[PATCH v2 2/2] Simplify tzdb-related configuration

[Adhemerval Zanella Netto]

On 13/05/26 15:08, Paul Eggert wrote:
> tzdb 2026b no longer needs -Wno-discarded-qualifiers or
> -Wno-unused-variable.  From a suggestion by Joseph Myers in:
> https://sourceware.org/pipermail/libc-alpha/2026-May/177312.html
> * configure.ac (config-cflags-wno-discarded-qualifiers): Remove.
> * timezone/Makefile (CFLAGS-zic.c): Remove -Wno-unused-variable,
> $(config-cflags-wno-discarded-qualifiers).


LGTM, thanks.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>


> ---
>  configure.ac      | 16 ----------------
>  timezone/Makefile |  7 +------
>  2 files changed, 1 insertion(+), 22 deletions(-)
> 
> diff --git a/configure.ac b/configure.ac
> index 280ec8e5b3..e9138a38b7 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -1371,22 +1371,6 @@ LIBC_TRY_CC_OPTION([-fpie], [libc_cv_fpie=yes], [libc_cv_fpie=no])
>  
>  AC_SUBST(libc_cv_fpie)
>  
> -dnl Check how to suppress C23-qualifier-generic const warnings.  GCC has
> -dnl -Wno-discarded-qualifiers, while clang -Wno-incompatible-pointer-types-discards-qualifiers
> -AC_CACHE_CHECK(for -Wno-discarded-qualifiers, libc_cv_cflags_wno_discarded_qualifiers, [dnl
> -LIBC_TRY_CC_OPTION([-Werror -Wno-discarded-qualifiers],
> -		   [libc_cv_cflags_wno_discarded_qualifiers=-Wno-discarded-qualifiers],
> -		   [libc_cv_cflags_wno_discarded_qualifiers=])
> -if test -z "$libc_cv_cflags_wno_discarded_qualifiers"; then
> -  LIBC_TRY_CC_OPTION([-Werror -Wno-incompatible-pointer-types-discards-qualifiers],
> -		     [libc_cv_cflags_wno_incompatible_pointer_type_discards_qualifiers=-Wno-incompatible-pointer-types-discards-qualifiers],
> -		     [libc_cv_cflags_wno_incompatible_pointer_type_discards_qualifiers=])
> -  libc_cv_cflags_wno_discarded_qualifiers=$libc_cv_cflags_wno_incompatible_pointer_type_discards_qualifiers
> -fi
> -])
> -LIBC_CONFIG_VAR([config-cflags-wno-discarded-qualifiers],
> -		[$libc_cv_cflags_wno_discarded_qualifiers])
> -
>  AC_CACHE_CHECK(for GLOB_DAT reloc,
>  	       libc_cv_has_glob_dat, [dnl
>  cat > conftest.c <<EOF
> diff --git a/timezone/Makefile b/timezone/Makefile
> index 386731ab99..426061737a 100644
> --- a/timezone/Makefile
> +++ b/timezone/Makefile
> @@ -70,13 +70,8 @@ tz-cflags = -DTZDIR='"$(zonedir)"' \
>  	    -DHAVE_GETTEXT -DUSE_LTZ=0 -D_ISOMAC -DTZ_DOMAIN='"libc"' \
>  	    -include $(common-objpfx)config.h $(config-cflags-wno-maybe-uninitialized)
>  
> -# The -Wno-unused-variable flag is used to prevent GCC 6
> -# from warning about time_t_min and time_t_max which are
> -# defined in private.h but not used.
> -# $(config-cflags-wno-discarded-qualifiers) is because zic is not prepared for C23
> -# -qualifier-generic strchr.
>  CFLAGS-zdump.c += $(tz-cflags)
> -CFLAGS-zic.c += $(tz-cflags) -Wno-unused-variable $(config-cflags-wno-discarded-qualifiers)
> +CFLAGS-zic.c += $(tz-cflags)
>  
>  # We have to make sure the data for testing the tz functions is available.
>  # Don't add leapseconds here since test-tz made checks that work only without