| """Rules for representing Rust toolchain channels""" |
| |
| _CHANNELS = [ |
| "beta", |
| "nightly", |
| "stable", |
| ] |
| |
| RustToolchainChannelInfo = provider( |
| doc = "A provider describing the Rust toolchain channel.", |
| fields = { |
| "value": "string: Can be {}".format(_CHANNELS), |
| }, |
| ) |
| |
| def _rust_toolchain_channel_flag_impl(ctx): |
| value = ctx.build_setting_value |
| if value not in _CHANNELS: |
| fail(str(ctx.label) + " build setting allowed to take values {" + |
| ", ".join(_CHANNELS) + "} but was set to unallowed value " + |
| value) |
| return RustToolchainChannelInfo(value = value) |
| |
| rust_toolchain_channel_flag = rule( |
| doc = "A build setting which represents the Rust toolchain channel. The allowed values are {}".format(_CHANNELS), |
| implementation = _rust_toolchain_channel_flag_impl, |
| build_setting = config.string( |
| flag = True, |
| ), |
| ) |
