arith_token.c revision 1.3
1 /* $NetBSD: arith_token.c,v 1.3 2017/03/20 13:12:35 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 1.3 2017/03/20 13:12:35 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 58 #if ARITH_BOR + ARITH_ASS_GAP != ARITH_BORASS || \ 59 ARITH_ASS + ARITH_ASS_GAP != ARITH_EQ 60 #error Arithmetic tokens are out of order. 61 #endif 62 63 /* 64 * Scan next arithmetic token, return its type, 65 * leave its value (when applicable) in (global) a_t_val. 66 * 67 * Input text is in (global) arith_buf which is updated to 68 * refer to the next char after the token returned, except 69 * on error (ARITH_BAD returned) where arith_buf is not altered. 70 */ 71 int 72 arith_token(void) 73 { 74 int token; 75 const char *buf = arith_buf; 76 char *end; 77 const char *p; 78 79 for (;;) { 80 token = *buf; 81 82 if (isdigit(token)) { 83 /* 84 * Numbers all start with a digit, and nothing 85 * else does, the number ends wherever 86 * strtoimax() stops... 87 */ 88 a_t_val.val = strtoimax(buf, &end, 0); 89 arith_buf = end; 90 return ARITH_NUM; 91 92 } else if (is_name(token)) { 93 /* 94 * Variable names all start with an alpha (or '_') 95 * and nothing else does. They continue for the 96 * longest unbroken sequence of alphanumerics ( + _ ) 97 */ 98 p = buf; 99 while (buf++, is_in_name(*buf)) 100 ; 101 a_t_val.name = stalloc(buf - p + 1); 102 memcpy(a_t_val.name, p, buf - p); 103 a_t_val.name[buf - p] = '\0'; 104 arith_buf = buf; 105 return ARITH_VAR; 106 107 } else switch (token) { 108 /* 109 * everything else must be some kind of 110 * operator, white space, or an error. 111 */ 112 case ' ': 113 case '\t': 114 case '\n': 115 buf++; 116 continue; 117 118 default: 119 error("arithmetic: unexpected '%c' (%#x) in expression", 120 token, token); 121 /* NOTREACHED */ 122 123 case '=': 124 token = ARITH_ASS; 125 checkeq: 126 buf++; 127 checkeqcur: 128 if (*buf != '=') 129 goto out; 130 token += ARITH_ASS_GAP; 131 break; 132 133 case '>': 134 switch (*++buf) { 135 case '=': 136 token = ARITH_GE; 137 break; 138 case '>': 139 token = ARITH_RSHIFT; 140 goto checkeq; 141 default: 142 token = ARITH_GT; 143 goto out; 144 } 145 break; 146 147 case '<': 148 switch (*++buf) { 149 case '=': 150 token = ARITH_LE; 151 break; 152 case '<': 153 token = ARITH_LSHIFT; 154 goto checkeq; 155 default: 156 token = ARITH_LT; 157 goto out; 158 } 159 break; 160 161 case '|': 162 if (*++buf != '|') { 163 token = ARITH_BOR; 164 goto checkeqcur; 165 } 166 token = ARITH_OR; 167 break; 168 169 case '&': 170 if (*++buf != '&') { 171 token = ARITH_BAND; 172 goto checkeqcur; 173 } 174 token = ARITH_AND; 175 break; 176 177 case '!': 178 if (*++buf != '=') { 179 token = ARITH_NOT; 180 goto out; 181 } 182 token = ARITH_NE; 183 break; 184 185 case 0: 186 goto out; 187 188 case '(': 189 token = ARITH_LPAREN; 190 break; 191 case ')': 192 token = ARITH_RPAREN; 193 break; 194 195 case '*': 196 token = ARITH_MUL; 197 goto checkeq; 198 case '/': 199 token = ARITH_DIV; 200 goto checkeq; 201 case '%': 202 token = ARITH_REM; 203 goto checkeq; 204 205 case '+': 206 if (buf[1] == '+') 207 error("arithmetic: ++ operator unsupported"); 208 token = ARITH_ADD; 209 goto checkeq; 210 case '-': 211 if (buf[1] == '-') 212 error("arithmetic: -- operator unsupported"); 213 token = ARITH_SUB; 214 goto checkeq; 215 case '~': 216 token = ARITH_BNOT; 217 break; 218 case '^': 219 token = ARITH_BXOR; 220 goto checkeq; 221 222 case '?': 223 token = ARITH_QMARK; 224 break; 225 case ':': 226 token = ARITH_COLON; 227 break; 228 } 229 break; 230 } 231 buf++; 232 out: 233 arith_buf = buf; 234 return token; 235 } 236
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