1 /* $OpenBSD: parser1.c,v 1.5 2003/06/03 02:56:23 millert Exp $ */
2 /* $NetBSD: parser1.c,v 1.3 1995/09/28 10:34:31 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[] = "@(#)parser1.c 8.1 (Berkeley) 6/6/93";
39 #else
40 static char rcsid[] = "$OpenBSD: parser1.c,v 1.5 2003/06/03 02:56:23 millert Exp $";
41 #endif
42 #endif /* not lint */
43
44 #include "parser.h"
45
p_start()46 p_start()
47 {
48 char flag = 1;
49
50 (void) s_gettok();
51 for (;;) {
52 p_statementlist(flag);
53 if (token == T_EOF || p_abort())
54 break;
55 flag = 0;
56 p_synerror();
57 while (token != T_EOL && token != T_EOF) {
58 if (token == T_STR)
59 str_free(token_str);
60 (void) s_gettok();
61 }
62 if (token == T_EOL)
63 (void) s_gettok();
64 p_clearerr();
65 }
66 }
67
p_statementlist(flag)68 p_statementlist(flag)
69 char flag;
70 {
71 for (; p_statement(flag) >= 0; p_clearerr())
72 ;
73 }
74
p_statement(flag)75 p_statement(flag)
76 char flag;
77 {
78 switch (token) {
79 case T_EOL:
80 (void) s_gettok();
81 return 0;
82 case T_IF:
83 return p_if(flag);
84 default:
85 return p_expression(flag);
86 }
87 }
88
p_if(flag)89 p_if(flag)
90 char flag;
91 {
92 struct value t;
93 char true = 0;
94
95 top:
96 (void) s_gettok();
97
98 if (p_expr(&t, flag) < 0) {
99 p_synerror();
100 return -1;
101 }
102 switch (t.v_type) {
103 case V_NUM:
104 true = !true && t.v_num != 0;
105 break;
106 case V_STR:
107 p_error("if: Numeric value required.");
108 str_free(t.v_str);
109 case V_ERR:
110 flag = 0;
111 break;
112 }
113
114 if (token != T_THEN) {
115 p_synerror();
116 return -1;
117 }
118
119 (void) s_gettok();
120 p_statementlist(flag && true);
121 if (p_erred())
122 return -1;
123
124 if (token == T_ELSIF)
125 goto top;
126
127 if (token == T_ELSE) {
128 (void) s_gettok();
129 p_statementlist(flag && !true);
130 if (p_erred())
131 return -1;
132 }
133
134 if (token == T_ENDIF) {
135 (void) s_gettok();
136 return 0;
137 }
138
139 p_synerror();
140 return -1;
141 }
142
p_expression(flag)143 p_expression(flag)
144 char flag;
145 {
146 struct value t;
147 char *cmd;
148 int p_function(), p_assign();
149
150 switch (token) {
151 case T_NUM:
152 t.v_type = V_NUM;
153 t.v_num = token_num;
154 (void) s_gettok();
155 break;
156 case T_STR:
157 t.v_type = V_STR;
158 t.v_str = token_str;
159 (void) s_gettok();
160 break;
161 default:
162 if (p_expr(&t, flag) < 0)
163 return -1;
164 if (token == T_EOF) {
165 val_free(t);
166 return 0;
167 }
168 }
169 if (token != T_ASSIGN && p_convstr(&t) < 0)
170 return -1;
171 cmd = t.v_type == V_STR ? t.v_str : 0;
172 if ((*(token == T_ASSIGN ? p_assign : p_function))(cmd, &t, flag) < 0) {
173 if (cmd)
174 str_free(cmd);
175 return -1;
176 }
177 if (cmd)
178 str_free(cmd);
179 val_free(t);
180 if (token == T_EOL)
181 (void) s_gettok();
182 else if (token != T_EOF) {
183 p_synerror();
184 return -1;
185 }
186 return 0;
187 }
188
189 p_convstr(v)
190 struct value *v;
191 {
192 if (v->v_type != V_NUM)
193 return 0;
194 if ((v->v_str = str_itoa(v->v_num)) == 0) {
195 p_memerror();
196 v->v_type = V_ERR;
197 return -1;
198 }
199 v->v_type = V_STR;
200 return 0;
201 }
202
p_synerror()203 p_synerror()
204 {
205 if (!cx.x_synerred) {
206 cx.x_synerred = cx.x_erred = 1;
207 error("Syntax error.");
208 }
209 }
210
211 /*VARARGS1*/
p_error(msg,a,b,c)212 p_error(msg, a, b, c)
213 char *msg;
214 {
215 if (!cx.x_erred) {
216 cx.x_erred = 1;
217 error(msg, a, b, c);
218 }
219 }
220
p_memerror()221 p_memerror()
222 {
223 cx.x_erred = cx.x_abort = 1;
224 error("Out of memory.");
225 }
226