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RoboVM fork of Soot - A Java optimization framework
/* Soot - a J*va Optimization Framework
* Copyright (C) 1997-1999 Raja Vallee-Rai
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/*
* Modified by the Sable Research Group and others 1997-1999.
* See the 'credits' file distributed with Soot for the complete list of
* contributors. (Soot is distributed at http://www.sable.mcgill.ca/soot)
*/
package soot.toolkits.scalar;
import java.util.HashMap;
import java.util.Map;
import soot.jimple.Stmt;
import soot.options.Options;
import soot.toolkits.graph.DirectedGraph;
import soot.toolkits.graph.interaction.InteractionHandler;
/** An abstract class providing a metaframework for carrying out
* dataflow analysis. This class provides common methods and fields
* required by the BranchedFlowAnalysis and FlowAnalysis abstract classes.
* @param node type of the directed graph
* @param abstraction type
*/
public abstract class AbstractFlowAnalysis
{
/** Maps graph nodes to IN sets. */
protected Map unitToBeforeFlow;
/** Filtered: Maps graph nodes to IN sets. */
protected Map filterUnitToBeforeFlow;
/** The graph being analysed. */
protected DirectedGraph graph;
/** Constructs a flow analysis on the given DirectedGraph. */
public AbstractFlowAnalysis(DirectedGraph graph)
{
unitToBeforeFlow = new HashMap(graph.size() * 2 + 1, 0.7f);
this.graph = graph;
if (Options.v().interactive_mode()){
InteractionHandler.v().handleCfgEvent(graph);
}
}
/**
* Returns the flow object corresponding to the initial values for
* each graph node.
*/
protected abstract A newInitialFlow();
/**
* Returns the initial flow value for entry/exit graph nodes.
*/
protected abstract A entryInitialFlow();
/**
* Determines whether entryInitialFlow()
* is applied to trap handlers.
*/
protected boolean treatTrapHandlersAsEntries() { return false; }
/** Returns true if this analysis is forwards. */
protected abstract boolean isForward();
/** Compute the merge of the in1 and in2 sets, putting the result into out.
* The behavior of this function depends on the implementation ( it may be necessary to check whether
* in1 and in2 are equal or aliased ).
* Used by the doAnalysis method. */
protected abstract void merge(A in1, A in2, A out);
/**
* Merges in1 and in2 into out, just before node succNode.
* By default, this method just calls merge(A,A,A), ignoring
* the node.
*/
protected void merge(N succNode, A in1, A in2, A out) {
merge(in1,in2,out);
}
/** Creates a copy of the source flow object in dest. */
protected abstract void copy(A source, A dest);
/** Carries out the actual flow analysis.
* Typically called from a concrete FlowAnalysis's constructor.*/
protected abstract void doAnalysis();
/** Accessor function returning value of IN set for s. */
public A getFlowBefore(N s)
{
return unitToBeforeFlow.get(s);
}
/**
* Merges in into inout, just before node succNode.
*/
protected void mergeInto(N succNode, A inout, A in) {
A tmp = newInitialFlow();
merge(succNode, inout, in, tmp);
copy(tmp, inout);
}
}