Package com.adobe.xfa.formcalc

Class Instruction

  • public final class Instruction
extends java.lang.Object
    The class Instruction defines all the instructions that the FormCalc virtual machine is capable of executing, as a collection of static methods. Each instruction corresponds to an opcode of this virtual machine.

    An execution path of the virtual machine is just a sequence of instructions stored in FormCalc's virtual code space. Each sequence is terminated with an Stop instruction, to represent the end of an execution path.

    All instructions have a common interface, consisting of: a the FormCalc YYPARSENAME. Since the FormCalc virtual machine is a stack machine, i.e., its fetches its operand(s) from a runtime stack, and pushes its result back onto the runtime stack, most instructions are single word instructions. A few instructions, like Load, In, Out and Call are multi-word instructions -- some of their operands are stored in the words following the opcode. Other instructions, like If, For and While, also multi-word instructions, contain control flow information to the different execution paths inherent of conditional and iterative instructions.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean debugBreakPoint​(int nScriptID, int nLine, boolean bSet)
      Set or clear a debug break-point.
      boolean debugCommand​(com.adobe.xfa.formcalc.CalcParser oParser, int eCmd)
      Set internal state to enable either step-over, step-into or step-out.

      • Methods inherited from class java.lang.Object

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

    • Method Detail

      • debugBreakPoint

        public boolean debugBreakPoint​(int nScriptID,
                               int nLine,
                               boolean bSet)
        Set or clear a debug break-point. It sets or clears a flag in the moDebugLineNo array, which is an array of line numbers parallel to the moCodeBase array.
        Parameters:
        nLine - line of source code.
        bSet - true to set a break-point, false to clear it.
        Returns:
        true if successful.

      • debugCommand

        public boolean debugCommand​(com.adobe.xfa.formcalc.CalcParser oParser,
                            int eCmd)
        Set internal state to enable either step-over, step-into or step-out. The debug-mode execution loop calls the debug host's Stopped method when mnDebugStopAtStackDepth is greater than or equal to the current stack depth.
        Parameters:
        oParser - the FormCalc parser.
        eCmd - a value of the CalcDebugCommand enum representing step-over, step-into or step-out.
        Returns:
        true if successful.