1 %{
2 /* $NetBSD: arith.y,v 1.17 2003/09/17 17:33:36 jmmv Exp $ */
3
4 /*-
5 * Copyright (c) 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 * Kenneth Almquist.
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 <sys/cdefs.h>
37 #ifndef lint
38 #if 0
39 static char sccsid[] = "@(#)arith.y 8.3 (Berkeley) 5/4/95";
40 #else
41 __RCSID("$NetBSD: arith.y,v 1.17 2003/09/17 17:33:36 jmmv Exp $");
42 #endif
43 #endif /* not lint */
44
45 #include <stdlib.h>
46 #include "expand.h"
47 #include "shell.h"
48 #include "error.h"
49 #include "output.h"
50 #include "memalloc.h"
51
52 const char *arith_buf, *arith_startbuf;
53
54 void yyerror(const char *);
55 #ifdef TESTARITH
56 int main(int , char *[]);
57 int error(char *);
58 #endif
59
60 %}
61 %token ARITH_NUM ARITH_LPAREN ARITH_RPAREN
62
63 %left ARITH_OR
64 %left ARITH_AND
65 %left ARITH_BOR
66 %left ARITH_BXOR
67 %left ARITH_BAND
68 %left ARITH_EQ ARITH_NE
69 %left ARITH_LT ARITH_GT ARITH_GE ARITH_LE
70 %left ARITH_LSHIFT ARITH_RSHIFT
71 %left ARITH_ADD ARITH_SUB
72 %left ARITH_MUL ARITH_DIV ARITH_REM
73 %left ARITH_UNARYMINUS ARITH_UNARYPLUS ARITH_NOT ARITH_BNOT
74 %%
75
76 exp: expr {
77 return ($1);
78 }
79 ;
80
81
82 expr: ARITH_LPAREN expr ARITH_RPAREN { $$ = $2; }
83 | expr ARITH_OR expr { $$ = $1 ? $1 : $3 ? $3 : 0; }
84 | expr ARITH_AND expr { $$ = $1 ? ( $3 ? $3 : 0 ) : 0; }
85 | expr ARITH_BOR expr { $$ = $1 | $3; }
86 | expr ARITH_BXOR expr { $$ = $1 ^ $3; }
87 | expr ARITH_BAND expr { $$ = $1 & $3; }
88 | expr ARITH_EQ expr { $$ = $1 == $3; }
89 | expr ARITH_GT expr { $$ = $1 > $3; }
90 | expr ARITH_GE expr { $$ = $1 >= $3; }
91 | expr ARITH_LT expr { $$ = $1 < $3; }
92 | expr ARITH_LE expr { $$ = $1 <= $3; }
93 | expr ARITH_NE expr { $$ = $1 != $3; }
94 | expr ARITH_LSHIFT expr { $$ = $1 << $3; }
95 | expr ARITH_RSHIFT expr { $$ = $1 >> $3; }
96 | expr ARITH_ADD expr { $$ = $1 + $3; }
97 | expr ARITH_SUB expr { $$ = $1 - $3; }
98 | expr ARITH_MUL expr { $$ = $1 * $3; }
99 | expr ARITH_DIV expr {
100 if ($3 == 0)
101 yyerror("division by zero");
102 $$ = $1 / $3;
103 }
104 | expr ARITH_REM expr {
105 if ($3 == 0)
106 yyerror("division by zero");
107 $$ = $1 % $3;
108 }
109 | ARITH_NOT expr { $$ = !($2); }
110 | ARITH_BNOT expr { $$ = ~($2); }
111 | ARITH_SUB expr %prec ARITH_UNARYMINUS { $$ = -($2); }
112 | ARITH_ADD expr %prec ARITH_UNARYPLUS { $$ = $2; }
113 | ARITH_NUM
114 ;
115 %%
116 int
arith(s)117 arith(s)
118 const char *s;
119 {
120 long result;
121
122 arith_buf = arith_startbuf = s;
123
124 INTOFF;
125 result = yyparse();
126 arith_lex_reset(); /* reprime lex */
127 INTON;
128
129 return (result);
130 }
131
132
133 /*
134 * The exp(1) builtin.
135 */
136 int
expcmd(argc,argv)137 expcmd(argc, argv)
138 int argc;
139 char **argv;
140 {
141 const char *p;
142 char *concat;
143 char **ap;
144 long i;
145
146 if (argc > 1) {
147 p = argv[1];
148 if (argc > 2) {
149 /*
150 * concatenate arguments
151 */
152 STARTSTACKSTR(concat);
153 ap = argv + 2;
154 for (;;) {
155 while (*p)
156 STPUTC(*p++, concat);
157 if ((p = *ap++) == NULL)
158 break;
159 STPUTC(' ', concat);
160 }
161 STPUTC('\0', concat);
162 p = grabstackstr(concat);
163 }
164 } else
165 p = "";
166
167 i = arith(p);
168
169 out1fmt("%ld\n", i);
170 return (! i);
171 }
172
173 /*************************/
174 #ifdef TEST_ARITH
175 #include <stdio.h>
main(argc,argv)176 main(argc, argv)
177 char *argv[];
178 {
179 printf("%d\n", exp(argv[1]));
180 }
error(s)181 error(s)
182 char *s;
183 {
184 fprintf(stderr, "exp: %s\n", s);
185 exit(1);
186 }
187 #endif
188
189 void
yyerror(s)190 yyerror(s)
191 const char *s;
192 {
193
194 // yyerrok;
195 yyclearin;
196 arith_lex_reset(); /* reprime lex */
197 error("arithmetic expression: %s: \"%s\"", s, arith_startbuf);
198 /* NOTREACHED */
199 }
200