1 /*	$OpenBSD: parser5.c,v 1.5 2003/06/03 02:56:23 millert Exp $	*/
2 /*	$NetBSD: parser5.c,v 1.3 1995/09/28 10:34:35 tls 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 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)parser5.c	8.1 (Berkeley) 6/6/93";
39 #else
40 static char rcsid[] = "$OpenBSD: parser5.c,v 1.5 2003/06/03 02:56:23 millert Exp $";
41 #endif
42 #endif /* not lint */
43 
44 #include "parser.h"
45 #include "var.h"
46 
47 /*
48  * unary $ $? + - ! ~
49  */
50 p_expr11(v, flag)
51 struct value *v;
52 char flag;
53 {
54 	int op;
55 	char *opname;
56 
57 	switch (token) {
58 	case T_DOLLAR:
59 		opname = "$";
60 		break;
61 	case T_DQ:
62 		opname = "$?";
63 		break;
64 	case T_PLUS:
65 		opname = "unary +";
66 		break;
67 	case T_MINUS:
68 		opname = "unary -";
69 		break;
70 	case T_NOT:
71 		opname = "!";
72 		break;
73 	case T_COMP:
74 		opname = "~";
75 		break;
76 	default:
77 		return p_expr12(v, flag);
78 	}
79 	op = token;
80 	(void) s_gettok();
81 	if (p_expr11(v, flag) < 0)
82 		return -1;
83 	switch (v->v_type) {
84 	case V_NUM:
85 		break;
86 	case V_STR:
87 		switch (op) {
88 		case T_MINUS:
89 		case T_NOT:
90 		case T_COMP:
91 			p_error("%s: Numeric operand required.", opname);
92 			str_free(v->v_str);
93 			v->v_type = V_ERR;
94 			return 0;
95 		}
96 		break;
97 	case V_ERR:
98 		return 0;
99 	}
100 	switch (op) {
101 	case T_DOLLAR:
102 	case T_DQ:
103 		if (v->v_type == V_NUM) {
104 			int tmp = cx.x_type == X_BUF && cx.x_arg != 0 &&
105 				v->v_num > 0 && v->v_num <= cx.x_narg;
106 			if (op == T_DQ)
107 				v->v_num = tmp;
108 			else if (tmp)
109 				*v = cx.x_arg[v->v_num - 1];
110 			else {
111 				p_error("%d: No such argument.", v->v_num);
112 				v->v_type = V_ERR;
113 			}
114 		} else {
115 			char *name = v->v_str;
116 			struct var *r = var_lookup(name);
117 			if (op == T_DQ) {
118 				v->v_type = V_NUM;
119 				v->v_num = r != 0;
120 			} else if (r != 0)
121 				*v = r->r_val;
122 			else {
123 				p_error("%s: Undefined variable.", name);
124 				v->v_type = V_ERR;
125 			}
126 			str_free(name);
127 		}
128 		if (v->v_type == V_STR && (v->v_str = str_cpy(v->v_str)) == 0) {
129 			p_memerror();
130 			return -1;
131 		}
132 		break;
133 	case T_MINUS:
134 		v->v_num = - v->v_num;
135 		break;
136 	case T_NOT:
137 		v->v_num = ! v->v_num;
138 		break;
139 	case T_COMP:
140 		v->v_num = ~ v->v_num;
141 		break;
142 	}
143 	return 0;
144 }
145 
146 /*
147  * string, number, ( expr )
148  * Plus function calls.
149  *
150  * Always return v_type == V_ERR when flag == 0.
151  */
152 p_expr12(v, flag)
153 struct value *v;
154 char flag;
155 {
156 	v->v_type = V_ERR;
157 	switch (token) {
158 	case T_NUM:
159 		if (flag) {
160 			v->v_type = V_NUM;
161 			v->v_num = token_num;
162 		}
163 		(void) s_gettok();
164 		break;
165 	case T_STR:
166 		if (flag) {
167 			v->v_type = V_STR;
168 			v->v_str = token_str;
169 		} else
170 			str_free(token_str);
171 		(void) s_gettok();
172 		break;
173 	case T_LP:
174 		(void) s_gettok();
175 		if (p_expr(v, flag) < 0) {
176 			p_synerror();
177 			return -1;
178 		}
179 		if (token != T_RP) {
180 			p_synerror();
181 			val_free(*v);
182 			return -1;
183 		}
184 		(void) s_gettok();
185 		break;
186 	default:
187 		return -1;
188 	}
189 	while (token == T_LP) {
190 		char *cmd;
191 
192 		if (p_convstr(v) < 0)
193 			return -1;
194 		cmd = v->v_type == V_STR ? v->v_str : 0;
195 		if (p_function(cmd, v, flag) < 0) {
196 			if (cmd)
197 				str_free(cmd);
198 			return -1;
199 		}
200 		if (cmd)
201 			str_free(cmd);
202 	}
203 	return 0;
204 }
205