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 * HISTORY
28 * $Log: db_lex.c,v $
29 * Revision 1.1 1992/03/25 21:45:13 pace
30 * Initial revision
31 *
32 * Revision 2.3 91/02/05 17:06:36 mrt
33 * Changed to new Mach copyright
34 * [91/01/31 16:18:20 mrt]
35 *
36 * Revision 2.2 90/08/27 21:51:10 dbg
37 * Add 'dotdot' token.
38 * [90/08/22 dbg]
39 *
40 * Allow backslash to quote any character into an identifier.
41 * Allow colon in identifier for symbol table qualification.
42 * [90/08/16 dbg]
43 * Reduce lint.
44 * [90/08/07 dbg]
45 * Created.
46 * [90/07/25 dbg]
47 *
48 */
49 /*
50 * Author: David B. Golub, Carnegie Mellon University
51 * Date: 7/90
52 */
53 /*
54 * Lexical analyzer.
55 */
56 #include "db_lex.h"
57
58 char db_line[120];
59 char * db_lp, *db_endlp;
60
61 int
db_read_line()62 db_read_line()
63 {
64 int i;
65
66 i = db_readline(db_line, sizeof(db_line));
67 if (i == 0)
68 return (0); /* EOI */
69 db_lp = db_line;
70 db_endlp = db_lp + i;
71 return (i);
72 }
73
74 void
db_flush_line()75 db_flush_line()
76 {
77 db_lp = db_line;
78 db_endlp = db_line;
79 }
80
81 int db_look_char = 0;
82
83 int
db_read_char()84 db_read_char()
85 {
86 int c;
87
88 if (db_look_char != 0) {
89 c = db_look_char;
90 db_look_char = 0;
91 }
92 else if (db_lp >= db_endlp)
93 c = -1;
94 else
95 c = *db_lp++;
96 return (c);
97 }
98
99 void
db_unread_char(c)100 db_unread_char(c)
101 {
102 db_look_char = c;
103 }
104
105 int db_look_token = 0;
106
107 void
db_unread_token(t)108 db_unread_token(t)
109 int t;
110 {
111 db_look_token = t;
112 }
113
114 int
db_read_token()115 db_read_token()
116 {
117 int t;
118
119 if (db_look_token) {
120 t = db_look_token;
121 db_look_token = 0;
122 }
123 else
124 t = db_lex();
125 return (t);
126 }
127
128 int db_tok_number;
129 char db_tok_string[TOK_STRING_SIZE];
130
131 int db_radix = 16;
132
133 void
db_flush_lex()134 db_flush_lex()
135 {
136 db_flush_line();
137 db_look_char = 0;
138 db_look_token = 0;
139 }
140
141 int
db_lex()142 db_lex()
143 {
144 int c;
145
146 c = db_read_char();
147 while (c <= ' ' || c > '~') {
148 if (c == '\n' || c == -1)
149 return (tEOL);
150 c = db_read_char();
151 }
152
153 if (c >= '0' && c <= '9') {
154 /* number */
155 int r, digit;
156
157 if (c > '0')
158 r = db_radix;
159 else {
160 c = db_read_char();
161 if (c == 'O' || c == 'o')
162 r = 8;
163 else if (c == 'T' || c == 't')
164 r = 10;
165 else if (c == 'X' || c == 'x')
166 r = 16;
167 else {
168 r = db_radix;
169 db_unread_char(c);
170 }
171 c = db_read_char();
172 }
173 db_tok_number = 0;
174 for (;;) {
175 if (c >= '0' && c <= ((r == 8) ? '7' : '9'))
176 digit = c - '0';
177 else if (r == 16 && ((c >= 'A' && c <= 'F') ||
178 (c >= 'a' && c <= 'f'))) {
179 if (c >= 'a')
180 digit = c - 'a' + 10;
181 else if (c >= 'A')
182 digit = c - 'A' + 10;
183 }
184 else
185 break;
186 db_tok_number = db_tok_number * r + digit;
187 c = db_read_char();
188 }
189 if ((c >= '0' && c <= '9') ||
190 (c >= 'A' && c <= 'Z') ||
191 (c >= 'a' && c <= 'z') ||
192 (c == '_'))
193 {
194 db_error("Bad character in number\n");
195 db_flush_lex();
196 return (tEOF);
197 }
198 db_unread_char(c);
199 return (tNUMBER);
200 }
201 if ((c >= 'A' && c <= 'Z') ||
202 (c >= 'a' && c <= 'z') ||
203 c == '_' || c == '\\')
204 {
205 /* string */
206 char *cp;
207
208 cp = db_tok_string;
209 if (c == '\\') {
210 c = db_read_char();
211 if (c == '\n' || c == -1)
212 db_error("Bad escape\n");
213 }
214 *cp++ = c;
215 while (1) {
216 c = db_read_char();
217 if ((c >= 'A' && c <= 'Z') ||
218 (c >= 'a' && c <= 'z') ||
219 (c >= '0' && c <= '9') ||
220 c == '_' || c == '\\' || c == ':')
221 {
222 if (c == '\\') {
223 c = db_read_char();
224 if (c == '\n' || c == -1)
225 db_error("Bad escape\n");
226 }
227 *cp++ = c;
228 if (cp == db_tok_string+sizeof(db_tok_string)) {
229 db_error("String too long\n");
230 db_flush_lex();
231 return (tEOF);
232 }
233 continue;
234 }
235 else {
236 *cp = '\0';
237 break;
238 }
239 }
240 db_unread_char(c);
241 return (tIDENT);
242 }
243
244 switch (c) {
245 case '+':
246 return (tPLUS);
247 case '-':
248 return (tMINUS);
249 case '.':
250 c = db_read_char();
251 if (c == '.')
252 return (tDOTDOT);
253 db_unread_char(c);
254 return (tDOT);
255 case '*':
256 return (tSTAR);
257 case '/':
258 return (tSLASH);
259 case '=':
260 return (tEQ);
261 case '%':
262 return (tPCT);
263 case '#':
264 return (tHASH);
265 case '(':
266 return (tLPAREN);
267 case ')':
268 return (tRPAREN);
269 case ',':
270 return (tCOMMA);
271 case '"':
272 return (tDITTO);
273 case '$':
274 return (tDOLLAR);
275 case '!':
276 return (tEXCL);
277 case '<':
278 c = db_read_char();
279 if (c == '<')
280 return (tSHIFT_L);
281 db_unread_char(c);
282 break;
283 case '>':
284 c = db_read_char();
285 if (c == '>')
286 return (tSHIFT_R);
287 db_unread_char(c);
288 break;
289 case -1:
290 return (tEOF);
291 }
292 db_printf("Bad character\n");
293 db_flush_lex();
294 return (tEOF);
295 }
296