FreeBSD/Linux Kernel Cross Reference
sys/ddb/db_lex.c
1 /*
2 * Mach Operating System
3 * Copyright (c) 1991,1990 Carnegie Mellon University
4 * All Rights Reserved.
5 *
6 * Permission to use, copy, modify and distribute this software and its
7 * documentation is hereby granted, provided that both the copyright
8 * notice and this permission notice appear in all copies of the
9 * software, derivative works or modified versions, and any portions
10 * thereof, and that both notices appear in supporting documentation.
11 *
12 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
13 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
14 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
15 *
16 * Carnegie Mellon requests users of this software to return to
17 *
18 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
19 * School of Computer Science
20 * Carnegie Mellon University
21 * Pittsburgh PA 15213-3890
22 *
23 * any improvements or extensions that they make and grant Carnegie the
24 * rights to redistribute these changes.
25 *
26 * $FreeBSD: src/sys/ddb/db_lex.c,v 1.18 1999/08/28 00:41:08 peter Exp $
27 * $DragonFly: src/sys/ddb/db_lex.c,v 1.5 2005/12/23 21:35:44 swildner Exp $
28 */
29
30 /*
31 * Author: David B. Golub, Carnegie Mellon University
32 * Date: 7/90
33 */
34 /*
35 * Lexical analyzer.
36 */
37 #include <sys/param.h>
38
39 #include <ddb/ddb.h>
40 #include <ddb/db_lex.h>
41
42 static char db_line[120];
43 static char * db_lp, *db_endlp;
44
45 static int db_lex (void);
46 static void db_flush_line (void);
47 static int db_read_char (void);
48 static void db_unread_char (int);
49
50 int
51 db_read_line(void)
52 {
53 int i;
54
55 i = db_readline(db_line, sizeof(db_line));
56 if (i == 0)
57 return (0); /* EOI */
58 db_lp = db_line;
59 db_endlp = db_lp + i;
60 return (i);
61 }
62
63 static void
64 db_flush_line(void)
65 {
66 db_lp = db_line;
67 db_endlp = db_line;
68 }
69
70 static int db_look_char = 0;
71
72 static int
73 db_read_char(void)
74 {
75 int c;
76
77 if (db_look_char != 0) {
78 c = db_look_char;
79 db_look_char = 0;
80 }
81 else if (db_lp >= db_endlp)
82 c = -1;
83 else
84 c = *db_lp++;
85 return (c);
86 }
87
88 static void
89 db_unread_char(int c)
90 {
91 db_look_char = c;
92 }
93
94 static int db_look_token = 0;
95
96 void
97 db_unread_token(int t)
98 {
99 db_look_token = t;
100 }
101
102 int
103 db_read_token(void)
104 {
105 int t;
106
107 if (db_look_token) {
108 t = db_look_token;
109 db_look_token = 0;
110 }
111 else
112 t = db_lex();
113 return (t);
114 }
115
116 db_expr_t db_tok_number;
117 char db_tok_string[TOK_STRING_SIZE];
118
119 db_expr_t db_radix = 16;
120
121 void
122 db_flush_lex(void)
123 {
124 db_flush_line();
125 db_look_char = 0;
126 db_look_token = 0;
127 }
128
129 static int
130 db_lex(void)
131 {
132 int c;
133
134 c = db_read_char();
135 while (c <= ' ' || c > '~') {
136 if (c == '\n' || c == -1)
137 return (tEOL);
138 c = db_read_char();
139 }
140
141 if (c >= '' && c <= '9') {
142 /* number */
143 int r, digit = 0;
144
145 if (c > '')
146 r = db_radix;
147 else {
148 c = db_read_char();
149 if (c == 'O' || c == 'o')
150 r = 8;
151 else if (c == 'T' || c == 't')
152 r = 10;
153 else if (c == 'X' || c == 'x')
154 r = 16;
155 else {
156 r = db_radix;
157 db_unread_char(c);
158 }
159 c = db_read_char();
160 }
161 db_tok_number = 0;
162 for (;;) {
163 if (c >= '' && c <= ((r == 8) ? '7' : '9'))
164 digit = c - '';
165 else if (r == 16 && ((c >= 'A' && c <= 'F') ||
166 (c >= 'a' && c <= 'f'))) {
167 if (c >= 'a')
168 digit = c - 'a' + 10;
169 else if (c >= 'A')
170 digit = c - 'A' + 10;
171 }
172 else
173 break;
174 db_tok_number = db_tok_number * r + digit;
175 c = db_read_char();
176 }
177 if ((c >= '' && c <= '9') ||
178 (c >= 'A' && c <= 'Z') ||
179 (c >= 'a' && c <= 'z') ||
180 (c == '_'))
181 {
182 db_error("Bad character in number\n");
183 db_flush_lex();
184 return (tEOF);
185 }
186 db_unread_char(c);
187 return (tNUMBER);
188 }
189 if ((c >= 'A' && c <= 'Z') ||
190 (c >= 'a' && c <= 'z') ||
191 c == '_' || c == '\\')
192 {
193 /* string */
194 char *cp;
195
196 cp = db_tok_string;
197 if (c == '\\') {
198 c = db_read_char();
199 if (c == '\n' || c == -1)
200 db_error("Bad escape\n");
201 }
202 *cp++ = c;
203 while (1) {
204 c = db_read_char();
205 if ((c >= 'A' && c <= 'Z') ||
206 (c >= 'a' && c <= 'z') ||
207 (c >= '' && c <= '9') ||
208 c == '_' || c == '\\' || c == ':')
209 {
210 if (c == '\\') {
211 c = db_read_char();
212 if (c == '\n' || c == -1)
213 db_error("Bad escape\n");
214 }
215 *cp++ = c;
216 if (cp == db_tok_string+sizeof(db_tok_string)) {
217 db_error("String too long\n");
218 db_flush_lex();
219 return (tEOF);
220 }
221 continue;
222 }
223 else {
224 *cp = '\0';
225 break;
226 }
227 }
228 db_unread_char(c);
229 return (tIDENT);
230 }
231
232 switch (c) {
233 case '+':
234 return (tPLUS);
235 case '-':
236 return (tMINUS);
237 case '.':
238 c = db_read_char();
239 if (c == '.')
240 return (tDOTDOT);
241 db_unread_char(c);
242 return (tDOT);
243 case '*':
244 return (tSTAR);
245 case '/':
246 return (tSLASH);
247 case '=':
248 return (tEQ);
249 case '%':
250 return (tPCT);
251 case '#':
252 return (tHASH);
253 case '(':
254 return (tLPAREN);
255 case ')':
256 return (tRPAREN);
257 case ',':
258 return (tCOMMA);
259 case '"':
260 return (tDITTO);
261 case '$':
262 return (tDOLLAR);
263 case '!':
264 return (tEXCL);
265 case '<':
266 c = db_read_char();
267 if (c == '<')
268 return (tSHIFT_L);
269 db_unread_char(c);
270 break;
271 case '>':
272 c = db_read_char();
273 if (c == '>')
274 return (tSHIFT_R);
275 db_unread_char(c);
276 break;
277 case -1:
278 return (tEOF);
279 }
280 db_printf("Bad character\n");
281 db_flush_lex();
282 return (tEOF);
283 }
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