ExpressionMessage.cpp

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/* Copyright (c) 2005-2009 Rexx Language Association. All rights reserved.    */
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/*----------------------------------------------------------------------------*/
/******************************************************************************/
/* REXX Translator                                                            */
/*                                                                            */
/* Primitive Message Instruction Parse Class                                  */
/*                                                                            */
/******************************************************************************/
#include <stdlib.h>
#include "RexxCore.h"
#include "StringClass.hpp"
#include "QueueClass.hpp"
#include "RexxActivation.hpp"
#include "ExpressionMessage.hpp"
#include "Token.hpp"
#include "SourceFile.hpp"
#include "ProtectedObject.hpp"
 
RexxExpressionMessage::RexxExpressionMessage(
    RexxObject *_target,                /* message send target               */
    RexxString *name,                  /* message name                      */
    RexxObject *_super,                 /* message super class               */
    size_t      argCount,              /* count of positional arguments     */
    RexxQueue  *arglist,               /* message positional argument list  */
    size_t      namedArgCount,         /* count of named arguments          */
    RexxQueue  *namedArglist,          /* message named argument list       */
    bool        double_form)           /* type of message send              */
/******************************************************************************/
/*  Function:  Create a new message expression object                         */
/******************************************************************************/
{
                                         /* also make sure name is cleared    */
                                         /* name doubles as hash so ClearObjec*/
    this->messageName = OREF_NULL;            /* doesn't clear hash field.         */
 
    OrefSet(this, this->target, _target); /* fill in the target                */
    /* the message name                  */
    OrefSet(this, this->messageName, name->upper());
    OrefSet(this, this->super, _super);   /* the super class target            */
    doubleTilde = double_form;           // set the argument form
 
    /* get the count of positional arguments        */
    this->argumentCount = argCount;
    while (argCount > 0)               /* now copy the argument pointers    */
    {
        /* in reverse order                  */
        OrefSet(this, this->arguments[--argCount], arglist->pop());
    }
 
    // The named arguments are stored after the positional argument
    // Each named argument has 2 entries : name, expression
    // named_argument_count = the number of named arguments
    this->namedArgumentCount = namedArgCount;
    while (namedArgCount > 0)            /* now copy the argument pointers    */
    {
        /* in reverse order                  */
        --namedArgCount;
        OrefSet(this, this->arguments[this->argumentCount + (2 * namedArgCount) + 1], namedArglist->pop()); // expression
        OrefSet(this, this->arguments[this->argumentCount + (2 * namedArgCount) + 0], namedArglist->pop()); // name
    }
}
 
RexxObject *RexxExpressionMessage::evaluate(
    RexxActivation      *context,      /* current activation context        */
    RexxExpressionStack *stack )       /* evaluation stack                  */
/******************************************************************************/
/* Function:  Evaluate a message send in an expression                        */
/******************************************************************************/
{
    ProtectedObject result;              /* message expression result         */
    RexxObject *_super;                  /* target super class                */
    size_t      argcount;                /* count of positional arguments     */
    size_t      namedArgcount;           /* count of named arguments          */
    RexxObject *_target;                 /* message target                    */
    size_t      i;                       /* loop counter                      */
 
                                         /* evaluate the target               */
    _target = this->target->evaluate(context, stack);
    if (this->super != OREF_NULL)      /* have a message lookup override?   */
    {
#if 0
        if (_target != context->getReceiver())   /* sender and receiver different?    */
        {
            /* this is an error                  */
            reportException(Error_Execution_super);
        }
#endif
        /* get the variable value            */
        _super = this->super->evaluate(context, stack);
        stack->toss();                     /* pop the top item                  */
    }
    else
    {
        _super = OREF_NULL;                /* use the default lookup            */
    }
 
    // Positional arguments
    argcount = this->argumentCount;      /* get the argument count            */
    /* loop through the argument list    */
    for (i = 0; i < (size_t)argcount; i++)
    {
        /* real argument?                    */
        if (this->arguments[i] != OREF_NULL)
        {
            /* evaluate the expression           */
            RexxObject *resultArg = this->arguments[i]->evaluate(context, stack);
            /* trace if necessary                */
            context->traceIntermediate(resultArg, TRACE_PREFIX_ARGUMENT);
        }
        else
        {
            stack->push(OREF_NULL);          /* push an non-existent argument     */
                                             /* trace if necessary                */
            context->traceIntermediate(OREF_NULLSTRING, TRACE_PREFIX_ARGUMENT);
        }
    }
 
    // Named arguments
    namedArgcount = this->namedArgumentCount;
    for (i = argcount; i < argcount + (2 * namedArgcount); i+=2)
    {
        // Argument name: string literal
        RexxObject *name = this->arguments[i];
        stack->push(name); // a string
        context->traceIntermediate(name, TRACE_PREFIX_NAMED_ARGUMENT);
 
        // Argument expression
        RexxObject *argResult = this->arguments[i+1]->evaluate(context, stack);
        context->traceIntermediate(argResult, TRACE_PREFIX_ARGUMENT);
    }
 
    if (_super == OREF_NULL)             /* no super class override?          */
    {
                                         /* issue the fast message            */
        stack->send(this->messageName, argcount, namedArgcount, result);
    }
    else
    {
        /* evaluate the message w/override   */
        stack->send(this->messageName, _super, argcount, namedArgcount, result);
    }
    stack->popn(argcount + (2 * namedArgcount));  /* remove any arguments              */
 
    if (this->doubleTilde)               /* double twiddle form?              */
    {
        result = _target;                  /* get the target element            */
    }
    else
    {
        stack->prefixResult(result);       /* replace top element on stack      */
    }
 
    if ((RexxObject *)result == OREF_NULL)   /* in an expression and need a result*/
    {
                                         /* need to raise an exception        */
        reportException(Error_No_result_object_message, this->messageName);
    }
    /* trace if necessary                */
    context->traceMessage(messageName, (RexxObject *)result);
    return(RexxObject *)result;         /* return the result                 */
}
 
void RexxExpressionMessage::live(size_t liveMark)
/******************************************************************************/
/* Function:  Normal garbage collection live marking                          */
/******************************************************************************/
{
    size_t  i;                           /* loop counter                      */
    size_t  count;                       /* argument count                    */
 
    memory_mark(this->messageName);
    memory_mark(this->target);
    memory_mark(this->super);
    for (i = 0, count = this->argumentCount + (2 * this->namedArgumentCount); i < count; i++)
    {
        memory_mark(this->arguments[i]);
    }
}
 
void RexxExpressionMessage::liveGeneral(int reason)
/******************************************************************************/
/* Function:  Generalized object marking                                      */
/******************************************************************************/
{
    size_t  i;                           /* loop counter                      */
    size_t  count;                       /* argument count                    */
 
    memory_mark_general(this->messageName);
    memory_mark_general(this->target);
    memory_mark_general(this->super);
    for (i = 0, count = this->argumentCount + (2 * this->namedArgumentCount); i < count; i++)
    {
        memory_mark_general(this->arguments[i]);
    }
}
 
void RexxExpressionMessage::flatten(RexxEnvelope *envelope)
/******************************************************************************/
/* Function:  Flatten an object                                               */
/******************************************************************************/
{
    size_t  i;                           /* loop counter                      */
    size_t  count;                       /* argument count                    */
 
    setUpFlatten(RexxExpressionMessage)
 
    flatten_reference(newThis->messageName, envelope);
    flatten_reference(newThis->target, envelope);
    flatten_reference(newThis->super, envelope);
    for (i = 0, count = this->argumentCount + (2 * this->namedArgumentCount); i < count; i++)
    {
        flatten_reference(newThis->arguments[i], envelope);
    }
 
    cleanUpFlatten
}
 
void *RexxExpressionMessage::operator new(size_t size,
    size_t argCount)                   /* count of arguments                */
/******************************************************************************/
/* Function:  Create a new translator object                                  */
/******************************************************************************/
{
                                       /* Get new object                    */
  return new_object(size + (argCount - 1) * sizeof(RexxObject *), T_MessageSendTerm);
}
 
void RexxExpressionMessage::assign(
    RexxActivation *context,           /* current activation context        */
    RexxExpressionStack *stack,        /* current evaluation stack          */
    RexxObject     *value )            /* new value to assign               */
/******************************************************************************/
/* Function:  Emulate a variable assignment using a method                    */
/******************************************************************************/
{
    // evaluate the target
    RexxObject *_target = this->target->evaluate(context, stack);
    RexxObject *_super = OREF_NULL;
    // message override?
    if (this->super != OREF_NULL)
    {
        // in this context, the value needs to be SELF
        if (_target != context->getReceiver())
        {
            reportException(Error_Execution_super);
        }
        // evaluate the superclass override
        _super = this->super->evaluate(context, stack);
        stack->toss();
    }
    // push the assignment value on to the stack as the argument
    stack->push(value);
    // now push the rest of the arguments.  This might be something like a[1,2,3,4] as
    // an assignment term.  The assignment value is the first argument, followed by
    // any other arguments that are part of the encoded message term.
    size_t argcount = (size_t)this->argumentCount;
 
    for (size_t i = 0; i < argcount; i++)
    {
        // non-omitted argument?
        if (this->arguments[i] != OREF_NULL)
        {
            // evaluate and potentiall trace
            RexxObject *resultArg = this->arguments[i]->evaluate(context, stack);
            context->traceResult(resultArg);
        }
        else
        {
            // non existant arg....we may still need to trace that
            stack->push(OREF_NULL);
            context->traceResult(OREF_NULLSTRING);
        }
    }
 
    // Named arguments
    size_t namedArgcount = this->namedArgumentCount;
    for (size_t i = argcount; i < argcount + (2 * namedArgcount); i+=2)
    {
        // Argument name: string literal
        RexxObject *name = this->arguments[i];
        stack->push(name); // a string
        context->traceIntermediate(name, TRACE_PREFIX_NAMED_ARGUMENT);
 
        // Argument expression
        RexxObject *argResult = this->arguments[i+1]->evaluate(context, stack);
        context->traceIntermediate(argResult, TRACE_PREFIX_ARGUMENT);
    }
 
    ProtectedObject result;
 
    // now send the message the appropriate way
    if (_super == OREF_NULL)
    {
        // normal message send
        stack->send(this->messageName, argcount + 1, namedArgcount, result);
    }
    else
    {
        // send with an override
        stack->send(this->messageName, _super, argcount + 1, namedArgcount, result);
    }
                                       /* trace if necessary                */
    context->traceAssignment(messageName, (RexxObject *)result);
    // remove all arguments (arguments + target + assignment value)
    // and all named arguments
    stack->popn((argcount + 2) + ((2 * namedArgcount)));
}
 
 
 
/**
 * Convert a message into an assignment message by adding "="
 * to the end of the message name.
 *
 * @param source The current source context.
 */
void RexxExpressionMessage::makeAssignment(RexxSource *source)
{
    // add an equal sign to the name
    messageName = source->commonString(messageName->concat(OREF_EQUAL));
}