[tz] [PROPOSED PATCH 3/3] * NEWS: Reorganize recent code news clarity, and mention tzdist.

Paul Eggert eggert at cs.ucla.edu
Wed Aug 27 01:51:47 UTC 2014


---
 NEWS | 63 ++++++++++++++++++++++++++++++++-------------------------------
 1 file changed, 32 insertions(+), 31 deletions(-)

diff --git a/NEWS b/NEWS
index fcb79a3..ab97918 100644
--- a/NEWS
+++ b/NEWS
@@ -42,34 +42,49 @@ Unreleased, experimental changes
 
   Changes affecting code
 
-    Some crashes have been fixed when zdump or the tz library is given
-    invalid or outlandish input.
+    Unless NETBSD_INSPIRED is defined to 0, the tz library now
+    supplies functions for creating and using objects that represent
+    time zones. The new functions are tzalloc, tzfree, localtime_rz,
+    mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and
+    time2posix_z.  They are intended for performance: for example,
+    localtime_rz (unlike localtime_r) is trivially thread-safe without
+    locking.  (Thanks to Christos Zoulas for proposing NetBSD-inspired
+    functions, and to Alan Barrett and Jonathan Lennox for helping to
+    debug the change.)
 
-    The tz library no longer mishandles leap seconds on platforms with
-    unsigned time_t in time zones that lack ordinary transitions after 1970.
+    zdump now builds with the tz library unless USE_LTZ is defined to 0,
+    This lets zdump use tz features even if the system library lacks them.
+    To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0
+    TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='.
+
+    zdump now uses localtime_rz if available, as it's significantly faster,
+    and it can help zdump better diagnose invalid time zone names.
+    Define HAVE_LOCALTIME_RZ to 0 to suppress this.  HAVE_LOCALTIME_TZ
+    defaults to 1 if NETBSD_INSPIRED && USE_LTZ.  When localtime_rz is
+    not available, zdump now uses localtime_r and tzset if available,
+    as this is a bit cleaner and faster than plain localtime.  Compile
+    with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system
+    lacks these two functions.
 
-    The tz library is now thread-safe if compiled with THREAD_SAFE defined.
+    If THREAD_SAFE is defined to 1, the tz library is now thread-safe.
     Although not needed for tz's own applications, which are single-threaded,
     this supports POSIX better if the tz library is used in multithreaded apps.
 
-    Unless NETBSD_INSPIRED is defined to 0, the tz library now supplies
-    functions that let callers create and use objects representing time zones.
-    This is intended for applications that need to deal with many time
-    zones simultaneously, e.g., an application where each thread may be
-    in a different time zone.  The new functions are tzalloc, tzfree,
-    localtime_rz, mktime_z, and (if STD_INSPIRED is also defined)
-    posix2time_z and time2posix_z.  (Thanks to Alan Barrett and
-    Jonathan Lennox for helping to debug this.)
+    Some crashes have been fixed when zdump or the tz library is given
+    invalid or outlandish input.
+
+    The tz library no longer mishandles leap seconds on platforms with
+    unsigned time_t in time zones that lack ordinary transitions after 1970.
 
     The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not
     already defined, to make it easier to configure on common platforms.
     Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this.
 
-    Unless the new macro UNINIT_TRAP is defined to 0, the tz code now
+    Unless the new macro UNINIT_TRAP is defined to 1, the tz code now
     assumes that reading uninitialized memory yields garbage values
     but does not cause other problems such as traps.
 
-    If TM_GMTOFF is defined and UNINIT_TRAP is not 0, mktime is now
+    If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
     more likely to guess right for ambiguous time stamps near
     transitions where tm_isdst does not change.
 
@@ -78,20 +93,6 @@ Unreleased, experimental changes
     Only the C locale is supported, though.  HAVE_STRFTIME_L defaults
     to 1 on recent POSIX versions, and to 0 otherwise.
 
-    zdump now builds with the tz library unless USE_LTZ is defined to 0,
-    This lets zdump use tz features even if the system library lacks them.
-    To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0
-    TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='.
-
-    zdump now uses localtime_rz if available, as it's significantly faster,
-    and it can help zdump better diagnose invalid time zone names.
-    Define HAVE_LOCALTIME_RZ to 0 to suppress this.  HAVE_LOCALTIME_TZ
-    defaults to 1 if NETBSD_INSPIRED && USE_LTZ.  When localtime_rz is
-    not available, zdump now uses localtime_r and tzset if available,
-    as this is a bit cleaner and faster than plain localtime.  Compile
-    with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system
-    lacks these two functions.
-
     tzselect -c now uses a hybrid distance measure that works better
     in Africa.  (Thanks to Alan Barrett for noting the problem.)
 
@@ -145,8 +146,8 @@ Unreleased, experimental changes
     and more like the parameters of 'ln'.  LINK-FROM has become TARGET,
     and LINK-TO has become LINK-NAME.
 
-    tz-link.htm mentions Windows Runtime etc. (thanks to Matt Johnson)
-    and HP-UX's tztab.
+    tz-link.htm mentions the IETF's tzdist working group; Windows
+    Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab.
 
     Some broken URLs have been fixed in the commentary.  (Thanks to
     Lester Caine.)
-- 
1.9.1



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