| // Copyright 2021 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.bazel.bzlmod; |
| |
| import static java.util.stream.Collectors.joining; |
| |
| import com.google.common.collect.ImmutableMap; |
| import com.google.devtools.build.lib.bazel.bzlmod.InterimModule.DepSpec; |
| import com.google.devtools.build.lib.bazel.bzlmod.ModuleFileValue.RootModuleFileValue; |
| import com.google.devtools.build.lib.server.FailureDetails; |
| import com.google.devtools.build.skyframe.SkyFunction.Environment; |
| import com.google.devtools.build.skyframe.SkyKey; |
| import com.google.devtools.build.skyframe.SkyframeLookupResult; |
| import java.util.ArrayDeque; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Queue; |
| import java.util.Set; |
| import javax.annotation.Nullable; |
| |
| /** |
| * Runs module discovery. This step of module resolution reads the module file of the root module |
| * (i.e. the current workspace), adds its direct {@code bazel_dep}s to the dependency graph, and |
| * repeats the step for any added dependencies until the entire graph is discovered. |
| */ |
| final class Discovery { |
| private Discovery() {} |
| |
| /** |
| * Runs module discovery. This function follows SkyFunction semantics (returns null if a Skyframe |
| * dependency is missing and this function needs a restart). |
| */ |
| @Nullable |
| public static ImmutableMap<ModuleKey, InterimModule> run( |
| Environment env, RootModuleFileValue root) |
| throws InterruptedException, ExternalDepsException { |
| String rootModuleName = root.getModule().getName(); |
| ImmutableMap<String, ModuleOverride> overrides = root.getOverrides(); |
| Map<ModuleKey, InterimModule> depGraph = new HashMap<>(); |
| depGraph.put(ModuleKey.ROOT, rewriteDepSpecs(root.getModule(), overrides, rootModuleName)); |
| Queue<ModuleKey> unexpanded = new ArrayDeque<>(); |
| Map<ModuleKey, ModuleKey> predecessors = new HashMap<>(); |
| unexpanded.add(ModuleKey.ROOT); |
| while (!unexpanded.isEmpty()) { |
| Set<SkyKey> unexpandedSkyKeys = new HashSet<>(); |
| while (!unexpanded.isEmpty()) { |
| InterimModule module = depGraph.get(unexpanded.remove()); |
| for (DepSpec depSpec : module.getDeps().values()) { |
| if (depGraph.containsKey(depSpec.toModuleKey())) { |
| continue; |
| } |
| predecessors.putIfAbsent(depSpec.toModuleKey(), module.getKey()); |
| unexpandedSkyKeys.add( |
| ModuleFileValue.key(depSpec.toModuleKey(), overrides.get(depSpec.getName()))); |
| } |
| } |
| SkyframeLookupResult result = env.getValuesAndExceptions(unexpandedSkyKeys); |
| for (SkyKey skyKey : unexpandedSkyKeys) { |
| ModuleKey depKey = ((ModuleFileValue.Key) skyKey).getModuleKey(); |
| ModuleFileValue moduleFileValue; |
| try { |
| moduleFileValue = |
| (ModuleFileValue) result.getOrThrow(skyKey, ExternalDepsException.class); |
| } catch (ExternalDepsException e) { |
| // Trace back a dependency chain to the root module. There can be multiple paths to the |
| // failing module, but any of those is useful for debugging. |
| List<ModuleKey> depChain = new ArrayList<>(); |
| depChain.add(depKey); |
| ModuleKey predecessor = depKey; |
| while ((predecessor = predecessors.get(predecessor)) != null) { |
| depChain.add(predecessor); |
| } |
| Collections.reverse(depChain); |
| String depChainString = |
| depChain.stream().map(ModuleKey::toString).collect(joining(" -> ")); |
| throw ExternalDepsException.withCauseAndMessage( |
| FailureDetails.ExternalDeps.Code.BAD_MODULE, |
| e, |
| "in module dependency chain %s", |
| depChainString); |
| } |
| if (moduleFileValue == null) { |
| // Don't return yet. Try to expand any other unexpanded nodes before returning. |
| depGraph.put(depKey, null); |
| } else { |
| depGraph.put( |
| depKey, rewriteDepSpecs(moduleFileValue.getModule(), overrides, rootModuleName)); |
| unexpanded.add(depKey); |
| } |
| } |
| } |
| if (env.valuesMissing()) { |
| return null; |
| } |
| return ImmutableMap.copyOf(depGraph); |
| } |
| |
| private static InterimModule rewriteDepSpecs( |
| InterimModule module, ImmutableMap<String, ModuleOverride> overrides, String rootModuleName) { |
| return module.withDepSpecsTransformed( |
| depSpec -> { |
| if (rootModuleName.equals(depSpec.getName())) { |
| return DepSpec.fromModuleKey(ModuleKey.ROOT); |
| } |
| |
| Version newVersion = depSpec.getVersion(); |
| @Nullable ModuleOverride override = overrides.get(depSpec.getName()); |
| if (override instanceof NonRegistryOverride) { |
| newVersion = Version.EMPTY; |
| } else if (override instanceof SingleVersionOverride) { |
| Version overrideVersion = ((SingleVersionOverride) override).getVersion(); |
| if (!overrideVersion.isEmpty()) { |
| newVersion = overrideVersion; |
| } |
| } |
| |
| return DepSpec.create(depSpec.getName(), newVersion, depSpec.getMaxCompatibilityLevel()); |
| }); |
| } |
| } |