// 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.analysis.config;
import com.google.common.collect.ImmutableMap;
import com.google.devtools.common.options.Option;
import com.google.devtools.common.options.OptionsBase;
import com.google.devtools.common.options.OptionsParser.OptionUsageRestrictions;
import java.io.Serializable;
import java.lang.reflect.Field;
import java.util.Map;
import javax.annotation.Nullable;
/**
* Introspector for option details - what OptionsBase class the option is defined in, the option's
* current value, and whether the option allows multiple values to be specified.
*
* <p>This is "transitive" in that it includes *all* options recognizable by a given configuration,
* including those defined in child fragments.
*/
public final class TransitiveOptionDetails implements Serializable {
/**
* Computes and returns the transitive optionName -> "option info" map for the given set of
* options sets, using the given map as defaults for options which would otherwise be null.
*/
public static TransitiveOptionDetails forOptionsWithDefaults(
Iterable<? extends OptionsBase> buildOptions, Map<String, Object> lateBoundDefaults) {
ImmutableMap.Builder<String, OptionDetails> map = ImmutableMap.builder();
try {
for (OptionsBase options : buildOptions) {
for (Field field : options.getClass().getFields()) {
if (field.isAnnotationPresent(Option.class)) {
Option option = field.getAnnotation(Option.class);
if (option.optionUsageRestrictions() == OptionUsageRestrictions.INTERNAL) {
// ignore internal options
continue;
}
Object value = field.get(options);
if (value == null) {
if (lateBoundDefaults.containsKey(option.name())) {
value = lateBoundDefaults.get(option.name());
} else if (!option.defaultValue().equals("null")) {
// See {@link Option#defaultValue} for an explanation of default "null" strings.
value = option.defaultValue();
}
}
map.put(option.name(),
new OptionDetails(options.getClass(), value, option.allowMultiple()));
}
}
}
} catch (IllegalAccessException e) {
throw new IllegalStateException(
"Unexpected illegal access trying to create this configuration's options map: ", e);
}
return new TransitiveOptionDetails(map.build());
}
private static final class OptionDetails implements Serializable {
private OptionDetails(Class<? extends OptionsBase> optionsClass, Object value,
boolean allowsMultiple) {
this.optionsClass = optionsClass;
this.value = value;
this.allowsMultiple = allowsMultiple;
}
/** The {@link FragmentOptions} class that defines this option. */
private final Class<? extends OptionsBase> optionsClass;
/** The value of the given option (either explicitly defined or default). May be null. */
@Nullable private final Object value;
/** Whether or not this option supports multiple values. */
private final boolean allowsMultiple;
}
/**
* Maps option names to the {@link OptionDetails} the option takes for this configuration.
*
* <p>This can be used to:
*
* <ol>
* <li>Find an option's (parsed) value given its command-line name
* <li>Parse alternative values for the option.
* </ol>
*/
private final ImmutableMap<String, OptionDetails> transitiveOptionsMap;
private TransitiveOptionDetails(ImmutableMap<String, OptionDetails> transitiveOptionsMap) {
this.transitiveOptionsMap = transitiveOptionsMap;
}
/**
* Returns the {@link Option} class the defines the given option, null if the option isn't
* recognized.
*
* <p>optionName is the name of the option as it appears on the command line e.g. {@link
* Option#name}).
*/
public Class<? extends OptionsBase> getOptionClass(String optionName) {
OptionDetails optionData = transitiveOptionsMap.get(optionName);
return optionData == null ? null : optionData.optionsClass;
}
/**
* Returns the value of the specified option for this configuration or null if the option isn't
* recognized. Since an option's legitimate value could be null, use {@link #getOptionClass} to
* distinguish between that and an unknown option.
*
* <p>optionName is the name of the option as it appears on the command line e.g. {@link
* Option#name}).
*/
public Object getOptionValue(String optionName) {
OptionDetails optionData = transitiveOptionsMap.get(optionName);
return (optionData == null) ? null : optionData.value;
}
/**
* Returns whether or not the given option supports multiple values at the command line (e.g.
* "--myoption value1 --myOption value2 ..."). Returns false for unrecognized options. Use
* {@link #getOptionClass} to distinguish between those and legitimate single-value options.
*
* <p>As declared in {@link Option#allowMultiple}, multi-value options are expected to be
* of type {@code List<T>}.
*/
public boolean allowsMultipleValues(String optionName) {
OptionDetails optionData = transitiveOptionsMap.get(optionName);
return (optionData == null) ? false : optionData.allowsMultiple;
}
}