db_variables.c revision 137117
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/* 27 * Author: David B. Golub, Carnegie Mellon University 28 * Date: 7/90 29 */ 30 31#include <sys/cdefs.h> 32__FBSDID("$FreeBSD: head/sys/ddb/db_variables.c 137117 2004-11-01 22:15:15Z jhb $"); 33 34#include <sys/param.h> 35#include <sys/systm.h> 36 37#include <ddb/ddb.h> 38#include <ddb/db_lex.h> 39#include <ddb/db_variables.h> 40 41static int db_find_variable(struct db_variable **varp); 42 43static struct db_variable db_vars[] = { 44 { "radix", &db_radix, FCN_NULL }, 45 { "maxoff", &db_maxoff, FCN_NULL }, 46 { "maxwidth", &db_max_width, FCN_NULL }, 47 { "tabstops", &db_tab_stop_width, FCN_NULL }, 48 { "lines", &db_lines_per_page, FCN_NULL }, 49}; 50static struct db_variable *db_evars = 51 db_vars + sizeof(db_vars)/sizeof(db_vars[0]); 52 53static int 54db_find_variable(struct db_variable **varp) 55{ 56 struct db_variable *vp; 57 int t; 58 59 t = db_read_token(); 60 if (t == tIDENT) { 61 for (vp = db_vars; vp < db_evars; vp++) { 62 if (!strcmp(db_tok_string, vp->name)) { 63 *varp = vp; 64 return (1); 65 } 66 } 67 for (vp = db_regs; vp < db_eregs; vp++) { 68 if (!strcmp(db_tok_string, vp->name)) { 69 *varp = vp; 70 return (1); 71 } 72 } 73 } 74 db_error("Unknown variable\n"); 75 return (0); 76} 77 78int 79db_get_variable(db_expr_t *valuep) 80{ 81 struct db_variable *vp; 82 83 if (!db_find_variable(&vp)) 84 return (0); 85 86 return (db_read_variable(vp, valuep)); 87} 88 89int 90db_set_variable(db_expr_t value) 91{ 92 struct db_variable *vp; 93 94 if (!db_find_variable(&vp)) 95 return (0); 96 97 return (db_write_variable(vp, value)); 98} 99 100int 101db_read_variable(struct db_variable *vp, db_expr_t *valuep) 102{ 103 db_varfcn_t *func = vp->fcn; 104 105 if (func == FCN_NULL) { 106 *valuep = *(vp->valuep); 107 return (1); 108 } 109 return ((*func)(vp, valuep, DB_VAR_GET)); 110} 111 112int 113db_write_variable(struct db_variable *vp, db_expr_t value) 114{ 115 db_varfcn_t *func = vp->fcn; 116 117 if (func == FCN_NULL) { 118 *(vp->valuep) = value; 119 return (1); 120 } 121 return ((*func)(vp, &value, DB_VAR_SET)); 122} 123 124void 125db_set_cmd(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4) 126{ 127 struct db_variable *vp; 128 db_expr_t value; 129 int t; 130 131 t = db_read_token(); 132 if (t != tDOLLAR) { 133 db_error("Unknown variable\n"); 134 return; 135 } 136 if (!db_find_variable(&vp)) { 137 db_error("Unknown variable\n"); 138 return; 139 } 140 141 t = db_read_token(); 142 if (t != tEQ) 143 db_unread_token(t); 144 145 if (!db_expression(&value)) { 146 db_error("No value\n"); 147 return; 148 } 149 if (db_read_token() != tEOL) 150 db_error("?\n"); 151 152 db_write_variable(vp, value); 153} 154