com.google.devtools.build.lib.rules.platform.Platform.java Source code

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Here is the source code for com.google.devtools.build.lib.rules.platform.Platform.java

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// 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.rules.platform;

import com.google.common.collect.ArrayListMultimap;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterables;
import com.google.common.collect.Multimap;
import com.google.devtools.build.lib.analysis.ConfiguredTarget;
import com.google.devtools.build.lib.analysis.FileProvider;
import com.google.devtools.build.lib.analysis.FilesToRunProvider;
import com.google.devtools.build.lib.analysis.RuleConfiguredTarget.Mode;
import com.google.devtools.build.lib.analysis.RuleConfiguredTargetBuilder;
import com.google.devtools.build.lib.analysis.RuleContext;
import com.google.devtools.build.lib.analysis.RunfilesProvider;
import com.google.devtools.build.lib.rules.RuleConfiguredTargetFactory;
import com.google.devtools.build.lib.syntax.Type;
import java.util.Map;

/** Defines a platform for execution contexts. */
public class Platform implements RuleConfiguredTargetFactory {
    @Override
    public ConfiguredTarget create(RuleContext ruleContext) throws InterruptedException, RuleErrorException {

        Iterable<ConstraintValueInfo> constraintValues = ConstraintValueInfo
                .fromTargets(ruleContext.getPrerequisites(PlatformRule.CONSTRAINT_VALUES_ATTR, Mode.DONT_CHECK));

        // Verify the constraints - no two values for the same setting, and construct the map.
        ImmutableMap<ConstraintSettingInfo, ConstraintValueInfo> constraints = validateConstraints(ruleContext,
                constraintValues);
        if (constraints == null) {
            // An error occurred, return null.
            return null;
        }

        PlatformInfo.Builder platformProviderBuilder = PlatformInfo.builder();
        platformProviderBuilder.constraints(constraints.values());

        Map<String, String> remoteExecutionProperties = ruleContext.attributes()
                .get(PlatformRule.REMOTE_EXECUTION_PROPS_ATTR, Type.STRING_DICT);
        platformProviderBuilder.remoteExecutionProperties(remoteExecutionProperties);

        return new RuleConfiguredTargetBuilder(ruleContext)
                .addProvider(RunfilesProvider.class, RunfilesProvider.EMPTY)
                .addProvider(FileProvider.class, FileProvider.EMPTY)
                .addProvider(FilesToRunProvider.class, FilesToRunProvider.EMPTY)
                .addNativeDeclaredProvider(platformProviderBuilder.build()).build();
    }

    private ImmutableMap<ConstraintSettingInfo, ConstraintValueInfo> validateConstraints(RuleContext ruleContext,
            Iterable<ConstraintValueInfo> constraintValues) {
        Multimap<ConstraintSettingInfo, ConstraintValueInfo> constraints = ArrayListMultimap.create();

        for (ConstraintValueInfo constraintValue : constraintValues) {
            constraints.put(constraintValue.constraint(), constraintValue);
        }

        // Are there any settings with more than one value?
        boolean foundError = false;
        for (ConstraintSettingInfo constraintSetting : constraints.keySet()) {
            if (constraints.get(constraintSetting).size() > 1) {
                foundError = true;
                // error
                StringBuilder constraintValuesDescription = new StringBuilder();
                for (ConstraintValueInfo constraintValue : constraints.get(constraintSetting)) {
                    if (constraintValuesDescription.length() > 0) {
                        constraintValuesDescription.append(", ");
                    }
                    constraintValuesDescription.append(constraintValue.label());
                }
                ruleContext.attributeError(PlatformRule.CONSTRAINT_VALUES_ATTR,
                        String.format("Duplicate constraint_values for constraint_setting %s: %s",
                                constraintSetting.label(), constraintValuesDescription.toString()));
            }
        }

        if (foundError) {
            return null;
        }

        // Convert to a flat map.
        ImmutableMap.Builder<ConstraintSettingInfo, ConstraintValueInfo> builder = new ImmutableMap.Builder<>();
        for (ConstraintSettingInfo constraintSetting : constraints.keySet()) {
            ConstraintValueInfo constraintValue = Iterables.getOnlyElement(constraints.get(constraintSetting));
            builder.put(constraintSetting, constraintValue);
        }

        return builder.build();
    }
}