|  | // Copyright 2014 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.skyframe; | 
|  |  | 
|  | import com.github.benmanes.caffeine.cache.Cache; | 
|  | import com.github.benmanes.caffeine.cache.Caffeine; | 
|  | import com.google.common.base.Preconditions; | 
|  | import com.google.common.base.Predicates; | 
|  | import com.google.common.collect.ImmutableList; | 
|  | import com.google.common.collect.ImmutableMap; | 
|  | import com.google.common.collect.Lists; | 
|  | import com.google.common.collect.Maps; | 
|  | import com.google.common.flogger.GoogleLogger; | 
|  | import com.google.common.hash.HashFunction; | 
|  | import com.google.devtools.build.lib.analysis.BlazeDirectories; | 
|  | import com.google.devtools.build.lib.cmdline.Label; | 
|  | import com.google.devtools.build.lib.cmdline.LabelConstants; | 
|  | import com.google.devtools.build.lib.cmdline.LabelSyntaxException; | 
|  | import com.google.devtools.build.lib.cmdline.PackageIdentifier; | 
|  | import com.google.devtools.build.lib.cmdline.RepositoryName; | 
|  | import com.google.devtools.build.lib.concurrent.BlazeInterners; | 
|  | import com.google.devtools.build.lib.events.Event; | 
|  | import com.google.devtools.build.lib.events.EventHandler; | 
|  | import com.google.devtools.build.lib.events.ExtendedEventHandler; | 
|  | import com.google.devtools.build.lib.events.ExtendedEventHandler.Postable; | 
|  | import com.google.devtools.build.lib.events.StoredEventHandler; | 
|  | import com.google.devtools.build.lib.io.InconsistentFilesystemException; | 
|  | import com.google.devtools.build.lib.packages.BazelModuleContext; | 
|  | import com.google.devtools.build.lib.packages.BazelStarlarkEnvironment; | 
|  | import com.google.devtools.build.lib.packages.BuildFileNotFoundException; | 
|  | import com.google.devtools.build.lib.packages.PackageFactory; | 
|  | import com.google.devtools.build.lib.packages.StarlarkExportable; | 
|  | import com.google.devtools.build.lib.packages.WorkspaceFileValue; | 
|  | import com.google.devtools.build.lib.packages.semantics.BuildLanguageOptions; | 
|  | import com.google.devtools.build.lib.server.FailureDetails.FailureDetail; | 
|  | import com.google.devtools.build.lib.server.FailureDetails.StarlarkLoading; | 
|  | import com.google.devtools.build.lib.server.FailureDetails.StarlarkLoading.Code; | 
|  | import com.google.devtools.build.lib.skyframe.StarlarkBuiltinsFunction.BuiltinsFailedException; | 
|  | import com.google.devtools.build.lib.util.DetailedExitCode; | 
|  | import com.google.devtools.build.lib.util.Fingerprint; | 
|  | import com.google.devtools.build.lib.util.Pair; | 
|  | import com.google.devtools.build.lib.vfs.PathFragment; | 
|  | import com.google.devtools.build.lib.vfs.Root; | 
|  | import com.google.devtools.build.skyframe.RecordingSkyFunctionEnvironment; | 
|  | import com.google.devtools.build.skyframe.SkyFunction; | 
|  | import com.google.devtools.build.skyframe.SkyFunctionException; | 
|  | import com.google.devtools.build.skyframe.SkyFunctionException.Transience; | 
|  | import com.google.devtools.build.skyframe.SkyKey; | 
|  | import com.google.devtools.build.skyframe.SkyValue; | 
|  | import com.google.devtools.build.skyframe.ValueOrException; | 
|  | import java.util.HashMap; | 
|  | import java.util.HashSet; | 
|  | import java.util.LinkedHashSet; | 
|  | import java.util.List; | 
|  | import java.util.Map; | 
|  | import java.util.function.Consumer; | 
|  | import javax.annotation.Nullable; | 
|  | import net.starlark.java.eval.EvalException; | 
|  | import net.starlark.java.eval.Module; | 
|  | import net.starlark.java.eval.Mutability; | 
|  | import net.starlark.java.eval.Starlark; | 
|  | import net.starlark.java.eval.StarlarkSemantics; | 
|  | import net.starlark.java.eval.StarlarkThread; | 
|  | import net.starlark.java.syntax.LoadStatement; | 
|  | import net.starlark.java.syntax.Location; | 
|  | import net.starlark.java.syntax.Program; | 
|  | import net.starlark.java.syntax.StarlarkFile; | 
|  | import net.starlark.java.syntax.Statement; | 
|  | import net.starlark.java.syntax.StringLiteral; | 
|  |  | 
|  | /** | 
|  | * A Skyframe function to look up and load a single .bzl module. | 
|  | * | 
|  | * <p>Given a {@link Label} referencing a .bzl file, attempts to locate the file and load it. The | 
|  | * Label must be absolute, and must not reference the special {@code external} package. If loading | 
|  | * is successful, returns a {@link BzlLoadValue} that encapsulates the loaded {@link Module} and its | 
|  | * transitive digest information. If loading is unsuccessful, throws a {@link | 
|  | * BzlLoadFunctionException} that encapsulates the cause of the failure. | 
|  | * | 
|  | * <p>This Skyframe function supports a special bzl "inlining" mode in which all (indirectly) | 
|  | * recursive calls to {@code BzlLoadFunction} are made in the same thread rather than through | 
|  | * Skyframe. This inlining mode's entry point is {@link #computeInline}; see that method for more | 
|  | * details. Note that it may only be called on an instance of this Skyfunction created by {@link | 
|  | * #createForInlining}. Bzl inlining is not to be confused with the separate inlining of {@code | 
|  | * BzlCompileFunction} | 
|  | */ | 
|  | public class BzlLoadFunction implements SkyFunction { | 
|  |  | 
|  | // Used for: 1) obtaining a RuleClassProvider to create the BazelStarlarkContext for Starlark | 
|  | // evaluation; 2) providing predeclared environments to other Skyfunctions | 
|  | // (StarlarkBuiltinsFunction, BzlCompileFunction) when they are inlined and called via a static | 
|  | // computeInline() entry point. | 
|  | private final PackageFactory packageFactory; | 
|  |  | 
|  | // Used for determining paths to builtins bzls that live in the workspace. | 
|  | private final BlazeDirectories directories; | 
|  |  | 
|  | // Handles retrieving BzlCompileValues, either by calling Skyframe or by inlining | 
|  | // BzlCompileFunction; the latter is not to be confused with inlining of BzlLoadFunction. See | 
|  | // comment in create() for rationale. | 
|  | private final ValueGetter getter; | 
|  |  | 
|  | // Handles inlining of BzlLoadFunction calls. | 
|  | @Nullable private final CachedBzlLoadDataManager cachedBzlLoadDataManager; | 
|  |  | 
|  | private static final GoogleLogger logger = GoogleLogger.forEnclosingClass(); | 
|  |  | 
|  | private BzlLoadFunction( | 
|  | PackageFactory packageFactory, | 
|  | BlazeDirectories directories, | 
|  | ValueGetter getter, | 
|  | @Nullable CachedBzlLoadDataManager cachedBzlLoadDataManager) { | 
|  | this.packageFactory = packageFactory; | 
|  | this.directories = directories; | 
|  | this.getter = getter; | 
|  | this.cachedBzlLoadDataManager = cachedBzlLoadDataManager; | 
|  | } | 
|  |  | 
|  | public static BzlLoadFunction create( | 
|  | PackageFactory packageFactory, | 
|  | BlazeDirectories directories, | 
|  | HashFunction hashFunction, | 
|  | Cache<BzlCompileValue.Key, BzlCompileValue> bzlCompileCache) { | 
|  | return new BzlLoadFunction( | 
|  | packageFactory, | 
|  | directories, | 
|  | // When we are not inlining BzlLoadValue nodes, there is no need to have separate | 
|  | // BzlCompileValue nodes for bzl files. Instead we inline BzlCompileFunction for a | 
|  | // strict memory win, at a small code complexity cost. | 
|  | // | 
|  | // Detailed explanation: | 
|  | // (1) The BzlCompileValue node for a bzl file is used only for the computation of | 
|  | // that file's BzlLoadValue node. So there's no concern about duplicate work that would | 
|  | // otherwise get deduped by Skyframe. | 
|  | // (2) BzlCompileValue doesn't have an interesting equality relation, so we have no | 
|  | // hope of getting any interesting change-pruning of BzlCompileValue nodes. If we | 
|  | // had an interesting equality relation that was e.g. able to ignore benign | 
|  | // whitespace, then there would be a hypothetical benefit to having separate | 
|  | // BzlCompileValue nodes (e.g. on incremental builds we'd be able to not re-execute | 
|  | // top-level code in bzl files if the file were reparsed to an equivalent tree). | 
|  | // TODO(adonovan): this will change once it truly compiles the code (soon). | 
|  | // (3) A BzlCompileValue node lets us avoid redoing work on a BzlLoadFunction Skyframe | 
|  | // restart, but we can also achieve that result ourselves with a cache that persists between | 
|  | // Skyframe restarts. | 
|  | // | 
|  | // Therefore, BzlCompileValue nodes are wasteful from two perspectives: | 
|  | // (a) BzlCompileValue contains syntax trees, and that business object is really | 
|  | // just a temporary thing for bzl execution. Retaining it forever is pure waste. | 
|  | // (b) The memory overhead of the extra Skyframe node and edge per bzl file is pure | 
|  | // waste. | 
|  | new InliningAndCachingGetter(packageFactory, hashFunction, bzlCompileCache), | 
|  | /*cachedBzlLoadDataManager=*/ null); | 
|  | } | 
|  |  | 
|  | public static BzlLoadFunction createForInlining( | 
|  | PackageFactory packageFactory, BlazeDirectories directories, int bzlLoadValueCacheSize) { | 
|  | return new BzlLoadFunction( | 
|  | packageFactory, | 
|  | directories, | 
|  | // When we are inlining BzlLoadValue nodes, then we want to have explicit BzlCompileValue | 
|  | // nodes, since now (1) in the comment above doesn't hold. This way we read and parse each | 
|  | // needed bzl file at most once total globally, rather than once per need (in the worst-case | 
|  | // of a BzlLoadValue inlining cache miss). This is important in the situation where a bzl | 
|  | // file is loaded by a lot of other bzl files or BUILD files. | 
|  | RegularSkyframeGetter.INSTANCE, | 
|  | new CachedBzlLoadDataManager(bzlLoadValueCacheSize)); | 
|  | } | 
|  |  | 
|  | @Override | 
|  | @Nullable | 
|  | public SkyValue compute(SkyKey skyKey, Environment env) | 
|  | throws SkyFunctionException, InterruptedException { | 
|  | BzlLoadValue.Key key = (BzlLoadValue.Key) skyKey.argument(); | 
|  | try { | 
|  | return computeInternal(key, env, /*inliningState=*/ null); | 
|  | } catch (BzlLoadFailedException e) { | 
|  | throw new BzlLoadFunctionException(e); | 
|  | } | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Entry point for computing "inline", without any direct or indirect Skyframe calls back into | 
|  | * {@link BzlLoadFunction}. (Other Skyframe calls are permitted.) | 
|  | * | 
|  | * <p><b>USAGE NOTES:</b> | 
|  | * | 
|  | * <ul> | 
|  | *   <li>This method is intended to be called from {@link PackageFunction} and {@link | 
|  | *       StarlarkBuiltinsFunction} and probably shouldn't be used anywhere else. If you think you | 
|  | *       need inline Starlark computation, consult with the Core subteam and check out | 
|  | *       cl/305127325 for an example of correcting a misuse. | 
|  | *   <li>If this method is used with --keep_going and if Skyframe evaluation will never be | 
|  | *       interrupted, then this function ensures that the evaluation graph and any error reported | 
|  | *       are deterministic. | 
|  | * </ul> | 
|  | * | 
|  | * <p>Under bzl inlining, there is some calling context that wants to obtain a set of {@link | 
|  | * BzlLoadValue}s without Skyframe evaluation. For example, a calling context can be a BUILD file | 
|  | * trying to resolve its top-level {@code load} statements. Although this work proceeds in a | 
|  | * single thread, multiple calling contexts may evaluate .bzls in parallel. To avoid redundant | 
|  | * work, they share a single (global to this Skyfunction instance) cache in lieu of the regular | 
|  | * Skyframe cache. Unlike the regular Skyframe cache, this cache stores only successes. | 
|  | * | 
|  | * <p>If two calling contexts race to compute the same .bzl, each one will see a different copy of | 
|  | * it, and only one will end up in the shared cache. This presents a hazard: Suppose A and B both | 
|  | * need foo.bzl, and A needs it twice due to a diamond dependency. If A and B race to compute | 
|  | * foo.bzl, but B's computation populates the cache, then when A comes back to resolve it the | 
|  | * second time it will observe a different {@code BzlLoadValue}. This leads to incorrect Starlark | 
|  | * evaluation since Starlark values may rely on Java object identity (see b/138598337). Even if we | 
|  | * weren't concerned about racing, A may also reevaluate previously computed items due to cache | 
|  | * evictions. | 
|  | * | 
|  | * <p>To solve this, we keep a second cache, {@link InliningState#successfulLoads}, that is local | 
|  | * to the current calling context, and which never evicts entries. Like the global cache discussed | 
|  | * above, this cache stores only successes. This cache is always checked in preference to the | 
|  | * shared one; it may deviate from the shared one in some of its entries, but the calling context | 
|  | * won't know the difference. (Since bzl inlining is only used for the loading phase, we don't | 
|  | * need to worry about Starlark values from different packages interacting.) The cache is stored | 
|  | * as part of the {@code inliningState} passed in by the caller; the caller can obtain this object | 
|  | * using {@link InliningState#create}. | 
|  | * | 
|  | * <p>As an aside, note that we can't avoid having {@link InliningState#successfulLoads} by simply | 
|  | * naively blocking evaluation of .bzls on retrievals from the shared cache. This is because two | 
|  | * contexts could deadlock while trying to evaluate an illegal {@code load()} cycle from opposite | 
|  | * ends. It would be possible to construct a waits-for graph and perform cycle detection, or to | 
|  | * monitor slow threads and do detection lazily, but these do not address the cache eviction | 
|  | * issue. Alternatively, we could make Starlark tolerant of reloading, but that would be | 
|  | * tantamount to implementing full Starlark serialization. | 
|  | * | 
|  | * <p>Since our local {@link InliningState#successfulLoads} stores only successes, a separate | 
|  | * concern is that we don't want to unsuccessfully visit the same .bzl more than once in the same | 
|  | * context. (A visitation is unsuccessful if it fails due to an error or if it cannot complete | 
|  | * because of a missing Skyframe dep.) To address this concern we maintain a separate {@link | 
|  | * InliningState#unsuccessfulLoads} set, and use this set to return null instead of duplicating an | 
|  | * unsuccessful visitation. | 
|  | * | 
|  | * @return the requested {@code BzlLoadValue}, or null if there was a missing Skyframe dep, an | 
|  | *     unspecified exception in a Skyframe dep request, or if this was a duplicate unsuccessful | 
|  | *     visitation | 
|  | */ | 
|  | // TODO(brandjon): Pick one of the nouns "load" and "bzl" and use that term consistently. | 
|  | @Nullable | 
|  | BzlLoadValue computeInline(BzlLoadValue.Key key, InliningState inliningState) | 
|  | throws BzlLoadFailedException, InterruptedException { | 
|  | Preconditions.checkNotNull(cachedBzlLoadDataManager); | 
|  | CachedBzlLoadData cachedData = computeInlineCachedData(key, inliningState); | 
|  | return cachedData != null ? cachedData.getValue() : null; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Retrieves or creates the requested {@link CachedBzlLoadData} object for the given bzl, entering | 
|  | * it into the local and shared caches. This is the entry point for recursive calls to the inline | 
|  | * code path. | 
|  | * | 
|  | * @return null if there was a missing Skyframe dep, an unspecified exception in a Skyframe dep | 
|  | *     request, or if this was a duplicate unsuccessful visitation | 
|  | */ | 
|  | @Nullable | 
|  | private CachedBzlLoadData computeInlineCachedData( | 
|  | BzlLoadValue.Key key, InliningState inliningState) | 
|  | throws BzlLoadFailedException, InterruptedException { | 
|  | // Try the caches of successful loads. We must try the thread-local cache before the shared, for | 
|  | // consistency purposes (see the javadoc of #computeInline). | 
|  | CachedBzlLoadData cachedData = inliningState.successfulLoads.get(key); | 
|  | if (cachedData == null) { | 
|  | cachedData = cachedBzlLoadDataManager.cache.getIfPresent(key); | 
|  | if (cachedData != null) { | 
|  | // Found a cache hit from another thread's computation. Register the cache hit's recorded | 
|  | // deps as if we had requested them directly in the unwrapped environment. We do this for | 
|  | // the unwrapped environment, not the recording environment, because there's no need to | 
|  | // embed one CachedBzlLoadData's metadata inside another; the dependency relationship will | 
|  | // still be accurately reflected in the cache by the call to addTransitiveDeps() via | 
|  | // childCachedDataHandler at the bottom of this function. | 
|  | // | 
|  | // Also incorporate into successfulLoads any transitive cache hits that it does not already | 
|  | // contains. | 
|  | cachedData.traverse( | 
|  | inliningState.recordingEnv.getDelegate()::registerDependencies, | 
|  | inliningState.successfulLoads); | 
|  | } | 
|  | } | 
|  |  | 
|  | // See if we've already unsuccessfully visited the bzl. "Unsuccessfully" includes getting null | 
|  | // for a missing Skyframe dep; the top-level caller will use a fresh InliningState when it does | 
|  | // its Skyframe restart. | 
|  | if (inliningState.unsuccessfulLoads.contains(key)) { | 
|  | return null; | 
|  | } | 
|  |  | 
|  | // If we're here, the bzl must have never been visited before in this calling context. Compute | 
|  | // it ourselves, updating the other data structures as appropriate. | 
|  | if (cachedData == null) { | 
|  | try { | 
|  | cachedData = computeInlineForCacheMiss(key, inliningState); | 
|  | } finally { | 
|  | if (cachedData != null) { | 
|  | inliningState.successfulLoads.put(key, cachedData); | 
|  | cachedBzlLoadDataManager.cache.put(key, cachedData); | 
|  | } else { | 
|  | inliningState.unsuccessfulLoads.add(key); | 
|  | // Either propagate an exception or fall through for null return. | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | // On success (from cache hit or from scratch), notify the parent CachedBzlLoadData of its new | 
|  | // child. | 
|  | if (cachedData != null) { | 
|  | inliningState.childCachedDataHandler.accept(cachedData); | 
|  | } | 
|  |  | 
|  | return cachedData; | 
|  | } | 
|  |  | 
|  | @Nullable | 
|  | private CachedBzlLoadData computeInlineForCacheMiss( | 
|  | BzlLoadValue.Key key, InliningState inliningState) | 
|  | throws BzlLoadFailedException, InterruptedException { | 
|  | // We use an instrumented Skyframe env to capture Skyframe deps in the CachedBzlLoadData (see | 
|  | // InliningState#recordingEnv). This generally includes transitive Skyframe deps, but | 
|  | // specifically excludes deps underneath recursively loaded .bzls. In this way, the | 
|  | // CachedBzlLoadData objects form a DAG that mirrors the bzl load graph: Each node still reaches | 
|  | // *all* the transitive skyframe deps needed for its computation, but the bzl-level granularity | 
|  | // allows for sharing of cached results for portions of the bzl load graph. | 
|  | // | 
|  | // Here we are at the boundary between one CachedBzlLoadData and the next. createChildState() | 
|  | // unwraps the old recording env and starts a new one for a new node. | 
|  |  | 
|  | InliningState childState = inliningState.createChildState(cachedBzlLoadDataManager); | 
|  | childState.beginLoad(key); // track for cyclic load() detection | 
|  | BzlLoadValue value; | 
|  | try { | 
|  | value = computeInternal(key, childState.recordingEnv, childState); | 
|  | } finally { | 
|  | childState.finishLoad(key); | 
|  | } | 
|  | if (value == null) { | 
|  | return null; | 
|  | } | 
|  |  | 
|  | return childState.buildCachedData(key, value); | 
|  | } | 
|  |  | 
|  | public void resetInliningCache() { | 
|  | cachedBzlLoadDataManager.reset(); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * An opaque object that holds state for the bzl inlining computation initiated by {@link | 
|  | * #computeInline}. | 
|  | * | 
|  | * <p>An original caller of {@code computeInline} (e.g., {@link PackageFunction}) should obtain | 
|  | * one of these objects using {@link InliningState#create}. When the same caller makes several | 
|  | * calls to {@code computeInline} (e.g., for multiple top-level loads in the same BUILD file), the | 
|  | * same object must be passed to each call. | 
|  | * | 
|  | * <p>When a Skyfunction that is called by {@code BzlLoadFunction}'s inlining code path in turn | 
|  | * calls back into {@code computeInline}, it should forward along the same {@code InliningState} | 
|  | * that it received. In particular, {@link StarlarkBuiltinsFunction} forwards the inlining state | 
|  | * to ensure that 1) the .bzls that get loaded from the {@code @_builtins} pseudo-repository are | 
|  | * properly recorded as dependencies of all .bzl files that use builtins injection, and 2) the | 
|  | * builtins .bzls are not reevaluated. | 
|  | */ | 
|  | // TODO(brandjon): Consider making this even more opaque and encapsulating more of the details of | 
|  | // inlining. E.g., merge beginLoad/finishLoad with child state tracking, and encapsulate | 
|  | // management of [un]successfulLoads. | 
|  | static class InliningState { | 
|  |  | 
|  | /** | 
|  | * The Skyframe environment, instrumented to record dependencies inside CachedBzlLoadData | 
|  | * objects. A new CachedBzlLoadData, and therefore a new recording environment, is started in | 
|  | * each call to computeInlineForCacheMiss(). The initial InliningState's recording environment | 
|  | * doesn't instrument anything since it represents the piece of the work that will not be saved | 
|  | * in any CachedBzlLoadData. | 
|  | */ | 
|  | private final RecordingSkyFunctionEnvironment recordingEnv; | 
|  |  | 
|  | /** | 
|  | * The builder of the CachedBzlLoadData node that we are currently working on, if any. Null iff | 
|  | * we're the initial InliningState, where recordingEnv doesn't instrument anything. | 
|  | */ | 
|  | private final CachedBzlLoadData.Builder cachedDataBuilder; | 
|  |  | 
|  | /** | 
|  | * The set of bzls we're currently in the process of loading but haven't fully visited yet. This | 
|  | * is used for cycle detection since we don't have the benefit of Skyframe's internal cycle | 
|  | * detection. The set must use insertion order for correct error reporting. | 
|  | * | 
|  | * <p>This is disjoint with {@link #successfulLoads} and {@link #unsuccessfulLoads}. | 
|  | * | 
|  | * <p>This is local to current calling context. See {@link #computeInline}. | 
|  | */ | 
|  | // Keyed on the SkyKey, not the label, since label could theoretically be ambiguous, even though | 
|  | // in practice keys from BUILD / WORKSPACE / builtins don't call each other. (Not sure if | 
|  | // WORKSPACE chunking can cause duplicate labels to appear, but we're robust regardless.) | 
|  | private final LinkedHashSet<BzlLoadValue.Key> loadStack; | 
|  |  | 
|  | /** | 
|  | * Cache of bzls that have been fully visited and successfully loaded to a value. | 
|  | * | 
|  | * <p>This and {@link #unsuccessfulLoads} partition the set of fully visited bzls. | 
|  | * | 
|  | * <p>This is local to current calling context. See {@link #computeInline}. | 
|  | */ | 
|  | private final Map<BzlLoadValue.Key, CachedBzlLoadData> successfulLoads; | 
|  |  | 
|  | /** | 
|  | * Set of bzls that have been fully visited, but were not successfully loaded to a value. | 
|  | * | 
|  | * <p>This and {@link #successfulLoads} partition the set of fully visited bzls, and is disjoint | 
|  | * with {@link #loadStack}. | 
|  | * | 
|  | * <p>This is local to current calling context. See {@link #computeInline}. | 
|  | */ | 
|  | private final HashSet<BzlLoadValue.Key> unsuccessfulLoads; | 
|  |  | 
|  | /** Called when a transitive {@code CachedBzlLoadData} is produced. */ | 
|  | private final Consumer<CachedBzlLoadData> childCachedDataHandler; | 
|  |  | 
|  | private InliningState( | 
|  | RecordingSkyFunctionEnvironment recordingEnv, | 
|  | CachedBzlLoadData.Builder cachedDataBuilder, | 
|  | LinkedHashSet<BzlLoadValue.Key> loadStack, | 
|  | Map<BzlLoadValue.Key, CachedBzlLoadData> successfulLoads, | 
|  | HashSet<BzlLoadValue.Key> unsuccessfulLoads, | 
|  | Consumer<CachedBzlLoadData> childCachedDataHandler) { | 
|  | this.recordingEnv = recordingEnv; | 
|  | this.cachedDataBuilder = cachedDataBuilder; | 
|  | this.loadStack = loadStack; | 
|  | this.successfulLoads = successfulLoads; | 
|  | this.unsuccessfulLoads = unsuccessfulLoads; | 
|  | this.childCachedDataHandler = childCachedDataHandler; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Creates an initial {@code InliningState} with no information about previously loaded files | 
|  | * (except the shared cache stored in {@link BzlLoadFunction}). | 
|  | */ | 
|  | static InliningState create(Environment env) { | 
|  | return new InliningState( | 
|  | new RecordingSkyFunctionEnvironment(env, x -> {}, x -> {}, x -> {}), | 
|  | /*cachedDataBuilder=*/ null, | 
|  | /*loadStack=*/ new LinkedHashSet<>(), | 
|  | /*successfulLoads=*/ new HashMap<>(), | 
|  | /*unsuccessfulLoads=*/ new HashSet<>(), | 
|  | // No parent value to mutate | 
|  | /*childCachedDataHandler=*/ x -> {}); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Creates another InliningState from this one, but with the recording Skyframe environment set | 
|  | * up to log dependency metadata into a CachedBzlLoadData node that is a child of this | 
|  | * InliningState's node. | 
|  | */ | 
|  | private InliningState createChildState(CachedBzlLoadDataManager cachedBzlLoadDataManager) { | 
|  | CachedBzlLoadData.Builder newBuilder = cachedBzlLoadDataManager.cachedDataBuilder(); | 
|  | RecordingSkyFunctionEnvironment newRecordingEnv = | 
|  | new RecordingSkyFunctionEnvironment( | 
|  | recordingEnv.getDelegate(), | 
|  | newBuilder::addDep, | 
|  | newBuilder::addDeps, | 
|  | newBuilder::noteException); | 
|  | return new InliningState( | 
|  | newRecordingEnv, | 
|  | newBuilder, | 
|  | loadStack, | 
|  | successfulLoads, | 
|  | unsuccessfulLoads, | 
|  | newBuilder::addTransitiveDeps); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Finishes construction of the current CachedBzlLoadData node. This InliningState object should | 
|  | * not be used after calling this method. | 
|  | */ | 
|  | private CachedBzlLoadData buildCachedData(BzlLoadValue.Key key, BzlLoadValue value) { | 
|  | cachedDataBuilder.setValue(value); | 
|  | cachedDataBuilder.setKey(key); | 
|  | return cachedDataBuilder.build(); | 
|  | } | 
|  |  | 
|  | /** Records entry to a {@code load()}, throwing an exception if a cycle is detected. */ | 
|  | private void beginLoad(BzlLoadValue.Key key) throws BzlLoadFailedException { | 
|  | if (!loadStack.add(key)) { | 
|  | ImmutableList<BzlLoadValue.Key> cycle = | 
|  | CycleUtils.splitIntoPathAndChain(Predicates.equalTo(key), loadStack).second; | 
|  | throw new BzlLoadFailedException("Starlark load cycle: " + cycle, Code.CYCLE); | 
|  | } | 
|  | } | 
|  |  | 
|  | /** Records exit from a {@code load()}. */ | 
|  | private void finishLoad(BzlLoadValue.Key key) throws BzlLoadFailedException { | 
|  | Preconditions.checkState(loadStack.remove(key), key); | 
|  | } | 
|  |  | 
|  | /** Retrieves the Skyframe environment to use to do work under this InliningState. */ | 
|  | Environment getEnvironment() { | 
|  | return recordingEnv; | 
|  | } | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Entry point for compute logic that's common to both (bzl) inlining and non-inlining code paths. | 
|  | */ | 
|  | // It is vital that we don't return any value if any call to env#getValue(s)OrThrow throws an | 
|  | // exception. We are allowed to wrap the thrown exception and rethrow it for any calling functions | 
|  | // to handle though. | 
|  | @Nullable | 
|  | private BzlLoadValue computeInternal( | 
|  | BzlLoadValue.Key key, Environment env, @Nullable InliningState inliningState) | 
|  | throws BzlLoadFailedException, InterruptedException { | 
|  | Label label = key.getLabel(); | 
|  | PathFragment filePath = label.toPathFragment(); | 
|  |  | 
|  | StarlarkBuiltinsValue builtins = getBuiltins(key, env, inliningState); | 
|  | if (builtins == null) { | 
|  | return null; | 
|  | } | 
|  |  | 
|  | BzlCompileValue.Key compileKey = | 
|  | validatePackageAndGetCompileKey( | 
|  | key, | 
|  | env, | 
|  | builtins.starlarkSemantics.get(BuildLanguageOptions.EXPERIMENTAL_BUILTINS_BZL_PATH)); | 
|  | if (compileKey == null) { | 
|  | return null; | 
|  | } | 
|  | BzlCompileValue compileValue; | 
|  | try { | 
|  | compileValue = getter.getBzlCompileValue(compileKey, env); | 
|  | } catch (BzlCompileFunction.FailedIOException e) { | 
|  | throw BzlLoadFailedException.errorReadingBzl(filePath, e); | 
|  | } | 
|  | if (compileValue == null) { | 
|  | return null; | 
|  | } | 
|  |  | 
|  | BzlLoadValue result = null; | 
|  | // Release the compiled bzl iff the value gets completely evaluated (to either error or non-null | 
|  | // result). | 
|  | boolean completed = true; | 
|  | try { | 
|  | result = computeInternalWithCompiledBzl(key, compileValue, builtins, env, inliningState); | 
|  | completed = result != null; | 
|  | } finally { | 
|  | if (completed) { // only false on unexceptional null result | 
|  | getter.doneWithBzlCompileValue(compileKey); | 
|  | } | 
|  | } | 
|  | return result; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Obtain a suitable StarlarkBuiltinsValue. | 
|  | * | 
|  | * <p>For BUILD-loaded .bzl files, this is a real builtins value, obtained using either Skyframe | 
|  | * or inlining of StarlarkBuiltinsFunction (depending on whether {@code inliningState} is | 
|  | * non-null). The returned value includes the StarlarkSemantics. | 
|  | * | 
|  | * <p>For other .bzl files, the builtins computation is not needed and would create a Skyframe | 
|  | * cycle if requested, so we instead return an empty builtins value that just wraps the | 
|  | * StarlarkSemantics. (NB: In the case of WORKSPACE-loaded .bzl files, the cycle goes through the | 
|  | * repository remapping value. It's possible this could be avoided if we ever wanted to make this | 
|  | * kind of .bzl file use builtins injection.) | 
|  | */ | 
|  | @Nullable | 
|  | private StarlarkBuiltinsValue getBuiltins( | 
|  | BzlLoadValue.Key key, Environment env, @Nullable InliningState inliningState) | 
|  | throws BzlLoadFailedException, InterruptedException { | 
|  | if (!(key instanceof BzlLoadValue.KeyForBuild)) { | 
|  | StarlarkSemantics starlarkSemantics = PrecomputedValue.STARLARK_SEMANTICS.get(env); | 
|  | if (starlarkSemantics == null) { | 
|  | return null; | 
|  | } | 
|  | return StarlarkBuiltinsValue.createEmpty(starlarkSemantics); | 
|  | } | 
|  | try { | 
|  | if (inliningState == null) { | 
|  | return (StarlarkBuiltinsValue) | 
|  | env.getValueOrThrow(StarlarkBuiltinsValue.key(), BuiltinsFailedException.class); | 
|  | } else { | 
|  | return StarlarkBuiltinsFunction.computeInline( | 
|  | StarlarkBuiltinsValue.key(), inliningState, packageFactory, /*bzlLoadFunction=*/ this); | 
|  | } | 
|  | } catch (BuiltinsFailedException e) { | 
|  | throw BzlLoadFailedException.builtinsFailed(key.getLabel(), e); | 
|  | } | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Given a bzl key, validates that the corresponding package exists (if required) and returns the | 
|  | * associated compile key based on the package's root. Returns null for a missing Skyframe dep or | 
|  | * unspecified exception. | 
|  | * | 
|  | * <p>.bzl files are not necessarily targets, because they can be loaded by BUILD and other .bzl | 
|  | * files without ever being declared in a BUILD file. However, .bzl files are still identified by | 
|  | * a label in the same way that file targets are. In particular, it is illegal to refer to a .bzl | 
|  | * file using a label whose package part is not the .bzl file's innermost containing package. For | 
|  | * example, if pkg and pkg/subpkg have BUILD files but not pkg/subdir, then {@code | 
|  | * pkg/subdir:foo.bzl} and {@code pkg:subpkg/foo.bzl} are disallowed. | 
|  | * | 
|  | * <p>In the case of builtins .bzl files, all labels are written as if the pseudo-repo constitutes | 
|  | * one big package, e.g {@code @builtins//:some/path/foo.bzl}, but no BUILD file need exist. The | 
|  | * compile key's root is determined by {@code --experimental_builtins_bzl_path} (passed as {@code | 
|  | * builtinsBzlPath}) instead of by package lookup. | 
|  | */ | 
|  | @Nullable | 
|  | private BzlCompileValue.Key validatePackageAndGetCompileKey( | 
|  | BzlLoadValue.Key key, Environment env, String builtinsBzlPath) | 
|  | throws BzlLoadFailedException, InterruptedException { | 
|  | Label label = key.getLabel(); | 
|  |  | 
|  | // Bypass package lookup entirely if builtins. | 
|  | if (key.isBuiltins()) { | 
|  | if (!label.getPackageName().isEmpty()) { | 
|  | throw BzlLoadFailedException.noBuildFile(label, "@_builtins cannot have subpackages"); | 
|  | } | 
|  | return key.getCompileKey(getBuiltinsRoot(builtinsBzlPath)); | 
|  | } | 
|  |  | 
|  | // Do package lookup. | 
|  | PathFragment dir = Label.getContainingDirectory(label); | 
|  | PackageIdentifier dirId = PackageIdentifier.create(label.getRepository(), dir); | 
|  | ContainingPackageLookupValue packageLookup; | 
|  | try { | 
|  | packageLookup = | 
|  | (ContainingPackageLookupValue) | 
|  | env.getValueOrThrow( | 
|  | ContainingPackageLookupValue.key(dirId), | 
|  | BuildFileNotFoundException.class, | 
|  | InconsistentFilesystemException.class); | 
|  | } catch (BuildFileNotFoundException | InconsistentFilesystemException e) { | 
|  | throw BzlLoadFailedException.errorFindingContainingPackage(label.toPathFragment(), e); | 
|  | } | 
|  | if (packageLookup == null) { | 
|  | return null; | 
|  | } | 
|  |  | 
|  | // Resolve to compile key or error. | 
|  | BzlCompileValue.Key compileKey; | 
|  | boolean packageOk = | 
|  | packageLookup.hasContainingPackage() | 
|  | && packageLookup.getContainingPackageName().equals(label.getPackageIdentifier()); | 
|  | if (key.isBuildPrelude() && !packageOk) { | 
|  | // Ignore the prelude, its package doesn't exist. | 
|  | compileKey = BzlCompileValue.EMPTY_PRELUDE_KEY; | 
|  | } else { | 
|  | if (packageOk) { | 
|  | compileKey = key.getCompileKey(packageLookup.getContainingPackageRoot()); | 
|  | } else { | 
|  | if (!packageLookup.hasContainingPackage()) { | 
|  | throw BzlLoadFailedException.noBuildFile( | 
|  | label, packageLookup.getReasonForNoContainingPackage()); | 
|  | } else { | 
|  | throw BzlLoadFailedException.labelCrossesPackageBoundary(label, packageLookup); | 
|  | } | 
|  | } | 
|  | } | 
|  | return compileKey; | 
|  | } | 
|  |  | 
|  | private Root getBuiltinsRoot(String builtinsBzlPath) { | 
|  | // TODO(#11437): Remove once injection can't be disabled. | 
|  | if (builtinsBzlPath.isEmpty()) { | 
|  | throw new IllegalStateException("Requested builtins root, but injection is disabled"); | 
|  | } | 
|  |  | 
|  | // TODO(#11437): For the non-bundled case, should we consider interning the Root rather than | 
|  | // constructing a new one each time? | 
|  | Root root; | 
|  | if (builtinsBzlPath.equals("%bundled%")) { | 
|  | // May be null in tests, but in that case the builtins path shouldn't be set to %bundled%. | 
|  | root = | 
|  | Preconditions.checkNotNull( | 
|  | packageFactory.getRuleClassProvider().getBundledBuiltinsRoot(), | 
|  | "rule class provider does not specify a builtins root; either call" | 
|  | + " setBuiltinsBzlZipResource() or else set --experimental_builtins_bzl_path to" | 
|  | + " a root"); | 
|  | } else if (builtinsBzlPath.equals("%workspace%")) { | 
|  | String packagePath = | 
|  | Preconditions.checkNotNull( | 
|  | packageFactory.getRuleClassProvider().getBuiltinsBzlPackagePathInSource(), | 
|  | "rule class provider does not specify a canonical package path to a builtins root;" | 
|  | + " either call setBuiltinsBzlPackagePathInSource() or else do not set" | 
|  | + "--experimental_builtins_bzl_path to %workspace%"); | 
|  | // TODO(brandjon): Here we return a root that is underneath a package root. Since the root is | 
|  | // itself not a package root, we don't get the benefit of any special DiffAwareness handling. | 
|  | // This case probably isn't important since it doesn't occur in production Bazel, but | 
|  | // presumably we might be able to add a special DiffAwareness for it if we wanted. | 
|  | root = Root.fromPath(directories.getWorkspace().getRelative(packagePath)); | 
|  | } else { | 
|  | root = Root.fromPath(directories.getWorkspace().getRelative(builtinsBzlPath)); | 
|  | } | 
|  | return root; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Compute logic for once the compiled .bzl has been fetched and confirmed to exist (though it may | 
|  | * have Starlark errors). | 
|  | */ | 
|  | @Nullable | 
|  | private BzlLoadValue computeInternalWithCompiledBzl( | 
|  | BzlLoadValue.Key key, | 
|  | BzlCompileValue compileValue, | 
|  | StarlarkBuiltinsValue builtins, | 
|  | Environment env, | 
|  | @Nullable InliningState inliningState) | 
|  | throws BzlLoadFailedException, InterruptedException { | 
|  | // Ensure the .bzl exists and passes static checks (parsing, resolving). | 
|  | // (A missing prelude file still returns a valid but empty BzlCompileValue.) | 
|  | if (!compileValue.lookupSuccessful()) { | 
|  | throw new BzlLoadFailedException(compileValue.getError(), Code.COMPILE_ERROR); | 
|  | } | 
|  | Program prog = compileValue.getProgram(); | 
|  |  | 
|  | // Determine dependency BzlLoadValue keys for the load statements in this bzl. | 
|  | // Labels are resolved relative to the current repo mapping. | 
|  | ImmutableMap<RepositoryName, RepositoryName> repoMapping = getRepositoryMapping(key, env); | 
|  | if (repoMapping == null) { | 
|  | return null; | 
|  | } | 
|  | ImmutableList<Pair<String, Location>> programLoads = getLoadsFromProgram(prog); | 
|  | ImmutableList<Label> loadLabels = | 
|  | getLoadLabels( | 
|  | env.getListener(), programLoads, key.getLabel().getPackageIdentifier(), repoMapping); | 
|  | if (loadLabels == null) { | 
|  | throw new BzlLoadFailedException( | 
|  | String.format( | 
|  | "module '%s'%s has invalid load statements", | 
|  | key.getLabel().toPathFragment(), | 
|  | StarlarkBuiltinsValue.isBuiltinsRepo(key.getLabel().getRepository()) | 
|  | ? " (internal)" | 
|  | : ""), | 
|  | Code.PARSE_ERROR); | 
|  | } | 
|  | ImmutableList.Builder<BzlLoadValue.Key> loadKeys = | 
|  | ImmutableList.builderWithExpectedSize(loadLabels.size()); | 
|  | for (Label loadLabel : loadLabels) { | 
|  | loadKeys.add(key.getKeyForLoad(loadLabel)); | 
|  | } | 
|  |  | 
|  | // Load .bzl modules. | 
|  | // When not using bzl inlining, this is done in parallel for all loads. | 
|  | List<BzlLoadValue> loadValues = | 
|  | inliningState == null | 
|  | ? computeBzlLoadsWithSkyframe(env, loadKeys.build(), programLoads) | 
|  | : computeBzlLoadsWithInlining(env, loadKeys.build(), programLoads, inliningState); | 
|  | if (loadValues == null) { | 
|  | return null; // Skyframe deps unavailable | 
|  | } | 
|  |  | 
|  | // Accumulate a transitive digest of the bzl file, the digests of its direct loads, and the | 
|  | // digest of the @_builtins pseudo-repository (if applicable). | 
|  | Fingerprint fp = new Fingerprint(); | 
|  | fp.addBytes(compileValue.getDigest()); | 
|  |  | 
|  | // Populate the load map and add transitive digests to the fingerprint. | 
|  | Map<String, Module> loadMap = Maps.newLinkedHashMapWithExpectedSize(programLoads.size()); | 
|  | int i = 0; | 
|  | for (Pair<String, Location> load : programLoads) { | 
|  | BzlLoadValue v = loadValues.get(i++); | 
|  | loadMap.put(load.first, v.getModule()); // dups ok | 
|  | fp.addBytes(v.getTransitiveDigest()); | 
|  | } | 
|  |  | 
|  | // Retrieve predeclared symbols and complete the digest computation. | 
|  | ImmutableMap<String, Object> predeclared = | 
|  | getAndDigestPredeclaredEnvironment(key, builtins, fp); | 
|  | if (predeclared == null) { | 
|  | return null; | 
|  | } | 
|  | byte[] transitiveDigest = fp.digestAndReset(); | 
|  |  | 
|  | // Construct the initial Starlark module, then execute the code and return the result. | 
|  | // The additional information in BazelModuleContext reifies the load DAG. | 
|  | // The module must match the environment used to compile the .bzl file. | 
|  | Module module = Module.withPredeclared(builtins.starlarkSemantics, predeclared); | 
|  | module.setClientData( | 
|  | BazelModuleContext.create( | 
|  | key.getLabel(), prog.getFilename(), ImmutableMap.copyOf(loadMap), transitiveDigest)); | 
|  |  | 
|  | // executeBzlFile may post events to the Environment's handler, but events do not matter when | 
|  | // caching BzlLoadValues. Note that executing the code mutates the module. | 
|  | executeBzlFile( | 
|  | prog, | 
|  | key.getLabel(), | 
|  | module, | 
|  | loadMap, | 
|  | builtins.starlarkSemantics, | 
|  | env.getListener(), | 
|  | repoMapping); | 
|  | return new BzlLoadValue(module, transitiveDigest); | 
|  | } | 
|  |  | 
|  | private static ImmutableMap<RepositoryName, RepositoryName> getRepositoryMapping( | 
|  | BzlLoadValue.Key key, Environment env) throws InterruptedException { | 
|  | if (key.isBuiltins()) { | 
|  | // Builtins .bzls never have a repo mapping defined for them, so return without requesting a | 
|  | // RepositoryMappingValue. (NB: In addition to being a slight optimization, this avoids | 
|  | // adding a reverse dependency on the special //external package, which helps avoid tickling | 
|  | // some peculiarities of the Google-internal Skyframe implementation; see b/182293526 for | 
|  | // details.) | 
|  | return ImmutableMap.of(); | 
|  | } | 
|  |  | 
|  | Label enclosingFileLabel = key.getLabel(); | 
|  |  | 
|  | ImmutableMap<RepositoryName, RepositoryName> repositoryMapping; | 
|  | if (key instanceof BzlLoadValue.KeyForWorkspace) { | 
|  | // Still during workspace file evaluation | 
|  | BzlLoadValue.KeyForWorkspace keyForWorkspace = (BzlLoadValue.KeyForWorkspace) key; | 
|  | if (keyForWorkspace.getWorkspaceChunk() == 0) { | 
|  | // There is no previous workspace chunk | 
|  | repositoryMapping = ImmutableMap.of(); | 
|  | } else { | 
|  | SkyKey workspaceFileKey = | 
|  | WorkspaceFileValue.key( | 
|  | keyForWorkspace.getWorkspacePath(), keyForWorkspace.getWorkspaceChunk() - 1); | 
|  | WorkspaceFileValue workspaceFileValue = (WorkspaceFileValue) env.getValue(workspaceFileKey); | 
|  | // Note: we know for sure that the requested WorkspaceFileValue is fully computed so we do | 
|  | // not need to check if it is null | 
|  | repositoryMapping = | 
|  | workspaceFileValue | 
|  | .getRepositoryMapping() | 
|  | .getOrDefault(enclosingFileLabel.getRepository(), ImmutableMap.of()); | 
|  | } | 
|  | } else if (key instanceof BzlLoadValue.KeyForBzlmod) { | 
|  | // TODO(pcloudy): Implement repo mapping for bzlmod repos | 
|  | return ImmutableMap.of(); | 
|  | } else { | 
|  | // We are fully done with workspace evaluation so we should get the mappings from the | 
|  | // final RepositoryMappingValue | 
|  | PackageIdentifier packageIdentifier = enclosingFileLabel.getPackageIdentifier(); | 
|  | RepositoryMappingValue repositoryMappingValue = | 
|  | (RepositoryMappingValue) | 
|  | env.getValue(RepositoryMappingValue.key(packageIdentifier.getRepository())); | 
|  | if (repositoryMappingValue == null) { | 
|  | return null; | 
|  | } | 
|  | repositoryMapping = repositoryMappingValue.getRepositoryMapping(); | 
|  | } | 
|  | return repositoryMapping; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Given a list of {@code load("module")} strings and their locations, in source order, returns a | 
|  | * corresponding list of Labels they each resolve to. Labels are resolved relative to {@code | 
|  | * base}, the file's package. If any label is malformed, the function reports one or more errors | 
|  | * to the handler and returns null. | 
|  | */ | 
|  | @Nullable | 
|  | static ImmutableList<Label> getLoadLabels( | 
|  | EventHandler handler, | 
|  | ImmutableList<Pair<String, Location>> loads, | 
|  | PackageIdentifier base, | 
|  | ImmutableMap<RepositoryName, RepositoryName> repoMapping) { | 
|  | Preconditions.checkArgument(!base.getRepository().isDefault()); | 
|  |  | 
|  | // It's redundant that getRelativeWithRemapping needs a Label; | 
|  | // a PackageIdentifier should suffice. Make one here. | 
|  | Label buildLabel = getBUILDLabel(base); | 
|  |  | 
|  | boolean ok = true; | 
|  |  | 
|  | ImmutableList.Builder<Label> loadLabels = ImmutableList.builderWithExpectedSize(loads.size()); | 
|  | for (Pair<String, Location> load : loads) { | 
|  | // Parse the load statement's module string as a label. | 
|  | // It must end in .bzl and not be in package "//external". | 
|  | try { | 
|  | Label label = buildLabel.getRelativeWithRemapping(load.first, repoMapping); | 
|  | if (!label.getName().endsWith(".bzl")) { | 
|  | throw new LabelSyntaxException("The label must reference a file with extension '.bzl'"); | 
|  | } | 
|  | if (label.getPackageIdentifier().equals(LabelConstants.EXTERNAL_PACKAGE_IDENTIFIER)) { | 
|  | throw new LabelSyntaxException( | 
|  | "Starlark files may not be loaded from the //external package"); | 
|  | } | 
|  | if (StarlarkBuiltinsValue.isBuiltinsRepo(base.getRepository()) | 
|  | && !StarlarkBuiltinsValue.isBuiltinsRepo(label.getRepository())) { | 
|  | throw new LabelSyntaxException( | 
|  | ".bzl files in @_builtins cannot load from outside of @_builtins"); | 
|  | } | 
|  | loadLabels.add(label); | 
|  | } catch (LabelSyntaxException ex) { | 
|  | handler.handle(Event.error(load.second, "in load statement: " + ex.getMessage())); | 
|  | ok = false; | 
|  | } | 
|  | } | 
|  | return ok ? loadLabels.build() : null; | 
|  | } | 
|  |  | 
|  | /** Extracts load statements from compiled program (see {@link #getLoadLabels}). */ | 
|  | static ImmutableList<Pair<String, Location>> getLoadsFromProgram(Program prog) { | 
|  | int n = prog.getLoads().size(); | 
|  | ImmutableList.Builder<Pair<String, Location>> loads = ImmutableList.builderWithExpectedSize(n); | 
|  | for (int i = 0; i < n; i++) { | 
|  | loads.add(Pair.of(prog.getLoads().get(i), prog.getLoadLocation(i))); | 
|  | } | 
|  | return loads.build(); | 
|  | } | 
|  |  | 
|  | /** Extracts load statements from file syntax (see {@link #getLoadLabels}). */ | 
|  | static ImmutableList<Pair<String, Location>> getLoadsFromStarlarkFiles(List<StarlarkFile> files) { | 
|  | ImmutableList.Builder<Pair<String, Location>> loads = ImmutableList.builder(); | 
|  | for (StarlarkFile file : files) { | 
|  | for (Statement stmt : file.getStatements()) { | 
|  | if (stmt instanceof LoadStatement) { | 
|  | StringLiteral module = ((LoadStatement) stmt).getImport(); | 
|  | loads.add(Pair.of(module.getValue(), module.getStartLocation())); | 
|  | } | 
|  | } | 
|  | } | 
|  | return loads.build(); | 
|  | } | 
|  |  | 
|  | private static Label getBUILDLabel(PackageIdentifier pkgid) { | 
|  | try { | 
|  | return Label.create(pkgid, "BUILD"); | 
|  | } catch (LabelSyntaxException e) { | 
|  | // Shouldn't happen; the Label is well-formed by construction. | 
|  | throw new IllegalStateException(e); | 
|  | } | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Computes the BzlLoadValue for all given .bzl load keys using ordinary Skyframe evaluation, | 
|  | * returning {@code null} if Skyframe deps were missing and have been requested. {@code | 
|  | * programLoads} provides the locations of the load statements in source order, for error | 
|  | * reporting. | 
|  | */ | 
|  | @Nullable | 
|  | private static List<BzlLoadValue> computeBzlLoadsWithSkyframe( | 
|  | Environment env, List<BzlLoadValue.Key> keys, List<Pair<String, Location>> programLoads) | 
|  | throws BzlLoadFailedException, InterruptedException { | 
|  | List<BzlLoadValue> bzlLoads = Lists.newArrayListWithExpectedSize(keys.size()); | 
|  | Map<SkyKey, ValueOrException<BzlLoadFailedException>> values = | 
|  | env.getValuesOrThrow(keys, BzlLoadFailedException.class); | 
|  | // Process loads (and report first error) in source order. | 
|  | for (int i = 0; i < keys.size(); i++) { | 
|  | try { | 
|  | bzlLoads.add((BzlLoadValue) values.get(keys.get(i)).get()); | 
|  | } catch (BzlLoadFailedException ex) { | 
|  | throw BzlLoadFailedException.whileLoadingDep(programLoads.get(i).second, ex); | 
|  | } | 
|  | } | 
|  | return env.valuesMissing() ? null : bzlLoads; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Computes the BzlLoadValue for all given keys by reusing this instance of the BzlLoadFunction, | 
|  | * bypassing traditional Skyframe evaluation. {@code programLoads} provides the locations of the | 
|  | * load statements in source order, for error reporting. | 
|  | * | 
|  | * @return null if there was a missing Skyframe dep, an unspecified exception in a Skyframe dep | 
|  | *     request, or if this was a duplicate unsuccessful visitation | 
|  | */ | 
|  | @Nullable | 
|  | private List<BzlLoadValue> computeBzlLoadsWithInlining( | 
|  | Environment env, | 
|  | List<BzlLoadValue.Key> keys, | 
|  | List<Pair<String, Location>> programLoads, | 
|  | InliningState inliningState) | 
|  | throws BzlLoadFailedException, InterruptedException { | 
|  | Preconditions.checkState(env == inliningState.recordingEnv); | 
|  |  | 
|  | List<BzlLoadValue> bzlLoads = Lists.newArrayListWithExpectedSize(keys.size()); | 
|  | // For the sake of ensuring the graph structure is deterministic, we need to request all of our | 
|  | // deps, even if some of them yield errors. The first exception that is seen gets deferred, to | 
|  | // be raised after the loop. All other exceptions are swallowed. | 
|  | // | 
|  | // To see how immediately returning the first error leads to non-determinism, consider the case | 
|  | // of two dependencies A and B, where A is in error and appears in a load statement above B. | 
|  | // If A has completed at the time we request it, and if we were to immediately propagate that | 
|  | // error, we never request B. On the other hand, if A is missing (null return), we do request B | 
|  | // in the meantime for the sake of parallelism. | 
|  | // | 
|  | // This approach assumes --keep_going; determinism is not guaranteed otherwise. It also assumes | 
|  | // InterruptedException does not occur, since we don't catch and defer it. | 
|  | BzlLoadFailedException deferredException = null; | 
|  | boolean valuesMissing = false; | 
|  | for (int i = 0; i < keys.size(); i++) { | 
|  | CachedBzlLoadData cachedData; | 
|  | try { | 
|  | cachedData = computeInlineCachedData(keys.get(i), inliningState); | 
|  | } catch (BzlLoadFailedException e) { | 
|  | if (deferredException == null) { | 
|  | deferredException = BzlLoadFailedException.whileLoadingDep(programLoads.get(i).second, e); | 
|  | } | 
|  | continue; | 
|  | } | 
|  | if (cachedData == null) { | 
|  | // A null value for `cachedData` can occur when it (or its transitive loads) has a Skyframe | 
|  | // dep that is missing or in error. It can also occur if there's a transitive load on a bzl | 
|  | // that was already seen by inliningState and which returned null (note: in this case, it's | 
|  | // not necessarily true that there are missing Skyframe deps because this bzl could have | 
|  | // already been visited unsuccessfully). In both these cases, we want to continue making our | 
|  | // inline calls, so as to maximize the number of dependent (non-inlined) SkyFunctions that | 
|  | // are requested and avoid a quadratic number of restarts. | 
|  | valuesMissing = true; | 
|  | } else { | 
|  | bzlLoads.add(cachedData.getValue()); | 
|  | } | 
|  | } | 
|  | if (deferredException != null) { | 
|  | throw deferredException; | 
|  | } | 
|  | return valuesMissing ? null : bzlLoads; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Obtains the predeclared environment for a .bzl file, based on the type of .bzl and (if | 
|  | * applicable) the injected builtins. | 
|  | * | 
|  | * <p>Returns null if there was a missing Skyframe dep or unspecified exception. | 
|  | * | 
|  | * <p>In the case that injected builtins are used, updates the given fingerprint with the digest | 
|  | * of the {@code @_builtins} pseudo-repository. | 
|  | */ | 
|  | @Nullable | 
|  | private ImmutableMap<String, Object> getAndDigestPredeclaredEnvironment( | 
|  | BzlLoadValue.Key key, StarlarkBuiltinsValue builtins, Fingerprint fp) | 
|  | throws BzlLoadFailedException, InterruptedException { | 
|  | BazelStarlarkEnvironment starlarkEnv = packageFactory.getBazelStarlarkEnvironment(); | 
|  | if (key instanceof BzlLoadValue.KeyForBuild) { | 
|  | // TODO(#11437): Remove ability to disable injection by setting flag to empty string. | 
|  | if (builtins | 
|  | .starlarkSemantics | 
|  | .get(BuildLanguageOptions.EXPERIMENTAL_BUILTINS_BZL_PATH) | 
|  | .isEmpty()) { | 
|  | return starlarkEnv.getUninjectedBuildBzlEnv(); | 
|  | } | 
|  | fp.addBytes(builtins.transitiveDigest); | 
|  | return builtins.predeclaredForBuildBzl; | 
|  | } else if (key instanceof BzlLoadValue.KeyForWorkspace) { | 
|  | return starlarkEnv.getWorkspaceBzlEnv(); | 
|  | } else if (key instanceof BzlLoadValue.KeyForBzlmod) { | 
|  | return starlarkEnv.getBzlmodBzlEnv(); | 
|  | } else if (key instanceof BzlLoadValue.KeyForBuiltins) { | 
|  | return starlarkEnv.getBuiltinsBzlEnv(); | 
|  | } else { | 
|  | throw new AssertionError("Unknown key type: " + key.getClass()); | 
|  | } | 
|  | } | 
|  |  | 
|  | /** Executes the compiled .bzl file defining the module to be loaded. */ | 
|  | private void executeBzlFile( | 
|  | Program prog, | 
|  | Label label, | 
|  | Module module, | 
|  | Map<String, Module> loadedModules, | 
|  | StarlarkSemantics starlarkSemantics, | 
|  | ExtendedEventHandler skyframeEventHandler, | 
|  | ImmutableMap<RepositoryName, RepositoryName> repositoryMapping) | 
|  | throws BzlLoadFailedException, InterruptedException { | 
|  | try (Mutability mu = Mutability.create("loading", label)) { | 
|  | StarlarkThread thread = new StarlarkThread(mu, starlarkSemantics); | 
|  | thread.setLoader(loadedModules::get); | 
|  | StoredEventHandler starlarkEventHandler = new StoredEventHandler(); | 
|  | thread.setPrintHandler(Event.makeDebugPrintHandler(starlarkEventHandler)); | 
|  | packageFactory | 
|  | .getRuleClassProvider() | 
|  | .setStarlarkThreadContext(thread, label, repositoryMapping); | 
|  | execAndExport(prog, label, starlarkEventHandler, module, thread); | 
|  |  | 
|  | Event.replayEventsOn(skyframeEventHandler, starlarkEventHandler.getEvents()); | 
|  | for (Postable post : starlarkEventHandler.getPosts()) { | 
|  | skyframeEventHandler.post(post); | 
|  | } | 
|  | if (starlarkEventHandler.hasErrors()) { | 
|  | throw BzlLoadFailedException.executionFailed(label); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | // Precondition: thread has a valid transitiveDigest. | 
|  | // TODO(adonovan): executeBzlFile would make a better public API than this function. | 
|  | public static void execAndExport( | 
|  | Program prog, Label label, EventHandler handler, Module module, StarlarkThread thread) | 
|  | throws InterruptedException { | 
|  |  | 
|  | // Intercept execution after every assignment at top level | 
|  | // and "export" any newly assigned exportable globals. | 
|  | // TODO(adonovan): change the semantics; see b/65374671. | 
|  | thread.setPostAssignHook( | 
|  | (name, value) -> { | 
|  | if (value instanceof StarlarkExportable) { | 
|  | StarlarkExportable exp = (StarlarkExportable) value; | 
|  | if (!exp.isExported()) { | 
|  | exp.export(handler, label, name); | 
|  | } | 
|  | } | 
|  | }); | 
|  |  | 
|  | try { | 
|  | Starlark.execFileProgram(prog, module, thread); | 
|  | } catch (EvalException ex) { | 
|  | handler.handle(Event.error(null, ex.getMessageWithStack())); | 
|  | } | 
|  | } | 
|  |  | 
|  | @Override | 
|  | public String extractTag(SkyKey skyKey) { | 
|  | return null; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * A manager abstracting over the method for obtaining {@code BzlCompileValue}s. See comment in | 
|  | * {@link #create}. | 
|  | */ | 
|  | private interface ValueGetter { | 
|  | @Nullable | 
|  | BzlCompileValue getBzlCompileValue(BzlCompileValue.Key key, Environment env) | 
|  | throws BzlCompileFunction.FailedIOException, InterruptedException; | 
|  |  | 
|  | void doneWithBzlCompileValue(BzlCompileValue.Key key); | 
|  | } | 
|  |  | 
|  | /** A manager that obtains compiled .bzl files from Skyframe calls. */ | 
|  | private static class RegularSkyframeGetter implements ValueGetter { | 
|  | private static final RegularSkyframeGetter INSTANCE = new RegularSkyframeGetter(); | 
|  |  | 
|  | @Nullable | 
|  | @Override | 
|  | public BzlCompileValue getBzlCompileValue(BzlCompileValue.Key key, Environment env) | 
|  | throws BzlCompileFunction.FailedIOException, InterruptedException { | 
|  | return (BzlCompileValue) env.getValueOrThrow(key, BzlCompileFunction.FailedIOException.class); | 
|  | } | 
|  |  | 
|  | @Override | 
|  | public void doneWithBzlCompileValue(BzlCompileValue.Key key) {} | 
|  | } | 
|  |  | 
|  | /** | 
|  | * A manager that obtains compiled .bzls by inlining {@link BzlCompileFunction} (not to be | 
|  | * confused with inlining of {@code BzlLoadFunction}). Values are cached within the manager and | 
|  | * released explicitly by calling {@link #doneWithBzlCompileValue}. | 
|  | */ | 
|  | private static class InliningAndCachingGetter implements ValueGetter { | 
|  | private final PackageFactory packageFactory; | 
|  | private final HashFunction hashFunction; | 
|  | // We keep a cache of BzlCompileValues that have been computed but whose corresponding | 
|  | // BzlLoadValue has not yet completed. This avoids repeating the BzlCompileValue work in case | 
|  | // of Skyframe restarts. (If we weren't inlining, Skyframe would cache this for us.) | 
|  | private final Cache<BzlCompileValue.Key, BzlCompileValue> bzlCompileCache; | 
|  |  | 
|  | private InliningAndCachingGetter( | 
|  | PackageFactory packageFactory, | 
|  | HashFunction hashFunction, | 
|  | Cache<BzlCompileValue.Key, BzlCompileValue> bzlCompileCache) { | 
|  | this.packageFactory = packageFactory; | 
|  | this.hashFunction = hashFunction; | 
|  | this.bzlCompileCache = bzlCompileCache; | 
|  | } | 
|  |  | 
|  | @Nullable | 
|  | @Override | 
|  | public BzlCompileValue getBzlCompileValue(BzlCompileValue.Key key, Environment env) | 
|  | throws BzlCompileFunction.FailedIOException, InterruptedException { | 
|  | BzlCompileValue value = bzlCompileCache.getIfPresent(key); | 
|  | if (value == null) { | 
|  | value = BzlCompileFunction.computeInline(key, env, packageFactory, hashFunction); | 
|  | if (value != null) { | 
|  | bzlCompileCache.put(key, value); | 
|  | } | 
|  | } | 
|  | return value; | 
|  | } | 
|  |  | 
|  | @Override | 
|  | public void doneWithBzlCompileValue(BzlCompileValue.Key key) { | 
|  | bzlCompileCache.invalidate(key); | 
|  | } | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Per-instance manager for {@link CachedBzlLoadData}, used when {@code BzlLoadFunction} calls are | 
|  | * inlined. | 
|  | */ | 
|  | private static class CachedBzlLoadDataManager { | 
|  | private final int cacheSize; | 
|  | private Cache<BzlLoadValue.Key, CachedBzlLoadData> cache; | 
|  | private CachedBzlLoadDataBuilderFactory cachedDataBuilderFactory = | 
|  | new CachedBzlLoadDataBuilderFactory(); | 
|  |  | 
|  | private CachedBzlLoadDataManager(int cacheSize) { | 
|  | this.cacheSize = cacheSize; | 
|  | } | 
|  |  | 
|  | private CachedBzlLoadData.Builder cachedDataBuilder() { | 
|  | return cachedDataBuilderFactory.newCachedBzlLoadDataBuilder(); | 
|  | } | 
|  |  | 
|  | private void reset() { | 
|  | if (cache != null) { | 
|  | logger.atInfo().log("Starlark inlining cache stats from earlier build: %s", cache.stats()); | 
|  | } | 
|  | cachedDataBuilderFactory = new CachedBzlLoadDataBuilderFactory(); | 
|  | Preconditions.checkState( | 
|  | cacheSize >= 0, "Expected positive Starlark cache size if caching. %s", cacheSize); | 
|  | cache = | 
|  | Caffeine.newBuilder() | 
|  | .initialCapacity(BlazeInterners.concurrencyLevel()) | 
|  | .maximumSize(cacheSize) | 
|  | .recordStats() | 
|  | .build(); | 
|  | } | 
|  | } | 
|  |  | 
|  | static final class BzlLoadFailedException extends Exception implements SaneAnalysisException { | 
|  | private final Transience transience; | 
|  | private final DetailedExitCode detailedExitCode; | 
|  |  | 
|  | private BzlLoadFailedException( | 
|  | String errorMessage, DetailedExitCode detailedExitCode, Transience transience) { | 
|  | super(errorMessage); | 
|  | this.transience = transience; | 
|  | this.detailedExitCode = detailedExitCode; | 
|  | } | 
|  |  | 
|  | private BzlLoadFailedException(String errorMessage, DetailedExitCode detailedExitCode) { | 
|  | this(errorMessage, detailedExitCode, Transience.PERSISTENT); | 
|  | } | 
|  |  | 
|  | private BzlLoadFailedException( | 
|  | String errorMessage, | 
|  | DetailedExitCode detailedExitCode, | 
|  | Exception cause, | 
|  | Transience transience) { | 
|  | super(errorMessage, cause); | 
|  | this.transience = transience; | 
|  | this.detailedExitCode = detailedExitCode; | 
|  | } | 
|  |  | 
|  | private BzlLoadFailedException(String errorMessage, Code code) { | 
|  | this(errorMessage, createDetailedExitCode(errorMessage, code), Transience.PERSISTENT); | 
|  | } | 
|  |  | 
|  | private BzlLoadFailedException( | 
|  | String errorMessage, Code code, Exception cause, Transience transience) { | 
|  | this(errorMessage, createDetailedExitCode(errorMessage, code), cause, transience); | 
|  | } | 
|  |  | 
|  | Transience getTransience() { | 
|  | return transience; | 
|  | } | 
|  |  | 
|  | @Override | 
|  | public DetailedExitCode getDetailedExitCode() { | 
|  | return detailedExitCode; | 
|  | } | 
|  |  | 
|  | private static DetailedExitCode createDetailedExitCode(String message, Code code) { | 
|  | return DetailedExitCode.of( | 
|  | FailureDetail.newBuilder() | 
|  | .setMessage(message) | 
|  | .setStarlarkLoading(StarlarkLoading.newBuilder().setCode(code)) | 
|  | .build()); | 
|  | } | 
|  |  | 
|  | private static BzlLoadFailedException whileLoadingDep( | 
|  | Location loc, BzlLoadFailedException cause) { | 
|  | // Don't chain exception cause, just incorporate the message with a prefix. | 
|  | // TODO(bazel-team): This exception should hold a Location of the requesting file's load | 
|  | // statement, and code that catches it should use the location in the Event they create. | 
|  | return new BzlLoadFailedException( | 
|  | "at " + loc + ": " + cause.getMessage(), cause.getDetailedExitCode()); | 
|  | } | 
|  |  | 
|  | static BzlLoadFailedException executionFailed(Label label) { | 
|  | return new BzlLoadFailedException( | 
|  | String.format( | 
|  | "initialization of module '%s'%s failed", | 
|  | label.toPathFragment(), | 
|  | StarlarkBuiltinsValue.isBuiltinsRepo(label.getRepository()) ? " (internal)" : ""), | 
|  | Code.EVAL_ERROR); | 
|  | } | 
|  |  | 
|  | static BzlLoadFailedException errorFindingContainingPackage( | 
|  | PathFragment file, Exception cause) { | 
|  | String errorMessage = | 
|  | String.format( | 
|  | "Encountered error while reading extension file '%s': %s", file, cause.getMessage()); | 
|  | DetailedExitCode detailedExitCode = | 
|  | cause instanceof DetailedException | 
|  | ? ((DetailedException) cause).getDetailedExitCode() | 
|  | : createDetailedExitCode(errorMessage, Code.CONTAINING_PACKAGE_NOT_FOUND); | 
|  | return new BzlLoadFailedException( | 
|  | errorMessage, detailedExitCode, cause, Transience.PERSISTENT); | 
|  | } | 
|  |  | 
|  | static BzlLoadFailedException errorReadingBzl( | 
|  | PathFragment file, BzlCompileFunction.FailedIOException cause) { | 
|  | String errorMessage = | 
|  | String.format( | 
|  | "Encountered error while reading extension file '%s': %s", file, cause.getMessage()); | 
|  | return new BzlLoadFailedException(errorMessage, Code.IO_ERROR, cause, cause.getTransience()); | 
|  | } | 
|  |  | 
|  | static BzlLoadFailedException noBuildFile(Label file, @Nullable String reason) { | 
|  | if (reason != null) { | 
|  | return new BzlLoadFailedException( | 
|  | String.format("Unable to find package for %s: %s.", file, reason), | 
|  | Code.PACKAGE_NOT_FOUND); | 
|  | } | 
|  | return new BzlLoadFailedException( | 
|  | String.format( | 
|  | "Every .bzl file must have a corresponding package, but '%s' does not have one." | 
|  | + " Please create a BUILD file in the same or any parent directory. Note that" | 
|  | + " this BUILD file does not need to do anything except exist.", | 
|  | file), | 
|  | Code.PACKAGE_NOT_FOUND); | 
|  | } | 
|  |  | 
|  | static BzlLoadFailedException labelCrossesPackageBoundary( | 
|  | Label label, ContainingPackageLookupValue containingPackageLookupValue) { | 
|  | return new BzlLoadFailedException( | 
|  | ContainingPackageLookupValue.getErrorMessageForLabelCrossingPackageBoundary( | 
|  | // We don't actually know the proper Root to pass in here (since we don't e.g. know | 
|  | // the root of the bzl/BUILD file that is trying to load 'label'). Therefore we just | 
|  | // pass in the Root of the containing package in order to still get a useful error | 
|  | // message for the user. | 
|  | containingPackageLookupValue.getContainingPackageRoot(), | 
|  | label, | 
|  | containingPackageLookupValue), | 
|  | Code.LABEL_CROSSES_PACKAGE_BOUNDARY); | 
|  | } | 
|  |  | 
|  | static BzlLoadFailedException builtinsFailed(Label file, BuiltinsFailedException cause) { | 
|  | return new BzlLoadFailedException( | 
|  | String.format( | 
|  | "Internal error while loading Starlark builtins for %s: %s", | 
|  | file, cause.getMessage()), | 
|  | Code.BUILTINS_ERROR, | 
|  | cause, | 
|  | cause.getTransience()); | 
|  | } | 
|  | } | 
|  |  | 
|  | private static final class BzlLoadFunctionException extends SkyFunctionException { | 
|  | private BzlLoadFunctionException(BzlLoadFailedException cause) { | 
|  | super(cause, cause.transience); | 
|  | } | 
|  | } | 
|  | } |