[src/trunk]: src/lib/libutil Some years don't need the "maybe add 1900 or 200...

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

details:   https://anonhg.NetBSD.org/src/rev/6093baf1d2e1
branches:  trunk
changeset: 332761:6093baf1d2e1
user:      apb <apb%NetBSD.org@localhost>
date:      Tue Oct 07 22:27:14 2014 +0000

description:
Some years don't need the "maybe add 1900 or 2000" adjustment
that was designed for handling two-digit abbreviated years.
For example, "1/2/70" still refers to the year 1970, as before,
but "70-01-02" now refers to the year 70.

* Add a new yyHaveFullYear member to struct dateinfo, to record whether
  or not the year needs to be adjusted.
* Code that parses years sets yyHaveFullYear=1 if they know that the
  year should not be adjusted (as is the case for ISO 8601 dates), or if
  they perform their own adjustment (as is the case for CVS timestamps).
* Move the year adjustment code into a new function, AdjustYear,
  instead of inline in Convert().
* Make Convert() assume the year doesn't need to be adjusted,
  and make Convert's callers first call AdjustYear() if appropriate.

diffstat:

 lib/libutil/parsedate.y |  64 +++++++++++++++++++++++++++++++-----------------
 1 files changed, 41 insertions(+), 23 deletions(-)

diffs (141 lines):

diff -r 6eee553423dc -r 6093baf1d2e1 lib/libutil/parsedate.y
--- a/lib/libutil/parsedate.y   Tue Oct 07 22:20:33 2014 +0000
+++ b/lib/libutil/parsedate.y   Tue Oct 07 22:27:14 2014 +0000
@@ -14,7 +14,7 @@
 
 #include <sys/cdefs.h>
 #ifdef __RCSID
-__RCSID("$NetBSD: parsedate.y,v 1.16 2013/06/12 01:46:07 yamt Exp $");
+__RCSID("$NetBSD: parsedate.y,v 1.17 2014/10/07 22:27:14 apb Exp $");
 #endif
 
 #include <stdio.h>
@@ -69,22 +69,24 @@
 
 
 struct dateinfo {
-       DSTMODE yyDSTmode;
+       DSTMODE yyDSTmode;      /* DST on/off/maybe */
        time_t  yyDayOrdinal;
        time_t  yyDayNumber;
        int     yyHaveDate;
+       int     yyHaveFullYear; /* if true, year is not abbreviated. */
+                               /* if false, need to call AdjustYear(). */
        int     yyHaveDay;
        int     yyHaveRel;
        int     yyHaveTime;
        int     yyHaveZone;
-       time_t  yyTimezone;
-       time_t  yyDay;
-       time_t  yyHour;
-       time_t  yyMinutes;
-       time_t  yyMonth;
-       time_t  yySeconds;
-       time_t  yyYear;
-       MERIDIAN        yyMeridian;
+       time_t  yyTimezone;     /* Timezone as minutes ahead/east of UTC */
+       time_t  yyDay;          /* Day of month [1-31] */
+       time_t  yyHour;         /* Hour of day [0-24] or [1-12] */
+       time_t  yyMinutes;      /* Minute of hour [0-59] */
+       time_t  yyMonth;        /* Month of year [1-12] */
+       time_t  yySeconds;      /* Second of minute [0-60] */
+       time_t  yyYear;         /* Year, see also yyHaveFullYear */
+       MERIDIAN yyMeridian;    /* Interpret yyHour as AM/PM/24 hour clock */
        time_t  yyRelMonth;
        time_t  yyRelSeconds;
 };
@@ -144,6 +146,7 @@
 cvsstamp: tUNUMBER '.' tUNUMBER '.' tUNUMBER '.' tUNUMBER '.' tUNUMBER '.' tUNUMBER {
            param->yyYear = $1;
            if (param->yyYear < 100) param->yyYear += 1900;
+           param->yyHaveFullYear = 1;
            param->yyMonth = $3;
            param->yyDay = $5;
            param->yyHour = $7;
@@ -174,6 +177,7 @@
                param->yyMinutes = 0;
                param->yySeconds = 0;
            }
+           param->yyHaveFullYear = 1;
            param->yyDSTmode = DSToff;
            param->yyTimezone = 0;
        }
@@ -272,6 +276,7 @@
        | tUNUMBER tSNUMBER tSNUMBER {
            /* ISO 8601 format.  yyyy-mm-dd.  */
            param->yyYear = $1;
+           param->yyHaveFullYear = 1;
            param->yyMonth = -$2;
            param->yyDay = -$3;
        }
@@ -581,15 +586,31 @@
 }
 
 
-/* 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).  */
+/* Adjust year from a value that might be abbreviated, to a full value.
+ * e.g. convert 70 to 1970.
+ * Input 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).
+ * Returns the full year. */
+static time_t
+AdjustYear(time_t Year)
+{
+    /* XXX Y2K */
+    if (Year < 0)
+       Year = -Year;
+    if (Year < 70)
+       Year += 2000;
+    else if (Year < 100)
+       Year += 1900;
+    return Year;
+}
+
 static time_t
 Convert(
     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     Year,           /* year, not abbreviated in any way */
     time_t     Hours,          /* Hour of day [0-24] */
     time_t     Minutes,        /* Minute of hour [0-59] */
     time_t     Seconds,        /* Second of minute [0-60] */
@@ -601,14 +622,6 @@
     struct tm tm = {.tm_sec = 0};
     time_t result;
 
-    /* XXX Y2K */
-    if (Year < 0)
-       Year = -Year;
-    if (Year < 70)
-       Year += 2000;
-    else if (Year < 100)
-       Year += 1900;
-
     tm.tm_sec = Seconds;
     tm.tm_min = Minutes;
     tm.tm_hour = Hours + (Meridian == MERpm ? 12 : 0);
@@ -933,6 +946,7 @@
     param.yyRelSeconds = 0;
     param.yyRelMonth = 0;
     param.yyHaveDate = 0;
+    param.yyHaveFullYear = 0;
     param.yyHaveDay = 0;
     param.yyHaveRel = 0;
     param.yyHaveTime = 0;
@@ -945,6 +959,10 @@
     }
 
     if (param.yyHaveDate || param.yyHaveTime || param.yyHaveDay) {
+       if (! param.yyHaveFullYear) {
+               param.yyYear = AdjustYear(param.yyYear);
+               param.yyHaveFullYear = 1;
+       }
        Start = Convert(param.yyMonth, param.yyDay, param.yyYear, param.yyHour,
            param.yyMinutes, param.yySeconds, param.yyTimezone,
            param.yyMeridian, param.yyDSTmode);