Package edu.umd.cs.findbugs.ba.obl

Class ObligationAnalysis

java.lang.Object

edu.umd.cs.findbugs.ba.BasicAbstractDataflowAnalysis<Fact>

edu.umd.cs.findbugs.ba.AbstractDataflowAnalysis<Fact>

edu.umd.cs.findbugs.ba.ForwardDataflowAnalysis<StateSet>

edu.umd.cs.findbugs.ba.obl.ObligationAnalysis

All Implemented Interfaces:

DataflowAnalysis<StateSet>

public class ObligationAnalysis
extends ForwardDataflowAnalysis<StateSet>

Dataflow analysis to track obligations (i/o streams and other resources which must be closed).

See Weimer and Necula, Finding and preventing run-time error handling mistakes, OOPSLA 2004.

Author:

David Hovemeyer

Constructor Summary

Constructors

Constructor	Description
ObligationAnalysis(DepthFirstSearch dfs, XMethod xmethod, org.apache.bcel.generic.ConstantPoolGen cpg, ObligationFactory factory, ObligationPolicyDatabase database, TypeDataflow typeDataflow, IsNullValueDataflow invDataflow, IErrorLogger errorLogger)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	copy(StateSet src, StateSet dest)	Copy dataflow facts.
StateSet	createFact()	Create empty (uninitialized) dataflow facts for one program point.
void	edgeTransfer(Edge edge, StateSet fact)	Edge transfer function.
InstructionActionCache	getActionCache()
void	initEntryFact(StateSet fact)	Initialize the "entry" fact for the graph.
boolean	isFactValid(StateSet fact)	Determine whether the given fact is valid (neither top nor bottom).
boolean	isTop(StateSet fact)	Is the given fact the top value.
void	makeFactTop(StateSet fact)	Make given fact the top value.
void	meetInto(StateSet fact, Edge edge, StateSet result)	Meet a dataflow fact associated with an incoming edge into another fact.
boolean	same(StateSet a, StateSet b)	Are given dataflow facts the same?
void	transfer(BasicBlock basicBlock, org.apache.bcel.generic.InstructionHandle end, StateSet start, StateSet result)	Transfer function for the analysis.
void	transferInstruction(org.apache.bcel.generic.InstructionHandle handle, BasicBlock basicBlock, StateSet fact)	Transfer function for a single instruction.

Methods inherited from class edu.umd.cs.findbugs.ba.ForwardDataflowAnalysis

getBlockOrder, getDepthFirstSearch, isForwards

Methods inherited from class edu.umd.cs.findbugs.ba.AbstractDataflowAnalysis

getFactAfterLocation, getFactAtLocation

Methods inherited from class edu.umd.cs.findbugs.ba.BasicAbstractDataflowAnalysis

factToString, finishIteration, getFactOnEdge, getLastUpdateTimestamp, getResultFact, getStartFact, resultFactIterator, setLastUpdateTimestamp, startIteration

Methods inherited from class java.lang.Object

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

Constructor Detail

ObligationAnalysis

public ObligationAnalysis(DepthFirstSearch dfs,
                          XMethod xmethod,
                          org.apache.bcel.generic.ConstantPoolGen cpg,
                          ObligationFactory factory,
                          ObligationPolicyDatabase database,
                          TypeDataflow typeDataflow,
                          IsNullValueDataflow invDataflow,
                          IErrorLogger errorLogger)

Constructor.

Parameters:

dfs - a DepthFirstSearch on the method to be analyzed

xmethod - method to analyze

cpg - ConstantPoolGen of the method to be analyzed

factory - the ObligationFactory defining the obligation types

database - the PolicyDatabase defining the methods which add and delete obligations

errorLogger - callback to use when reporting missing classes

Method Detail

getActionCache

public InstructionActionCache getActionCache()

createFact

public StateSet createFact()

Description copied from interface: DataflowAnalysis

Create empty (uninitialized) dataflow facts for one program point. A valid value will be copied into it before it is used.

isFactValid

public boolean isFactValid(StateSet fact)

Description copied from class: AbstractDataflowAnalysis

Determine whether the given fact is valid (neither top nor bottom).

Specified by:

isFactValid in class AbstractDataflowAnalysis<StateSet>

transferInstruction

public void transferInstruction(org.apache.bcel.generic.InstructionHandle handle,
                                BasicBlock basicBlock,
                                StateSet fact)
                         throws DataflowAnalysisException

Description copied from class: AbstractDataflowAnalysis

Transfer function for a single instruction.

Specified by:

transferInstruction in class AbstractDataflowAnalysis<StateSet>

Parameters:

handle - the instruction

basicBlock - the BasicBlock containing the instruction; needed to disambiguate instructions in inlined JSR subroutines

fact - which should be modified based on the instruction

Throws:

DataflowAnalysisException

transfer

public void transfer(BasicBlock basicBlock,
                     @CheckForNull
                     org.apache.bcel.generic.InstructionHandle end,
                     StateSet start,
                     StateSet result)
              throws DataflowAnalysisException

Description copied from interface: DataflowAnalysis

Transfer function for the analysis. Taking dataflow facts at start (which might be either the entry or exit of the block, depending on whether the analysis is forwards or backwards), modify result to be the facts at the other end of the block.

Specified by:

transfer in interface DataflowAnalysis<StateSet>

Overrides:

transfer in class AbstractDataflowAnalysis<StateSet>

Parameters:

basicBlock - the basic block

end - if nonnull, stop before considering this instruction; otherwise, consider all of the instructions in the basic block

start - dataflow facts at beginning of block (if forward analysis) or end of block (if backwards analysis)

result - resulting dataflow facts at other end of block

Throws:

DataflowAnalysisException

edgeTransfer

public void edgeTransfer(Edge edge,
                         StateSet 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<StateSet>

Overrides:

edgeTransfer in class BasicAbstractDataflowAnalysis<StateSet>

Parameters:

edge - the Edge

fact - a dataflow fact

Throws:

DataflowAnalysisException

copy

public void copy(StateSet src,
                 StateSet dest)

Description copied from interface: DataflowAnalysis

Copy dataflow facts.

initEntryFact

public void initEntryFact(StateSet fact)
                   throws DataflowAnalysisException

Description copied from interface: DataflowAnalysis

Initialize the "entry" fact for the graph.

Throws:

DataflowAnalysisException

makeFactTop

public void makeFactTop(StateSet fact)

Description copied from interface: DataflowAnalysis

Make given fact the top value.

isTop

public boolean isTop(StateSet fact)

Description copied from interface: DataflowAnalysis

Is the given fact the top value.

same

public boolean same(StateSet a,
                    StateSet b)

Description copied from interface: DataflowAnalysis

Are given dataflow facts the same?

meetInto

public void meetInto(StateSet fact,
                     Edge edge,
                     StateSet result)
              throws DataflowAnalysisException

Description copied from interface: DataflowAnalysis

Meet a dataflow fact associated with an incoming edge into another fact. This is used to determine the start fact for a basic block.

Parameters:

fact - the predecessor fact (incoming edge)

edge - the edge from the predecessor

result - the result fact

Throws:

DataflowAnalysisException