com.google.gwt.dev.jjs.impl.gflow.liveness.LivenessAnalysis Maven / Gradle / Ivy
/*
* Copyright 2008 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.jjs.impl.gflow.liveness;
import com.google.gwt.dev.jjs.impl.gflow.Analysis;
import com.google.gwt.dev.jjs.impl.gflow.AssumptionMap;
import com.google.gwt.dev.jjs.impl.gflow.FlowFunction;
import com.google.gwt.dev.jjs.impl.gflow.IntegratedAnalysis;
import com.google.gwt.dev.jjs.impl.gflow.IntegratedFlowFunction;
import com.google.gwt.dev.jjs.impl.gflow.cfg.Cfg;
import com.google.gwt.dev.jjs.impl.gflow.cfg.CfgEdge;
import com.google.gwt.dev.jjs.impl.gflow.cfg.CfgNode;
import com.google.gwt.dev.jjs.impl.gflow.cfg.CfgTransformer;
/**
* Analysis which detects when variable is not used after the assignment,
* and eliminates assignment.
*/
public class LivenessAnalysis implements Analysis, CfgEdge, Cfg,
LivenessAssumption>, IntegratedAnalysis, CfgEdge, CfgTransformer,
Cfg, LivenessAssumption> {
private static final LivenessFlowFunction FLOW_FUNCTION =
new LivenessFlowFunction();
private static final LivenessIntegratedFlowFunction INTEGRATED_FLOW_FUNCTION =
new LivenessIntegratedFlowFunction();
@Override
public FlowFunction, CfgEdge, Cfg, LivenessAssumption> getFlowFunction() {
return FLOW_FUNCTION;
}
@Override
public IntegratedFlowFunction, CfgEdge, CfgTransformer, Cfg,
LivenessAssumption>
getIntegratedFlowFunction() {
return INTEGRATED_FLOW_FUNCTION;
}
@Override
public void setInitialGraphAssumptions(Cfg graph,
AssumptionMap assumptionMap) {
// bottom assumptions.
}
}