Package edu.umd.cs.findbugs.ba

Class BasicAbstractDataflowAnalysis<Fact>

java.lang.Object
edu.umd.cs.findbugs.ba.BasicAbstractDataflowAnalysis<Fact>
All Implemented Interfaces:
DataflowAnalysis<Fact>
Direct Known Subclasses:
AbstractDataflowAnalysis, AbstractDominatorsAnalysis, BlockTypeAnalysis, ReturnPathTypeAnalysis
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 Details

    • BasicAbstractDataflowAnalysis

      public BasicAbstractDataflowAnalysis()
      Constructor.

  • Method Details

    • resultFactIterator

      public Iterator<Fact> resultFactIterator()
      Get an iterator over the result facts.

    • factToString

      public String factToString(Fact fact)
      Description copied from interface: DataflowAnalysis
      Return a String representation of given Fact. For debugging purposes.
      Specified by:
      factToString in interface DataflowAnalysis<Fact>
      Parameters:
      fact - a dataflow fact
      Returns:
      String representation of the fact

    • getStartFact

      public Fact getStartFact(BasicBlock block)
      Description copied from interface: DataflowAnalysis
      Get the start fact for given basic block.
      Specified by:
      getStartFact in interface DataflowAnalysis<Fact>
      Parameters:
      block - the basic block

    • getResultFact

      public Fact getResultFact(BasicBlock block)
      Description copied from interface: DataflowAnalysis
      Get the result fact for given basic block.
      Specified by:
      getResultFact in interface DataflowAnalysis<Fact>
      Parameters:
      block - the basic block

    • getFactAtLocation

      public Fact getFactAtLocation(Location location) throws DataflowAnalysisException
      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.

      Specified by:
      getFactAtLocation in interface DataflowAnalysis<Fact>
      Parameters:
      location - the Location
      Returns:
      the dataflow value at given Location
      Throws:
      DataflowAnalysisException

    • getFactAfterLocation

      public Fact getFactAfterLocation(Location location) throws DataflowAnalysisException
      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.

      Specified by:
      getFactAfterLocation in interface DataflowAnalysis<Fact>
      Parameters:
      location - the Location
      Returns:
      the dataflow value after given Location
      Throws:
      DataflowAnalysisException

    • getFactOnEdge

      public Fact getFactOnEdge(Edge edge) throws DataflowAnalysisException
      Get the fact that is true on the given control edge, after applying the edge transfer function (if any).
      Specified by:
      getFactOnEdge in interface DataflowAnalysis<Fact>
      Parameters:
      edge - the edge
      Returns:
      the fact that is true after applying the edge transfer function
      Throws:
      DataflowAnalysisException

    • startIteration

      public void startIteration()
      Description copied from interface: DataflowAnalysis
      Called before beginning an iteration of analysis. Each iteration visits every basic block in the CFG.
      Specified by:
      startIteration in interface DataflowAnalysis<Fact>

    • finishIteration

      public void finishIteration()
      Description copied from interface: DataflowAnalysis
      Called after finishing an iteration of analysis.
      Specified by:
      finishIteration in interface DataflowAnalysis<Fact>

    • edgeTransfer

      public void edgeTransfer(Edge edge, Fact fact) throws DataflowAnalysisException
      Description copied from interface: DataflowAnalysis
      Edge transfer function. Modify the given fact that is true on the (logical) edge source to modify it so that it is true at the (logical) edge target.

      A do-nothing implementation is legal, and appropriate for analyses where branches are not significant.

      Specified by:
      edgeTransfer in interface DataflowAnalysis<Fact>
      Parameters:
      edge - the Edge
      fact - a dataflow fact
      Throws:
      DataflowAnalysisException

    • getLastUpdateTimestamp

      public int getLastUpdateTimestamp(Fact fact)
      Specified by:
      getLastUpdateTimestamp in interface DataflowAnalysis<Fact>

    • setLastUpdateTimestamp

      public void setLastUpdateTimestamp(Fact fact, int lastUpdateTimestamp)
      Specified by:
      setLastUpdateTimestamp in interface DataflowAnalysis<Fact>