sys/ddb/db_variables.c

   1 /*
   2  * Mach Operating System
   3  * Copyright (c) 1991,1990 Carnegie Mellon University
   4  * All Rights Reserved.
   5  *
   6  * Permission to use, copy, modify and distribute this software and its
   7  * documentation is hereby granted, provided that both the copyright
   8  * notice and this permission notice appear in all copies of the
   9  * software, derivative works or modified versions, and any portions
  10  * thereof, and that both notices appear in supporting documentation.
  11  *
  12  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
  13  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  14  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  15  *
  16  * Carnegie Mellon requests users of this software to return to
  17  *
  18  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  19  *  School of Computer Science
  20  *  Carnegie Mellon University
  21  *  Pittsburgh PA 15213-3890
  22  *
  23  * any improvements or extensions that they make and grant Carnegie the
  24  * rights to redistribute these changes.
  25  *
  26  * $FreeBSD: src/sys/ddb/db_variables.c,v 1.18 1999/08/28 00:41:11 peter Exp $
  27  * $DragonFly: src/sys/ddb/db_variables.c,v 1.4 2005/12/23 21:35:44 swildner Exp $
  28  */
  29
  30 /*
  31  *      Author: David B. Golub, Carnegie Mellon University
  32  *      Date:   7/90
  33  */
  34
  35 #include <sys/param.h>
  36 #include <sys/systm.h>
  37
  38 #include <ddb/ddb.h>
  39 #include <ddb/db_lex.h>
  40 #include <ddb/db_variables.h>
  41
  42 static int      db_find_variable (struct db_variable **varp);
  43 static void     db_write_variable (struct db_variable *, db_expr_t *);
  44
  45 #ifdef notused
  46 static int      db_set_variable (db_expr_t value);
  47 #endif
  48
  49 static struct db_variable db_vars[] = {
  50         { "radix",      &db_radix, NULL },
  51         { "maxoff",     &db_maxoff, NULL },
  52         { "maxwidth",   &db_max_width, NULL },
  53         { "tabstops",   &db_tab_stop_width, NULL },
  54 };
  55 static struct db_variable *db_evars =
  56                 db_vars + sizeof(db_vars)/sizeof(db_vars[0]);
  57
  58 static int
  59 db_find_variable(struct db_variable **varp)
  60 {
  61         int     t;
  62         struct db_variable *vp;
  63
  64         t = db_read_token();
  65         if (t == tIDENT) {
  66             for (vp = db_vars; vp < db_evars; vp++) {
  67                 if (!strcmp(db_tok_string, vp->name)) {
  68                     *varp = vp;
  69                     return (1);
  70                 }
  71             }
  72             for (vp = db_regs; vp < db_eregs; vp++) {
  73                 if (!strcmp(db_tok_string, vp->name)) {
  74                     *varp = vp;
  75                     return (1);
  76                 }
  77             }
  78         }
  79         db_error("Unknown variable\n");
  80         return (0);
  81 }
  82
  83 int
  84 db_get_variable(db_expr_t *valuep)
  85 {
  86         struct db_variable *vp;
  87
  88         if (!db_find_variable(&vp))
  89             return (0);
  90
  91         db_read_variable(vp, valuep);
  92
  93         return (1);
  94 }
  95
  96 #ifdef notused
  97 static int
  98 db_set_variable(db_expr_t value)
  99 {
 100         struct db_variable *vp;
 101
 102         if (!db_find_variable(&vp))
 103             return (0);
 104
 105         db_write_variable(vp, &value);
 106
 107         return (1);
 108 }
 109 #endif
 110
 111 void
 112 db_read_variable(struct db_variable *vp, db_expr_t *valuep)
 113 {
 114         db_varfcn_t     *func = vp->fcn;
 115
 116         if (func == NULL)
 117             *valuep = *(vp->valuep);
 118         else
 119             (*func)(vp, valuep, DB_VAR_GET);
 120 }
 121
 122 static void
 123 db_write_variable(struct db_variable *vp, db_expr_t *valuep)
 124 {
 125         db_varfcn_t     *func = vp->fcn;
 126
 127         if (func == NULL)
 128             *(vp->valuep) = *valuep;
 129         else
 130             (*func)(vp, valuep, DB_VAR_SET);
 131 }
 132
 133 void
 134 db_set_cmd(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
 135 {
 136         db_expr_t       value;
 137         struct db_variable *vp;
 138         int     t;
 139
 140         t = db_read_token();
 141         if (t != tDOLLAR) {
 142             db_error("Unknown variable\n");
 143             return;
 144         }
 145         if (!db_find_variable(&vp)) {
 146             db_error("Unknown variable\n");
 147             return;
 148         }
 149
 150         t = db_read_token();
 151         if (t != tEQ)
 152             db_unread_token(t);
 153
 154         if (!db_expression(&value)) {
 155             db_error("No value\n");
 156             return;
 157         }
 158         if (db_read_token() != tEOL) {
 159             db_error("?\n");
 160         }
 161
 162         db_write_variable(vp, &value);
 163 }