exe_path =
    rebase_path(pw_env_setup_CIPD_PIGWEED + "/rust_bindgen/bindgen")

# Bindgen is not part of GN tools, so use pw_exec to run it.
template("rust_bindgen_action") {
  pw_exec(target_name) {
    forward_variables_from(invoker,
                           [
                             "cflags",
                             "cflags_c",
                             "configs",
                             "defines",
                             "deps",
                             "public_configs",
                             "public_deps",
                             "visibility",
                           ])
    not_needed(invoker, "*")

    output_gen_rs = "$target_gen_dir/${target_name}.rs"

    program = _bindgen_exe_path
    header = rebase_path(invoker.header, root_build_dir)

    if (defined(invoker.libclang_path)) {
      # Note `-isysroot` may not work properly when `LIBCLANG_PATH` is set.
      env = [ "LIBCLANG_PATH=" + invoker.libclang_path ]
    }

    outputs = [ output_gen_rs ]
    depfile = "$target_out_dir/${target_name}.d"
    args = [
      "--depfile",
      rebase_path(depfile, root_build_dir),
      "--output",
      rebase_path(output_gen_rs, root_build_dir),
    ]

    args += [
      # Do not search for system default include paths.
      "--no-include-path-detection",
    ]
    if (defined(invoker.flags)) {
      foreach(flag, invoker.flags) {
        args += [ flag ]
      }
    }

    args += [
      header,
      "--",
      "{{defines}}",
      "{{include_dirs}}",
      "{{cflags}}",
      "{{cflags_c}}",
    ]
  }
}