File: rexp3.c

package info (click to toggle)
mawk 1.3.3-17
  • links: PTS, VCS
  • area: main
  • in suites: buster, jessie, jessie-kfreebsd, stretch, wheezy
  • size: 1,484 kB
  • ctags: 1,506
  • sloc: ansic: 13,008; yacc: 994; awk: 629; makefile: 113; sh: 107
file content (339 lines) | stat: -rw-r--r-- 7,457 bytes parent folder | download | duplicates (6)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339

/********************************************
rexp3.c
copyright 1991, Michael D. Brennan

This is a source file for mawk, an implementation of
the AWK programming language.

Mawk is distributed without warranty under the terms of
the GNU General Public License, version 2, 1991.
********************************************/

/*$Log: rexp3.c,v $
 * Revision 1.3  1993/07/24  17:55:15  mike
 * more cleanup
 *
 * Revision 1.2	 1993/07/23  13:21:48  mike
 * cleanup rexp code
 *
 * Revision 1.1.1.1  1993/07/03	 18:58:28  mike
 * move source to cvs
 *
 * Revision 3.6	 1992/12/24  00:44:53  mike
 * fixed potential LMDOS bozo with M_STR+U_ON+END_ON
 * fixed minor bug in M_CLASS+U_ON+END_ON
 *
 * Revision 3.5	 1992/01/21  17:33:20  brennan
 * added some casts so that character classes work with signed chars
 *
 * Revision 3.4	 91/10/29  10:54:09  brennan
 * SIZE_T
 *
 * Revision 3.3	 91/08/13  09:10:18  brennan
 * VERSION .9994
 *
 * Revision 3.2	 91/06/10  16:18:17  brennan
 * changes for V7
 *
 * Revision 3.1	 91/06/07  10:33:28  brennan
 * VERSION 0.995
 *
 * Revision 1.4	 91/05/31  10:56:32  brennan
 * stack_empty hack for DOS large model
 *
*/

/*  match a string against a machine   */

#include "rexp.h"



extern RT_STATE *RE_run_stack_base ;
extern RT_STATE *RE_run_stack_limit ;
extern RT_STATE *RE_run_stack_empty ;

RT_STATE *RE_new_run_stack() ;


#define	 push(mx,sx,ssx,ux)   if (++stackp == RE_run_stack_limit)\
				stackp = RE_new_run_stack() ;\
stackp->m=(mx);stackp->s=(sx);stackp->ss=(ssx);\
stackp->u = (ux)


#define	  CASE_UANY(x)	case  x + U_OFF :  case	 x + U_ON

/* returns start of first longest match and the length by
   reference.  If no match returns NULL and length zero */

   char *REmatch(str, machine, lenp)
   char *str ;
   PTR machine ;
   unsigned *lenp ;
{
   register STATE *m = (STATE *) machine ;
   register char *s = str ;
   char *ss ;
   register RT_STATE *stackp ;
   int u_flag, t ;
   char *str_end, *ts ;

   /* state of current best match stored here */
   char *cb_ss ;		 /* the start */
   char *cb_e ;			 /* the end , pts at first char not matched */

   *lenp = 0 ;

   /* check for the easy case */
   if ((m + 1)->type == M_ACCEPT && m->type == M_STR)
   {
      if (ts = str_str(s, m->data.str, m->len))	 *lenp = m->len ;
      return ts ;
   }

   u_flag = U_ON ; cb_ss = ss = str_end = (char *) 0 ;
   stackp = RE_run_stack_empty ;
   goto reswitch ;

refill :
   if (stackp == RE_run_stack_empty)
   {
      if (cb_ss)  *lenp = cb_e - cb_ss ;
      return cb_ss ;
   }
   ss = stackp->ss ;
   s = stackp--->s ;
   if (cb_ss)			/* does new state start too late ? */
   {
      if (ss)
      {
	 if (cb_ss < ss)  goto refill ;
      }
      else if (cb_ss < s)  goto refill ;
   }

   m = (stackp + 1)->m ;
   u_flag = (stackp + 1)->u ;


reswitch  :

   switch (m->type + u_flag)
   {
      case M_STR + U_OFF + END_OFF:
	 if (strncmp(s, m->data.str, m->len))  goto refill ;
	 if (!ss)
	 {
	    if (cb_ss && s > cb_ss)  goto refill ;
	    else  ss = s ;
	 }
	 s += m->len ;	m++ ;
	 goto reswitch ;

      case M_STR + U_OFF + END_ON:
	 if (strcmp(s, m->data.str))  goto refill ;
	 if (!ss)
	 {
	    if (cb_ss && s > cb_ss)  goto refill ;
	    else  ss = s ;
	 }
	 s += m->len ;	m++ ;
	 goto reswitch ;

      case M_STR + U_ON + END_OFF:
	 if (!(s = str_str(s, m->data.str, m->len)))  goto refill ;
	 push(m, s + 1, ss, U_ON) ;
	 if (!ss)
	 {
	    if (cb_ss && s > cb_ss)  goto refill ;
	    else  ss = s ;
	 }
	 s += m->len ; m++ ; u_flag = U_OFF ;
	 goto reswitch ;

      case M_STR + U_ON + END_ON:
	 if (!str_end)	str_end = s + strlen(s) ;
	 t = (str_end - s) - m->len ;
	 if (t < 0 || memcmp(ts = s + t, m->data.str, m->len))
	    goto refill ;
	 if (!ss)
	 {
	    if (cb_ss && ts > cb_ss)  goto refill ;
	    else  ss = ts ;
	 }
	 s = str_end ; m++ ; u_flag = U_OFF ;
	 goto reswitch ;

      case M_CLASS + U_OFF + END_OFF:
	 if (!ison(*m->data.bvp, s[0]))	 goto refill ;
	 if (!ss)
	 {
	    if (cb_ss && s > cb_ss)  goto refill ;
	    else  ss = s ;
	 }
	 s++ ; m++ ;
	 goto reswitch ;

      case M_CLASS + U_OFF + END_ON:
	 if (s[1] || !ison(*m->data.bvp, s[0]))	 goto refill ;
	 if (!ss)
	 {
	    if (cb_ss && s > cb_ss)  goto refill ;
	    else  ss = s ;
	 }
	 s++ ; m++ ;
	 goto reswitch ;

      case M_CLASS + U_ON + END_OFF:
	 while (!ison(*m->data.bvp, s[0]))
	 {
	    if (s[0] == 0)  goto refill ;
	    else  s++ ;
	 }
	 s++ ;
	 push(m, s, ss, U_ON) ;
	 if (!ss)
	 {
	    if (cb_ss && s - 1 > cb_ss)	 goto refill ;
	    else  ss = s - 1 ;
	 }
	 m++ ; u_flag = U_OFF ;
	 goto reswitch ;

      case M_CLASS + U_ON + END_ON:
	 if (!str_end)	str_end = s + strlen(s) ;
	 if (s[0] == 0 || !ison(*m->data.bvp, str_end[-1]))
	    goto refill ;
	 if (!ss)
	 {
	    if (cb_ss && str_end - 1 > cb_ss)  goto refill ;
	    else  ss = str_end - 1 ;
	 }
	 s = str_end ; m++ ; u_flag = U_OFF ;
	 goto reswitch ;

      case M_ANY + U_OFF + END_OFF:
	 if (s[0] == 0)	 goto refill ;
	 if (!ss)
	 {
	    if (cb_ss && s > cb_ss)  goto refill ;
	    else  ss = s ;
	 }
	 s++ ; m++ ;
	 goto reswitch ;

      case M_ANY + U_OFF + END_ON:
	 if (s[0] == 0 || s[1] != 0)  goto refill ;
	 if (!ss)
	 {
	    if (cb_ss && s > cb_ss)  goto refill ;
	    else  ss = s ;
	 }
	 s++ ; m++ ;
	 goto reswitch ;

      case M_ANY + U_ON + END_OFF:
	 if (s[0] == 0)	 goto refill ;
	 s++ ;
	 push(m, s, ss, U_ON) ;
	 if (!ss)
	 {
	    if (cb_ss && s - 1 > cb_ss)	 goto refill ;
	    else  ss = s - 1 ;
	 }
	 m++ ; u_flag = U_OFF ;
	 goto reswitch ;

      case M_ANY + U_ON + END_ON:
	 if (s[0] == 0)	 goto refill ;
	 if (!str_end)	str_end = s + strlen(s) ;
	 if (!ss)
	 {
	    if (cb_ss && str_end - 1 > cb_ss)  goto refill ;
	    else  ss = str_end - 1 ;
	 }
	 s = str_end ; m++ ; u_flag = U_OFF ;
	 goto reswitch ;

      case M_START + U_OFF + END_OFF:
      case M_START + U_ON + END_OFF:
	 if (s != str)	goto refill ;
	 ss = s ;
	 m++ ;	u_flag = U_OFF ;
	 goto reswitch ;

      case M_START + U_OFF + END_ON:
      case M_START + U_ON + END_ON:
	 if (s != str || s[0] != 0)  goto refill ;
	 ss = s ;
	 m++ ; u_flag = U_OFF ;
	 goto reswitch ;

      case M_END + U_OFF:
	 if (s[0] != 0)	 goto refill ;
	 if (!ss)
	 {
	    if (cb_ss && s > cb_ss)  goto refill ;
	    else  ss = s ;
	 }
	 m++ ; goto reswitch ;

      case M_END + U_ON:
	 s = str_end ? str_end : (str_end = s + strlen(s)) ;
	 if (!ss)
	 {
	    if (cb_ss && s > cb_ss)  goto refill ;
	    else  ss = s ;
	 }
	 m++ ; u_flag = U_OFF ;
	 goto reswitch ;

       CASE_UANY(M_U):
	 if (!ss)
	 {
	    if (cb_ss && s > cb_ss)  goto refill ;
	    else  ss = s ;
	 }
	 u_flag = U_ON ; m++ ;
	 goto reswitch ;

       CASE_UANY(M_1J):
	 m += m->data.jump ;
	 goto reswitch ;

       CASE_UANY(M_2JA):	/* take the non jump branch */
	 push(m + m->data.jump, s, ss, u_flag) ;
	 m++ ;
	 goto reswitch ;

       CASE_UANY(M_2JB):	/* take the jump branch */
	 push(m + 1, s, ss, u_flag) ;
	 m += m->data.jump ;
	 goto reswitch ;

      case M_ACCEPT + U_OFF:
	 if (!ss)  ss = s ;
	 if (!cb_ss || ss < cb_ss || ss == cb_ss && s > cb_e)
	 {
	    /* we have a new current best */
	    cb_ss = ss ; cb_e = s ;
	 }
	 goto refill ;

      case M_ACCEPT + U_ON:
	 if (!ss)  ss = s ;
	 else  s = str_end ? str_end : (str_end = s + strlen(s)) ;

	 if (!cb_ss || ss < cb_ss || ss == cb_ss && s > cb_e)
	 {
	    /* we have a new current best */
	    cb_ss = ss ; cb_e = s ;
	 }
	 goto refill ;

      default:
	 RE_panic("unexpected case in REmatch") ;
   }
}