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 /*
27 * Author: David B. Golub, Carnegie Mellon University
28 * Date: 7/90
29 */
30 /*
31 * Lexical analyzer.
32 */
33
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD: src/sys/ddb/db_lex.c,v 1.23 2007/12/26 09:33:18 rwatson Exp $");
36
37 #include <sys/param.h>
38 #include <sys/libkern.h>
39
40 #include <ddb/ddb.h>
41 #include <ddb/db_lex.h>
42
43 static char db_line[DB_MAXLINE];
44 static char * db_lp, *db_endlp;
45
46 static int db_lex(void);
47 static void db_flush_line(void);
48 static int db_read_char(void);
49 static void db_unread_char(int);
50
51 int
52 db_read_line()
53 {
54 int i;
55
56 i = db_readline(db_line, sizeof(db_line));
57 if (i == 0)
58 return (0); /* EOI */
59 db_lp = db_line;
60 db_endlp = db_lp + i;
61 return (i);
62 }
63
64 /*
65 * Simulate a line of input into DDB.
66 */
67 void
68 db_inject_line(const char *command)
69 {
70
71 strlcpy(db_line, command, sizeof(db_line));
72 db_lp = db_line;
73 db_endlp = db_lp + strlen(command);
74 }
75
76 /*
77 * In rare cases, we may want to pull the remainder of the line input
78 * verbatim, rather than lexing it. For example, when assigning literal
79 * values associated with scripts. In that case, return a static pointer to
80 * the current location in the input buffer. The caller must be aware that
81 * the contents are not stable if other lex/input calls are made.
82 */
83 char *
84 db_get_line(void)
85 {
86
87 return (db_lp);
88 }
89
90 static void
91 db_flush_line()
92 {
93 db_lp = db_line;
94 db_endlp = db_line;
95 }
96
97 static int db_look_char = 0;
98
99 static int
100 db_read_char()
101 {
102 int c;
103
104 if (db_look_char != 0) {
105 c = db_look_char;
106 db_look_char = 0;
107 }
108 else if (db_lp >= db_endlp)
109 c = -1;
110 else
111 c = *db_lp++;
112 return (c);
113 }
114
115 static void
116 db_unread_char(c)
117 int c;
118 {
119 db_look_char = c;
120 }
121
122 static int db_look_token = 0;
123
124 void
125 db_unread_token(t)
126 int t;
127 {
128 db_look_token = t;
129 }
130
131 int
132 db_read_token()
133 {
134 int t;
135
136 if (db_look_token) {
137 t = db_look_token;
138 db_look_token = 0;
139 }
140 else
141 t = db_lex();
142 return (t);
143 }
144
145 db_expr_t db_tok_number;
146 char db_tok_string[TOK_STRING_SIZE];
147
148 db_expr_t db_radix = 16;
149
150 void
151 db_flush_lex()
152 {
153 db_flush_line();
154 db_look_char = 0;
155 db_look_token = 0;
156 }
157
158 static int
159 db_lex()
160 {
161 int c;
162
163 c = db_read_char();
164 while (c <= ' ' || c > '~') {
165 if (c == '\n' || c == -1)
166 return (tEOL);
167 c = db_read_char();
168 }
169
170 if (c >= '' && c <= '9') {
171 /* number */
172 int r, digit = 0;
173
174 if (c > '')
175 r = db_radix;
176 else {
177 c = db_read_char();
178 if (c == 'O' || c == 'o')
179 r = 8;
180 else if (c == 'T' || c == 't')
181 r = 10;
182 else if (c == 'X' || c == 'x')
183 r = 16;
184 else {
185 r = db_radix;
186 db_unread_char(c);
187 }
188 c = db_read_char();
189 }
190 db_tok_number = 0;
191 for (;;) {
192 if (c >= '' && c <= ((r == 8) ? '7' : '9'))
193 digit = c - '';
194 else if (r == 16 && ((c >= 'A' && c <= 'F') ||
195 (c >= 'a' && c <= 'f'))) {
196 if (c >= 'a')
197 digit = c - 'a' + 10;
198 else if (c >= 'A')
199 digit = c - 'A' + 10;
200 }
201 else
202 break;
203 db_tok_number = db_tok_number * r + digit;
204 c = db_read_char();
205 }
206 if ((c >= '' && c <= '9') ||
207 (c >= 'A' && c <= 'Z') ||
208 (c >= 'a' && c <= 'z') ||
209 (c == '_'))
210 {
211 db_error("Bad character in number\n");
212 db_flush_lex();
213 return (tEOF);
214 }
215 db_unread_char(c);
216 return (tNUMBER);
217 }
218 if ((c >= 'A' && c <= 'Z') ||
219 (c >= 'a' && c <= 'z') ||
220 c == '_' || c == '\\')
221 {
222 /* string */
223 char *cp;
224
225 cp = db_tok_string;
226 if (c == '\\') {
227 c = db_read_char();
228 if (c == '\n' || c == -1)
229 db_error("Bad escape\n");
230 }
231 *cp++ = c;
232 while (1) {
233 c = db_read_char();
234 if ((c >= 'A' && c <= 'Z') ||
235 (c >= 'a' && c <= 'z') ||
236 (c >= '' && c <= '9') ||
237 c == '_' || c == '\\' || c == ':' || c == '.')
238 {
239 if (c == '\\') {
240 c = db_read_char();
241 if (c == '\n' || c == -1)
242 db_error("Bad escape\n");
243 }
244 *cp++ = c;
245 if (cp == db_tok_string+sizeof(db_tok_string)) {
246 db_error("String too long\n");
247 db_flush_lex();
248 return (tEOF);
249 }
250 continue;
251 }
252 else {
253 *cp = '\0';
254 break;
255 }
256 }
257 db_unread_char(c);
258 return (tIDENT);
259 }
260
261 switch (c) {
262 case '+':
263 return (tPLUS);
264 case '-':
265 return (tMINUS);
266 case '.':
267 c = db_read_char();
268 if (c == '.')
269 return (tDOTDOT);
270 db_unread_char(c);
271 return (tDOT);
272 case '*':
273 return (tSTAR);
274 case '/':
275 return (tSLASH);
276 case '=':
277 return (tEQ);
278 case '%':
279 return (tPCT);
280 case '#':
281 return (tHASH);
282 case '(':
283 return (tLPAREN);
284 case ')':
285 return (tRPAREN);
286 case ',':
287 return (tCOMMA);
288 case '"':
289 return (tDITTO);
290 case '$':
291 return (tDOLLAR);
292 case '!':
293 return (tEXCL);
294 case ';':
295 return (tSEMI);
296 case '<':
297 c = db_read_char();
298 if (c == '<')
299 return (tSHIFT_L);
300 db_unread_char(c);
301 break;
302 case '>':
303 c = db_read_char();
304 if (c == '>')
305 return (tSHIFT_R);
306 db_unread_char(c);
307 break;
308 case -1:
309 return (tEOF);
310 }
311 db_printf("Bad character\n");
312 db_flush_lex();
313 return (tEOF);
314 }
315
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