[PATCH v2 1/4] time: Use __tz_convert in mktime implementation
Florian Weimer
fweimer@redhat.com
Thu Jan 2 17:42:31 GMT 2025
This replaces calls to convert_time and changes the signature
of __mktime_internal to accept a flag instead of a conversion
function.
---
time/mktime-internal.h | 23 +++++++++-------
time/mktime.c | 59 +++++++++++++++++-------------------------
time/timegm.c | 2 +-
3 files changed, 38 insertions(+), 46 deletions(-)
diff --git a/time/mktime-internal.h b/time/mktime-internal.h
index 5fbcc0ec60..64dc35b3cf 100644
--- a/time/mktime-internal.h
+++ b/time/mktime-internal.h
@@ -51,6 +51,15 @@ typedef int mktime_offset_t;
#endif
#ifndef _LIBC
+/* Convert T to a struct tm value in *TM. Use local time if USE_LOCAL.
+ T must be in range for __time64_t. Return TM if successful, NULL
+ (setting errno) on failure. */
+static inline struct tm *
+tz_convert (long_int t, bool use_local, struct tm *tm)
+{
+ return (use_local ? localtime_r : gmtime_r) (&t, tm);
+}
+
/* Although glibc source code uses leading underscores, Gnulib wants
ordinary names.
@@ -61,19 +70,13 @@ typedef int mktime_offset_t;
Similarly for gmtime_r. See the gnulib time_r module for one way
to implement this. */
-# undef __gmtime_r
-# undef __localtime_r
-# define __gmtime_r gmtime_r
-# define __localtime_r localtime_r
-
# define __mktime_internal mktime_internal
+# define __tz_convert tz_convert
#endif
/* Subroutine of mktime. Return the time_t representation of TP and
- normalize TP, given that a struct tm * maps to a time_t as performed
- by FUNC. Record next guess for localtime-gmtime offset in *OFFSET. */
-extern __time64_t __mktime_internal (struct tm *tp,
- struct tm *(*func) (__time64_t const *,
- struct tm *),
+ normalize TP, in local time if USE_LOCAL. Record next guess for
+ localtime-gmtime offset in *OFFSET. */
+extern __time64_t __mktime_internal (struct tm *tp, bool use_local,
mktime_offset_t *offset) attribute_hidden;
diff --git a/time/mktime.c b/time/mktime.c
index 86d496ca65..2a1a925b75 100644
--- a/time/mktime.c
+++ b/time/mktime.c
@@ -250,29 +250,17 @@ tm_diff (long_int year, long_int yday, int hour, int min, int sec,
tp->tm_hour, tp->tm_min, tp->tm_sec);
}
-/* Use CONVERT to convert T to a struct tm value in *TM. T must be in
- range for __time64_t. Return TM if successful, NULL (setting errno) on
- failure. */
-static struct tm *
-convert_time (struct tm *(*convert) (const __time64_t *, struct tm *),
- long_int t, struct tm *tm)
-{
- __time64_t x = t;
- return convert (&x, tm);
-}
-
-/* Use CONVERT to convert *T to a broken down time in *TP.
+/* Convert *T to a broken down time in *TP. Use local time if USE_LOCAL.
If *T is out of range for conversion, adjust it so that
it is the nearest in-range value and then convert that.
A value is in range if it fits in both __time64_t and long_int.
Return TP on success, NULL (setting errno) on failure. */
static struct tm *
-ranged_convert (struct tm *(*convert) (const __time64_t *, struct tm *),
- long_int *t, struct tm *tp)
+ranged_convert (long_int *t, bool use_local, struct tm *tp)
{
long_int t1 = (*t < mktime_min ? mktime_min
: *t <= mktime_max ? *t : mktime_max);
- struct tm *r = convert_time (convert, t1, tp);
+ struct tm *r = __tz_convert (t1, use_local, tp);
if (r)
{
*t = t1;
@@ -293,7 +281,7 @@ ranged_convert (struct tm *(*convert) (const __time64_t *, struct tm *),
long_int mid = long_int_avg (ok, bad);
if (mid == ok || mid == bad)
break;
- if (convert_time (convert, mid, tp))
+ if (__tz_convert (mid, use_local, tp))
ok = mid, oktm = *tp;
else if (errno != EOVERFLOW)
return NULL;
@@ -310,28 +298,28 @@ ranged_convert (struct tm *(*convert) (const __time64_t *, struct tm *),
/* Convert *TP to a __time64_t value, inverting
- the monotonic and mostly-unit-linear conversion function CONVERT.
+ the monotonic and mostly-unit-linear conversion function
+ gmtime_r or localtime_r (if USE_LOCAL).
Use *OFFSET to keep track of a guess at the offset of the result,
compared to what the result would be for UTC without leap seconds.
- If *OFFSET's guess is correct, only one CONVERT call is needed.
+ If *OFFSET's guess is correct, only one conversion call is needed.
If successful, set *TP to the canonicalized struct tm;
otherwise leave *TP alone, return ((time_t) -1) and set errno.
This function is external because it is used also by timegm.c. */
__time64_t
-__mktime_internal (struct tm *tp,
- struct tm *(*convert) (const __time64_t *, struct tm *),
- mktime_offset_t *offset)
+__mktime_internal (struct tm *tp, bool use_local, mktime_offset_t *offset)
{
struct tm tm;
- /* The maximum number of probes (calls to CONVERT) should be enough
- to handle any combinations of time zone rule changes, solar time,
- leap seconds, and oscillations around a spring-forward gap.
- POSIX.1 prohibits leap seconds, but some hosts have them anyway. */
+ /* The maximum number of probes (calls to gmtime_r/localime_r)
+ should be enough to handle any combinations of time zone rule
+ changes, solar time, leap seconds, and oscillations around a
+ spring-forward gap. POSIX.1 prohibits leap seconds, but some
+ hosts have them anyway. */
int remaining_probes = 6;
- /* Time requested. Copy it in case CONVERT modifies *TP; this can
- occur if TP is localtime's returned value and CONVERT is localtime. */
+ /* Time requested. Copy it in case the probe modifies *TP; this can
+ occur if TP is localtime's returned value and USE_LOCAL. */
int sec = tp->tm_sec;
int min = tp->tm_min;
int hour = tp->tm_hour;
@@ -376,8 +364,8 @@ __mktime_internal (struct tm *tp,
sec = 59;
}
- /* Invert CONVERT by probing. First assume the same offset as last
- time. */
+ /* Invert gmtime_r/localtime_r by probing. First assume the same
+ offset as last time. */
INT_SUBTRACT_WRAPV (0, off, &negative_offset_guess);
long_int t0 = ydhms_diff (year, yday, hour, min, sec,
@@ -389,7 +377,7 @@ __mktime_internal (struct tm *tp,
while (true)
{
- if (! ranged_convert (convert, &t, &tm))
+ if (! ranged_convert (&t, use_local, &tm))
return -1;
long_int dt = tm_diff (year, yday, hour, min, sec, &tm);
if (dt == 0)
@@ -468,7 +456,7 @@ __mktime_internal (struct tm *tp,
if (! INT_ADD_WRAPV (t, delta * direction, &ot))
{
struct tm otm;
- if (! ranged_convert (convert, &ot, &otm))
+ if (! ranged_convert (&ot, use_local, &otm))
return -1;
if (! isdst_differ (isdst, otm.tm_isdst))
{
@@ -478,7 +466,7 @@ __mktime_internal (struct tm *tp,
&otm);
if (mktime_min <= gt && gt <= mktime_max)
{
- if (convert_time (convert, gt, &tm))
+ if (__tz_convert (gt, use_local, &tm))
{
t = gt;
goto offset_found;
@@ -492,7 +480,8 @@ __mktime_internal (struct tm *tp,
/* No unusual DST offset was found nearby. Assume one-hour DST. */
t += 60 * 60 * dst_difference;
- if (mktime_min <= t && t <= mktime_max && convert_time (convert, t, &tm))
+ if (mktime_min <= t && t <= mktime_max
+ && __tz_convert (t, use_local, &tm))
goto offset_found;
__set_errno (EOVERFLOW);
@@ -519,7 +508,7 @@ __mktime_internal (struct tm *tp,
__set_errno (EOVERFLOW);
return -1;
}
- if (! convert_time (convert, t, &tm))
+ if (! __tz_convert (t, use_local, &tm))
return -1;
}
@@ -542,7 +531,7 @@ __mktime64 (struct tm *tp)
# if defined _LIBC || NEED_MKTIME_WORKING
static mktime_offset_t localtime_offset;
- return __mktime_internal (tp, __localtime64_r, &localtime_offset);
+ return __mktime_internal (tp, true, &localtime_offset);
# else
# undef mktime
return mktime (tp);
diff --git a/time/timegm.c b/time/timegm.c
index 5e5fa0127f..ac3f98036d 100644
--- a/time/timegm.c
+++ b/time/timegm.c
@@ -31,7 +31,7 @@ __timegm64 (struct tm *tmp)
{
static mktime_offset_t gmtime_offset;
tmp->tm_isdst = 0;
- return __mktime_internal (tmp, __gmtime64_r, &gmtime_offset);
+ return __mktime_internal (tmp, false, &gmtime_offset);
}
#if defined _LIBC && __TIMESIZE != 64
--
2.47.1
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