org.springframework.asm

Class Edge

java.lang.Object

org.springframework.asm.Edge

final class Edge
extends java.lang.Object

An edge in the control flow graph of a method. Each node of this graph is a basic block, represented with the Label corresponding to its first instruction. Each edge goes from one node to another, i.e. from one basic block to another (called the predecessor and successor blocks, respectively). An edge corresponds either to a jump or ret instruction or to an exception handler.

Author:

Eric Bruneton

See Also:

Label

Field Summary

Fields

Modifier and Type	Field and Description
(package private) static int	EXCEPTION A control flow graph edge corresponding to an exception handler.
(package private) int	info Information about this control flow graph edge.
(package private) static int	JUMP A control flow graph edge corresponding to a jump or ret instruction.
(package private) Edge	nextEdge The next edge in the list of outgoing edges of a basic block.
(package private) Label	successor The successor block of this control flow graph edge.

Constructor Summary

Constructors

Constructor and Description
Edge(int info, Label successor, Edge nextEdge) Constructs a new Edge.

Method Summary

Methods inherited from class java.lang.Object

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

Field Detail

JUMP

static final int JUMP

A control flow graph edge corresponding to a jump or ret instruction. Only used with ClassWriter.COMPUTE_FRAMES.

See Also:

Constant Field Values

EXCEPTION

static final int EXCEPTION

A control flow graph edge corresponding to an exception handler. Only used with ClassWriter.COMPUTE_MAXS.

See Also:

Constant Field Values

info

final int info

Information about this control flow graph edge.

• If ClassWriter.COMPUTE_MAXS is used, this field contains either a stack size delta (for an edge corresponding to a jump instruction), or the value EXCEPTION (for an edge corresponding to an exception handler). The stack size delta is the stack size just after the jump instruction, minus the stack size at the beginning of the predecessor basic block, i.e. the one containing the jump instruction.
• If ClassWriter.COMPUTE_FRAMES is used, this field contains either the value JUMP (for an edge corresponding to a jump instruction), or the index, in the ClassWriter type table, of the exception type that is handled (for an edge corresponding to an exception handler).

successor

final Label successor

The successor block of this control flow graph edge.

nextEdge

Edge nextEdge

The next edge in the list of outgoing edges of a basic block. See Label.outgoingEdges.

Constructor Detail

Edge

Edge(int info,
     Label successor,
     Edge nextEdge)

Constructs a new Edge.

Parameters:

info - see info.

successor - see successor.

nextEdge - see nextEdge.