Merge remote-tracking branch 'origin/master' into feature/android

94 files changed, 1575 insertions, 540 deletions

diff --git a/admin/merge-gnulib b/admin/merge-gnulib
index 8065a9267d0..76e2a02558c 100755
--- a/admin/merge-gnulib
+++ b/admin/merge-gnulib
@@ -48,7 +48,7 @@ GNULIB_MODULES='
   stpcpy stpncpy strnlen strtoimax symlink sys_stat sys_time
   tempname time-h time_r time_rz timegm timer-time timespec-add timespec-sub
   update-copyright unlocked-io utimensat
-  vla warnings
+  vla warnings year2038
 '
 
 AVOIDED_MODULES='
@@ -137,5 +137,7 @@ cp -- "$gnulib_srcdir"/build-aux/config.guess \
 cp -- "$gnulib_srcdir"/lib/af_alg.h \
       "$gnulib_srcdir"/lib/save-cwd.h \
    "$src"lib &&
+cp -- "$gnulib_srcdir"/m4/codeset.m4 \
+   "$src"m4 &&
 { test -z "$src" || cd "$src"; } &&
 ./autogen.sh
diff --git a/configure.ac b/configure.ac
index 832e5a6bafd..65609ec8021 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1783,6 +1783,8 @@ AS_IF([test $gl_gcc_warnings = no],
   gl_WARN_ADD([-Wno-unused-parameter]) # Too many warnings for now
   gl_WARN_ADD([-Wno-format-nonliteral])
   gl_WARN_ADD([-Wno-bidi-chars])
+  AS_IF([test $gl_gcc_warnings = yes],
+    [gl_WARN_ADD([-Wno-analyzer-fd-leak])]) # GCC bug 109839
 
   # clang is unduly picky about some things.
   if test "$emacs_cv_clang" = yes; then
@@ -6269,29 +6271,21 @@ if test "${emacs_cv_links_glib}" = "yes"; then
 fi
 AC_SUBST([XGSELOBJ])
 
-dnl Adapted from Haible's version.
-AC_CACHE_CHECK([for nl_langinfo and CODESET], [emacs_cv_langinfo_codeset],
-  [AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <langinfo.h>]],
-    [[char *cs = nl_langinfo(CODESET);]])],
-    [emacs_cv_langinfo_codeset=yes],
-    [emacs_cv_langinfo_codeset=no])
-  ])
-if test "$emacs_cv_langinfo_codeset" = yes; then
-  AC_DEFINE([HAVE_LANGINFO_CODESET], [1],
-    [Define if you have <langinfo.h> and nl_langinfo (CODESET).])
-
-  AC_CACHE_CHECK([for nl_langinfo and _NL_PAPER_WIDTH],
-    [emacs_cv_langinfo__nl_paper_width],
-    [AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <langinfo.h>]],
-      [[char *cs = nl_langinfo (_NL_PAPER_WIDTH);]])],
-      [emacs_cv_langinfo__nl_paper_width=yes],
-      [emacs_cv_langinfo__nl_paper_width=no])
-    ])
-  if test "$emacs_cv_langinfo__nl_paper_width" = yes; then
-    AC_DEFINE([HAVE_LANGINFO__NL_PAPER_WIDTH], [1],
-      [Define if you have <langinfo.h> and nl_langinfo (_NL_PAPER_WIDTH).])
-  fi
-fi
+AC_DEFUN([EMACS_PAPER_WIDTH],
+  [AC_REQUIRE([AM_LANGINFO_CODESET])
+   AS_IF([test "$am_cv_langinfo_codeset" = yes],
+     [AC_CACHE_CHECK([for nl_langinfo and _NL_PAPER_WIDTH],
+	[emacs_cv_langinfo__nl_paper_width],
+	[AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <langinfo.h>]],
+	  [[char *cs = nl_langinfo (_NL_PAPER_WIDTH);]])],
+	  [emacs_cv_langinfo__nl_paper_width=yes],
+	  [emacs_cv_langinfo__nl_paper_width=no])
+	])
+      AS_IF([test "$emacs_cv_langinfo__nl_paper_width" = yes],
+	[AC_DEFINE([HAVE_LANGINFO__NL_PAPER_WIDTH], [1],
+	   [Define if you have <langinfo.h>
+	    and nl_langinfo (_NL_PAPER_WIDTH).])])])])
+EMACS_PAPER_WIDTH
 
 AC_TYPE_MBSTATE_T
 
diff --git a/doc/misc/texinfo.tex b/doc/misc/texinfo.tex
index 1ddfef4b878..a32c84197ae 100644
--- a/doc/misc/texinfo.tex
+++ b/doc/misc/texinfo.tex
@@ -3,7 +3,7 @@
 % Load plain if necessary, i.e., if running under initex.
 \expandafter\ifx\csname fmtname\endcsname\relax\input plain\fi
 %
-\def\texinfoversion{2023-03-04.12}
+\def\texinfoversion{2023-03-27.21}
 %
 % Copyright 1985, 1986, 1988, 1990-2023 Free Software Foundation, Inc.
 %
@@ -1102,27 +1102,33 @@ where each line of input produces a line of output.}
 
 % Output page labels information.
 % See PDF reference v.1.7 p.594, section 8.3.1.
+% Page label ranges must be increasing.
 \ifpdf
 \def\pagelabels{%
   \def\title{0 << /P (T-) /S /D >>}%
-  \edef\roman{\the\romancount << /S /r >>}%
-  \edef\arabic{\the\arabiccount << /S /D >>}%
   %
-  % Page label ranges must be increasing.  Remove any duplicates.
-  % (There is a slight chance of this being wrong if e.g. there is
-  % a @contents but no @titlepage, etc.)
-  %
-  \ifnum\romancount=0 \def\roman{}\fi
-  \ifnum\arabiccount=0 \def\title{}%
-  \else
-    \ifnum\romancount=\arabiccount \def\roman{}\fi
-  \fi
-  %
-  \ifnum\romancount<\arabiccount
-    \pdfcatalog{/PageLabels << /Nums [\title \roman \arabic ] >> }\relax
+  % support @contents at very end of document
+  \ifnum\contentsendcount=\pagecount
+    \ifnum\arabiccount<\romancount
+      \pdfcatalog{/PageLabels << /Nums
+                  [\title
+                   \the\arabiccount << /S /D >>
+                   \the\romancount << /S /r >>
+                  ] >> }\relax
+    \fi
+  % no contents in document
+  \else\ifnum\contentsendcount=0
+    \pdfcatalog{/PageLabels << /Nums
+                [\title
+                 \the\arabiccount << /S /D >>
+                ] >> }\relax
   \else
-    \pdfcatalog{/PageLabels << /Nums [\title \arabic \roman ] >> }\relax
-  \fi
+    \pdfcatalog{/PageLabels << /Nums
+                [\title
+                 \the\romancount << /S /r >>
+                 \the\contentsendcount << /S /D >>
+                ] >> }\relax
+  \fi\fi
 }
 \else
   \let\pagelabels\relax
@@ -1131,6 +1137,8 @@ where each line of input produces a line of output.}
 \newcount\pagecount \pagecount=0
 \newcount\romancount \romancount=0
 \newcount\arabiccount \arabiccount=0
+\newcount\contentsendcount \contentsendcount=0
+
 \ifpdf
   \let\ptxadvancepageno\advancepageno
   \def\advancepageno{%
@@ -4102,7 +4110,6 @@ $$%
     \nobreak\kern\dimen0
     \endgroup
     \itemxneedsnegativevskiptrue
-    \penalty 10021 % for \indexpar
   \fi
 }
 
@@ -4219,7 +4226,6 @@ $$%
    % We can be in inner vertical mode in a footnote, although an
    % @itemize looks awful there.
   }%
-  \penalty 10021 % for \indexpar
   \flushcr
 }
 
@@ -4784,17 +4790,11 @@ $$%
 % and it is the two-letter name of the index.
 
 \def\doindex#1{\edef\indexname{#1}\parsearg\doindexxxx}
-\def\doindexxxx #1{\indexpar\doind{\indexname}{#1}}
+\def\doindexxxx #1{\doind{\indexname}{#1}}
 
 % like the previous two, but they put @code around the argument.
 \def\docodeindex#1{\edef\indexname{#1}\parsearg\docodeindexxxx}
-\def\docodeindexxxx #1{\indexpar\docind{\indexname}{#1}}
-
-% End any open paragraph, unless we are immediately after @item in
-% @itemize or @enumerate.
-\def\indexpar{%
-\ifnum\lastpenalty=10021 \else\endgraf\fi
-}
+\def\docodeindexxxx #1{\docind{\indexname}{#1}}
 
 
 % \definedummyword defines \#1 as \string\#1\space, thus effectively
@@ -5351,9 +5351,7 @@ $$%
 % ..., ready, GO:
 %
 \def\safewhatsit#1{\ifhmode
-  \whatsitpenalty = \lastpenalty
   #1%
-  \ifnum\whatsitpenalty>9999 \penalty\whatsitpenalty \fi
  \else
   % \lastskip and \lastpenalty cannot both be nonzero simultaneously.
   \whatsitskip = \lastskip
@@ -6819,12 +6817,8 @@ might help (with 'rm \jobname.?? \jobname.??s')%
 % Get ready to use Arabic numerals again
 \def\contentsendroman{%
   \lastnegativepageno = \pageno
-  \global\pageno = \savepageno
-  %
-  % If \romancount > \arabiccount, the contents are at the end of the
-  % document.  Otherwise, advance where the Arabic numerals start for
-  % the page numbers.
-  \ifnum\romancount>\arabiccount\else\global\arabiccount=\pagecount\fi
+  \global\pageno=1
+  \contentsendcount = \pagecount
 }
 
 % Typeset the label for a chapter or appendix for the short contents.
@@ -7597,7 +7591,7 @@ might help (with 'rm \jobname.?? \jobname.??s')%
   \parseargusing\activeparens{\printdefunline\deflineheader}%
 }
 \def\deflineheader#1 #2 #3\endheader{%
-  \defname{#1}{}{#2}\magicamp\defunargs{#3\unskip}%
+  \printdefname{#1}{}{#2}\magicamp\defunargs{#3\unskip}%
 }
 \def\deftypeline{%
   \doingtypefntrue
@@ -7660,14 +7654,14 @@ might help (with 'rm \jobname.?? \jobname.??s')%
 % @deffn category name args
 \makedefun{deffn}#1 #2 #3\endheader{%
   \doind{fn}{\code{#2}}%
-  \defname{#1}{}{#2}\magicamp\defunargs{#3\unskip}%
+  \printdefname{#1}{}{#2}\magicamp\defunargs{#3\unskip}%
 }
 
 % @defop category class name args
 \makedefun{defop}#1 {\defopheaderx{#1\ \putwordon}}
 \def\defopheaderx#1#2 #3 #4\endheader{%
   \doind{fn}{\code{#3}\space\putwordon\ \code{#2}}%
-  \defname{#1\ \code{#2}}{}{#3}\magicamp\defunargs{#4\unskip}%
+  \printdefname{#1\ \code{#2}}{}{#3}\magicamp\defunargs{#4\unskip}%
 }
 
 % Typed functions:
@@ -7676,7 +7670,7 @@ might help (with 'rm \jobname.?? \jobname.??s')%
 \makedefun{deftypefn}#1 #2 #3 #4\endheader{%
   \doind{fn}{\code{#3}}%
   \doingtypefntrue
-  \defname{#1}{#2}{#3}\defunargs{#4\unskip}%
+  \printdefname{#1}{#2}{#3}\defunargs{#4\unskip}%
 }
 
 % @deftypeop category class type name args
@@ -7684,7 +7678,7 @@ might help (with 'rm \jobname.?? \jobname.??s')%
 \def\deftypeopheaderx#1#2 #3 #4 #5\endheader{%
   \doind{fn}{\code{#4}\space\putwordon\ \code{#1\ \code{#2}}}%
   \doingtypefntrue
-  \defname{#1\ \code{#2}}{#3}{#4}\defunargs{#5\unskip}%
+  \printdefname{#1\ \code{#2}}{#3}{#4}\defunargs{#5\unskip}%
 }
 
 % Typed variables:
@@ -7692,14 +7686,14 @@ might help (with 'rm \jobname.?? \jobname.??s')%
 % @deftypevr category type var args
 \makedefun{deftypevr}#1 #2 #3 #4\endheader{%
   \doind{vr}{\code{#3}}%
-  \defname{#1}{#2}{#3}\defunargs{#4\unskip}%
+  \printdefname{#1}{#2}{#3}\defunargs{#4\unskip}%
 }
 
 % @deftypecv category class type var args
 \makedefun{deftypecv}#1 {\deftypecvheaderx{#1\ \putwordof}}
 \def\deftypecvheaderx#1#2 #3 #4 #5\endheader{%
   \doind{vr}{\code{#4}\space\putwordof\ \code{#2}}%
-  \defname{#1\ \code{#2}}{#3}{#4}\defunargs{#5\unskip}%
+  \printdefname{#1\ \code{#2}}{#3}{#4}\defunargs{#5\unskip}%
 }
 
 % Untyped variables:
@@ -7716,7 +7710,7 @@ might help (with 'rm \jobname.?? \jobname.??s')%
 % @deftp category name args
 \makedefun{deftp}#1 #2 #3\endheader{%
   \doind{tp}{\code{#2}}%
-  \defname{#1}{}{#2}\defunargs{#3\unskip}%
+  \printdefname{#1}{}{#2}\defunargs{#3\unskip}%
 }
 
 % Remaining @defun-like shortcuts:
@@ -7732,14 +7726,14 @@ might help (with 'rm \jobname.?? \jobname.??s')%
 \makedefun{defivar}{\defcvheaderx\putwordInstanceVariableof}
 \makedefun{deftypeivar}{\deftypecvheaderx\putwordInstanceVariableof}
 
-% \defname, which formats the name of the @def (not the args).
+% \printdefname, which formats the name of the @def (not the args).
 % #1 is the category, such as "Function".
 % #2 is the return type, if any.
 % #3 is the function name.
 %
 % We are followed by (but not passed) the arguments, if any.
 %
-\def\defname#1#2#3{%
+\def\printdefname#1#2#3{%
   \par
   % Get the values of \leftskip and \rightskip as they were outside the @def...
   \advance\leftskip by -\defbodyindent
@@ -7864,7 +7858,7 @@ might help (with 'rm \jobname.?? \jobname.??s')%
 
 % If we encounter &foo, then turn on ()-hacking afterwards
 \newif\ifampseen
-\def\amprm#1 {\ampseentrue{\bf\&#1 }}
+\def\amprm#1 {\ampseentrue{\rm\&#1 }}
 
 \def\parenfont{%
   \ifampseen
@@ -8188,12 +8182,12 @@ might help (with 'rm \jobname.?? \jobname.??s')%
 %
 % We are in \macrobodyctxt, and the \xdef causes backslashshes in the macro
 % body to be transformed.
-% Set \macrobody to the body of the macro, and call \defmacro.
+% Set \macrobody to the body of the macro, and call \macrodef.
 %
 {\catcode`\ =\other\long\gdef\parsemacbody#1@end macro{%
-\xdef\macrobody{\eatcr{#1}}\endgroup\defmacro}}%
+\xdef\macrobody{\eatcr{#1}}\endgroup\macrodef}}%
 {\catcode`\ =\other\long\gdef\parsermacbody#1@end rmacro{%
-\xdef\macrobody{\eatcr{#1}}\endgroup\defmacro}}%
+\xdef\macrobody{\eatcr{#1}}\endgroup\macrodef}}%
 
 % Make @ a letter, so that we can make private-to-Texinfo macro names.
 \edef\texiatcatcode{\the\catcode`\@}
@@ -8412,16 +8406,17 @@ might help (with 'rm \jobname.?? \jobname.??s')%
 % \xdef is used so that macro definitions will survive the file
 % they're defined in: @include reads the file inside a group.
 %
-\def\defmacro{%
+\def\macrodef{%
   \let\hash=##% convert placeholders to macro parameter chars
   \ifnum\paramno=1
-    \def\xeatspaces##1{##1}%
-    % This removes the pair of braces around the argument.  We don't
-    % use \eatspaces, because this can cause ends of lines to be lost
-    % when the argument to \eatspaces is read, leading to line-based
-    % commands like "@itemize" not being read correctly.
+    \long\def\xeatspaces##1{##1}%
+    % We don't use \xeatspaces for single-argument macros, because we
+    % want to keep ends of lines.  This definition removes \xeatspaces
+    % when \macrobody is expanded below.
   \else
-    \let\xeatspaces\relax % suppress expansion
+    \def\xeatspaces{\string\xeatspaces}%
+    % This expands \xeatspaces as a sequence of character tokens, which
+    % stops \scantokens inserting an extra space after the control sequence.
   \fi
   \ifcase\paramno
   % 0
@@ -8590,40 +8585,35 @@ might help (with 'rm \jobname.?? \jobname.??s')%
 % @linemacro
 
 \parseargdef\linemacro{%
-  \linegetargs#1 \linegetargs
-  \expandafter\linegetparamlist\argl;%
+  \getargs{#1}% now \macname is the macname and \argl the arglist
+  \ifx\argl\empty
+    \paramno=0
+    \let\hash\relax
+    \def\paramlist{\hash 1\endlinemacro}%
+  \else
+    \expandafter\linegetparamlist\argl;%
+  \fi
   \begingroup \macrobodyctxt \usembodybackslash
   \parselinemacrobody
 }
 
-% Parse the arguments to a @linemacro line.  Set \macname to the name
-% of the macro and \argl to the list of arguments.
-\def\linegetargs#1 #2\linegetargs{%
-  \macname={#1}%
-  \def\argl{#2}%
-}
-
 % Build up \paramlist which will be used as the parameter text for the macro.
 % At the end it will be like "#1 #2 #3\endlinemacro".
 \def\linegetparamlist#1;{%
   \paramno=0\def\paramlist{}%
-  \let\hash\relax \let\xeatspaces\relax
-  \linegetparamlistxxx#1; %
+  \let\hash\relax
+  \linegetparamlistxxx#1,;,%
 }
-\def\linegetparamlistxxx#1 {%
+\def\linegetparamlistxxx#1,{%
   \if#1;\let\next=\linegetparamlistxxxx
   \else \let\next=\linegetparamlistxxx
     \advance\paramno by 1
     \expandafter\edef\csname macarg.\eatspaces{#1}\endcsname
-        {\noexpand\xeatspaces{\hash\the\paramno}}%
+        {\hash\the\paramno}%
     \edef\paramlist{\paramlist\hash\the\paramno\space}%
   \fi\next}
 \def\linegetparamlistxxxx{%
-  \ifx\paramlist\empty
-     \def\paramlist{\hash 1\endlinemacro}%
-  \else
-    \expandafter\fixparamlist\paramlist\fixparamlist
-  \fi
+  \expandafter\fixparamlist\paramlist\fixparamlist
 }
 % Replace final space token
 \def\fixparamlist#1 \fixparamlist{%
@@ -8633,7 +8623,6 @@ might help (with 'rm \jobname.?? \jobname.??s')%
 % Read the body of the macro, replacing backslash-surrounded variables
 %
 {\catcode`\ =\other\long\gdef\parselinemacrobody#1@end linemacro{%
-\let\xeatspaces\relax
 \xdef\macrobody{#1}%
 \endgroup
 \linemacrodef
@@ -8642,26 +8631,20 @@ might help (with 'rm \jobname.?? \jobname.??s')%
 % Make the definition
 \def\linemacrodef{%
   \let\hash=##%
-  \let\xeatspaces\relax
   \expandafter\xdef\csname\the\macname\endcsname{%
     \bgroup
-    \noexpand\scanctxt
     \noexpand\parsearg
     \expandafter\noexpand\csname\the\macname @@\endcsname
   }
   \expandafter\xdef\csname\the\macname @@\endcsname##1{%
     \egroup
     \expandafter\noexpand
-    \csname\the\macname @@@\endcsname##1 \noexpand\endlinemacro
-    % Note that we append a space to the macro line to terminate the last
-    % argument in case the final argument is empty.  @xeatspaces may be needed
-    % to remove this space.
+    \csname\the\macname @@@\endcsname##1\noexpand\endlinemacro
   }
   \expandafter\expandafter
   \expandafter\xdef
   \expandafter\expandafter\csname\the\macname @@@\endcsname\paramlist{%
     \newlinechar=13 % split \macrobody into lines
-    \let\noexpand\xeatspaces\noexpand\eatspaces
     \noexpand\scantokens{\macrobody}%
   }
 }
@@ -9659,8 +9642,8 @@ might help (with 'rm \jobname.?? \jobname.??s')%
 %
 \def\caption{\docaption\thiscaption}
 \def\shortcaption{\docaption\thisshortcaption}
-\def\docaption{\checkenv\float \bgroup\scanctxt\defcaption}
-\def\defcaption#1#2{\egroup \def#1{#2}}
+\def\docaption{\checkenv\float \bgroup\scanctxt\docaptionz}
+\def\docaptionz#1#2{\egroup \def#1{#2}}
 
 % The parameter is the control sequence identifying the counter we are
 % going to use.  Create it if it doesn't exist and assign it to \floatno.
diff --git a/lib-src/ebrowse.c b/lib-src/ebrowse.c
index 371fa6c938b..4b71f7447e0 100644
--- a/lib-src/ebrowse.c
+++ b/lib-src/ebrowse.c
@@ -3767,8 +3767,9 @@ main (int argc, char **argv)
 	  if (n_input_files == input_filenames_size)
 	    {
 	      input_filenames_size = max (10, 2 * input_filenames_size);
-	      input_filenames = (char **) xrealloc ((void *)input_filenames,
-						    input_filenames_size);
+	      input_filenames = xrealloc (input_filenames,
+					  (input_filenames_size
+					   * sizeof *input_filenames));
 	    }
           input_filenames[n_input_files++] = xstrdup (optarg);
           break;
diff --git a/lib-src/movemail.c b/lib-src/movemail.c
index a71be8c2099..6a772e9043e 100644
--- a/lib-src/movemail.c
+++ b/lib-src/movemail.c
@@ -470,7 +470,7 @@ main (int argc, char **argv)
 	     that were set on the file.  Better to just empty the file.  */
 	  if (unlink (inname) < 0 && errno != ENOENT)
 #endif /* MAIL_UNLINK_SPOOL */
-	    creat (inname, 0600);
+	    close (creat (inname, 0600));
 	}
 #endif /* not MAIL_USE_SYSTEM_LOCK */
 
diff --git a/lib/acl-internal.h b/lib/acl-internal.h
index c97e847cdc5..496e41d7b21 100644
--- a/lib/acl-internal.h
+++ b/lib/acl-internal.h
@@ -17,6 +17,11 @@
 
    Written by Paul Eggert, Andreas Grünbacher, and Bruno Haible.  */
 
+/* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE, _GL_ATTRIBUTE_PURE.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #include "acl.h"
 
 #include <stdlib.h>
@@ -60,9 +65,6 @@ extern int aclsort (int, int, struct acl *);
 # define fchmod(fd, mode) (-1)
 #endif
 
-#ifndef _GL_INLINE_HEADER_BEGIN
- #error "Please include config.h first."
-#endif
 _GL_INLINE_HEADER_BEGIN
 #ifndef ACL_INTERNAL_INLINE
 # define ACL_INTERNAL_INLINE _GL_INLINE
diff --git a/lib/acl.h b/lib/acl.h
index 58e5797179e..0d021200556 100644
--- a/lib/acl.h
+++ b/lib/acl.h
@@ -20,6 +20,11 @@
 #ifndef _GL_ACL_H
 #define _GL_ACL_H 1
 
+/* This file uses _GL_ATTRIBUTE_CONST.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #include <sys/types.h>
 #include <sys/stat.h>
 
diff --git a/lib/attribute.h b/lib/attribute.h
index 130644d8798..9464fde0f30 100644
--- a/lib/attribute.h
+++ b/lib/attribute.h
@@ -41,6 +41,21 @@
      These names begin with 'ATTRIBUTE_' to avoid name clashes.  */
 
 
+/* This file uses _GL_ATTRIBUTE_ALLOC_SIZE, _GL_ATTRIBUTE_ALWAYS_INLINE,
+   _GL_ATTRIBUTE_ARTIFICIAL, _GL_ATTRIBUTE_COLD, _GL_ATTRIBUTE_CONST,
+   _GL_ATTRIBUTE_DEALLOC, _GL_ATTRIBUTE_DEPRECATED, _GL_ATTRIBUTE_ERROR,
+   _GL_ATTRIBUTE_WARNING, _GL_ATTRIBUTE_EXTERNALLY_VISIBLE,
+   _GL_ATTRIBUTE_FALLTHROUGH, _GL_ATTRIBUTE_FORMAT, _GL_ATTRIBUTE_LEAF,
+   _GL_ATTRIBUTE_MALLOC, _GL_ATTRIBUTE_MAY_ALIAS, _GL_ATTRIBUTE_MAYBE_UNUSED,
+   _GL_ATTRIBUTE_NODISCARD, _GL_ATTRIBUTE_NOINLINE, _GL_ATTRIBUTE_NONNULL,
+   _GL_ATTRIBUTE_NONSTRING, _GL_ATTRIBUTE_NOTHROW, _GL_ATTRIBUTE_PACKED,
+   _GL_ATTRIBUTE_PURE, _GL_ATTRIBUTE_RETURNS_NONNULL,
+   _GL_ATTRIBUTE_SENTINEL.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
+
 /* =============== Attributes for specific kinds of functions =============== */
 
 /* Attributes for functions that should not be used.  */
diff --git a/lib/binary-io.h b/lib/binary-io.h
index 6f4db253354..855d6f819f0 100644
--- a/lib/binary-io.h
+++ b/lib/binary-io.h
@@ -17,6 +17,11 @@
 #ifndef _BINARY_H
 #define _BINARY_H
 
+/* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE, _GL_UNUSED.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 /* For systems that distinguish between text and binary I/O.
    O_BINARY is guaranteed by the gnulib <fcntl.h>. */
 #include <fcntl.h>
@@ -25,9 +30,6 @@
    so we include it here first.  */
 #include <stdio.h>
 
-#ifndef _GL_INLINE_HEADER_BEGIN
- #error "Please include config.h first."
-#endif
 _GL_INLINE_HEADER_BEGIN
 #ifndef BINARY_IO_INLINE
 # define BINARY_IO_INLINE _GL_INLINE
diff --git a/lib/c++defs.h b/lib/c++defs.h
index 8ad46951ad4..458c014de5c 100644
--- a/lib/c++defs.h
+++ b/lib/c++defs.h
@@ -99,6 +99,12 @@
    Example:
      _GL_FUNCDECL_RPL (open, int, (const char *filename, int flags, ...)
                                   _GL_ARG_NONNULL ((1)));
+
+   Note: Attributes, such as _GL_ATTRIBUTE_DEPRECATED, are supported in front
+   of a _GL_FUNCDECL_RPL invocation only in C mode, not in C++ mode.  (That's
+   because
+     [[...]] extern "C" <declaration>;
+   is invalid syntax in C++.)
  */
 #define _GL_FUNCDECL_RPL(func,rettype,parameters_and_attributes) \
   _GL_FUNCDECL_RPL_1 (rpl_##func, rettype, parameters_and_attributes)
diff --git a/lib/c-ctype.h b/lib/c-ctype.h
index 35ca83d7d43..cb0f4f3ba1f 100644
--- a/lib/c-ctype.h
+++ b/lib/c-ctype.h
@@ -23,9 +23,11 @@
 #ifndef C_CTYPE_H
 #define C_CTYPE_H
 
-#ifndef _GL_INLINE_HEADER_BEGIN
+/* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE.  */
+#if !_GL_CONFIG_H_INCLUDED
  #error "Please include config.h first."
 #endif
+
 _GL_INLINE_HEADER_BEGIN
 #ifndef C_CTYPE_INLINE
 # define C_CTYPE_INLINE _GL_INLINE
diff --git a/lib/c-strcase.h b/lib/c-strcase.h
index 9bcca01b27c..5dfa96c41f4 100644
--- a/lib/c-strcase.h
+++ b/lib/c-strcase.h
@@ -18,6 +18,11 @@
 #ifndef C_STRCASE_H
 #define C_STRCASE_H
 
+/* This file uses _GL_ATTRIBUTE_PURE.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #include <stddef.h>
 
 
diff --git a/lib/careadlinkat.h b/lib/careadlinkat.h
index 201d0415fff..562cf013b75 100644
--- a/lib/careadlinkat.h
+++ b/lib/careadlinkat.h
@@ -20,6 +20,11 @@
 #ifndef _GL_CAREADLINKAT_H
 #define _GL_CAREADLINKAT_H
 
+/* This file uses HAVE_READLINKAT.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #include <fcntl.h>
 #include <unistd.h>
 
diff --git a/lib/count-leading-zeros.h b/lib/count-leading-zeros.h
index 99151d695bf..9fe2a03ee09 100644
--- a/lib/count-leading-zeros.h
+++ b/lib/count-leading-zeros.h
@@ -19,12 +19,14 @@
 #ifndef COUNT_LEADING_ZEROS_H
 #define COUNT_LEADING_ZEROS_H 1
 
+/* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #include <limits.h>
 #include <stdlib.h>
 
-#ifndef _GL_INLINE_HEADER_BEGIN
- #error "Please include config.h first."
-#endif
 _GL_INLINE_HEADER_BEGIN
 #ifndef COUNT_LEADING_ZEROS_INLINE
 # define COUNT_LEADING_ZEROS_INLINE _GL_INLINE
diff --git a/lib/count-one-bits.h b/lib/count-one-bits.h
index 01a60b77b85..2821a1fb75e 100644
--- a/lib/count-one-bits.h
+++ b/lib/count-one-bits.h
@@ -19,12 +19,14 @@
 #ifndef COUNT_ONE_BITS_H
 #define COUNT_ONE_BITS_H 1
 
+/* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #include <limits.h>
 #include <stdlib.h>
 
-#ifndef _GL_INLINE_HEADER_BEGIN
- #error "Please include config.h first."
-#endif
 _GL_INLINE_HEADER_BEGIN
 #ifndef COUNT_ONE_BITS_INLINE
 # define COUNT_ONE_BITS_INLINE _GL_INLINE
diff --git a/lib/count-trailing-zeros.h b/lib/count-trailing-zeros.h
index ef8e164126a..9b33df76f6d 100644
--- a/lib/count-trailing-zeros.h
+++ b/lib/count-trailing-zeros.h
@@ -19,12 +19,14 @@
 #ifndef COUNT_TRAILING_ZEROS_H
 #define COUNT_TRAILING_ZEROS_H 1
 
+/* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #include <limits.h>
 #include <stdlib.h>
 
-#ifndef _GL_INLINE_HEADER_BEGIN
- #error "Please include config.h first."
-#endif
 _GL_INLINE_HEADER_BEGIN
 #ifndef COUNT_TRAILING_ZEROS_INLINE
 # define COUNT_TRAILING_ZEROS_INLINE _GL_INLINE
diff --git a/lib/dirent-private.h b/lib/dirent-private.h
new file mode 100644
index 00000000000..012b6837198
--- /dev/null
+++ b/lib/dirent-private.h
@@ -0,0 +1,67 @@
+/* Private details of the DIR type.
+   Copyright (C) 2011-2023 Free Software Foundation, Inc.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   This file is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#ifndef _DIRENT_PRIVATE_H
+#define _DIRENT_PRIVATE_H 1
+
+#if HAVE_DIRENT_H                       /* mingw */
+
+# undef DIR
+
+struct gl_directory
+{
+  /* File descriptor to close during closedir().
+     Needed for implementing fdopendir().  */
+  int fd_to_close;
+  /* Pointer to the real DIR.  */
+  DIR *real_dirp;
+};
+
+/* Restore definition from dirent.h.  */
+# define DIR struct gl_directory
+
+#else                                   /* MSVC */
+
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+
+/* Don't assume that UNICODE is not defined.  */
+# undef WIN32_FIND_DATA
+# define WIN32_FIND_DATA WIN32_FIND_DATAA
+
+struct gl_directory
+{
+  /* File descriptor to close during closedir().
+     Needed for implementing fdopendir().  */
+  int fd_to_close;
+  /* Status, or error code to produce in next readdir() call.
+     -2 means the end of the directory is already reached,
+     -1 means the entry was already filled by FindFirstFile,
+     0 means the entry needs to be filled using FindNextFile.
+     A positive value is an error code.  */
+  int status;
+  /* Handle, reading the directory, at current position.  */
+  HANDLE current;
+  /* Found directory entry.  */
+  WIN32_FIND_DATA entry;
+  /* Argument to pass to FindFirstFile.  It consists of the absolutized
+     directory name, followed by a directory separator and the wildcards.  */
+  char dir_name_mask[1];
+};
+
+#endif
+
+#endif /* _DIRENT_PRIVATE_H */
diff --git a/lib/dirent.in.h b/lib/dirent.in.h
index 2aaabd054a8..d409a031ec8 100644
--- a/lib/dirent.in.h
+++ b/lib/dirent.in.h
@@ -29,6 +29,12 @@
 #ifndef _@GUARD_PREFIX@_DIRENT_H
 #define _@GUARD_PREFIX@_DIRENT_H
 
+/* This file uses _GL_ATTRIBUTE_DEALLOC, _GL_ATTRIBUTE_MALLOC,
+   _GL_ATTRIBUTE_PURE, GNULIB_POSIXCHECK, HAVE_RAW_DECL_*.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 /* Get ino_t.  Needed on some systems, including glibc 2.8.  */
 #include <sys/types.h>
 
@@ -50,11 +56,24 @@ struct dirent
 #  define DT_LNK    10          /* symbolic link */
 #  define DT_SOCK   12          /* socket */
 #  define DT_WHT    14          /* whiteout */
-typedef struct gl_directory DIR;
 #  define GNULIB_defined_struct_dirent 1
 # endif
 #endif
 
+#if !@DIR_HAS_FD_MEMBER@
+# if !GNULIB_defined_DIR
+/* struct gl_directory is a type with a field 'int fd_to_close'.
+   It is needed for implementing fdopendir().  */
+struct gl_directory;
+#  if @HAVE_DIRENT_H@
+#   define DIR struct gl_directory
+#  else
+typedef struct gl_directory DIR;
+#  endif
+#  define GNULIB_defined_DIR 1
+# endif
+#endif
+
 /* _GL_ATTRIBUTE_DEALLOC (F, I) declares that the function returns pointers
    that can be freed by passing them as the Ith argument to the
    function F.  */
@@ -143,7 +162,7 @@ _GL_CXXALIAS_SYS (opendir, DIR *, (const char *dir_name));
 # endif
 _GL_CXXALIASWARN (opendir);
 #else
-# if @GNULIB_CLOSEDIR@ && __GNUC__ >= 11 && !defined opendir
+# if @GNULIB_CLOSEDIR@ && !GNULIB_defined_DIR && __GNUC__ >= 11 && !defined opendir
 /* For -Wmismatched-dealloc: Associate opendir with closedir or
    rpl_closedir.  */
 _GL_FUNCDECL_SYS (opendir, DIR *,
@@ -161,10 +180,19 @@ _GL_WARN_ON_USE (opendir, "opendir is not portable - "
 #endif
 
 #if @GNULIB_READDIR@
-# if !@HAVE_READDIR@
+# if @REPLACE_READDIR@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef readdir
+#   define readdir rpl_readdir
+#  endif
+_GL_FUNCDECL_RPL (readdir, struct dirent *, (DIR *dirp) _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (readdir, struct dirent *, (DIR *dirp));
+# else
+#  if !@HAVE_READDIR@
 _GL_FUNCDECL_SYS (readdir, struct dirent *, (DIR *dirp) _GL_ARG_NONNULL ((1)));
-# endif
+#  endif
 _GL_CXXALIAS_SYS (readdir, struct dirent *, (DIR *dirp));
+# endif
 _GL_CXXALIASWARN (readdir);
 #elif defined GNULIB_POSIXCHECK
 # undef readdir
@@ -175,10 +203,19 @@ _GL_WARN_ON_USE (readdir, "readdir is not portable - "
 #endif
 
 #if @GNULIB_REWINDDIR@
-# if !@HAVE_REWINDDIR@
+# if @REPLACE_REWINDDIR@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef rewinddir
+#   define rewinddir rpl_rewinddir
+#  endif
+_GL_FUNCDECL_RPL (rewinddir, void, (DIR *dirp) _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (rewinddir, void, (DIR *dirp));
+# else
+#  if !@HAVE_REWINDDIR@
 _GL_FUNCDECL_SYS (rewinddir, void, (DIR *dirp) _GL_ARG_NONNULL ((1)));
-# endif
+#  endif
 _GL_CXXALIAS_SYS (rewinddir, void, (DIR *dirp));
+# endif
 _GL_CXXALIASWARN (rewinddir);
 #elif defined GNULIB_POSIXCHECK
 # undef rewinddir
diff --git a/lib/dirfd.c b/lib/dirfd.c
index b2b1d25cdbd..75b2163c353 100644
--- a/lib/dirfd.c
+++ b/lib/dirfd.c
@@ -22,6 +22,10 @@
 #include <dirent.h>
 #include <errno.h>
 
+#if GNULIB_defined_DIR
+# include "dirent-private.h"
+#endif
+
 #ifdef __KLIBC__
 # include <stdlib.h>
 # include <io.h>
@@ -78,11 +82,17 @@ _gl_unregister_dirp_fd (int fd)
 int
 dirfd (DIR *dir_p)
 {
+#if GNULIB_defined_DIR
+  int fd = dir_p->fd_to_close;
+  if (fd == -1)
+    errno = EINVAL;
+  return fd;
+#else
   int fd = DIR_TO_FD (dir_p);
   if (fd == -1)
-#ifndef __KLIBC__
+# ifndef __KLIBC__
     errno = ENOTSUP;
-#else
+# else
     {
       struct dirp_fd_list *dirp_fd;
 
@@ -92,7 +102,8 @@ dirfd (DIR *dir_p)
 
       errno = EINVAL;
     }
-#endif
+# endif
 
   return fd;
+#endif
 }
diff --git a/lib/eloop-threshold.h b/lib/eloop-threshold.h
index 510f261795d..d9b154e4868 100644
--- a/lib/eloop-threshold.h
+++ b/lib/eloop-threshold.h
@@ -19,6 +19,11 @@
 #ifndef _ELOOP_THRESHOLD_H
 #define _ELOOP_THRESHOLD_H      1
 
+/* This file uses _GL_ATTRIBUTE_CONST.  */
+#if !_LIBC && !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #include <limits.h>
 #ifdef _LIBC
 # include <sys/param.h>
diff --git a/lib/execinfo.in.h b/lib/execinfo.in.h
index ff9293b6327..56b04d1d862 100644
--- a/lib/execinfo.in.h
+++ b/lib/execinfo.in.h
@@ -20,9 +20,11 @@
 #ifndef _GL_EXECINFO_H
 #define _GL_EXECINFO_H
 
-#ifndef _GL_INLINE_HEADER_BEGIN
+/* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE.  */
+#if !_GL_CONFIG_H_INCLUDED
  #error "Please include config.h first."
 #endif
+
 _GL_INLINE_HEADER_BEGIN
 #ifndef _GL_EXECINFO_INLINE
 # define _GL_EXECINFO_INLINE _GL_INLINE
diff --git a/lib/fcntl.in.h b/lib/fcntl.in.h
index e034eaf9f5a..d0bb85f30b5 100644
--- a/lib/fcntl.in.h
+++ b/lib/fcntl.in.h
@@ -74,6 +74,11 @@
 #ifndef _@GUARD_PREFIX@_FCNTL_H
 #define _@GUARD_PREFIX@_FCNTL_H
 
+/* This file uses GNULIB_POSIXCHECK, HAVE_RAW_DECL_*.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #ifndef __GLIBC__ /* Avoid namespace pollution on glibc systems.  */
 # include <unistd.h>
 #endif
diff --git a/lib/fdopendir.c b/lib/fdopendir.c
index aa841e3e819..0f43d6ff349 100644
--- a/lib/fdopendir.c
+++ b/lib/fdopendir.c
@@ -25,44 +25,27 @@
 
 #if !HAVE_FDOPENDIR
 
-# include "openat.h"
-# include "openat-priv.h"
-# include "save-cwd.h"
+# if GNULIB_defined_DIR
+/* We are in control of the file descriptor of a DIR.  */
 
-# if GNULIB_DIRENT_SAFER
-#  include "dirent--.h"
-# endif
-
-# ifndef REPLACE_FCHDIR
-#  define REPLACE_FCHDIR 0
-# endif
-
-static DIR *fdopendir_with_dup (int, int, struct saved_cwd const *);
-static DIR *fd_clone_opendir (int, struct saved_cwd const *);
-
-/* Replacement for POSIX fdopendir.
+#  include "dirent-private.h"
 
-   First, try to simulate it via opendir ("/proc/self/fd/...").  Failing
-   that, simulate it by using fchdir metadata, or by doing
-   save_cwd/fchdir/opendir(".")/restore_cwd.
-   If either the save_cwd or the restore_cwd fails (relatively unlikely),
-   then give a diagnostic and exit nonzero.
-
-   If successful, the resulting stream is based on FD in
-   implementations where streams are based on file descriptors and in
-   applications where no other thread or signal handler allocates or
-   frees file descriptors.  In other cases, consult dirfd on the result
-   to find out whether FD is still being used.
+#  if !REPLACE_FCHDIR
+#   error "unexpected configuration: GNULIB_defined_DIR but fchdir not replaced"
+#  endif
 
-   Otherwise, this function works just like POSIX fdopendir.
+DIR *
+fdopendir (int fd)
+{
+  char const *name = _gl_directory_name (fd);
+  DIR *dirp = name ? opendir (name) : NULL;
+  if (dirp != NULL)
+    dirp->fd_to_close = fd;
+  return dirp;
+}
 
-   W A R N I N G:
+# elif defined __KLIBC__
 
-   Unlike other fd-related functions, this one places constraints on FD.
-   If this function returns successfully, FD is under control of the
-   dirent.h system, and the caller should not close or modify the state of
-   FD other than by the dirent.h functions.  */
-# ifdef __KLIBC__
 #  include <InnoTekLIBC/backend.h>
 
 DIR *
@@ -96,7 +79,48 @@ fdopendir (int fd)
 
   return dirp;
 }
+
 # else
+/* We are not in control of the file descriptor of a DIR, and therefore have to
+   play tricks with file descriptors before and after a call to opendir().  */
+
+#  include "openat.h"
+#  include "openat-priv.h"
+#  include "save-cwd.h"
+
+#  if GNULIB_DIRENT_SAFER
+#   include "dirent--.h"
+#  endif
+
+#  ifndef REPLACE_FCHDIR
+#   define REPLACE_FCHDIR 0
+#  endif
+
+static DIR *fdopendir_with_dup (int, int, struct saved_cwd const *);
+static DIR *fd_clone_opendir (int, struct saved_cwd const *);
+
+/* Replacement for POSIX fdopendir.
+
+   First, try to simulate it via opendir ("/proc/self/fd/...").  Failing
+   that, simulate it by using fchdir metadata, or by doing
+   save_cwd/fchdir/opendir(".")/restore_cwd.
+   If either the save_cwd or the restore_cwd fails (relatively unlikely),
+   then give a diagnostic and exit nonzero.
+
+   If successful, the resulting stream is based on FD in
+   implementations where streams are based on file descriptors and in
+   applications where no other thread or signal handler allocates or
+   frees file descriptors.  In other cases, consult dirfd on the result
+   to find out whether FD is still being used.
+
+   Otherwise, this function works just like POSIX fdopendir.
+
+   W A R N I N G:
+
+   Unlike other fd-related functions, this one places constraints on FD.
+   If this function returns successfully, FD is under control of the
+   dirent.h system, and the caller should not close or modify the state of
+   FD other than by the dirent.h functions.  */
 DIR *
 fdopendir (int fd)
 {
@@ -119,7 +143,6 @@ fdopendir (int fd)
 
   return dir;
 }
-# endif
 
 /* Like fdopendir, except that if OLDER_DUPFD is not -1, it is known
    to be a dup of FD which is less than FD - 1 and which will be
@@ -188,7 +211,7 @@ fd_clone_opendir (int fd, struct saved_cwd const *cwd)
           if (proc_file != buf)
             free (proc_file);
         }
-# if REPLACE_FCHDIR
+#  if REPLACE_FCHDIR
       if (! dir && EXPECTED_ERRNO (saved_errno))
         {
           char const *name = _gl_directory_name (fd);
@@ -203,7 +226,7 @@ fd_clone_opendir (int fd, struct saved_cwd const *cwd)
 
           return dp;
         }
-# endif
+#  endif
       errno = saved_errno;
       return dir;
     }
@@ -223,6 +246,8 @@ fd_clone_opendir (int fd, struct saved_cwd const *cwd)
     }
 }
 
+# endif
+
 #else /* HAVE_FDOPENDIR */
 
 # include <errno.h>
diff --git a/lib/file-has-acl.c b/lib/file-has-acl.c
index b31a2ea2523..38bc806dc49 100644
--- a/lib/file-has-acl.c
+++ b/lib/file-has-acl.c
@@ -29,7 +29,7 @@
 
 #include "acl-internal.h"
 
-#if USE_ACL && GETXATTR_WITH_POSIX_ACLS
+#if USE_ACL && HAVE_LINUX_XATTR_H && HAVE_LISTXATTR
 # include <string.h>
 # include <arpa/inet.h>
 # include <sys/xattr.h>
@@ -44,6 +44,20 @@ enum {
   ACE4_IDENTIFIER_GROUP        = 0x00000040
 };
 
+/* Return true if ATTR is in the set represented by the NUL-terminated
+   strings in LISTBUF, which is of size LISTSIZE.  */
+
+static bool
+have_xattr (char const *attr, char const *listbuf, ssize_t listsize)
+{
+  char const *blim = listbuf + listsize;
+  for (char const *b = listbuf; b < blim; b += strlen (b) + 1)
+    for (char const *a = attr; *a == *b; a++, b++)
+      if (!*a)
+        return true;
+  return false;
+}
+
 /* Return 1 if given ACL in XDR format is non-trivial, 0 if it is trivial.
    -1 upon failure to determine it.  Possibly change errno.  Assume that
    the ACL is valid, except avoid undefined behavior even if invalid.
@@ -137,37 +151,65 @@ file_has_acl (char const *name, struct stat const *sb)
   if (! S_ISLNK (sb->st_mode))
     {
 
-# if GETXATTR_WITH_POSIX_ACLS
-
-      ssize_t ret;
+# if HAVE_LINUX_XATTR_H && HAVE_LISTXATTR
       int initial_errno = errno;
 
-      ret = getxattr (name, XATTR_NAME_POSIX_ACL_ACCESS, NULL, 0);
-      if (ret < 0 && errno == ENODATA)
-        ret = 0;
-      else if (ret > 0)
-        return 1;
-
-      if (ret == 0 && S_ISDIR (sb->st_mode))
+      /* The max length of a trivial NFSv4 ACL is 6 words for owner,
+         6 for group, 7 for everyone, all times 2 because there are
+         both allow and deny ACEs.  There are 6 words for owner
+         because of type, flag, mask, wholen, "OWNER@"+pad and
+         similarly for group; everyone is another word to hold
+         "EVERYONE@".  */
+      typedef uint32_t trivial_NFSv4_xattr_buf[2 * (6 + 6 + 7)];
+
+      /* A buffer large enough to hold any trivial NFSv4 ACL,
+         and also useful as a small array of char.  */
+      union {
+        trivial_NFSv4_xattr_buf xattr;
+        char ch[sizeof (trivial_NFSv4_xattr_buf)];
+      } stackbuf;
+
+      char *listbuf = stackbuf.ch;
+      ssize_t listbufsize = sizeof stackbuf.ch;
+      char *heapbuf = NULL;
+      ssize_t listsize;
+
+      /* Use listxattr first, as this means just one syscall in the
+         typical case where the file lacks an ACL.  Try stackbuf
+         first, falling back on malloc if stackbuf is too small.  */
+      while ((listsize = listxattr (name, listbuf, listbufsize)) < 0
+             && errno == ERANGE)
         {
-          ret = getxattr (name, XATTR_NAME_POSIX_ACL_DEFAULT, NULL, 0);
-          if (ret < 0 && errno == ENODATA)
-            ret = 0;
-          else if (ret > 0)
-            return 1;
+          free (heapbuf);
+          listbufsize = listxattr (name, NULL, 0);
+          if (listbufsize < 0)
+            return -1;
+          if (SIZE_MAX < listbufsize)
+            {
+              errno = ENOMEM;
+              return -1;
+            }
+          listbuf = heapbuf = malloc (listbufsize);
+          if (!listbuf)
+            return -1;
         }
 
-      if (ret < 0)
+      int ret
+        = (listsize < 0 ? -1
+           : (have_xattr (XATTR_NAME_POSIX_ACL_ACCESS, listbuf, listsize)
+              || (S_ISDIR (sb->st_mode)
+                  && have_xattr (XATTR_NAME_POSIX_ACL_DEFAULT,
+                                 listbuf, listsize))));
+      bool nfsv4_acl_but_no_posix_acl
+        = ret == 0 && have_xattr (XATTR_NAME_NFSV4_ACL, listbuf, listsize);
+      free (heapbuf);
+
+      /* If there is an NFSv4 ACL but no POSIX ACL, follow up with a
+         getxattr syscall to see whether the NFSv4 ACL is nontrivial.  */
+      if (nfsv4_acl_but_no_posix_acl)
         {
-          /* Check for NFSv4 ACLs.  The max length of a trivial
-             ACL is 6 words for owner, 6 for group, 7 for everyone,
-             all times 2 because there are both allow and deny ACEs.
-             There are 6 words for owner because of type, flag, mask,
-             wholen, "OWNER@"+pad and similarly for group; everyone is
-             another word to hold "EVERYONE@".  */
-          uint32_t xattr[2 * (6 + 6 + 7)];
-
-          ret = getxattr (name, XATTR_NAME_NFSV4_ACL, xattr, sizeof xattr);
+          ret = getxattr (name, XATTR_NAME_NFSV4_ACL,
+                          stackbuf.xattr, sizeof stackbuf.xattr);
           if (ret < 0)
             switch (errno)
               {
@@ -177,7 +219,7 @@ file_has_acl (char const *name, struct stat const *sb)
           else
             {
               /* It looks like a trivial ACL, but investigate further.  */
-              ret = acl_nfs4_nontrivial (xattr, ret);
+              ret = acl_nfs4_nontrivial (stackbuf.xattr, ret);
               if (ret < 0)
                 {
                   errno = EINVAL;
diff --git a/lib/filemode.h b/lib/filemode.h
index 15a8dcc3760..3e1d9903eac 100644
--- a/lib/filemode.h
+++ b/lib/filemode.h
@@ -17,6 +17,12 @@
    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #ifndef FILEMODE_H_
+# define FILEMODE_H_
+
+/* This file uses HAVE_DECL_STRMODE.  */
+# if !_GL_CONFIG_H_INCLUDED
+#  error "Please include config.h first."
+# endif
 
 # include <sys/types.h>
 # include <sys/stat.h>
diff --git a/lib/filevercmp.h b/lib/filevercmp.h
index 6b81ab32a7f..9e052bdd08c 100644
--- a/lib/filevercmp.h
+++ b/lib/filevercmp.h
@@ -20,6 +20,11 @@
 #ifndef FILEVERCMP_H
 #define FILEVERCMP_H
 
+/* This file uses _GL_ATTRIBUTE_PURE.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #include <stddef.h>
 
 /* Compare strings A and B as file names containing version numbers,
diff --git a/lib/flexmember.h b/lib/flexmember.h
index a6cc876a6d5..8c5915ecf9c 100644
--- a/lib/flexmember.h
+++ b/lib/flexmember.h
@@ -20,6 +20,11 @@
 
    Written by Paul Eggert.  */
 
+/* This file uses _Alignof.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #include <stddef.h>
 
 /* Nonzero multiple of alignment of TYPE, suitable for FLEXSIZEOF below.
diff --git a/lib/fpending.h b/lib/fpending.h
index 5e860db6810..1604ca0b7af 100644
--- a/lib/fpending.h
+++ b/lib/fpending.h
@@ -18,6 +18,12 @@
 
    Written by Jim Meyering.  */
 
+/* This file uses _GL_ATTRIBUTE_PURE, HAVE_STDIO_EXT_H,
+   HAVE_DECL___FPENDING.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #include <stddef.h>
 #include <stdio.h>
 #if HAVE_STDIO_EXT_H
diff --git a/lib/gnulib.mk.in b/lib/gnulib.mk.in
index 94fd1d5bec9..e447a2c4054 100644
--- a/lib/gnulib.mk.in
+++ b/lib/gnulib.mk.in
@@ -171,7 +171,8 @@
 #  utimensat \
 #  vasprintf-posix \
 #  vla \
-#  warnings
+#  warnings \
+#  year2038
 
 
 MOSTLYCLEANFILES += core *.stackdump
@@ -240,6 +241,7 @@ DBUS_LIBS = @DBUS_LIBS@
 DBUS_OBJ = @DBUS_OBJ@
 DEFS = @DEFS@
 DESLIB = @DESLIB@
+DIR_HAS_FD_MEMBER = @DIR_HAS_FD_MEMBER@
 DOCMISC_W32 = @DOCMISC_W32@
 DUMPING = @DUMPING@
 DYNAMIC_LIB_SECONDARY_SUFFIX = @DYNAMIC_LIB_SECONDARY_SUFFIX@
@@ -543,6 +545,7 @@ GL_GNULIB_MBSSEP = @GL_GNULIB_MBSSEP@
 GL_GNULIB_MBSSPN = @GL_GNULIB_MBSSPN@
 GL_GNULIB_MBSSTR = @GL_GNULIB_MBSSTR@
 GL_GNULIB_MBSTOK_R = @GL_GNULIB_MBSTOK_R@
+GL_GNULIB_MBSTOWCS = @GL_GNULIB_MBSTOWCS@
 GL_GNULIB_MBTOWC = @GL_GNULIB_MBTOWC@
 GL_GNULIB_MDA_ACCESS = @GL_GNULIB_MDA_ACCESS@
 GL_GNULIB_MDA_CHDIR = @GL_GNULIB_MDA_CHDIR@
@@ -858,6 +861,7 @@ HAVE_DECL_MEMMEM = @HAVE_DECL_MEMMEM@
 HAVE_DECL_MEMRCHR = @HAVE_DECL_MEMRCHR@
 HAVE_DECL_OBSTACK_PRINTF = @HAVE_DECL_OBSTACK_PRINTF@
 HAVE_DECL_POSIX_SPAWN_SETSID = @HAVE_DECL_POSIX_SPAWN_SETSID@
+HAVE_DECL_PROGRAM_INVOCATION_NAME = @HAVE_DECL_PROGRAM_INVOCATION_NAME@
 HAVE_DECL_PUTW = @HAVE_DECL_PUTW@
 HAVE_DECL_REMAINDER = @HAVE_DECL_REMAINDER@
 HAVE_DECL_REMAINDERL = @HAVE_DECL_REMAINDERL@
@@ -1189,6 +1193,7 @@ LIB_WSOCK32 = @LIB_WSOCK32@
 LIB_XATTR = @LIB_XATTR@
 LIMITS_H = @LIMITS_H@
 LN_S_FILEONLY = @LN_S_FILEONLY@
+LOCALE_FR_UTF8 = @LOCALE_FR_UTF8@
 LTLIBGMP = @LTLIBGMP@
 LTLIBINTL = @LTLIBINTL@
 LTLIBOBJS = @LTLIBOBJS@
@@ -1434,7 +1439,9 @@ REPLACE_LSEEK = @REPLACE_LSEEK@
 REPLACE_LSTAT = @REPLACE_LSTAT@
 REPLACE_MALLOC_FOR_MALLOC_GNU = @REPLACE_MALLOC_FOR_MALLOC_GNU@
 REPLACE_MALLOC_FOR_MALLOC_POSIX = @REPLACE_MALLOC_FOR_MALLOC_POSIX@
+REPLACE_MBSTOWCS = @REPLACE_MBSTOWCS@
 REPLACE_MBTOWC = @REPLACE_MBTOWC@
+REPLACE_MB_CUR_MAX = @REPLACE_MB_CUR_MAX@
 REPLACE_MEMCHR = @REPLACE_MEMCHR@
 REPLACE_MEMMEM = @REPLACE_MEMMEM@
 REPLACE_MEMPCPY = @REPLACE_MEMPCPY@
@@ -1475,6 +1482,7 @@ REPLACE_RAISE = @REPLACE_RAISE@
 REPLACE_RANDOM = @REPLACE_RANDOM@
 REPLACE_RANDOM_R = @REPLACE_RANDOM_R@
 REPLACE_READ = @REPLACE_READ@
+REPLACE_READDIR = @REPLACE_READDIR@
 REPLACE_READLINK = @REPLACE_READLINK@
 REPLACE_READLINKAT = @REPLACE_READLINKAT@
 REPLACE_REALLOCARRAY = @REPLACE_REALLOCARRAY@
@@ -1487,7 +1495,11 @@ REPLACE_REMAINDERL = @REPLACE_REMAINDERL@
 REPLACE_REMOVE = @REPLACE_REMOVE@
 REPLACE_RENAME = @REPLACE_RENAME@
 REPLACE_RENAMEAT = @REPLACE_RENAMEAT@
+<<<<<<< HEAD
 REPLACE_RINTL = @REPLACE_RINTL@
+=======
+REPLACE_REWINDDIR = @REPLACE_REWINDDIR@
+>>>>>>> origin/master
 REPLACE_RMDIR = @REPLACE_RMDIR@
 REPLACE_ROUND = @REPLACE_ROUND@
 REPLACE_ROUNDF = @REPLACE_ROUNDF@
@@ -2074,6 +2086,7 @@ dirent.h: dirent.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H
 	      -e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
 	      -e 's|@''PRAGMA_COLUMNS''@|@PRAGMA_COLUMNS@|g' \
 	      -e 's|@''NEXT_DIRENT_H''@|$(NEXT_DIRENT_H)|g' \
+	      -e 's/@''DIR_HAS_FD_MEMBER''@/$(DIR_HAS_FD_MEMBER)/g' \
 	      -e 's/@''GNULIB_OPENDIR''@/$(GL_GNULIB_OPENDIR)/g' \
 	      -e 's/@''GNULIB_READDIR''@/$(GL_GNULIB_READDIR)/g' \
 	      -e 's/@''GNULIB_REWINDDIR''@/$(GL_GNULIB_REWINDDIR)/g' \
@@ -2092,6 +2105,8 @@ dirent.h: dirent.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H
 	      -e 's|@''HAVE_SCANDIR''@|$(HAVE_SCANDIR)|g' \
 	      -e 's|@''HAVE_ALPHASORT''@|$(HAVE_ALPHASORT)|g' \
 	      -e 's|@''REPLACE_OPENDIR''@|$(REPLACE_OPENDIR)|g' \
+	      -e 's|@''REPLACE_READDIR''@|$(REPLACE_READDIR)|g' \
+	      -e 's|@''REPLACE_REWINDDIR''@|$(REPLACE_REWINDDIR)|g' \
 	      -e 's|@''REPLACE_CLOSEDIR''@|$(REPLACE_CLOSEDIR)|g' \
 	      -e 's|@''REPLACE_DIRFD''@|$(REPLACE_DIRFD)|g' \
 	      -e 's|@''REPLACE_FDOPENDIR''@|$(REPLACE_FDOPENDIR)|g' \
@@ -2116,6 +2131,8 @@ libgnu_a_SOURCES += dirfd.c
 endif
 
 endif
+EXTRA_DIST += dirent-private.h
+
 endif
 ## end   gnulib module dirfd
 
@@ -2316,6 +2333,8 @@ ifneq (,$(GL_COND_OBJ_FDOPENDIR_CONDITION))
 libgnu_a_SOURCES += fdopendir.c
 endif
 
+EXTRA_DIST += dirent-private.h
+
 endif
 ## end   gnulib module fdopendir
 
@@ -4051,6 +4070,7 @@ stdlib.h: stdlib.in.h $(top_builddir)/config.status $(CXXDEFS_H) \
 	      -e 's/@''GNULIB_GRANTPT''@/$(GL_GNULIB_GRANTPT)/g' \
 	      -e 's/@''GNULIB_MALLOC_GNU''@/$(GL_GNULIB_MALLOC_GNU)/g' \
 	      -e 's/@''GNULIB_MALLOC_POSIX''@/$(GL_GNULIB_MALLOC_POSIX)/g' \
+	      -e 's/@''GNULIB_MBSTOWCS''@/$(GL_GNULIB_MBSTOWCS)/g' \
 	      -e 's/@''GNULIB_MBTOWC''@/$(GL_GNULIB_MBTOWC)/g' \
 	      -e 's/@''GNULIB_MKDTEMP''@/$(GL_GNULIB_MKDTEMP)/g' \
 	      -e 's/@''GNULIB_MKOSTEMP''@/$(GL_GNULIB_MKOSTEMP)/g' \
@@ -4096,6 +4116,7 @@ stdlib.h: stdlib.in.h $(top_builddir)/config.status $(CXXDEFS_H) \
 	      -e 's|@''HAVE_DECL_FCVT''@|$(HAVE_DECL_FCVT)|g' \
 	      -e 's|@''HAVE_DECL_GCVT''@|$(HAVE_DECL_GCVT)|g' \
 	      -e 's|@''HAVE_DECL_GETLOADAVG''@|$(HAVE_DECL_GETLOADAVG)|g' \
+	      -e 's|@''HAVE_DECL_PROGRAM_INVOCATION_NAME''@|$(HAVE_DECL_PROGRAM_INVOCATION_NAME)|g' \
 	      -e 's|@''HAVE_GETPROGNAME''@|$(HAVE_GETPROGNAME)|g' \
 	      -e 's|@''HAVE_GETSUBOPT''@|$(HAVE_GETSUBOPT)|g' \
 	      -e 's|@''HAVE_GRANTPT''@|$(HAVE_GRANTPT)|g' \
@@ -4144,6 +4165,8 @@ stdlib.h: stdlib.in.h $(top_builddir)/config.status $(CXXDEFS_H) \
 	      -e 's|@''REPLACE_INITSTATE''@|$(REPLACE_INITSTATE)|g' \
 	      -e 's|@''REPLACE_MALLOC_FOR_MALLOC_GNU''@|$(REPLACE_MALLOC_FOR_MALLOC_GNU)|g' \
 	      -e 's|@''REPLACE_MALLOC_FOR_MALLOC_POSIX''@|$(REPLACE_MALLOC_FOR_MALLOC_POSIX)|g' \
+	      -e 's|@''REPLACE_MB_CUR_MAX''@|$(REPLACE_MB_CUR_MAX)|g' \
+	      -e 's|@''REPLACE_MBSTOWCS''@|$(REPLACE_MBSTOWCS)|g' \
 	      -e 's|@''REPLACE_MBTOWC''@|$(REPLACE_MBTOWC)|g' \
 	      -e 's|@''REPLACE_MKOSTEMP''@|$(REPLACE_MKOSTEMP)|g' \
 	      -e 's|@''REPLACE_MKOSTEMPS''@|$(REPLACE_MKOSTEMPS)|g' \
diff --git a/lib/inttypes.in.h b/lib/inttypes.in.h
index 5b7ef12dc7e..22643876ab3 100644
--- a/lib/inttypes.in.h
+++ b/lib/inttypes.in.h
@@ -46,6 +46,11 @@
 #if ! defined INTTYPES_H && ! defined _GL_JUST_INCLUDE_SYSTEM_INTTYPES_H
 #define INTTYPES_H
 
+/* This file uses GNULIB_POSIXCHECK, HAVE_RAW_DECL_*.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 /* Include <stdint.h> or the gnulib replacement.
    But avoid namespace pollution on glibc systems.  */
 #ifndef __GLIBC__
diff --git a/lib/limits.in.h b/lib/limits.in.h
index a01b4c6a280..45d46fd6897 100644
--- a/lib/limits.in.h
+++ b/lib/limits.in.h
@@ -99,6 +99,11 @@
 # endif
 #endif
 
+/* Assume no multibyte character is longer than 16 bytes.  */
+#ifndef MB_LEN_MAX
+# define MB_LEN_MAX 16
+#endif
+
 /* Macros specified by C23 and by ISO/IEC TS 18661-1:2014.  */
 
 #if (! defined ULLONG_WIDTH                                             \
diff --git a/lib/malloc/dynarray_emplace_enlarge.c b/lib/malloc/dynarray_emplace_enlarge.c
index 7da539316c1..65aabb1e4a5 100644
--- a/lib/malloc/dynarray_emplace_enlarge.c
+++ b/lib/malloc/dynarray_emplace_enlarge.c
@@ -22,7 +22,7 @@
 
 #include <dynarray.h>
 #include <errno.h>
-#include <intprops.h>
+#include <stdckdint.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -56,7 +56,7 @@ __libc_dynarray_emplace_enlarge (struct dynarray_header *list,
     }
 
   size_t new_size;
-  if (INT_MULTIPLY_WRAPV (new_allocated, element_size, &new_size))
+  if (ckd_mul (&new_size, new_allocated, element_size))
     return false;
   void *new_array;
   if (list->array == scratch)
diff --git a/lib/malloc/dynarray_resize.c b/lib/malloc/dynarray_resize.c
index 7ecd4de63b9..014f98c330e 100644
--- a/lib/malloc/dynarray_resize.c
+++ b/lib/malloc/dynarray_resize.c
@@ -22,7 +22,7 @@
 
 #include <dynarray.h>
 #include <errno.h>
-#include <intprops.h>
+#include <stdckdint.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -42,7 +42,7 @@ __libc_dynarray_resize (struct dynarray_header *list, size_t size,
      over-allocation here.  */
 
   size_t new_size_bytes;
-  if (INT_MULTIPLY_WRAPV (size, element_size, &new_size_bytes))
+  if (ckd_mul (&new_size_bytes, size, element_size))
     {
       /* Overflow.  */
       __set_errno (ENOMEM);
diff --git a/lib/md5.h b/lib/md5.h
index f34e7cb8dfa..92dc6038988 100644
--- a/lib/md5.h
+++ b/lib/md5.h
@@ -20,6 +20,11 @@
 #ifndef _MD5_H
 #define _MD5_H 1
 
+/* This file uses HAVE_OPENSSL_MD5.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #include <stdio.h>
 #include <stdint.h>
 
diff --git a/lib/minmax.h b/lib/minmax.h
index 1fbfc6616cf..0ac40198e24 100644
--- a/lib/minmax.h
+++ b/lib/minmax.h
@@ -23,6 +23,11 @@
    MIN, MAX macro redefinitions on some systems; the workaround is to
    #include this file as the last one among the #include list.  */
 
+/* This file uses HAVE_MINMAX_IN_LIMITS_H, HAVE_MINMAX_IN_SYS_PARAM_H.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 /* Before we define the following symbols we get the <limits.h> file
    since otherwise we get redefinitions on some systems if <limits.h> is
    included after this file.  Likewise for <sys/param.h>.
diff --git a/lib/mktime.c b/lib/mktime.c
index 94a4320e6ca..8e80bcdbd16 100644
--- a/lib/mktime.c
+++ b/lib/mktime.c
@@ -46,6 +46,7 @@
 #include <errno.h>
 #include <limits.h>
 #include <stdbool.h>
+#include <stdckdint.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -379,7 +380,7 @@ __mktime_internal (struct tm *tp,
   /* Invert CONVERT by probing.  First assume the same offset as last
      time.  */
 
-  INT_SUBTRACT_WRAPV (0, off, &negative_offset_guess);
+  ckd_sub (&negative_offset_guess, 0, off);
   long_int t0 = ydhms_diff (year, yday, hour, min, sec,
 			    EPOCH_YEAR - TM_YEAR_BASE, 0, 0, 0,
 			    negative_offset_guess);
@@ -465,7 +466,7 @@ __mktime_internal (struct tm *tp,
 	for (direction = -1; direction <= 1; direction += 2)
 	  {
 	    long_int ot;
-	    if (! INT_ADD_WRAPV (t, delta * direction, &ot))
+	    if (! ckd_add (&ot, t, delta * direction))
 	      {
 		struct tm otm;
 		if (! ranged_convert (convert, &ot, &otm))
@@ -503,8 +504,8 @@ __mktime_internal (struct tm *tp,
   /* Set *OFFSET to the low-order bits of T - T0 - NEGATIVE_OFFSET_GUESS.
      This is just a heuristic to speed up the next mktime call, and
      correctness is unaffected if integer overflow occurs here.  */
-  INT_SUBTRACT_WRAPV (t, t0, offset);
-  INT_SUBTRACT_WRAPV (*offset, negative_offset_guess, offset);
+  ckd_sub (offset, t, t0);
+  ckd_sub (offset, *offset, negative_offset_guess);
 
   if (LEAP_SECONDS_POSSIBLE && sec_requested != tm.tm_sec)
     {
@@ -513,7 +514,7 @@ __mktime_internal (struct tm *tp,
       long_int sec_adjustment = sec == 0 && tm.tm_sec == 60;
       sec_adjustment -= sec;
       sec_adjustment += sec_requested;
-      if (INT_ADD_WRAPV (t, sec_adjustment, &t)
+      if (ckd_add (&t, t, sec_adjustment)
 	  || ! (mktime_min <= t && t <= mktime_max))
 	{
 	  __set_errno (EOVERFLOW);
diff --git a/lib/openat.h b/lib/openat.h
index 37d8eedbee4..97f066d10f8 100644
--- a/lib/openat.h
+++ b/lib/openat.h
@@ -19,15 +19,18 @@
 #ifndef _GL_HEADER_OPENAT
 #define _GL_HEADER_OPENAT
 
+/* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE, _Noreturn,
+   _GL_ATTRIBUTE_DEPRECATED, HAVE_OPENAT.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #include <fcntl.h>
 
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
-#ifndef _GL_INLINE_HEADER_BEGIN
- #error "Please include config.h first."
-#endif
 _GL_INLINE_HEADER_BEGIN
 
 #if !HAVE_OPENAT
diff --git a/lib/pathmax.h b/lib/pathmax.h
index 0dd8f3bc5ce..6930283b82a 100644
--- a/lib/pathmax.h
+++ b/lib/pathmax.h
@@ -39,6 +39,11 @@
          #endif
  */
 
+/* This file uses HAVE_SYS_PARAM_H.  */
+# if !_GL_CONFIG_H_INCLUDED
+#  error "Please include config.h first."
+# endif
+
 # include <unistd.h>
 
 # include <limits.h>
diff --git a/lib/pselect.c b/lib/pselect.c
index f5d21e1048a..52d38378783 100644
--- a/lib/pselect.c
+++ b/lib/pselect.c
@@ -45,6 +45,12 @@ pselect (int nfds, fd_set *restrict rfds,
   sigset_t origmask;
   struct timeval tv, *tvp;
 
+  if (nfds < 0 || nfds > FD_SETSIZE)
+    {
+      errno = EINVAL;
+      return -1;
+    }
+
   if (timeout)
     {
       if (! (0 <= timeout->tv_nsec && timeout->tv_nsec < 1000000000))
diff --git a/lib/regex_internal.h b/lib/regex_internal.h
index 149ec2e868a..0270091df70 100644
--- a/lib/regex_internal.h
+++ b/lib/regex_internal.h
@@ -29,6 +29,7 @@
 #include <locale.h>
 #include <wchar.h>
 #include <wctype.h>
+#include <stdckdint.h>
 #include <stdint.h>
 
 #ifndef _LIBC
@@ -822,7 +823,7 @@ re_string_elem_size_at (const re_string_t *pstr, Idx idx)
 }
 
 #ifdef _LIBC
-# if __GNUC__ >= 7
+# if __glibc_has_attribute (__fallthrough__)
 #  define FALLTHROUGH __attribute__ ((__fallthrough__))
 # else
 #  define FALLTHROUGH ((void) 0)
diff --git a/lib/regexec.c b/lib/regexec.c
index 13e0349e727..f05f38ae0e0 100644
--- a/lib/regexec.c
+++ b/lib/regexec.c
@@ -324,7 +324,7 @@ re_search_2_stub (struct re_pattern_buffer *bufp, const char *string1,
   char *s = NULL;
 
   if (__glibc_unlikely ((length1 < 0 || length2 < 0 || stop < 0
-			 || INT_ADD_WRAPV (length1, length2, &len))))
+			 || ckd_add (&len, length1, length2))))
     return -2;
 
   /* Concatenate the strings.  */
diff --git a/lib/sha1.h b/lib/sha1.h
index 5a58b567ceb..854213a9211 100644
--- a/lib/sha1.h
+++ b/lib/sha1.h
@@ -19,6 +19,11 @@
 #ifndef SHA1_H
 # define SHA1_H 1
 
+/* This file uses HAVE_OPENSSL_SHA1.  */
+# if !_GL_CONFIG_H_INCLUDED
+#  error "Please include config.h first."
+# endif
+
 # include <stdio.h>
 # include <stdint.h>
 
diff --git a/lib/sha256.h b/lib/sha256.h
index 2879477e89c..938b1067062 100644
--- a/lib/sha256.h
+++ b/lib/sha256.h
@@ -18,6 +18,11 @@
 #ifndef SHA256_H
 # define SHA256_H 1
 
+/* This file uses HAVE_OPENSSL_SHA256.  */
+# if !_GL_CONFIG_H_INCLUDED
+#  error "Please include config.h first."
+# endif
+
 # include <stdio.h>
 # include <stdint.h>
 
diff --git a/lib/sha512.h b/lib/sha512.h
index e3a98a2644c..f3465bc8a68 100644
--- a/lib/sha512.h
+++ b/lib/sha512.h
@@ -18,6 +18,11 @@
 #ifndef SHA512_H
 # define SHA512_H 1
 
+/* This file uses HAVE_OPENSSL_SHA512.  */
+# if !_GL_CONFIG_H_INCLUDED
+#  error "Please include config.h first."
+# endif
+
 # include <stdio.h>
 # include "u64.h"
 
diff --git a/lib/signal.in.h b/lib/signal.in.h
index fea12e6572d..418d59c582d 100644
--- a/lib/signal.in.h
+++ b/lib/signal.in.h
@@ -55,6 +55,11 @@
 #ifndef _@GUARD_PREFIX@_SIGNAL_H
 #define _@GUARD_PREFIX@_SIGNAL_H
 
+/* This file uses GNULIB_POSIXCHECK, HAVE_RAW_DECL_*.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 /* For testing the OpenBSD version.  */
 #if (@GNULIB_PTHREAD_SIGMASK@ || defined GNULIB_POSIXCHECK) \
     && defined __OpenBSD__
diff --git a/lib/stat-time.h b/lib/stat-time.h
index 92aa1e64e20..5b2702356ee 100644
--- a/lib/stat-time.h
+++ b/lib/stat-time.h
@@ -20,15 +20,18 @@
 #ifndef STAT_TIME_H
 #define STAT_TIME_H 1
 
+/* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE, _GL_UNUSED,
+   _GL_ATTRIBUTE_PURE, HAVE_STRUCT_STAT_*.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #include <errno.h>
 #include <stdckdint.h>
 #include <stddef.h>
 #include <sys/stat.h>
 #include <time.h>
 
-#ifndef _GL_INLINE_HEADER_BEGIN
- #error "Please include config.h first."
-#endif
 _GL_INLINE_HEADER_BEGIN
 #ifndef _GL_STAT_TIME_INLINE
 # define _GL_STAT_TIME_INLINE _GL_INLINE
diff --git a/lib/stddef.in.h b/lib/stddef.in.h
index 6eadcc3d5a4..431e819b8bf 100644
--- a/lib/stddef.in.h
+++ b/lib/stddef.in.h
@@ -18,7 +18,7 @@
 /* Written by Eric Blake.  */
 
 /*
- * POSIX 2008 <stddef.h> for platforms that have issues.
+ * POSIX 2008 and ISO C 23 <stddef.h> for platforms that have issues.
  * <https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stddef.h.html>
  */
 
@@ -37,9 +37,9 @@
    remember if special invocation has ever been used to obtain wint_t,
    in which case we need to clean up NULL yet again.  */
 
-# if !(defined _@GUARD_PREFIX@_STDDEF_H && defined _GL_STDDEF_WINT_T)
+# if !(defined _@GUARD_PREFIX@_STDDEF_H && defined _@GUARD_PREFIX@_STDDEF_WINT_T)
 #  ifdef __need_wint_t
-#   define _GL_STDDEF_WINT_T
+#   define _@GUARD_PREFIX@_STDDEF_WINT_T
 #  endif
 #  @INCLUDE_NEXT@ @NEXT_STDDEF_H@
    /* On TinyCC, make sure that the macros that indicate the special invocation
@@ -69,6 +69,7 @@ typedef long rpl_max_align_t;
 typedef long max_align_t;
 #     define _MAX_ALIGN_T
 #    endif
+#    define __CLANG_MAX_ALIGN_T_DEFINED
 #    define GNULIB_defined_max_align_t 1
 #   endif
 #  endif
@@ -79,7 +80,7 @@ typedef long max_align_t;
 
 /* On NetBSD 5.0, the definition of NULL lacks proper parentheses.  */
 #  if (@REPLACE_NULL@ \
-       && (!defined _@GUARD_PREFIX@_STDDEF_H || defined _GL_STDDEF_WINT_T))
+       && (!defined _@GUARD_PREFIX@_STDDEF_H || defined _@GUARD_PREFIX@_STDDEF_WINT_T))
 #   undef NULL
 #   ifdef __cplusplus
    /* ISO C++ says that the macro NULL must expand to an integer constant
@@ -100,6 +101,11 @@ typedef long max_align_t;
 #  ifndef _@GUARD_PREFIX@_STDDEF_H
 #   define _@GUARD_PREFIX@_STDDEF_H
 
+/* This file uses _Noreturn.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 /* Some platforms lack wchar_t.  */
 #if !@HAVE_WCHAR_T@
 # define wchar_t int
@@ -137,11 +143,49 @@ typedef union
   long int __i _GL_STDDEF_ALIGNAS (long int);
 } rpl_max_align_t;
 #   define max_align_t rpl_max_align_t
+#   define __CLANG_MAX_ALIGN_T_DEFINED
 #   define GNULIB_defined_max_align_t 1
 #  endif
 # endif
 #endif
 
+/* ISO C 23 § 7.21.1 The unreachable macro  */
+#ifndef unreachable
+
+/* Code borrowed from verify.h.  */
+# ifndef _GL_HAS_BUILTIN_UNREACHABLE
+#  if defined __clang_major__ && __clang_major__ < 5
+#   define _GL_HAS_BUILTIN_UNREACHABLE 0
+#  elif 4 < __GNUC__ + (5 <= __GNUC_MINOR__)
+#   define _GL_HAS_BUILTIN_UNREACHABLE 1
+#  elif defined __has_builtin
+#   define _GL_HAS_BUILTIN_UNREACHABLE __has_builtin (__builtin_unreachable)
+#  else
+#   define _GL_HAS_BUILTIN_UNREACHABLE 0
+#  endif
+# endif
+
+# if _GL_HAS_BUILTIN_UNREACHABLE
+#  define unreachable() __builtin_unreachable ()
+# elif 1200 <= _MSC_VER
+#  define unreachable() __assume (0)
+# else
+/* Declare abort(), without including <stdlib.h>.  */
+extern
+#  if defined __cplusplus
+"C"
+#  endif
+_Noreturn
+void abort (void)
+#  if defined __cplusplus && (__GLIBC__ >= 2)
+throw ()
+#  endif
+;
+#  define unreachable() abort ()
+# endif
+
+#endif
+
 #  endif /* _@GUARD_PREFIX@_STDDEF_H */
 # endif /* _@GUARD_PREFIX@_STDDEF_H */
 #endif /* __need_XXX */
diff --git a/lib/stdio.in.h b/lib/stdio.in.h
index 098f841738c..6be12c0525d 100644
--- a/lib/stdio.in.h
+++ b/lib/stdio.in.h
@@ -57,6 +57,12 @@
 #ifndef _@GUARD_PREFIX@_STDIO_H
 #define _@GUARD_PREFIX@_STDIO_H
 
+/* This file uses _GL_ATTRIBUTE_DEALLOC, _GL_ATTRIBUTE_FORMAT,
+   _GL_ATTRIBUTE_MALLOC, GNULIB_POSIXCHECK, HAVE_RAW_DECL_*.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 /* Get va_list.  Needed on many systems, including glibc 2.8.  */
 #include <stdarg.h>
 
@@ -127,6 +133,16 @@
 # endif
 #endif
 
+/* _GL_ATTRIBUTE_MALLOC declares that the function returns a pointer to freshly
+   allocated memory.  */
+#ifndef _GL_ATTRIBUTE_MALLOC
+# if __GNUC__ >= 3 || defined __clang__
+#  define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
+# else
+#  define _GL_ATTRIBUTE_MALLOC
+# endif
+#endif
+
 /* An __attribute__ __format__ specifier for a function that takes a format
    string and arguments, where the format string directives are the ones
    standardized by ISO C99 and POSIX.
@@ -204,6 +220,36 @@
 # undef putc_unlocked
 #endif
 
+
+/* Maximum number of characters produced by printing a NaN value.  */
+#ifndef _PRINTF_NAN_LEN_MAX
+# if defined __FreeBSD__ || defined __DragonFly__ \
+     || defined __NetBSD__ \
+     || (defined __APPLE__ && defined __MACH__)
+/* On BSD systems, a NaN value prints as just "nan", without a sign.  */
+#  define _PRINTF_NAN_LEN_MAX 3
+# elif (__GLIBC__ >= 2) || MUSL_LIBC || defined __OpenBSD__ || defined __sun || defined __CYGWIN__
+/* glibc, musl libc, OpenBSD, Solaris libc, and Cygwin produce "[-]nan".  */
+#  define _PRINTF_NAN_LEN_MAX 4
+# elif defined _AIX
+/* AIX produces "[-]NaNQ".  */
+#  define _PRINTF_NAN_LEN_MAX 5
+# elif defined _WIN32 && !defined __CYGWIN__
+/* On native Windows, the output can be:
+   - with MSVC ucrt: "[-]nan" or "[-]nan(ind)" or "[-]nan(snan)",
+   - with mingw: "[-]1.#IND" or "[-]1.#QNAN".  */
+#  define _PRINTF_NAN_LEN_MAX 10
+# elif defined __sgi
+/* On IRIX, the output typically is "[-]nan0xNNNNNNNN" with 8 hexadecimal
+   digits.  */
+#  define _PRINTF_NAN_LEN_MAX 14
+# else
+/* We don't know, but 32 should be a safe maximum.  */
+#  define _PRINTF_NAN_LEN_MAX 32
+# endif
+#endif
+
+
 #if @GNULIB_DPRINTF@
 # if @REPLACE_DPRINTF@
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
@@ -286,7 +332,8 @@ _GL_CXXALIASWARN (fcloseall);
 #  endif
 _GL_FUNCDECL_RPL (fdopen, FILE *,
                   (int fd, const char *mode)
-                  _GL_ARG_NONNULL ((2)) _GL_ATTRIBUTE_DEALLOC (fclose, 1));
+                  _GL_ARG_NONNULL ((2)) _GL_ATTRIBUTE_DEALLOC (fclose, 1)
+                  _GL_ATTRIBUTE_MALLOC);
 _GL_CXXALIAS_RPL (fdopen, FILE *, (int fd, const char *mode));
 # elif defined _WIN32 && !defined __CYGWIN__
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
@@ -299,7 +346,8 @@ _GL_CXXALIAS_MDA (fdopen, FILE *, (int fd, const char *mode));
 /* For -Wmismatched-dealloc: Associate fdopen with fclose or rpl_fclose.  */
 _GL_FUNCDECL_SYS (fdopen, FILE *,
                   (int fd, const char *mode)
-                  _GL_ARG_NONNULL ((2)) _GL_ATTRIBUTE_DEALLOC (fclose, 1));
+                  _GL_ARG_NONNULL ((2)) _GL_ATTRIBUTE_DEALLOC (fclose, 1)
+                  _GL_ATTRIBUTE_MALLOC);
 #  endif
 _GL_CXXALIAS_SYS (fdopen, FILE *, (int fd, const char *mode));
 # endif
@@ -309,7 +357,8 @@ _GL_CXXALIASWARN (fdopen);
 /* For -Wmismatched-dealloc: Associate fdopen with fclose or rpl_fclose.  */
 _GL_FUNCDECL_SYS (fdopen, FILE *,
                   (int fd, const char *mode)
-                  _GL_ARG_NONNULL ((2)) _GL_ATTRIBUTE_DEALLOC (fclose, 1));
+                  _GL_ARG_NONNULL ((2)) _GL_ATTRIBUTE_DEALLOC (fclose, 1)
+                  _GL_ATTRIBUTE_MALLOC);
 # endif
 # if defined GNULIB_POSIXCHECK
 #  undef fdopen
@@ -420,7 +469,8 @@ _GL_CXXALIASWARN (fileno);
 #  endif
 _GL_FUNCDECL_RPL (fopen, FILE *,
                   (const char *restrict filename, const char *restrict mode)
-                  _GL_ARG_NONNULL ((1, 2)) _GL_ATTRIBUTE_DEALLOC (fclose, 1));
+                  _GL_ARG_NONNULL ((1, 2)) _GL_ATTRIBUTE_DEALLOC (fclose, 1)
+                  _GL_ATTRIBUTE_MALLOC);
 _GL_CXXALIAS_RPL (fopen, FILE *,
                   (const char *restrict filename, const char *restrict mode));
 # else
@@ -967,6 +1017,10 @@ _GL_WARN_ON_USE (gets, "gets is a security hole - use fgets instead");
 _GL_CXXALIAS_MDA (getw, int, (FILE *restrict stream));
 # else
 #  if @HAVE_DECL_GETW@
+#   if defined __APPLE__ && defined __MACH__
+/* The presence of the declaration depends on _POSIX_C_SOURCE.  */
+_GL_FUNCDECL_SYS (getw, int, (FILE *restrict stream));
+#   endif
 _GL_CXXALIAS_SYS (getw, int, (FILE *restrict stream));
 #  endif
 # endif
@@ -1071,13 +1125,15 @@ _GL_WARN_ON_USE (perror, "perror is not always POSIX compliant - "
 #  endif
 _GL_FUNCDECL_RPL (popen, FILE *,
                   (const char *cmd, const char *mode)
-                  _GL_ARG_NONNULL ((1, 2)) _GL_ATTRIBUTE_DEALLOC (pclose, 1));
+                  _GL_ARG_NONNULL ((1, 2)) _GL_ATTRIBUTE_DEALLOC (pclose, 1)
+                  _GL_ATTRIBUTE_MALLOC);
 _GL_CXXALIAS_RPL (popen, FILE *, (const char *cmd, const char *mode));
 # else
 #  if !@HAVE_POPEN@ || __GNUC__ >= 11
 _GL_FUNCDECL_SYS (popen, FILE *,
                   (const char *cmd, const char *mode)
-                  _GL_ARG_NONNULL ((1, 2)) _GL_ATTRIBUTE_DEALLOC (pclose, 1));
+                  _GL_ARG_NONNULL ((1, 2)) _GL_ATTRIBUTE_DEALLOC (pclose, 1)
+                  _GL_ATTRIBUTE_MALLOC);
 #  endif
 _GL_CXXALIAS_SYS (popen, FILE *, (const char *cmd, const char *mode));
 # endif
@@ -1087,7 +1143,8 @@ _GL_CXXALIASWARN (popen);
 /* For -Wmismatched-dealloc: Associate popen with pclose or rpl_pclose.  */
 _GL_FUNCDECL_SYS (popen, FILE *,
                   (const char *cmd, const char *mode)
-                  _GL_ARG_NONNULL ((1, 2)) _GL_ATTRIBUTE_DEALLOC (pclose, 1));
+                  _GL_ARG_NONNULL ((1, 2)) _GL_ATTRIBUTE_DEALLOC (pclose, 1)
+                  _GL_ATTRIBUTE_MALLOC);
 # endif
 # if defined GNULIB_POSIXCHECK
 #  undef popen
@@ -1210,6 +1267,10 @@ _GL_CXXALIASWARN (puts);
 _GL_CXXALIAS_MDA (putw, int, (int w, FILE *restrict stream));
 # else
 #  if @HAVE_DECL_PUTW@
+#   if defined __APPLE__ && defined __MACH__
+/* The presence of the declaration depends on _POSIX_C_SOURCE.  */
+_GL_FUNCDECL_SYS (putw, int, (int w, FILE *restrict stream));
+#   endif
 _GL_CXXALIAS_SYS (putw, int, (int w, FILE *restrict stream));
 #  endif
 # endif
@@ -1421,13 +1482,15 @@ _GL_CXXALIASWARN (tempnam);
 #   define tmpfile rpl_tmpfile
 #  endif
 _GL_FUNCDECL_RPL (tmpfile, FILE *, (void)
-                                   _GL_ATTRIBUTE_DEALLOC (fclose, 1));
+                                   _GL_ATTRIBUTE_DEALLOC (fclose, 1)
+                                   _GL_ATTRIBUTE_MALLOC);
 _GL_CXXALIAS_RPL (tmpfile, FILE *, (void));
 # else
 #  if __GNUC__ >= 11
 /* For -Wmismatched-dealloc: Associate tmpfile with fclose or rpl_fclose.  */
 _GL_FUNCDECL_SYS (tmpfile, FILE *, (void)
-                                   _GL_ATTRIBUTE_DEALLOC (fclose, 1));
+                                   _GL_ATTRIBUTE_DEALLOC (fclose, 1)
+                                   _GL_ATTRIBUTE_MALLOC);
 #  endif
 _GL_CXXALIAS_SYS (tmpfile, FILE *, (void));
 # endif
@@ -1438,7 +1501,8 @@ _GL_CXXALIASWARN (tmpfile);
 # if @GNULIB_FCLOSE@ && __GNUC__ >= 11 && !defined tmpfile
 /* For -Wmismatched-dealloc: Associate tmpfile with fclose or rpl_fclose.  */
 _GL_FUNCDECL_SYS (tmpfile, FILE *, (void)
-                                   _GL_ATTRIBUTE_DEALLOC (fclose, 1));
+                                   _GL_ATTRIBUTE_DEALLOC (fclose, 1)
+                                   _GL_ATTRIBUTE_MALLOC);
 # endif
 # if defined GNULIB_POSIXCHECK
 #  undef tmpfile
diff --git a/lib/stdlib.in.h b/lib/stdlib.in.h
index a91f4e23d67..1479a2b2871 100644
--- a/lib/stdlib.in.h
+++ b/lib/stdlib.in.h
@@ -37,6 +37,12 @@
 #ifndef _@GUARD_PREFIX@_STDLIB_H
 #define _@GUARD_PREFIX@_STDLIB_H
 
+/* This file uses _Noreturn, _GL_ATTRIBUTE_DEALLOC, _GL_ATTRIBUTE_MALLOC,
+   _GL_ATTRIBUTE_PURE, GNULIB_POSIXCHECK, HAVE_RAW_DECL_*.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 /* NetBSD 5.0 mis-defines NULL.  */
 #include <stddef.h>
 
@@ -67,9 +73,7 @@
 #  include <random.h>
 # endif
 
-# if !@HAVE_STRUCT_RANDOM_DATA@ || @REPLACE_RANDOM_R@ || !@HAVE_RANDOM_R@
-#  include <stdint.h>
-# endif
+# include <stdint.h>
 
 # if !@HAVE_STRUCT_RANDOM_DATA@
 /* Define 'struct random_data'.
@@ -461,7 +465,7 @@ _GL_WARN_ON_USE (getloadavg, "getloadavg is not portable - "
 #   undef getprogname
 #   define getprogname rpl_getprogname
 #  endif
-#  ifdef HAVE_DECL_PROGRAM_INVOCATION_NAME
+#  if @HAVE_DECL_PROGRAM_INVOCATION_NAME@
 _GL_FUNCDECL_RPL (getprogname, const char *, (void) _GL_ATTRIBUTE_PURE);
 #  else
 _GL_FUNCDECL_RPL (getprogname, const char *, (void));
@@ -469,7 +473,7 @@ _GL_FUNCDECL_RPL (getprogname, const char *, (void));
 _GL_CXXALIAS_RPL (getprogname, const char *, (void));
 # else
 #  if !@HAVE_GETPROGNAME@
-#   ifdef HAVE_DECL_PROGRAM_INVOCATION_NAME
+#   if @HAVE_DECL_PROGRAM_INVOCATION_NAME@
 _GL_FUNCDECL_SYS (getprogname, const char *, (void) _GL_ATTRIBUTE_PURE);
 #   else
 _GL_FUNCDECL_SYS (getprogname, const char *, (void));
@@ -589,6 +593,51 @@ _GL_WARN_ON_USE (malloc, "malloc is not POSIX compliant everywhere - "
 # endif
 #endif
 
+/* Return maximum number of bytes of a multibyte character.  */
+#if @REPLACE_MB_CUR_MAX@
+# if !GNULIB_defined_MB_CUR_MAX
+static inline
+int gl_MB_CUR_MAX (void)
+{
+  /* Turn the value 3 to the value 4, as needed for the UTF-8 encoding.  */
+  return MB_CUR_MAX + (MB_CUR_MAX == 3);
+}
+#  undef MB_CUR_MAX
+#  define MB_CUR_MAX gl_MB_CUR_MAX ()
+#  define GNULIB_defined_MB_CUR_MAX 1
+# endif
+#endif
+
+/* Convert a string to a wide string.  */
+#if @GNULIB_MBSTOWCS@
+# if @REPLACE_MBSTOWCS@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef mbstowcs
+#   define mbstowcs rpl_mbstowcs
+#  endif
+_GL_FUNCDECL_RPL (mbstowcs, size_t,
+                  (wchar_t *restrict dest, const char *restrict src,
+                   size_t len)
+                  _GL_ARG_NONNULL ((2)));
+_GL_CXXALIAS_RPL (mbstowcs, size_t,
+                  (wchar_t *restrict dest, const char *restrict src,
+                   size_t len));
+# else
+_GL_CXXALIAS_SYS (mbstowcs, size_t,
+                  (wchar_t *restrict dest, const char *restrict src,
+                   size_t len));
+# endif
+# if __GLIBC__ >= 2
+_GL_CXXALIASWARN (mbstowcs);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef mbstowcs
+# if HAVE_RAW_DECL_MBSTOWCS
+_GL_WARN_ON_USE (mbstowcs, "mbstowcs is unportable - "
+                 "use gnulib module mbstowcs for portability");
+# endif
+#endif
+
 /* Convert a multibyte character to a wide character.  */
 #if @GNULIB_MBTOWC@
 # if @REPLACE_MBTOWC@
@@ -1009,7 +1058,9 @@ _GL_FUNCDECL_SYS (random, long, (void));
                                int.  */
 _GL_CXXALIAS_SYS_CAST (random, long, (void));
 # endif
+# if __GLIBC__ >= 2
 _GL_CXXALIASWARN (random);
+# endif
 #elif defined GNULIB_POSIXCHECK
 # undef random
 # if HAVE_RAW_DECL_RANDOM
@@ -1034,7 +1085,9 @@ _GL_FUNCDECL_SYS (srandom, void, (unsigned int seed));
                                        unsigned long seed.  */
 _GL_CXXALIAS_SYS_CAST (srandom, void, (unsigned int seed));
 # endif
+# if __GLIBC__ >= 2
 _GL_CXXALIASWARN (srandom);
+# endif
 #elif defined GNULIB_POSIXCHECK
 # undef srandom
 # if HAVE_RAW_DECL_SRANDOM
diff --git a/lib/string.in.h b/lib/string.in.h
index b6bf432e1f1..912d0f7a306 100644
--- a/lib/string.in.h
+++ b/lib/string.in.h
@@ -44,6 +44,12 @@
 #ifndef _@GUARD_PREFIX@_STRING_H
 #define _@GUARD_PREFIX@_STRING_H
 
+/* This file uses _GL_ATTRIBUTE_DEALLOC, _GL_ATTRIBUTE_MALLOC,
+   _GL_ATTRIBUTE_PURE, GNULIB_POSIXCHECK, HAVE_RAW_DECL_*.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 /* NetBSD 5.0 mis-defines NULL.  */
 #include <stddef.h>
 
diff --git a/lib/strtol.c b/lib/strtol.c
index d11269b2622..b93483dca49 100644
--- a/lib/strtol.c
+++ b/lib/strtol.c
@@ -288,6 +288,11 @@ INTERNAL (strtol) (const STRING_TYPE *nptr, STRING_TYPE **endptr,
           s += 2;
           base = 16;
         }
+      else if ((base == 0 || base == 2) && TOUPPER (s[1]) == L_('B'))
+        {
+          s += 2;
+          base = 2;
+        }
       else if (base == 0)
         base = 8;
     }
@@ -378,11 +383,14 @@ INTERNAL (strtol) (const STRING_TYPE *nptr, STRING_TYPE **endptr,
 noconv:
   /* We must handle a special case here: the base is 0 or 16 and the
      first two characters are '0' and 'x', but the rest are no
-     hexadecimal digits.  This is no error case.  We return 0 and
-     ENDPTR points to the 'x'.  */
+     hexadecimal digits.  Likewise when the base is 0 or 2 and the
+     first two characters are '0' and 'b', but the rest are no binary
+     digits.  This is no error case.  We return 0 and ENDPTR points to
+     the 'x' or 'b'.  */
   if (endptr != NULL)
     {
-      if (save - nptr >= 2 && TOUPPER (save[-1]) == L_('X')
+      if (save - nptr >= 2
+          && (TOUPPER (save[-1]) == L_('X') || TOUPPER (save[-1]) == L_('B'))
           && save[-2] == L_('0'))
         *endptr = (STRING_TYPE *) &save[-1];
       else
diff --git a/lib/sys_random.in.h b/lib/sys_random.in.h
index 8dca1326837..b240033bcbf 100644
--- a/lib/sys_random.in.h
+++ b/lib/sys_random.in.h
@@ -45,6 +45,11 @@
 #ifndef _@GUARD_PREFIX@_SYS_RANDOM_H
 #define _@GUARD_PREFIX@_SYS_RANDOM_H
 
+/* This file uses GNULIB_POSIXCHECK, HAVE_RAW_DECL_*.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #include <sys/types.h>
 
 /* Define the GRND_* constants.  */
diff --git a/lib/sys_select.in.h b/lib/sys_select.in.h
index 13440fa6f0a..3abfc48af09 100644
--- a/lib/sys_select.in.h
+++ b/lib/sys_select.in.h
@@ -19,6 +19,13 @@
 # endif
 @PRAGMA_COLUMNS@
 
+/* This file uses #include_next of a system file that defines time_t.
+   For the 'year2038' module to work right, <config.h> needs to have been
+   included before.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 /* On OSF/1 and Solaris 2.6, <sys/types.h> and <sys/time.h>
    both include <sys/select.h>.
    On Cygwin and OpenBSD, <sys/time.h> includes <sys/select.h>.
@@ -71,6 +78,11 @@
 
 #ifndef _@GUARD_PREFIX@_SYS_SELECT_H
 
+/* This file uses GNULIB_POSIXCHECK, HAVE_RAW_DECL_*.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 /* On many platforms, <sys/select.h> assumes prior inclusion of
    <sys/types.h>.  Also, mingw defines sigset_t there, instead of
    in <signal.h> where it belongs.  */
diff --git a/lib/sys_stat.in.h b/lib/sys_stat.in.h
index 0c2f39c12bf..ad4da17fa46 100644
--- a/lib/sys_stat.in.h
+++ b/lib/sys_stat.in.h
@@ -25,6 +25,13 @@
 #endif
 @PRAGMA_COLUMNS@
 
+/* This file uses #include_next of a system file that defines time_t.
+   For the 'year2038' module to work right, <config.h> needs to have been
+   included before.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #if defined __need_system_sys_stat_h
 /* Special invocation convention.  */
 
@@ -48,6 +55,11 @@
 #ifndef _@GUARD_PREFIX@_SYS_STAT_H
 #define _@GUARD_PREFIX@_SYS_STAT_H
 
+/* This file uses GNULIB_POSIXCHECK, HAVE_RAW_DECL_*.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 /* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
 
 /* The definition of _GL_ARG_NONNULL is copied here.  */
diff --git a/lib/sys_time.in.h b/lib/sys_time.in.h
index e833d551677..59cce1440da 100644
--- a/lib/sys_time.in.h
+++ b/lib/sys_time.in.h
@@ -24,6 +24,13 @@
 #endif
 @PRAGMA_COLUMNS@
 
+/* This file uses #include_next of a system file that defines time_t.
+   For the 'year2038' module to work right, <config.h> needs to have been
+   included before.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 /* On Cygwin and on many BSDish systems, <sys/time.h> includes itself
    recursively via <sys/select.h>.
    Simply delegate to the system's header in this case; it is a no-op.
@@ -41,6 +48,11 @@
 #ifndef _@GUARD_PREFIX@_SYS_TIME_H
 #define _@GUARD_PREFIX@_SYS_TIME_H
 
+/* This file uses GNULIB_POSIXCHECK, HAVE_RAW_DECL_*.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #if ! @HAVE_SYS_TIME_H@
 # include <time.h>
 #endif
diff --git a/lib/sys_types.in.h b/lib/sys_types.in.h
index 082a6c674de..ea77e140be9 100644
--- a/lib/sys_types.in.h
+++ b/lib/sys_types.in.h
@@ -20,6 +20,13 @@
 #endif
 @PRAGMA_COLUMNS@
 
+/* This file uses #include_next of a system file that defines time_t.
+   For the 'year2038' module to work right, <config.h> needs to have been
+   included before.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #if defined _WIN32 && !defined __CYGWIN__ \
     && (defined __need_off_t || defined __need___off64_t \
         || defined __need_ssize_t || defined __need_time_t)
diff --git a/lib/time.in.h b/lib/time.in.h
index 3f9af920e34..06428adb1d0 100644
--- a/lib/time.in.h
+++ b/lib/time.in.h
@@ -20,6 +20,13 @@
 #endif
 @PRAGMA_COLUMNS@
 
+/* This file uses #include_next of a system file that defines time_t.
+   For the 'year2038' module to work right, <config.h> needs to have been
+   included before.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 /* Don't get in the way of glibc when it includes time.h merely to
    declare a few standard symbols, rather than to declare all the
    symbols.  (However, skip this for MinGW as it treats __need_time_t
@@ -45,6 +52,12 @@
 
 # @INCLUDE_NEXT@ @NEXT_TIME_H@
 
+/* This file uses _GL_ATTRIBUTE_DEPRECATED, GNULIB_POSIXCHECK,
+   HAVE_RAW_DECL_*.  */
+# if !_GL_CONFIG_H_INCLUDED
+#  error "Please include config.h first."
+# endif
+
 /* NetBSD 5.0 mis-defines NULL.  */
 # include <stddef.h>
 
@@ -154,7 +167,9 @@ _GL_CXXALIAS_RPL (time, time_t, (time_t *__tp));
 #  else
 _GL_CXXALIAS_SYS (time, time_t, (time_t *__tp));
 #  endif
+#  if __GLIBC__ >= 2
 _GL_CXXALIASWARN (time);
+#  endif
 # endif
 
 /* Sleep for at least RQTP seconds unless interrupted,  If interrupted,
@@ -341,7 +356,9 @@ _GL_CXXALIASWARN (strptime);
 #   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 #    define ctime rpl_ctime
 #   endif
+#   ifndef __cplusplus
 _GL_ATTRIBUTE_DEPRECATED
+#   endif
 _GL_FUNCDECL_RPL (ctime, char *, (time_t const *__tp)
                                  _GL_ARG_NONNULL ((1)));
 _GL_CXXALIAS_RPL (ctime, char *, (time_t const *__tp));
diff --git a/lib/timespec.h b/lib/timespec.h
index ba78647f09a..0bdfd76ef78 100644
--- a/lib/timespec.h
+++ b/lib/timespec.h
@@ -19,11 +19,14 @@
 #if ! defined TIMESPEC_H
 #define TIMESPEC_H
 
-#include <time.h>
-
-#ifndef _GL_INLINE_HEADER_BEGIN
+/* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE, _GL_ATTRIBUTE_CONST,
+   _GL_ATTRIBUTE_PURE, _GL_CMP.  */
+#if !_GL_CONFIG_H_INCLUDED
  #error "Please include config.h first."
 #endif
+
+#include <time.h>
+
 _GL_INLINE_HEADER_BEGIN
 #ifndef _GL_TIMESPEC_INLINE
 # define _GL_TIMESPEC_INLINE _GL_INLINE
diff --git a/lib/u64.h b/lib/u64.h
index 0353ad4d9af..8a99335b6aa 100644
--- a/lib/u64.h
+++ b/lib/u64.h
@@ -17,11 +17,13 @@
 
 /* Written by Paul Eggert.  */
 
-#include <stdint.h>
-
-#ifndef _GL_INLINE_HEADER_BEGIN
+/* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE.  */
+#if !_GL_CONFIG_H_INCLUDED
  #error "Please include config.h first."
 #endif
+
+#include <stdint.h>
+
 _GL_INLINE_HEADER_BEGIN
 #ifndef _GL_U64_INLINE
 # define _GL_U64_INLINE _GL_INLINE
diff --git a/lib/unistd.in.h b/lib/unistd.in.h
index 8ba9867894e..2ae040a76b3 100644
--- a/lib/unistd.in.h
+++ b/lib/unistd.in.h
@@ -69,6 +69,12 @@
 #if !defined _@GUARD_PREFIX@_UNISTD_H && !defined _GL_INCLUDING_WINSOCK2_H
 #define _@GUARD_PREFIX@_UNISTD_H
 
+/* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE, GNULIB_POSIXCHECK,
+   HAVE_RAW_DECL_*.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 /* NetBSD 5.0 mis-defines NULL.  Also get size_t.  */
 /* But avoid namespace pollution on glibc systems.  */
 #ifndef __GLIBC__
@@ -170,9 +176,6 @@
 # include <getopt-pfx-core.h>
 #endif
 
-#ifndef _GL_INLINE_HEADER_BEGIN
- #error "Please include config.h first."
-#endif
 _GL_INLINE_HEADER_BEGIN
 #ifndef _GL_UNISTD_INLINE
 # define _GL_UNISTD_INLINE _GL_INLINE
diff --git a/lib/unlocked-io.h b/lib/unlocked-io.h
index fdef624ab9c..4830df4a747 100644
--- a/lib/unlocked-io.h
+++ b/lib/unlocked-io.h
@@ -31,6 +31,11 @@
    the *_unlocked functions directly.  On hosts that lack those
    functions, invoke the non-thread-safe versions instead.  */
 
+/* This file uses HAVE_DECL_*_UNLOCKED.  */
+# if !_GL_CONFIG_H_INCLUDED
+#  error "Please include config.h first."
+# endif
+
 # include <stdio.h>
 
 # if HAVE_DECL_CLEARERR_UNLOCKED || defined clearerr_unlocked
diff --git a/lib/utimens.h b/lib/utimens.h
index a7056981f32..4a21792a7e4 100644
--- a/lib/utimens.h
+++ b/lib/utimens.h
@@ -17,6 +17,11 @@
 
 /* Written by Paul Eggert.  */
 
+/* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #include <time.h>
 int fdutimens (int, char const *, struct timespec const [2]);
 int utimens (char const *, struct timespec const [2]);
@@ -26,9 +31,6 @@ int lutimens (char const *, struct timespec const [2]);
 # include <fcntl.h>
 # include <sys/stat.h>
 
-#ifndef _GL_INLINE_HEADER_BEGIN
- #error "Please include config.h first."
-#endif
 _GL_INLINE_HEADER_BEGIN
 #ifndef _GL_UTIMENS_INLINE
 # define _GL_UTIMENS_INLINE _GL_INLINE
diff --git a/lib/verify.h b/lib/verify.h
index f0b3fc5851b..e4af91517e6 100644
--- a/lib/verify.h
+++ b/lib/verify.h
@@ -241,10 +241,16 @@ template <int w>
 #   define _Static_assert(...) \
       _GL_VERIFY (__VA_ARGS__, "static assertion failed", -)
 #  else
-    /* Work around MSVC preprocessor incompatibility with ISO C; see
-       <https://stackoverflow.com/questions/5134523/>.  */
-#   define _Static_assert(R, ...) \
-      _GL_VERIFY ((R), "static assertion failed", -)
+#   if defined __cplusplus && _MSC_VER >= 1910
+     /* In MSVC 14.1 or newer, static_assert accepts one or two arguments,
+        but _Static_assert is not defined.  */
+#    define _Static_assert static_assert
+#   else
+     /* Work around MSVC preprocessor incompatibility with ISO C; see
+        <https://stackoverflow.com/questions/5134523/>.  */
+#    define _Static_assert(R, ...) \
+       _GL_VERIFY ((R), "static assertion failed", -)
+#   endif
 #  endif
 # endif
 /* Define static_assert if needed.  */
@@ -252,7 +258,7 @@ template <int w>
       && __STDC_VERSION__ < 202311 \
       && (!defined __cplusplus \
           || (__cpp_static_assert < 201411 \
-              && __GNUG__ < 6 && __clang_major__ < 6)))
+              && __GNUG__ < 6 && __clang_major__ < 6 && _MSC_VER < 1910)))
 #  if defined __cplusplus && _MSC_VER >= 1900 && !defined __clang__
 /* MSVC 14 in C++ mode supports the two-arguments static_assert but not
    the one-argument static_assert, and it does not support _Static_assert.
@@ -285,14 +291,16 @@ template <int w>
 # define _GL_HAS_BUILTIN_TRAP 0
 #endif
 
-#if defined __clang_major__ && __clang_major__ < 5
-# define _GL_HAS_BUILTIN_UNREACHABLE 0
-#elif 4 < __GNUC__ + (5 <= __GNUC_MINOR__)
-# define _GL_HAS_BUILTIN_UNREACHABLE 1
-#elif defined __has_builtin
-# define _GL_HAS_BUILTIN_UNREACHABLE __has_builtin (__builtin_unreachable)
-#else
-# define _GL_HAS_BUILTIN_UNREACHABLE 0
+#ifndef _GL_HAS_BUILTIN_UNREACHABLE
+# if defined __clang_major__ && __clang_major__ < 5
+#  define _GL_HAS_BUILTIN_UNREACHABLE 0
+# elif 4 < __GNUC__ + (5 <= __GNUC_MINOR__)
+#  define _GL_HAS_BUILTIN_UNREACHABLE 1
+# elif defined __has_builtin
+#  define _GL_HAS_BUILTIN_UNREACHABLE __has_builtin (__builtin_unreachable)
+# else
+#  define _GL_HAS_BUILTIN_UNREACHABLE 0
+# endif
 #endif
 
 /* Each of these macros verifies that its argument R is nonzero.  To
diff --git a/m4/acl.m4 b/m4/acl.m4
index dc9853a156d..38b1dc66212 100644
--- a/m4/acl.m4
+++ b/m4/acl.m4
@@ -1,5 +1,5 @@
 # acl.m4 - check for access control list (ACL) primitives
-# serial 27
+# serial 29
 
 # Copyright (C) 2002, 2004-2023 Free Software Foundation, Inc.
 # This file is free software; the Free Software Foundation
@@ -12,7 +12,7 @@ AC_DEFUN([gl_FUNC_ACL_ARG],
 [
   gl_need_lib_has_acl=
   AC_ARG_ENABLE([acl],
-    AS_HELP_STRING([--disable-acl], [do not support ACLs]),
+    AS_HELP_STRING([[--disable-acl]], [do not support ACLs]),
     , [enable_acl=auto])
 ])
 
@@ -177,37 +177,23 @@ AC_DEFUN([gl_ACL_GET_FILE],
   AS_IF([test "$gl_cv_func_working_acl_get_file" != no], [$1], [$2])
 ])
 
-# On GNU/Linux, testing if a file has an acl can be done with the getxattr
-# syscall which doesn't require linking against additional libraries.
+# On GNU/Linux, testing if a file has an acl can be done with the
+# listxattr and getxattr syscalls, which don't require linking
+# against additional libraries.  Assume this works if linux/attr.h
+# and listxattr are present.
 AC_DEFUN([gl_FILE_HAS_ACL],
 [
   AC_REQUIRE([gl_FUNC_ACL_ARG])
-  if test "$enable_acl" != no; then
-    AC_CACHE_CHECK([for getxattr with XATTR_NAME_POSIX_ACL macros],
-      [gl_cv_getxattr_with_posix_acls],
-      [gl_cv_getxattr_with_posix_acls=no
-       AC_LINK_IFELSE(
-         [AC_LANG_PROGRAM(
-            [[#include <sys/types.h>
-              #include <sys/xattr.h>
-              #include <linux/xattr.h>
-            ]],
-            [[ssize_t a = getxattr (".", XATTR_NAME_POSIX_ACL_ACCESS, 0, 0);
-              ssize_t b = getxattr (".", XATTR_NAME_POSIX_ACL_DEFAULT, 0, 0);
-              return a < 0 || b < 0;
-            ]])],
-         [gl_cv_getxattr_with_posix_acls=yes])])
-  fi
-  if test "$gl_cv_getxattr_with_posix_acls" = yes; then
-    FILE_HAS_ACL_LIB=
-    AC_DEFINE([GETXATTR_WITH_POSIX_ACLS], 1,
-      [Define to 1 if getxattr works with XATTR_NAME_POSIX_ACL_ACCESS
-       and XATTR_NAME_POSIX_ACL_DEFAULT.])
-  else
-    dnl Set gl_need_lib_has_acl to a nonempty value, so that any
-    dnl later gl_FUNC_ACL call will set FILE_HAS_ACL_LIB=$LIB_ACL.
-    gl_need_lib_has_acl=1
-    FILE_HAS_ACL_LIB=$LIB_ACL
-  fi
+  AC_CHECK_HEADERS_ONCE([linux/xattr.h])
+  AC_CHECK_FUNCS_ONCE([listxattr])
+  FILE_HAS_ACL_LIB=
+  AS_CASE([$enable_acl,$ac_cv_header_linux_xattr_h,$ac_cv_func_listxattr],
+    [no,*,*], [],
+    [*,yes,yes], [],
+    [*],
+      [dnl Set gl_need_lib_has_acl to a nonempty value, so that any
+       dnl later gl_FUNC_ACL call will set FILE_HAS_ACL_LIB=$LIB_ACL.
+       gl_need_lib_has_acl=1
+       FILE_HAS_ACL_LIB=$LIB_ACL])
   AC_SUBST([FILE_HAS_ACL_LIB])
 ])
diff --git a/m4/codeset.m4 b/m4/codeset.m4
new file mode 100644
index 00000000000..5804f472e9a
--- /dev/null
+++ b/m4/codeset.m4
@@ -0,0 +1,24 @@
+# codeset.m4 serial 5 (gettext-0.18.2)
+dnl Copyright (C) 2000-2002, 2006, 2008-2014, 2016, 2019-2023 Free Software
+dnl 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.
+
+AC_DEFUN([AM_LANGINFO_CODESET],
+[
+  AC_CACHE_CHECK([for nl_langinfo and CODESET], [am_cv_langinfo_codeset],
+    [AC_LINK_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[#include <langinfo.h>]],
+          [[char* cs = nl_langinfo(CODESET); return !cs;]])],
+       [am_cv_langinfo_codeset=yes],
+       [am_cv_langinfo_codeset=no])
+    ])
+  if test $am_cv_langinfo_codeset = yes; then
+    AC_DEFINE([HAVE_LANGINFO_CODESET], [1],
+      [Define if you have <langinfo.h> and nl_langinfo(CODESET).])
+  fi
+])
diff --git a/m4/dirent_h.m4 b/m4/dirent_h.m4
index 2a232a7622e..b6c189c0d9f 100644
--- a/m4/dirent_h.m4
+++ b/m4/dirent_h.m4
@@ -1,4 +1,4 @@
-# dirent_h.m4 serial 19
+# dirent_h.m4 serial 20
 dnl Copyright (C) 2008-2023 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -21,12 +21,29 @@ AC_DEFUN_ONCE([gl_DIRENT_H],
   fi
   AC_SUBST([HAVE_DIRENT_H])
 
+  gl_DIRENT_DIR
+
   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 <dirent.h>
     ]], [alphasort closedir dirfd fdopendir opendir readdir rewinddir scandir])
 ])
 
+dnl Determine whether <dirent.h> needs to override the DIR type.
+AC_DEFUN_ONCE([gl_DIRENT_DIR],
+[
+  dnl Set DIR_HAS_FD_MEMBER if dirfd() works, i.e. not always returns -1,
+  dnl or has the __KLIBC__ workaround as in lib/dirfd.c.
+  dnl We could use the findings from gl_FUNC_DIRFD and gl_PREREQ_DIRFD, but
+  dnl it's simpler since we know the affected platforms.
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  case "$host_os" in
+    mingw*) DIR_HAS_FD_MEMBER=0 ;;
+    *)      DIR_HAS_FD_MEMBER=1 ;;
+  esac
+  AC_SUBST([DIR_HAS_FD_MEMBER])
+])
+
 # gl_DIRENT_MODULE_INDICATOR([modulename])
 # sets the shell variable that indicates the presence of the given module
 # to a C preprocessor expression that will evaluate to 1.
@@ -73,6 +90,8 @@ AC_DEFUN([gl_DIRENT_H_DEFAULTS],
   HAVE_SCANDIR=1;       AC_SUBST([HAVE_SCANDIR])
   HAVE_ALPHASORT=1;     AC_SUBST([HAVE_ALPHASORT])
   REPLACE_OPENDIR=0;    AC_SUBST([REPLACE_OPENDIR])
+  REPLACE_READDIR=0;    AC_SUBST([REPLACE_READDIR])
+  REPLACE_REWINDDIR=0;  AC_SUBST([REPLACE_REWINDDIR])
   REPLACE_CLOSEDIR=0;   AC_SUBST([REPLACE_CLOSEDIR])
   REPLACE_DIRFD=0;      AC_SUBST([REPLACE_DIRFD])
   REPLACE_FDOPENDIR=0;  AC_SUBST([REPLACE_FDOPENDIR])
diff --git a/m4/dirfd.m4 b/m4/dirfd.m4
index 2135535042b..7968b1287ce 100644
--- a/m4/dirfd.m4
+++ b/m4/dirfd.m4
@@ -1,4 +1,4 @@
-# serial 26   -*- Autoconf -*-
+# serial 28   -*- Autoconf -*-
 
 dnl Find out how to get the file descriptor associated with an open DIR*.
 
@@ -12,7 +12,7 @@ dnl From Jim Meyering
 AC_DEFUN([gl_FUNC_DIRFD],
 [
   AC_REQUIRE([gl_DIRENT_H_DEFAULTS])
-  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_REQUIRE([AC_CANONICAL_HOST])
 
   dnl Persuade glibc <dirent.h> to declare dirfd().
   AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
@@ -36,15 +36,20 @@ AC_DEFUN([gl_FUNC_DIRFD],
        [gl_cv_func_dirfd_macro=yes],
        [gl_cv_func_dirfd_macro=no])])
 
-  # Use the replacement if we have no function or macro with that name,
-  # or if OS/2 kLIBC whose dirfd() does not work.
-  # Replace only if the system declares dirfd already.
-  case $ac_cv_func_dirfd,$gl_cv_func_dirfd_macro,$host_os,$ac_cv_have_decl_dirfd in
-    no,no,*,yes | *,*,os2*,yes)
+  if test $ac_cv_func_dirfd = no && test $gl_cv_func_dirfd_macro = no; then
+    HAVE_DIRFD=0
+  else
+    HAVE_DIRFD=1
+    dnl Replace dirfd() on native Windows, to support fdopendir().
+    AC_REQUIRE([gl_DIRENT_DIR])
+    if test $DIR_HAS_FD_MEMBER = 0; then
       REPLACE_DIRFD=1
-      AC_DEFINE([REPLACE_DIRFD], [1],
-        [Define to 1 if gnulib's dirfd() replacement is used.]);;
-  esac
+    fi
+    dnl OS/2 kLIBC dirfd() does not work.
+    case "$host_os" in
+      os2*) REPLACE_DIRFD=1 ;;
+    esac
+  fi
 ])
 
 dnl Prerequisites of lib/dirfd.c.
diff --git a/m4/extern-inline.m4 b/m4/extern-inline.m4
index c001b1cff7d..f9894d7fe5c 100644
--- a/m4/extern-inline.m4
+++ b/m4/extern-inline.m4
@@ -79,7 +79,8 @@ AC_DEFUN([gl_EXTERN_INLINE],
 # define _GL_EXTERN_INLINE_STDHEADER_BUG
 #endif
 #if ((__GNUC__ \
-      ? defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__ \
+      ? (defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__ \
+         && !defined __PCC__) \
       : (199901L <= __STDC_VERSION__ \
          && !defined __HP_cc \
          && !defined __PGI \
@@ -89,6 +90,7 @@ AC_DEFUN([gl_EXTERN_INLINE],
 # define _GL_EXTERN_INLINE extern inline
 # define _GL_EXTERN_INLINE_IN_USE
 #elif (2 < __GNUC__ + (7 <= __GNUC_MINOR__) && !defined __STRICT_ANSI__ \
+       && !defined __PCC__ \
        && !defined _GL_EXTERN_INLINE_STDHEADER_BUG)
 # if defined __GNUC_GNU_INLINE__ && __GNUC_GNU_INLINE__
    /* __gnu_inline__ suppresses a GCC 4.2 diagnostic.  */
diff --git a/m4/gnulib-common.m4 b/m4/gnulib-common.m4
index c84a2afd9c5..edb8572da25 100644
--- a/m4/gnulib-common.m4
+++ b/m4/gnulib-common.m4
@@ -1,4 +1,4 @@
-# gnulib-common.m4 serial 82
+# gnulib-common.m4 serial 86
 dnl Copyright (C) 2007-2023 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -15,6 +15,10 @@ AC_DEFUN([gl_COMMON], [
   AC_REQUIRE([gl_ZZGNULIB])
 ])
 AC_DEFUN([gl_COMMON_BODY], [
+  AH_VERBATIM([0witness],
+[/* Witness that <config.h> has been included.  */
+#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__
@@ -116,6 +120,20 @@ AC_DEFUN([gl_COMMON_BODY], [
 # pragma GCC diagnostic ignored "-Wpedantic"
 #endif
 
+/* 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
+   various _GL_ATTRIBUTE_* can be cumulated on the same declaration in any
+   order.  */
+#ifdef __cplusplus
+# if defined __clang__
+#  define _GL_BRACKET_BEFORE_ATTRIBUTE 1
+# endif
+#else
+# if defined __GNUC__ && !defined __clang__
+#  define _GL_BRACKET_BEFORE_ATTRIBUTE 1
+# endif
+#endif
 ]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
@@ -223,9 +241,11 @@ AC_DEFUN([gl_COMMON_BODY], [
      - typedef,
    in C++ also: namespace, class, template specialization.  */
 #ifndef _GL_ATTRIBUTE_DEPRECATED
-# ifdef __has_c_attribute
-#  if __has_c_attribute (__deprecated__)
-#   define _GL_ATTRIBUTE_DEPRECATED [[__deprecated__]]
+# ifndef _GL_BRACKET_BEFORE_ATTRIBUTE
+#  ifdef __has_c_attribute
+#   if __has_c_attribute (__deprecated__)
+#    define _GL_ATTRIBUTE_DEPRECATED [[__deprecated__]]
+#   endif
 #  endif
 # endif
 # if !defined _GL_ATTRIBUTE_DEPRECATED && _GL_HAS_ATTRIBUTE (deprecated)
@@ -355,13 +375,15 @@ AC_DEFUN([gl_COMMON_BODY], [
    __has_c_attribute (__maybe_unused__) yields true but the use of
    [[__maybe_unused__]] nevertheless produces a warning.  */
 #ifndef _GL_ATTRIBUTE_MAYBE_UNUSED
-# if defined __clang__ && defined __cplusplus
-#  if !defined __apple_build_version__ && __clang_major__ >= 10
-#   define _GL_ATTRIBUTE_MAYBE_UNUSED [[__maybe_unused__]]
-#  endif
-# elif defined __has_c_attribute
-#  if __has_c_attribute (__maybe_unused__)
-#   define _GL_ATTRIBUTE_MAYBE_UNUSED [[__maybe_unused__]]
+# ifndef _GL_BRACKET_BEFORE_ATTRIBUTE
+#  if defined __clang__ && defined __cplusplus
+#   if !defined __apple_build_version__ && __clang_major__ >= 10
+#    define _GL_ATTRIBUTE_MAYBE_UNUSED [[__maybe_unused__]]
+#   endif
+#  elif defined __has_c_attribute
+#   if __has_c_attribute (__maybe_unused__)
+#    define _GL_ATTRIBUTE_MAYBE_UNUSED [[__maybe_unused__]]
+#   endif
 #  endif
 # endif
 # ifndef _GL_ATTRIBUTE_MAYBE_UNUSED
@@ -379,18 +401,20 @@ AC_DEFUN([gl_COMMON_BODY], [
    the return value, unless the caller uses something like ignore_value.  */
 /* Applies to: function, enumeration, class.  */
 #ifndef _GL_ATTRIBUTE_NODISCARD
-# if defined __clang__ && defined __cplusplus
+# ifndef _GL_BRACKET_BEFORE_ATTRIBUTE
+#  if defined __clang__ && defined __cplusplus
   /* With clang up to 15.0.6 (at least), in C++ mode, [[__nodiscard__]] produces
      a warning.
      The 1000 below means a yet unknown threshold.  When clang++ version X
      starts supporting [[__nodiscard__]] without warning about it, you can
      replace the 1000 with X.  */
-#  if __clang_major__ >= 1000
-#   define _GL_ATTRIBUTE_NODISCARD [[__nodiscard__]]
-#  endif
-# elif defined __has_c_attribute
-#  if __has_c_attribute (__nodiscard__)
-#   define _GL_ATTRIBUTE_NODISCARD [[__nodiscard__]]
+#   if __clang_major__ >= 1000
+#    define _GL_ATTRIBUTE_NODISCARD [[__nodiscard__]]
+#   endif
+#  elif defined __has_c_attribute
+#   if __has_c_attribute (__nodiscard__)
+#    define _GL_ATTRIBUTE_NODISCARD [[__nodiscard__]]
+#   endif
 #  endif
 # endif
 # if !defined _GL_ATTRIBUTE_NODISCARD && _GL_HAS_ATTRIBUTE (warn_unused_result)
@@ -528,6 +552,18 @@ AC_DEFUN([gl_COMMON_BODY], [
 # endif
 #endif
 ])
+  AH_VERBATIM([c_linkage],
+[/* In C++, there is the concept of "language linkage", that encompasses
+    name mangling and function calling conventions.
+    The following macros start and end a block of "C" linkage.  */
+#ifdef __cplusplus
+# define _GL_BEGIN_C_LINKAGE extern "C" {
+# define _GL_END_C_LINKAGE }
+#else
+# define _GL_BEGIN_C_LINKAGE
+# define _GL_END_C_LINKAGE
+#endif
+])
   AH_VERBATIM([async_safe],
 [/* The _GL_ASYNC_SAFE marker should be attached to functions that are
    signal handlers (for signals other than SIGABRT, SIGPIPE) or can be
@@ -583,7 +619,7 @@ AC_DEFUN([gl_COMMON_BODY], [
   dnl gl_cross_guess_normal    (to be used when 'yes' is good and 'no' is bad),
   dnl gl_cross_guess_inverted  (to be used when 'no' is good and 'yes' is bad).
   AC_ARG_ENABLE([cross-guesses],
-    [AS_HELP_STRING([--enable-cross-guesses={conservative|risky}],
+    [AS_HELP_STRING([[--enable-cross-guesses={conservative|risky}]],
        [specify policy for cross-compilation guesses])],
     [if test "x$enableval" != xconservative && test "x$enableval" != xrisky; then
        AC_MSG_WARN([invalid argument supplied to --enable-cross-guesses])
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index 9586b5d6486..9f701e95211 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -193,6 +193,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module stddef:
   # Code from module stdint:
   # Code from module stdio:
+  gl_STDIO_H_EARLY
   # Code from module stdlib:
   # Code from module stpcpy:
   # Code from module stpncpy:
@@ -231,7 +232,12 @@ AC_DEFUN([gl_EARLY],
   # Code from module vla:
   # Code from module warnings:
   # Code from module xalloc-oversized:
+<<<<<<< HEAD
   # Code from module xsize:
+=======
+  # Code from module year2038:
+  AC_REQUIRE([AC_SYS_YEAR2038])
+>>>>>>> origin/master
 ])
 
 # This macro should be invoked from ./configure.ac, in the section
@@ -745,7 +751,7 @@ AC_DEFUN([gl_INIT],
   gl_gnulib_enabled_xsize=false
   func_gl_gnulib_m4code_260941c0e5dc67ec9e87d1fb321c300b ()
   {
-    if ! $gl_gnulib_enabled_260941c0e5dc67ec9e87d1fb321c300b; then
+    if $gl_gnulib_enabled_260941c0e5dc67ec9e87d1fb321c300b; then :; else
       AC_REQUIRE([AC_CANONICAL_HOST])
       gl_gnulib_enabled_260941c0e5dc67ec9e87d1fb321c300b=true
       if case $host_os in mingw*) false;; *) :;; esac; then
@@ -755,17 +761,17 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_cloexec ()
   {
-    if ! $gl_gnulib_enabled_cloexec; then
+    if $gl_gnulib_enabled_cloexec; then :; else
       gl_MODULE_INDICATOR_FOR_TESTS([cloexec])
       gl_gnulib_enabled_cloexec=true
     fi
   }
   func_gl_gnulib_m4code_dirfd ()
   {
-    if ! $gl_gnulib_enabled_dirfd; then
+    if $gl_gnulib_enabled_dirfd; then :; else
       gl_FUNC_DIRFD
       gl_CONDITIONAL([GL_COND_OBJ_DIRFD],
-                     [test $ac_cv_func_dirfd = no && test $gl_cv_func_dirfd_macro = no || test $REPLACE_DIRFD = 1])
+                     [test $HAVE_DIRFD = 0 || test $REPLACE_DIRFD = 1])
       AM_COND_IF([GL_COND_OBJ_DIRFD], [
         gl_PREREQ_DIRFD
       ])
@@ -775,13 +781,13 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_925677f0343de64b89a9f0c790b4104c ()
   {
-    if ! $gl_gnulib_enabled_925677f0343de64b89a9f0c790b4104c; then
+    if $gl_gnulib_enabled_925677f0343de64b89a9f0c790b4104c; then :; else
       gl_gnulib_enabled_925677f0343de64b89a9f0c790b4104c=true
     fi
   }
   func_gl_gnulib_m4code_euidaccess ()
   {
-    if ! $gl_gnulib_enabled_euidaccess; then
+    if $gl_gnulib_enabled_euidaccess; then :; else
       gl_FUNC_EUIDACCESS
       gl_CONDITIONAL([GL_COND_OBJ_EUIDACCESS], [test $HAVE_EUIDACCESS = 0])
       AM_COND_IF([GL_COND_OBJ_EUIDACCESS], [
@@ -818,7 +824,7 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_getdtablesize ()
   {
-    if ! $gl_gnulib_enabled_getdtablesize; then
+    if $gl_gnulib_enabled_getdtablesize; then :; else
       gl_FUNC_GETDTABLESIZE
       gl_CONDITIONAL([GL_COND_OBJ_GETDTABLESIZE],
                      [test $HAVE_GETDTABLESIZE = 0 || test $REPLACE_GETDTABLESIZE = 1])
@@ -831,7 +837,7 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_getgroups ()
   {
-    if ! $gl_gnulib_enabled_getgroups; then
+    if $gl_gnulib_enabled_getgroups; then :; else
       gl_FUNC_GETGROUPS
       gl_CONDITIONAL([GL_COND_OBJ_GETGROUPS],
                      [test $HAVE_GETGROUPS = 0 || test $REPLACE_GETGROUPS = 1])
@@ -844,7 +850,7 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_be453cec5eecf5731a274f2de7f2db36 ()
   {
-    if ! $gl_gnulib_enabled_be453cec5eecf5731a274f2de7f2db36; then
+    if $gl_gnulib_enabled_be453cec5eecf5731a274f2de7f2db36; then :; else
       AC_SUBST([LIBINTL])
       AC_SUBST([LTLIBINTL])
       gl_gnulib_enabled_be453cec5eecf5731a274f2de7f2db36=true
@@ -852,14 +858,14 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_fd38c7e463b54744b77b98aeafb4fa7c ()
   {
-    if ! $gl_gnulib_enabled_fd38c7e463b54744b77b98aeafb4fa7c; then
+    if $gl_gnulib_enabled_fd38c7e463b54744b77b98aeafb4fa7c; then :; else
       AC_PROG_MKDIR_P
       gl_gnulib_enabled_fd38c7e463b54744b77b98aeafb4fa7c=true
     fi
   }
   func_gl_gnulib_m4code_8444034ea779b88768865bb60b4fb8c9 ()
   {
-    if ! $gl_gnulib_enabled_8444034ea779b88768865bb60b4fb8c9; then
+    if $gl_gnulib_enabled_8444034ea779b88768865bb60b4fb8c9; then :; else
       AC_PROG_MKDIR_P
       gl_gnulib_enabled_8444034ea779b88768865bb60b4fb8c9=true
       func_gl_gnulib_m4code_ef455225c00f5049c808c2eda3e76866
@@ -868,7 +874,7 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_a9786850e999ae65a836a6041e8e5ed1 ()
   {
-    if ! $gl_gnulib_enabled_a9786850e999ae65a836a6041e8e5ed1; then
+    if $gl_gnulib_enabled_a9786850e999ae65a836a6041e8e5ed1; then :; else
       gl_FUNC_GROUP_MEMBER
       gl_CONDITIONAL([GL_COND_OBJ_GROUP_MEMBER], [test $HAVE_GROUP_MEMBER = 0])
       AM_COND_IF([GL_COND_OBJ_GROUP_MEMBER], [
@@ -897,7 +903,7 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_lchmod ()
   {
-    if ! $gl_gnulib_enabled_lchmod; then
+    if $gl_gnulib_enabled_lchmod; then :; else
       gl_FUNC_LCHMOD
       gl_CONDITIONAL([GL_COND_OBJ_LCHMOD], [test $HAVE_LCHMOD = 0])
       AM_COND_IF([GL_COND_OBJ_LCHMOD], [
@@ -909,7 +915,7 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_e80bf6f757095d2e5fc94dafb8f8fc8b ()
   {
-    if ! $gl_gnulib_enabled_e80bf6f757095d2e5fc94dafb8f8fc8b; then
+    if $gl_gnulib_enabled_e80bf6f757095d2e5fc94dafb8f8fc8b; then :; else
       gl_FUNC_MALLOC_GNU
       if test $REPLACE_MALLOC_FOR_MALLOC_GNU = 1; then
         AC_LIBOBJ([malloc])
@@ -924,7 +930,7 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_ef455225c00f5049c808c2eda3e76866 ()
   {
-    if ! $gl_gnulib_enabled_ef455225c00f5049c808c2eda3e76866; then
+    if $gl_gnulib_enabled_ef455225c00f5049c808c2eda3e76866; then :; else
       AC_REQUIRE([gl_FUNC_MALLOC_POSIX])
       if test $REPLACE_MALLOC_FOR_MALLOC_POSIX = 1; then
         AC_LIBOBJ([malloc])
@@ -938,7 +944,7 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_5264294aa0a5557541b53c8c741f7f31 ()
   {
-    if ! $gl_gnulib_enabled_5264294aa0a5557541b53c8c741f7f31; then
+    if $gl_gnulib_enabled_5264294aa0a5557541b53c8c741f7f31; then :; else
       gl_FUNC_MKTIME_INTERNAL
       if test $WANT_MKTIME_INTERNAL = 1; then
         AC_LIBOBJ([mktime])
@@ -949,7 +955,7 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_open ()
   {
-    if ! $gl_gnulib_enabled_open; then
+    if $gl_gnulib_enabled_open; then :; else
       gl_FUNC_OPEN
       gl_CONDITIONAL([GL_COND_OBJ_OPEN], [test $REPLACE_OPEN = 1])
       AM_COND_IF([GL_COND_OBJ_OPEN], [
@@ -964,13 +970,13 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_03e0aaad4cb89ca757653bd367a6ccb7 ()
   {
-    if ! $gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7; then
+    if $gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7; then :; else
       gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7=true
     fi
   }
   func_gl_gnulib_m4code_rawmemchr ()
   {
-    if ! $gl_gnulib_enabled_rawmemchr; then
+    if $gl_gnulib_enabled_rawmemchr; then :; else
       gl_FUNC_RAWMEMCHR
       gl_CONDITIONAL([GL_COND_OBJ_RAWMEMCHR], [test $HAVE_RAWMEMCHR = 0])
       AM_COND_IF([GL_COND_OBJ_RAWMEMCHR], [
@@ -982,7 +988,7 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_d3b2383720ee0e541357aa2aac598e2b ()
   {
-    if ! $gl_gnulib_enabled_d3b2383720ee0e541357aa2aac598e2b; then
+    if $gl_gnulib_enabled_d3b2383720ee0e541357aa2aac598e2b; then :; else
       gl_FUNC_REALLOC_GNU
       if test $REPLACE_REALLOC_FOR_REALLOC_GNU = 1; then
         AC_LIBOBJ([realloc])
@@ -1000,7 +1006,7 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_61bcaca76b3e6f9ae55d57a1c3193bc4 ()
   {
-    if ! $gl_gnulib_enabled_61bcaca76b3e6f9ae55d57a1c3193bc4; then
+    if $gl_gnulib_enabled_61bcaca76b3e6f9ae55d57a1c3193bc4; then :; else
       gl_FUNC_REALLOC_POSIX
       if test $REPLACE_REALLOC_FOR_REALLOC_POSIX = 1; then
         AC_LIBOBJ([realloc])
@@ -1017,7 +1023,7 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_6099e9737f757db36c47fa9d9f02e88c ()
   {
-    if ! $gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c; then
+    if $gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c; then :; else
       gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c=true
     fi
   }
@@ -1030,7 +1036,7 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_strtoll ()
   {
-    if ! $gl_gnulib_enabled_strtoll; then
+    if $gl_gnulib_enabled_strtoll; then :; else
       gl_FUNC_STRTOLL
       gl_CONDITIONAL([GL_COND_OBJ_STRTOLL],
                      [test $HAVE_STRTOLL = 0 || test $REPLACE_STRTOLL = 1])
@@ -1043,7 +1049,7 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_utimens ()
   {
-    if ! $gl_gnulib_enabled_utimens; then
+    if $gl_gnulib_enabled_utimens; then :; else
       gl_UTIMENS
       gl_gnulib_enabled_utimens=true
     fi
@@ -1074,7 +1080,7 @@ AC_DEFUN([gl_INIT],
   }
   func_gl_gnulib_m4code_682e609604ccaac6be382e4ee3a4eaec ()
   {
-    if ! $gl_gnulib_enabled_682e609604ccaac6be382e4ee3a4eaec; then
+    if $gl_gnulib_enabled_682e609604ccaac6be382e4ee3a4eaec; then :; else
       gl_gnulib_enabled_682e609604ccaac6be382e4ee3a4eaec=true
     fi
   }
@@ -1426,6 +1432,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/count-trailing-zeros.c
   lib/count-trailing-zeros.h
   lib/diffseq.h
+  lib/dirent-private.h
   lib/dirent.in.h
   lib/dirfd.c
   lib/dtoastr.c
@@ -1650,6 +1657,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/c-bool.m4
   m4/canonicalize.m4
   m4/clock_time.m4
+  m4/codeset.m4
   m4/copy-file-range.m4
   m4/d-type.m4
   m4/dirent_h.m4
@@ -1710,6 +1718,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/ldexpl.m4
   m4/libgmp.m4
   m4/limits-h.m4
+  m4/locale-fr.m4
   m4/lstat.m4
   m4/malloc.m4
   m4/manywarnings-c++.m4
@@ -1726,6 +1735,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/mktime.m4
   m4/mode_t.m4
   m4/multiarch.m4
+  m4/musl.m4
   m4/nanosleep.m4
   m4/nocrash.m4
   m4/nproc.m4
diff --git a/m4/largefile.m4 b/m4/largefile.m4
index 7fb81b864af..a2adb533ae6 100644
--- a/m4/largefile.m4
+++ b/m4/largefile.m4
@@ -10,7 +10,7 @@
 # It does not set _LARGEFILE_SOURCE=1 on HP-UX/ia64 32-bit, although this
 # setting of _LARGEFILE_SOURCE is needed so that <stdio.h> declares fseeko
 # and ftello in C++ mode as well.
-# Fixed in Autoconf 2.72, which has AC_SYS_YEAR2038.
+# This problem occurs in Autoconf 2.71 and earlier, which lack AC_SYS_YEAR2038.
 AC_DEFUN([gl_SET_LARGEFILE_SOURCE],
  m4_ifndef([AC_SYS_YEAR2038], [[
   AC_REQUIRE([AC_CANONICAL_HOST])
@@ -24,29 +24,9 @@ AC_DEFUN([gl_SET_LARGEFILE_SOURCE],
  ]])
 )
 
-# Work around a problem in autoconf <= 2.69:
-# AC_SYS_LARGEFILE does not configure for large inodes on Mac OS X 10.5,
-# or configures them incorrectly in some cases.
-m4_version_prereq([2.70], [], [
-
-# _AC_SYS_LARGEFILE_TEST_INCLUDES
-# -------------------------------
-m4_define([_AC_SYS_LARGEFILE_TEST_INCLUDES],
-[#include <sys/types.h>
- /* Check that off_t can represent 2**63 - 1 correctly.
-    We can't simply define LARGE_OFF_T to be 9223372036854775807,
-    since some C++ compilers masquerading as C compilers
-    incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 31 << 31) - 1 + ((off_t) 1 << 31 << 31))
-  int off_t_is_large[[(LARGE_OFF_T % 2147483629 == 721
-                       && LARGE_OFF_T % 2147483647 == 1)
-                      ? 1 : -1]];[]dnl
-])
-])# m4_version_prereq 2.70
-
-# Support AC_SYS_YEAR2038, even if Autoconf 2.71 or earlier.
-# This code is taken from Autoconf master.
-m4_ifndef([AC_SYS_YEAR2038], [
+m4_ifndef([AC_SYS_YEAR2038_RECOMMENDED], [
+# Support AC_SYS_YEAR2038_RECOMMENDED and related macros, even if
+# Autoconf 2.71 or earlier.  This code is taken from Autoconf master.
 
 # _AC_SYS_YEAR2038_TEST_CODE
 # --------------------------
@@ -78,8 +58,8 @@ m4_define([_AC_SYS_YEAR2038_OPTIONS], m4_normalize(
                                       dnl 32-bit MinGW (misconfiguration)
 ))
 
-# _AC_SYS_YEAR2038_PROBE([IF-NOT-DETECTED])
-# -----------------------------------------
+# _AC_SYS_YEAR2038_PROBE
+# ----------------------
 # Subroutine of AC_SYS_YEAR2038.  Probe for time_t that can represent
 # time points more than 2**31 - 1 seconds after the epoch (dates after
 # 2038-01-18, see above) and set the cache variable ac_cv_sys_year2038_opts
@@ -92,13 +72,10 @@ m4_define([_AC_SYS_YEAR2038_OPTIONS], m4_normalize(
 # AC_TRY_RUN.  Note also that some systems only support large time_t
 # together with large off_t.
 #
-# If support is not detected, the behavior depends on which of the
-# top-level AC_SYS_YEAR2038 macros was used (see below).
-#
 # If you change this macro you may also need to change
 # _AC_SYS_YEAR2038_OPTIONS.
 AC_DEFUN([_AC_SYS_YEAR2038_PROBE],
-[AC_CACHE_CHECK([for $CC option to enable timestamps after Jan 2038],
+[AC_CACHE_CHECK([for $CC option for timestamps after 2038],
   [ac_cv_sys_year2038_opts],
   [ac_save_CPPFLAGS="$CPPFLAGS"
   ac_opt_found=no
@@ -117,40 +94,20 @@ ac_have_year2038=yes
 AS_CASE([$ac_cv_sys_year2038_opts],
   ["none needed"], [],
   ["support not detected"],
-    [ac_have_year2038=no
-     AS_CASE([$enable_year2038],
-      [yes],
-        [# If we're not cross compiling and 'touch' works with a large
-        # timestamp, then we can presume the system supports wider time_t
-        # *somehow* and we just weren't able to detect it.  One common
-        # case that we deliberately *don't* probe for is a system that
-        # supports both 32- and 64-bit ABIs but only the 64-bit ABI offers
-        # wide time_t.  (It would be inappropriate for us to override an
-        # intentional use of -m32.)  Error out, demanding use of
-        # --disable-year2038 if this is intentional.
-        AS_IF([test $cross_compiling = no],
-          [AS_IF([TZ=UTC0 touch -t 210602070628.15 conftest.time 2>/dev/null],
-            [AS_CASE([`TZ=UTC0 LC_ALL=C ls -l conftest.time 2>/dev/null`],
-              [*'Feb  7  2106'* | *'Feb  7 17:10'*],
-              [AC_MSG_FAILURE(m4_text_wrap(
-      [this system appears to support timestamps after January 2038,
-       but no mechanism for enabling wide 'time_t' was detected.
-       Did you mean to build a 64-bit binary? (e.g. 'CC="${CC} -m64"'.)
-       To proceed with 32-bit time_t, configure with '--disable-year2038'.],
-      [], [], [55]))])])])])],
+    [ac_have_year2038=no],
 
   ["-D_TIME_BITS=64"],
     [AC_DEFINE([_TIME_BITS], [64],
       [Number of bits in time_t, on hosts where this is settable.])],
 
-  ["-D__MINGW_USE_VC2005_COMPAT=1"],
+  ["-D__MINGW_USE_VC2005_COMPAT"],
     [AC_DEFINE([__MINGW_USE_VC2005_COMPAT], [1],
       [Define to 1 on platforms where this makes time_t a 64-bit type.])],
 
   ["-U_USE_32_BIT_TIME_T"*],
     [AC_MSG_FAILURE(m4_text_wrap(
       [the 'time_t' type is currently forced to be 32-bit.
-       It will stop working after January 2038.
+       It will stop working after mid-January 2038.
        Remove _USE_32BIT_TIME_T from the compiler flags.],
       [], [], [55]))],
 
@@ -160,12 +117,11 @@ AS_CASE([$ac_cv_sys_year2038_opts],
 
 # _AC_SYS_YEAR2038_ENABLE
 # -----------------------
-# Subroutine of AC_SYS_YEAR2038 and _AC_SYS_YEAR2038_OPT_IN.
 # Depending on which of the YEAR2038 macros was used, add either an
-# --enable-year2038, or a --disable-year2038, or no option at all to
-# the configure script.  Note that this is expanded very late and
+# --enable-year2038 or a --disable-year2038 to
+# the configure script.  This is expanded very late and
 # therefore there cannot be any code in the AC_ARG_ENABLE.  The
-# default value for enable_year2038 is emitted unconditionally
+# default value for 'enable_year2038' is emitted unconditionally
 # because the generated code always looks at this variable.
 m4_define([_AC_SYS_YEAR2038_ENABLE],
 [m4_divert_text([DEFAULTS],
@@ -175,35 +131,50 @@ m4_define([_AC_SYS_YEAR2038_ENABLE],
 [AC_ARG_ENABLE([year2038],
   m4_provide_if([AC_SYS_YEAR2038],
     [AS_HELP_STRING([--disable-year2038],
-      [do not support timestamps after 2038])],
+      [don't support timestamps after 2038])],
     [AS_HELP_STRING([--enable-year2038],
       [support timestamps after 2038])]))])
 
-# _AC_SYS_YEAR2038_OPT_IN
-# -----------------------
-# If the --enable-year2038 option is given to configure, attempt to
-# detect and activate support for large time_t on 32-bit systems.
-# This macro is automatically invoked by AC_SYS_LARGEFILE when large
-# *file* support is detected.  It does not AC_REQUIRE AC_SYS_LARGEFILE
-# to avoid a dependency loop, and is therefore unsafe to expose as a
-# documented macro.
-AC_DEFUN([_AC_SYS_YEAR2038_OPT_IN],
-[m4_provide_if([_AC_SYS_YEAR2038_PROBE], [], [dnl
-  AS_IF([test "$enable_year2038" != no], [_AC_SYS_YEAR2038_PROBE])
-  AC_CONFIG_COMMANDS_PRE([_AC_SYS_YEAR2038_ENABLE])
-])])
-
 # AC_SYS_YEAR2038
 # ---------------
 # Attempt to detect and activate support for large time_t.
 # On systems where time_t is not always 64 bits, this probe can be
 # skipped by passing the --disable-year2038 option to configure.
 AC_DEFUN([AC_SYS_YEAR2038],
-[AC_REQUIRE([AC_SYS_LARGEFILE])]dnl
-[m4_provide_if([_AC_SYS_YEAR2038_PROBE], [], [dnl
-  AS_IF([test "$enable_year2038" != no], [_AC_SYS_YEAR2038_PROBE])
-  AC_CONFIG_COMMANDS_PRE([_AC_SYS_YEAR2038_ENABLE])
-])])
+[AC_REQUIRE([AC_SYS_LARGEFILE])dnl
+AS_IF([test "$enable_year2038,$ac_have_year2038,$cross_compiling" = yes,no,no],
+ [# If we're not cross compiling and 'touch' works with a large
+  # timestamp, then we can presume the system supports wider time_t
+  # *somehow* and we just weren't able to detect it.  One common
+  # case that we deliberately *don't* probe for is a system that
+  # supports both 32- and 64-bit ABIs but only the 64-bit ABI offers
+  # wide time_t.  (It would be inappropriate for us to override an
+  # intentional use of -m32.)  Error out, demanding use of
+  # --disable-year2038 if this is intentional.
+  AS_IF([TZ=UTC0 touch -t 210602070628.15 conftest.time 2>/dev/null],
+    [AS_CASE([`TZ=UTC0 LC_ALL=C ls -l conftest.time 2>/dev/null`],
+       [*'Feb  7  2106'* | *'Feb  7 17:10'*],
+       [AC_MSG_FAILURE(m4_text_wrap(
+	  [this system appears to support timestamps after mid-January 2038,
+	   but no mechanism for enabling wide 'time_t' was detected.
+	   Did you mean to build a 64-bit binary? (E.g., 'CC="${CC} -m64"'.)
+	   To proceed with 32-bit time_t, configure with '--disable-year2038'.],
+	  [], [], [55]))])])])])
+
+# AC_SYS_YEAR2038_RECOMMENDED
+# ---------------------------
+# Same as AC_SYS_YEAR2038, but recommend support for large time_t.
+# If we cannot find any way to make time_t capable of representing
+# values larger than 2**31 - 1, error out unless --disable-year2038 is given.
+AC_DEFUN([AC_SYS_YEAR2038_RECOMMENDED],
+[AC_REQUIRE([AC_SYS_YEAR2038])dnl
+AS_IF([test "$enable_year2038,$ac_have_year2038" = yes,no],
+   [AC_MSG_FAILURE(m4_text_wrap(
+      [could not enable timestamps after mid-January 2038.
+       This package recommends support for these later timestamps.
+       However, to proceed with signed 32-bit time_t even though it
+       will fail then, configure with '--disable-year2038'.],
+      [], [], [55]))])])
 
 # _AC_SYS_LARGEFILE_TEST_CODE
 # ---------------------------
@@ -219,6 +190,8 @@ m4_define([_AC_SYS_LARGEFILE_TEST_CODE],
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1]];[]dnl
 ])
+# Defined by Autoconf 2.71 and circa 2022 Gnulib unwisely depended on it.
+m4_define([_AC_SYS_LARGEFILE_TEST_INCLUDES], [_AC_SYS_LARGEFILE_TEST_CODE])
 
 # _AC_SYS_LARGEFILE_OPTIONS
 # -------------------------
@@ -228,8 +201,8 @@ m4_define([_AC_SYS_LARGEFILE_TEST_CODE],
 m4_define([_AC_SYS_LARGEFILE_OPTIONS], m4_normalize(
     ["none needed"]                   dnl Most current systems
     ["-D_FILE_OFFSET_BITS=64"]        dnl X/Open LFS spec
-    ["-D_LARGE_FILES=1"]              dnl AIX (which versions?)
-    ["-n32"]                          dnl Irix 6.2 w/ SGI compiler
+    ["-D_LARGE_FILES=1"]              dnl 32-bit AIX 4.2.1+, 32-bit z/OS
+    ["-n32"]                          dnl 32-bit IRIX 6, SGI cc (obsolete)
 ))
 
 # _AC_SYS_LARGEFILE_PROBE
@@ -259,11 +232,24 @@ AC_DEFUN([_AC_SYS_LARGEFILE_PROBE],
     test $ac_opt_found = no || break
   done
   CC="$ac_save_CC"
+  dnl Gnulib implements large file support for native Windows, based on the
+  dnl variables WINDOWS_64_BIT_OFF_T, WINDOWS_64_BIT_ST_SIZE.
+  m4_ifdef([gl_LARGEFILE], [
+    AC_REQUIRE([AC_CANONICAL_HOST])
+    if test $ac_opt_found != yes; then
+      AS_CASE([$host_os],
+        [mingw*],
+          [ac_cv_sys_largefile_opts="supported through gnulib"
+           ac_opt_found=yes]
+      )
+    fi
+  ])
   test $ac_opt_found = yes || ac_cv_sys_largefile_opts="support not detected"])
 
 ac_have_largefile=yes
 AS_CASE([$ac_cv_sys_largefile_opts],
   ["none needed"], [],
+  ["supported through gnulib"], [],
   ["support not detected"],
     [ac_have_largefile=no],
 
@@ -281,21 +267,9 @@ AS_CASE([$ac_cv_sys_largefile_opts],
   [AC_MSG_ERROR(
     [internal error: bad value for \$ac_cv_sys_largefile_opts])])
 
-_AC_SYS_YEAR2038_OPT_IN
-])
-
-# _AC_SYS_LARGEFILE_ENABLE
-# ------------------------
-# Subroutine of AC_SYS_LARGEFILE.  Note that this
-# is expanded very late and therefore there cannot be any code in the
-# AC_ARG_ENABLE.  The default value for enable_largefile is emitted
-# unconditionally because the generated shell code always looks at
-# this variable.
-m4_define([_AC_SYS_LARGEFILE_ENABLE],
-[m4_divert_text([DEFAULTS],
-  enable_largefile=yes)]dnl
-[AC_ARG_ENABLE([largefile],
-  [AS_HELP_STRING([--disable-largefile], [omit support for large files])])])
+AS_IF([test "$enable_year2038" != no],
+  [_AC_SYS_YEAR2038_PROBE])
+AC_CONFIG_COMMANDS_PRE([_AC_SYS_YEAR2038_ENABLE])])
 
 # AC_SYS_LARGEFILE
 # ----------------
@@ -306,14 +280,13 @@ m4_define([_AC_SYS_LARGEFILE_ENABLE],
 # Additionally, on Linux file systems with 64-bit inodes a file that happens
 # to have a 64-bit inode number cannot be accessed by 32-bit applications on
 # Linux x86/x86_64.  This can occur with file systems such as XFS and NFS.
-# This macro allows configuration to continue if the system doesn't support
-# large files.
 AC_DEFUN([AC_SYS_LARGEFILE],
-[m4_provide_if([_AC_SYS_LARGEFILE_PROBE], [], [dnl
-  AS_IF([test "$enable_largefile" != no], [_AC_SYS_LARGEFILE_PROBE])
-  AC_CONFIG_COMMANDS_PRE([_AC_SYS_LARGEFILE_ENABLE])
-])])
-])# m4_ifndef AC_SYS_YEAR2038
+[AC_ARG_ENABLE([largefile],
+   [AS_HELP_STRING([--disable-largefile],
+      [omit support for large files])])dnl
+AS_IF([test "$enable_largefile,$enable_year2038" != no,no],
+  [_AC_SYS_LARGEFILE_PROBE])])
+])# m4_ifndef AC_SYS_YEAR2038_RECOMMENDED
 
 # Enable large files on systems where this is implemented by Gnulib, not by the
 # system headers.
diff --git a/m4/libgmp.m4 b/m4/libgmp.m4
index 58576c4d0c5..eb20ada0fa5 100644
--- a/m4/libgmp.m4
+++ b/m4/libgmp.m4
@@ -1,4 +1,4 @@
-# libgmp.m4 serial 7
+# libgmp.m4 serial 8
 # Configure the GMP library or a replacement.
 dnl Copyright 2020-2023 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
@@ -15,7 +15,7 @@ dnl empty.
 AC_DEFUN([gl_LIBGMP],
 [
   AC_ARG_WITH([libgmp],
-    [AS_HELP_STRING([--without-libgmp],
+    [AS_HELP_STRING([[--without-libgmp]],
        [do not use the GNU Multiple Precision (GMP) library;
         this is the default on systems lacking libgmp.])])
   HAVE_LIBGMP=no
diff --git a/m4/limits-h.m4 b/m4/limits-h.m4
index 4f8ce41098a..ca0294e5500 100644
--- a/m4/limits-h.m4
+++ b/m4/limits-h.m4
@@ -24,6 +24,7 @@ AC_DEFUN_ONCE([gl_LIMITS_H],
             int ullw = ULLONG_WIDTH;
             int bw = BOOL_WIDTH;
             int bm = BOOL_MAX;
+            int mblm = MB_LEN_MAX;
           ]])],
        [gl_cv_header_limits_width=yes],
        [gl_cv_header_limits_width=no])])
diff --git a/m4/locale-fr.m4 b/m4/locale-fr.m4
new file mode 100644
index 00000000000..5e13f3945d2
--- /dev/null
+++ b/m4/locale-fr.m4
@@ -0,0 +1,253 @@
+# locale-fr.m4 serial 21
+dnl Copyright (C) 2003, 2005-2023 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 a french locale with traditional encoding.
+AC_DEFUN_ONCE([gt_LOCALE_FR],
+[
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  AC_REQUIRE([AM_LANGINFO_CODESET])
+  AC_CACHE_CHECK([for a traditional french locale], [gt_cv_locale_fr], [
+    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__
+  return 1;
+#else
+  /* 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 nonempty and not "ASCII" or "646".
+     On Mac OS X 10.3.5 (Darwin 7.5) in the fr_FR locale, nl_langinfo(CODESET)
+     is empty, and the behaviour of Tcl 8.4 in this locale is not useful.
+     On OpenBSD 4.0, when an unsupported locale is specified, setlocale()
+     succeeds but then nl_langinfo(CODESET) is "646". In this situation,
+     some unit tests fail.
+     On MirBSD 10, when an unsupported locale is specified, setlocale()
+     succeeds but then nl_langinfo(CODESET) is "UTF-8".  */
+# if HAVE_LANGINFO_CODESET
+  {
+    const char *cs = nl_langinfo (CODESET);
+    if (cs[0] == '\0' || strcmp (cs, "ASCII") == 0 || strcmp (cs, "646") == 0
+        || strcmp (cs, "UTF-8") == 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 whether in the abbreviation of the second month, the second
+     character (should be U+00E9: LATIN SMALL LETTER E WITH ACUTE) is only
+     one byte long. This excludes the UTF-8 encoding.  */
+  t.tm_year = 1975 - 1900; t.tm_mon = 2 - 1; t.tm_mday = 4;
+  if (strftime (buf, sizeof (buf), "%b", &t) < 3 || buf[2] != 'v') return 1;
+# if !defined __BIONIC__ /* Bionic libc's 'struct lconv' is just a dummy.  */
+  /* Check whether the decimal separator is a comma.
+     On NetBSD 3.0 in the fr_FR.ISO8859-1 locale, localeconv()->decimal_point
+     are nl_langinfo(RADIXCHAR) are both ".".  */
+  if (localeconv () ->decimal_point[0] != ',') return 1;
+# endif
+  return 0;
+#endif
+}
+      ]])])
+    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" as "Arabic" or "Arabic_Saudi Arabia.1256",
+        # "fr" or "fra" as "French" or "French_France.1252",
+        # "ge"(!) or "deu"(!) as "German" or "German_Germany.1252",
+        # "ja" as "Japanese" or "Japanese_Japan.932",
+        # and similar.
+        mingw*)
+          # Test for the native Windows locale name.
+          if (LC_ALL=French_France.1252 LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
+            gt_cv_locale_fr=French_France.1252
+          else
+            # None found.
+            gt_cv_locale_fr=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 usual locale name.
+          if (LC_ALL=fr_FR LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
+            gt_cv_locale_fr=fr_FR
+          else
+            # Test for the locale name with explicit encoding suffix.
+            if (LC_ALL=fr_FR.ISO-8859-1 LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
+              gt_cv_locale_fr=fr_FR.ISO-8859-1
+            else
+              # Test for the AIX, OSF/1, FreeBSD, NetBSD, OpenBSD locale name.
+              if (LC_ALL=fr_FR.ISO8859-1 LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
+                gt_cv_locale_fr=fr_FR.ISO8859-1
+              else
+                # Test for the HP-UX locale name.
+                if (LC_ALL=fr_FR.iso88591 LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
+                  gt_cv_locale_fr=fr_FR.iso88591
+                else
+                  # Test for the Solaris 7 locale name.
+                  if (LC_ALL=fr LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
+                    gt_cv_locale_fr=fr
+                  else
+                    # None found.
+                    gt_cv_locale_fr=none
+                  fi
+                fi
+              fi
+            fi
+          fi
+          ;;
+      esac
+    fi
+    rm -fr conftest*
+  ])
+  LOCALE_FR=$gt_cv_locale_fr
+  AC_SUBST([LOCALE_FR])
+])
+
+dnl Determine the name of a french locale with UTF-8 encoding.
+AC_DEFUN_ONCE([gt_LOCALE_FR_UTF8],
+[
+  AC_REQUIRE([AM_LANGINFO_CODESET])
+  AC_CACHE_CHECK([for a french Unicode locale], [gt_cv_locale_fr_utf8], [
+    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 nonempty and not "ASCII" or "646".
+     On Mac OS X 10.3.5 (Darwin 7.5) in the fr_FR locale, nl_langinfo(CODESET)
+     is empty, and the behaviour of Tcl 8.4 in this locale is not useful.
+     On OpenBSD 4.0, when an unsupported locale is specified, setlocale()
+     succeeds but then nl_langinfo(CODESET) is "646". In this situation,
+     some unit tests fail.  */
+# if HAVE_LANGINFO_CODESET
+  {
+    const char *cs = nl_langinfo (CODESET);
+    if (cs[0] == '\0' || strcmp (cs, "ASCII") == 0 || strcmp (cs, "646") == 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 whether in the abbreviation of the second month, the second
+     character (should be U+00E9: LATIN SMALL LETTER E WITH ACUTE) is
+     two bytes long, with UTF-8 encoding.  */
+  t.tm_year = 1975 - 1900; t.tm_mon = 2 - 1; t.tm_mday = 4;
+  if (strftime (buf, sizeof (buf), "%b", &t) < 4
+      || buf[1] != (char) 0xc3 || buf[2] != (char) 0xa9 || buf[3] != 'v')
+    return 1;
+#endif
+#if !defined __BIONIC__ /* Bionic libc's 'struct lconv' is just a dummy.  */
+  /* Check whether the decimal separator is a comma.
+     On NetBSD 3.0 in the fr_FR.ISO8859-1 locale, localeconv()->decimal_point
+     are nl_langinfo(RADIXCHAR) are both ".".  */
+  if (localeconv () ->decimal_point[0] != ',') return 1;
+#endif
+  return 0;
+}
+      ]])])
+    if AC_TRY_EVAL([ac_link]) && test -s conftest$ac_exeext; then
+      case "$host_os" in
+        # Handle native Windows specially, because there setlocale() interprets
+        # "ar" as "Arabic" or "Arabic_Saudi Arabia.1256",
+        # "fr" or "fra" as "French" or "French_France.1252",
+        # "ge"(!) or "deu"(!) as "German" or "German_Germany.1252",
+        # "ja" as "Japanese" or "Japanese_Japan.932",
+        # and similar.
+        mingw*)
+          # Test for the hypothetical native Windows locale name.
+          if (LC_ALL=French_France.65001 LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
+            gt_cv_locale_fr_utf8=French_France.65001
+          else
+            # None found.
+            gt_cv_locale_fr_utf8=none
+          fi
+          ;;
+        *)
+          # Setting LC_ALL is not enough. Need to set LC_TIME to empty, because
+          # otherwise on Mac OS X 10.3.5 the LC_TIME=C from the beginning of the
+          # configure script would override the LC_ALL setting. Likewise for
+          # LC_CTYPE, which is also set at the beginning of the configure script.
+          # Test for the usual locale name.
+          if (LC_ALL=fr_FR LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
+            gt_cv_locale_fr_utf8=fr_FR
+          else
+            # Test for the locale name with explicit encoding suffix.
+            if (LC_ALL=fr_FR.UTF-8 LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
+              gt_cv_locale_fr_utf8=fr_FR.UTF-8
+            else
+              # Test for the Solaris 7 locale name.
+              if (LC_ALL=fr.UTF-8 LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
+                gt_cv_locale_fr_utf8=fr.UTF-8
+              else
+                # None found.
+                gt_cv_locale_fr_utf8=none
+              fi
+            fi
+          fi
+          ;;
+      esac
+    fi
+    rm -fr conftest*
+  ])
+  LOCALE_FR_UTF8=$gt_cv_locale_fr_utf8
+  AC_SUBST([LOCALE_FR_UTF8])
+])
diff --git a/m4/manywarnings.m4 b/m4/manywarnings.m4
index 2fac86e20be..13db996516d 100644
--- a/m4/manywarnings.m4
+++ b/m4/manywarnings.m4
@@ -46,8 +46,7 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC(C)],
   dnl First, check for some issues that only occur when combining multiple
   dnl gcc warning categories.
   AC_REQUIRE([AC_PROG_CC])
-  if test -n "$GCC"; then
-
+  AS_IF([test -n "$GCC"], [
     dnl Check if -Wextra -Werror -Wno-missing-field-initializers is supported
     dnl with the current $CC $CFLAGS $CPPFLAGS.
     AC_CACHE_CHECK([whether -Wno-missing-field-initializers is supported],
@@ -61,7 +60,7 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC(C)],
        CFLAGS="$gl_save_CFLAGS"
       ])
 
-    if test "$gl_cv_cc_nomfi_supported" = yes; then
+    AS_IF([test "$gl_cv_cc_nomfi_supported" = yes], [
       dnl Now check whether -Wno-missing-field-initializers is needed
       dnl for the { 0, } construct.
       AC_CACHE_CHECK([whether -Wno-missing-field-initializers is needed],
@@ -82,7 +81,7 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC(C)],
            [gl_cv_cc_nomfi_needed=yes])
          CFLAGS="$gl_save_CFLAGS"
         ])
-    fi
+    ])
 
     dnl Next, check if -Werror -Wuninitialized is useful with the
     dnl user's choice of $CFLAGS; some versions of gcc warn that it
@@ -97,8 +96,7 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC(C)],
          [gl_cv_cc_uninitialized_supported=no])
        CFLAGS="$gl_save_CFLAGS"
       ])
-
-  fi
+  ])
 
   # List all gcc warning categories.
   # To compare this list to your installed GCC's, run this Bash command:
@@ -109,7 +107,7 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC(C)],
   #  <(LC_ALL=C gcc --help=warnings | sed -n 's/^  \(-[^ ]*\) .*/\1/p' | sort)
 
   $1=
-  for gl_manywarn_item in -fanalyzer -fno-common \
+  for gl_manywarn_item in -fanalyzer -fstrict-flex-arrays \
     -Wall \
     -Warith-conversion \
     -Wbad-function-cast \
@@ -137,6 +135,7 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC(C)],
     -Wpointer-arith \
     -Wshadow \
     -Wstack-protector \
+    -Wstrict-flex-arrays \
     -Wstrict-overflow \
     -Wstrict-prototypes \
     -Wsuggest-attribute=cold \
@@ -178,14 +177,19 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC(C)],
   gl_AS_VAR_APPEND([$1], [' -Wvla-larger-than=4031'])
 
   # These are needed for older GCC versions.
-  if test -n "$GCC"; then
-    case `($CC --version) 2>/dev/null` in
+  if test -n "$GCC" && gl_gcc_version=`($CC --version) 2>/dev/null`; then
+    case $gl_gcc_version in
       'gcc (GCC) '[[0-3]].* | \
       'gcc (GCC) '4.[[0-7]].*)
         gl_AS_VAR_APPEND([$1], [' -fdiagnostics-show-option'])
         gl_AS_VAR_APPEND([$1], [' -funit-at-a-time'])
           ;;
     esac
+    case $gl_gcc_version in
+      'gcc (GCC) '[[0-9]].*)
+        gl_AS_VAR_APPEND([$1], [' -fno-common'])
+          ;;
+    esac
   fi
 
   # Disable specific options as needed.
diff --git a/m4/musl.m4 b/m4/musl.m4
new file mode 100644
index 00000000000..e28a3fed677
--- /dev/null
+++ b/m4/musl.m4
@@ -0,0 +1,20 @@
+# musl.m4 serial 4
+dnl Copyright (C) 2019-2023 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.
+
+# Test for musl libc, despite the musl libc authors don't like it
+# <https://wiki.musl-libc.org/faq.html>
+# <https://lists.gnu.org/archive/html/bug-gnulib/2018-02/msg00079.html>.
+# From Bruno Haible.
+
+AC_DEFUN_ONCE([gl_MUSL_LIBC],
+[
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  case "$host_os" in
+    *-musl* | midipix*)
+      AC_DEFINE([MUSL_LIBC], [1], [Define to 1 on musl libc.])
+      ;;
+  esac
+])
diff --git a/m4/regex.m4 b/m4/regex.m4
index c89a1432a7b..7acadc48343 100644
--- a/m4/regex.m4
+++ b/m4/regex.m4
@@ -1,4 +1,4 @@
-# serial 73
+# serial 74
 
 # Copyright (C) 1996-2001, 2003-2023 Free Software Foundation, Inc.
 #
@@ -15,7 +15,7 @@ AC_DEFUN([gl_REGEX],
 [
   AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   AC_ARG_WITH([included-regex],
-    [AS_HELP_STRING([--without-included-regex],
+    [AS_HELP_STRING([[--without-included-regex]],
                     [don't compile regex; this is the default on systems
                      with recent-enough versions of the GNU C Library
                      (use with caution on other systems).])])
diff --git a/m4/stdalign.m4 b/m4/stdalign.m4
index f49cf8ec162..1a236d66d2f 100644
--- a/m4/stdalign.m4
+++ b/m4/stdalign.m4
@@ -151,22 +151,22 @@ AC_DEFUN([gl_ALIGNASOF],
      - alignas (TYPE) is equivalent to alignas (alignof (TYPE)).
 
    */
-# if !HAVE_STDALIGN_H
-#  if !defined __STDC_VERSION__ || __STDC_VERSION__ < 201112
-#   if defined __cplusplus && (201103 <= __cplusplus || defined _MSC_VER)
-#    define _Alignas(a) alignas (a)
-#   elif (!defined __attribute__ \
-          && ((defined __APPLE__ && defined __MACH__ \
-               ? 4 < __GNUC__ + (1 <= __GNUC_MINOR__) \
-               : __GNUC__ && !defined __ibmxl__) \
-              || (4 <= __clang_major__) \
-              || (__ia64 && (61200 <= __HP_cc || 61200 <= __HP_aCC)) \
-              || __ICC || 0x590 <= __SUNPRO_C || 0x0600 <= __xlC__))
-#    define _Alignas(a) __attribute__ ((__aligned__ (a)))
-#   elif 1300 <= _MSC_VER
-#    define _Alignas(a) __declspec (align (a))
-#   endif
+# if !defined __STDC_VERSION__ || __STDC_VERSION__ < 201112
+#  if defined __cplusplus && (201103 <= __cplusplus || defined _MSC_VER)
+#   define _Alignas(a) alignas (a)
+#  elif (!defined __attribute__ \
+         && ((defined __APPLE__ && defined __MACH__ \
+              ? 4 < __GNUC__ + (1 <= __GNUC_MINOR__) \
+              : __GNUC__ && !defined __ibmxl__) \
+             || (4 <= __clang_major__) \
+             || (__ia64 && (61200 <= __HP_cc || 61200 <= __HP_aCC)) \
+             || __ICC || 0x590 <= __SUNPRO_C || 0x0600 <= __xlC__))
+#   define _Alignas(a) __attribute__ ((__aligned__ (a)))
+#  elif 1300 <= _MSC_VER
+#   define _Alignas(a) __declspec (align (a))
 #  endif
+# endif
+# if !HAVE_STDALIGN_H
 #  if ((defined _Alignas \
         && !(defined __cplusplus \
              && (201103 <= __cplusplus || defined _MSC_VER))) \
diff --git a/m4/stddef_h.m4 b/m4/stddef_h.m4
index a2322ebb7ee..aa012219fcd 100644
--- a/m4/stddef_h.m4
+++ b/m4/stddef_h.m4
@@ -1,4 +1,4 @@
-# stddef_h.m4 serial 13
+# stddef_h.m4 serial 14
 dnl Copyright (C) 2009-2023 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -68,6 +68,21 @@ AC_DEFUN_ONCE([gl_STDDEF_H],
     GL_GENERATE_STDDEF_H=true
   fi
 
+  AC_CACHE_CHECK([for unreachable],
+    [gl_cv_func_unreachable],
+    [AC_LINK_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[#include <stddef.h>
+          ]],
+          [[unreachable ();
+          ]])],
+       [gl_cv_func_unreachable=yes],
+       [gl_cv_func_unreachable=no])
+    ])
+  if test $gl_cv_func_unreachable = no; then
+    GL_GENERATE_STDDEF_H=true
+  fi
+
   if $GL_GENERATE_STDDEF_H; then
     gl_NEXT_HEADERS([stddef.h])
   fi
diff --git a/m4/stdio_h.m4 b/m4/stdio_h.m4
index 07569961f8b..dbfa0d5d61b 100644
--- a/m4/stdio_h.m4
+++ b/m4/stdio_h.m4
@@ -1,12 +1,22 @@
-# stdio_h.m4 serial 61
+# stdio_h.m4 serial 63
 dnl Copyright (C) 2007-2023 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.
 
-AC_DEFUN_ONCE([gl_STDIO_H],
+AC_DEFUN([gl_STDIO_H_EARLY],
 [
-  AC_REQUIRE([gl_STDIO_H_DEFAULTS])
+  dnl Defining __USE_MINGW_ANSI_STDIO to 1 must be done early, because
+  dnl the results of several configure tests depend on it: The tests
+  dnl   - checking whether snprintf returns a byte count as in C99...
+  dnl   - checking whether snprintf truncates the result as in C99...
+  dnl   - checking whether printf supports the 'F' directive...
+  dnl   - checking whether printf supports the grouping flag...
+  dnl   - checking whether printf supports the zero flag correctly...
+  dnl   - checking whether printf supports infinite 'double' arguments...
+  dnl   - checking whether printf supports large precisions...
+  dnl report 'yes' if __USE_MINGW_ANSI_STDIO is 1 but 'no' if
+  dnl __USE_MINGW_ANSI_STDIO is not set.
   AH_VERBATIM([MINGW_ANSI_STDIO],
 [/* Use GNU style printf and scanf.  */
 #ifndef __USE_MINGW_ANSI_STDIO
@@ -14,6 +24,11 @@ AC_DEFUN_ONCE([gl_STDIO_H],
 #endif
 ])
   AC_DEFINE([__USE_MINGW_ANSI_STDIO])
+])
+
+AC_DEFUN_ONCE([gl_STDIO_H],
+[
+  AC_REQUIRE([gl_STDIO_H_DEFAULTS])
   gl_NEXT_HEADERS([stdio.h])
 
   dnl Determine whether __USE_MINGW_ANSI_STDIO makes printf and
@@ -40,6 +55,9 @@ AC_DEFUN_ONCE([gl_STDIO_H],
        attribute "__gnu_printf__" instead of "__printf__"])
   fi
 
+  dnl For defining _PRINTF_NAN_LEN_MAX.
+  gl_MUSL_LIBC
+
   dnl This ifdef is an optimization, to avoid performing a configure check whose
   dnl result is not used. But it does not make the test of
   dnl GNULIB_STDIO_H_NONBLOCKING or GNULIB_NONBLOCKING redundant.
diff --git a/m4/stdlib_h.m4 b/m4/stdlib_h.m4
index 249ef657224..f47c1eb37b3 100644
--- a/m4/stdlib_h.m4
+++ b/m4/stdlib_h.m4
@@ -1,4 +1,4 @@
-# stdlib_h.m4 serial 71
+# stdlib_h.m4 serial 75
 dnl Copyright (C) 2007-2023 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -24,14 +24,57 @@ AC_DEFUN_ONCE([gl_STDLIB_H],
 #endif
     ]], [_Exit aligned_alloc atoll canonicalize_file_name free
     getloadavg getprogname getsubopt grantpt
-    initstate initstate_r mbtowc mkdtemp mkostemp mkostemps mkstemp mkstemps
-    posix_memalign posix_openpt ptsname ptsname_r qsort_r
+    initstate initstate_r mbstowcs mbtowc mkdtemp mkostemp mkostemps mkstemp
+    mkstemps posix_memalign posix_openpt ptsname ptsname_r qsort_r
     random random_r reallocarray realpath rpmatch secure_getenv setenv
     setstate setstate_r srandom srandom_r
     strtod strtol strtold strtoll strtoul strtoull unlockpt unsetenv])
 
   AC_REQUIRE([AC_C_RESTRICT])
 
+  dnl Test whether MB_CUR_MAX needs to be overridden.
+  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_CACHE_CHECK([whether MB_CUR_MAX is correct],
+    [gl_cv_macro_MB_CUR_MAX_good],
+    [
+      dnl Initial guess, used when cross-compiling or when no suitable locale
+      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" ;;
+      esac
+changequote([,])dnl
+      if test $LOCALE_FR_UTF8 != none; then
+        AC_RUN_IFELSE(
+          [AC_LANG_SOURCE([[
+#include <locale.h>
+#include <stdlib.h>
+int main ()
+{
+  int result = 0;
+  if (setlocale (LC_ALL, "$LOCALE_FR_UTF8") != NULL)
+    {
+      if (MB_CUR_MAX < 4)
+        result |= 1;
+    }
+  return result;
+}]])],
+          [gl_cv_macro_MB_CUR_MAX_good=yes],
+          [gl_cv_macro_MB_CUR_MAX_good=no],
+          [:])
+      fi
+    ])
+  case "$gl_cv_macro_MB_CUR_MAX_good" in
+    *yes) ;;
+    *) REPLACE_MB_CUR_MAX=1 ;;
+  esac
+
   AC_CHECK_DECLS_ONCE([ecvt])
   if test $ac_cv_have_decl_ecvt = no; then
     HAVE_DECL_ECVT=0
@@ -78,6 +121,7 @@ AC_DEFUN([gl_STDLIB_H_REQUIRE_DEFAULTS],
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_GRANTPT])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_MALLOC_GNU])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_MALLOC_POSIX])
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_MBSTOWCS])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_MBTOWC])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_MKDTEMP])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_MKOSTEMP])
@@ -131,6 +175,7 @@ AC_DEFUN([gl_STDLIB_H_DEFAULTS],
   HAVE_DECL_FCVT=1;          AC_SUBST([HAVE_DECL_FCVT])
   HAVE_DECL_GCVT=1;          AC_SUBST([HAVE_DECL_GCVT])
   HAVE_DECL_GETLOADAVG=1;    AC_SUBST([HAVE_DECL_GETLOADAVG])
+  HAVE_DECL_PROGRAM_INVOCATION_NAME=1; AC_SUBST([HAVE_DECL_PROGRAM_INVOCATION_NAME])
   HAVE_GETPROGNAME=1;        AC_SUBST([HAVE_GETPROGNAME])
   HAVE_GETSUBOPT=1;          AC_SUBST([HAVE_GETSUBOPT])
   HAVE_GRANTPT=1;            AC_SUBST([HAVE_GRANTPT])
@@ -180,6 +225,8 @@ AC_DEFUN([gl_STDLIB_H_DEFAULTS],
   REPLACE_INITSTATE=0;       AC_SUBST([REPLACE_INITSTATE])
   REPLACE_MALLOC_FOR_MALLOC_GNU=0;    AC_SUBST([REPLACE_MALLOC_FOR_MALLOC_GNU])
   REPLACE_MALLOC_FOR_MALLOC_POSIX=0;  AC_SUBST([REPLACE_MALLOC_FOR_MALLOC_POSIX])
+  REPLACE_MB_CUR_MAX=0;      AC_SUBST([REPLACE_MB_CUR_MAX])
+  REPLACE_MBSTOWCS=0;        AC_SUBST([REPLACE_MBSTOWCS])
   REPLACE_MBTOWC=0;          AC_SUBST([REPLACE_MBTOWC])
   REPLACE_MKOSTEMP=0;        AC_SUBST([REPLACE_MKOSTEMP])
   REPLACE_MKOSTEMPS=0;       AC_SUBST([REPLACE_MKOSTEMPS])
diff --git a/m4/strtoll.m4 b/m4/strtoll.m4
index ede630c6061..ec09609cd42 100644
--- a/m4/strtoll.m4
+++ b/m4/strtoll.m4
@@ -1,4 +1,4 @@
-# strtoll.m4 serial 9
+# strtoll.m4 serial 10
 dnl Copyright (C) 2002, 2004, 2006, 2008-2023 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -24,15 +24,26 @@ AC_DEFUN([gl_FUNC_STRTOLL],
                 if (term != input + 1)
                   result |= 1;
               }
+              /* This test fails on pre-C23 platforms.  */
+              {
+                const char input[] = "0b1";
+                (void) strtoll (input, &term, 2);
+                if (term != input + 3)
+                  result |= 2;
+              }
               return result;
             ]])
          ],
          [gl_cv_func_strtoll_works=yes],
          [gl_cv_func_strtoll_works=no],
          [case "$host_os" in
-                    # Guess no on native Windows.
-            mingw*) gl_cv_func_strtoll_works="guessing no" ;;
-            *)      gl_cv_func_strtoll_works="$gl_cross_guess_normal" ;;
+                                # Guess no on native Windows.
+            mingw*)             gl_cv_func_strtoll_works="guessing no" ;;
+                                # Guess no on glibc systems.
+            *-gnu* | gnu*)      gl_cv_func_strtoll_works="guessing no" ;;
+                                # Guess no on musl systems.
+            *-musl* | midipix*) gl_cv_func_strtoll_works="guessing no" ;;
+            *)                  gl_cv_func_strtoll_works="$gl_cross_guess_normal" ;;
           esac
          ])
     ])
diff --git a/m4/xattr.m4 b/m4/xattr.m4
index 0e179cc0d1d..70bf0db4419 100644
--- a/m4/xattr.m4
+++ b/m4/xattr.m4
@@ -1,5 +1,5 @@
 # xattr.m4 - check for Extended Attributes (Linux)
-# serial 6
+# serial 7
 
 # Copyright (C) 2003-2023 Free Software Foundation, Inc.
 # This file is free software; the Free Software Foundation
@@ -9,7 +9,7 @@
 AC_DEFUN([gl_FUNC_XATTR],
 [
   AC_ARG_ENABLE([xattr],
-        AS_HELP_STRING([--disable-xattr],
+        AS_HELP_STRING([[--disable-xattr]],
                        [do not support extended attributes]),
         [use_xattr=$enableval], [use_xattr=yes])
 
diff --git a/src/alloc.c b/src/alloc.c
index 8d012b1b3b6..d87cc44b59b 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -5351,15 +5351,6 @@ typedef union
 #endif
 } stacktop_sentry;
 
-/* Yield an address close enough to the top of the stack that the
-   garbage collector need not scan above it.  Callers should be
-   declared NO_INLINE.  */
-#ifdef HAVE___BUILTIN_FRAME_ADDRESS
-# define NEAR_STACK_TOP(addr) ((void) (addr), __builtin_frame_address (0))
-#else
-# define NEAR_STACK_TOP(addr) (addr)
-#endif
-
 /* Set *P to the address of the top of the stack.  This must be a
    macro, not a function, so that it is executed in the caller's
    environment.  It is not inside a do-while so that its storage
diff --git a/src/buffer.c b/src/buffer.c
index 242f4509e7d..668c7035724 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -50,6 +50,14 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "w32heap.h"		/* for mmap_* */
 #endif
 
+/* Work around GCC bug 109847
+   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109847
+   which causes GCC to mistakenly complain about
+   AUTO_STRING with "*scratch*".  */
+#if GNUC_PREREQ (13, 0, 0)
+# pragma GCC diagnostic ignored "-Wanalyzer-out-of-bounds"
+#endif
+
 /* This structure holds the default values of the buffer-local variables
    defined with DEFVAR_PER_BUFFER, that have special slots in each buffer.
    The default value occupies the same slot in this structure
diff --git a/src/ccl.c b/src/ccl.c
index 6e780ef9f0c..ce9abd59493 100644
--- a/src/ccl.c
+++ b/src/ccl.c
@@ -605,6 +605,14 @@ do							\
   }							\
 while (0)
 
+/* Work around GCC bug 109579
+   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109579
+   which causes GCC to mistakenly complain about
+   popping the mapping stack.  */
+#if GNUC_PREREQ (13, 0, 0)
+# pragma GCC diagnostic ignored "-Wanalyzer-out-of-bounds"
+#endif
+
 #define POP_MAPPING_STACK(restlen, orig)		\
 do							\
   {							\
diff --git a/src/floatfns.c b/src/floatfns.c
index 13f0ca3e129..e40364f8188 100644
--- a/src/floatfns.c
+++ b/src/floatfns.c
@@ -55,8 +55,6 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #include <math.h>
 
-#include <count-leading-zeros.h>
-
 /* Emacs needs proper handling of +/-inf; correct printing as well as
    important packages depend on it.  Make sure the user didn't specify
    -ffinite-math-only, either directly or implicitly with -Ofast or
@@ -304,14 +302,6 @@ DEFUN ("float", Ffloat, Sfloat, 1, 1, 0,
   return FLOATP (arg) ? arg : make_float (XFLOATINT (arg));
 }
 
-static int
-ecount_leading_zeros (EMACS_UINT x)
-{
-  return (EMACS_UINT_WIDTH == UINT_WIDTH ? count_leading_zeros (x)
-	  : EMACS_UINT_WIDTH == ULONG_WIDTH ? count_leading_zeros_l (x)
-	  : count_leading_zeros_ll (x));
-}
-
 DEFUN ("logb", Flogb, Slogb, 1, 1, 0,
        doc: /* Returns largest integer <= the base 2 log of the magnitude of ARG.
 This is the same as the exponent of a float.  */)
@@ -338,7 +328,7 @@ This is the same as the exponent of a float.  */)
       EMACS_INT i = XFIXNUM (arg);
       if (i == 0)
 	return make_float (-HUGE_VAL);
-      value = EMACS_UINT_WIDTH - 1 - ecount_leading_zeros (eabs (i));
+      value = elogb (eabs (i));
     }
 
   return make_fixnum (value);
diff --git a/src/itree.c b/src/itree.c
index bd3e62a374a..ecf7d67422a 100644
--- a/src/itree.c
+++ b/src/itree.c
@@ -817,14 +817,13 @@ itree_remove_fix (struct itree_tree *tree,
 	{
 	  struct itree_node *other = parent->right;
 
-	  if (null_safe_is_red (other)) /* case 1.a */
+	  if (other->red) /* case 1.a */
 	    {
 	      other->red = false;
 	      parent->red = true;
 	      itree_rotate_left (tree, parent);
 	      other = parent->right;
 	    }
-	  eassume (other != NULL);
 
 	  if (null_safe_is_black (other->left) /* 2.a */
 	      && null_safe_is_black (other->right))
@@ -855,14 +854,13 @@ itree_remove_fix (struct itree_tree *tree,
 	{
 	  struct itree_node *other = parent->left;
 
-	  if (null_safe_is_red (other)) /* 1.b */
+	  if (other->red) /* 1.b */
 	    {
 	      other->red = false;
 	      parent->red = true;
 	      itree_rotate_right (tree, parent);
 	      other = parent->left;
 	    }
-	  eassume (other != NULL);
 
 	  if (null_safe_is_black (other->right) /* 2.b */
 	      && null_safe_is_black (other->left))
diff --git a/src/lisp.h b/src/lisp.h
index 5a07bda3592..79c96e11da8 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -35,6 +35,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #endif
 
 #include <attribute.h>
+#include <count-leading-zeros.h>
 #include <intprops.h>
 #include <verify.h>
 
@@ -3909,6 +3910,20 @@ integer_to_uintmax (Lisp_Object num, uintmax_t *n)
     }
 }
 
+/* Return floor (log2 (N)) as an int, where 0 < N <= ULLONG_MAX.  */
+#if (201112 <= __STDC_VERSION__ && INT_MAX <= UINT_MAX \
+     && LONG_MAX <= ULONG_MAX && LLONG_MAX <= ULLONG_MAX)
+# define elogb(n) \
+    _Generic (+(n), \
+	      int:           UINT_WIDTH   - 1 - count_leading_zeros    (n), \
+	      unsigned int:  UINT_WIDTH   - 1 - count_leading_zeros    (n), \
+	      long:          ULONG_WIDTH  - 1 - count_leading_zeros_l  (n), \
+	      unsigned long: ULONG_WIDTH  - 1 - count_leading_zeros_l  (n), \
+	      default:       ULLONG_WIDTH - 1 - count_leading_zeros_ll (n))
+#else
+# define elogb(n) (ULLONG_WIDTH - 1 - count_leading_zeros_ll (n))
+#endif
+
 /* A modification count.  These are wide enough, and incremented
    rarely enough, so that they should never overflow a 60-bit counter
    in practice, and the code below assumes this so a compiler can
@@ -3918,11 +3933,12 @@ typedef intmax_t modiff_count;
 INLINE modiff_count
 modiff_incr (modiff_count *a, ptrdiff_t len)
 {
-  modiff_count a0 = *a; int incr = len ? 1 : 0;
+  modiff_count a0 = *a;
   /* Increase the counter more for a large modification and less for a
      small modification.  Increase it logarithmically to avoid
      increasing it too much.  */
-  while (len >>= 1) incr++;
+  verify (PTRDIFF_MAX <= ULLONG_MAX);
+  int incr = len == 0 ? 1 : elogb (len) + 1;
   bool modiff_overflow = INT_ADD_WRAPV (a0, incr, a);
   eassert (!modiff_overflow && *a >> 30 >> 30 == 0);
   return a0;
@@ -5421,6 +5437,14 @@ safe_free_unbind_to (specpdl_ref count, specpdl_ref sa_count, Lisp_Object val)
   return unbind_to (count, val);
 }
 
+/* Work around GCC bug 109577
+   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109577
+   which causes GCC to mistakenly complain about the
+   memory allocation in SAFE_ALLOCA_LISP_EXTRA.  */
+#if GNUC_PREREQ (13, 0, 0)
+# pragma GCC diagnostic ignored "-Wanalyzer-allocation-size"
+#endif
+
 /* Set BUF to point to an allocated array of NELT Lisp_Objects,
    immediately followed by EXTRA spare bytes.  */
 
diff --git a/src/pdumper.c b/src/pdumper.c
index 628f43beb39..04e3b66b0c2 100644
--- a/src/pdumper.c
+++ b/src/pdumper.c
@@ -103,7 +103,6 @@ verify (sizeof (intptr_t) == sizeof (ptrdiff_t));
 verify (sizeof (void (*) (void)) == sizeof (void *));
 verify (sizeof (ptrdiff_t) <= sizeof (Lisp_Object));
 verify (sizeof (ptrdiff_t) <= sizeof (EMACS_INT));
-verify (CHAR_BIT == 8);
 
 static size_t
 divide_round_up (size_t x, size_t y)
@@ -133,6 +132,7 @@ static int nr_remembered_data = 0;
 typedef int_least32_t dump_off;
 #define DUMP_OFF_MIN INT_LEAST32_MIN
 #define DUMP_OFF_MAX INT_LEAST32_MAX
+#define DUMP_OFF_WIDTH INT_LEAST32_WIDTH
 #define PRIdDUMP_OFF PRIdLEAST32
 
 enum { EMACS_INT_XDIGITS = (EMACS_INT_WIDTH + 3) / 4 };
@@ -222,8 +222,7 @@ enum emacs_reloc_type
 enum
   {
    EMACS_RELOC_TYPE_BITS = 3,
-   EMACS_RELOC_LENGTH_BITS = (sizeof (dump_off) * CHAR_BIT
-			      - EMACS_RELOC_TYPE_BITS)
+   EMACS_RELOC_LENGTH_BITS = DUMP_OFF_WIDTH - EMACS_RELOC_TYPE_BITS
   };
 
 struct emacs_reloc
@@ -273,7 +272,7 @@ enum
       dump.  Always suitable for heap objects; may be more aligned.  */
    DUMP_ALIGNMENT = max (GCALIGNMENT, DUMP_RELOCATION_ALIGNMENT),
 
-   DUMP_RELOC_OFFSET_BITS = sizeof (dump_off) * CHAR_BIT - DUMP_RELOC_TYPE_BITS
+   DUMP_RELOC_OFFSET_BITS = DUMP_OFF_WIDTH - DUMP_RELOC_TYPE_BITS
   };
 
 verify (RELOC_DUMP_TO_EMACS_LV + 8 < (1 << DUMP_RELOC_TYPE_BITS));
@@ -5001,6 +5000,7 @@ dump_mmap_contiguous (struct dump_memory_map *maps, int nr_maps)
 }
 
 typedef uint_fast32_t dump_bitset_word;
+#define DUMP_BITSET_WORD_WIDTH UINT_FAST32_WIDTH
 
 struct dump_bitset
 {
@@ -5011,9 +5011,9 @@ struct dump_bitset
 static bool
 dump_bitsets_init (struct dump_bitset bitset[2], size_t number_bits)
 {
-  int xword_size = sizeof (bitset[0].bits[0]);
-  int bits_per_word = xword_size * CHAR_BIT;
-  ptrdiff_t words_needed = divide_round_up (number_bits, bits_per_word);
+  int xword_size = sizeof (dump_bitset_word);
+  ptrdiff_t words_needed = divide_round_up (number_bits,
+					    DUMP_BITSET_WORD_WIDTH);
   dump_bitset_word *bits = calloc (words_needed, 2 * xword_size);
   if (!bits)
     return false;
@@ -5028,9 +5028,7 @@ static dump_bitset_word *
 dump_bitset__bit_slot (const struct dump_bitset *bitset,
                        size_t bit_number)
 {
-  int xword_size = sizeof (bitset->bits[0]);
-  int bits_per_word = xword_size * CHAR_BIT;
-  ptrdiff_t word_number = bit_number / bits_per_word;
+  ptrdiff_t word_number = bit_number / DUMP_BITSET_WORD_WIDTH;
   eassert (word_number < bitset->number_words);
   return &bitset->bits[word_number];
 }
@@ -5039,10 +5037,8 @@ static bool
 dump_bitset_bit_set_p (const struct dump_bitset *bitset,
                        size_t bit_number)
 {
-  unsigned xword_size = sizeof (bitset->bits[0]);
-  unsigned bits_per_word = xword_size * CHAR_BIT;
   dump_bitset_word bit = 1;
-  bit <<= bit_number % bits_per_word;
+  bit <<= bit_number % DUMP_BITSET_WORD_WIDTH;
   return *dump_bitset__bit_slot (bitset, bit_number) & bit;
 }
 
@@ -5051,11 +5047,9 @@ dump_bitset__set_bit_value (struct dump_bitset *bitset,
                             size_t bit_number,
                             bool bit_is_set)
 {
-  int xword_size = sizeof (bitset->bits[0]);
-  int bits_per_word = xword_size * CHAR_BIT;
   dump_bitset_word *slot = dump_bitset__bit_slot (bitset, bit_number);
   dump_bitset_word bit = 1;
-  bit <<= bit_number % bits_per_word;
+  bit <<= bit_number % DUMP_BITSET_WORD_WIDTH;
   if (bit_is_set)
     *slot = *slot | bit;
   else
diff --git a/src/print.c b/src/print.c
index d656774b9cd..940ec7312bf 100644
--- a/src/print.c
+++ b/src/print.c
@@ -2207,9 +2207,9 @@ print_object (Lisp_Object obj, Lisp_Object printcharfun, bool escapeflag)
   char buf[max (sizeof "from..to..in " + 2 * INT_STRLEN_BOUND (EMACS_INT),
 		max (sizeof " . #" + INT_STRLEN_BOUND (intmax_t),
 		     max ((sizeof " with data 0x"
-			   + (sizeof (uintmax_t) * CHAR_BIT + 4 - 1) / 4),
+			   + (UINTMAX_WIDTH + 4 - 1) / 4),
 			  40)))];
-  current_thread->stack_top = buf;
+  current_thread->stack_top = NEAR_STACK_TOP (buf);
 
  print_obj:
   maybe_quit ();
diff --git a/src/sort.c b/src/sort.c
index 34d0d690198..706c057dab0 100644
--- a/src/sort.c
+++ b/src/sort.c
@@ -40,7 +40,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
    minimal length.  So the number of bits in a ptrdiff_t is plenty large
    enough for all cases.  */
 
-#define MAX_MERGE_PENDING (sizeof (ptrdiff_t)  * 8)
+#define MAX_MERGE_PENDING PTRDIFF_WIDTH
 
 /* Once we get into galloping mode, we stay there as long as both runs
    win at least GALLOP_WIN_MIN consecutive times.  */
diff --git a/src/term.c b/src/term.c
index 3b5619ff93e..44f6c5918b9 100644
--- a/src/term.c
+++ b/src/term.c
@@ -3387,7 +3387,7 @@ tty_menu_activate (tty_menu *menu, int *pane, int *selidx,
 		       active submenu.  */
 		    if (i != statecount - 2
 			|| state[i].menu->submenu[dy] != state[i + 1].menu)
-		      while (i != statecount - 1)
+		      while (i < statecount - 1)
 			{
 			  statecount--;
 			  screen_update (sf, state[statecount].screen_behind);
diff --git a/src/thread.h b/src/thread.h
index f0e9ee01173..9b14cc44f35 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -33,6 +33,15 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "sysselect.h"		/* FIXME */
 #include "systhread.h"
 
+/* Yield an address close enough to the top of the stack that the
+   garbage collector need not scan above it.  Callers should be
+   declared NO_INLINE.  */
+#ifdef HAVE___BUILTIN_FRAME_ADDRESS
+# define NEAR_STACK_TOP(addr) ((void) (addr), __builtin_frame_address (0))
+#else
+# define NEAR_STACK_TOP(addr) (addr)
+#endif
+
 INLINE_HEADER_BEGIN
 
 /* Byte-code interpreter thread state.  */