By default, assume the compiler and library support C99 or later. Continue to port to C89 platforms only if the new macro PORT_TO_C89 is nonzero. This new macro is a transitional aid, and is planned to be removed in a future version that always assumes C99 or later. * Makefile, NEWS: Mention this. * private.h (PORT_TO_C89): New macro. (SUPPORT_C89): Move up. (true, false, bool) [!PORT_TO_C89]: Assume C99 or later. If !PORT_TO_C89 simply include <inttypes.h> rather than fooling around with conditional stdint.h, conditional inttypes.h, and lots of other conditional definitions. (restrict) [!PORT_TO_C89]: Do not define. * zdump.c (HAVE_SNPRINTF) [!PORT_TO_C89]: Now true. --- Makefile | 14 ++++++++------ NEWS | 11 ++++++----- private.h | 35 +++++++++++++++++++++++++---------- zdump.c | 2 +- 4 files changed, 40 insertions(+), 22 deletions(-) diff --git a/Makefile b/Makefile index 63f3b5ca..8bee50d8 100644 --- a/Makefile +++ b/Makefile @@ -220,7 +220,7 @@ LDLIBS= # -DHAVE_INCOMPATIBLE_CTIME_R if your system's time.h declares # ctime_r and asctime_r incompatibly with the POSIX standard # (Solaris when _POSIX_PTHREAD_SEMANTICS is not defined). -# -DHAVE_INTTYPES_H=0 if <inttypes.h> does not work* +# -DHAVE_INTTYPES_H=0 if <inttypes.h> does not work*+ # -DHAVE_LINK=0 if your system lacks a link function # -DHAVE_LOCALTIME_R=0 if your system lacks a localtime_r function # -DHAVE_LOCALTIME_RZ=0 if you do not want zdump to use localtime_rz @@ -229,24 +229,24 @@ LDLIBS= # -DHAVE_POSIX_DECLS=0 if your system's include files do not declare # functions like 'link' or variables like 'tzname' required by POSIX # -DHAVE_SETENV=0 if your system lacks the setenv function -# -DHAVE_SNPRINTF=0 if your system lacks the snprintf function +# -DHAVE_SNPRINTF=0 if your system lacks the snprintf function+ # -DHAVE_STDCKDINT_H=0 if neither <stdckdint.h> nor substitutes like # __builtin_add_overflow work* -# -DHAVE_STDINT_H=0 if <stdint.h> does not work* +# -DHAVE_STDINT_H=0 if <stdint.h> does not work*+ # -DHAVE_STRFTIME_L if <time.h> declares locale_t and strftime_l # -DHAVE_STRDUP=0 if your system lacks the strdup function -# -DHAVE_STRTOLL=0 if your system lacks the strtoll function +# -DHAVE_STRTOLL=0 if your system lacks the strtoll function+ # -DHAVE_SYMLINK=0 if your system lacks the symlink function # -DHAVE_SYS_STAT_H=0 if <sys/stat.h> does not work* # -DHAVE_TZSET=0 if your system lacks a tzset function # -DHAVE_UNISTD_H=0 if <unistd.h> does not work* # -DHAVE_UTMPX_H=0 if <utmpx.h> does not work* # -Dlocale_t=XXX if your system uses XXX instead of locale_t +# -DPORT_TO_C89 if tzcode should also run on C89 platforms+ # -DRESERVE_STD_EXT_IDS if your platform reserves standard identifiers # with external linkage, e.g., applications cannot define 'localtime'. # -Dssize_t=long on hosts like MS-Windows that lack ssize_t -# -DSUPPORT_C89 if you build or run tzcode on a C89 platform; this option -# is obsolescent and is planned to be removed when C99+ is required. +# -DSUPPORT_C89 if the tzcode library should support C89 callers+ # -DSUPPRESS_TZDIR to not prepend TZDIR to file names; this has # security implications and is not recommended for general use # -DTHREAD_SAFE to make localtime.c thread-safe, as POSIX requires; @@ -275,6 +275,8 @@ LDLIBS= # $(GCC_DEBUG_FLAGS) if you are using recent GCC and want lots of checking # # * Options marked "*" can be omitted if your compiler is C23 compatible. +# * Options marked "+" are obsolescent and are planned to be removed +# once the code assumes C99 or later. # # Select instrumentation via "make GCC_INSTRUMENT='whatever'". GCC_INSTRUMENT = \ diff --git a/NEWS b/NEWS index 25dcc875..91ec5056 100644 --- a/NEWS +++ b/NEWS @@ -3,15 +3,16 @@ News for the tz database Unreleased, experimental changes Briefly: - tzcode no longer supports C89 unless built with -DSUPPORT_C89 + The code now defaults to C99 or later. Fix use of C23 attributes. Changes to code - tzcode no longer supports C89 by default. To build or run in a - C89 environment, compile with -DSUPPORT_C89, a transitional aid - that is planned to be removed in a near-future version, when C99 - or later will be required. + The code by default is now designed for C99 or later. To build in + a C89 environment, compile with -DPORT_TO_C89. To support C89 + callers of the tzcode library, compile with -DSUPPORT_C89. The + two new macros are transitional aids planned to be removed in a + future version, when C99 or later will be required. On C23-compatible platforms tzcode no longer uses syntax like 'static [[noreturn]] void usage(void);'. Instead, it uses diff --git a/private.h b/private.h index 999c1648..1d6ddf73 100644 --- a/private.h +++ b/private.h @@ -17,12 +17,25 @@ ** Thank you! */ +/* PORT_TO_C89 means the code should work even if the underlying + compiler and library support only C89. SUPPORT_C89 means the + tzcode library should support C89 callers in addition to the usual + support for C99-and-later callers. These macros are obsolescent, + and the plan is to remove them along with any code needed only when + they are nonzero. */ +#ifndef PORT_TO_C89 +# define PORT_TO_C89 0 +#endif +#ifndef SUPPORT_C89 +# define SUPPORT_C89 0 +#endif + #ifndef __STDC_VERSION__ # define __STDC_VERSION__ 0 #endif /* Define true, false and bool if they don't work out of the box. */ -#if __STDC_VERSION__ < 199901 +#if PORT_TO_C89 && __STDC_VERSION__ < 199901 # define true 1 # define false 0 # define bool int @@ -100,10 +113,6 @@ # define HAVE_STRDUP 1 #endif -#ifndef HAVE_STRTOLL -# define HAVE_STRTOLL 1 -#endif - #ifndef HAVE_SYMLINK # define HAVE_SYMLINK 1 #endif /* !defined HAVE_SYMLINK */ @@ -185,6 +194,9 @@ #include <stddef.h> #include <string.h> +#if !PORT_TO_C89 +# include <inttypes.h> +#endif #include <limits.h> /* for CHAR_BIT et al. */ #include <stdlib.h> @@ -254,6 +266,8 @@ # define R_OK 4 #endif /* !defined R_OK */ +#if PORT_TO_C89 + /* ** Define HAVE_STDINT_H's default value here, rather than at the ** start, since __GLIBC__ and INTMAX_MAX's values depend on @@ -334,6 +348,9 @@ typedef int int_fast32_t; #ifndef INTMAX_MAX # ifdef LLONG_MAX typedef long long intmax_t; +# ifndef HAVE_STRTOLL +# define HAVE_STRTOLL true +# endif # if HAVE_STRTOLL # define strtoimax strtoll # endif @@ -396,6 +413,8 @@ typedef unsigned long uintmax_t; # define SIZE_MAX ((size_t) -1) #endif +#endif /* PORT_TO_C89 */ + /* Support ckd_add, ckd_sub, ckd_mul on C23 or recent-enough GCC-like hosts, unless compiled with -DHAVE_STDCKDINT_H=0 or with pre-C23 EDG. */ #if !defined HAVE_STDCKDINT_H && defined __has_include @@ -520,7 +539,7 @@ typedef unsigned long uintmax_t; # endif #endif -#if __STDC_VERSION__ < 199901 && !defined restrict +#if PORT_TO_C89 && __STDC_VERSION__ < 199901 && !defined restrict # define restrict /* empty */ #endif @@ -704,10 +723,6 @@ extern int daylight; extern long altzone; #endif -#ifndef SUPPORT_C89 -# define SUPPORT_C89 0 -#endif - /* ** The STD_INSPIRED functions are similar, but most also need ** declarations if time_tz is defined. diff --git a/zdump.c b/zdump.c index bac4a67a..5173c9ac 100644 --- a/zdump.c +++ b/zdump.c @@ -15,7 +15,7 @@ #include <stdio.h> #ifndef HAVE_SNPRINTF -# define HAVE_SNPRINTF (199901 <= __STDC_VERSION__) +# define HAVE_SNPRINTF (!PORT_TO_C89 || 199901 <= __STDC_VERSION__) #endif #ifndef HAVE_LOCALTIME_R -- 2.37.2