386BSD 0.1 development

[unix-history] / usr / src / sys.386bsd / ddb / db_variables.c

/* 
* Mach Operating System
* Copyright (c) 1991,1990 Carnegie Mellon University
* All Rights Reserved.
* 
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
* 
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS 
* CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
* 
* Carnegie Mellon requests users of this software to return to
* 
*  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
*  School of Computer Science
*  Carnegie Mellon University
*  Pittsburgh PA 15213-3890
* 
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
/*
* HISTORY
* $Log: db_variables.c,v $
* Revision 1.1  1992/03/25  21:45:33  pace
* Initial revision
*
* Revision 2.3  91/02/05  17:07:19  mrt
*      Changed to new Mach copyright
*      [91/01/31  16:19:46  mrt]
* 
* Revision 2.2  90/08/27  21:53:24  dbg
*      New db_read/write_variable functions.  Should be used instead
*      of dereferencing valuep directly, which might not be a true
*      pointer if there is an fcn() access function.
*      [90/08/20            af]
* 
*      Fix declarations.
*      Check for trailing garbage after last expression on command line.
*      [90/08/10  14:34:54  dbg]
* 
*      Created.
*      [90/07/25            dbg]
* 
*/
/*
*      Author: David B. Golub, Carnegie Mellon University
*      Date:   7/90
*/

#include "param.h"
#include "proc.h"
#include <machine/db_machdep.h>

#include <ddb/db_lex.h>
#include <ddb/db_variables.h>

extern unsigned int     db_maxoff;

extern int      db_radix;
extern int      db_max_width;
extern int      db_tab_stop_width;

struct db_variable db_vars[] = {
       { "radix",      &db_radix, FCN_NULL },
       { "maxoff",     (int *)&db_maxoff, FCN_NULL },
       { "maxwidth",   &db_max_width, FCN_NULL },
       { "tabstops",   &db_tab_stop_width, FCN_NULL },
};
struct db_variable *db_evars = db_vars + sizeof(db_vars)/sizeof(db_vars[0]);

int
db_find_variable(varp)
       struct db_variable      **varp;
{
       int     t;
       struct db_variable *vp;

       t = db_read_token();
       if (t == tIDENT) {
           for (vp = db_vars; vp < db_evars; vp++) {
               if (!strcmp(db_tok_string, vp->name)) {
                   *varp = vp;
                   return (1);
               }
           }
           for (vp = db_regs; vp < db_eregs; vp++) {
               if (!strcmp(db_tok_string, vp->name)) {
                   *varp = vp;
                   return (1);
               }
           }
       }
       db_error("Unknown variable\n");
       return (0);
}

int
db_get_variable(valuep)
       db_expr_t       *valuep;
{
       struct db_variable *vp;

       if (!db_find_variable(&vp))
           return (0);

       db_read_variable(vp, valuep);

       return (1);
}

int
db_set_variable(value)
       db_expr_t       value;
{
       struct db_variable *vp;

       if (!db_find_variable(&vp))
           return (0);

       db_write_variable(vp, &value);

       return (1);
}


db_read_variable(vp, valuep)
       struct db_variable *vp;
       db_expr_t       *valuep;
{
       int     (*func)() = vp->fcn;

       if (func == FCN_NULL)
           *valuep = *(vp->valuep);
       else
           (*func)(vp, valuep, DB_VAR_GET);
}

db_write_variable(vp, valuep)
       struct db_variable *vp;
       db_expr_t       *valuep;
{
       int     (*func)() = vp->fcn;

       if (func == FCN_NULL)
           *(vp->valuep) = *valuep;
       else
           (*func)(vp, valuep, DB_VAR_SET);
}

void
db_set_cmd()
{
       db_expr_t       value;
       int     (*func)();
       struct db_variable *vp;
       int     t;

       t = db_read_token();
       if (t != tDOLLAR) {
           db_error("Unknown variable\n");
           return;
       }
       if (!db_find_variable(&vp)) {
           db_error("Unknown variable\n");
           return;
       }

       t = db_read_token();
       if (t != tEQ)
           db_unread_token(t);

       if (!db_expression(&value)) {
           db_error("No value\n");
           return;
       }
       if (db_read_token() != tEOL) {
           db_error("?\n");
       }

       db_write_variable(vp, &value);
}