1 /* yylex - scanner front-end for flex */
2
3 /*-
4 * Copyright (c) 1990 The Regents of the University of California.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Vern Paxson.
9 *
10 * The United States Government has rights in this work pursuant
11 * to contract no. DE-AC03-76SF00098 between the United States
12 * Department of Energy and the University of California.
13 *
14 * Redistribution and use in source and binary forms are permitted provided
15 * that: (1) source distributions retain this entire copyright notice and
16 * comment, and (2) distributions including binaries display the following
17 * acknowledgement: ``This product includes software developed by the
18 * University of California, Berkeley and its contributors'' in the
19 * documentation or other materials provided with the distribution and in
20 * all advertising materials mentioning features or use of this software.
21 * Neither the name of the University nor the names of its contributors may
22 * be used to endorse or promote products derived from this software without
23 * specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
25 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
26 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
27 */
28
29 /* $Header: /home/daffy/u0/vern/flex/RCS/yylex.c,v 2.10 93/09/16 20:31:48 vern Exp $ */
30
31 #include <ctype.h>
32 #include "flexdef.h"
33 #include "parse.h"
34
35
36 /* yylex - scan for a regular expression token */
37
yylex()38 int yylex()
39 {
40 int toktype;
41 static int beglin = false;
42
43 if ( eofseen )
44 toktype = EOF;
45 else
46 toktype = flexscan();
47
48 if ( toktype == EOF || toktype == 0 )
49 {
50 eofseen = 1;
51
52 if ( sectnum == 1 )
53 {
54 synerr( "premature EOF" );
55 sectnum = 2;
56 toktype = SECTEND;
57 }
58
59 else
60 toktype = 0;
61 }
62
63 if ( trace )
64 {
65 if ( beglin )
66 {
67 fprintf( stderr, "%d\t", num_rules + 1 );
68 beglin = 0;
69 }
70
71 switch ( toktype )
72 {
73 case '<':
74 case '>':
75 case '^':
76 case '$':
77 case '"':
78 case '[':
79 case ']':
80 case '{':
81 case '}':
82 case '|':
83 case '(':
84 case ')':
85 case '-':
86 case '/':
87 case '\\':
88 case '?':
89 case '.':
90 case '*':
91 case '+':
92 case ',':
93 (void) putc( toktype, stderr );
94 break;
95
96 case '\n':
97 (void) putc( '\n', stderr );
98
99 if ( sectnum == 2 )
100 beglin = 1;
101
102 break;
103
104 case SCDECL:
105 fputs( "%s", stderr );
106 break;
107
108 case XSCDECL:
109 fputs( "%x", stderr );
110 break;
111
112 case WHITESPACE:
113 (void) putc( ' ', stderr );
114 break;
115
116 case SECTEND:
117 fputs( "%%\n", stderr );
118
119 /* We set beglin to be true so we'll start
120 * writing out numbers as we echo rules.
121 * flexscan() has already assigned sectnum.
122 */
123
124 if ( sectnum == 2 )
125 beglin = 1;
126
127 break;
128
129 case NAME:
130 fprintf( stderr, "'%s'", nmstr );
131 break;
132
133 case CHAR:
134 switch ( yylval )
135 {
136 case '<':
137 case '>':
138 case '^':
139 case '$':
140 case '"':
141 case '[':
142 case ']':
143 case '{':
144 case '}':
145 case '|':
146 case '(':
147 case ')':
148 case '-':
149 case '/':
150 case '\\':
151 case '?':
152 case '.':
153 case '*':
154 case '+':
155 case ',':
156 fprintf( stderr, "\\%c",
157 yylval );
158 break;
159
160 default:
161 if ( ! isascii( yylval ) ||
162 ! isprint( yylval ) )
163 fprintf( stderr,
164 "\\%.3o",
165 (unsigned int) yylval );
166 else
167 (void) putc( yylval,
168 stderr );
169 break;
170 }
171
172 break;
173
174 case NUMBER:
175 fprintf( stderr, "%d", yylval );
176 break;
177
178 case PREVCCL:
179 fprintf( stderr, "[%d]", yylval );
180 break;
181
182 case EOF_OP:
183 fprintf( stderr, "<<EOF>>" );
184 break;
185
186 case 0:
187 fprintf( stderr, "End Marker" );
188 break;
189
190 default:
191 fprintf( stderr,
192 "*Something Weird* - tok: %d val: %d\n",
193 toktype, yylval );
194 break;
195 }
196 }
197
198 return toktype;
199 }
200