com.facebook.buck.rules.macros.OutputMacroExpander.java Source code

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Here is the source code for com.facebook.buck.rules.macros.OutputMacroExpander.java

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/*
 * Copyright 2017-present Facebook, Inc.
 *
 * 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.facebook.buck.rules.macros;

import com.facebook.buck.core.cell.resolver.CellPathResolver;
import com.facebook.buck.core.exceptions.HumanReadableException;
import com.facebook.buck.core.model.BuildTarget;
import com.facebook.buck.core.rulekey.AddToRuleKey;
import com.facebook.buck.core.rules.ActionGraphBuilder;
import com.facebook.buck.core.rules.BuildRule;
import com.facebook.buck.core.rules.BuildRuleResolver;
import com.facebook.buck.core.rules.attr.HasSupplementaryOutputs;
import com.facebook.buck.core.sourcepath.SourcePath;
import com.facebook.buck.core.sourcepath.resolver.SourcePathResolver;
import com.facebook.buck.model.macros.MacroException;
import com.facebook.buck.rules.args.Arg;
import com.google.common.collect.ImmutableList;
import java.util.function.Consumer;

/** Handles '$(output ...)' macro which expands to the path of a named supplementary output. */
public class OutputMacroExpander extends AbstractMacroExpanderWithoutPrecomputedWork<OutputMacro> {
    @Override
    public Arg expandFrom(BuildTarget target, CellPathResolver cellNames, ActionGraphBuilder graphBuilder,
            OutputMacro input) {
        return new OutputArg(input, graphBuilder, target);
    }

    @Override
    public Class<OutputMacro> getInputClass() {
        return OutputMacro.class;
    }

    @Override
    protected OutputMacro parse(BuildTarget target, CellPathResolver cellNames, ImmutableList<String> args)
            throws MacroException {
        if (args.size() != 1) {
            throw new MacroException(String.format("expected exactly one argument (found %d)", args.size()));
        }
        return OutputMacro.of(args.get(0));
    }

    private static class OutputArg implements Arg {
        @AddToRuleKey
        private final String name;

        private final BuildRuleResolver resolver;
        private final BuildTarget target;

        public OutputArg(OutputMacro input, BuildRuleResolver resolver, BuildTarget target) {
            this.resolver = resolver;
            this.target = target;
            this.name = input.getOutputName();
        }

        @Override
        public void appendToCommandLine(Consumer<String> consumer, SourcePathResolver pathResolver) {
            // Ideally, we'd support some way to query the `HasSupplementalOutputs` interface via a
            // `SourcePathResolver` so we wouldn't need to capture the `BuildRuleResolver`.
            BuildRule rule = resolver.getRuleOptional(target).orElseThrow(
                    () -> new AssertionError("Expected build target to resolve to a build rule: " + target));
            if (rule instanceof HasSupplementaryOutputs) {
                SourcePath output = ((HasSupplementaryOutputs) rule).getSourcePathToSupplementaryOutput(name);
                if (output != null) {
                    // Note: As this is only used by the declaring rule, it can just use a relative path
                    // here as it will necessarily be expanded in the same cell.
                    consumer.accept(pathResolver.getRelativePath(output).toString());
                    return;
                }
            }
            throw new HumanReadableException(
                    String.format("%s: rule does not have an output with the name: %s", target, name));
        }
    }
}