merge with 1.8.1 + partial --version and --help

[gnulib.git] / lib / getdate.y

diff --git a/lib/getdate.y b/lib/getdate.y
index 4d2af5c..cdc2b55 100644 (file)
--- a/lib/getdate.y
+++ b/lib/getdate.y
@@ -1,6 +1,5 @@
 %{
-/* $Revision: 1.2 $
-**
+/*
 **  Originally written by Steven M. Bellovin <smb@research.att.com> while
 **  at the University of North Carolina at Chapel Hill.  Later tweaked by
 **  a couple of people on Usenet.  Completely overhauled by Rich $alz
@@ -18,7 +17,18 @@
 #include "config.h"
 #endif
 
+/* Since the code of getdate.y is not included in the Emacs executable
+   itself, there is no need to #define static in this file.  Even if
+   the code were included in the Emacs executable, it probably
+   wouldn't do any harm to #undef it here; this will only cause
+   problems if we try to write to a static variable, which I don't
+   think this code needs to do.  */
+#ifdef emacs
+#undef static
+#endif
+
 #ifdef __GNUC__
+#undef alloca
 #define alloca __builtin_alloca
 #else
 #ifdef HAVE_ALLOCA_H
@@ -49,33 +59,36 @@ char *alloca ();
 
 #include <sys/types.h>
 
-#if sgi
-#undef timezone
-#endif
-
-#if !(defined (USG) || defined (sgi) || defined (__386BSD__)) || defined(BSD4_2) || defined(BSD4_1C) || (defined (hp9000) && !defined (hpux)) || defined(_AIX) 
+#ifdef TIME_WITH_SYS_TIME
+#include <sys/time.h>
+#include <time.h>
+#else
+#ifdef HAVE_SYS_TIME_H
 #include <sys/time.h>
 #else
 #include <time.h>
 #endif
+#endif
 
-#if    defined(USG) || !defined(HAVE_FTIME)
+#ifdef timezone
+#undef timezone /* needed for sgi */
+#endif
+
+#if defined(HAVE_SYS_TIMEB_H) || (!defined(USG) && defined(HAVE_FTIME))
+#include <sys/timeb.h>
+#else
 /*
-**  If you need to do a tzset() call to set the
-**  timezone, and don't have ftime().
+** We use the obsolete `struct timeb' as part of our interface!
+** Since the system doesn't have it, we define it here;
+** our callers must do likewise.
 */
 struct timeb {
     time_t             time;           /* Seconds since the epoch      */
     unsigned short     millitm;        /* Field not used               */
-    short              timezone;
+    short              timezone;       /* Minutes west of GMT          */
     short              dstflag;        /* Field not used               */
 };
-
-#else
-
-#include <sys/timeb.h>
-
-#endif /* defined(USG) && !defined(HAVE_FTIME) */
+#endif /* defined(HAVE_SYS_TIMEB_H) */
 
 #endif /* defined(vms) */
 
@@ -83,6 +96,14 @@ struct timeb {
 #include <string.h>
 #endif
 
+/* Some old versions of bison generate parsers that use bcopy.
+   That loses on systems that don't provide the function, so we have
+   to redefine it here.  */
+#if !defined (HAVE_BCOPY) && defined (HAVE_MEMCPY) && !defined (bcopy)
+#define bcopy(from, to, len) memcpy ((to), (from), (len))
+#endif
+
+extern struct tm       *gmtime();
 extern struct tm       *localtime();
 
 #define yyparse getdate_yyparse
@@ -94,7 +115,7 @@ static int yyerror ();
 
 #if    !defined(lint) && !defined(SABER)
 static char RCS[] =
-       "$Header: /w/src/cvsroot/fileutils/lib/getdate.y,v 1.2 1993/04/04 15:21:49 meyering Exp $";
+       "$Header: str2date.y,v 2.1 90/09/06 08:15:06 cronan Exp $";
 #endif /* !defined(lint) && !defined(SABER) */
 
 
@@ -847,12 +868,38 @@ yylex()
 }
 
 
+#define TM_YEAR_ORIGIN 1900
+
+/* Yield A - B, measured in seconds.  */
+static time_t
+difftm(a, b)
+     struct tm *a, *b;
+{
+  int ay = a->tm_year + (TM_YEAR_ORIGIN - 1);
+  int by = b->tm_year + (TM_YEAR_ORIGIN - 1);
+  return
+    (
+     (
+      (
+       /* difference in day of year */
+       a->tm_yday - b->tm_yday
+       /* + intervening leap days */
+       +  ((ay >> 2) - (by >> 2))
+       -  (ay/100 - by/100)
+       +  ((ay/100 >> 2) - (by/100 >> 2))
+       /* + difference in years * 365 */
+       +  (time_t)(ay-by) * 365
+       )*24 + (a->tm_hour - b->tm_hour)
+      )*60 + (a->tm_min - b->tm_min)
+     )*60 + (a->tm_sec - b->tm_sec);
+}
+
 time_t
 get_date(p, now)
     char               *p;
     struct timeb       *now;
 {
-    struct tm          *tm;
+    struct tm          *tm, gmt;
     struct timeb       ftz;
     time_t             Start;
     time_t             tod;
@@ -860,34 +907,12 @@ get_date(p, now)
     yyInput = p;
     if (now == NULL) {
         now = &ftz;
-#if    !defined(HAVE_FTIME)
        (void)time(&ftz.time);
-       /* Set the timezone global. */
-       tzset();
-       {
-#if sgi
-           ftz.timezone = (int) _timezone / 60;
-#else /* not sgi */
-#ifdef __386BSD__
-           ftz.timezone = 0;
-#else /* neither sgi nor 386BSD */
-#if defined (USG)
-           extern time_t timezone;
-
-           ftz.timezone = (int) timezone / 60;
-#else /* neither sgi nor 386BSD nor USG */
-           struct timeval tv;
-           struct timezone tz;
-
-           gettimeofday (&tv, &tz);
-           ftz.timezone = (int) tz.tz_minuteswest;
-#endif /* neither sgi nor 386BSD nor USG */
-#endif /* neither sgi nor 386BSD */
-#endif /* not sgi */
-       }
-#else /* HAVE_FTIME */
-       (void)ftime(&ftz);
-#endif /* HAVE_FTIME */
+
+       if (! (tm = gmtime (&ftz.time)))
+           return -1;
+       gmt = *tm;      /* Make a copy, in case localtime modifies *tm.  */
+       ftz.timezone = difftm (&gmt, localtime (&ftz.time)) / 60;
     }
 
     tm = localtime(&now->time);