Class PruneInfeasibleExceptionEdges

java.lang.Object

edu.umd.cs.findbugs.ba.PruneInfeasibleExceptionEdges

All Implemented Interfaces:

EdgeTypes

public class PruneInfeasibleExceptionEdges
extends Object
implements EdgeTypes

Prune a CFG to remove infeasible exception edges. In order to determine what kinds of exceptions can be thrown by explicit ATHROW instructions, type analysis must first be performed on the unpruned CFG.

See Also:

• CFG
• TypeAnalysis

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	PruneInfeasibleExceptionEdges.MarkedEdge	A memento to remind us of how we classified a particular exception edge.

Field Summary

Fields

Modifier and Type	Field	Description
private final CFG	cfg
private boolean	cfgModified
private static final boolean	DEBUG
private static int	numEdgesPruned
private static final boolean	STATS
private final TypeDataflow	typeDataflow

Fields inherited from interface EdgeTypes

BACKEDGE_SOURCE_EDGE, BACKEDGE_TARGET_EDGE, CHECKED_EXCEPTIONS_FLAG, EXIT_EDGE, EXPLICIT_EXCEPTIONS_FLAG, FALL_THROUGH_EDGE, GOTO_EDGE, HANDLED_EXCEPTION_EDGE, IFCMP_EDGE, JSR_EDGE, RET_EDGE, RETURN_EDGE, START_EDGE, SWITCH_DEFAULT_EDGE, SWITCH_EDGE, UNHANDLED_EXCEPTION_EDGE, UNKNOWN_EDGE

Constructor Summary

Constructors

Constructor	Description
PruneInfeasibleExceptionEdges(CFG cfg, org.apache.bcel.generic.MethodGen methodGen, TypeDataflow typeDataflow)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	execute()	Prune infeasible exception edges from the CFG.
boolean	wasCFGModified()

Methods inherited from class Object

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

Field Details

DEBUG

private static final boolean DEBUG

STATS

private static final boolean STATS

numEdgesPruned

private static int numEdgesPruned

cfg

private final CFG cfg

typeDataflow

private final TypeDataflow typeDataflow

cfgModified

private boolean cfgModified

Constructor Details

PruneInfeasibleExceptionEdges

public PruneInfeasibleExceptionEdges(CFG cfg,
 org.apache.bcel.generic.MethodGen methodGen,
 TypeDataflow typeDataflow)

Constructor.

Parameters:

cfg - the CFG to prune

methodGen - the method

typeDataflow - initialized TypeDataflow object for the CFG, indicating the types of all stack locations

Method Details

execute

public void execute()
             throws ClassNotFoundException

Prune infeasible exception edges from the CFG. If the method returns normally, then the operation was successful, and the CFG should no longer contain infeasible exception edges. If ClassNotFoundException or DataflowAnalysisException are thrown, then the operation was unsuccessful, but the CFG is still valid because it was not modified. If a runtime exception is thrown, then the CFG may be partially modified and should be considered invalid.

Throws:

ClassNotFoundException

wasCFGModified

public boolean wasCFGModified()

Returns:

true if modified