* private.h, zdump.c (_GNU_SOURCE): New macro. * private.h (TM_GMTOFF) [!NO_TM_GMTOFF]: (TM_ZONE) [!NO_TM_ZONE]: Guess definition if not already defined. * Makefile, NEWS: Document the above. --- Makefile | 23 +++++------------------ NEWS | 4 ++++ private.h | 16 ++++++++++++++++ zdump.c | 3 +++ 4 files changed, 28 insertions(+), 18 deletions(-) diff --git a/Makefile b/Makefile index 4703cba..fa110e2 100644 --- a/Makefile +++ b/Makefile @@ -161,25 +161,12 @@ GCC_DEBUG_FLAGS = -Dlint -g3 -O3 -fno-common -fstrict-aliasing \ # (or if you decide to add such a field in your system's "time.h" file), # add the name to a define such as # -DTM_GMTOFF=tm_gmtoff -# or -# -DTM_GMTOFF=_tm_gmtoff -# to the end of the "CFLAGS=" line. -# Neither tm_gmtoff nor _tm_gmtoff is described in X3J11's work; -# in its work, use of "tm_gmtoff" is described as non-conforming. -# Both Linux and BSD have done the equivalent of defining TM_GMTOFF in -# their recent releases. -# -# If your system has a "zone abbreviation" field in its "struct tm"s -# (or if you decide to add such a field in your system's "time.h" file), -# add the name to a define such as +# to the end of the "CFLAGS=" line. If not defined, the code attempts to +# guess TM_GMTOFF from other macros; define NO_TM_GMTOFF to suppress this. +# Similarly, if your system has a "zone abbreviation" field, define # -DTM_ZONE=tm_zone -# or -# -DTM_ZONE=_tm_zone -# to the end of the "CFLAGS=" line. -# Neither tm_zone nor _tm_zone is described in X3J11's work; -# in its work, use of "tm_zone" is described as non-conforming. -# Both UCB and Sun have done the equivalent of defining TM_ZONE in -# their recent releases. +# and define NO_TM_ZONE to suppress any guessing. These two fields are not +# required by POSIX, but are widely available on GNU/Linux and BSD dystems. # # If you want functions that were inspired by early versions of X3J11's work, # add diff --git a/NEWS b/NEWS index 335a7cf..7bc8b05 100644 --- a/NEWS +++ b/NEWS @@ -51,6 +51,10 @@ Unreleased, experimental changes 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. + 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. + tzselect -c now uses a hybrid distance measure that works better in Africa. (Thanks to Alan Barrett for noting the problem.) diff --git a/private.h b/private.h index 9482790..2389e37 100644 --- a/private.h +++ b/private.h @@ -71,6 +71,9 @@ #define ctime_r _incompatible_ctime_r #endif /* HAVE_INCOMPATIBLE_CTIME_R */ +/* Enable tm_gmtoff and tm_zone on GNUish systems. */ +#define _GNU_SOURCE 1 + /* ** Nested includes */ @@ -337,6 +340,19 @@ time_t posix2time(time_t); # endif #endif +/* Infer TM_ZONE on systems where this information is known, but suppress + guessing if NO_TM_ZONE is defined. Similarly for TM_GMTOFF. */ +#if (defined __GLIBC__ \ + || defined __FreeBSD__ || defined __NetBSD__ || defined __OpenBSD__ \ + || (defined __APPLE__ && defined __MACH__)) +# if !defined TM_GMTOFF && !defined NO_TM_GMTOFF +# define TM_GMTOFF tm_gmtoff +# endif +# if !defined TM_ZONE && !defined NO_TM_ZONE +# define TM_ZONE tm_zone +# endif +#endif + /* ** Private function declarations. */ diff --git a/zdump.c b/zdump.c index e9a42fd..070ad3c 100644 --- a/zdump.c +++ b/zdump.c @@ -18,6 +18,9 @@ # include "private.h" #endif +/* Enable tm_gmtoff and tm_zone on GNUish systems. */ +#define _GNU_SOURCE 1 + #include "stdio.h" /* for stdout, stderr, perror */ #include "string.h" /* for strcpy */ #include "sys/types.h" /* for time_t */ -- 1.9.1