polyglot.visit
Class FlowGraph

java.lang.Object
  polyglot.visit.FlowGraph

public class FlowGraph
extends java.lang.Object

Nested Class Summary

static class	FlowGraph.Edge This class represents an edge in the flow graph.
static class	FlowGraph.EdgeKey This class provides an identifying label for edges in the flow graph.
static class	FlowGraph.ExceptionEdgeKey This class extends EdgeKey and is the key for edges that are taken when an exception of type t is thrown.
protected static class	FlowGraph.ListKey Class to be used for inserting Lists in hashtables using collection equality (as defined in CollectionUtil).
static class	FlowGraph.Peer A Peer is an occurance of an AST node in a flow graph.

Field Summary

static FlowGraph.EdgeKey	EDGE_KEY_FALSE This EdgeKey is the EdgeKey for edges where the expression evaluates to false.
static FlowGraph.EdgeKey	EDGE_KEY_OTHER This EdgeKey is the EdgeKey for edges where the flow is not suitable for EDGE_KEY_TRUE, EDGE_KEY_FALSE or an ExceptionEdgeKey, such as the edges from a switch statement to its cases and the flow from a sink node in the control flow graph.
static FlowGraph.EdgeKey	EDGE_KEY_TRUE This EdgeKey is the EdgeKey for edges where the expression evaluates to true.
protected boolean	forward Is the flow in this flow graph forward or backward?
protected java.util.Map	peerMap Maps from AST nodes to path maps and hence to Peers that represent occurrences of the AST node in the flow graph.
protected Term	root The root of the AST that this is a flow graph for.

Method Summary

Term	entryNode()
Term	exitNode()
Term	finishNode()
boolean	forward()
java.util.Map	pathMap(Node n)
java.util.Collection	pathMaps()
FlowGraph.Peer	peer(Term n, DataFlow df) Retrieve the Peer for the Term n, where n does not appear in a finally block.
FlowGraph.Peer	peer(Term n, java.util.List path_to_finally, DataFlow df) Retrieve the Peer for the Term n that is associated with the given path to the finally block.
java.util.Collection	peers() Return a collection of all Peers in this flow graph.
java.util.Collection	peers(Term n) Return a collection of all of the Peers for the given Term n.
Term	root()
Term	startNode()
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

peerMap

protected java.util.Map peerMap

Maps from AST nodes to path maps and hence to Peers that represent occurrences of the AST node in the flow graph. In particular, peerMap maps IdentityKey(Node)s to path maps. A path map is a map from paths (ListKey(List of Terms)) to Peers. In particular, if n is an AST node in a finally block, then there will be a Peer of n for each possible path to the finally block, and the path map records which Peer corresponds to which path. If n does not occur in a finally block, then the path map should have only a single entry, from an empty list to the unique Peer for n.

WARNING: the AST must be a tree, not a DAG. Otherwise the same peer may be used for a node that appears at multiple points in the AST. These points may have different data flows.

root

protected Term root

The root of the AST that this is a flow graph for.

forward

protected boolean forward

Is the flow in this flow graph forward or backward?

EDGE_KEY_TRUE

public static final FlowGraph.EdgeKey EDGE_KEY_TRUE

This EdgeKey is the EdgeKey for edges where the expression evaluates to true.

EDGE_KEY_FALSE

public static final FlowGraph.EdgeKey EDGE_KEY_FALSE

This EdgeKey is the EdgeKey for edges where the expression evaluates to false.

EDGE_KEY_OTHER

public static final FlowGraph.EdgeKey EDGE_KEY_OTHER

This EdgeKey is the EdgeKey for edges where the flow is not suitable for EDGE_KEY_TRUE, EDGE_KEY_FALSE or an ExceptionEdgeKey, such as the edges from a switch statement to its cases and the flow from a sink node in the control flow graph.

Method Detail

startNode

public Term startNode()

finishNode

public Term finishNode()

entryNode

public Term entryNode()

exitNode

public Term exitNode()

root

public Term root()

forward

public boolean forward()

pathMaps

public java.util.Collection pathMaps()

pathMap

public java.util.Map pathMap(Node n)

peers

public java.util.Collection peers()

Return a collection of all Peers in this flow graph.

peer

public FlowGraph.Peer peer(Term n,
                           DataFlow df)

Retrieve the Peer for the Term n, where n does not appear in a finally block. If no such Peer exists, then one will be created.

Parameters:

df - unused; for legacy purposes only?

peers

public java.util.Collection peers(Term n)

Return a collection of all of the Peers for the given Term n.

peer

public FlowGraph.Peer peer(Term n,
                           java.util.List path_to_finally,
                           DataFlow df)

Retrieve the Peer for the Term n that is associated with the given path to the finally block. (A term that occurs in a finally block has one Peer for each possible path to that finally block.) If no such Peer exists, then one will be created.

Parameters:

df - unused; for legacy purposes only?

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object