soot.toolkits.graph
Class MHGDominatorsFinder<N>

java.lang.Object
  soot.toolkits.graph.MHGDominatorsFinder<N>

All Implemented Interfaces:

DominatorsFinder<N>

Direct Known Subclasses:

MHGPostDominatorsFinder

public class MHGDominatorsFinder<N>
extends Object
implements DominatorsFinder<N>

Calculate dominators for basic blocks.

Uses the algorithm contained in Dragon book, pg. 670-1.

       D(n0) := { n0 }
       for n in N - { n0 } do D(n) := N;
       while changes to any D(n) occur do
         for n in N - {n0} do
             D(n) := {n} U (intersect of D(p) over all predecessors p of n)
 

2007/07/03 - updated to use BitSets instead of HashSets, as the most expensive operation in this algorithm used to be cloning of the fullSet, which is very cheap for BitSets.

Author:

Navindra Umanee, Eric Bodden

Field Summary

protected BitSet	fullSet
protected DirectedGraph<N>	graph
protected List<N>	heads
protected Map<Integer,N>	indexToNode
protected int	lastIndex
protected Map<N,BitSet>	nodeToFlowSet
protected Map<N,Integer>	nodeToIndex

Constructor Summary

MHGDominatorsFinder(DirectedGraph<N> graph)

Method Summary

protected void	doAnalysis()
List<N>	getDominators(Object node) Returns a list of dominators for the given node in the graph.
DirectedGraph<N>	getGraph() Returns the graph to which the analysis pertains.
N	getImmediateDominator(Object node) Returns the immediate dominator of node or null if the node has no immediate dominator.
protected int	indexOf(N o)
boolean	isDominatedBy(N node, N dominator) True if "node" is dominated by "dominator" in the graph.
boolean	isDominatedByAll(N node, Collection<N> dominators) True if "node" is dominated by all nodes in "dominators" in the graph.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

graph

protected DirectedGraph<N> graph

fullSet

protected BitSet fullSet

heads

protected List<N> heads

nodeToFlowSet

protected Map<N,BitSet> nodeToFlowSet

nodeToIndex

protected Map<N,Integer> nodeToIndex

indexToNode

protected Map<Integer,N> indexToNode

lastIndex

protected int lastIndex

Constructor Detail

MHGDominatorsFinder

public MHGDominatorsFinder(DirectedGraph<N> graph)

Method Detail

doAnalysis

protected void doAnalysis()

indexOf

protected int indexOf(N o)

getGraph

public DirectedGraph<N> getGraph()

Description copied from interface: DominatorsFinder

Returns the graph to which the analysis pertains.

Specified by:

getGraph in interface DominatorsFinder<N>

getDominators

public List<N> getDominators(Object node)

Description copied from interface: DominatorsFinder

Returns a list of dominators for the given node in the graph.

Specified by:

getDominators in interface DominatorsFinder<N>

getImmediateDominator

public N getImmediateDominator(Object node)

Description copied from interface: DominatorsFinder

Returns the immediate dominator of node or null if the node has no immediate dominator.

Specified by:

getImmediateDominator in interface DominatorsFinder<N>

isDominatedBy

public boolean isDominatedBy(N node,
                             N dominator)

Description copied from interface: DominatorsFinder

True if "node" is dominated by "dominator" in the graph.

Specified by:

isDominatedBy in interface DominatorsFinder<N>

isDominatedByAll

public boolean isDominatedByAll(N node,
                                Collection<N> dominators)

Description copied from interface: DominatorsFinder

True if "node" is dominated by all nodes in "dominators" in the graph.

Specified by:

isDominatedByAll in interface DominatorsFinder<N>