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// 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.common.options;
import com.google.common.collect.ImmutableList;
import com.google.common.flogger.GoogleLogger;
import java.util.Objects;
/**
* The position of an option in the interpretation order. Options are interpreted using a
* last-option-wins system for single valued options, and are listed in that order for
* multiple-valued options.
*
* <p>The position of the option is in category order, and within the priority category in index
* order.
*/
public class OptionPriority implements Comparable<OptionPriority> {
private static final GoogleLogger logger = GoogleLogger.forEnclosingClass();
private final PriorityCategory priorityCategory;
/**
* Each option that is passed explicitly has 0 ancestors, so it only has its command line index
* (or rc index, etc., depending on the category), but expanded options have the command line
* index of its parent and then its position within the options that were expanded at that point.
* Since options can expand to expanding options, and --config can expand to expansion options as
* well, this can technically go arbitrarily deep, but in practice this is very short, of length <
* 5, most commonly of length 1.
*/
private final ImmutableList<Integer> priorityIndices;
private boolean alreadyExpanded = false;
private OptionPriority(
PriorityCategory priorityCategory, ImmutableList<Integer> priorityIndices) {
this.priorityCategory = priorityCategory;
this.priorityIndices = priorityIndices;
}
/** Get the first OptionPriority for that category. */
static OptionPriority lowestOptionPriorityAtCategory(PriorityCategory category) {
return new OptionPriority(category, ImmutableList.of(0));
}
/**
* Get the priority for the option following this one. In normal, incremental option parsing, the
* returned priority would compareTo as after the current one. Does not increment ancestor
* priorities.
*/
static OptionPriority nextOptionPriority(OptionPriority priority) {
int lastElementPosition = priority.priorityIndices.size() - 1;
return new OptionPriority(
priority.priorityCategory,
ImmutableList.<Integer>builder()
.addAll(priority.priorityIndices.subList(0, lastElementPosition))
.add(priority.priorityIndices.get(lastElementPosition) + 1)
.build());
}
/**
* Some options are expanded to other options, and the children options need to have their order
* preserved while maintaining their position between the options that flank the parent option.
*
* @return the priority for the first child of the passed priority. This child's ordering can be
* tracked the same way that the parent's was.
*/
public static OptionPriority getChildPriority(OptionPriority parentPriority)
throws OptionsParsingException {
if (parentPriority.alreadyExpanded) {
// TODO(bazel-team): Either tighten sanity check or prevent multiple
// expansions when implicit requirements are set.
logger.atWarning().log("Tried to expand option too many times.");
}
// Prevent this option from being re-expanded.
parentPriority.alreadyExpanded = true;
// The child priority has 1 more level of nesting than its parent.
return new OptionPriority(
parentPriority.priorityCategory,
ImmutableList.<Integer>builder().addAll(parentPriority.priorityIndices).add(0).build());
}
public PriorityCategory getPriorityCategory() {
return priorityCategory;
}
@Override
public int compareTo(OptionPriority o) {
if (priorityCategory.equals(o.priorityCategory)) {
for (int i = 0; i < priorityIndices.size() && i < o.priorityIndices.size(); ++i) {
if (!priorityIndices.get(i).equals(o.priorityIndices.get(i))) {
return priorityIndices.get(i).compareTo(o.priorityIndices.get(i));
}
}
// The values are up to the shorter one's length are the same, so the shorter one is a direct
// ancestor and comes first.
return Integer.compare(priorityIndices.size(), o.priorityIndices.size());
}
return Integer.compare(priorityCategory.ordinal(), o.priorityCategory.ordinal());
}
@Override
public boolean equals(Object o) {
if (o instanceof OptionPriority) {
OptionPriority other = (OptionPriority) o;
return priorityCategory.equals(other.priorityCategory)
&& priorityIndices.equals(other.priorityIndices);
}
return false;
}
@Override
public int hashCode() {
return Objects.hash(priorityCategory, priorityIndices);
}
@Override
public String toString() {
return String.format("OptionPriority(%s,%s)", priorityCategory, priorityIndices);
}
/**
* The priority of option values, in order of increasing priority.
*
* <p>In general, new values for options can only override values with a lower or equal priority.
* Option values provided in annotations in an options class are implicitly at the priority {@code
* DEFAULT}.
*
* <p>The ordering of the priorities is the source-code order. This is consistent with the
* automatically generated {@code compareTo} method as specified by the Java Language
* Specification. DO NOT change the source-code order of these values, or you will break code that
* relies on the ordering.
*/
public enum PriorityCategory {
/**
* The priority of values specified in the {@link Option} annotation. This should never be
* specified in calls to {@link OptionsParser#parse}.
*/
DEFAULT,
/**
* Overrides default options at runtime, while still allowing the values to be overridden
* manually.
*/
COMPUTED_DEFAULT,
/** For options coming from a configuration file or rc file. */
RC_FILE,
/** For options coming from the command line. */
COMMAND_LINE,
/** For options coming from invocation policy. */
INVOCATION_POLICY,
/**
* This priority can be used to unconditionally override any user-provided options. This should
* be used rarely and with caution!
*/
SOFTWARE_REQUIREMENT
}
}