1 | /* $NetBSD: db_lex.c,v 1.22 2011/05/26 15:34:14 joerg 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 1.22 2011/05/26 15:34:14 joerg Exp $" ); |
38 | |
39 | #include <sys/param.h> |
40 | #include <sys/systm.h> |
41 | |
42 | #include <ddb/ddb.h> |
43 | |
44 | db_expr_t db_tok_number; |
45 | char db_tok_string[TOK_STRING_SIZE]; |
46 | |
47 | static char db_line[DB_LINE_MAXLEN]; |
48 | static const char *db_lp; |
49 | static const char *db_endlp; |
50 | |
51 | static int db_look_char = 0; |
52 | static int db_look_token = 0; |
53 | |
54 | static void db_flush_line(void); |
55 | static int db_read_char(void); |
56 | static void db_unread_char(int); |
57 | static int db_lex(void); |
58 | |
59 | int |
60 | db_read_line(void) |
61 | { |
62 | int i; |
63 | |
64 | i = db_readline(db_line, sizeof(db_line)); |
65 | if (i == 0) |
66 | return (0); /* EOI */ |
67 | db_set_line(db_line, db_line + i); |
68 | return (i); |
69 | } |
70 | |
71 | void |
72 | db_set_line(const char *sp, const char *ep) |
73 | { |
74 | |
75 | db_lp = sp; |
76 | db_endlp = ep; |
77 | } |
78 | |
79 | static void |
80 | db_flush_line(void) |
81 | { |
82 | |
83 | db_lp = db_line; |
84 | db_endlp = db_line; |
85 | } |
86 | |
87 | static int |
88 | db_read_char(void) |
89 | { |
90 | int c; |
91 | |
92 | if (db_look_char != 0) { |
93 | c = db_look_char; |
94 | db_look_char = 0; |
95 | } |
96 | else if (db_lp >= db_endlp) |
97 | c = -1; |
98 | else |
99 | c = *db_lp++; |
100 | return (c); |
101 | } |
102 | |
103 | static void |
104 | db_unread_char(int c) |
105 | { |
106 | |
107 | db_look_char = c; |
108 | } |
109 | |
110 | void |
111 | db_unread_token(int t) |
112 | { |
113 | |
114 | db_look_token = t; |
115 | } |
116 | |
117 | int |
118 | db_read_token(void) |
119 | { |
120 | int t; |
121 | |
122 | if (db_look_token) { |
123 | t = db_look_token; |
124 | db_look_token = 0; |
125 | } |
126 | else |
127 | t = db_lex(); |
128 | return (t); |
129 | } |
130 | |
131 | int db_radix = 16; |
132 | |
133 | /* |
134 | * Convert the number to a string in the current radix. |
135 | * This replaces the non-standard %n printf() format. |
136 | */ |
137 | |
138 | char * |
139 | db_num_to_str(db_expr_t val) |
140 | { |
141 | |
142 | /* |
143 | * 2 chars for "0x", 1 for a sign ("-") |
144 | * up to 21 chars for a 64-bit number: |
145 | * % echo 2^64 | bc | wc -c |
146 | * 21 |
147 | * and 1 char for a terminal NUL |
148 | * 2+1+21+1 => 25 |
149 | */ |
150 | static char buf[25]; |
151 | |
152 | if (db_radix == 16) |
153 | snprintf(buf, sizeof(buf), "%" DDB_EXPR_FMT "x" , val); |
154 | else if (db_radix == 8) |
155 | snprintf(buf, sizeof(buf), "%" DDB_EXPR_FMT "o" , val); |
156 | else |
157 | snprintf(buf, sizeof(buf), "%" DDB_EXPR_FMT "u" , val); |
158 | |
159 | return (buf); |
160 | } |
161 | |
162 | void |
163 | db_flush_lex(void) |
164 | { |
165 | |
166 | db_flush_line(); |
167 | db_look_char = 0; |
168 | db_look_token = 0; |
169 | } |
170 | |
171 | static int |
172 | db_lex(void) |
173 | { |
174 | int c; |
175 | |
176 | c = db_read_char(); |
177 | while (c <= ' ' || c > '~') { |
178 | if (c == '\n' || c == -1) |
179 | return (tEOL); |
180 | c = db_read_char(); |
181 | } |
182 | |
183 | if (c >= '0' && c <= '9') { |
184 | /* number */ |
185 | db_expr_t r, digit = 0; |
186 | |
187 | if (c > '0') |
188 | r = db_radix; |
189 | else { |
190 | c = db_read_char(); |
191 | if (c == 'O' || c == 'o') |
192 | r = 8; |
193 | else if (c == 'T' || c == 't') |
194 | r = 10; |
195 | else if (c == 'X' || c == 'x') |
196 | r = 16; |
197 | else { |
198 | r = db_radix; |
199 | db_unread_char(c); |
200 | } |
201 | c = db_read_char(); |
202 | } |
203 | db_tok_number = 0; |
204 | for (;;) { |
205 | if (c >= '0' && c <= ((r == 8) ? '7' : '9')) |
206 | digit = c - '0'; |
207 | else if (r == 16 && ((c >= 'A' && c <= 'F') || |
208 | (c >= 'a' && c <= 'f'))) { |
209 | if (c >= 'a') |
210 | digit = c - 'a' + 10; |
211 | else if (c >= 'A') |
212 | digit = c - 'A' + 10; |
213 | } |
214 | else |
215 | break; |
216 | db_tok_number = db_tok_number * r + digit; |
217 | c = db_read_char(); |
218 | } |
219 | if ((c >= '0' && c <= '9') || |
220 | (c >= 'A' && c <= 'Z') || |
221 | (c >= 'a' && c <= 'z') || |
222 | (c == '_')) { |
223 | db_error("Bad character in number\n" ); |
224 | /*NOTREACHED*/ |
225 | } |
226 | db_unread_char(c); |
227 | return (tNUMBER); |
228 | } |
229 | if ((c >= 'A' && c <= 'Z') || |
230 | (c >= 'a' && c <= 'z') || |
231 | c == '_' || c == '\\') { |
232 | /* string */ |
233 | char *cp; |
234 | |
235 | cp = db_tok_string; |
236 | if (c == '\\') { |
237 | c = db_read_char(); |
238 | if (c == '\n' || c == -1) { |
239 | db_error("Bad escape\n" ); |
240 | /*NOTREACHED*/ |
241 | } |
242 | } |
243 | *cp++ = c; |
244 | while (1) { |
245 | c = db_read_char(); |
246 | if ((c >= 'A' && c <= 'Z') || |
247 | (c >= 'a' && c <= 'z') || |
248 | (c >= '0' && c <= '9') || |
249 | c == '_' || c == '\\' || c == ':') { |
250 | if (c == '\\') { |
251 | c = db_read_char(); |
252 | if (c == '\n' || c == -1) { |
253 | db_error("Bad escape\n" ); |
254 | /*NOTREACHED*/ |
255 | } |
256 | } |
257 | *cp++ = c; |
258 | if (cp == db_tok_string+sizeof(db_tok_string)) { |
259 | db_error("String too long\n" ); |
260 | /*NOTREACHED*/ |
261 | } |
262 | continue; |
263 | } else { |
264 | *cp = '\0'; |
265 | break; |
266 | } |
267 | } |
268 | db_unread_char(c); |
269 | return (tIDENT); |
270 | } |
271 | |
272 | switch (c) { |
273 | case '+': |
274 | return (tPLUS); |
275 | case '-': |
276 | return (tMINUS); |
277 | case '.': |
278 | c = db_read_char(); |
279 | if (c == '.') |
280 | return (tDOTDOT); |
281 | db_unread_char(c); |
282 | return (tDOT); |
283 | case '*': |
284 | return (tSTAR); |
285 | case '/': |
286 | return (tSLASH); |
287 | case '=': |
288 | return (tEQ); |
289 | case '%': |
290 | return (tPCT); |
291 | case '#': |
292 | return (tHASH); |
293 | case '(': |
294 | return (tLPAREN); |
295 | case ')': |
296 | return (tRPAREN); |
297 | case ',': |
298 | return (tCOMMA); |
299 | case '"': |
300 | return (tDITTO); |
301 | case '$': |
302 | return (tDOLLAR); |
303 | case '!': |
304 | return (tEXCL); |
305 | case '<': |
306 | c = db_read_char(); |
307 | if (c == '<') |
308 | return (tSHIFT_L); |
309 | db_unread_char(c); |
310 | break; |
311 | case '>': |
312 | c = db_read_char(); |
313 | if (c == '>') |
314 | return (tSHIFT_R); |
315 | db_unread_char(c); |
316 | break; |
317 | case -1: |
318 | return (tEOF); |
319 | } |
320 | db_printf("Bad character\n" ); |
321 | db_flush_lex(); |
322 | return (tEOF); |
323 | } |
324 | |
325 | /* |
326 | * Utility routine - discard tokens through end-of-line. |
327 | */ |
328 | void |
329 | db_skip_to_eol(void) |
330 | { |
331 | int t; |
332 | |
333 | do { |
334 | t = db_read_token(); |
335 | } while (t != tEOL); |
336 | } |
337 | |
338 | void |
339 | db_error(const char *s) |
340 | { |
341 | |
342 | if (s) |
343 | db_printf("%s" , s); |
344 | db_flush_lex(); |
345 | longjmp(db_recover); |
346 | } |
347 | |