1 /* @(#)parser3.c 8.1 (Berkeley) 6/6/93 */ 2 /* $NetBSD: parser3.c,v 1.6 2003/08/07 11:17:28 agc Exp $ */ 3 4 /* 5 * Copyright (c) 1983, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Edward Wang at The University of California, Berkeley. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include "defs.h" 37 #include "parser.h" 38 39 /* 40 * = 41 * ? : 42 * || 43 * && 44 * | 45 * ^ 46 * & 47 * == != 48 * <= >= 49 * << >> 50 * + - 51 * * / % 52 * unary - + ~ ! 53 */ 54 int 55 p_expr(struct value *v, char flag) 56 { 57 struct value t; 58 int ret; 59 60 if (p_expr0(&t, flag) < 0) 61 return -1; 62 63 if (token != T_ASSIGN) { 64 *v = t; 65 return 0; 66 } 67 switch (t.v_type) { 68 case V_NUM: 69 p_error("%d: Not a variable.", t.v_num); 70 /* FALLTHROUGH */ 71 case V_ERR: 72 t.v_str = 0; 73 break; 74 } 75 ret = p_assign(t.v_str, v, flag); 76 if (t.v_str != 0) 77 str_free(t.v_str); 78 return ret; 79 } 80 81 /* 82 * ? : 83 */ 84 int 85 p_expr0(struct value *v, char flag) 86 { 87 struct value t; 88 char true = 0; 89 90 if (p_expr1(v, flag) < 0) 91 return -1; 92 if (token != T_QUEST) 93 return 0; 94 switch (v->v_type) { 95 case V_NUM: 96 true = v->v_num != 0; 97 break; 98 case V_STR: 99 p_error("?: Numeric left operand required."); 100 str_free(v->v_str); 101 v->v_type = V_ERR; 102 /* FALLTHROUGH */ 103 case V_ERR: 104 flag = 0; 105 break; 106 } 107 (void) s_gettok(); 108 v->v_type = V_ERR; 109 if ((flag && true ? p_expr1(v, 1) : p_expr1(&t, 0)) < 0) 110 return -1; 111 if (token != T_COLON) { 112 val_free(*v); 113 p_synerror(); 114 return -1; 115 } 116 (void) s_gettok(); 117 return flag && !true ? p_expr1(v, 1) : p_expr1(&t, 0); 118 } 119 120 /* 121 * || 122 */ 123 int 124 p_expr1(struct value *v, char flag) 125 { 126 char true = 0; 127 128 if (p_expr2(v, flag) < 0) 129 return -1; 130 if (token != T_OROR) 131 return 0; 132 for (;;) { 133 switch (v->v_type) { 134 case V_NUM: 135 v->v_num = true = true || v->v_num != 0; 136 break; 137 case V_STR: 138 p_error("||: Numeric operands required."); 139 str_free(v->v_str); 140 v->v_type = V_ERR; 141 /* FALLTHROUGH */ 142 case V_ERR: 143 flag = 0; 144 break; 145 } 146 if (token != T_OROR) 147 return 0; 148 (void) s_gettok(); 149 if (p_expr2(v, flag && !true) < 0) 150 return -1; 151 } 152 } 153 154 /* 155 * && 156 */ 157 int 158 p_expr2(struct value *v, char flag) 159 { 160 char true = 1; 161 162 if (p_expr3_10(3, v, flag) < 0) 163 return -1; 164 if (token != T_ANDAND) 165 return 0; 166 for (;;) { 167 switch (v->v_type) { 168 case V_NUM: 169 v->v_num = true = true && v->v_num != 0; 170 break; 171 case V_STR: 172 p_error("&&: Numeric operands required."); 173 str_free(v->v_str); 174 v->v_type = V_ERR; 175 /* FALLTHROUGH */ 176 case V_ERR: 177 flag = 0; 178 break; 179 } 180 if (token != T_ANDAND) 181 return 0; 182 (void) s_gettok(); 183 if (p_expr3_10(3, v, flag && true) < 0) 184 return -1; 185 } 186 /*NOTREACHED*/ 187 } 188