1 /* @(#)parser1.c 8.1 (Berkeley) 6/6/93 */
2 /* $NetBSD: parser1.c,v 1.6 2003/08/07 11:17:28 agc 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 #include "defs.h"
37 #include "parser.h"
38
39 void
p_start(void)40 p_start(void)
41 {
42 char flag = 1;
43
44 (void) s_gettok();
45 for (;;) {
46 p_statementlist(flag);
47 if (token == T_EOF || p_abort())
48 break;
49 flag = 0;
50 p_synerror();
51 while (token != T_EOL && token != T_EOF) {
52 if (token == T_STR)
53 str_free(token_str);
54 (void) s_gettok();
55 }
56 if (token == T_EOL)
57 (void) s_gettok();
58 p_clearerr();
59 }
60 }
61
62 void
p_statementlist(char flag)63 p_statementlist(char flag)
64 {
65 for (; p_statement(flag) >= 0; p_clearerr())
66 ;
67 }
68
69 int
p_statement(char flag)70 p_statement(char flag)
71 {
72 switch (token) {
73 case T_EOL:
74 (void) s_gettok();
75 return 0;
76 case T_IF:
77 return p_if(flag);
78 default:
79 return p_expression(flag);
80 }
81 }
82
83 int
p_if(char flag)84 p_if(char flag)
85 {
86 struct value t;
87 char true = 0;
88
89 top:
90 (void) s_gettok();
91
92 if (p_expr(&t, flag) < 0) {
93 p_synerror();
94 return -1;
95 }
96 switch (t.v_type) {
97 case V_NUM:
98 true = !true && t.v_num != 0;
99 break;
100 case V_STR:
101 p_error("if: Numeric value required.");
102 str_free(t.v_str);
103 /* FALLTHROUGH */
104 case V_ERR:
105 flag = 0;
106 break;
107 }
108
109 if (token != T_THEN) {
110 p_synerror();
111 return -1;
112 }
113
114 (void) s_gettok();
115 p_statementlist(flag && true);
116 if (p_erred())
117 return -1;
118
119 if (token == T_ELSIF)
120 goto top;
121
122 if (token == T_ELSE) {
123 (void) s_gettok();
124 p_statementlist(flag && !true);
125 if (p_erred())
126 return -1;
127 }
128
129 if (token == T_ENDIF) {
130 (void) s_gettok();
131 return 0;
132 }
133
134 p_synerror();
135 return -1;
136 }
137
138 int
p_expression(char flag)139 p_expression(char flag)
140 {
141 struct value t;
142 char *cmd;
143
144 switch (token) {
145 case T_NUM:
146 t.v_type = V_NUM;
147 t.v_num = token_num;
148 (void) s_gettok();
149 break;
150 case T_STR:
151 t.v_type = V_STR;
152 t.v_str = token_str;
153 (void) s_gettok();
154 break;
155 default:
156 if (p_expr(&t, flag) < 0)
157 return -1;
158 if (token == T_EOF) {
159 val_free(t);
160 return 0;
161 }
162 }
163 if (token != T_ASSIGN && p_convstr(&t) < 0)
164 return -1;
165 cmd = t.v_type == V_STR ? t.v_str : 0;
166 if ((*(token == T_ASSIGN ? p_assign : p_function))(cmd, &t, flag) < 0) {
167 if (cmd)
168 str_free(cmd);
169 return -1;
170 }
171 if (cmd)
172 str_free(cmd);
173 val_free(t);
174 if (token == T_EOL)
175 (void) s_gettok();
176 else if (token != T_EOF) {
177 p_synerror();
178 return -1;
179 }
180 return 0;
181 }
182
183 int
p_convstr(struct value * v)184 p_convstr(struct value *v)
185 {
186 if (v->v_type != V_NUM)
187 return 0;
188 if ((v->v_str = str_itoa(v->v_num)) == 0) {
189 p_memerror();
190 v->v_type = V_ERR;
191 return -1;
192 }
193 v->v_type = V_STR;
194 return 0;
195 }
196
197 void
p_synerror(void)198 p_synerror(void)
199 {
200 if (!cx.x_synerred) {
201 cx.x_synerred = cx.x_erred = 1;
202 error("Syntax error.");
203 }
204 }
205
206 void
p_error(const char * msg,...)207 p_error(const char *msg, ...)
208 {
209 va_list ap;
210
211 va_start(ap, msg);
212 if (!cx.x_erred) {
213 cx.x_erred = 1;
214 verror(msg, ap);
215 }
216 va_end(ap);
217 }
218
219 void
p_memerror(void)220 p_memerror(void)
221 {
222 cx.x_erred = cx.x_abort = 1;
223 error("Out of memory.");
224 }
225