AssignmentInstruction.cpp

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/*----------------------------------------------------------------------------*/
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/* Copyright (c) 2005-2009 Rexx Language Association. All rights reserved.    */
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/*----------------------------------------------------------------------------*/
/******************************************************************************/
/* REXX Translator                                                            */
/*                                                                            */
/* Primitive Assignment Parse Class                                           */
/*                                                                            */
/******************************************************************************/
#include <stdlib.h>
#include "RexxCore.h"
#include "ExpressionBaseVariable.hpp"
#include "RexxActivation.hpp"
#include "AssignmentInstruction.hpp"
 
RexxInstructionAssignment::RexxInstructionAssignment(
    RexxVariableBase *target,          /* target variable instruction       */
    RexxObject       *_expression)      /* assigned expression value         */
/******************************************************************************/
/* Function:  complete ASSIGNMENT instruction initialization                  */
/******************************************************************************/
{
                                       /* get the variable target           */
  OrefSet(this, this->variable, target);
                                       /* process the expression            */
  OrefSet(this, this->expression, _expression);
}
 
void RexxInstructionAssignment::live(size_t liveMark)
/******************************************************************************/
/* Function:  Normal garbage collection live marking                          */
/******************************************************************************/
{
  memory_mark(this->nextInstruction);  /* must be first one marked          */
  memory_mark(this->variable);
  memory_mark(this->expression);
}
 
void RexxInstructionAssignment::liveGeneral(int reason)
/******************************************************************************/
/* Function:  Generalized object marking                                      */
/******************************************************************************/
{
                                       /* must be first one marked          */
  memory_mark_general(this->nextInstruction);
  memory_mark_general(this->variable);
  memory_mark_general(this->expression);
}
 
void RexxInstructionAssignment::flatten(RexxEnvelope *envelope)
/******************************************************************************/
/* Function:  Flatten an object                                               */
/******************************************************************************/
{
  setUpFlatten(RexxInstructionAssignment)
 
  flatten_reference(newThis->nextInstruction, envelope);
  flatten_reference(newThis->variable, envelope);
  flatten_reference(newThis->expression, envelope);
 
  cleanUpFlatten
}
 
void RexxInstructionAssignment::execute(
    RexxActivation      *context,      /* current activation context        */
    RexxExpressionStack *stack)        /* evaluation stack                  */
/******************************************************************************/
/* Function:  Execute a REXX assignment instruction                           */
/*            NOTE:  This instruction is implemented using two seperate paths */
/*            for traced vs. non-traced execution.  This reduces the checks   */
/*            for non-traced execution to a single check in this very         */
/*            heavily executed instruction.                                   */
/******************************************************************************/
{
    RexxObject *result;
    if (context->tracingInstructions())/* tracing?                          */
    {
        context->traceInstruction(this);   /* trace if necessary                */
                                           /* get the expression value          */
        if (this->expression == OREF_NULL) result = OREF_NULLSTRING; // Compatibility: v= is a shortcut of v=""
        else result = this->expression->evaluate(context, stack);
        context->traceResult(result);      /* trace if necessary                */
                                           /* do the assignment                 */
        this->variable->assign(context, stack, result);
        context->pauseInstruction();       /* do debug pause if necessary       */
    }
    else                                 /* non-traced execution              */
    {
        if (this->expression == OREF_NULL) result = OREF_NULLSTRING; // Compatibility: v= is a shortcut of v=""
        else result = this->expression->evaluate(context, stack);
                                         /* do the assignment                 */
        this->variable->assign(context, stack, result);
    }
}