com.google.gwt.dev.cfg.Rule Maven / Gradle / Ivy
/*
* Copyright 2006 Google 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.google.gwt.dev.cfg;
import com.google.gwt.core.ext.GeneratorContext;
import com.google.gwt.core.ext.RebindResult;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.UnableToCompleteException;
import com.google.gwt.dev.javac.StandardGeneratorContext;
/**
* Abstract base class for various kinds of deferred binding rules.
*/
public abstract class Rule {
protected RuntimeRebindRuleGenerator runtimeRebindRuleGenerator =
new RuntimeRebindRuleGenerator();
private int fallbackEvalCost = Integer.MAX_VALUE;
private final ConditionAll rootCondition = new ConditionAll();
/**
* Generate runtime rebind classes that perform the same rebinding behavior represented by the
* current Rule.
*/
@SuppressWarnings("unused")
public void generateRuntimeRebindClasses(
TreeLogger logger, ModuleDef module, GeneratorContext context)
throws UnableToCompleteException {
// Defaults to doing nothing.
}
/**
* Returns the cost of evaluation fallback binding values.
* when isApplicable() is true, this value is meaningless
* when isApplicable() is false, [1,Integer.MAX_VALUE-1] means
* a relative scale of cost, where cost c is better than cost c+k
* Integer.MAX_VALUE implies no match.
* @return cost of evaluating fallback values.
*/
public int getFallbackEvaluationCost() {
return fallbackEvalCost;
}
public ConditionAll getRootCondition() {
return rootCondition;
}
public boolean isApplicable(TreeLogger logger, StandardGeneratorContext context, String typeName)
throws UnableToCompleteException {
DeferredBindingQuery query = new DeferredBindingQuery(
context.getPropertyOracle(), context.getActiveLinkerNames(),
context.getCompilationState(), typeName);
boolean result = rootCondition.isTrue(logger, query);
fallbackEvalCost = query.getFallbackEvaluationCost();
return result;
}
public abstract RebindResult realize(TreeLogger logger,
StandardGeneratorContext context, String typeName)
throws UnableToCompleteException;
protected void dispose() {
}
/**
* Generate and return a String of Java source that will create an instance of whatever type this
* Rule intends to rebind to.
*/
protected abstract String generateCreateInstanceExpression();
/**
* Generate and return a String of Java source that will act as a condition to filter the runtime
* environment and only pass when the Rule's intended conditions are met.
*/
protected abstract String generateMatchesExpression();
}