1 /* $NetBSD: db_lex.c,v 1.27 2022/08/30 22:37:03 riastradh Exp $ */
2
3 /*
4 * Mach Operating System
5 * Copyright (c) 1991,1990 Carnegie Mellon University
6 * All Rights Reserved.
7 *
8 * Permission to use, copy, modify and distribute this software and its
9 * documentation is hereby granted, provided that both the copyright
10 * notice and this permission notice appear in all copies of the
11 * software, derivative works or modified versions, and any portions
12 * thereof, and that both notices appear in supporting documentation.
13 *
14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
15 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
16 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
17 *
18 * Carnegie Mellon requests users of this software to return to
19 *
20 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
21 * School of Computer Science
22 * Carnegie Mellon University
23 * Pittsburgh PA 15213-3890
24 *
25 * any improvements or extensions that they make and grant Carnegie the
26 * rights to redistribute these changes.
27 *
28 * Author: David B. Golub, Carnegie Mellon University
29 * Date: 7/90
30 */
31
32 /*
33 * Lexical analyzer.
34 */
35
36 #include <sys/cdefs.h>
37 __KERNEL_RCSID(0, "$NetBSD: db_lex.c,v 1.27 2022/08/30 22:37:03 riastradh Exp $");
38
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/cpu.h>
42
43 #include <ddb/ddb.h>
44
45 db_expr_t db_tok_number;
46 char db_tok_string[TOK_STRING_SIZE];
47
48 static char db_line[DB_LINE_MAXLEN];
49 static const char *db_lp;
50 static const char *db_endlp;
51
52 static int db_look_char = 0;
53 static int db_look_token = 0;
54
55 static void db_flush_line(void);
56 static int db_read_char(void);
57 static void db_unread_char(int);
58 static int db_lex(void);
59
60 int
db_read_line(void)61 db_read_line(void)
62 {
63 int i;
64
65 #ifdef _KERNEL
66 /*
67 * crash(8) prints the prompt using libedit. That's why we used to
68 * print it in db_readline(). But now people are using db_read_line()
69 * for general purpose input, so..
70 */
71 #ifdef MULTIPROCESSOR
72 db_printf("db{%ld}> ", (long)cpu_number());
73 #else
74 db_printf("db> ");
75 #endif
76 #endif
77 i = db_readline(db_line, sizeof(db_line));
78 if (i == 0)
79 return (0); /* EOI */
80 db_set_line(db_line, db_line + i);
81 return (i);
82 }
83
84 void
db_set_line(const char * sp,const char * ep)85 db_set_line(const char *sp, const char *ep)
86 {
87
88 db_lp = sp;
89 db_endlp = ep;
90 }
91
92 void
db_get_line(const char ** psp,const char ** pep)93 db_get_line(const char **psp, const char **pep)
94 {
95
96 if (psp != NULL)
97 *psp = db_lp;
98 if (pep != NULL)
99 *pep = db_endlp;
100 }
101
102 static void
db_flush_line(void)103 db_flush_line(void)
104 {
105
106 db_lp = db_line;
107 db_endlp = db_line;
108 }
109
110 static int
db_read_char(void)111 db_read_char(void)
112 {
113 int c;
114
115 if (db_look_char != 0) {
116 c = db_look_char;
117 db_look_char = 0;
118 }
119 else if (db_lp >= db_endlp)
120 c = -1;
121 else
122 c = *db_lp++;
123 return (c);
124 }
125
126 static void
db_unread_char(int c)127 db_unread_char(int c)
128 {
129
130 db_look_char = c;
131 }
132
133 void
db_unread_token(int t)134 db_unread_token(int t)
135 {
136
137 db_look_token = t;
138 }
139
140 int
db_read_token(void)141 db_read_token(void)
142 {
143 int t;
144
145 if (db_look_token) {
146 t = db_look_token;
147 db_look_token = 0;
148 }
149 else
150 t = db_lex();
151 return (t);
152 }
153
154 int db_radix = 16;
155
156 /*
157 * Convert the number to a string in the current radix.
158 * This replaces the non-standard %n printf() format.
159 */
160
161 char *
db_num_to_str(db_expr_t val)162 db_num_to_str(db_expr_t val)
163 {
164
165 /*
166 * 2 chars for "0x", 1 for a sign ("-")
167 * up to 21 chars for a 64-bit number:
168 * % echo 2^64 | bc | wc -c
169 * 21
170 * and 1 char for a terminal NUL
171 * 2+1+21+1 => 25
172 */
173 static char buf[25];
174
175 db_num_to_strbuf(val, buf, sizeof(buf));
176
177 return (buf);
178 }
179
180 void
db_num_to_strbuf(db_expr_t val,char * buf,size_t len)181 db_num_to_strbuf(db_expr_t val, char *buf, size_t len)
182 {
183
184 if (db_radix == 16)
185 snprintf(buf, len, "%" DDB_EXPR_FMT "x", val);
186 else if (db_radix == 8)
187 snprintf(buf, len, "%" DDB_EXPR_FMT "o", val);
188 else
189 snprintf(buf, len, "%" DDB_EXPR_FMT "u", val);
190 }
191
192 void
db_flush_lex(void)193 db_flush_lex(void)
194 {
195
196 db_flush_line();
197 db_look_char = 0;
198 db_look_token = 0;
199 }
200
201 static int
db_lex(void)202 db_lex(void)
203 {
204 int c;
205
206 c = db_read_char();
207 while (c <= ' ' || c > '~') {
208 if (c == '\n' || c == -1)
209 return (tEOL);
210 c = db_read_char();
211 }
212
213 if (c >= '0' && c <= '9') {
214 /* number */
215 db_expr_t r, digit = 0;
216
217 if (c > '0')
218 r = db_radix;
219 else {
220 c = db_read_char();
221 if (c == 'O' || c == 'o')
222 r = 8;
223 else if (c == 'T' || c == 't')
224 r = 10;
225 else if (c == 'X' || c == 'x')
226 r = 16;
227 else {
228 r = db_radix;
229 db_unread_char(c);
230 }
231 c = db_read_char();
232 }
233 db_tok_number = 0;
234 for (;;) {
235 if (c >= '0' && c <= ((r == 8) ? '7' : '9'))
236 digit = c - '0';
237 else if (r == 16) {
238 if (c >= 'A' && c <= 'F')
239 digit = c - 'A' + 10;
240 else if (c >= 'a' && c <= 'f')
241 digit = c - 'a' + 10;
242 else
243 break;
244 } else
245 break;
246 db_tok_number = db_tok_number * r + digit;
247 c = db_read_char();
248 }
249 if ((c >= '0' && c <= '9') ||
250 (c >= 'A' && c <= 'Z') ||
251 (c >= 'a' && c <= 'z') ||
252 (c == '_')) {
253 db_error("Bad character in number\n");
254 /*NOTREACHED*/
255 }
256 db_unread_char(c);
257 return (tNUMBER);
258 }
259 if ((c >= 'A' && c <= 'Z') ||
260 (c >= 'a' && c <= 'z') ||
261 c == '_' || c == '\\') {
262 /* string */
263 char *cp;
264
265 cp = db_tok_string;
266 if (c == '\\') {
267 c = db_read_char();
268 if (c == '\n' || c == -1) {
269 db_error("Bad escape\n");
270 /*NOTREACHED*/
271 }
272 }
273 *cp++ = c;
274 while (1) {
275 c = db_read_char();
276 if ((c >= 'A' && c <= 'Z') ||
277 (c >= 'a' && c <= 'z') ||
278 (c >= '0' && c <= '9') ||
279 c == '_' || c == '\\' || c == ':') {
280 if (c == '\\') {
281 c = db_read_char();
282 if (c == '\n' || c == -1) {
283 db_error("Bad escape\n");
284 /*NOTREACHED*/
285 }
286 }
287 *cp++ = c;
288 if (cp == db_tok_string+sizeof(db_tok_string)) {
289 db_error("String too long\n");
290 /*NOTREACHED*/
291 }
292 continue;
293 } else {
294 *cp = '\0';
295 break;
296 }
297 }
298 db_unread_char(c);
299 return (tIDENT);
300 }
301
302 switch (c) {
303 case '+':
304 return (tPLUS);
305 case '-':
306 return (tMINUS);
307 case '.':
308 c = db_read_char();
309 if (c == '.')
310 return (tDOTDOT);
311 db_unread_char(c);
312 return (tDOT);
313 case '*':
314 return (tSTAR);
315 case '/':
316 return (tSLASH);
317 case '=':
318 return (tEQ);
319 case '%':
320 return (tPCT);
321 case '#':
322 return (tHASH);
323 case '(':
324 return (tLPAREN);
325 case ')':
326 return (tRPAREN);
327 case ',':
328 return (tCOMMA);
329 case '"':
330 return (tDITTO);
331 case '$':
332 return (tDOLLAR);
333 case '!':
334 return (tEXCL);
335 case '<':
336 c = db_read_char();
337 if (c == '<')
338 return (tSHIFT_L);
339 db_unread_char(c);
340 break;
341 case '>':
342 c = db_read_char();
343 if (c == '>')
344 return (tSHIFT_R);
345 db_unread_char(c);
346 break;
347 case -1:
348 return (tEOF);
349 }
350 db_printf("Bad character\n");
351 db_flush_lex();
352 return (tEOF);
353 }
354
355 /*
356 * Utility routine - discard tokens through end-of-line.
357 */
358 void
db_skip_to_eol(void)359 db_skip_to_eol(void)
360 {
361 int t;
362
363 do {
364 t = db_read_token();
365 } while (t != tEOL);
366 }
367
368 void
db_error(const char * s)369 db_error(const char *s)
370 {
371
372 if (s)
373 db_printf("%s", s);
374 db_flush_lex();
375 longjmp(db_recover);
376 }
377