edu.umd.cs.findbugs.ba

Class BasicAbstractDataflowAnalysis<Fact>

public abstract class BasicAbstractDataflowAnalysis<Fact> extends Object implements DataflowAnalysis<Fact>

A useful starting point for defining a dataflow analysis. Handles access and caching of start and result facts for basic blocks.

Subclasses that model instructions within basic blocks should extend AbstractDataflowAnalysis.

Author: David Hovemeyer

Constructor Summary
	BasicAbstractDataflowAnalysis() Constructor.

Method Summary
void	edgeTransfer(Edge edge, Fact fact)
String	factToString(Fact fact) Call this to get a dataflow value as a String.
void	finishIteration()
Fact	getFactAfterLocation(Location location) Get the dataflow fact representing the point just after given Location.
Fact	getFactAtLocation(Location location) Get dataflow fact at (just before) given Location.
Fact	getFactOnEdge(Edge edge) Get the fact that is true at the target of the given control edge.
int	getLastUpdateTimestamp(Fact fact)
Fact	getResultFact(BasicBlock block)
Fact	getStartFact(BasicBlock block)
Iterator<Fact>	resultFactIterator() Get an iterator over the result facts.
void	setLastUpdateTimestamp(Fact fact, int lastUpdateTimestamp)
void	startIteration()

Constructor Detail

BasicAbstractDataflowAnalysis

public BasicAbstractDataflowAnalysis()

Constructor.

Method Detail

edgeTransfer

public void edgeTransfer(Edge edge, Fact fact)

factToString

public String factToString(Fact fact)

Call this to get a dataflow value as a String. By default, we just call toString(). Subclasses may override to get different behavior.

getFactAfterLocation

public Fact getFactAfterLocation(Location location)

Get the dataflow fact representing the point just after given Location. Note "after" is meant in the logical sense, so for backward analyses, after means before the location in the control flow sense.

The default implementation ignores instructions within basic blocks. Subclasses that model individual instructions must override this method.

Parameters: location the Location

Returns: the dataflow value after given Location

Throws: DataflowAnalysisException

getFactAtLocation

public Fact getFactAtLocation(Location location)

Get dataflow fact at (just before) given Location. Note "before" is meant in the logical sense, so for backward analyses, before means after the location in the control flow sense.

The default implementation ignores instructions within basic blocks. Subclasses that model individual instructions must override this method.

Parameters: location the Location

Returns: the dataflow value at given Location

Throws: DataflowAnalysisException

getFactOnEdge

public Fact getFactOnEdge(Edge edge)

Get the fact that is true at the target of the given control edge.

Parameters: edge the edge

Returns: the fact that is true at the target of the edge

Throws: DataflowAnalysisException