Class Edge

java.lang.Object
org.datanucleus.enhancer.asm.Edge

final class Edge extends 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.
See Also:
  • Field Summary

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

    Constructors
    Constructor
    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 Details

    • 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:
    • EXCEPTION

      static final int EXCEPTION
      A control flow graph edge corresponding to an exception handler. Only used with ClassWriter.COMPUTE_MAXS.
      See Also:
    • 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 Details

    • Edge

      Edge(int info, Label successor, Edge nextEdge)
      Constructs a new Edge.
      Parameters:
      info - see info.
      successor - see successor.
      nextEdge - see nextEdge.