[src/trunk]: src/lib/libutil Use mktime(3) instead of hand-coded equivalent.

[apb <apb%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/1229e11836f1
branches:  trunk
changeset: 772089:1229e11836f1
user:      apb <apb%NetBSD.org@localhost>
date:      Sat Dec 17 19:14:10 2011 +0000

description:
Use mktime(3) instead of hand-coded equivalent.
Don't treat negative results as errors (we should be able
to handle years before 1970).

XXX: This still fails on 1969-12-31 23:59:59.

diffstat:

 lib/libutil/parsedate.y |  125 +++++++++--------------------------------------
 1 files changed, 24 insertions(+), 101 deletions(-)

diffs (159 lines):

diff -r 3ec3f32a986c -r 1229e11836f1 lib/libutil/parsedate.y
--- a/lib/libutil/parsedate.y   Sat Dec 17 19:07:34 2011 +0000
+++ b/lib/libutil/parsedate.y   Sat Dec 17 19:14:10 2011 +0000
@@ -573,69 +573,24 @@
 }
 
 
-static time_t
-ToSeconds(
-    time_t     Hours,
-    time_t     Minutes,
-    time_t     Seconds,
-    MERIDIAN   Meridian
-)
-{
-    if (Minutes < 0 || Minutes > 59 || Seconds < 0 || Seconds > 59)
-       return -1;
-    switch (Meridian) {
-    case MER24:
-       if (Hours < 0 || Hours > 23)
-           return -1;
-       return (Hours * 60L + Minutes) * 60L + Seconds;
-    case MERam:
-       if (Hours < 1 || Hours > 12)
-           return -1;
-       if (Hours == 12)
-           Hours = 0;
-       return (Hours * 60L + Minutes) * 60L + Seconds;
-    case MERpm:
-       if (Hours < 1 || Hours > 12)
-           return -1;
-       if (Hours == 12)
-           Hours = 0;
-       return ((Hours + 12) * 60L + Minutes) * 60L + Seconds;
-    default:
-       abort ();
-    }
-    /* NOTREACHED */
-}
-
-static int
-isLeap(int year)
-{
-    return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
-}
-
-
 /* Year is either
    * A negative number, which means to use its absolute value (why?)
    * A number from 0 to 99, which means a year from 1900 to 1999, or
    * The actual year (>=100).  */
 static time_t
 Convert(
-    time_t     Month,
-    time_t     Day,
-    time_t     Year,
-    time_t     Hours,
-    time_t     Minutes,
-    time_t     Seconds,
-    time_t     Timezone,
-    MERIDIAN   Meridian,
-    DSTMODE    DSTmode
+    time_t     Month,          /* month of year [1-12] */
+    time_t     Day,            /* day of month [1-31] */
+    time_t     Year,           /* year; see above comment */
+    time_t     Hours,          /* Hour of day [0-24] */
+    time_t     Minutes,        /* Minute of hour [0-59] */
+    time_t     Seconds,        /* Second of minute [0-60] */
+    time_t     Timezone,       /* Timezone as seconds west of UTC */
+    MERIDIAN   Meridian,       /* Hours are am/pm/24 hour clock */
+    DSTMODE    DSTmode         /* DST on/off/maybe */
 )
 {
-    static int DaysInMonth[12] = {
-       31, 0, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
-    };
-    time_t     tod;
-    time_t     Julian, oJulian;
-    int                i;
+    struct tm tm;
 
     /* XXX Y2K */
     if (Year < 0)
@@ -644,53 +599,21 @@
        Year += 2000;
     else if (Year < 100)
        Year += 1900;
-    DaysInMonth[1] = isLeap(Year) ? 29 : 28;
-    if (Year < EPOCH || Month < 1 || Month > 12
-     /* Lint fluff:  "conversion from long may lose accuracy" */
-     || Day < 1 || Day > DaysInMonth[(int)--Month])
-       /* FIXME:
-        * It would be nice to set a global error string here.
-        * "February 30 is not a valid date" is much more informative than
-        * "Can't parse date/time: 100 months" when the user input was
-        * "100 months" and addition resolved that to February 30, for
-        * example.  See rcs2-7 in src/sanity.sh for more. */
-       return -1;
-
-    for (Julian = Day - 1, i = 0; i < Month; i++)
-       Julian += DaysInMonth[i];
-
-    oJulian = Julian;
-    for (i = EPOCH; i < Year; i++) {
-       Julian += 365 + isLeap(i);
-       if (oJulian > Julian)
-           return -1;
-       oJulian = Julian;
-    }
 
-    Julian *= SECSPERDAY;
-    if (oJulian > Julian)
-       return -1;
-    oJulian = Julian;
-    Julian += Timezone * 60L;
-    if (Timezone > 0 && oJulian > Julian)
-       return -1;
-    oJulian = Julian;
-
-    if ((tod = ToSeconds(Hours, Minutes, Seconds, Meridian)) < 0)
-       return -1;
+    tm.tm_sec = Seconds;
+    tm.tm_min = Minutes;
+    tm.tm_hour = Hours + (Meridian == MERpm ? 12 : 0);
+    tm.tm_mday = Day;
+    tm.tm_mon = Month - 1;
+    tm.tm_year = Year - 1900;
+    switch (DSTmode) {
+    case DSTon:  tm.tm_isdst = 1; break;
+    case DSToff: tm.tm_isdst = 0; break;
+    default:     tm.tm_isdst = -1; break;
+    }
+    tm.tm_gmtoff = -Timezone;
 
-    Julian += tod;
-    if (oJulian > Julian)
-       return -1;
-
-    if (DSTmode == DSTon || (DSTmode == DSTmaybe)) {
-       struct tm  *tm;
-       if ((tm = localtime(&Julian)) == NULL)
-           return -1;
-       if (tm->tm_isdst)
-           Julian -= 60 * 60;
-    }
-    return Julian;
+    return mktime(&tm);
 }
 
 
@@ -1008,7 +931,7 @@
        Start = Convert(param.yyMonth, param.yyDay, param.yyYear, param.yyHour,
            param.yyMinutes, param.yySeconds, param.yyTimezone,
            param.yyMeridian, param.yyDSTmode);
-       if (Start < 0)
+       if (Start == -1)
            return -1;
     }
     else {