| // Copyright 2022 The Bazel Authors. All rights reserved. |
| // |
| // 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. |
| |
| package com.google.devtools.build.lib.packages; |
| |
| import com.google.devtools.build.lib.cmdline.BazelModuleContext; |
| import com.google.devtools.build.lib.cmdline.Label; |
| import com.google.devtools.build.lib.cmdline.LabelSyntaxException; |
| import com.google.devtools.build.lib.cmdline.PackageIdentifier; |
| import com.google.devtools.build.lib.cmdline.RepositoryMapping; |
| import java.util.HashMap; |
| import java.util.Map; |
| import net.starlark.java.eval.Module; |
| import net.starlark.java.eval.StarlarkThread; |
| |
| /** |
| * Converts a label literal string into a {@link Label} object, using the appropriate base package |
| * and repo mapping. |
| */ |
| public class LabelConverter { |
| |
| /** |
| * Returns a label converter for the given thread, which MUST be evaluating a .bzl file. It uses |
| * the package containing the .bzl file as the base package, and the repo mapping of the repo |
| * containing the .bzl file. |
| */ |
| public static LabelConverter forBzlEvaluatingThread(StarlarkThread thread) { |
| BazelModuleContext moduleContext = |
| BazelModuleContext.of(Module.ofInnermostEnclosingStarlarkFunction(thread)); |
| return new LabelConverter(moduleContext.packageContext()); |
| } |
| |
| private final Label.PackageContext packageContext; |
| private final Map<String, Label> labelCache = new HashMap<>(); |
| |
| public LabelConverter(Label.PackageContext packageContext) { |
| this.packageContext = packageContext; |
| } |
| |
| /** Creates a label converter using the given base package and repo mapping. */ |
| public LabelConverter(PackageIdentifier base, RepositoryMapping repositoryMapping) { |
| this(Label.PackageContext.of(base, repositoryMapping)); |
| } |
| |
| /** Returns the base package identifier that relative labels will be resolved against. */ |
| PackageIdentifier getBasePackage() { |
| return packageContext.packageIdentifier(); |
| } |
| |
| /** Returns the Label corresponding to the input, using the current conversion context. */ |
| public Label convert(String input) throws LabelSyntaxException { |
| // Optimization: First check the package-local map, avoiding Label validation, Label |
| // construction, and global Interner lookup. This approach tends to be very profitable |
| // overall, since it's common for the targets in a single package to have duplicate |
| // label-strings across all their attribute values. |
| Label converted = labelCache.get(input); |
| if (converted == null) { |
| converted = Label.parseWithPackageContext(input, packageContext); |
| labelCache.put(input, converted); |
| } |
| return converted; |
| } |
| |
| @Override |
| public String toString() { |
| return getBasePackage().toString(); |
| } |
| } |