/*
  Copyright 2003 Ronald S. Burkey <info@sandroid.org>
  
  This file is part of yaAGC. 

  yaAGC is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  yaAGC is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with yaAGC; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

  Filename:	ParseECADR.c
  Purpose:	Assembles the ECADR pseudo-ops.
  Mode:		04/27/03 RSB.	Began.
*/

#include "yaYUL.h"
#include <stdlib.h>
#include <math.h>
#include <string.h>

//-------------------------------------------------------------------------
// Returns non-zero on unrecoverable error.

int
ParseECADR (ParseInput_t *InRecord, ParseOutput_t *OutRecord)
{
  Address_t Address;
  int Value, i;

  IncPc(&InRecord->ProgramCounter, 1, &OutRecord->ProgramCounter);

  if (!OutRecord->ProgramCounter.Invalid && OutRecord->ProgramCounter.Overflow)
    {
      strcpy (OutRecord->ErrorMessage, "Next code may overflow storage.");
      OutRecord->Warning = 1;
    }

  OutRecord->EBank = InRecord->EBank;
  OutRecord->SBank = InRecord->SBank;
  OutRecord->NumWords = 1;
  OutRecord->Words[0] = 0;

  if (InRecord->Extend && !InRecord->IndexValid)
    {
      strcpy (OutRecord->ErrorMessage, "Illegally preceded by EXTEND.");
      OutRecord->Fatal = 1;
      OutRecord->Extend = 0;
    }

  if (InRecord->IndexValid)
    {
      strcpy (OutRecord->ErrorMessage, "Illegally preceded by INDEX.");
      OutRecord->Fatal = 1;
      OutRecord->IndexValid = 0;
    }

  i = GetOctOrDec (InRecord->Operand, &Value);
  if (!i && *InRecord->Mod1 == 0)
    {
      IncPc (&InRecord->ProgramCounter, Value, &Address);

    DoIt:  
      if (Address.Invalid)
        {
          strcpy (OutRecord->ErrorMessage, "Destination address not resolved.");
          OutRecord->Fatal = 1;
          return (0);
        }

      if (Address.Constant && !Address.Address)
        {
          if (Address.Value < 01400)
            {
              // Unswitched erasable.
              Address.Constant = 0;
              Address.Address = 1;
              Address.Erasable = 1;
              Address.Banked = 0;
              Address.SReg = Address.Value;
            }
          else if (Address.Value < 04000)
            {
              // Switched erasable.
              Address.Constant = 0;
              Address.Address = 1;
              Address.Erasable = 1;
              Address.Banked = 1;
              Address.EB = Address.Value / 0400;
              Address.SReg = (Address.Value % 0400) + 01400;
            }
        }

      if (!Address.Address)
        {
          strcpy (OutRecord->ErrorMessage, "Destination is not a memory address.");
          OutRecord->Fatal = 1;
          return (0);
        }

      if (!Address.Erasable)
        {
          strcpy (OutRecord->ErrorMessage, "Destination not in erasable memory.");
          OutRecord->Fatal = 1;
          return (0);
        }

      if (Address.Value < 0 || Address.Value > 03777)
        {
          strcpy (OutRecord->ErrorMessage, "Destination address out of range.");
          OutRecord->Fatal = 1;
          return (0);
        }

      OutRecord->Words[0] = Address.Value;
    }
  else
    {
      // The operand is NOT a number.  Presumably, it's a symbol.
      i = FetchSymbolPlusOffset(&InRecord->ProgramCounter, InRecord->Operand, InRecord->Mod1, &Address);
      if (!i)
        goto DoIt;

      sprintf(OutRecord->ErrorMessage, "Symbol \"%s\" undefined or offset bad", InRecord->Operand);
      OutRecord->Fatal = 1;
    }

  return (0);  
}