| # Copyright 2020 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. |
| """Emits an error telling the user not to use the default toolchain.""" |
| |
| import sys |
| |
| _ERROR_MESSAGE = """ |
| Error: trying to build a target with the default toolchain |
| |
| This occurs when a GN target is listed as a dependency outside of a toolchain |
| group (such as host_clang or stm32f429i) in the root BUILD.gn file. |
| |
| Make sure that your top-level targets are always instantiated with a toolchain |
| and that no dependencies are pulled in through the default toolchain. |
| |
| group("my_target_wrapper") { |
| deps = [ ":my_target(//path/to/my/toolchain)" ] |
| } |
| |
| group("my_target") { |
| deps = [] |
| if (current_toolchain != default_toolchain) { |
| deps += [ "//my_application:image" ] |
| } |
| } |
| |
| If you are developing in Pigweed itself, list your build target under one of |
| the predefined groups in //BUILD.gn. For example, |
| |
| # apps is an existing group intended for building application images. |
| group("apps") { |
| deps = [ |
| ... |
| "your_target:here", |
| ] |
| } |
| |
| Other predefined groups include host_tools, pw_modules, and pw_module_tests. |
| |
| If you want to add a custom group instead of using an existing one, it must be |
| defined alongside the predefined groups, within the toolchain condition block: |
| |
| if (current_toolchain != default_toolchain) { |
| group("apps") { |
| ... |
| } |
| |
| # Other predefined groups... |
| |
| group("my_custom_group") { |
| deps = [ "//path/to:my_target" ] |
| } |
| } |
| |
| To include your custom group in the build, add it to the pigweed_default group |
| to have it compile for every supported Pigweed target. |
| |
| group("pigweed_default") { |
| deps = [] |
| |
| if (current_toolchain != default_toolchain) { |
| # Standard Pigweed dependencies... |
| |
| # Add your group here. |
| deps += [ ":my_custom_group" ] |
| } |
| } |
| |
| For more details on the Pigweed build structure and how to configure custom |
| build targets or toolchains, please refer to "Build system" in the Pigweed |
| documentation. |
| """ |
| |
| |
| def main() -> int: |
| print(_ERROR_MESSAGE, file=sys.stderr) |
| return 1 |
| |
| |
| if __name__ == '__main__': |
| sys.exit(main()) |