; Update from Gnulib

* configure.ac:

* src/conf_post.h: Remove workarounds now rendered redundant by
Gnulib.

16 files changed, 482 insertions, 46 deletions

diff --git a/m4/builtin-expect.m4 b/m4/builtin-expect.m4
index c7af926b34c..33f255e9f56 100644
--- a/m4/builtin-expect.m4
+++ b/m4/builtin-expect.m4
@@ -1,11 +1,11 @@
 # builtin-expect.m4
-# serial 1
+# serial 2
 dnl Copyright 2016-2024 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
 
-dnl Check for __builtin_expect.
+dnl Provide a GCC-compatible __builtin_expect macro in <config.h>.
 
 dnl Written by Paul Eggert.
 
diff --git a/m4/errno_h.m4 b/m4/errno_h.m4
index b6050e5d8e0..920ea6cc653 100644
--- a/m4/errno_h.m4
+++ b/m4/errno_h.m4
@@ -1,5 +1,5 @@
 # errno_h.m4
-# serial 14
+# serial 18
 dnl Copyright (C) 2004, 2006, 2008-2024 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -10,6 +10,11 @@ AC_PREREQ([2.61])
 AC_DEFUN_ONCE([gl_HEADER_ERRNO_H],
 [
   AC_REQUIRE([AC_PROG_CC])
+
+  dnl Through the dependency on module extensions-aix, _LINUX_SOURCE_COMPAT
+  dnl gets defined already before this macro gets invoked.  This persuades
+  dnl AIX 7.3 errno.h to assign ENOTEMPTY a value different than EEXIST.
+
   AC_CACHE_CHECK([for complete errno.h], [gl_cv_header_errno_h_complete], [
     AC_EGREP_CPP([booboo],[
 #include <errno.h>
@@ -64,6 +69,9 @@ booboo
 #if !defined EILSEQ
 booboo
 #endif
+#if !defined ESOCKTNOSUPPORT
+booboo
+#endif
       ],
       [gl_cv_header_errno_h_complete=no],
       [gl_cv_header_errno_h_complete=yes])
diff --git a/m4/extensions-aix.m4 b/m4/extensions-aix.m4
new file mode 100644
index 00000000000..990a7ac3ef0
--- /dev/null
+++ b/m4/extensions-aix.m4
@@ -0,0 +1,25 @@
+# extensions-aix.m4
+# serial 1
+dnl Copyright (C) 2024 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+# On AIX, most extensions are already enabled through the _ALL_SOURCE macro,
+# defined by gl_USE_SYSTEM_EXTENSIONS.  gl_USE_AIX_EXTENSIONS additionally
+# activates more GNU and Linux-like behaviours, affecting
+#   - the time_t type,
+#   - errno values in <errno.h>: ENOTEMPTY
+#   - functions in <stdlib.h>: malloc calloc realloc valloc
+#     <https://www.ibm.com/docs/en/aix/7.3?topic=m-malloc-free-realloc-calloc-mallopt-mallinfo-mallinfo-heap-alloca-valloc-posix-memalign-subroutine>
+#   - functions in <string.h>: strerror_r (returns 'char *', like glibc)
+#   - functions in <dirent.h>: scandir, alphasort, readdir_r
+#   - functions in <netdb.h>: gethostbyname_r gethostbyaddr_r
+#   - declarations in <unistd.h>: sbrk
+# and a couple of secondary <sys/*> header files.
+
+AC_DEFUN_ONCE([gl_USE_AIX_EXTENSIONS],
+[
+  AC_DEFINE([_LINUX_SOURCE_COMPAT], [1],
+    [Define so that AIX headers are more compatible with GNU/Linux.])
+])
diff --git a/m4/fchmodat.m4 b/m4/fchmodat.m4
index e71ee8e8ef6..99dcf58aa7a 100644
--- a/m4/fchmodat.m4
+++ b/m4/fchmodat.m4
@@ -1,5 +1,5 @@
 # fchmodat.m4
-# serial 8
+# serial 9
 dnl Copyright (C) 2004-2024 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -70,12 +70,12 @@ AC_DEFUN([gl_FUNC_FCHMODAT],
           esac
          ],
          [case "$host_os" in
-                                  # Guess no on Linux with glibc and Cygwin.
-            linux-gnu* | cygwin*) gl_cv_func_fchmodat_works="guessing no" ;;
-                                  # Guess 'nearly' on AIX.
-            aix*)                 gl_cv_func_fchmodat_works="guessing nearly" ;;
-                                  # If we don't know, obey --enable-cross-guesses.
-            *)                    gl_cv_func_fchmodat_works="$gl_cross_guess_normal" ;;
+                                   # Guess no on Linux with glibc and Cygwin.
+            linux*-gnu* | cygwin*) gl_cv_func_fchmodat_works="guessing no" ;;
+                                   # Guess 'nearly' on AIX.
+            aix*)                  gl_cv_func_fchmodat_works="guessing nearly" ;;
+                                   # If we don't know, obey --enable-cross-guesses.
+            *)                     gl_cv_func_fchmodat_works="$gl_cross_guess_normal" ;;
           esac
          ])
        rm -f conftest.fchmodat])
diff --git a/m4/fpieee.m4 b/m4/fpieee.m4
index 665543d0ed8..086d51ddf5b 100644
--- a/m4/fpieee.m4
+++ b/m4/fpieee.m4
@@ -1,5 +1,5 @@
 # fpieee.m4
-# serial 2  -*- coding: utf-8 -*-
+# serial 2
 dnl Copyright (C) 2007, 2009-2024 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
diff --git a/m4/gnulib-common.m4 b/m4/gnulib-common.m4
index 06dd6029759..d985522893f 100644
--- a/m4/gnulib-common.m4
+++ b/m4/gnulib-common.m4
@@ -1,5 +1,5 @@
 # gnulib-common.m4
-# serial 95
+# serial 103
 dnl Copyright (C) 2007-2024 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -21,10 +21,22 @@ AC_DEFUN([gl_COMMON_BODY], [
 #define _GL_CONFIG_H_INCLUDED 1
 ])
   AH_VERBATIM([_GL_GNUC_PREREQ],
-[/* True if the compiler says it groks GNU C version MAJOR.MINOR.  */
-#if defined __GNUC__ && defined __GNUC_MINOR__
+[/* True if the compiler says it groks GNU C version MAJOR.MINOR.
+    Except that
+      - clang groks GNU C 4.2, even on Windows, where it does not define
+        __GNUC__.
+      - The OpenMandriva-modified clang compiler pretends that it groks
+        GNU C version 13.1, but it doesn't: It does not support
+        __attribute__ ((__malloc__ (f, i))), nor does it support
+        __attribute__ ((__warning__ (message))) on a function redeclaration.
+      - Users can make clang lie as well, through the -fgnuc-version option.  */
+#if defined __GNUC__ && defined __GNUC_MINOR__ && !defined __clang__
 # define _GL_GNUC_PREREQ(major, minor) \
     ((major) < __GNUC__ + ((minor) <= __GNUC_MINOR__))
+#elif defined __clang__
+  /* clang really only groks GNU C 4.2.  */
+# define _GL_GNUC_PREREQ(major, minor) \
+    ((major) < 4 + ((minor) <= 2))
 #else
 # define _GL_GNUC_PREREQ(major, minor) 0
 #endif
@@ -133,6 +145,23 @@ AC_DEFUN([gl_COMMON_BODY], [
 # define _GL_HAVE___HAS_C_ATTRIBUTE 0
 #endif
 
+/* Attributes in bracket syntax [[...]] vs. attributes in __attribute__((...))
+   syntax, in function declarations.  There are two problems here.
+   (Last tested with gcc/g++ 14 and clang/clang++ 18.)
+
+   1) We want that the _GL_ATTRIBUTE_* can be cumulated on the same declaration
+      in any order.
+      =========================== foo.c = foo.cc ===========================
+      __attribute__ ((__deprecated__)) [[__nodiscard__]] int bar1 (int);
+      [[__nodiscard__]] __attribute__ ((__deprecated__)) int bar2 (int);
+      ======================================================================
+      This gives a syntax error
+        - in C mode with gcc
+          <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108796>, and
+        - in C++ mode with clang++ version < 16, and
+        - in C++ mode, inside extern "C" {}, still in newer clang++ versions
+          <https://github.com/llvm/llvm-project/issues/101990>.
+ */
 /* Define if, in a function declaration, the attributes in bracket syntax
    [[...]] must come before the attributes in __attribute__((...)) syntax.
    If this is defined, it is best to avoid the bracket syntax, so that the
@@ -147,6 +176,176 @@ AC_DEFUN([gl_COMMON_BODY], [
 #  define _GL_BRACKET_BEFORE_ATTRIBUTE 1
 # endif
 #endif
+/*
+   2) We want that the _GL_ATTRIBUTE_* can be placed in a declaration
+        - without 'extern', in C as well as in C++,
+        - with 'extern', in C,
+        - with 'extern "C"', in C++
+      in the same position.  That is, we don't want to be forced to use a
+      macro which arranges for the attribute to come before 'extern' in
+      one case and after 'extern' in the other case, because such a macro
+      would make the source code of .h files pretty ugly.
+      =========================== foo.c = foo.cc ===========================
+      #ifdef __cplusplus
+      # define CC "C"
+      #else
+      # define CC
+      #endif
+
+      #define ND   [[__nodiscard__]]
+      #define WUR  __attribute__((__warn_unused_result__))
+
+      #ifdef __cplusplus
+      extern "C" {
+      #endif
+                                        // gcc   clang  g++   clang++
+
+      ND int foo (int);
+      int ND foo (int);                 // warn  error  warn  error
+      int foo ND (int);
+      int foo (int) ND;                 // warn  error  warn  error
+
+      WUR int foo (int);
+      int WUR foo (int);
+      int fo1 WUR (int);                // error error  error error
+      int foo (int) WUR;
+
+      #ifdef __cplusplus
+      }
+      #endif
+
+                                        // gcc   clang  g++   clang++
+
+      ND extern CC int foo (int);       //              error error
+      extern CC ND int foo (int);       // error error
+      extern CC int ND foo (int);       // warn  error  warn  error
+      extern CC int foo ND (int);
+      extern CC int foo (int) ND;       // warn  error  warn  error
+
+      WUR extern CC int foo (int);      //              warn
+      extern CC WUR int foo (int);
+      extern CC int WUR foo (int);
+      extern CC int foo WUR (int);      // error error  error error
+      extern CC int foo (int) WUR;
+
+      ND EXTERN_C_FUNC int foo (int);   //              error error
+      EXTERN_C_FUNC ND int foo (int);
+      EXTERN_C_FUNC int ND foo (int);   // warn  error  warn  error
+      EXTERN_C_FUNC int foo ND (int);
+      EXTERN_C_FUNC int foo (int) ND;   // warn  error  warn  error
+
+      WUR EXTERN_C_FUNC int foo (int);  //              warn
+      EXTERN_C_FUNC WUR int foo (int);
+      EXTERN_C_FUNC int WUR foo (int);
+      EXTERN_C_FUNC int fo2 WUR (int);  // error error  error error
+      EXTERN_C_FUNC int foo (int) WUR;
+      ======================================================================
+      So, if we insist on using the 'extern' keyword ('extern CC' idiom):
+        * If _GL_ATTRIBUTE_* expands to bracket syntax [[...]]
+          in both C and C++, there is one available position:
+            - between the function name and the parameter list.
+        * If _GL_ATTRIBUTE_* expands to __attribute__((...)) syntax
+          in both C and C++, there are several available positions:
+            - before the return type,
+            - between return type and function name,
+            - at the end of the declaration.
+        * If _GL_ATTRIBUTE_* expands to bracket syntax [[...]] in C and to
+          __attribute__((...)) syntax in C++, there is no available position:
+          it would need to come before 'extern' in C but after 'extern "C"'
+          in C++.
+        * If _GL_ATTRIBUTE_* expands to __attribute__((...)) syntax in C and
+          to bracket syntax [[...]] in C++, there is one available position:
+            - before the return type.
+      Whereas, if we use the 'EXTERN_C_FUNC' idiom, which conditionally
+      omits the 'extern' keyword:
+        * If _GL_ATTRIBUTE_* expands to bracket syntax [[...]]
+          in both C and C++, there are two available positions:
+            - before the return type,
+            - between the function name and the parameter list.
+        * If _GL_ATTRIBUTE_* expands to __attribute__((...)) syntax
+          in both C and C++, there are several available positions:
+            - before the return type,
+            - between return type and function name,
+            - at the end of the declaration.
+        * If _GL_ATTRIBUTE_* expands to bracket syntax [[...]] in C and to
+          __attribute__((...)) syntax in C++, there is one available position:
+            - before the return type.
+        * If _GL_ATTRIBUTE_* expands to __attribute__((...)) syntax in C and
+          to bracket syntax [[...]] in C++, there is one available position:
+            - before the return type.
+      The best choice is therefore to use the 'EXTERN_C_FUNC' idiom and
+      put the attributes before the return type. This works regardless
+      to what the _GL_ATTRIBUTE_* macros expand.
+ */
+
+/* Attributes in bracket syntax [[...]] vs. attributes in __attribute__((...))
+   syntax, in static/inline function definitions.
+
+   There are similar constraints as for function declarations.  However, here,
+   we cannot omit the storage-class specifier.  Therefore, the following rule
+   applies:
+     * The macros
+         _GL_ATTRIBUTE_CONST
+         _GL_ATTRIBUTE_DEPRECATED
+         _GL_ATTRIBUTE_MAYBE_UNUSED
+         _GL_ATTRIBUTE_NODISCARD
+         _GL_ATTRIBUTE_PURE
+         _GL_ATTRIBUTE_REPRODUCIBLE
+         _GL_ATTRIBUTE_UNSEQUENCED
+       which may expand to bracket syntax [[...]], must come first, before the
+       storage-class specifier.
+     * Other _GL_ATTRIBUTE_* macros, that expand to __attribute__((...)) syntax,
+       are better placed between the storage-class specifier and the return
+       type.
+ */
+
+/* Attributes in bracket syntax [[...]] vs. attributes in __attribute__((...))
+   syntax, in variable declarations.
+
+   At which position can they be placed?
+   (Last tested with gcc/g++ 14 and clang/clang++ 18.)
+
+      =========================== foo.c = foo.cc ===========================
+      #ifdef __cplusplus
+      # define CC "C"
+      #else
+      # define CC
+      #endif
+
+      #define BD   [[__deprecated__]]
+      #define AD   __attribute__ ((__deprecated__))
+
+                              // gcc   clang  g++    clang++
+
+      BD extern CC int var;   //              error  error
+      extern CC BD int var;   // error error
+      extern CC int BD var;   // warn  error  warn   error
+      extern CC int var BD;
+
+      AD extern CC int var;   //              warn
+      extern CC AD int var;
+      extern CC int AD var;
+      extern CC int var AD;
+
+      BD extern CC int z[];   //              error  error
+      extern CC BD int z[];   // error error
+      extern CC int BD z[];   // warn  error  warn   error
+      extern CC int z1 BD [];
+      extern CC int z[] BD;   // warn  error         error
+
+      AD extern CC int z[];   //              warn
+      extern CC AD int z[];
+      extern CC int AD z[];
+      extern CC int z2 AD []; // error error  error  error
+      extern CC int z[] AD;
+      ======================================================================
+
+   * For non-array variables, the only good position is after the variable name,
+     that is, at the end of the declaration.
+   * For array variables, you will need to distinguish C and C++:
+       - In C, before the 'extern' keyword.
+       - In C++, between the 'extern "C"' and the variable's type.
+ */
 ]dnl There is no _GL_ATTRIBUTE_ALIGNED; use stdalign's alignas instead.
 [
 /* _GL_ATTRIBUTE_ALLOC_SIZE ((N)) declares that the Nth argument of the function
@@ -488,7 +687,7 @@ AC_DEFUN([gl_COMMON_BODY], [
    other attributes.  */
 #ifndef _GL_ATTRIBUTE_NOTHROW
 # if defined __cplusplus
-#  if _GL_GNUC_PREREQ (2, 8) || __clang_major >= 4
+#  if _GL_GNUC_PREREQ (2, 8) || __clang_major__ >= 4
 #   if __cplusplus >= 201103L
 #    define _GL_ATTRIBUTE_NOTHROW noexcept (true)
 #   else
@@ -1156,7 +1355,7 @@ AC_DEFUN([gl_CC_GNULIB_WARNINGS],
     dnl -Wno-unused-parameter                 >= 3            >= 3.9
     dnl
     cat > conftest.c <<\EOF
-      #if __GNUC__ >= 3 || (__clang_major__ + (__clang_minor__ >= 9) > 3)
+      #if (__GNUC__ >= 3 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3)
       -Wno-cast-qual
       -Wno-conversion
       -Wno-float-equal
@@ -1165,23 +1364,23 @@ AC_DEFUN([gl_CC_GNULIB_WARNINGS],
       -Wno-unused-function
       -Wno-unused-parameter
       #endif
-      #if __GNUC__ + (__GNUC_MINOR__ >= 9) > 4 || (__clang_major__ + (__clang_minor__ >= 9) > 3)
+      #if (__GNUC__ + (__GNUC_MINOR__ >= 9) > 4 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3)
       -Wno-float-conversion
       #endif
-      #if __GNUC__ >= 7 || (__clang_major__ + (__clang_minor__ >= 9) > 3)
+      #if (__GNUC__ >= 7 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3)
       -Wimplicit-fallthrough
       #endif
-      #if __GNUC__ + (__GNUC_MINOR__ >= 8) > 4 || (__clang_major__ + (__clang_minor__ >= 9) > 3)
+      #if (__GNUC__ + (__GNUC_MINOR__ >= 8) > 4 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3)
       -Wno-pedantic
       #endif
       #if 3 < __clang_major__ + (9 <= __clang_minor__)
       -Wno-tautological-constant-out-of-range-compare
       #endif
-      #if __GNUC__ + (__GNUC_MINOR__ >= 3) > 4 || (__clang_major__ + (__clang_minor__ >= 9) > 3)
+      #if (__GNUC__ + (__GNUC_MINOR__ >= 3) > 4 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3)
       -Wno-sign-conversion
       -Wno-type-limits
       #endif
-      #if __GNUC__ + (__GNUC_MINOR__ >= 5) > 4
+      #if (__GNUC__ + (__GNUC_MINOR__ >= 5) > 4 && !defined __clang__)
       -Wno-unsuffixed-float-constants
       #endif
 EOF
@@ -1364,7 +1563,7 @@ dnl
 dnl This macro sets two variables:
 dnl   - gl_cv_onwards_func_<func>   to yes / no / "future OS version"
 dnl   - ac_cv_func_<func>           to yes / no / no
-dnl The first variable allows distinguishing all three cases.
+dnl The first variable allows to distinguish all three cases.
 dnl The second variable is set, so that an invocation
 dnl   gl_CHECK_FUNCS_ANDROID([func], [[#include <foo.h>]])
 dnl can be used as a drop-in replacement for
@@ -1417,7 +1616,7 @@ dnl
 dnl This macro sets two variables:
 dnl   - gl_cv_onwards_func_<func>   to yes / no / "future OS version"
 dnl   - ac_cv_func_<func>           to yes / no / no
-dnl The first variable allows distinguishing all three cases.
+dnl The first variable allows to distinguish all three cases.
 dnl The second variable is set, so that an invocation
 dnl   gl_CHECK_FUNCS_MACOS([func], [[#include <foo.h>]])
 dnl can be used as a drop-in replacement for
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index 79a0f27382a..31784600d44 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -83,6 +83,10 @@ AC_DEFUN([gl_EARLY],
   # Code from module euidaccess:
   # Code from module execinfo:
   # Code from module extensions:
+  # This is actually already done in the pre-early phase.
+  # AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+  # Code from module extensions-aix:
+  AC_REQUIRE([gl_USE_AIX_EXTENSIONS])
   # Code from module extern-inline:
   # Code from module faccessat:
   # Code from module fchmodat:
@@ -129,6 +133,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module lchmod:
   # Code from module libc-config:
   # Code from module libgmp:
+  # Code from module libgmp-mpz:
   # Code from module limits-h:
   # Code from module lstat:
   # Code from module malloc-gnu:
@@ -339,6 +344,7 @@ AC_DEFUN([gl_INIT],
   gl_CONDITIONAL([GL_COND_OBJ_FSTATAT],
                  [test $HAVE_FSTATAT = 0 || test $REPLACE_FSTATAT = 1])
   gl_SYS_STAT_MODULE_INDICATOR([fstatat])
+  gl_MODULE_INDICATOR([fstatat])
   gl_FSUSAGE
   gl_CONDITIONAL([GL_COND_OBJ_FSUSAGE], [test $gl_cv_fs_space = yes])
   AM_COND_IF([GL_COND_OBJ_FSUSAGE], [
@@ -417,6 +423,7 @@ AC_DEFUN([gl_INIT],
     gl_PREREQ_LSTAT
   ])
   gl_SYS_STAT_MODULE_INDICATOR([lstat])
+  gl_MODULE_INDICATOR([lstat])
   gl_FUNC_MEMMEM_SIMPLE
   if test $HAVE_MEMMEM = 0 || test $REPLACE_MEMMEM = 1; then
     AC_LIBOBJ([memmem])
@@ -496,10 +503,12 @@ AC_DEFUN([gl_INIT],
     gl_PREREQ_REGEX
   ])
   gl_FUNC_SIG2STR
-  gl_CONDITIONAL([GL_COND_OBJ_SIG2STR], [test $ac_cv_func_sig2str = no])
+  gl_CONDITIONAL([GL_COND_OBJ_SIG2STR],
+                 [test $HAVE_SIG2STR = 0 || test $HAVE_STR2SIG = 0])
   AM_COND_IF([GL_COND_OBJ_SIG2STR], [
     gl_PREREQ_SIG2STR
   ])
+  gl_SIGNAL_MODULE_INDICATOR([sig2str])
   gl_FUNC_SIGDESCR_NP
   gl_CONDITIONAL([GL_COND_OBJ_SIGDESCR_NP], [test $HAVE_SIGDESCR_NP = 0])
   gl_STRING_MODULE_INDICATOR([sigdescr_np])
@@ -626,7 +635,8 @@ AC_DEFUN([gl_INIT],
   ])
   gl_TIME_MODULE_INDICATOR([time_r])
   gl_TIME_RZ
-  gl_CONDITIONAL([GL_COND_OBJ_TIME_RZ], [test $HAVE_TIMEZONE_T = 0])
+  gl_CONDITIONAL([GL_COND_OBJ_TIME_RZ],
+                 [test $HAVE_TZALLOC = 0 || test $REPLACE_LOCALTIME_RZ = 1 || test $REPLACE_MKTIME_Z = 1])
   gl_TIME_MODULE_INDICATOR([time_rz])
   gl_FUNC_TIMEGM
   gl_CONDITIONAL([GL_COND_OBJ_TIMEGM],
@@ -1521,6 +1531,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/errno_h.m4
   m4/euidaccess.m4
   m4/execinfo.m4
+  m4/extensions-aix.m4
   m4/extensions.m4
   m4/extern-inline.m4
   m4/faccessat.m4
@@ -1557,7 +1568,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/lchmod.m4
   m4/libgmp.m4
   m4/limits-h.m4
-  m4/locale-fr.m4
+  m4/locale-en.m4
   m4/lstat.m4
   m4/malloc.m4
   m4/manywarnings-c++.m4
diff --git a/m4/locale-en.m4 b/m4/locale-en.m4
new file mode 100644
index 00000000000..39d08a23b0b
--- /dev/null
+++ b/m4/locale-en.m4
@@ -0,0 +1,137 @@
+# locale-en.m4
+# serial 1
+dnl Copyright (C) 2003-2024 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+
+dnl Determine the name of an English (or American English) locale with
+dnl UTF-8 encoding.
+AC_DEFUN_ONCE([gt_LOCALE_EN_UTF8],
+[
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  AC_REQUIRE([AM_LANGINFO_CODESET])
+  AC_CACHE_CHECK([for an english Unicode locale], [gt_cv_locale_en_utf8], [
+    case "$host_os" in
+      *-musl* | midipix*)
+        dnl On musl libc, all kinds of ll_CC.UTF-8 locales exist, even without
+        dnl any locale file on disk. But they are effectively equivalent to the
+        dnl C.UTF-8 locale, except for locale categories (such as LC_MESSSAGES)
+        dnl for which localizations (.mo files) have been installed.
+        gt_cv_locale_en_utf8=en_US.UTF-8
+        ;;
+      *)
+        AC_LANG_CONFTEST([AC_LANG_SOURCE([[
+#include <locale.h>
+#include <time.h>
+#if HAVE_LANGINFO_CODESET
+# include <langinfo.h>
+#endif
+#include <stdlib.h>
+#include <string.h>
+struct tm t;
+char buf[16];
+int main () {
+  /* On BeOS and Haiku, locales are not implemented in libc.  Rather, libintl
+     imitates locale dependent behaviour by looking at the environment
+     variables, and all locales use the UTF-8 encoding.  */
+#if !(defined __BEOS__ || defined __HAIKU__)
+  /* Check whether the given locale name is recognized by the system.  */
+# if defined _WIN32 && !defined __CYGWIN__
+  /* On native Windows, setlocale(category, "") looks at the system settings,
+     not at the environment variables.  Also, when an encoding suffix such
+     as ".65001" or ".54936" is specified, it succeeds but sets the LC_CTYPE
+     category of the locale to "C".  */
+  if (setlocale (LC_ALL, getenv ("LC_ALL")) == NULL
+      || strcmp (setlocale (LC_CTYPE, NULL), "C") == 0)
+    return 1;
+# else
+  if (setlocale (LC_ALL, "") == NULL) return 1;
+# endif
+  /* Check whether nl_langinfo(CODESET) is "UTF-8" or equivalent.  */
+# if HAVE_LANGINFO_CODESET
+  {
+    const char *cs = nl_langinfo (CODESET);
+    if (!(strcmp (cs, "UTF-8") == 0 || strcmp (cs, "UTF8") == 0
+          || strcmp (cs, "utf-8") == 0 || strcmp (cs, "utf8") == 0))
+      return 1;
+  }
+# endif
+# ifdef __CYGWIN__
+  /* On Cygwin, avoid locale names without encoding suffix, because the
+     locale_charset() function relies on the encoding suffix.  Note that
+     LC_ALL is set on the command line.  */
+  if (strchr (getenv ("LC_ALL"), '.') == NULL) return 1;
+# endif
+  /* Check the third month name.  */
+  t.tm_year = 1975 - 1900; t.tm_mon = 3 - 1; t.tm_mday = 24;
+  if (strftime (buf, sizeof (buf), "%B", &t) < 5 || strcmp (buf, "March") != 0)
+    return 1;
+#endif
+#if !defined __BIONIC__ /* Bionic libc's 'struct lconv' is just a dummy.  */
+  /* Check whether the decimal separator is a dot.  */
+  if (localeconv () ->decimal_point[0] != '.') return 1;
+#endif
+  return 0;
+}
+          ]])])
+        if AC_TRY_EVAL([ac_link]) && test -s conftest$ac_exeext; then
+          case "$host_os" in
+            # Handle native Windows specially, because there setlocale() interprets
+            # "ar" or "ara" as "Arabic" or "Arabic_Saudi Arabia.1256",
+            # "en" or "eng" as "English" or "English_United States.1252",
+            # "fr" or "fra" as "French" or "French_France.1252",
+            # "ge"(!) or "deu"(!) as "German" or "German_Germany.1252",
+            # "ja" or "jpn" as "Japanese" or "Japanese_Japan.932",
+            # and similar.
+            mingw* | windows*)
+              # Test for the hypothetical native Windows locale name.
+              if (LC_ALL='English_United States.65001' LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
+                gt_cv_locale_en_utf8='English_United States.65001'
+              else
+                # None found.
+                gt_cv_locale_en_utf8=none
+              fi
+              ;;
+            *)
+              # Setting LC_ALL is not enough. Need to set LC_TIME to empty, because
+              # otherwise on Mac OS X 10.3.5 the LC_TIME=C from the beginning of the
+              # configure script would override the LC_ALL setting. Likewise for
+              # LC_CTYPE, which is also set at the beginning of the configure script.
+              # Test for the locale name with explicit encoding suffix first
+              # (this is necessary on Haiku).
+              if (LC_ALL=en_US.UTF-8 LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
+                gt_cv_locale_en_utf8=en_US.UTF-8
+              else
+                # Test for the locale name without encoding suffix.
+                if (LC_ALL=en_US LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
+                  gt_cv_locale_en_utf8=en_US
+                else
+                  # Test for the Solaris 10 locale name.
+                  if (LC_ALL=en.UTF-8 LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
+                    gt_cv_locale_en_utf8=en.UTF-8
+                  else
+                    # None found.
+                    gt_cv_locale_en_utf8=none
+                  fi
+                fi
+              fi
+              ;;
+          esac
+        fi
+        rm -fr conftest*
+        ;;
+    esac
+  ])
+  LOCALE_EN_UTF8="$gt_cv_locale_en_utf8"
+  case "$LOCALE_EN_UTF8" in #(
+    '' | *[[\"\$\'*@<:@]]*)
+      dnl The empty value occurs when the conftest.c program above could not
+      dnl be compiled.  The other values might cause trouble with sh or make.
+      AC_MSG_WARN([invalid locale "$LOCALE_EN_UTF8"; assuming "none"])
+      LOCALE_EN_UTF8=none;;
+  esac
+  AC_SUBST([LOCALE_EN_UTF8])
+])
diff --git a/m4/malloc.m4 b/m4/malloc.m4
index 41a46937ead..ee6df5c3fb6 100644
--- a/m4/malloc.m4
+++ b/m4/malloc.m4
@@ -1,5 +1,5 @@
 # malloc.m4
-# serial 31
+# serial 34
 dnl Copyright (C) 2007, 2009-2024 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -45,6 +45,11 @@ AC_DEFUN([gl_FUNC_MALLOC_GNU],
 [
   AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
   AC_REQUIRE([gl_FUNC_MALLOC_POSIX])
+
+  dnl Through the dependency on module extensions-aix, _LINUX_SOURCE_COMPAT
+  dnl gets defined already before this macro gets invoked.  This helps
+  dnl if !(__VEC__ || __AIXVEC), and doesn't hurt otherwise.
+
   REPLACE_MALLOC_FOR_MALLOC_GNU="$REPLACE_MALLOC_FOR_MALLOC_POSIX"
   if test $REPLACE_MALLOC_FOR_MALLOC_GNU = 0; then
     _AC_FUNC_MALLOC_IF([], [REPLACE_MALLOC_FOR_MALLOC_GNU=1])
diff --git a/m4/realloc.m4 b/m4/realloc.m4
index eb90d5885c7..cc91102836f 100644
--- a/m4/realloc.m4
+++ b/m4/realloc.m4
@@ -1,5 +1,5 @@
 # realloc.m4
-# serial 29
+# serial 32
 dnl Copyright (C) 2007, 2009-2024 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -45,6 +45,11 @@ AC_DEFUN([gl_FUNC_REALLOC_GNU],
 [
   AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
   AC_REQUIRE([gl_FUNC_REALLOC_POSIX])
+
+  dnl Through the dependency on module extensions-aix, _LINUX_SOURCE_COMPAT
+  dnl gets defined already before this macro gets invoked.  This helps
+  dnl if !(__VEC__ || __AIXVEC), and doesn't hurt otherwise.
+
   if test $REPLACE_REALLOC_FOR_REALLOC_GNU = 0; then
     _AC_FUNC_REALLOC_IF([], [REPLACE_REALLOC_FOR_REALLOC_GNU=1])
   fi
diff --git a/m4/sig2str.m4 b/m4/sig2str.m4
index 096d0253fcb..acef58a6a40 100644
--- a/m4/sig2str.m4
+++ b/m4/sig2str.m4
@@ -1,5 +1,5 @@
 # sig2str.m4
-# serial 7
+# serial 8
 dnl Copyright (C) 2002, 2005-2006, 2009-2024 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -7,7 +7,14 @@ dnl with or without modifications, as long as this notice is preserved.
 
 AC_DEFUN([gl_FUNC_SIG2STR],
 [
-  AC_CHECK_FUNCS([sig2str])
+  AC_REQUIRE([gl_SIGNAL_H_DEFAULTS])
+  AC_CHECK_FUNCS([sig2str str2sig])
+  if test $ac_cv_func_sig2str = no; then
+    HAVE_SIG2STR=0
+  fi
+  if test $ac_cv_func_str2sig = no; then
+    HAVE_STR2SIG=0
+  fi
 ])
 
 # Prerequisites of lib/sig2str.c.
diff --git a/m4/signal_h.m4 b/m4/signal_h.m4
index 65afa2a1dee..7a7d2b3c526 100644
--- a/m4/signal_h.m4
+++ b/m4/signal_h.m4
@@ -1,5 +1,5 @@
 # signal_h.m4
-# serial 22
+# serial 23
 dnl Copyright (C) 2007-2024 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -32,7 +32,8 @@ AC_DEFUN_ONCE([gl_SIGNAL_H],
   dnl Check for declarations of anything we want to poison if the
   dnl corresponding gnulib module is not in use.
   gl_WARN_ON_USE_PREPARE([[#include <signal.h>
-    ]], [pthread_sigmask sigaction
+    ]], [sig2str str2sig
+    pthread_sigmask sigaction
     sigaddset sigdelset sigemptyset sigfillset sigismember
     sigpending sigprocmask])
 
@@ -74,6 +75,7 @@ AC_DEFUN([gl_SIGNAL_H_REQUIRE_DEFAULTS],
   m4_defun(GL_MODULE_INDICATOR_PREFIX[_SIGNAL_H_MODULE_INDICATOR_DEFAULTS], [
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_PTHREAD_SIGMASK])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_RAISE])
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SIG2STR])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SIGNAL_H_SIGPIPE])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SIGPROCMASK])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SIGACTION])
@@ -88,9 +90,11 @@ AC_DEFUN([gl_SIGNAL_H_DEFAULTS],
   HAVE_POSIX_SIGNALBLOCKING=1; AC_SUBST([HAVE_POSIX_SIGNALBLOCKING])
   HAVE_PTHREAD_SIGMASK=1;      AC_SUBST([HAVE_PTHREAD_SIGMASK])
   HAVE_RAISE=1;                AC_SUBST([HAVE_RAISE])
+  HAVE_SIG2STR=1;              AC_SUBST([HAVE_SIG2STR])
   HAVE_SIGSET_T=1;             AC_SUBST([HAVE_SIGSET_T])
   HAVE_SIGINFO_T=1;            AC_SUBST([HAVE_SIGINFO_T])
   HAVE_SIGACTION=1;            AC_SUBST([HAVE_SIGACTION])
+  HAVE_STR2SIG=1;              AC_SUBST([HAVE_STR2SIG])
   HAVE_STRUCT_SIGACTION_SA_SIGACTION=1;
                                AC_SUBST([HAVE_STRUCT_SIGACTION_SA_SIGACTION])
   HAVE_TYPE_VOLATILE_SIG_ATOMIC_T=1;
diff --git a/m4/std-gnu11.m4 b/m4/std-gnu11.m4
index 37324c158e7..e8d5de7a1e1 100644
--- a/m4/std-gnu11.m4
+++ b/m4/std-gnu11.m4
@@ -1,8 +1,11 @@
 # std-gnu11.m4
-# serial 1
+# serial 2
 
 # Prefer GNU C11 and C++11 to earlier versions.  -*- coding: utf-8 -*-
 
+# The std-gnu23 module, which defines _AC_C_C23_OPTIONS, supersedes us.
+m4_ifndef([_AC_C_C23_OPTIONS], [
+
 # This implementation is taken from GNU Autoconf lib/autoconf/c.m4
 # commit 017d5ddd82854911f0119691d91ea8a1438824d6
 # dated Sun Apr 3 13:57:17 2016 -0700
@@ -38,7 +41,7 @@ m4_version_prereq([2.70], [], [
 # COMPILER ... is a space separated list of C compilers to search for.
 # This just gives the user an opportunity to specify an alternative
 # search list for the C compiler.
-AC_DEFUN_ONCE([AC_PROG_CC],
+AC_DEFUN([AC_PROG_CC],
 [AC_LANG_PUSH(C)dnl
 AC_ARG_VAR([CC],     [C compiler command])dnl
 AC_ARG_VAR([CFLAGS], [C compiler flags])dnl
@@ -830,3 +833,4 @@ dnl with extended modes being tried first.
 
 
 ])# m4_version_prereq
+])# !_AC_C_C23_OPTIONS
diff --git a/m4/stdlib_h.m4 b/m4/stdlib_h.m4
index bb5a6460414..5d9b3017c44 100644
--- a/m4/stdlib_h.m4
+++ b/m4/stdlib_h.m4
@@ -1,5 +1,5 @@
 # stdlib_h.m4
-# serial 78
+# serial 81
 dnl Copyright (C) 2007-2024 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -37,7 +37,7 @@ AC_DEFUN_ONCE([gl_STDLIB_H],
   dnl On Solaris 10, in UTF-8 locales, its value is 3 but needs to be 4.
   dnl Fortunately, we can do this because on this platform MB_LEN_MAX is 5.
   AC_REQUIRE([AC_CANONICAL_HOST])
-  AC_REQUIRE([gt_LOCALE_FR_UTF8])
+  AC_REQUIRE([gt_LOCALE_EN_UTF8])
   AC_CACHE_CHECK([whether MB_CUR_MAX is correct],
     [gl_cv_macro_MB_CUR_MAX_good],
     [
@@ -45,13 +45,13 @@ AC_DEFUN_ONCE([gl_STDLIB_H],
       dnl is present.
 changequote(,)dnl
       case "$host_os" in
-                  # Guess no on Solaris.
-        solaris*) gl_cv_macro_MB_CUR_MAX_good="guessing no" ;;
-                  # Guess yes otherwise.
-        *)        gl_cv_macro_MB_CUR_MAX_good="guessing yes" ;;
+                           # Guess no on Solaris and Haiku.
+        solaris* | haiku*) gl_cv_macro_MB_CUR_MAX_good="guessing no" ;;
+                           # Guess yes otherwise.
+        *)                 gl_cv_macro_MB_CUR_MAX_good="guessing yes" ;;
       esac
 changequote([,])dnl
-      if test $LOCALE_FR_UTF8 != none; then
+      if test "$LOCALE_EN_UTF8" != none; then
         AC_RUN_IFELSE(
           [AC_LANG_SOURCE([[
 #include <locale.h>
@@ -59,7 +59,7 @@ changequote([,])dnl
 int main ()
 {
   int result = 0;
-  if (setlocale (LC_ALL, "$LOCALE_FR_UTF8") != NULL)
+  if (setlocale (LC_ALL, "$LOCALE_EN_UTF8") != NULL)
     {
       if (MB_CUR_MAX < 4)
         result |= 1;
@@ -146,6 +146,7 @@ AC_DEFUN([gl_STDLIB_H_REQUIRE_DEFAULTS],
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_RPMATCH])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SECURE_GETENV])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SETENV])
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STACK_TRACE])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STRTOD])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STRTOF])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STRTOL])
@@ -261,4 +262,5 @@ AC_DEFUN([gl_STDLIB_H_DEFAULTS],
   REPLACE_STRTOULL=0;        AC_SUBST([REPLACE_STRTOULL])
   REPLACE_UNSETENV=0;        AC_SUBST([REPLACE_UNSETENV])
   REPLACE_WCTOMB=0;          AC_SUBST([REPLACE_WCTOMB])
+  CAN_PRINT_STACK_TRACE=0;   AC_SUBST([CAN_PRINT_STACK_TRACE])
 ])
diff --git a/m4/time_h.m4 b/m4/time_h.m4
index 4ca7305792c..88c76c03c02 100644
--- a/m4/time_h.m4
+++ b/m4/time_h.m4
@@ -1,5 +1,5 @@
 # time_h.m4
-# serial 26
+# serial 27
 dnl Copyright (C) 2000-2001, 2003-2007, 2009-2024 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -163,13 +163,16 @@ AC_DEFUN([gl_TIME_H_DEFAULTS],
   HAVE_TIMEGM=1;                         AC_SUBST([HAVE_TIMEGM])
   HAVE_TIMESPEC_GET=1;                   AC_SUBST([HAVE_TIMESPEC_GET])
   HAVE_TIMESPEC_GETRES=1;                AC_SUBST([HAVE_TIMESPEC_GETRES])
-  dnl Even GNU libc does not have timezone_t yet.
+  dnl Even GNU libc does not have timezone_t and tzalloc() yet.
   HAVE_TIMEZONE_T=0;                     AC_SUBST([HAVE_TIMEZONE_T])
+  HAVE_TZALLOC=0;                        AC_SUBST([HAVE_TZALLOC])
   REPLACE_CTIME=0;                       AC_SUBST([REPLACE_CTIME])
   REPLACE_GMTIME=0;                      AC_SUBST([REPLACE_GMTIME])
   REPLACE_LOCALTIME=0;                   AC_SUBST([REPLACE_LOCALTIME])
   REPLACE_LOCALTIME_R=0;                 AC_SUBST([REPLACE_LOCALTIME_R])
+  REPLACE_LOCALTIME_RZ=0;                AC_SUBST([REPLACE_LOCALTIME_RZ])
   REPLACE_MKTIME=0;                      AC_SUBST([REPLACE_MKTIME])
+  REPLACE_MKTIME_Z=0;                    AC_SUBST([REPLACE_MKTIME_Z])
   REPLACE_NANOSLEEP=0;                   AC_SUBST([REPLACE_NANOSLEEP])
   REPLACE_STRFTIME=0;                    AC_SUBST([REPLACE_STRFTIME])
   REPLACE_TIME=0;                        AC_SUBST([REPLACE_TIME])
diff --git a/m4/time_rz.m4 b/m4/time_rz.m4
index 9613597aca0..1a3dd3befb1 100644
--- a/m4/time_rz.m4
+++ b/m4/time_rz.m4
@@ -1,5 +1,5 @@
 # time_rz.m4
-# serial 2
+# serial 3
 dnl Copyright (C) 2015-2024 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -11,8 +11,9 @@ dnl Written by Paul Eggert.
 
 AC_DEFUN([gl_TIME_RZ],
 [
-  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
   AC_REQUIRE([gl_TIME_H_DEFAULTS])
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+  AC_REQUIRE([AC_CANONICAL_HOST])
 
   # On Mac OS X 10.6, localtime loops forever with some time_t values.
   # See Bug#27706, Bug#27736, and
@@ -51,4 +52,29 @@ AC_DEFUN([gl_TIME_RZ],
   if test "$ac_cv_type_timezone_t" = yes; then
     HAVE_TIMEZONE_T=1
   fi
+
+  gl_CHECK_FUNCS_ANDROID([tzalloc], [[#include <time.h>]])
+  if test $ac_cv_func_tzalloc = yes; then
+    HAVE_TZALLOC=1
+  fi
+  dnl Assume that tzalloc, localtime_rz, mktime_z are all defined together.
+  case "$gl_cv_onwards_func_tzalloc" in
+    yes)
+      case "$host_os" in
+        *-android*)
+          dnl The Android libc functions localtime_rz, mktime_z don't support
+          dnl a NULL timezone_t argument.
+          AC_DEFINE([NEED_TIMEZONE_NULL_SUPPORT], [1],
+            [Define to 1 if localtime_rz, mktime_z exist and can be used with
+             non-NULL timezone_t values.])
+          REPLACE_LOCALTIME_RZ=1
+          REPLACE_MKTIME_Z=1
+          ;;
+      esac
+      ;;
+    future*)
+      REPLACE_LOCALTIME_RZ=1
+      REPLACE_MKTIME_Z=1
+      ;;
+  esac
 ])