com.ibm.wala.dataflow.IFDS

Class LocalPathEdges

java.lang.Object

com.ibm.wala.dataflow.IFDS.LocalPathEdges

public class LocalPathEdges
extends java.lang.Object

A set of path edges for a particular procedure entry s_p.

Constructor Summary

Constructors

Constructor and Description
LocalPathEdges(boolean fastMerge)

Method Summary

Modifier and Type	Method and Description
void	addPathEdge(int i, int n, int j) Record that in this procedure we've discovered a same-level realizable path from (s_p,d_i) to (n,d_j)
boolean	contains(int i, int n, int j)
com.ibm.wala.util.intset.IntSet	getInverse(int n, int d2) N.B: If we're using the ZERO_PATH_SHORT_CIRCUIT, then we may have <s_p, d1> -> <n, d2> implicitly represented since we also have <s_p, 0> -> <n,d2>.
com.ibm.wala.util.intset.IntSet	getReachable(int n) TODO: optimize this based on altPaths
com.ibm.wala.util.intset.IntSet	getReachable(int n, int d1)
com.ibm.wala.util.intset.IntSet	getReachedNodeNumbers() TODO: optimize this

Methods inherited from class java.lang.Object

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

Constructor Detail

LocalPathEdges

public LocalPathEdges(boolean fastMerge)

Parameters:

fastMerge - if true, the representation uses extra space in order to support faster merge operations

Method Detail

addPathEdge

public void addPathEdge(int i,
                        int n,
                        int j)

Record that in this procedure we've discovered a same-level realizable path from (s_p,d_i) to (n,d_j)

Parameters:

n - local block number of the basic block n

getInverse

public com.ibm.wala.util.intset.IntSet getInverse(int n,
                                                  int d2)

N.B: If we're using the ZERO_PATH_SHORT_CIRCUIT, then we may have <s_p, d1> -> <n, d2> implicitly represented since we also have <s_p, 0> -> <n,d2>. However, getInverse() <b> will NOT </b> return these implicit d1 bits in the result. This translates to saying that the caller had better not care about any other d1 other than d1==0 if d1==0 is present. This happens to be true in the single use of getInverse() in the tabulation solver, which uses getInverse() to propagate flow from an exit node back to the caller's return site(s). Since we know that we will see flow from fact 0 to the return sites(s), we don't care about other facts that may induce the same flow to the return site(s).

Parameters:

n - local block number of a basic block n

Returns:

the sparse int set of d1 s.t. <s_p, d1> -> <n, d2> are recorded as path edges. null if none found

contains

public boolean contains(int i,
                        int n,
                        int j)

Parameters:

n - local block number of a basic block n

Returns:

true iff we have a path edge <s_p,i> -> <n, j>

getReachable

public com.ibm.wala.util.intset.IntSet getReachable(int n,
                                                    int d1)

Returns:

set of d2 s.t. d1 -> d2 is a path edge for node n.

getReachable

public com.ibm.wala.util.intset.IntSet getReachable(int n)

TODO: optimize this based on altPaths

Parameters:

n - the local block number of a node

Returns:

set of d2 s.t \exists d1 s.t. d1 -> d2 is a path edge for node n

getReachedNodeNumbers

public com.ibm.wala.util.intset.IntSet getReachedNodeNumbers()

TODO: optimize this

Returns:

set of node numbers that are reached by any fact