term-style-control: Make multithread-safe, part 2: Improve logging.

* lib/term-style-control.c: Include <stdint.h>, <pthread.h>.
(HAVE_POSIX_THREADS): New macro.
(log_message): Preserve errno.
(sprintf_integer_hex): New function.
(log_signal_handler_called): Show also the current thread ID.
(fatal_or_stopping_signal_handler): Add log_message invocations to show
the taken code path.
* modules/term-style-control (Depends-on): Add stdint-h.
(configure.ac): Test for <pthread.h>.

term-style-control: Make multithread-safe, part 1.

* lib/term-style-control.h (activate_term_style_controller): Document a
constraint regarding thread creation.
(activate_term_non_default_mode): Document threading constraint.

term-style-control tests: Add a test with multithreading.

* tests/test-term-style-control-yes.h: New file, based on
tests/test-term-style-control-yes.c.
* tests/test-term-style-control-yes.c: Move most definitions to
tests/test-term-style-control-yes.h.
Include test-term-style-control-yes.h.
(main): Just invoke styled_yes_loop.
* tests/test-term-style-control-yes-mt.c: New file.
* modules/term-style-control-tests (Files): Add
tests/test-term-style-control-yes.h,
tests/test-term-style-control-yes-mt.c.
(Depends-on): Add thread, nanosleep.
(Makefile.am): Arrange to build test-term-style-control-yes-mt.

thread-optim: Update documentation.

* doc/multithread.texi (Multithreading Optimizations): Update the
platforms list.

fatal-signal: Make really multithread-safe.

* lib/fatal-signal.h (block_fatal_signals): Document a constraint
regarding thread creation.
* lib/fatal-signal.c: Include sigdelay.h.
(fatal_signals_block_initially_mt): New variable.
(block_fatal_signals, unblock_fatal_signals): In a multithreaded
process, use sigdelay instead of pthread_sigmask.
* modules/fatal-signal (Depends-on): Add sigdelay.

thread-optim: Add tests.

* tests/test-thread-optim1.c: New file.
* tests/test-thread-optim2.c: New file.
* modules/thread-optim-tests: New file.

thread-optim: Port to older glibc, musl libc, *BSD, Solaris, Android.

* lib/thread-optim.h: Include <stdbool.h>.
(gl_multithreaded): Define differently on ELF platforms.
(_GL_MULTITHREADED_ALWAYS_TRUE, _GL_MULTITHREADED_VIA_ELF): New macros.
(gl_set_multithreaded): New declaration.
* lib/thread-optim.c: New file.
* lib/thread-creators.gperf: New file.
* lib/thread-optim-proto.c: New file.
* modules/thread-optim (Files): Add these files.
(Depends-on): Add gperf, bool, stdint-h.
(configure.ac): Test for <link.h>, dl_iterate_phdr.
(Makefile.am): Compile thread-optim.c. Create thread-creators.h through
gperf.

tweak

intprops-tests: check TYPE_SIGNED (char)

* tests/test-intprops.c (main): Also check TYPE_SIGNED on ‘char’.

intprops-tests: new boundary tests

* tests/test-intprops.c (CHECK_BOUNDARIES): New macro,
implementing more tests.

intprops: Fix compilation error in MSVC.

* lib/intprops.h (TYPE_IS_INTEGER, TYPE_MINIMUM, TYPE_MAXIMUM): Don't
use _Generic to distinguish between 'char' and 'signed char' with MSVC
before version 14.44.
* lib/intprops-internal.h (_GL_TYPE_SIGNED): Likewise.

regex: Fix "macro redefinition" warning on MSVC.

* lib/regex_internal.h (wctype_t): Undefine before redefining it.

announce-gen: Ignore libtoolize --version Debianism

* build-aux/announce-gen (get_tool_versions): Ignore trailing ' Debian*'.

maintainer-makefile: Fix sc_po_check failure.

* top/maint.mk (perl_translatable_files_list_): Filter out gettext.h.

localeinfo: Make sure mbszero can be called.

* lib/localeinfo.c: Include <wchar.h>.
* modules/localeinfo (Depends-on): Add wchar-h.

error: Restore library name-spacing of verror_at_line.

* lib/error.in.h (verror_at_line): Don't define as a macro if
_GL_NO_INLINE_ERROR is defined.

stdc_bit_floor, stdc_bit_ceil: Work around Solaris 11 OpenIndiana bug.

* lib/stdbit.in.h (stdc_bit_floor, stdc_bit_ceil): Override the macro
definition from Solaris 11.
* doc/posix-functions/stdc_bit_floor.texi: Mention the Solaris 11
OpenIndiana bug.
* doc/posix-functions/stdc_bit_ceil.texi: Likewise.

unictype/base: Fix compilation error on systems with libunistring 1.3.

* modules/unictype/base (configure.ac): Omit generating unictype.h in
the presence of libunistring >= 1.4, not >= 1.3.

gettext-h: Tweak comments.

* lib/gettext.h: Small comment improvements.

stat-time: Use countof.

* lib/stat-time.h: Include <stdcountof.h>.
(stat_time_normalize): Use countof.
* modules/stat-time (Depends-on): Add stdcountof-h.
* modules/relocatable-prog-wrapper (Depends-on): Likewise.

setlocale: Use countof.

* lib/setlocale.c: Include <stdcountof.h>.
(setlocale_unixlike, get_main_locale_with_same_language,
get_main_locale_with_same_territory, setlocale_improved): Use countof.
* modules/setlocale (Depends-on): Add stdcountof-h.

gettext: tweak lib/gettext.h indenting

* lib/gettext.h: fix preprocessor indenting glitches found by cppi.

gettext-h: Ensure no warnings with --disable-nls and -Wformat=2.

* lib/gettext.h (gettext, dgettext, dcgettext): Define differently for
clang.
(ngettext, dngettext, dcngettext): Define differently for gcc and clang.
With gcc in C mode, silence -Wuseless-cast warnings.

careadlinkat: pacify GCC 12+ -Wreturn-local-addr more simply

* lib/careadlinkat.c (readlink_stk):
Now also noinline when _GL_GNUC_PREREQ (12, 1) && !USING_LTO.
The small inlining performance improvement for GCC 12+ was not worth
the hassle of documenting or autoconfiguring USING_LTO.
This change removes the need for USING_LTO.
Problem reported by Bruno Haible in:
https://lists.gnu.org/r/bug-gnulib/2026-05/msg00103.html

careadlinkat: fix comment

* lib/careadlinkat.c: Fix comment.  Problem reported by Bruno Haible in:
https://lists.gnu.org/r/bug-gnulib/2026-05/msg00103.html

intprops: ignore -Wuseless-cast less often

Using _Generic instead of casting should help includers of
<intprops.h> to avoid suppression of -Wuseless-cast diagnostics.
* lib/intprops-internal.h: Ignore -Wuseless-cast only
if (__STDC_VERSION__ < 201112 && 14 <= __GNUC__).
(_GL__GENERIC_BOGUS): Move definition up.
* lib/intprops-internal.h (_GL_TYPE_SIGNED):
* lib/intprops.h (TYPE_IS_INTEGER, TYPE_MINIMUM, TYPE_MAXIMUM):
Use _Generic if this should work, to avoid the need for casts.
* lib/intprops-internal.h (_GL_INT_NEGATE_OVERFLOW):
* lib/intprops.h (_GL_ADD_OVERFLOW, _GL_SUBTRACT_OVERFLOW)
(_GL_MULTIPLY_OVERFLOW): When _GL_HAS_BUILTIN_OVERFLOW_P, use
_GL_INT_CONVERT to avoid the need for a cast.

posixtm-tests: pacify -Wuseless-cast

* tests/test-posixtm.c (main): Use compound literals, not casts.

inttostr-tests: pacify -Wuseless-cast

* tests/test-inttostr.c (CK): Use compound literals, not casts.

unilbrk/ulc-width-linebreaks: omit no-op casts

* lib/unilbrk/ulc-width-linebreaks.c (ulc_width_linebreaks_internal):
Omit casts from char * to char *.

unictype/block-test: pacify -Wuseless-cast

* lib/unictype/block_test.c (uc_is_block):
Use compound literal, not cast.

regex: omit useless casts

* lib/regex_internal.c (build_wcs_upper_buffer):
Omit cast from char * to char *.
* lib/regex_internal.h (re_string_wchar_at):
Omit casts to wint_t in a context that will already convert to wint_t.

manywarnings: fix -Wuseless-cast cataloging

* build-aux/gcc-warning.spec: Mention -Wuseless-cast as a special case.

manywarnings: add -Wstringop-overflow=4

* m4/manywarnings.m4 (gl_MANYWARN_ALL_GCC(C)): Add
-Wstringop-overflow=4.  This option, when used with GCC 16, works
with current Gnulib and with coreutils, so it seems like a good
thing to add to the default list.

careadlinkat: pacify GCC 16 -flto

Use a simpler scheme to pacify GCC.
* lib/careadlinkat.c (readlink_stk): With GCC 12+,
do not ignore -Wreturn-local-addr if -flto is being used,
as this does not work with current coreutils and with
gcc 16.1.1 20260501 (Red Hat 16.1.1-1) x86-64.
Instead, fall back on __attribute__ ((__noinline__)).
(GCC_BOGUS_WRETURN_LOCAL_ADDR): Remove.  Do not bother
with this as it complicates maintenance and is present only
for better diagnostics in older compilers.
Just use __attribute__ ((__noinline__)) instead.
All uses removed.

chown: use AC_CHECK_HEADERS_ONCE on standard headers

* m4/chown.m4 (AC_FUNC_CHOWN):
* m4/size_max.m4 (gl_SIZE_MAX):
* m4/xsize.m4 (gl_XSIZE): Prefer AC_CHECK_HEADERS_ONCE to
AC_CHECK_HEADERS for standard headers that Autoconf will use
AC_CHECK_HEADERS_ONCE on anyway.

canonicalize: use stdckdint.h not intprops.h

canonicalize: use stdckdint.h not intprops.h
<stdckdint.h> is standard, so prefer that to the pre-standard
intprops.h.
* lib/canonicalize.c: Include stdckdint.h, not intprops.h.
(canonicalize_filename_mode_stk): Use ckd_add, not INT_ADD_OVERFLOW.
* modules/canonicalize (Depends-on): Remove intprops.
Add stdckdint-h. Sort.

canonicalize: pacify -Wmaybe-uninitialized without ignoring

* lib/canonicalize.c: Do not ignore -Wmaybe-uninitialized.
(IF_LINT): Remove; no longer used.
(canonicalize_filename_mode_stk): Use a single local rather than two.
Ordinarily portmanteau variables are iffy, but this one is a win.

string-buffer-reversed: Fix comments.

* lib/string-buffer-reversed.h: Fix comments and indentation.

Revisit some -Wuseless-cast changes.

* lib/fstrcmp.c (fstrcmp_free_resources, fstrcmp_bounded): Use a
compound literal to convert to uintptr_t.
* lib/wait-process.c (wait_subprocess): Use a compound literal to
convert to int.
* lib/sigsegv.c: Revert last change. Instead, disable -Wuseless-cast
in this compilation unit.
* tests/jit/test-cache.c: Likewise.
* tests/test-limits-h.c: Disable -Wuseless-cast warnings also for
gcc 14, 15.

Fix many test failures on Windows and 32-bit AIX (regr. 2026-05-08).

* tests/test-iswdigit.c (for_character): Restore cast of constants to
wchar_t, but in the form of a compound initializer.
* tests/test-iswpunct.c (for_character): Likewise.
* tests/test-iswxdigit.c (for_character): Likewise.
* tests/test-mbrtowc.c (main): Likewise.
* tests/test-mbrtowc-w32.c (test_one_locale): Likewise.
* tests/test-mbrtowc-w32utf8.c (main): Likewise.
* tests/test-mbsnrtowcs.c (main): Likewise.
* tests/test-mbsrtowcs.c (main): Likewise.
* tests/test-mbstowcs.c (main): Likewise.
* tests/test-snprintf-posix.h (test_function): Likewise.
* tests/test-sprintf-posix.h (test_function): Likewise.
* tests/test-towctrans.c (main): Likewise.
* tests/test-vasnprintf-posix.c (test_function): Likewise.
* tests/test-vasnwprintf-posix.c (test_function): Likewise.
* tests/test-vasprintf-posix.c (test_function): Likewise.
* tests/test-wcrtomb.c (check_character): Likewise.
* tests/test-wcscmp.c (main): Likewise.
* tests/test-wcsncmp.c (main): Likewise.
* tests/test-wmemcmp.c (main): Likewise.
* m4/c32rtomb.m4 (gl_C32RTOMB_SANITYCHECK): Likewise.
* m4/iswdigit.m4 (gl_FUNC_ISWDIGIT): Likewise.
* m4/iswxdigit.m4 (gl_FUNC_ISWXDIGIT): Likewise.
* m4/mbrtoc32.m4 (gl_MBRTOC32_SANITYCHECK): Likewise.
* m4/mbrtowc.m4 (gl_MBRTOWC_NULL_ARG1, gl_MBRTOWC_STORES_INCOMPLETE):
Likewise.
* m4/mbsnrtowcs.m4 (gl_MBSNRTOWCS_WORKS_IN_TRADITIONAL_LOCALE):
Likewise.
* m4/wcrtomb.m4 (gl_FUNC_WCRTOMB): Likewise.

strings-h: Revert last change, now unnecessary.

* lib/strings.in.h: Revert last change.
* lib/string.in.h: Update comments.

signal.h: Fix compilation error on Solaris 10 in C++ mode.

* lib/signal.in.h: On Solaris in C++ mode, don't include <pthread.h>.
The include <pthread.h> is only needed for Solaris versions < 9.

sys_wait-h: Fix compilation error on Solaris 10 in C++ mode.

* lib/sys_wait.in.h (_GL_INCLUDING_SYS_WAIT_H): New macro, to avoid
recursive include problems.
* modules/sys_wait-h (Makefile.am): Substitute
INCLUDE_NEXT_AS_FIRST_DIRECTIVE, NEXT_AS_FIRST_DIRECTIVE_SYS_WAIT_H.

strnul: Fix compilation in C++ mode on Solaris 10 with Oracle Studio 12.

Reported by Paul Eggert in
<https://lists.gnu.org/archive/html/bug-gnulib/2026-05/msg00068.html>.

* lib/string.in.h (strnul): Wrap template declarations and definitions
in 'extern "C++" { ... }'.

xstring-desc: Fix link error with non-optimizing compilers.

* lib/xstring-desc.h (xsd_c): Define with GL_XSTRING_DESC_INLINE.

spawn-pipe tests: Fix link error with non-optimizing compilers.

* tests/test-spawn-pipe-child.c (print_stack_trace): Define to empty.

calloc-gnu tests: Skip expensive part on Solaris.

* tests/test-calloc-gnu.c (main): Don't attempt to allocate a huge block
of memory on Solaris.
* tests/test-malloc-gnu.c (main): Add a comment.

stdlib-h-c++-tests: Fix link error on Solaris 10 with Oracle Studio 12.

* modules/stdlib-h-c++-tests (Makefile.am): Link test-stdlib-h-c++ with
$(LIBUNISTRING).

netdb-h-c++-tests: Fix link error on Solaris 10 with Oracle Studio 12.6.

* modules/netdb-h-c++-tests (Makefile.am): Link test-netdb-h-c++ with
$(LIBINTL).

strings-h: Fix compilation error on AIX in C++ mode.

* lib/strings.in.h: On AIX in C++ mode, before including the system's
<strings.h> file, include <string.h>.

Fix 'restrict' on MSVC and on Solaris 11.4 g++ (regression 2026-05-04).

* m4/gnulib-common.m4 (AC_C_RESTRICT): Ignore the value of
__STDC_VERSION__ on MSVC or in C++ mode.

Document Solaris 10 mmap etc. issues with caddr_t

Document another quality assurance recipe.

* HACKING (Maintaining high quality): Document how to use gnulib-tool
--create-testdir with --extract-recursive-dependents.

gettext-h: fix recently-introduced category typos

* lib/gettext.h (dcgettext, dcngettext): The category arg has type
int, not const char *. Problem found on Solaris 10 with Oracle
Solaris Studio 12.6.

u64: go back to casts for u64init

* lib/u64.h (u64init) [INT_MAX < UINT64_MAX]: Don’t use a compound
literal here, as u64init is intended for use in static
initializers.  Problem reported by Bruno Haible in:
https://lists.gnu.org/r/bug-gnulib/2026-05/msg00063.html

regex-tests: pacify -Wshadow

* tests/test-regex-en.c (main): Remove unused local.
Nest one of the tests, to avoid shadowing the local ‘pat’.

Gnulib is now safe for -Wuseless-cast

* m4/gnulib-common.m4 (gl_CC_GNULIB_WARNINGS):
Remove -Wno-useless-cast.

Avoid string literal type confusion

Instead of ‘... (char *) "abc" ...’, which is a bit confusing as
"abc" is already of type char *, use ‘static char const s[] =
"abc"; ... (char *) s ....  This pacifices -Wuseless-cast.
* lib/boot-time.c (get_boot_time_uncached):
* lib/time_rz.c (save_abbr):
* tests/test-posix_spawn-chdir.c (test):
* tests/test-posix_spawn-fchdir.c (test):
* tests/test-unsetenv.c (main):
Redo with named string as described above.

times-tests: pacify -Wuseless-cast

* tests/test-times.c (tms2ms): New function.
(main): Use it to simplify printing and avoid need for casts.
Pacify -Wuseless-cast via compound literals.

strncat-tests: omit confusing casts

* tests/test-strncpy.c (check): Omit no-op cast.
* tests/unistr/test-strncat.h (check): Use better type for
page_boundary, removing the need for a cast.

limits-h-tests: suppress -Wuseless-cast

* tests/test-limits-h.c: Also borrow the suppression of
-Wuseless-cast from intprops.h.

In tests, prefer %zu to %lu+cast

* tests/test-dirname.c (main):
* tests/test-gc-pbkdf2-sha1.c (main):
* tests/test-gc-pbkdf2.c (main):
* tests/test-nonblocking-reader.h (full_read)
* tests/test-nonblocking-writer.h (main_writer_loop):
(full_read_from_nonblocking_fd):
* tests/test-read-file.c (test_read_file):
Prefer %zu to %lu plus a cast to unsigned long.
* tests/test-nonblocking-reader.h (full_read)
* tests/test-nonblocking-writer.h (main_writer_loop):
(full_read_from_nonblocking_fd):
Pacify -Wuseless-cast via compound literals.

Avoid useless casts in m4/*.m4.

This is mostly for consistency. In theory it could help
if someone mistakenly configures with -Wuseless-cast in CFLAGS.
* m4/c32rtomb.m4 (gl_C32RTOMB_SANITYCHECK):
* m4/iswdigit.m4 (gl_FUNC_ISWDIGIT):
* m4/iswxdigit.m4 (gl_FUNC_ISWXDIGIT):
* m4/mbrtoc32.m4 (gl_MBRTOC32_SANITYCHECK):
* m4/mbrtowc.m4 (gl_MBRTOWC_NULL_ARG1)
(gl_MBRTOWC_STORES_INCOMPLETE):
* m4/mbsnrtowcs.m4 (gl_MBSNRTOWCS_WORKS_IN_TRADITIONAL_LOCALE):
* m4/wcrtomb.m4 (gl_FUNC_WCRTOMB):
Do not cast to wchar_t when the context is already wchar_t.

Suppress -Wuseless-cast when calling mmap

I assume the void * casts for mmap are for ancient systems
where mmap returned char *, though Gnulib no longer ports to those.
For now, simply suppress the warning in the few places that use
mmap directly.
* lib/stackvma.c, lib/vma-iter.c, tests/mmap-anon-util.h:
Ignore -Wuseless-cast.

sigsegv: pacify -Wuseless-cast

This also makes the code a bit less confusing.
* lib/sigsegv.c (SIGSEGV_FAULT_ADDRESS): Now of type void *.
Change the Hurd implementation to guarantee this.
(sigsegv_handler): Omit no-longer needed cast to void *.
Omit function pointer cast when SIGSEGV_FAULT_ADDRESS_FROM_SIGINFO,
as it’s not needed in that case.

jit/cache-tests: omit confusing cast.

* tests/jit/test-cache.c (SET_CODE): Omit cast of char * to char *.

wait-process: omit confusing cast

* lib/wait-process.c (wait_subprocess): Omit confusing cast.

md2: omit confusing casts

* lib/md2.c (md2_process_bytes):
Use size_t, not unsigned long, for size.
Although the code was correct it was unclear.
(md2_update_chksum, md2_compress): Omit confusing casts.

Pacify -Wuseless-cast for pthread_self

* lib/glthread/thread.h (gl_thread_self_pointer):
* tests/test-pthread-mutex.c, tests/test-pthread-once2.c:
* tests/test-pthread-rwlock.c, tests/test-pthread-spin.c:
* tests/test-pthread-tss.c: Be consistent about casting
pthread_self to void *, by always casting via intptr_t first.
This pacifies -Wuseless-cast on GNU/Linux.

Pacify -Wuseless-cast via compound literals in tests

* tests/from-glibc/tst-stdbit.h (TEST_STDBIT_T):
* tests/jit/test-cache.c, tests/test-boot-time.c:
* tests/test-ceilf2.c, tests/test-fflush.c, tests/test-floorf2.c:
* tests/test-mbrtoc32-regular.c, tests/test-mbrtoc32.c:
* tests/test-mbrtowc-w32utf8.c, tests/test-mbrtowc.c:
* tests/test-mbsnrtoc32s.c, tests/test-mbsnrtowcs.c:
* tests/test-mbsrtoc32s.c, tests/test-mbsrtowcs.c:
* tests/test-mbstoc32s.c, tests/test-mbstowcs.c:
* tests/test-sameacls.c, tests/test-towctrans.c:
* tests/test-truncf2.c, tests/test-wcscmp.c, tests/test-wcsncmp.c:
* tests/test-wmemcmp.c:
(main)
* tests/test-c32isalnum.c, tests/test-c32isalpha.c:
* tests/test-c32isblank.c, tests/test-c32iscntrl.c:
* tests/test-c32isdigit.c, tests/test-c32isgraph.c:
* tests/test-c32islower.c, tests/test-c32isprint.c:
* tests/test-c32ispunct.c, tests/test-c32isspace.c:
* tests/test-c32isupper.c, tests/test-c32isxdigit.c:
* tests/test-c32tolower.c, tests/test-c32toupper.c:
* tests/test-iswdigit.c, tests/test-iswpunct.c, tests/test-iswxdigit.c:
(for_character):
* tests/test-c32rtomb.c, tests/test-wcrtomb.c:
(check_character):
* tests/test-mbrtoc32-w32.c, tests/test-mbrtowc-w32.c:
(test_one_locale):
* tests/test-snprintf-posix.h, tests/test-sprintf-posix.h:
* tests/test-vasnprintf-posix.c, tests/test-vasnwprintf-posix.c:
* tests/test-vasprintf-posix.c:
(test_function):
* tests/test-stat-time.c (initialize_filenames):
* tests/uniwidth/test-uc_width2.c (finish_interval):
Use compound literal when it is safer than a cast and it pacifies
-Wuseless-cast.  Also, omit unnecessary casts to a type when the
context is already that type and omitting pacifies -Wuseless-cast.

Pacify -Wuseless-cast via compound literals in lib

* lib/bitset.c (bitset_print):
* lib/bitset/list.c (LBITSET_ELT_BITS, debug_lbitset):
* lib/bitset/table.c (TBITSET_ELT_BITS):
* lib/bitsetv.c (bitsetv_dump, debug_bitsetv)
(bitsetv_matrix_dump):
* lib/gettext.h (gettext, ngettext, textdomain, bindtextdomain)
(bind_textdomain_codeset):
* lib/gl_anyavltree_list2.h (gl_tree_nx_add_first)
(gl_tree_nx_add_last, gl_tree_nx_add_before)
(gl_tree_nx_add_after):
* lib/gl_anylinked_list2.h (gl_linked_nx_create)
(gl_linked_node_nx_set_value, gl_linked_nx_set_at)
(gl_linked_search_from_to, gl_linked_indexof_from_to)
(gl_linked_nx_add_first, gl_linked_nx_add_last)
(gl_linked_nx_add_before, gl_linked_nx_add_after)
(gl_linked_nx_add_at):
* lib/gl_anyrbtree_list2.h (gl_tree_nx_add_first)
(gl_tree_nx_add_last, gl_tree_nx_add_before)
(gl_tree_nx_add_after):
* lib/gl_anytree_list2.h (gl_tree_node_nx_set_value)
(gl_tree_nx_set_at):
* lib/gl_anytreehash_list1.h (add_nodes_to_buckets):
* lib/gl_anytreehash_list2.h (gl_tree_search_from_to):
* lib/gl_array_list.c, lib/gl_carray_list.c, lib/gl_sublist.c:
(INDEX_TO_NODE):
* lib/gl_hash_map.c (gl_hash_search, gl_hash_nx_getput)
(gl_hash_getremove):
* lib/gl_hash_set.c (gl_hash_search, gl_hash_nx_add)
(gl_hash_remove):
* lib/gl_linkedhash_map.c (gl_linkedhash_search)
(gl_linkedhash_nx_getput, gl_linkedhash_getremove):
* lib/gl_linkedhash_set.c (gl_linkedhash_search)
(gl_linkedhash_nx_add, gl_linkedhash_remove):
* lib/isnand-nolibm.h (isnand):
* lib/isnanf-nolibm.h (isnanf):
* lib/isnanl-nolibm.h (isnanl):
* lib/math.in.h (isnand, _gl_isnand, isnan):
* lib/md4.c, lib/sha1.c:
(rol):
* lib/pagealign_alloc.c (pagealign_alloc, pagealign_free):
* lib/ssfmalloc.h (allocate_block_from_pool):
* lib/u64.h (u64hilo, u64lo, u64getlo) [INT_MAX < UINT64_MAX]:
Use compound literal when it is safer than a cast
and it pacifies -Wuseless-cast.
* lib/fsusage.c (PROPAGATE_ALL_ONES):
* lib/glthread/thread.h (glthread_atfork, glthread_sigmask):
Parenthesize more.
* lib/gettext.h (dgettext, dcgettext, dngettext, dcngettext)
(bindtextdomain, bind_textdomain_codeset):
Check types of unused args.

fstrcmp: pacify -Wuseless-cast

* lib/fstrcmp.c (fstrcmp_bounded): Omit unnecessary cast
of uintptr_t to uintptr_t.

argp: pacify -Wuseless-cast

* lib/argp-help.c (argp_doc): Omit unnecessary cast
of const char * to const char *.

manywarnings: avoid -Wuseless-cast warnings on GCC <= 13

* m4/manywarnings.m4: Only consider -Wuseless-cast on GCC >= 14
Fix suggested by Bruno Haible.

Revisit some -Wuseless-cast changes.

* lib/xsize.h (xtimes): Use a compound literal instead of sizeof "".

Revisit some -Wuseless-cast changes.

* lib/intprops-internal.h: Ignore -Wuseless-cast also with gcc 14, 15.
* lib/vasnprintf.c: Likewise. Also, fix a clang warning.

Revisit some -Wuseless-cast changes.

* lib/obstack.in.h (obstack_free): Restore parentheses around macro
argument.
* lib/printf-args.c (PRINTF_FETCHARGS): Do use wchar_t-typed constants.
* lib/vma-iter.c (rof_open): Revert last change. Warning now silenced
through gl_CC_GNULIB_WARNINGS.

Silence -Wuseless-cast in all Gnulib compilation units.

* m4/gnulib-common.m4 (gl_CC_GNULIB_WARNINGS): Add -Wno-useless-cast.

xsize: pacify -Wuseless-cast by ‘1 *’

* lib/xsize.h (xtimes): Instead of casting N to size_t,
widen it to size_t if it isn’t already wide enough.

Pacify -Wuseless cast with a pragma

* lib/intprops-internal.h: Ignore -Wuseless-cast.
* lib/vasnprintf.c: Ignore -Wuseless-cast.

Pacify GCC 16 -Wuseless-cast by omitting casts

* lib/obstack.in.h (obstack_free): Omit unnecessary cast.
* lib/printf-args.c (PRINTF_FETCHARGS): Omit unnecessary casts.
* lib/vma-iter.c (rof_open): Omit unnecessary casts.

full-write: pacify GCC 16 -Wkeyword-macro

* lib/full-write.c (const): Do not #define.  Instead, use CONST.
(CONST): New macro.
(full_rw): Omit unnecessary cast.

fts: pacify GCC 16 -Wfree-labels

Evidently those FALLTHROUGHs were put in to pacify an old
version of GCC, but that’s no longer needed and nowadays
is even counterproductive.
* lib/fts.c (FALLTHROUGH): Remove; no longer used.
(leaf_optimization): Remove the FALLTHROUGHs.
* modules/fts (Depends-on): Remove ‘attribute’.

maint: pacify -Wuseless-cast via compound literals

* lib/fsusage.c (PROPAGATE_ALL_ONES):
* lib/fts-cycle.c (AD_hash):
* lib/hash.c (hash_print_statistics, hash_print):
* lib/malloca.h (nmalloca):
* lib/readutmp.c (add_utmp):
* lib/xsize.h (xtimes):
When ((t) (E)) might provoke a -Wuseless-cast diagnostic in GCC 16,
use ((t) {E}) when that’s easy, i.e., when the expression is not
intended for use as a constant expression.

fpucw: pacify -Wuseless-cast

* lib/fpucw.h (SET_FPUCW, BEGIN_LONG_DOUBLE_ROUNDING): Pacify gcc
16 -Wuseless-cast by avoiding casts of void expressions to void.

regex-tests: work with wchar-single

* tests/test-regex-el.c, tests/test-regex-en.c, tests/test-regex-tr.c:
New files, containing the locale-specific parts of the old
tests/test-regex.c.
* modules/regex-tests (Files): Add them.  Add m4/locale-en.m4.
(configure.ac): Add gt_LOCALE_EN_UTF8.
(TESTS, check_PROGRAMS):
Add test-regex-el, test-regex-en, test-regex-tr.
(TESTS_ENVIRONMENT, test_regex_el_LDADD, test_regex_en_LDADD)
(test_regex_tr_LDADD): New macros.
* tests/test-regex.c: Do not include <locale.h>, <wctype.h>,
"localcharset.h".
(really_utf8): Remove.
(main):  Remove the parts assuming specific locales;
they are now moved to the abovementioned new files.

bench-tests: work with wchar-single

* modules/mbiter-bench-tests, modules/mbiterf-bench-tests:
* modules/mbswidth-bench-tests, modules/mbuiter-bench-tests:
* modules/mbuiterf-bench-tests, modules/mcel-bench-tests:
(Depends-on): Add streq.
* tests/bench-mbiter.c, tests/bench-mbiterf.c, tests/bench-mbswidth.c:
* tests/bench-mbuiter.c, tests/bench-mbuiterf.c, tests/bench-mcel.c:
If GNULIB_WCHAR_SINGLE_LOCALE, don’t call setlocale with different
locales.

regex-tests: fix usage of fastmap API

* tests/test-regex.c (main): Use documented fastmap API
rather than relying on undocumented behavior.

manywarnings: no ‘s’ at end of ‘-Wuseless-cast’

* m4/manywarnings.m4 (gl_MANYWARN_ALL_GCC): Fix typo in spelling
of ‘-Wuseless-cast’.  Found by gcc 16.1.1 20260501 (Red Hat 16.1.1-1).

stdckdint-h, stdcountof-h, uchar-h: Simplify for when C++ is not used.

Reported by Pádraig Brady in
<https://lists.gnu.org/archive/html/bug-gnulib/2026-05/msg00032.html>.

* m4/stdckdint_h.m4 (gl_STDCKDINT_H): When $CXX is empty, don't run C++
specific tests.
* m4/stdcountof_h.m4 (gl_STDCOUNTOF_H): Likewise.
* m4/uchar_h.m4 (gl_UCHAR_H): Likewise.

regex-tests: minor memory cleanup

* tests/test-regex.c (main): No need for regex to be static,
and making it auto is more likely to catch memory leaks in
debugging platforms.  Clean up after its last use.
Omit unnecessary setting/freeing of regs that doesn’t test anything.

pthread-h: Fix compilation error in C++ mode on mingw.

pthread-h: Fix compilation error in C++ mode.

Reported by Daiki Ueno.

* lib/pthread.in.h: Disable the 'using GNULIB_NAMESPACE::pthread_*'
directives for which the corresponding Gnulib module is not present.

regex: Fix compilation error with MSVC 2022.

* lib/cdefs.h (__restrict_arr): On MSVC, ignore __STDC_VERSION__.
* lib/regex.h (_Restrict_arr_): Likewise.

localeinfo: now LGPLv2+

* lib/localeinfo.h: Update license notice.
* lib/localeinfo.c: Likewise.

localeinfo: now LGPLv2+

* modules/localeinfo (License): Change from GPL,
since regex depends on it.

regex: fix glibc bug 20381

* lib/regcomp.c [!_LIBC]: Include localeinfo.h.
(re_set_fastmap): Remove icase arg, since it was not right
for initial bytes in multibyte locales.  Change ch arg to
be unsigned char so that callers need not cast.  All callers changed.
(re_set_fastmap_icase): New function.
(re_compile_fastmap_iter): Use it.
* modules/regex (Depends-on): Add localeinfo.
* tests/test-regex.c (main): Test for the bug.

localeinfo: port to single-byte non-__STDC_ISO_10646__

* lib/localeinfo.c (CHAR32_T_IS_UNICODE): New macro.
(case_folded_counterparts): In single-byte locales where
char32_t is not known to be Unicode, check all 255 possibilities
instead of hoping that char32_t is Unicode.
* lib/localeinfo.h (CASE_FOLDED_BUFSIZE): Increase to 255.
* modules/localeinfo (Depends-on): Add btoc32.

localeinfo: don’t check U+03F2 in newer glibc

* lib/localeinfo.c (lonesome_lower): Omit U+03F2 in recent Unicode.

localeinfo: add U+1C80 through U+1C88

* lib/localeinfo.c (lonesome_lower): Add U+1C80 through U+1C88,
which all have this property in Unicode 17.0.0.  For example,
U+1C80 CYRILLIC SMALL LETTER ROUNDED VE upcases to U+0412 CYRILLIC
CAPITAL LETTER VE which in turn downcases to U+0432 CYRILLIC SMALL
LETTER VE.

wchar-h: doc wchar_t limitations

* doc/posix-headers/wchar.texi: Mention which platforms don’t
use Unicode for wchar_t.