[tz] [PROPOSED PATCH 2/2] Allow -Dtime_tz=... libs alongside standard libs

[Paul Eggert]

Allow libraries built with -Dtime_tz=... to be used in executables
that also use standard-library time_t and libraries.
(Problem reported by Bradley White.)
* NEWS: Document this.
* private.h (localtime_rz, mktime_rz, posix2time_z, time2posix_z)
(tzalloc, tzfree, tzset, tzsetwall) [time_tz]: Define to
tz_localtime_rz etc., so that these functions can be used in the
same executable as standard functions with standard time_t.
(tzset, tzsetwall) [time_tz]: Declare, so that the tz_-prefixed
version ins declared.
---
 NEWS      |  4 +++-
 private.h | 19 ++++++++++++++++++-
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/NEWS b/NEWS
index 89b5349..47f707b 100644
--- a/NEWS
+++ b/NEWS
@@ -34,7 +34,9 @@ Unreleased, experimental changes
     Fix integer overflow bug in reference 'mktime' implementation.
     (Problem reported by Jörg Richter.)
 
-    Allow -Dtime_tz=time_t compilations.  (Problem reported by Bradley White.)
+    Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries
+    to be used in the same executable as standard-library time_t functions.
+    (Problems reported by Bradley White.)
 
   Changes affecting commentary
 
diff --git a/private.h b/private.h
index b9429ae..de9c13e 100644
--- a/private.h
+++ b/private.h
@@ -324,16 +324,24 @@ typedef time_tz tz_time_t;
 # define localtime tz_localtime
 # undef  localtime_r
 # define localtime_r tz_localtime_r
+# undef  localtime_rz
+# define localtime_rz tz_localtime_rz
 # undef  mktime
 # define mktime tz_mktime
+# undef  mktime_z
+# define mktime_z tz_mktime_z
 # undef  offtime
 # define offtime tz_offtime
 # undef  posix2time
 # define posix2time tz_posix2time
+# undef  posix2time_z
+# define posix2time_z tz_posix2time_z
 # undef  time
 # define time tz_time
 # undef  time2posix
 # define time2posix tz_time2posix
+# undef  time2posix_z
+# define time2posix_z tz_time2posix_z
 # undef  time_t
 # define time_t tz_time_t
 # undef  timegm
@@ -342,6 +350,14 @@ typedef time_tz tz_time_t;
 # define timelocal tz_timelocal
 # undef  timeoff
 # define timeoff tz_timeoff
+# undef  tzalloc
+# define tzalloc tz_tzalloc
+# undef  tzfree
+# define tzfree tz_tzfree
+# undef  tzset
+# define tzset tz_tzset
+# undef  tzsetwall
+# define tzsetwall tz_tzsetwall
 
 char *ctime(time_t const *);
 char *ctime_r(time_t const *, char *);
@@ -352,6 +368,7 @@ struct tm *localtime(time_t const *);
 struct tm *localtime_r(time_t const *restrict, struct tm *restrict);
 time_t mktime(struct tm *);
 time_t time(time_t *);
+void tzset(void);
 #endif
 
 /*
@@ -370,7 +387,7 @@ extern char *	asctime_r(struct tm const *restrict, char *restrict);
 */
 
 #ifdef STD_INSPIRED
-# if !defined tzsetwall
+# if !defined tzsetwall || defined time_tz
 void tzsetwall(void);
 # endif
 # if !defined offtime || defined time_tz
-- 
2.1.0