gn/perfetto_host_executable.gni

# Copyright (C) 2019 The Android Open Source Project
#
# 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
#
#      http://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("perfetto.gni")

# A template to make host tools handier. The main problem it solves is that when
# building host toolchain tools on an Android build, the executables end up in
# out/xxx/gcc_like_host, which is an inconvenient location. Our developers
# (and also some of our scripts) expect them to live in out/xxx/.
# This template takes care takes care of building the target only on the host
# toolchain and copy it over in the root build directory.
template("perfetto_host_executable") {
  if (is_perfetto_build_generator) {
    # On Android in-tree builds we don't need anything special in GN. However
    # remember to add the target to the |target_host_only| list in
    # tools/gen_android_bp to instruct the Android.bp generator.
    executable(target_name) {
      forward_variables_from(invoker, "*")
    }
  } else {
    if (current_toolchain == host_toolchain) {
      executable(target_name) {
        forward_variables_from(invoker, "*")
      }
    } else {
      not_needed(invoker, "*", [ "testonly" ])
      copy(target_name) {
        if (defined(invoker.testonly)) {
          testonly = invoker.testonly
        }
        host_target = ":$target_name($host_toolchain)"
        deps = [
          host_target,
        ]

        host_out_dir = get_label_info(host_target, "root_out_dir")
        sources = [
          "$host_out_dir/$target_name",
        ]
        outputs = [
          "$root_out_dir/$target_name",
        ]
      }
    }
  }  # if (is_perfetto_build_generator)
}