arith_token.c revision 1.4
1 /* $NetBSD: arith_token.c,v 1.4 2017/05/29 22:54:07 kre Exp $ */ 2 3 /*- 4 * Copyright (c) 2002 5 * Herbert Xu. 6 * Copyright (c) 1991, 1993 7 * The Regents of the University of California. All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * Kenneth Almquist. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * From FreeBSD, from dash 37 */ 38 39 #include <sys/cdefs.h> 40 41 #ifndef lint 42 __RCSID("$NetBSD: arith_token.c,v 1.4 2017/05/29 22:54:07 kre Exp $"); 43 #endif /* not lint */ 44 45 #include <inttypes.h> 46 #include <limits.h> 47 #include <stdlib.h> 48 #include <string.h> 49 50 #include "shell.h" 51 #include "arith_tokens.h" 52 #include "expand.h" 53 #include "error.h" 54 #include "memalloc.h" 55 #include "parser.h" 56 #include "syntax.h" 57 #include "show.h" 58 59 #if ARITH_BOR + ARITH_ASS_GAP != ARITH_BORASS || \ 60 ARITH_ASS + ARITH_ASS_GAP != ARITH_EQ 61 #error Arithmetic tokens are out of order. 62 #endif 63 64 /* 65 * Scan next arithmetic token, return its type, 66 * leave its value (when applicable) in (global) a_t_val. 67 * 68 * Input text is in (global) arith_buf which is updated to 69 * refer to the next char after the token returned, except 70 * on error (ARITH_BAD returned) where arith_buf is not altered. 71 */ 72 int 73 arith_token(void) 74 { 75 int token; 76 const char *buf = arith_buf; 77 char *end; 78 const char *p; 79 80 for (;;) { 81 token = *buf; 82 83 if (isdigit(token)) { 84 /* 85 * Numbers all start with a digit, and nothing 86 * else does, the number ends wherever 87 * strtoimax() stops... 88 */ 89 a_t_val.val = strtoimax(buf, &end, 0); 90 arith_buf = end; 91 VTRACE(DBG_ARITH, ("Arith token ARITH_NUM=%jd\n", 92 a_t_val.val)); 93 return ARITH_NUM; 94 95 } else if (is_name(token)) { 96 /* 97 * Variable names all start with an alpha (or '_') 98 * and nothing else does. They continue for the 99 * longest unbroken sequence of alphanumerics ( + _ ) 100 */ 101 p = buf; 102 while (buf++, is_in_name(*buf)) 103 ; 104 a_t_val.name = stalloc(buf - p + 1); 105 memcpy(a_t_val.name, p, buf - p); 106 a_t_val.name[buf - p] = '\0'; 107 arith_buf = buf; 108 VTRACE(DBG_ARITH, ("Arith token ARITH_VAR=\"%s\"\n", 109 a_t_val.name)); 110 return ARITH_VAR; 111 112 } else switch (token) { 113 /* 114 * everything else must be some kind of 115 * operator, white space, or an error. 116 */ 117 case '\n': 118 VTRACE(DBG_ARITH, ("Arith: newline\n")); 119 /* FALLTHROUGH */ 120 case ' ': 121 case '\t': 122 buf++; 123 continue; 124 125 default: 126 error("arithmetic: unexpected '%c' (%#x) in expression", 127 token, token); 128 /* NOTREACHED */ 129 130 case '=': 131 token = ARITH_ASS; 132 checkeq: 133 buf++; 134 checkeqcur: 135 if (*buf != '=') 136 goto out; 137 token += ARITH_ASS_GAP; 138 break; 139 140 case '>': 141 switch (*++buf) { 142 case '=': 143 token = ARITH_GE; 144 break; 145 case '>': 146 token = ARITH_RSHIFT; 147 goto checkeq; 148 default: 149 token = ARITH_GT; 150 goto out; 151 } 152 break; 153 154 case '<': 155 switch (*++buf) { 156 case '=': 157 token = ARITH_LE; 158 break; 159 case '<': 160 token = ARITH_LSHIFT; 161 goto checkeq; 162 default: 163 token = ARITH_LT; 164 goto out; 165 } 166 break; 167 168 case '|': 169 if (*++buf != '|') { 170 token = ARITH_BOR; 171 goto checkeqcur; 172 } 173 token = ARITH_OR; 174 break; 175 176 case '&': 177 if (*++buf != '&') { 178 token = ARITH_BAND; 179 goto checkeqcur; 180 } 181 token = ARITH_AND; 182 break; 183 184 case '!': 185 if (*++buf != '=') { 186 token = ARITH_NOT; 187 goto out; 188 } 189 token = ARITH_NE; 190 break; 191 192 case 0: 193 goto out; 194 195 case '(': 196 token = ARITH_LPAREN; 197 break; 198 case ')': 199 token = ARITH_RPAREN; 200 break; 201 202 case '*': 203 token = ARITH_MUL; 204 goto checkeq; 205 case '/': 206 token = ARITH_DIV; 207 goto checkeq; 208 case '%': 209 token = ARITH_REM; 210 goto checkeq; 211 212 case '+': 213 if (buf[1] == '+') 214 error("arithmetic: ++ operator unsupported"); 215 token = ARITH_ADD; 216 goto checkeq; 217 case '-': 218 if (buf[1] == '-') 219 error("arithmetic: -- operator unsupported"); 220 token = ARITH_SUB; 221 goto checkeq; 222 case '~': 223 token = ARITH_BNOT; 224 break; 225 case '^': 226 token = ARITH_BXOR; 227 goto checkeq; 228 229 case '?': 230 token = ARITH_QMARK; 231 break; 232 case ':': 233 token = ARITH_COLON; 234 break; 235 } 236 break; 237 } 238 buf++; 239 out: 240 arith_buf = buf; 241 VTRACE(DBG_ARITH, ("Arith token: %d\n", token)); 242 return token; 243 } 244
Indexes created Thu Sep 25 16:09:42 GMT 2025