/* This software is Copyright 1989, 1990, 1992, 1993 by various individuals.
   Please see the accompanying file COPYRIGHT for details. */

#include "db.h"
#include "inst.h"
#include "config.h"
#include "externs.h"
#include "interface.h"

void disassemble(dbref player, dbref program, int oarg[], int argc)
{
 struct inst *curr;
 struct inst *codestart;
 struct inst *start;
 int i;
 int o1;
 int o2;
 struct stab *stab;
 int nstab;
 int stabx;
 char *bp;
 char buf[BUFFER_LEN];

 codestart = DBFETCH(program)->sp.program.codevec;
 if (!DBFETCH(program)->sp.program.codesiz)
  { notify(player,"Nothing to disassemble!");
    return;
  }
 if ((argc != 0) && (argc != 2))
  { notify(player,"You must provide zero or two offset arguments!");
    return;
  }
 if (argc)
  { int csz;
    o1 = oarg[0];
    o2 = oarg[1];
    if (o1 < 0)
     { notify(player,"Invalid argument: start offset must be >= 0");
       return;
     }
    if (o2 < o1)
     { notify(player,"Invalid argument: end must be >= start");
       return;
     }
    csz = DBFETCH(program)->sp.program.codesiz;
    if (o1 >= csz)
     { sprintf(&buf[0],"Program ends at %d",csz-1);
       notify(player,&buf[0]);
       return;
     }
    if (o2 >= csz)
     { o2 = csz - 1;
       sprintf(&buf[0],"Note: program ends at %d",o2);
       notify(player,&buf[0]);
     }
  }
 else
  { o1 = 0;
    o2 = DBFETCH(program)->sp.program.codesiz - 1;
  }
 stab = DBFETCH(program)->sp.program.stabvec;
 nstab = DBFETCH(program)->sp.program.stabsiz;
 start = DBFETCH(program)->sp.program.start;
 stabx = 0;
 curr = codestart + o1;
 for (i=o1;i<=o2;i++,curr++)
  { bp = &buf[0];
    while ((stabx+1 < nstab) && (stab[stabx+1].off <= i)) stabx ++;
    sprintf(bp,"%3d%c %s+%d: ",i,(curr==start)?'*':':',stab[stabx].name,i-stab[stabx].off);
    bp += strlen(bp);
    switch (curr->type)
     { case PROG_PRIMITIVE:
	  if ((curr->data.number >= BASE_MIN) && (curr->data.number <= BASE_MAX))
	   { sprintf(bp,"PRIMITIVE: %s",base_inst[curr->data.number-BASE_MIN]);
	   }
	  else
	   { sprintf(bp,"PRIMITIVE: %d",curr->data.number);
	   }
	  break;
       case PROG_STRING:
	  sprintf(bp,"STRING: \"%s\"",curr->data.string?curr->data.string:"");
	  break;
       case PROG_INTEGER:
	  sprintf(bp,"INTEGER: %d",curr->data.number);
	  break;
       case PROG_ADD:
	   { struct stab *st;
	     sprintf(bp,"ADDRESS: %d",(int)(curr->data.call-codestart));
	     st = findstab(program,curr->data.call-codestart);
	     if (st)
	      { bp += strlen(bp);
		sprintf(bp," (%s+%d)",st->name,(int)(curr->data.call-codestart)-st->off);
	      }
	   }
	  break;
       case PROG_OBJECT:
	  sprintf(bp,"OBJECT REF: %d",curr->data.number);
	  break;
       case PROG_VAR:
	  sprintf(bp,"VARIABLE: %d",curr->data.number);
	  break;
       case PROG_PTR:
	  if (Typeof(curr->data.ptr->prog) == TYPE_PROGRAM)
	   { if (DBFETCH(curr->data.ptr->prog)->sp.program.start == 0)
	      { sprintf(bp,"POINTER: <#%d,uncompiled>",curr->data.ptr->prog);
	      }
	     else
	      { struct stab *st;
		sprintf(bp,"POINTER: <#%d,%d>",curr->data.ptr->prog,(int)(curr->data.ptr->ptr-DBFETCH(curr->data.ptr->prog)->sp.program.codevec));
		st = findstab(curr->data.ptr->prog,curr->data.ptr->ptr-DBFETCH(curr->data.ptr->prog)->sp.program.codevec);
		if (st)
		 { bp += strlen(bp);
		   sprintf(bp," (%s+%d)",st->name,(int)(curr->data.ptr->ptr-DBFETCH(curr->data.ptr->prog)->sp.program.codevec)-st->off);
		 }
	      }
	   }
	  else
	   { sprintf(bp,"POINTER: <#%d,non-program>",curr->data.ptr->prog);
	   }
	  break;
       case PROG_RE:
	  sprintf(bp,"REGEXP (?)");
	  break;
     }
    notify(player,&buf[0]);
  }
}