1# Copyright (C) 2022 The Android Open Source Project 2# 3# Licensed under the Apache License, Version 2.0 (the "License"); 4# you may not use this file except in compliance with the License. 5# You may obtain a copy of the License at 6# 7# http://www.apache.org/licenses/LICENSE-2.0 8# 9# Unless required by applicable law or agreed to in writing, software 10# distributed under the License is distributed on an "AS IS" BASIS, 11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12# See the License for the specific language governing permissions and 13# limitations under the License. 14 15# Bazel still resolves toolchains even if targets are marked incompatible with 16# target_compatible_with, which can cause failures due to the toolchain not being found. 17# To work around this issue, some rules make the toolchain optional, but then in their 18# impl functions assert that it exists. This helper function can do that assertion. 19def verify_toolchain_exists(ctx, toolchain): 20 if not ctx.toolchains[toolchain]: 21 # Mimic the bazel failure if this toolchain was mandatory 22 fail("While resolving toolchains for target %s: No matching toolchains found for types %s.\nTo debug, rerun with --toolchain_resolution_debug='%s'" % 23 (str(ctx.label), toolchain, toolchain)) 24