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1.1 root 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 [email protected]
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: /*
1.1.1.3 ! root 27: * db_lex.c,v 1.2 1993/05/20 03:39:16 cgd Exp
! 28: *
1.1 root 29: * HISTORY
1.1.1.3 ! root 30: * db_lex.c,v
! 31: * Revision 1.2 1993/05/20 03:39:16 cgd
! 32: * add explicit rcs id
! 33: *
! 34: * Revision 1.1.1.1 1993/03/21 09:46:26 cgd
1.1.1.2 root 35: * initial import of 386bsd-0.1 sources
36: *
1.1 root 37: * Revision 1.1 1992/03/25 21:45:13 pace
38: * Initial revision
39: *
40: * Revision 2.3 91/02/05 17:06:36 mrt
41: * Changed to new Mach copyright
42: * [91/01/31 16:18:20 mrt]
43: *
44: * Revision 2.2 90/08/27 21:51:10 dbg
45: * Add 'dotdot' token.
46: * [90/08/22 dbg]
47: *
48: * Allow backslash to quote any character into an identifier.
49: * Allow colon in identifier for symbol table qualification.
50: * [90/08/16 dbg]
51: * Reduce lint.
52: * [90/08/07 dbg]
53: * Created.
54: * [90/07/25 dbg]
55: *
56: */
57: /*
58: * Author: David B. Golub, Carnegie Mellon University
59: * Date: 7/90
60: */
61: /*
62: * Lexical analyzer.
63: */
64: #include <ddb/db_lex.h>
65:
66: char db_line[120];
67: char * db_lp, *db_endlp;
68:
69: int
70: db_read_line()
71: {
72: int i;
73:
74: i = db_readline(db_line, sizeof(db_line));
75: if (i == 0)
76: return (0); /* EOI */
77: db_lp = db_line;
78: db_endlp = db_lp + i;
79: return (i);
80: }
81:
82: void
83: db_flush_line()
84: {
85: db_lp = db_line;
86: db_endlp = db_line;
87: }
88:
89: int db_look_char = 0;
90:
91: int
92: db_read_char()
93: {
94: int c;
95:
96: if (db_look_char != 0) {
97: c = db_look_char;
98: db_look_char = 0;
99: }
100: else if (db_lp >= db_endlp)
101: c = -1;
102: else
103: c = *db_lp++;
104: return (c);
105: }
106:
107: void
108: db_unread_char(c)
109: {
110: db_look_char = c;
111: }
112:
113: int db_look_token = 0;
114:
115: void
116: db_unread_token(t)
117: int t;
118: {
119: db_look_token = t;
120: }
121:
122: int
123: db_read_token()
124: {
125: int t;
126:
127: if (db_look_token) {
128: t = db_look_token;
129: db_look_token = 0;
130: }
131: else
132: t = db_lex();
133: return (t);
134: }
135:
136: int db_tok_number;
137: char db_tok_string[TOK_STRING_SIZE];
138:
139: int db_radix = 16;
140:
141: void
142: db_flush_lex()
143: {
144: db_flush_line();
145: db_look_char = 0;
146: db_look_token = 0;
147: }
148:
149: int
150: db_lex()
151: {
152: int c;
153:
154: c = db_read_char();
155: while (c <= ' ' || c > '~') {
156: if (c == '\n' || c == -1)
157: return (tEOL);
158: c = db_read_char();
159: }
160:
161: if (c >= '0' && c <= '9') {
162: /* number */
163: int r, digit;
164:
165: if (c > '0')
166: r = db_radix;
167: else {
168: c = db_read_char();
169: if (c == 'O' || c == 'o')
170: r = 8;
171: else if (c == 'T' || c == 't')
172: r = 10;
173: else if (c == 'X' || c == 'x')
174: r = 16;
175: else {
176: r = db_radix;
177: db_unread_char(c);
178: }
179: c = db_read_char();
180: }
181: db_tok_number = 0;
182: for (;;) {
183: if (c >= '0' && c <= ((r == 8) ? '7' : '9'))
184: digit = c - '0';
185: else if (r == 16 && ((c >= 'A' && c <= 'F') ||
186: (c >= 'a' && c <= 'f'))) {
187: if (c >= 'a')
188: digit = c - 'a' + 10;
189: else if (c >= 'A')
190: digit = c - 'A' + 10;
191: }
192: else
193: break;
194: db_tok_number = db_tok_number * r + digit;
195: c = db_read_char();
196: }
197: if ((c >= '0' && c <= '9') ||
198: (c >= 'A' && c <= 'Z') ||
199: (c >= 'a' && c <= 'z') ||
200: (c == '_'))
201: {
202: db_error("Bad character in number\n");
203: db_flush_lex();
204: return (tEOF);
205: }
206: db_unread_char(c);
207: return (tNUMBER);
208: }
209: if ((c >= 'A' && c <= 'Z') ||
210: (c >= 'a' && c <= 'z') ||
211: c == '_' || c == '\\')
212: {
213: /* string */
214: char *cp;
215:
216: cp = db_tok_string;
217: if (c == '\\') {
218: c = db_read_char();
219: if (c == '\n' || c == -1)
220: db_error("Bad escape\n");
221: }
222: *cp++ = c;
223: while (1) {
224: c = db_read_char();
225: if ((c >= 'A' && c <= 'Z') ||
226: (c >= 'a' && c <= 'z') ||
227: (c >= '0' && c <= '9') ||
228: c == '_' || c == '\\' || c == ':')
229: {
230: if (c == '\\') {
231: c = db_read_char();
232: if (c == '\n' || c == -1)
233: db_error("Bad escape\n");
234: }
235: *cp++ = c;
236: if (cp == db_tok_string+sizeof(db_tok_string)) {
237: db_error("String too long\n");
238: db_flush_lex();
239: return (tEOF);
240: }
241: continue;
242: }
243: else {
244: *cp = '\0';
245: break;
246: }
247: }
248: db_unread_char(c);
249: return (tIDENT);
250: }
251:
252: switch (c) {
253: case '+':
254: return (tPLUS);
255: case '-':
256: return (tMINUS);
257: case '.':
258: c = db_read_char();
259: if (c == '.')
260: return (tDOTDOT);
261: db_unread_char(c);
262: return (tDOT);
263: case '*':
264: return (tSTAR);
265: case '/':
266: return (tSLASH);
267: case '=':
268: return (tEQ);
269: case '%':
270: return (tPCT);
271: case '#':
272: return (tHASH);
273: case '(':
274: return (tLPAREN);
275: case ')':
276: return (tRPAREN);
277: case ',':
278: return (tCOMMA);
279: case '"':
280: return (tDITTO);
281: case '$':
282: return (tDOLLAR);
283: case '!':
284: return (tEXCL);
285: case '<':
286: c = db_read_char();
287: if (c == '<')
288: return (tSHIFT_L);
289: db_unread_char(c);
290: break;
291: case '>':
292: c = db_read_char();
293: if (c == '>')
294: return (tSHIFT_R);
295: db_unread_char(c);
296: break;
297: case -1:
298: return (tEOF);
299: }
300: db_printf("Bad character\n");
301: db_flush_lex();
302: return (tEOF);
303: }
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