1 %{
2 
3 #include <LYLeaks.h>
4 
5 /*
6  *  $LynxId: parsdate.y,v 1.20 2013/01/05 01:58:50 tom Exp $
7  *
8  *  This module is adapted and extended from tin, to use for LYmktime().
9  *
10  *  Project   : tin - a Usenet reader
11  *  Module    : parsedate.y
12  *  Author    : S. Bellovin, R. $alz, J. Berets, P. Eggert
13  *  Created   : 1990-08-01
14  *  Updated   : 2008-06-30 (by Thomas Dickey, for Lynx)
15  *  Notes     : This grammar has 8 shift/reduce conflicts.
16  *
17  *              Originally written by Steven M. Bellovin <smb@research.att.com>
18  *              while at the University of North Carolina at Chapel Hill.
19  *              Later tweaked by a couple of people on Usenet.  Completely
20  *              overhauled by Rich $alz <rsalz@osf.org> and Jim Berets
21  *              <jberets@bbn.com> in August, 1990.
22  *
23  *              Further revised (removed obsolete constructs and cleaned up
24  *              timezone names) in August, 1991, by Rich.
25  *              Paul Eggert <eggert@twinsun.com> helped in September 1992.
26  *              Roland Rosenfeld added MET DST code in April 1994.
27  *
28  *  Revision  : 1.13
29  *  Copyright : This code is in the public domain and has no copyright.
30  */
31 
32 /* SUPPRESS 530 */ /* Empty body for statement */
33 /* SUPPRESS 593 on yyerrlab */ /* Label was not used */
34 /* SUPPRESS 593 on yynewstate */ /* Label was not used */
35 /* SUPPRESS 595 on yypvt */ /* Automatic variable may be used before set */
36 
37 #undef alloca			/* conflicting def may be set by yacc */
38 #include <parsdate.h>
39 
40 /*
41 **  Get the number of elements in a fixed-size array, or a pointer just
42 **  past the end of it.
43 */
44 #define ENDOF(array)	(&array[ARRAY_SIZE(array)])
45 
46 #ifdef EBCDIC
47 #define TO_ASCII(c)	TOASCII(c)
48 #define TO_LOCAL(c)	FROMASCII(c)
49 #else
50 #define TO_ASCII(c)	(c)
51 #define TO_LOCAL(c)	(c)
52 #endif
53 
54 #define IS7BIT(x)		((unsigned) TO_ASCII(x) < 128)
55 #define CTYPE(isXXXXX, c)	(IS7BIT(c) && isXXXXX(((unsigned char)c)))
56 
57 typedef char *PD_STRING;
58 
59 extern int date_parse(void);
60 
61 #define yyparse		date_parse
62 #define yylex		date_lex
63 #define yyerror		date_error
64 
65     /* See the LeapYears table in Convert. */
66 #define EPOCH		1970
67 #define END_OF_TIME	2038
68 
69     /* Constants for general time calculations. */
70 #define DST_OFFSET	1
71 #define SECSPERDAY	(24L * 60L * 60L)
72     /* Readability for TABLE stuff. */
73 #define HOUR(x)		(x * 60)
74 
75 #define LPAREN		'('
76 #define RPAREN		')'
77 
78 /*
79 **  Daylight-savings mode:  on, off, or not yet known.
80 */
81 typedef enum _DSTMODE {
82     DSTon, DSToff, DSTmaybe
83 } DSTMODE;
84 
85 /*
86 **  Meridian:  am, pm, or 24-hour style.
87 */
88 typedef enum _MERIDIAN {
89     MERam, MERpm, MER24
90 } MERIDIAN;
91 
92 /*
93 **  Global variables.  We could get rid of most of them by using a yacc
94 **  union, but this is more efficient.  (This routine predates the
95 **  yacc %union construct.)
96 */
97 static char *yyInput;
98 static DSTMODE yyDSTmode;
99 static int yyHaveDate;
100 static int yyHaveRel;
101 static int yyHaveTime;
102 static time_t yyTimezone;
103 static time_t yyDay;
104 static time_t yyHour;
105 static time_t yyMinutes;
106 static time_t yyMonth;
107 static time_t yySeconds;
108 static time_t yyYear;
109 static MERIDIAN yyMeridian;
110 static time_t yyRelMonth;
111 static time_t yyRelSeconds;
112 
113 static time_t ToSeconds(time_t, time_t, time_t, MERIDIAN);
114 static time_t Convert(time_t, time_t, time_t, time_t, time_t, time_t,
115 		      MERIDIAN, DSTMODE);
116 static time_t DSTcorrect(time_t, time_t);
117 static time_t RelativeMonth(time_t, time_t);
118 static int LookupWord(char *, int);
119 static int date_lex(void);
120 static int GetTimeInfo(TIMEINFO * Now);
121 
122 /*
123  * The 'date_error()' function is declared here to work around a defect in
124  * bison 1.22, which redefines 'const' further down in this file, making it
125  * impossible to put a prototype here, and the function later.  We're using
126  * 'const' on the parameter to quiet gcc's -Wwrite-strings warning.
127  */
128 /*ARGSUSED*/
date_error(const char GCC_UNUSED * s)129 static void date_error(const char GCC_UNUSED *s)
130 {
131     /*NOTREACHED */
132 }
133 
134 %}
135 
136 %union {
137     time_t		Number;
138     enum _MERIDIAN	Meridian;
139 }
140 
141 %token	tDAY tDAYZONE tMERIDIAN tMONTH tMONTH_UNIT tSEC_UNIT tSNUMBER
142 %token	tUNUMBER tZONE tDST
143 
144 %type	<Number>	tDAYZONE tMONTH tMONTH_UNIT tSEC_UNIT
145 %type	<Number>	tSNUMBER tUNUMBER tZONE numzone zone
146 %type	<Meridian>	tMERIDIAN o_merid
147 
148 %%
149 
150 spec	: /* NULL */
151 	| spec item
152 	;
153 
154 item	: time {
155 	    yyHaveTime++;
156 #if	defined(lint)
157 	    /* I am compulsive about lint natterings... */
158 	    if (yyHaveTime == -1) {
159 		YYERROR;
160 	    }
161 #endif	/* defined(lint) */
162 	}
163 	| time zone {
164 	    yyHaveTime++;
165 	    yyTimezone = $2;
166 	}
167 	| date {
168 	    yyHaveDate++;
169 	}
170 	| both {
171 	    yyHaveDate++;
172 	    yyHaveTime++;
173 	}
174 	| both zone {
175 	    yyHaveDate++;
176 	    yyHaveTime++;
177 	    yyTimezone = $2;
178 	}
179 	| rel {
180 	    yyHaveRel = 1;
181 	}
182 	;
183 
184 time	: tUNUMBER o_merid {
185 	    if ($1 < 100) {
186 		yyHour = $1;
187 		yyMinutes = 0;
188 	    }
189 	    else {
190 		yyHour = $1 / 100;
191 		yyMinutes = $1 % 100;
192 	    }
193 	    yySeconds = 0;
194 	    yyMeridian = $2;
195 	}
196 	| tUNUMBER ':' tUNUMBER o_merid {
197 	    yyHour = $1;
198 	    yyMinutes = $3;
199 	    yySeconds = 0;
200 	    yyMeridian = $4;
201 	}
202 	| tUNUMBER ':' tUNUMBER numzone {
203 	    yyHour = $1;
204 	    yyMinutes = $3;
205 	    yyTimezone = $4;
206 	    yyMeridian = MER24;
207 	    yyDSTmode = DSToff;
208 	}
209 	| tUNUMBER ':' tUNUMBER ':' tUNUMBER o_merid {
210 	    yyHour = $1;
211 	    yyMinutes = $3;
212 	    yySeconds = $5;
213 	    yyMeridian = $6;
214 	}
215 	| tUNUMBER ':' tUNUMBER ':' tUNUMBER numzone {
216 	    yyHour = $1;
217 	    yyMinutes = $3;
218 	    yySeconds = $5;
219 	    yyTimezone = $6;
220 	    yyMeridian = MER24;
221 	    yyDSTmode = DSToff;
222 	}
223 	;
224 
225 zone	: tZONE {
226 	    $$ = $1;
227 	    yyDSTmode = DSToff;
228 	}
229 	| tDAYZONE {
230 	    $$ = $1;
231 	    yyDSTmode = DSTon;
232 	}
233 	| tDAYZONE tDST {
234 	    yyTimezone = $1;
235 	    yyDSTmode = DSTon;
236 	}
237 	| tZONE numzone {
238 	    /* Only allow "GMT+300" and "GMT-0800" */
239 	    if ($1 != 0) {
240 		YYABORT;
241 	    }
242 	    $$ = $2;
243 	    yyDSTmode = DSToff;
244 	}
245 	| numzone {
246 	    $$ = $1;
247 	    yyDSTmode = DSToff;
248 	}
249 	;
250 
251 numzone	: tSNUMBER {
252 	    int	i;
253 
254 	    /* Unix and GMT and numeric timezones -- a little confusing. */
255 	    if ((int)$1 < 0) {
256 		/* Don't work with negative modulus. */
257 		$1 = -(int)$1;
258 		if ($1 > 9999 || (i = (int) ($1 % 100)) >= 60) {
259 			YYABORT;
260 		}
261 		$$ = ($1 / 100) * 60 + i;
262 	    }
263 	    else {
264 		if ($1 > 9999 || (i = (int) ($1 % 100)) >= 60) {
265 			YYABORT;
266 		}
267 		$$ = -(($1 / 100) * 60 + i);
268 	    }
269 	}
270 	;
271 
272 date	: tUNUMBER '/' tUNUMBER {
273 	    yyMonth = $1;
274 	    yyDay = $3;
275 	}
276 	| tUNUMBER '/' tUNUMBER '/' tUNUMBER {
277 	    if ($1 > 100) {
278 		yyYear = $1;
279 		yyMonth = $3;
280 		yyDay = $5;
281 	    }
282 	    else {
283 		yyMonth = $1;
284 		yyDay = $3;
285 		yyYear = $5;
286 	    }
287 	}
288 	| tMONTH tUNUMBER {
289 	    yyMonth = $1;
290 	    yyDay = $2;
291 	}
292 	| tMONTH tUNUMBER ',' tUNUMBER {
293 	    yyMonth = $1;
294 	    yyDay = $2;
295 	    yyYear = $4;
296 	}
297 	| tUNUMBER tMONTH {
298 	    yyDay = $1;
299 	    yyMonth = $2;
300 	}
301 	| tUNUMBER tMONTH tUNUMBER {
302 	    yyDay = $1;
303 	    yyMonth = $2;
304 	    yyYear = $3;
305 	}
306 	| tDAY ',' tUNUMBER tMONTH tUNUMBER {
307 	    yyDay = $3;
308 	    yyMonth = $4;
309 	    yyYear = $5;
310 	}
311 	| tDAY ',' tUNUMBER '-' tMONTH tSNUMBER {
312 	    yyDay = $3;
313 	    yyMonth = $5;
314 	    yyYear = -$6;
315 	}
316 	| tUNUMBER tSNUMBER tSNUMBER {
317 	    yyDay = $1;
318 	    yyMonth = -$2;
319 	    yyYear = -$3;
320 	    yyDSTmode = DSToff;	/* assume midnight if no time given */
321 	    yyTimezone = 0;	/* Lynx assumes GMT for this format */
322 	}
323 	;
324 
325 both	: tDAY tMONTH tUNUMBER tUNUMBER ':' tUNUMBER ':' tUNUMBER tUNUMBER {
326 	    yyMonth = $2;
327 	    yyDay = $3;
328 	    yyYear = $9;
329 	    yyHour = $4;
330 	    yyMinutes = $6;
331 	    yySeconds = $8;
332 	}
333 	;
334 
335 rel	: tSNUMBER tSEC_UNIT {
336 	    yyRelSeconds += $1 * $2;
337 	}
338 	| tUNUMBER tSEC_UNIT {
339 	    yyRelSeconds += $1 * $2;
340 	}
341 	| tSNUMBER tMONTH_UNIT {
342 	    yyRelMonth += $1 * $2;
343 	}
344 	| tUNUMBER tMONTH_UNIT {
345 	    yyRelMonth += $1 * $2;
346 	}
347 	;
348 
349 o_merid	: /* NULL */ {
350 	    $$ = MER24;
351 	}
352 	| tMERIDIAN {
353 	    $$ = $1;
354 	}
355 	;
356 
357 %%
358 
359 
360 /*
361 **  An entry in the lexical lookup table.
362 */
363 /* *INDENT-OFF* */
364 typedef struct _TABLE {
365     const char *name;
366     int		type;
367     time_t	value;
368 } TABLE;
369 
370 /* Month and day table. */
371 static const TABLE MonthDayTable[] = {
372     { "january",	tMONTH,  1 },
373     { "february",	tMONTH,  2 },
374     { "march",		tMONTH,  3 },
375     { "april",		tMONTH,  4 },
376     { "may",		tMONTH,  5 },
377     { "june",		tMONTH,  6 },
378     { "july",		tMONTH,  7 },
379     { "august",		tMONTH,  8 },
380     { "september",	tMONTH,  9 },
381     { "october",	tMONTH, 10 },
382     { "november",	tMONTH, 11 },
383     { "december",	tMONTH, 12 },
384 	/* The value of the day isn't used... */
385     { "sunday",		tDAY, 0 },
386     { "monday",		tDAY, 0 },
387     { "tuesday",	tDAY, 0 },
388     { "wednesday",	tDAY, 0 },
389     { "thursday",	tDAY, 0 },
390     { "friday",		tDAY, 0 },
391     { "saturday",	tDAY, 0 },
392 };
393 
394 /* Time units table. */
395 static const TABLE	UnitsTable[] = {
396     { "year",		tMONTH_UNIT,	12 },
397     { "month",		tMONTH_UNIT,	1 },
398     { "week",		tSEC_UNIT,	7 * 24 * 60 * 60 },
399     { "day",		tSEC_UNIT,	1 * 24 * 60 * 60 },
400     { "hour",		tSEC_UNIT,	60 * 60 },
401     { "minute",		tSEC_UNIT,	60 },
402     { "min",		tSEC_UNIT,	60 },
403     { "second",		tSEC_UNIT,	1 },
404     { "sec",		tSEC_UNIT,	1 },
405 };
406 
407 /* Timezone table. */
408 static const TABLE	TimezoneTable[] = {
409     { "gmt",	tZONE,     HOUR( 0) },	/* Greenwich Mean */
410     { "ut",	tZONE,     HOUR( 0) },	/* Universal */
411     { "utc",	tZONE,     HOUR( 0) },	/* Universal Coordinated */
412     { "cut",	tZONE,     HOUR( 0) },	/* Coordinated Universal */
413     { "z",	tZONE,     HOUR( 0) },	/* Greenwich Mean */
414     { "wet",	tZONE,     HOUR( 0) },	/* Western European */
415     { "bst",	tDAYZONE,  HOUR( 0) },	/* British Summer */
416     { "nst",	tZONE,     HOUR(3)+30 }, /* Newfoundland Standard */
417     { "ndt",	tDAYZONE,  HOUR(3)+30 }, /* Newfoundland Daylight */
418     { "ast",	tZONE,     HOUR( 4) },	/* Atlantic Standard */
419     { "adt",	tDAYZONE,  HOUR( 4) },	/* Atlantic Daylight */
420     { "est",	tZONE,     HOUR( 5) },	/* Eastern Standard */
421     { "edt",	tDAYZONE,  HOUR( 5) },	/* Eastern Daylight */
422     { "cst",	tZONE,     HOUR( 6) },	/* Central Standard */
423     { "cdt",	tDAYZONE,  HOUR( 6) },	/* Central Daylight */
424     { "mst",	tZONE,     HOUR( 7) },	/* Mountain Standard */
425     { "mdt",	tDAYZONE,  HOUR( 7) },	/* Mountain Daylight */
426     { "pst",	tZONE,     HOUR( 8) },	/* Pacific Standard */
427     { "pdt",	tDAYZONE,  HOUR( 8) },	/* Pacific Daylight */
428     { "yst",	tZONE,     HOUR( 9) },	/* Yukon Standard */
429     { "ydt",	tDAYZONE,  HOUR( 9) },	/* Yukon Daylight */
430     { "akst",	tZONE,     HOUR( 9) },	/* Alaska Standard */
431     { "akdt",	tDAYZONE,  HOUR( 9) },	/* Alaska Daylight */
432     { "hst",	tZONE,     HOUR(10) },	/* Hawaii Standard */
433     { "hast",	tZONE,     HOUR(10) },	/* Hawaii-Aleutian Standard */
434     { "hadt",	tDAYZONE,  HOUR(10) },	/* Hawaii-Aleutian Daylight */
435     { "ces",	tDAYZONE,  -HOUR(1) },	/* Central European Summer */
436     { "cest",	tDAYZONE,  -HOUR(1) },	/* Central European Summer */
437     { "mez",	tZONE,     -HOUR(1) },	/* Middle European */
438     { "mezt",	tDAYZONE,  -HOUR(1) },	/* Middle European Summer */
439     { "cet",	tZONE,     -HOUR(1) },	/* Central European */
440     { "met",	tZONE,     -HOUR(1) },	/* Middle European */
441 /* Additional aliases for MET / MET DST *************************************/
442     { "mez",    tZONE,     -HOUR(1) },  /* Middle European */
443     { "mewt",   tZONE,     -HOUR(1) },  /* Middle European Winter */
444     { "mest",   tDAYZONE,  -HOUR(1) },  /* Middle European Summer */
445     { "mes",    tDAYZONE,  -HOUR(1) },  /* Middle European Summer */
446     { "mesz",   tDAYZONE,  -HOUR(1) },  /* Middle European Summer */
447     { "msz",    tDAYZONE,  -HOUR(1) },  /* Middle European Summer */
448     { "metdst", tDAYZONE,  -HOUR(1) },  /* Middle European Summer */
449 /****************************************************************************/
450     { "eet",	tZONE,     -HOUR(2) },	/* Eastern Europe */
451     { "msk",	tZONE,     -HOUR(3) },	/* Moscow Winter */
452     { "msd",	tDAYZONE,  -HOUR(3) },	/* Moscow Summer */
453     { "wast",	tZONE,     -HOUR(8) },	/* West Australian Standard */
454     { "wadt",	tDAYZONE,  -HOUR(8) },	/* West Australian Daylight */
455     { "hkt",	tZONE,     -HOUR(8) },	/* Hong Kong */
456     { "cct",	tZONE,     -HOUR(8) },	/* China Coast */
457     { "jst",	tZONE,     -HOUR(9) },	/* Japan Standard */
458     { "kst",	tZONE,     -HOUR(9) },	/* Korean Standard */
459     { "kdt",	tZONE,     -HOUR(9) },	/* Korean Daylight */
460     { "cast",	tZONE,     -(HOUR(9)+30) }, /* Central Australian Standard */
461     { "cadt",	tDAYZONE,  -(HOUR(9)+30) }, /* Central Australian Daylight */
462     { "east",	tZONE,     -HOUR(10) },	/* Eastern Australian Standard */
463     { "eadt",	tDAYZONE,  -HOUR(10) },	/* Eastern Australian Daylight */
464     { "nzst",	tZONE,     -HOUR(12) },	/* New Zealand Standard */
465     { "nzdt",	tDAYZONE,  -HOUR(12) },	/* New Zealand Daylight */
466 
467     /* For completeness we include the following entries. */
468 #if	0
469 
470     /* Duplicate names.  Either they conflict with a zone listed above
471      * (which is either more likely to be seen or just been in circulation
472      * longer), or they conflict with another zone in this section and
473      * we could not reasonably choose one over the other. */
474     { "fst",	tZONE,     HOUR( 2) },	/* Fernando De Noronha Standard */
475     { "fdt",	tDAYZONE,  HOUR( 2) },	/* Fernando De Noronha Daylight */
476     { "bst",	tZONE,     HOUR( 3) },	/* Brazil Standard */
477     { "est",	tZONE,     HOUR( 3) },	/* Eastern Standard (Brazil) */
478     { "edt",	tDAYZONE,  HOUR( 3) },	/* Eastern Daylight (Brazil) */
479     { "wst",	tZONE,     HOUR( 4) },	/* Western Standard (Brazil) */
480     { "wdt",	tDAYZONE,  HOUR( 4) },	/* Western Daylight (Brazil) */
481     { "cst",	tZONE,     HOUR( 5) },	/* Chile Standard */
482     { "cdt",	tDAYZONE,  HOUR( 5) },	/* Chile Daylight */
483     { "ast",	tZONE,     HOUR( 5) },	/* Acre Standard */
484     { "adt",	tDAYZONE,  HOUR( 5) },	/* Acre Daylight */
485     { "cst",	tZONE,     HOUR( 5) },	/* Cuba Standard */
486     { "cdt",	tDAYZONE,  HOUR( 5) },	/* Cuba Daylight */
487     { "est",	tZONE,     HOUR( 6) },	/* Easter Island Standard */
488     { "edt",	tDAYZONE,  HOUR( 6) },	/* Easter Island Daylight */
489     { "sst",	tZONE,     HOUR(11) },	/* Samoa Standard */
490     { "ist",	tZONE,     -HOUR(2) },	/* Israel Standard */
491     { "idt",	tDAYZONE,  -HOUR(2) },	/* Israel Daylight */
492     { "idt",	tDAYZONE,  -(HOUR(3)+30) }, /* Iran Daylight */
493     { "ist",	tZONE,     -(HOUR(3)+30) }, /* Iran Standard */
494     { "cst",	 tZONE,     -HOUR(8) },	/* China Standard */
495     { "cdt",	 tDAYZONE,  -HOUR(8) },	/* China Daylight */
496     { "sst",	 tZONE,     -HOUR(8) },	/* Singapore Standard */
497 
498     /* Dubious (e.g., not in Olson's TIMEZONE package) or obsolete. */
499     { "gst",	tZONE,     HOUR( 3) },	/* Greenland Standard */
500     { "wat",	tZONE,     -HOUR(1) },	/* West Africa */
501     { "at",	tZONE,     HOUR( 2) },	/* Azores */
502     { "gst",	tZONE,     -HOUR(10) },	/* Guam Standard */
503     { "nft",	tZONE,     HOUR(3)+30 }, /* Newfoundland */
504     { "idlw",	tZONE,     HOUR(12) },	/* International Date Line West */
505     { "mewt",	tZONE,     -HOUR(1) },	/* Middle European Winter */
506     { "mest",	tDAYZONE,  -HOUR(1) },	/* Middle European Summer */
507     { "swt",	tZONE,     -HOUR(1) },	/* Swedish Winter */
508     { "sst",	tDAYZONE,  -HOUR(1) },	/* Swedish Summer */
509     { "fwt",	tZONE,     -HOUR(1) },	/* French Winter */
510     { "fst",	tDAYZONE,  -HOUR(1) },	/* French Summer */
511     { "bt",	tZONE,     -HOUR(3) },	/* Baghdad */
512     { "it",	tZONE,     -(HOUR(3)+30) }, /* Iran */
513     { "zp4",	tZONE,     -HOUR(4) },	/* USSR Zone 3 */
514     { "zp5",	tZONE,     -HOUR(5) },	/* USSR Zone 4 */
515     { "ist",	tZONE,     -(HOUR(5)+30) }, /* Indian Standard */
516     { "zp6",	tZONE,     -HOUR(6) },	/* USSR Zone 5 */
517     { "nst",	tZONE,     -HOUR(7) },	/* North Sumatra */
518     { "sst",	tZONE,     -HOUR(7) },	/* South Sumatra */
519     { "jt",	tZONE,     -(HOUR(7)+30) }, /* Java (3pm in Cronusland!) */
520     { "nzt",	tZONE,     -HOUR(12) },	/* New Zealand */
521     { "idle",	tZONE,     -HOUR(12) },	/* International Date Line East */
522     { "cat",	tZONE,     HOUR(10) },	/* -- expired 1967 */
523     { "nt",	tZONE,     HOUR(11) },	/* -- expired 1967 */
524     { "ahst",	tZONE,     HOUR(10) },	/* -- expired 1983 */
525     { "hdt",	tDAYZONE,  HOUR(10) },	/* -- expired 1986 */
526 #endif	/* 0 */
527 };
528 /* *INDENT-ON* */
529 
ToSeconds(time_t Hours,time_t Minutes,time_t Seconds,MERIDIAN Meridian)530 static time_t ToSeconds(time_t Hours, time_t Minutes, time_t Seconds, MERIDIAN Meridian)
531 {
532     if ((long) Minutes < 0 || Minutes > 59 || (long) Seconds < 0 || Seconds > 61)
533 	return -1;
534     if (Meridian == MER24) {
535 	if ((long) Hours < 0 || Hours > 23)
536 	    return -1;
537     } else {
538 	if (Hours < 1 || Hours > 12)
539 	    return -1;
540 	if (Hours == 12)
541 	    Hours = 0;
542 	if (Meridian == MERpm)
543 	    Hours += 12;
544     }
545     return (Hours * 60L + Minutes) * 60L + Seconds;
546 }
547 
Convert(time_t Month,time_t Day,time_t Year,time_t Hours,time_t Minutes,time_t Seconds,MERIDIAN Meridian,DSTMODE dst)548 static time_t Convert(time_t Month, time_t Day, time_t Year, time_t Hours,
549 		      time_t Minutes, time_t Seconds, MERIDIAN Meridian,
550 		      DSTMODE dst)
551 {
552     static const int DaysNormal[13] =
553     {
554 	0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
555     };
556     static const int DaysLeap[13] =
557     {
558 	0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
559     };
560     static const int LeapYears[] =
561     {
562 	1972, 1976, 1980, 1984, 1988, 1992, 1996,
563 	2000, 2004, 2008, 2012, 2016, 2020, 2024, 2028, 2032, 2036
564     };
565     const int *yp;
566     const int *mp;
567     int i;
568     time_t Julian;
569     time_t tod;
570 
571     if ((long) Year < 0)
572 	Year = -Year;
573     if (Year < 70)
574 	Year += 2000;
575     if (Year < 100)
576 	Year += 1900;
577     if (Year < EPOCH)
578 	Year += 100;
579     for (mp = DaysNormal, yp = LeapYears; yp < ENDOF(LeapYears); yp++)
580 	if (Year == *yp) {
581 	    mp = DaysLeap;
582 	    break;
583 	}
584     if (Year < EPOCH || Year > END_OF_TIME
585 	|| Month < 1 || Month > 12
586     /* NOSTRICT */
587     /* conversion from long may lose accuracy */
588 	|| Day < 1 || Day > mp[(int) Month]) {
589 	return -1;
590     }
591 
592     Julian = Day - 1 + (Year - EPOCH) * 365;
593     for (yp = LeapYears; yp < ENDOF(LeapYears); yp++, Julian++) {
594 	if (Year <= *yp)
595 	    break;
596     }
597     for (i = 1; i < Month; i++)
598 	Julian += *++mp;
599     Julian *= SECSPERDAY;
600     Julian += yyTimezone * 60L;
601     if ((long) (tod = ToSeconds(Hours, Minutes, Seconds, Meridian)) < 0) {
602 	return -1;
603     }
604     Julian += tod;
605     tod = Julian;
606     if (dst == DSTon || (dst == DSTmaybe && localtime(&tod)->tm_isdst))
607 	Julian -= DST_OFFSET * 60 * 60;
608     return Julian;
609 }
610 
DSTcorrect(time_t Start,time_t Future)611 static time_t DSTcorrect(time_t Start, time_t Future)
612 {
613     time_t StartDay;
614     time_t FutureDay;
615 
616     StartDay = (localtime(&Start)->tm_hour + 1) % 24;
617     FutureDay = (localtime(&Future)->tm_hour + 1) % 24;
618     return (Future - Start) + (StartDay - FutureDay) * DST_OFFSET * 60 * 60;
619 }
620 
RelativeMonth(time_t Start,time_t RelMonth)621 static time_t RelativeMonth(time_t Start, time_t RelMonth)
622 {
623     struct tm *tm;
624     time_t Month;
625     time_t Year;
626 
627     tm = localtime(&Start);
628     Month = 12 * tm->tm_year + tm->tm_mon + RelMonth;
629     Year = Month / 12 + 1900;
630     Month = Month % 12 + 1;
631     return DSTcorrect(Start,
632 		      Convert(Month, (time_t) tm->tm_mday, Year,
633 			      (time_t) tm->tm_hour, (time_t) tm->tm_min,
634 			      (time_t) tm->tm_sec,
635 			      MER24, DSTmaybe));
636 }
637 
LookupWord(char * buff,int length)638 static int LookupWord(char *buff,
639 		      int length)
640 {
641     char *p;
642     const char *q;
643     const TABLE *tp;
644     int c;
645 
646     p = buff;
647     c = p[0];
648 
649     /* See if we have an abbreviation for a month. */
650     if (length == 3 || (length == 4 && p[3] == '.')) {
651 	for (tp = MonthDayTable; tp < ENDOF(MonthDayTable); tp++) {
652 	    q = tp->name;
653 	    if (c == q[0] && p[1] == q[1] && p[2] == q[2]) {
654 		yylval.Number = tp->value;
655 		return tp->type;
656 	    }
657 	}
658     } else {
659 	for (tp = MonthDayTable; tp < ENDOF(MonthDayTable); tp++) {
660 	    if (c == tp->name[0] && strcmp(p, tp->name) == 0) {
661 		yylval.Number = tp->value;
662 		return tp->type;
663 	    }
664 	}
665     }
666 
667     /* Try for a timezone. */
668     for (tp = TimezoneTable; tp < ENDOF(TimezoneTable); tp++) {
669 	if (c == tp->name[0] && p[1] == tp->name[1]
670 	    && strcmp(p, tp->name) == 0) {
671 	    yylval.Number = tp->value;
672 	    return tp->type;
673 	}
674     }
675 
676     if (strcmp(buff, "dst") == 0)
677 	return tDST;
678 
679     /* Try the units table. */
680     for (tp = UnitsTable; tp < ENDOF(UnitsTable); tp++) {
681 	if (c == tp->name[0] && strcmp(p, tp->name) == 0) {
682 	    yylval.Number = tp->value;
683 	    return tp->type;
684 	}
685     }
686 
687     /* Strip off any plural and try the units table again. */
688     if (--length > 0 && p[length] == 's') {
689 	p[length] = '\0';
690 	for (tp = UnitsTable; tp < ENDOF(UnitsTable); tp++) {
691 	    if (c == tp->name[0] && strcmp(p, tp->name) == 0) {
692 		p[length] = 's';
693 		yylval.Number = tp->value;
694 		return tp->type;
695 	    }
696 	}
697 	p[length] = 's';
698     }
699     length++;
700 
701     /* Drop out any periods. */
702     for (p = buff, q = (PD_STRING) buff; *q; q++) {
703 	if (*q != '.')
704 	    *p++ = *q;
705     }
706     *p = '\0';
707 
708     /* Try the meridians. */
709     if (buff[1] == 'm' && buff[2] == '\0') {
710 	if (buff[0] == 'a') {
711 	    yylval.Meridian = MERam;
712 	    return tMERIDIAN;
713 	}
714 	if (buff[0] == 'p') {
715 	    yylval.Meridian = MERpm;
716 	    return tMERIDIAN;
717 	}
718     }
719 
720     /* If we saw any periods, try the timezones again. */
721     if (p - buff != length) {
722 	c = buff[0];
723 	for (p = buff, tp = TimezoneTable; tp < ENDOF(TimezoneTable); tp++) {
724 	    if (c == tp->name[0] && p[1] == tp->name[1]
725 		&& strcmp(p, tp->name) == 0) {
726 		yylval.Number = tp->value;
727 		return tp->type;
728 	    }
729 	}
730     }
731 
732     /* Unknown word -- assume GMT timezone. */
733     yylval.Number = 0;
734     return tZONE;
735 }
736 
737 /*
738  * This returns characters as-is (the ones that are not part of some token),
739  * and codes greater than 256 (the token values).
740  *
741  * yacc generates tables that may use the character value.  In particular,
742  * byacc's yycheck[] table contains integer values for the expected codes from
743  * this function, which (unless byacc is run locally) are ASCII codes.
744  *
745  * The TO_LOCAL() function assumes its input is in ASCII, and the output is
746  * whatever native encoding is used on the machine, e.g., EBCDIC.
747  *
748  * The TO_ASCII() function is the inverse of TO_LOCAL().
749  */
date_lex(void)750 static int date_lex(void)
751 {
752     int c;
753     char *p;
754     char buff[20];
755     int sign;
756     int i;
757     int nesting;
758 
759     /* Get first character after the whitespace. */
760     for (;;) {
761 	while (CTYPE(isspace, *yyInput))
762 	    yyInput++;
763 	c = *yyInput;
764 
765 	/* Ignore RFC 822 comments, typically time zone names. */
766 	if (c != LPAREN)
767 	    break;
768 	for (nesting = 1;
769 	     (c = *++yyInput) != RPAREN || --nesting;
770 	    ) {
771 	    if (c == LPAREN) {
772 		nesting++;
773 	    } else if (!IS7BIT(c) || c == '\0' || c == '\r'
774 		       || (c == '\\'
775 			   && ((c = *++yyInput) == '\0'
776 			       || !IS7BIT(c)))) {
777 		/* Lexical error: bad comment. */
778 		return '?';
779 	    }
780 	}
781 	yyInput++;
782     }
783 
784     /* A number? */
785     if (CTYPE(isdigit, c) || c == '-' || c == '+') {
786 	if (c == '-' || c == '+') {
787 	    sign = c == '-' ? -1 : 1;
788 	    yyInput++;
789 	    if (!CTYPE(isdigit, *yyInput)) {
790 		/* Return the isolated plus or minus sign. */
791 		--yyInput;
792 		return *yyInput++;
793 	    }
794 	} else {
795 	    sign = 0;
796 	}
797 	for (p = buff;
798 	     (c = *yyInput++) != '\0' && CTYPE(isdigit, c);
799 	    ) {
800 	    if (p < &buff[sizeof buff - 1])
801 		*p++ = (char) c;
802 	}
803 	*p = '\0';
804 	i = atoi(buff);
805 
806 	yyInput--;
807 	yylval.Number = sign < 0 ? -i : i;
808 	return sign ? tSNUMBER : tUNUMBER;
809     }
810 
811     /* A word? */
812     if (CTYPE(isalpha, c)) {
813 	for (p = buff;
814 	     (c = *yyInput++) == '.' || CTYPE(isalpha, c);
815 	    ) {
816 	    if (p < &buff[sizeof buff - 1])
817 		*p++ = (char) (CTYPE(isupper, c) ? tolower(c) : c);
818 	}
819 	*p = '\0';
820 	yyInput--;
821 	return LookupWord(buff, (int) (p - buff));
822     }
823 
824     return *yyInput++;
825 }
826 
GetTimeInfo(TIMEINFO * Now)827 static int GetTimeInfo(TIMEINFO * Now)
828 {
829     static time_t LastTime;
830     static long LastTzone;
831     struct tm *tm;
832 
833 #if	defined(HAVE_GETTIMEOFDAY)
834     struct timeval tv;
835 #endif /* defined(HAVE_GETTIMEOFDAY) */
836 #if	defined(DONT_HAVE_TM_GMTOFF)
837     struct tm local;
838     struct tm gmt;
839 #endif /* !defined(DONT_HAVE_TM_GMTOFF) */
840 
841     /* Get the basic time. */
842 #if defined(HAVE_GETTIMEOFDAY)
843     if (gettimeofday(&tv, (struct timezone *) NULL) == -1)
844 	return -1;
845     Now->time = tv.tv_sec;
846     Now->usec = tv.tv_usec;
847 #else
848     /* Can't check for -1 since that might be a time, I guess. */
849     (void) time(&Now->time);
850     Now->usec = 0;
851 #endif /* defined(HAVE_GETTIMEOFDAY) */
852 
853     /* Now get the timezone if it's been an hour since the last time. */
854     if (Now->time - LastTime > 60 * 60) {
855 	LastTime = Now->time;
856 	if ((tm = localtime(&Now->time)) == NULL)
857 	    return -1;
858 #if	defined(DONT_HAVE_TM_GMTOFF)
859 	/* To get the timezone, compare localtime with GMT. */
860 	local = *tm;
861 	if ((tm = gmtime(&Now->time)) == NULL)
862 	    return -1;
863 	gmt = *tm;
864 
865 	/* Assume we are never more than 24 hours away. */
866 	LastTzone = gmt.tm_yday - local.tm_yday;
867 	if (LastTzone > 1)
868 	    LastTzone = -24;
869 	else if (LastTzone < -1)
870 	    LastTzone = 24;
871 	else
872 	    LastTzone *= 24;
873 
874 	/* Scale in the hours and minutes; ignore seconds. */
875 	LastTzone += gmt.tm_hour - local.tm_hour;
876 	LastTzone *= 60;
877 	LastTzone += gmt.tm_min - local.tm_min;
878 #else
879 	LastTzone = (0 - tm->tm_gmtoff) / 60;
880 #endif /* defined(DONT_HAVE_TM_GMTOFF) */
881     }
882     Now->tzone = LastTzone;
883     return 0;
884 }
885 
parsedate(char * p,TIMEINFO * now)886 time_t parsedate(char *p,
887 		 TIMEINFO * now)
888 {
889     struct tm *tm;
890     TIMEINFO ti;
891     time_t Start;
892 
893     yyInput = p;
894     if (now == NULL) {
895 	now = &ti;
896 	(void) GetTimeInfo(&ti);
897     }
898 
899     tm = localtime(&now->time);
900     yyYear = tm->tm_year + 1900;
901     yyMonth = tm->tm_mon + 1;
902     yyDay = tm->tm_mday;
903     yyTimezone = now->tzone;
904     if (tm->tm_isdst)		/* Correct timezone offset for DST */
905 	yyTimezone += DST_OFFSET * 60;
906     yyDSTmode = DSTmaybe;
907     yyHour = 0;
908     yyMinutes = 0;
909     yySeconds = 0;
910     yyMeridian = MER24;
911     yyRelSeconds = 0;
912     yyRelMonth = 0;
913     yyHaveDate = 0;
914     yyHaveRel = 0;
915     yyHaveTime = 0;
916 
917     if (date_parse() || yyHaveTime > 1 || yyHaveDate > 1)
918 	return -1;
919 
920     if (yyHaveDate || yyHaveTime) {
921 	Start = Convert(yyMonth, yyDay, yyYear, yyHour, yyMinutes, yySeconds,
922 			yyMeridian, yyDSTmode);
923 	if ((long) Start < 0)
924 	    return -1;
925     } else {
926 	Start = now->time;
927 	if (!yyHaveRel)
928 	    Start -= (tm->tm_hour * 60L + tm->tm_min) * 60L + tm->tm_sec;
929     }
930 
931     Start += yyRelSeconds;
932     if (yyRelMonth)
933 	Start += RelativeMonth(Start, yyRelMonth);
934 
935     /* Have to do *something* with a legitimate -1 so it's distinguishable
936      * from the error return value.  (Alternately could set errno on error.) */
937     return (Start == (time_t) -1) ? 0 : Start;
938 }
939