| // Copyright 2017 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 static java.util.stream.Collectors.joining; |
| |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.ImmutableMap; |
| import com.google.common.collect.ImmutableSet; |
| import com.google.devtools.build.lib.analysis.PlatformOptions; |
| import com.google.devtools.build.lib.analysis.config.BuildConfiguration; |
| import com.google.devtools.build.lib.analysis.platform.ConstraintCollection; |
| import com.google.devtools.build.lib.analysis.platform.ConstraintSettingInfo; |
| import com.google.devtools.build.lib.analysis.platform.ConstraintValueInfo; |
| import com.google.devtools.build.lib.analysis.platform.DeclaredToolchainInfo; |
| import com.google.devtools.build.lib.analysis.platform.PlatformInfo; |
| import com.google.devtools.build.lib.cmdline.Label; |
| import com.google.devtools.build.lib.events.Event; |
| import com.google.devtools.build.lib.events.EventHandler; |
| import com.google.devtools.build.lib.packages.NoSuchThingException; |
| import com.google.devtools.build.lib.skyframe.PlatformLookupUtil.InvalidPlatformException; |
| import com.google.devtools.build.lib.skyframe.RegisteredToolchainsFunction.InvalidToolchainLabelException; |
| import com.google.devtools.build.skyframe.SkyFunction; |
| import com.google.devtools.build.skyframe.SkyFunctionException; |
| import com.google.devtools.build.skyframe.SkyKey; |
| import com.google.devtools.build.skyframe.SkyValue; |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| import javax.annotation.Nullable; |
| |
| /** {@link SkyFunction} which performs toolchain resolution for a class of rules. */ |
| public class ToolchainResolutionFunction implements SkyFunction { |
| |
| @Nullable |
| @Override |
| public SkyValue compute(SkyKey skyKey, Environment env) |
| throws ToolchainResolutionFunctionException, InterruptedException { |
| ToolchainResolutionValue.Key key = (ToolchainResolutionValue.Key) skyKey.argument(); |
| |
| // This call could be combined with the call below, but this SkyFunction is evaluated so rarely |
| // it's not worth optimizing. |
| BuildConfigurationValue value = (BuildConfigurationValue) env.getValue(key.configurationKey()); |
| if (env.valuesMissing()) { |
| return null; |
| } |
| BuildConfiguration configuration = value.getConfiguration(); |
| |
| // Get all toolchains. |
| RegisteredToolchainsValue toolchains; |
| try { |
| toolchains = |
| (RegisteredToolchainsValue) |
| env.getValueOrThrow( |
| RegisteredToolchainsValue.key(key.configurationKey()), |
| InvalidToolchainLabelException.class); |
| if (toolchains == null) { |
| return null; |
| } |
| } catch (InvalidToolchainLabelException e) { |
| throw new ToolchainResolutionFunctionException(e); |
| } |
| |
| // Find the right one. |
| boolean debug = configuration.getOptions().get(PlatformOptions.class).toolchainResolutionDebug; |
| ImmutableMap<ConfiguredTargetKey, Label> resolvedToolchainLabels = |
| resolveConstraints( |
| key.toolchainType(), |
| key.availableExecutionPlatformKeys(), |
| key.targetPlatformKey(), |
| toolchains.registeredToolchains(), |
| env, |
| debug ? env.getListener() : null); |
| if (resolvedToolchainLabels == null) { |
| return null; |
| } |
| |
| if (resolvedToolchainLabels.isEmpty()) { |
| throw new ToolchainResolutionFunctionException( |
| new NoToolchainFoundException(key.toolchainType())); |
| } |
| |
| return ToolchainResolutionValue.create(resolvedToolchainLabels); |
| } |
| |
| /** |
| * Given the available execution platforms and toolchains, find the set of platform, toolchain |
| * pairs that are compatible a) with each other, and b) with the toolchain type and target |
| * platform. |
| */ |
| @Nullable |
| private static ImmutableMap<ConfiguredTargetKey, Label> resolveConstraints( |
| Label toolchainType, |
| List<ConfiguredTargetKey> availableExecutionPlatformKeys, |
| ConfiguredTargetKey targetPlatformKey, |
| ImmutableList<DeclaredToolchainInfo> toolchains, |
| Environment env, |
| @Nullable EventHandler eventHandler) |
| throws ToolchainResolutionFunctionException, InterruptedException { |
| |
| // Load the PlatformInfo needed to check constraints. |
| Map<ConfiguredTargetKey, PlatformInfo> platforms; |
| try { |
| |
| platforms = |
| PlatformLookupUtil.getPlatformInfo( |
| new ImmutableList.Builder<ConfiguredTargetKey>() |
| .add(targetPlatformKey) |
| .addAll(availableExecutionPlatformKeys) |
| .build(), |
| env); |
| if (env.valuesMissing()) { |
| return null; |
| } |
| } catch (InvalidPlatformException e) { |
| throw new ToolchainResolutionFunctionException(e); |
| } |
| |
| PlatformInfo targetPlatform = platforms.get(targetPlatformKey); |
| |
| // Platforms may exist multiple times in availableExecutionPlatformKeys. The Set lets this code |
| // check whether a platform has already been seen during processing. |
| Set<ConfiguredTargetKey> platformKeysSeen = new HashSet<>(); |
| ImmutableMap.Builder<ConfiguredTargetKey, Label> builder = ImmutableMap.builder(); |
| |
| debugMessage(eventHandler, "Looking for toolchain of type %s...", toolchainType); |
| for (DeclaredToolchainInfo toolchain : toolchains) { |
| // Make sure the type matches. |
| if (!toolchain.toolchainType().equals(toolchainType)) { |
| continue; |
| } |
| debugMessage(eventHandler, " Considering toolchain %s...", toolchain.toolchainLabel()); |
| |
| // Make sure the target platform matches. |
| if (!checkConstraints( |
| eventHandler, toolchain.targetConstraints(), "target", targetPlatform)) { |
| debugMessage( |
| eventHandler, |
| " Rejected toolchain %s, because of target platform mismatch", |
| toolchain.toolchainLabel()); |
| continue; |
| } |
| |
| // Find the matching execution platforms. |
| for (ConfiguredTargetKey executionPlatformKey : availableExecutionPlatformKeys) { |
| PlatformInfo executionPlatform = platforms.get(executionPlatformKey); |
| if (!checkConstraints( |
| eventHandler, toolchain.execConstraints(), "execution", executionPlatform)) { |
| continue; |
| } |
| |
| // Only add the toolchains if this is a new platform. |
| if (!platformKeysSeen.contains(executionPlatformKey)) { |
| builder.put(executionPlatformKey, toolchain.toolchainLabel()); |
| platformKeysSeen.add(executionPlatformKey); |
| } |
| } |
| } |
| |
| ImmutableMap<ConfiguredTargetKey, Label> resolvedToolchainLabels = builder.build(); |
| if (resolvedToolchainLabels.isEmpty()) { |
| debugMessage(eventHandler, " No toolchains found"); |
| } else { |
| debugMessage( |
| eventHandler, |
| " For toolchain type %s, possible execution platforms and toolchains: {%s}", |
| toolchainType, |
| resolvedToolchainLabels |
| .entrySet() |
| .stream() |
| .map(e -> String.format("%s -> %s", e.getKey().getLabel(), e.getValue())) |
| .collect(joining(", "))); |
| } |
| |
| return resolvedToolchainLabels; |
| } |
| |
| /** |
| * Helper method to print a debugging message, if the given {@link EventHandler} is not {@code |
| * null}. |
| */ |
| private static void debugMessage( |
| @Nullable EventHandler eventHandler, String template, Object... args) { |
| if (eventHandler == null) { |
| return; |
| } |
| |
| eventHandler.handle(Event.info("ToolchainResolution: " + String.format(template, args))); |
| } |
| |
| /** |
| * Returns {@code true} iff all constraints set by the toolchain and in the {@link PlatformInfo} |
| * match. |
| */ |
| private static boolean checkConstraints( |
| @Nullable EventHandler eventHandler, |
| ConstraintCollection toolchainConstraints, |
| String platformType, |
| PlatformInfo platform) { |
| |
| // Check every constraint_setting in either the toolchain or the platform. |
| ImmutableSet<ConstraintSettingInfo> constraints = |
| new ImmutableSet.Builder<ConstraintSettingInfo>() |
| .addAll(toolchainConstraints.constraintSettings()) |
| .addAll(platform.constraints().constraintSettings()) |
| .build(); |
| for (ConstraintSettingInfo constraintSetting : constraints) { |
| ConstraintValueInfo toolchainConstraint = toolchainConstraints.get(constraintSetting); |
| ConstraintValueInfo found = platform.constraints().get(constraintSetting); |
| |
| // Does the toolchain care about this constraint (possibly due to a default), and is it |
| // different? |
| if (toolchainConstraint != null && !toolchainConstraint.equals(found)) { |
| debugMessage( |
| eventHandler, |
| " Toolchain constraint %s has value %s, " |
| + "which does not match value %s from the %s platform %s", |
| constraintSetting.label(), |
| toolchainConstraint != null ? toolchainConstraint.label() : "<missing>", |
| found != null ? found.label() : "<missing>", |
| platformType, |
| platform.label()); |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| @Nullable |
| @Override |
| public String extractTag(SkyKey skyKey) { |
| return null; |
| } |
| |
| /** Used to indicate that a toolchain was not found for the current request. */ |
| public static final class NoToolchainFoundException extends NoSuchThingException { |
| private final Label missingToolchainType; |
| |
| public NoToolchainFoundException(Label missingToolchainType) { |
| super(String.format("no matching toolchain found for %s", missingToolchainType)); |
| this.missingToolchainType = missingToolchainType; |
| } |
| |
| public Label missingToolchainType() { |
| return missingToolchainType; |
| } |
| } |
| |
| /** Used to indicate errors during the computation of an {@link ToolchainResolutionValue}. */ |
| private static final class ToolchainResolutionFunctionException extends SkyFunctionException { |
| public ToolchainResolutionFunctionException(NoToolchainFoundException e) { |
| super(e, Transience.PERSISTENT); |
| } |
| |
| public ToolchainResolutionFunctionException(InvalidToolchainLabelException e) { |
| super(e, Transience.PERSISTENT); |
| } |
| |
| public ToolchainResolutionFunctionException(InvalidPlatformException e) { |
| super(e, Transience.PERSISTENT); |
| } |
| } |
| } |