xref: /aosp_15_r20/build/bazel/rules/toolchain_utils.bzl (revision 7594170e27e0732bc44b93d1440d87a54b6ffe7c)
1*7594170eSAndroid Build Coastguard Worker# Copyright (C) 2022 The Android Open Source Project
2*7594170eSAndroid Build Coastguard Worker#
3*7594170eSAndroid Build Coastguard Worker# Licensed under the Apache License, Version 2.0 (the "License");
4*7594170eSAndroid Build Coastguard Worker# you may not use this file except in compliance with the License.
5*7594170eSAndroid Build Coastguard Worker# You may obtain a copy of the License at
6*7594170eSAndroid Build Coastguard Worker#
7*7594170eSAndroid Build Coastguard Worker#     http://www.apache.org/licenses/LICENSE-2.0
8*7594170eSAndroid Build Coastguard Worker#
9*7594170eSAndroid Build Coastguard Worker# Unless required by applicable law or agreed to in writing, software
10*7594170eSAndroid Build Coastguard Worker# distributed under the License is distributed on an "AS IS" BASIS,
11*7594170eSAndroid Build Coastguard Worker# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12*7594170eSAndroid Build Coastguard Worker# See the License for the specific language governing permissions and
13*7594170eSAndroid Build Coastguard Worker# limitations under the License.
14*7594170eSAndroid Build Coastguard Worker
15*7594170eSAndroid Build Coastguard Worker# Bazel still resolves toolchains even if targets are marked incompatible with
16*7594170eSAndroid Build Coastguard Worker# target_compatible_with, which can cause failures due to the toolchain not being found.
17*7594170eSAndroid Build Coastguard Worker# To work around this issue, some rules make the toolchain optional, but then in their
18*7594170eSAndroid Build Coastguard Worker# impl functions assert that it exists. This helper function can do that assertion.
19*7594170eSAndroid Build Coastguard Workerdef verify_toolchain_exists(ctx, toolchain):
20*7594170eSAndroid Build Coastguard Worker    if not ctx.toolchains[toolchain]:
21*7594170eSAndroid Build Coastguard Worker        # Mimic the bazel failure if this toolchain was mandatory
22*7594170eSAndroid Build Coastguard Worker        fail("While resolving toolchains for target %s: No matching toolchains found for types %s.\nTo debug, rerun with --toolchain_resolution_debug='%s'" %
23*7594170eSAndroid Build Coastguard Worker             (str(ctx.label), toolchain, toolchain))
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