| // Copyright 2023 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.docgen; |
| |
| import com.google.common.base.Preconditions; |
| import com.google.common.collect.ImmutableMap; |
| import com.google.devtools.build.lib.cmdline.Label; |
| import com.google.devtools.build.lib.cmdline.LabelSyntaxException; |
| import java.io.File; |
| import java.nio.file.Path; |
| import java.util.Map; |
| |
| /** |
| * Given a Build Encyclopedia generator tool's input filename or label, the mapper produces the URL |
| * for the corresponding source file in the source code repository. |
| */ |
| class SourceUrlMapper { |
| // TODO(arostovtsev): eventually, we will want to support multiple URL roots (e.g. for |
| // language-specific rules). |
| private final String sourceUrlRoot; |
| private final Path inputRoot; |
| private final ImmutableMap<String, String> labelRewrites; |
| |
| /** |
| * @param sourceUrlRoot root URL for the source code repository |
| * @param inputRoot input directory corresponding to the source tree root |
| * @param labelRewrites an ordered map of label string prefixes; a map entry of the form "foo" -> |
| * "bar" indicates that if a label string starts with "foo", that prefix should be replaced |
| * with "bar". The intended use case is transforming labels of .bzl files in @_builtins, whose |
| * corresponding source files live elsewhere in the repo. |
| */ |
| SourceUrlMapper( |
| String sourceUrlRoot, String inputRoot, ImmutableMap<String, String> labelRewrites) { |
| this.sourceUrlRoot = sourceUrlRoot; |
| this.inputRoot = new File(inputRoot).toPath(); |
| this.labelRewrites = labelRewrites; |
| } |
| |
| SourceUrlMapper(DocLinkMap linkMap, String inputRoot) { |
| this(linkMap.sourceUrlRoot, inputRoot, ImmutableMap.copyOf(linkMap.labelRewrites)); |
| } |
| |
| /** |
| * Returns the source code repository URL of a Java source file which was passed as an input to |
| * the Build Encyclopedia generator tool. |
| * |
| * @throws InvalidArgumentException if the URL could not be produced. |
| */ |
| String urlOfFile(File file) { |
| Path path = file.toPath(); |
| Preconditions.checkArgument( |
| path.startsWith(inputRoot), "File '%s' is expected to be under '%s'", path, inputRoot); |
| return sourceUrlRoot + inputRoot.toUri().relativize(path.toUri()); |
| } |
| |
| /** |
| * Returns the source code repository URL of a .bzl file label which was passed as an input to the |
| * Build Encyclopedia generator tool. |
| * |
| * <p>A label is first rewritten via {@link labelRewrites}: an entry of the form "foo" -> "bar" |
| * means that if {@code labelString} starts with "foo", the "foo" prefix is replaced with "bar". |
| * Rewrite rules in {@link labelRewrites} are examined in order, and only the first matching |
| * rewrite is applied. |
| * |
| * <p>If the result is a label in the main repo, the (possibly rewritten) label is transformed |
| * into a URL. |
| * |
| * @throws InvalidArgumentException if the URL could not be produced. |
| */ |
| String urlOfLabel(String labelString) { |
| String originalLabelString = labelString; |
| for (Map.Entry<String, String> entry : labelRewrites.entrySet()) { |
| if (labelString.startsWith(entry.getKey())) { |
| labelString = entry.getValue() + labelString.substring(entry.getKey().length()); |
| break; |
| } |
| } |
| Label label; |
| try { |
| label = Label.parseCanonical(labelString); |
| } catch (LabelSyntaxException e) { |
| String message = String.format("Failed to parse label '%s'", labelString); |
| if (!labelString.equals(originalLabelString)) { |
| message = String.format("%s (rewritten; originally '%s')", message, originalLabelString); |
| } |
| throw new IllegalArgumentException(message, e); |
| } |
| Preconditions.checkArgument( |
| label.getRepository().isMain(), "Label '%s' is not in the main repository", labelString); |
| |
| return sourceUrlRoot + label.toPathFragment().getPathString(); |
| } |
| } |