db_variables.c revision 131952
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 131952 2004-07-10 23:47:20Z marcel $"); 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}; 49static struct db_variable *db_evars = 50 db_vars + sizeof(db_vars)/sizeof(db_vars[0]); 51 52static int 53db_find_variable(struct db_variable **varp) 54{ 55 struct db_variable *vp; 56 int t; 57 58 t = db_read_token(); 59 if (t == tIDENT) { 60 for (vp = db_vars; vp < db_evars; vp++) { 61 if (!strcmp(db_tok_string, vp->name)) { 62 *varp = vp; 63 return (1); 64 } 65 } 66 for (vp = db_regs; vp < db_eregs; vp++) { 67 if (!strcmp(db_tok_string, vp->name)) { 68 *varp = vp; 69 return (1); 70 } 71 } 72 } 73 db_error("Unknown variable\n"); 74 return (0); 75} 76 77int 78db_get_variable(db_expr_t *valuep) 79{ 80 struct db_variable *vp; 81 82 if (!db_find_variable(&vp)) 83 return (0); 84 85 return (db_read_variable(vp, valuep)); 86} 87 88int 89db_set_variable(db_expr_t value) 90{ 91 struct db_variable *vp; 92 93 if (!db_find_variable(&vp)) 94 return (0); 95 96 return (db_write_variable(vp, value)); 97} 98 99int 100db_read_variable(struct db_variable *vp, db_expr_t *valuep) 101{ 102 db_varfcn_t *func = vp->fcn; 103 104 if (func == FCN_NULL) { 105 *valuep = *(vp->valuep); 106 return (1); 107 } 108 return ((*func)(vp, valuep, DB_VAR_GET)); 109} 110 111int 112db_write_variable(struct db_variable *vp, db_expr_t value) 113{ 114 db_varfcn_t *func = vp->fcn; 115 116 if (func == FCN_NULL) { 117 *(vp->valuep) = value; 118 return (1); 119 } 120 return ((*func)(vp, &value, DB_VAR_SET)); 121} 122 123void 124db_set_cmd(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4) 125{ 126 struct db_variable *vp; 127 db_expr_t value; 128 int t; 129 130 t = db_read_token(); 131 if (t != tDOLLAR) { 132 db_error("Unknown variable\n"); 133 return; 134 } 135 if (!db_find_variable(&vp)) { 136 db_error("Unknown variable\n"); 137 return; 138 } 139 140 t = db_read_token(); 141 if (t != tEQ) 142 db_unread_token(t); 143 144 if (!db_expression(&value)) { 145 db_error("No value\n"); 146 return; 147 } 148 if (db_read_token() != tEOL) 149 db_error("?\n"); 150 151 db_write_variable(vp, value); 152} 153