xref: /dragonfly/usr.bin/window/parser3.c (revision 6e285212)
1 /*
2  * Copyright (c) 1983, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Edward Wang at The University of California, Berkeley.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. 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  * @(#)parser3.c	8.1 (Berkeley) 6/6/93
37  * $FreeBSD: src/usr.bin/window/parser3.c,v 1.1.1.1.14.1 2001/05/17 09:45:00 obrien Exp $
38  * $DragonFly: src/usr.bin/window/parser3.c,v 1.2 2003/06/17 04:29:34 dillon Exp $
39  */
40 
41 #include "parser.h"
42 
43 /*
44  * =
45  * ? :
46  * ||
47  * &&
48  * |
49  * ^
50  * &
51  * == !=
52  * <= >=
53  * << >>
54  * + -
55  * * / %
56  * unary - + ~ !
57  */
58 p_expr(v, flag)
59 register struct value *v;
60 char flag;
61 {
62 	struct value t;
63 	int ret;
64 
65 	if (p_expr0(&t, flag) < 0)
66 		return -1;
67 
68 	if (token != T_ASSIGN) {
69 		*v = t;
70 		return 0;
71 	}
72 	switch (t.v_type) {
73 	case V_NUM:
74 		p_error("%d: Not a variable.", t.v_num);
75 	case V_ERR:
76 		t.v_str = 0;
77 		break;
78 	}
79 	ret = p_assign(t.v_str, v, flag);
80 	if (t.v_str != 0)
81 		str_free(t.v_str);
82 	return ret;
83 }
84 
85 /*
86  * ? :
87  */
88 p_expr0(v, flag)
89 register struct value *v;
90 char flag;
91 {
92 	struct value t;
93 	char true;
94 
95 	if (p_expr1(v, flag) < 0)
96 		return -1;
97 	if (token != T_QUEST)
98 		return 0;
99 	switch (v->v_type) {
100 	case V_NUM:
101 		true = v->v_num != 0;
102 		break;
103 	case V_STR:
104 		p_error("?: Numeric left operand required.");
105 		str_free(v->v_str);
106 		v->v_type = V_ERR;
107 	case V_ERR:
108 		flag = 0;
109 		break;
110 	}
111 	(void) s_gettok();
112 	v->v_type = V_ERR;
113 	if ((flag && true ? p_expr1(v, 1) : p_expr1(&t, 0)) < 0)
114 		return -1;
115 	if (token != T_COLON) {
116 		val_free(*v);
117 		p_synerror();
118 		return -1;
119 	}
120 	(void) s_gettok();
121 	return flag && !true ? p_expr1(v, 1) : p_expr1(&t, 0);
122 }
123 
124 /*
125  * ||
126  */
127 p_expr1(v, flag)
128 register struct value *v;
129 char flag;
130 {
131 	char true = 0;
132 
133 	if (p_expr2(v, flag) < 0)
134 		return -1;
135 	if (token != T_OROR)
136 		return 0;
137 	for (;;) {
138 		switch (v->v_type) {
139 		case V_NUM:
140 			v->v_num = true = true || v->v_num != 0;
141 			break;
142 		case V_STR:
143 			p_error("||: Numeric operands required.");
144 			str_free(v->v_str);
145 			v->v_type = V_ERR;
146 		case V_ERR:
147 			flag = 0;
148 			break;
149 		}
150 		if (token != T_OROR)
151 			return 0;
152 		(void) s_gettok();
153 		if (p_expr2(v, flag && !true) < 0)
154 			return -1;
155 	}
156 }
157 
158 /*
159  * &&
160  */
161 p_expr2(v, flag)
162 register struct value *v;
163 char flag;
164 {
165 	char true = 1;
166 
167 	if (p_expr3_10(3, v, flag) < 0)
168 		return -1;
169 	if (token != T_ANDAND)
170 		return 0;
171 	for (;;) {
172 		switch (v->v_type) {
173 		case V_NUM:
174 			v->v_num = true = true && v->v_num != 0;
175 			break;
176 		case V_STR:
177 			p_error("&&: Numeric operands required.");
178 			str_free(v->v_str);
179 			v->v_type = V_ERR;
180 		case V_ERR:
181 			flag = 0;
182 			break;
183 		}
184 		if (token != T_ANDAND)
185 			return 0;
186 		(void) s_gettok();
187 		if (p_expr3_10(3, v, flag && true) < 0)
188 			return -1;
189 	}
190 	/*NOTREACHED*/
191 }
192