Update from Gnulib

This incorporates:
2020-08-16 time_rz: remove unused functions
2020-08-16 time_rz: fix issues with mktime_z failures
2020-08-16 nstrftime: Guide inlining also on clang
2020-08-16 intprops: Avoid bogus warning on clang
2020-08-16 libc-config: Enable __REDIRECT macro also on clang
2020-08-16 regex: Use initializer shorthand syntax also with clang
2020-08-16 regex: Use space optimization also with clang
2020-08-16 Use _Static_assert and static_assert when present on clang
2020-08-16 Use 'throw ()' for optimization in C++ mode also on clang
2020-08-16 stdio: Don't break attribute 'scanf' on clang
2020-08-16 Fix "warning: 'format' attribute ...: rpl_printf"
2020-08-16 Fix "warning: attribute declaration must precede definition"
2020-08-16 Fix undesired warnings
2020-08-16 Don't use Autoconf quadrigraphsxo
2020-08-16 Fix quoting of AC_LANG_PROGRAM arguments
2020-08-16 Assume autoconf >= 2.64
2020-08-15 nstrftime: be more predictable about errno
2020-08-15 canonicalize: Fix autoconf test on MSVC/clang
2020-08-15 Support compiling without -loldnames on native Windows
2020-08-14 mktime, mktime-internal: Remove obsolete code
2020-08-14 Assume tzset exists
* lib/c++defs.h, lib/canonicalize-lgpl.c, lib/cdefs.h, lib/dup2.c:
* lib/fcntl.in.h, lib/getopt-cdefs.in.h, lib/intprops.h, lib/md5.h:
* lib/mktime.c, lib/nstrftime.c, lib/open.c, lib/regcomp.c:
* lib/regex_internal.h, lib/stdio.in.h, lib/stdlib.in.h:
* lib/strftime.h, lib/string.in.h, lib/sys_select.in.h:
* lib/sys_stat.in.h, lib/sys_time.in.h, lib/time.in.h, lib/time_rz.c:
* lib/unistd.in.h, lib/verify.h, m4/00gnulib.m4:
* m4/absolute-header.m4, m4/alloca.m4, m4/canonicalize.m4, m4/dup2.m4:
* m4/fchmodat.m4, m4/fcntl.m4, m4/fdopendir.m4, m4/fpending.m4:
* m4/futimens.m4, m4/getdtablesize.m4, m4/getloadavg.m4:
* m4/gnulib-common.m4, m4/include_next.m4, m4/largefile.m4:
* m4/manywarnings.m4, m4/mktime.m4, m4/nstrftime.m4, m4/open-slash.m4:
* m4/pselect.m4, m4/pthread_sigmask.m4, m4/time_h.m4, m4/utimens.m4:
* m4/utimensat.m4, m4/utimes.m4, m4/warnings.m4:
Copy from Gnulib.
* lib/gnulib.mk.in: Regenerate.

25 files changed, 379 insertions, 70 deletions

diff --git a/lib/c++defs.h b/lib/c++defs.h
index 90e6fd62e6d..6a9bf295eb5 100644
--- a/lib/c++defs.h
+++ b/lib/c++defs.h
@@ -146,6 +146,16 @@
     _GL_EXTERN_C int _gl_cxxalias_dummy
 #endif
 
+/* _GL_CXXALIAS_MDA (func, rettype, parameters);
+   is to be used when func is a Microsoft deprecated alias, on native Windows.
+   It declares a C++ alias called GNULIB_NAMESPACE::func
+   that redirects to _func, if GNULIB_NAMESPACE is defined.
+   Example:
+     _GL_CXXALIAS_MDA (open, int, (const char *filename, int flags, ...));
+ */
+#define _GL_CXXALIAS_MDA(func,rettype,parameters) \
+  _GL_CXXALIAS_RPL_1 (func, _##func, rettype, parameters)
+
 /* _GL_CXXALIAS_RPL_CAST_1 (func, rpl_func, rettype, parameters);
    is like  _GL_CXXALIAS_RPL_1 (func, rpl_func, rettype, parameters);
    except that the C function rpl_func may have a slightly different
diff --git a/lib/canonicalize-lgpl.c b/lib/canonicalize-lgpl.c
index 9f990988393..0b89d2a1842 100644
--- a/lib/canonicalize-lgpl.c
+++ b/lib/canonicalize-lgpl.c
@@ -52,7 +52,9 @@
 # include "pathmax.h"
 # include "malloca.h"
 # include "filename.h"
-# if HAVE_GETCWD
+# if defined _WIN32 && !defined __CYGWIN__
+#  define __getcwd _getcwd
+# elif HAVE_GETCWD
 #  if IN_RELOCWRAPPER
     /* When building the relocatable program wrapper, use the system's getcwd
        function, not the gnulib override, otherwise we would get a link error.
diff --git a/lib/cdefs.h b/lib/cdefs.h
index 4f89f4e4bf0..0cc27806a19 100644
--- a/lib/cdefs.h
+++ b/lib/cdefs.h
@@ -85,7 +85,7 @@
 #  define __NTH(fct)    __attribute__ ((__nothrow__ __LEAF)) fct
 #  define __NTHNL(fct)  __attribute__ ((__nothrow__)) fct
 # else
-#  if defined __cplusplus && __GNUC_PREREQ (2,8)
+#  if defined __cplusplus && (__GNUC_PREREQ (2,8) || __clang_major >= 4)
 #   define __THROW      throw ()
 #   define __THROWNL    throw ()
 #   define __NTH(fct)   __LEAF_ATTR fct throw ()
@@ -194,7 +194,7 @@
    Example:
    int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */
 
-#if defined __GNUC__ && __GNUC__ >= 2
+#if (defined __GNUC__ && __GNUC__ >= 2) || (__clang_major__ >= 4)
 
 # define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias))
 # ifdef __cplusplus
@@ -465,7 +465,8 @@
 
 #if (!defined _Static_assert && !defined __cplusplus \
      && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 201112 \
-     && (!__GNUC_PREREQ (4, 6) || defined __STRICT_ANSI__))
+     && (!(__GNUC_PREREQ (4, 6) || __clang_major__ >= 4) \
+         || defined __STRICT_ANSI__))
 # define _Static_assert(expr, diagnostic) \
     extern int (*__Static_assert_function (void)) \
       [!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })]
diff --git a/lib/dup2.c b/lib/dup2.c
index 9bc3951f3d2..323e19b25ec 100644
--- a/lib/dup2.c
+++ b/lib/dup2.c
@@ -52,7 +52,7 @@ dup2_nothrow (int fd, int desired_fd)
 
   TRY_MSVC_INVAL
     {
-      result = dup2 (fd, desired_fd);
+      result = _dup2 (fd, desired_fd);
     }
   CATCH_MSVC_INVAL
     {
@@ -64,7 +64,7 @@ dup2_nothrow (int fd, int desired_fd)
   return result;
 }
 # else
-#  define dup2_nothrow dup2
+#  define dup2_nothrow _dup2
 # endif
 
 static int
diff --git a/lib/fcntl.in.h b/lib/fcntl.in.h
index 0a21c957baf..6f16bc66921 100644
--- a/lib/fcntl.in.h
+++ b/lib/fcntl.in.h
@@ -97,6 +97,12 @@
 _GL_FUNCDECL_RPL (creat, int, (const char *filename, mode_t mode)
                              _GL_ARG_NONNULL ((1)));
 _GL_CXXALIAS_RPL (creat, int, (const char *filename, mode_t mode));
+# elif defined _WIN32 && !defined __CYGWIN__
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef creat
+#   define creat _creat
+#  endif
+_GL_CXXALIAS_MDA (creat, int, (const char *filename, mode_t mode));
 # else
 _GL_CXXALIAS_SYS (creat, int, (const char *filename, mode_t mode));
 # endif
@@ -106,6 +112,9 @@ _GL_CXXALIASWARN (creat);
 /* Assume creat is always declared.  */
 _GL_WARN_ON_USE (creat, "creat is not always POSIX compliant - "
                  "use gnulib module creat for portability");
+#elif defined _WIN32 && !defined __CYGWIN__
+# undef creat
+# define creat _creat
 #endif
 
 #if @GNULIB_FCNTL@
@@ -146,6 +155,12 @@ _GL_WARN_ON_USE (fcntl, "fcntl is not always POSIX compliant - "
 _GL_FUNCDECL_RPL (open, int, (const char *filename, int flags, ...)
                              _GL_ARG_NONNULL ((1)));
 _GL_CXXALIAS_RPL (open, int, (const char *filename, int flags, ...));
+# elif defined _WIN32 && !defined __CYGWIN__
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef open
+#   define open _open
+#  endif
+_GL_CXXALIAS_MDA (open, int, (const char *filename, int flags, ...));
 # else
 _GL_CXXALIAS_SYS (open, int, (const char *filename, int flags, ...));
 # endif
@@ -159,6 +174,9 @@ _GL_CXXALIASWARN (open);
 /* Assume open is always declared.  */
 _GL_WARN_ON_USE (open, "open is not always POSIX compliant - "
                  "use gnulib module open for portability");
+#elif defined _WIN32 && !defined __CYGWIN__
+# undef open
+# define open _open
 #endif
 
 #if @GNULIB_OPENAT@
diff --git a/lib/getopt-cdefs.in.h b/lib/getopt-cdefs.in.h
index c510ab163c3..674838c666a 100644
--- a/lib/getopt-cdefs.in.h
+++ b/lib/getopt-cdefs.in.h
@@ -57,7 +57,7 @@
 #endif
 
 #ifndef __THROW
-# if defined __cplusplus && __GNUC_PREREQ (2,8)
+# if defined __cplusplus && (__GNUC_PREREQ (2,8) || __clang_major__ >= 4)
 #  define __THROW       throw ()
 # else
 #  define __THROW
diff --git a/lib/gnulib.mk.in b/lib/gnulib.mk.in
index 92d0621c61a..7b4fc74219f 100644
--- a/lib/gnulib.mk.in
+++ b/lib/gnulib.mk.in
@@ -682,7 +682,6 @@ HAVE_SYS_TYPES_H = @HAVE_SYS_TYPES_H@
 HAVE_TIMEGM = @HAVE_TIMEGM@
 HAVE_TIMEZONE_T = @HAVE_TIMEZONE_T@
 HAVE_TYPE_VOLATILE_SIG_ATOMIC_T = @HAVE_TYPE_VOLATILE_SIG_ATOMIC_T@
-HAVE_TZSET = @HAVE_TZSET@
 HAVE_UNISTD_H = @HAVE_UNISTD_H@
 HAVE_UNLINKAT = @HAVE_UNLINKAT@
 HAVE_UNLOCKPT = @HAVE_UNLOCKPT@
@@ -1159,7 +1158,7 @@ ifeq (,$(OMIT_GNULIB_MODULE_absolute-header))
 # Use this preprocessor expression to decide whether #include_next works.
 # Do not rely on a 'configure'-time test for this, since the expression
 # might appear in an installed header, which is used by some other compiler.
-HAVE_INCLUDE_NEXT = (__GNUC__ || 60000000 <= __DECC_VER)
+HAVE_INCLUDE_NEXT = (__GNUC__ || __clang__ || 60000000 <= __DECC_VER)
 
 endif
 ## end   gnulib module absolute-header
@@ -3185,7 +3184,6 @@ time.h: time.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H) $(
               -e 's|@''HAVE_STRPTIME''@|$(HAVE_STRPTIME)|g' \
               -e 's|@''HAVE_TIMEGM''@|$(HAVE_TIMEGM)|g' \
               -e 's|@''HAVE_TIMEZONE_T''@|$(HAVE_TIMEZONE_T)|g' \
-              -e 's|@''HAVE_TZSET''@|$(HAVE_TZSET)|g' \
               -e 's|@''REPLACE_CTIME''@|$(REPLACE_CTIME)|g' \
               -e 's|@''REPLACE_GMTIME''@|$(REPLACE_GMTIME)|g' \
               -e 's|@''REPLACE_LOCALTIME''@|$(REPLACE_LOCALTIME)|g' \
diff --git a/lib/intprops.h b/lib/intprops.h
index 220f532e499..f2f70b3e733 100644
--- a/lib/intprops.h
+++ b/lib/intprops.h
@@ -396,7 +396,7 @@
    For now, assume all versions of GCC-like compilers generate bogus
    warnings for _Generic.  This matters only for compilers that
    lack relevant builtins.  */
-#if __GNUC__
+#if __GNUC__ || defined __clang__
 # define _GL__GENERIC_BOGUS 1
 #else
 # define _GL__GENERIC_BOGUS 0
diff --git a/lib/md5.h b/lib/md5.h
index 3c6048242b0..c728ba1b6f2 100644
--- a/lib/md5.h
+++ b/lib/md5.h
@@ -40,7 +40,7 @@
 #endif
 
 #ifndef __THROW
-# if defined __cplusplus && __GNUC_PREREQ (2,8)
+# if defined __cplusplus && (__GNUC_PREREQ (2,8) || __clang_major__ >= 4)
 #  define __THROW       throw ()
 # else
 #  define __THROW
diff --git a/lib/mktime.c b/lib/mktime.c
index 92c00b2b14b..5b4c144ecad 100644
--- a/lib/mktime.c
+++ b/lib/mktime.c
@@ -94,7 +94,7 @@ my_tzset (void)
   const char *tz = getenv ("TZ");
   if (tz != NULL && strchr (tz, '/') != NULL)
     _putenv ("TZ=");
-# elif HAVE_TZSET
+# else
   tzset ();
 # endif
 }
diff --git a/lib/nstrftime.c b/lib/nstrftime.c
index 2816cf4d58b..7d5a97f7635 100644
--- a/lib/nstrftime.c
+++ b/lib/nstrftime.c
@@ -21,7 +21,6 @@
 # define HAVE_TM_GMTOFF 1
 # define HAVE_TM_ZONE 1
 # define HAVE_TZNAME 1
-# define HAVE_TZSET 1
 # include "../locale/localeinfo.h"
 #else
 # include <config.h>
@@ -34,6 +33,7 @@
 #endif
 
 #include <ctype.h>
+#include <errno.h>
 #include <time.h>
 
 #if HAVE_TZNAME && !HAVE_DECL_TZNAME
@@ -163,7 +163,10 @@ extern char *tzname[];
       size_t _w = pad == L_('-') || width < 0 ? 0 : width;                    \
       size_t _incr = _n < _w ? _w : _n;                                       \
       if (_incr >= maxsize - i)                                               \
-        return 0;                                                             \
+        {                                                                     \
+          errno = ERANGE;                                                     \
+          return 0;                                                           \
+        }                                                                     \
       if (p)                                                                  \
         {                                                                     \
           if (_n < _w)                                                        \
@@ -365,7 +368,7 @@ tm_diff (const struct tm *a, const struct tm *b)
 #define ISO_WEEK1_WDAY 4 /* Thursday */
 #define YDAY_MINIMUM (-366)
 static int iso_week_days (int, int);
-#ifdef __GNUC__
+#if defined __GNUC__ || defined __clang__
 __inline__
 #endif
 static int
@@ -389,7 +392,6 @@ iso_week_days (int yday, int wday)
 #endif
 
 #ifdef my_strftime
-# undef HAVE_TZSET
 # define extra_args , tz, ns
 # define extra_args_spec , timezone_t tz, int ns
 #else
@@ -449,6 +451,7 @@ __strftime_internal (STREAM_OR_CHAR_T *s, STRFTIME_ARG (size_t maxsize)
   size_t maxsize = (size_t) -1;
 #endif
 
+  int saved_errno = errno;
   int hour12 = tp->tm_hour;
 #ifdef _NL_CURRENT
   /* We cannot make the following values variables since we must delay
@@ -523,7 +526,7 @@ __strftime_internal (STREAM_OR_CHAR_T *s, STRFTIME_ARG (size_t maxsize)
     {
       /* POSIX.1 requires that local time zone information be used as
          though strftime called tzset.  */
-# if HAVE_TZSET
+# ifndef my_strftime
       if (!*tzset_called)
         {
           tzset ();
@@ -1188,7 +1191,13 @@ __strftime_internal (STREAM_OR_CHAR_T *s, STRFTIME_ARG (size_t maxsize)
             time_t t;
 
             ltm = *tp;
+            ltm.tm_yday = -1;
             t = mktime_z (tz, &ltm);
+            if (ltm.tm_yday < 0)
+              {
+                errno = EOVERFLOW;
+                return 0;
+              }
 
             /* Generate string value for T using time_t arithmetic;
                this works even if sizeof (long) < sizeof (time_t).  */
@@ -1417,7 +1426,7 @@ __strftime_internal (STREAM_OR_CHAR_T *s, STRFTIME_ARG (size_t maxsize)
 
                 /* POSIX.1 requires that local time zone information be used as
                    though strftime called tzset.  */
-# if HAVE_TZSET
+# ifndef my_strftime
                 if (!*tzset_called)
                   {
                     tzset ();
@@ -1486,5 +1495,6 @@ __strftime_internal (STREAM_OR_CHAR_T *s, STRFTIME_ARG (size_t maxsize)
     *p = L_('\0');
 #endif
 
+  errno = saved_errno;
   return i;
 }
diff --git a/lib/open.c b/lib/open.c
index 751b42d7dcf..0f7c6e9b9d3 100644
--- a/lib/open.c
+++ b/lib/open.c
@@ -30,7 +30,11 @@
 static int
 orig_open (const char *filename, int flags, mode_t mode)
 {
+#if defined _WIN32 && !defined __CYGWIN__
+  return _open (filename, flags, mode);
+#else
   return open (filename, flags, mode);
+#endif
 }
 
 /* Specification.  */
diff --git a/lib/regcomp.c b/lib/regcomp.c
index 84044be5e09..a4b95b0b2ff 100644
--- a/lib/regcomp.c
+++ b/lib/regcomp.c
@@ -558,7 +558,7 @@ weak_alias (__regerror, regerror)
 static const bitset_t utf8_sb_map =
 {
   /* Set the first 128 bits.  */
-# if defined __GNUC__ && !defined __STRICT_ANSI__
+# if (defined __GNUC__ || __clang_major__ >= 4) && !defined __STRICT_ANSI__
   [0 ... 0x80 / BITSET_WORD_BITS - 1] = BITSET_WORD_MAX
 # else
 #  if 4 * BITSET_WORD_BITS < ASCII_CHARS
diff --git a/lib/regex_internal.h b/lib/regex_internal.h
index 9a0c2ed97c8..0c72e3f7b01 100644
--- a/lib/regex_internal.h
+++ b/lib/regex_internal.h
@@ -335,7 +335,7 @@ typedef struct
     Idx idx;                    /* for BACK_REF */
     re_context_type ctx_type;   /* for ANCHOR */
   } opr;
-#if __GNUC__ >= 2 && !defined __STRICT_ANSI__
+#if (__GNUC__ >= 2 || defined __clang__) && !defined __STRICT_ANSI__
   re_token_type_t type : 8;
 #else
   re_token_type_t type;
diff --git a/lib/stdio.in.h b/lib/stdio.in.h
index cbebc8462fd..6d12cd826de 100644
--- a/lib/stdio.in.h
+++ b/lib/stdio.in.h
@@ -215,6 +215,11 @@ _GL_WARN_ON_USE (fclose, "fclose is not always POSIX compliant - "
                  "use gnulib module fclose for portable POSIX compliance");
 #endif
 
+#if defined _WIN32 && !defined __CYGWIN__
+# undef fcloseall
+# define fcloseall _fcloseall
+#endif
+
 #if @GNULIB_FDOPEN@
 # if @REPLACE_FDOPEN@
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
@@ -224,6 +229,12 @@ _GL_WARN_ON_USE (fclose, "fclose is not always POSIX compliant - "
 _GL_FUNCDECL_RPL (fdopen, FILE *, (int fd, const char *mode)
                                   _GL_ARG_NONNULL ((2)));
 _GL_CXXALIAS_RPL (fdopen, FILE *, (int fd, const char *mode));
+# elif defined _WIN32 && !defined __CYGWIN__
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef fdopen
+#   define fdopen _fdopen
+#  endif
+_GL_CXXALIAS_MDA (fdopen, FILE *, (int fd, const char *mode));
 # else
 _GL_CXXALIAS_SYS (fdopen, FILE *, (int fd, const char *mode));
 # endif
@@ -233,6 +244,9 @@ _GL_CXXALIASWARN (fdopen);
 /* Assume fdopen is always declared.  */
 _GL_WARN_ON_USE (fdopen, "fdopen on native Windows platforms is not POSIX compliant - "
                  "use gnulib module fdopen for portability");
+#elif defined _WIN32 && !defined __CYGWIN__
+# undef fdopen
+# define fdopen _fdopen
 #endif
 
 #if @GNULIB_FFLUSH@
@@ -297,6 +311,11 @@ _GL_CXXALIASWARN (fgets);
 # endif
 #endif
 
+#if defined _WIN32 && !defined __CYGWIN__
+# undef fileno
+# define fileno _fileno
+#endif
+
 #if @GNULIB_FOPEN@
 # if @REPLACE_FOPEN@
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
@@ -824,6 +843,11 @@ _GL_WARN_ON_USE (getline, "getline is unportable - "
 _GL_WARN_ON_USE (gets, "gets is a security hole - use fgets instead");
 #endif
 
+#if defined _WIN32 && !defined __CYGWIN__
+# undef getw
+# define getw _getw
+#endif
+
 #if @GNULIB_OBSTACK_PRINTF@ || @GNULIB_OBSTACK_PRINTF_POSIX@
 struct obstack;
 /* Grow an obstack with formatted output.  Return the number of
@@ -940,7 +964,7 @@ _GL_WARN_ON_USE (popen, "popen is buggy on some platforms - "
 #if @GNULIB_PRINTF_POSIX@ || @GNULIB_PRINTF@
 # if (@GNULIB_PRINTF_POSIX@ && @REPLACE_PRINTF@) \
      || (@GNULIB_PRINTF@ && @REPLACE_STDIO_WRITE_FUNCS@ && (@GNULIB_STDIO_H_NONBLOCKING@ || @GNULIB_STDIO_H_SIGPIPE@))
-#  if defined __GNUC__
+#  if defined __GNUC__ || defined __clang__
 #   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 /* Don't break __attribute__((format(printf,M,N))).  */
 #    define printf __printf__
@@ -1037,6 +1061,11 @@ _GL_CXXALIASWARN (puts);
 # endif
 #endif
 
+#if defined _WIN32 && !defined __CYGWIN__
+# undef putw
+# define putw _putw
+#endif
+
 #if @GNULIB_REMOVE@
 # if @REPLACE_REMOVE@
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
@@ -1114,7 +1143,7 @@ _GL_WARN_ON_USE (renameat, "renameat is not portable - "
 
 #if @GNULIB_SCANF@
 # if @REPLACE_STDIO_READ_FUNCS@ && @GNULIB_STDIO_H_NONBLOCKING@
-#  if defined __GNUC__
+#  if defined __GNUC__ || defined __clang__
 #   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 #    undef scanf
 /* Don't break __attribute__((format(scanf,M,N))).  */
@@ -1170,7 +1199,9 @@ _GL_CXXALIAS_SYS (snprintf, int,
                   (char *restrict str, size_t size,
                    const char *restrict format, ...));
 # endif
+# if __GLIBC__ >= 2
 _GL_CXXALIASWARN (snprintf);
+# endif
 #elif defined GNULIB_POSIXCHECK
 # undef snprintf
 # if HAVE_RAW_DECL_SNPRINTF
@@ -1214,6 +1245,11 @@ _GL_WARN_ON_USE (sprintf, "sprintf is not always POSIX compliant - "
                  "POSIX compliance");
 #endif
 
+#if defined _WIN32 && !defined __CYGWIN__
+# undef tempnam
+# define tempnam _tempnam
+#endif
+
 #if @GNULIB_TMPFILE@
 # if @REPLACE_TMPFILE@
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
@@ -1382,7 +1418,9 @@ _GL_CXXALIAS_SYS (vfscanf, int,
                   (FILE *restrict stream,
                    const char *restrict format, va_list args));
 # endif
+# if __GLIBC__ >= 2
 _GL_CXXALIASWARN (vfscanf);
+# endif
 #endif
 
 #if @GNULIB_VPRINTF_POSIX@ || @GNULIB_VPRINTF@
@@ -1436,7 +1474,9 @@ _GL_CXXALIAS_RPL (vscanf, int, (const char *restrict format, va_list args));
 # else
 _GL_CXXALIAS_SYS (vscanf, int, (const char *restrict format, va_list args));
 # endif
+# if __GLIBC__ >= 2
 _GL_CXXALIASWARN (vscanf);
+# endif
 #endif
 
 #if @GNULIB_VSNPRINTF@
@@ -1464,7 +1504,9 @@ _GL_CXXALIAS_SYS (vsnprintf, int,
                   (char *restrict str, size_t size,
                    const char *restrict format, va_list args));
 # endif
+# if __GLIBC__ >= 2
 _GL_CXXALIASWARN (vsnprintf);
+# endif
 #elif defined GNULIB_POSIXCHECK
 # undef vsnprintf
 # if HAVE_RAW_DECL_VSNPRINTF
diff --git a/lib/stdlib.in.h b/lib/stdlib.in.h
index 5c598a275d1..47a1309e633 100644
--- a/lib/stdlib.in.h
+++ b/lib/stdlib.in.h
@@ -217,6 +217,21 @@ _GL_WARN_ON_USE (canonicalize_file_name,
 # endif
 #endif
 
+#if defined _WIN32 && !defined __CYGWIN__
+# undef ecvt
+# define ecvt _ecvt
+#endif
+
+#if defined _WIN32 && !defined __CYGWIN__
+# undef fcvt
+# define fcvt _fcvt
+#endif
+
+#if defined _WIN32 && !defined __CYGWIN__
+# undef gcvt
+# define gcvt _gcvt
+#endif
+
 #if @GNULIB_GETLOADAVG@
 /* Store max(NELEM,3) load average numbers in LOADAVG[].
    The three numbers are the load average of the last 1 minute, the last 5
@@ -468,6 +483,11 @@ _GL_WARN_ON_USE (mkstemps, "mkstemps is unportable - "
 # endif
 #endif
 
+#if defined _WIN32 && !defined __CYGWIN__
+# undef mktemp
+# define mktemp _mktemp
+#endif
+
 #if @GNULIB_POSIX_OPENPT@
 /* Return an FD open to the master side of a pseudo-terminal.  Flags should
    include O_RDWR, and may also include O_NOCTTY.  */
@@ -546,10 +566,19 @@ _GL_WARN_ON_USE (ptsname_r, "ptsname_r is not portable - "
 #  endif
 _GL_FUNCDECL_RPL (putenv, int, (char *string) _GL_ARG_NONNULL ((1)));
 _GL_CXXALIAS_RPL (putenv, int, (char *string));
+# elif defined _WIN32 && !defined __CYGWIN__
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef putenv
+#   define putenv _putenv
+#  endif
+_GL_CXXALIAS_MDA (putenv, int, (char *string));
 # else
 _GL_CXXALIAS_SYS (putenv, int, (char *string));
 # endif
 _GL_CXXALIASWARN (putenv);
+#elif defined _WIN32 && !defined __CYGWIN__
+# undef putenv
+# define putenv _putenv
 #endif
 
 #if @GNULIB_QSORT_R@
diff --git a/lib/strftime.h b/lib/strftime.h
index e8501631573..fe0c4195a59 100644
--- a/lib/strftime.h
+++ b/lib/strftime.h
@@ -24,7 +24,12 @@ extern "C" {
 /* Just like strftime, but with two more arguments:
    POSIX requires that strftime use the local timezone information.
    Use the timezone __TZ instead.  Use __NS as the number of
-   nanoseconds in the %N directive.  */
+   nanoseconds in the %N directive.
+
+   On error, set errno and return 0.  Otherwise, return the number of
+   bytes generated (not counting the trailing NUL), preserving errno
+   if the number is 0.  This errno behavior is in draft POSIX 202x
+   plus some requested changes to POSIX.  */
 size_t nstrftime (char *restrict, size_t, char const *, struct tm const *,
                   timezone_t __tz, int __ns);
 
diff --git a/lib/string.in.h b/lib/string.in.h
index c0c1a54f39d..7d83668f6ec 100644
--- a/lib/string.in.h
+++ b/lib/string.in.h
@@ -123,6 +123,12 @@ _GL_WARN_ON_USE (ffsll, "ffsll is not portable - use the ffsll module");
 #endif
 
 
+#if defined _WIN32 && !defined __CYGWIN__
+# undef memccpy
+# define memccpy _memccpy
+#endif
+
+
 /* Return the first instance of C within N bytes of S, or NULL.  */
 #if @GNULIB_MEMCHR@
 # if @REPLACE_MEMCHR@
@@ -384,6 +390,12 @@ _GL_WARN_ON_USE (strchrnul, "strchrnul is unportable - "
 #  endif
 _GL_FUNCDECL_RPL (strdup, char *, (char const *__s) _GL_ARG_NONNULL ((1)));
 _GL_CXXALIAS_RPL (strdup, char *, (char const *__s));
+# elif defined _WIN32 && !defined __CYGWIN__
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef strdup
+#   define strdup _strdup
+#  endif
+_GL_CXXALIAS_MDA (strdup, char *, (char const *__s));
 # else
 #  if defined __cplusplus && defined GNULIB_NAMESPACE && defined strdup
     /* strdup exists as a function and as a macro.  Get rid of the macro.  */
@@ -401,6 +413,9 @@ _GL_CXXALIASWARN (strdup);
 _GL_WARN_ON_USE (strdup, "strdup is unportable - "
                  "use gnulib module strdup for portability");
 # endif
+#elif defined _WIN32 && !defined __CYGWIN__
+# undef strdup
+# define strdup _strdup
 #endif
 
 /* Append no more than N characters from SRC onto DEST.  */
diff --git a/lib/sys_select.in.h b/lib/sys_select.in.h
index 7a7b157d545..72cb9ba7b0f 100644
--- a/lib/sys_select.in.h
+++ b/lib/sys_select.in.h
@@ -177,14 +177,14 @@ rpl_fd_isset (SOCKET fd, fd_set * set)
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 #   undef close
 #   define close close_used_without_including_unistd_h
-#  else
+#  elif !defined __clang__
     _GL_WARN_ON_USE (close,
                      "close() used without including <unistd.h>");
 #  endif
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 #   undef gethostname
 #   define gethostname gethostname_used_without_including_unistd_h
-#  else
+#  elif !defined __clang__
     _GL_WARN_ON_USE (gethostname,
                      "gethostname() used without including <unistd.h>");
 #  endif
@@ -219,7 +219,7 @@ rpl_fd_isset (SOCKET fd, fd_set * set)
 #   define setsockopt          setsockopt_used_without_including_sys_socket_h
 #   undef shutdown
 #   define shutdown            shutdown_used_without_including_sys_socket_h
-#  else
+#  elif !defined __clang__
     _GL_WARN_ON_USE (socket,
                      "socket() used without including <sys/socket.h>");
     _GL_WARN_ON_USE (connect,
diff --git a/lib/sys_stat.in.h b/lib/sys_stat.in.h
index 89e167f6d1c..3e0e4b27b7e 100644
--- a/lib/sys_stat.in.h
+++ b/lib/sys_stat.in.h
@@ -391,6 +391,12 @@ struct stat
 #endif
 
 
+#if defined _WIN32 && !defined __CYGWIN__
+# undef chmod
+# define chmod _chmod
+#endif
+
+
 #if @GNULIB_FCHMODAT@
 # if @REPLACE_FCHMODAT@
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
@@ -432,7 +438,9 @@ _GL_CXXALIAS_RPL (fstat, int, (int fd, struct stat *buf));
 # else
 _GL_CXXALIAS_SYS (fstat, int, (int fd, struct stat *buf));
 # endif
+# if __GLIBC__ >= 2
 _GL_CXXALIASWARN (fstat);
+# endif
 #elif @GNULIB_OVERRIDES_STRUCT_STAT@
 # undef fstat
 # define fstat fstat_used_without_requesting_gnulib_module_fstat
@@ -800,6 +808,12 @@ _GL_WARN_ON_USE (stat, "stat is unportable - "
 #endif
 
 
+#if defined _WIN32 && !defined __CYGWIN__
+# undef umask
+# define umask _umask
+#endif
+
+
 #if @GNULIB_UTIMENSAT@
 /* Use the rpl_ prefix also on Solaris <= 9, because on Solaris 9 our utimensat
    implementation relies on futimesat, which on Solaris 10 makes an invocation
diff --git a/lib/sys_time.in.h b/lib/sys_time.in.h
index d30b26719b2..1c12d5f13d7 100644
--- a/lib/sys_time.in.h
+++ b/lib/sys_time.in.h
@@ -135,7 +135,7 @@ _GL_WARN_ON_USE (gettimeofday, "gettimeofday is unportable - "
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 #   undef close
 #   define close close_used_without_including_unistd_h
-#  else
+#  elif !defined __clang__
      _GL_WARN_ON_USE (close,
                       "close() used without including <unistd.h>");
 #  endif
diff --git a/lib/time.in.h b/lib/time.in.h
index 1d11650e77f..32e6ec03ef4 100644
--- a/lib/time.in.h
+++ b/lib/time.in.h
@@ -135,13 +135,19 @@ _GL_CXXALIASWARN (nanosleep);
 #   endif
 _GL_FUNCDECL_RPL (tzset, void, (void));
 _GL_CXXALIAS_RPL (tzset, void, (void));
-#  else
-#   if ! @HAVE_TZSET@
-_GL_FUNCDECL_SYS (tzset, void, (void));
+#  elif defined _WIN32 && !defined __CYGWIN__
+#   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#    undef tzset
+#    define tzset _tzset
 #   endif
+_GL_CXXALIAS_MDA (tzset, void, (void));
+#  else
 _GL_CXXALIAS_SYS (tzset, void, (void));
 #  endif
 _GL_CXXALIASWARN (tzset);
+# elif defined _WIN32 && !defined __CYGWIN__
+#  undef tzset
+#  define tzset _tzset
 # endif
 
 /* Return the 'time_t' representation of TP and normalize TP.  */
diff --git a/lib/time_rz.c b/lib/time_rz.c
index 5d85963c9ed..95438cf876e 100644
--- a/lib/time_rz.c
+++ b/lib/time_rz.c
@@ -54,31 +54,6 @@ enum { ABBR_SIZE_MIN = DEFAULT_MXFAST - offsetof (struct tm_zone, abbrs) };
    matters; the pointer is never dereferenced.  */
 static timezone_t const local_tz = (timezone_t) 1;
 
-#if HAVE_TM_ZONE || HAVE_TZNAME
-
-/* Return true if the values A and B differ according to the rules for
-   tm_isdst: A and B differ if one is zero and the other positive.  */
-static bool
-isdst_differ (int a, int b)
-{
-  return !a != !b && 0 <= a && 0 <= b;
-}
-
-/* Return true if A and B are equal.  */
-static int
-equal_tm (const struct tm *a, const struct tm *b)
-{
-  return ! ((a->tm_sec ^ b->tm_sec)
-            | (a->tm_min ^ b->tm_min)
-            | (a->tm_hour ^ b->tm_hour)
-            | (a->tm_mday ^ b->tm_mday)
-            | (a->tm_mon ^ b->tm_mon)
-            | (a->tm_year ^ b->tm_year)
-            | isdst_differ (a->tm_isdst, b->tm_isdst));
-}
-
-#endif
-
 /* Copy to ABBRS the abbreviation at ABBR with size ABBR_SIZE (this
    includes its trailing null byte).  Append an extra null byte to
    mark the end of ABBRS.  */
@@ -327,17 +302,25 @@ mktime_z (timezone_t tz, struct tm *tm)
       timezone_t old_tz = set_tz (tz);
       if (old_tz)
         {
-          time_t t = mktime (tm);
-#if HAVE_TM_ZONE || HAVE_TZNAME
-          time_t badtime = -1;
           struct tm tm_1;
-          if ((t != badtime
-               || (localtime_r (&t, &tm_1) && equal_tm (tm, &tm_1)))
-              && !save_abbr (tz, tm))
-            t = badtime;
+          tm_1.tm_sec = tm->tm_sec;
+          tm_1.tm_min = tm->tm_min;
+          tm_1.tm_hour = tm->tm_hour;
+          tm_1.tm_mday = tm->tm_mday;
+          tm_1.tm_mon = tm->tm_mon;
+          tm_1.tm_year = tm->tm_year;
+          tm_1.tm_yday = -1;
+          tm_1.tm_isdst = tm->tm_isdst;
+          time_t t = mktime (&tm_1);
+          bool ok = 0 <= tm_1.tm_yday;
+#if HAVE_TM_ZONE || HAVE_TZNAME
+          ok = ok && save_abbr (tz, &tm_1);
 #endif
-          if (revert_tz (old_tz))
-            return t;
+          if (revert_tz (old_tz) && ok)
+            {
+              *tm = tm_1;
+              return t;
+            }
         }
       return -1;
     }
diff --git a/lib/unistd.in.h b/lib/unistd.in.h
index a81a14fe873..357a35e3881 100644
--- a/lib/unistd.in.h
+++ b/lib/unistd.in.h
@@ -273,6 +273,12 @@ _GL_INLINE_HEADER_BEGIN
 _GL_FUNCDECL_RPL (access, int, (const char *file, int mode)
                                _GL_ARG_NONNULL ((1)));
 _GL_CXXALIAS_RPL (access, int, (const char *file, int mode));
+# elif defined _WIN32 && !defined __CYGWIN__
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef access
+#   define access _access
+#  endif
+_GL_CXXALIAS_MDA (access, int, (const char *file, int mode));
 # else
 _GL_CXXALIAS_SYS (access, int, (const char *file, int mode));
 # endif
@@ -286,11 +292,22 @@ _GL_WARN_ON_USE (access, "access does not always support X_OK - "
                  "also, this function is a security risk - "
                  "use the gnulib module faccessat instead");
 # endif
+#elif defined _WIN32 && !defined __CYGWIN__
+# undef access
+# define access _access
 #endif
 
 
 #if @GNULIB_CHDIR@
+# if defined _WIN32 && !defined __CYGWIN__
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef chdir
+#   define chdir _chdir
+#  endif
+_GL_CXXALIAS_MDA (chdir, int, (const char *file));
+# else
 _GL_CXXALIAS_SYS (chdir, int, (const char *file) _GL_ARG_NONNULL ((1)));
+# endif
 _GL_CXXALIASWARN (chdir);
 #elif defined GNULIB_POSIXCHECK
 # undef chdir
@@ -298,6 +315,9 @@ _GL_CXXALIASWARN (chdir);
 _GL_WARN_ON_USE (chown, "chdir is not always in <unistd.h> - "
                  "use gnulib module chdir for portability");
 # endif
+#elif defined _WIN32 && !defined __CYGWIN__
+# undef chdir
+# define chdir _chdir
 #endif
 
 
@@ -342,6 +362,12 @@ _GL_WARN_ON_USE (chown, "chown fails to follow symlinks on some systems and "
 #  endif
 _GL_FUNCDECL_RPL (close, int, (int fd));
 _GL_CXXALIAS_RPL (close, int, (int fd));
+# elif defined _WIN32 && !defined __CYGWIN__
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef close
+#   define close _close
+#  endif
+_GL_CXXALIAS_MDA (close, int, (int fd));
 # else
 _GL_CXXALIAS_SYS (close, int, (int fd));
 # endif
@@ -354,6 +380,9 @@ _GL_CXXALIASWARN (close);
 /* Assume close is always declared.  */
 _GL_WARN_ON_USE (close, "close does not portably work on sockets - "
                  "use gnulib module close for portability");
+#elif defined _WIN32 && !defined __CYGWIN__
+# undef close
+# define close _close
 #endif
 
 
@@ -382,6 +411,12 @@ _GL_WARN_ON_USE (copy_file_range,
 #  endif
 _GL_FUNCDECL_RPL (dup, int, (int oldfd));
 _GL_CXXALIAS_RPL (dup, int, (int oldfd));
+# elif defined _WIN32 && !defined __CYGWIN__
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef dup
+#   define dup _dup
+#  endif
+_GL_CXXALIAS_MDA (dup, int, (int oldfd));
 # else
 _GL_CXXALIAS_SYS (dup, int, (int oldfd));
 # endif
@@ -392,6 +427,9 @@ _GL_CXXALIASWARN (dup);
 _GL_WARN_ON_USE (dup, "dup is unportable - "
                  "use gnulib module dup for portability");
 # endif
+#elif defined _WIN32 && !defined __CYGWIN__
+# undef dup
+# define dup _dup
 #endif
 
 
@@ -407,6 +445,12 @@ _GL_WARN_ON_USE (dup, "dup is unportable - "
 #  endif
 _GL_FUNCDECL_RPL (dup2, int, (int oldfd, int newfd));
 _GL_CXXALIAS_RPL (dup2, int, (int oldfd, int newfd));
+# elif defined _WIN32 && !defined __CYGWIN__
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef dup2
+#   define dup2 _dup2
+#  endif
+_GL_CXXALIAS_MDA (dup2, int, (int oldfd, int newfd));
 # else
 _GL_CXXALIAS_SYS (dup2, int, (int oldfd, int newfd));
 # endif
@@ -417,6 +461,9 @@ _GL_CXXALIASWARN (dup2);
 _GL_WARN_ON_USE (dup2, "dup2 is unportable - "
                  "use gnulib module dup2 for portability");
 # endif
+#elif defined _WIN32 && !defined __CYGWIN__
+# undef dup2
+# define dup2 _dup2
 #endif
 
 
@@ -517,6 +564,43 @@ _GL_WARN_ON_USE (euidaccess, "euidaccess is unportable - "
 #endif
 
 
+#if defined _WIN32 && !defined __CYGWIN__
+# undef execl
+# define execl _execl
+#endif
+
+#if defined _WIN32 && !defined __CYGWIN__
+# undef execle
+# define execle _execle
+#endif
+
+#if defined _WIN32 && !defined __CYGWIN__
+# undef execlp
+# define execlp _execlp
+#endif
+
+
+#if defined _WIN32 && !defined __CYGWIN__
+# undef execv
+# define execv _execv
+#endif
+
+#if defined _WIN32 && !defined __CYGWIN__
+# undef execve
+# define execve _execve
+#endif
+
+#if defined _WIN32 && !defined __CYGWIN__
+# undef execvp
+# define execvp _execvp
+#endif
+
+#if defined _WIN32 && !defined __CYGWIN__
+# undef execvpe
+# define execvpe _execvpe
+#endif
+
+
 #if @GNULIB_FACCESSAT@
 # if @REPLACE_FACCESSAT@
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
@@ -692,6 +776,12 @@ _GL_WARN_ON_USE (ftruncate, "ftruncate is unportable - "
 #  endif
 _GL_FUNCDECL_RPL (getcwd, char *, (char *buf, size_t size));
 _GL_CXXALIAS_RPL (getcwd, char *, (char *buf, size_t size));
+# elif defined _WIN32 && !defined __CYGWIN__
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef getcwd
+#   define getcwd _getcwd
+#  endif
+_GL_CXXALIAS_MDA (getcwd, char *, (char *buf, size_t size));
 # else
 /* Need to cast, because on mingw, the second parameter is
                                                    int size.  */
@@ -704,6 +794,9 @@ _GL_CXXALIASWARN (getcwd);
 _GL_WARN_ON_USE (getcwd, "getcwd is unportable - "
                  "use gnulib module getcwd for portability");
 # endif
+#elif defined _WIN32 && !defined __CYGWIN__
+# undef getcwd
+# define getcwd _getcwd
 #endif
 
 
@@ -1038,6 +1131,12 @@ _GL_WARN_ON_USE (getpass, "getpass is unportable - "
 #endif
 
 
+#if defined _WIN32 && !defined __CYGWIN__
+# undef getpid
+# define getpid _getpid
+#endif
+
+
 #if @GNULIB_GETUSERSHELL@
 /* Return the next valid login shell on the system, or NULL when the end of
    the list has been reached.  */
@@ -1110,6 +1209,12 @@ _GL_WARN_ON_USE (group_member, "group_member is unportable - "
 #  endif
 _GL_FUNCDECL_RPL (isatty, int, (int fd));
 _GL_CXXALIAS_RPL (isatty, int, (int fd));
+# elif defined _WIN32 && !defined __CYGWIN__
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef isatty
+#   define isatty _isatty
+#  endif
+_GL_CXXALIAS_MDA (isatty, int, (int fd));
 # else
 _GL_CXXALIAS_SYS (isatty, int, (int fd));
 # endif
@@ -1120,6 +1225,9 @@ _GL_CXXALIASWARN (isatty);
 _GL_WARN_ON_USE (isatty, "isatty has portability problems on native Windows - "
                  "use gnulib module isatty for portability");
 # endif
+#elif defined _WIN32 && !defined __CYGWIN__
+# undef isatty
+# define isatty _isatty
 #endif
 
 
@@ -1231,6 +1339,12 @@ _GL_WARN_ON_USE (linkat, "linkat is unportable - "
 #  endif
 _GL_FUNCDECL_RPL (lseek, off_t, (int fd, off_t offset, int whence));
 _GL_CXXALIAS_RPL (lseek, off_t, (int fd, off_t offset, int whence));
+# elif defined _WIN32 && !defined __CYGWIN__
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef lseek
+#   define lseek _lseek
+#  endif
+_GL_CXXALIAS_MDA (lseek, off_t, (int fd, off_t offset, int whence));
 # else
 _GL_CXXALIAS_SYS (lseek, off_t, (int fd, off_t offset, int whence));
 # endif
@@ -1241,6 +1355,9 @@ _GL_CXXALIASWARN (lseek);
 _GL_WARN_ON_USE (lseek, "lseek does not fail with ESPIPE on pipes on some "
                  "systems - use gnulib module lseek for portability");
 # endif
+#elif defined _WIN32 && !defined __CYGWIN__
+# undef lseek
+# define lseek _lseek
 #endif
 
 
@@ -1373,6 +1490,12 @@ _GL_WARN_ON_USE (pwrite, "pwrite is unportable - "
 _GL_FUNCDECL_RPL (read, ssize_t, (int fd, void *buf, size_t count)
                                  _GL_ARG_NONNULL ((2)));
 _GL_CXXALIAS_RPL (read, ssize_t, (int fd, void *buf, size_t count));
+# elif defined _WIN32 && !defined __CYGWIN__
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef read
+#   define read _read
+#  endif
+_GL_CXXALIAS_MDA (read, ssize_t, (int fd, void *buf, size_t count));
 # else
 /* Need to cast, because on mingw, the third parameter is
                                                           unsigned int count
@@ -1380,6 +1503,9 @@ _GL_CXXALIAS_RPL (read, ssize_t, (int fd, void *buf, size_t count));
 _GL_CXXALIAS_SYS_CAST (read, ssize_t, (int fd, void *buf, size_t count));
 # endif
 _GL_CXXALIASWARN (read);
+#elif defined _WIN32 && !defined __CYGWIN__
+# undef read
+# define read _read
 #endif
 
 
@@ -1462,6 +1588,12 @@ _GL_WARN_ON_USE (readlinkat, "readlinkat is not portable - "
 #  endif
 _GL_FUNCDECL_RPL (rmdir, int, (char const *name) _GL_ARG_NONNULL ((1)));
 _GL_CXXALIAS_RPL (rmdir, int, (char const *name));
+# elif defined _WIN32 && !defined __CYGWIN__
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef rmdir
+#   define rmdir _rmdir
+#  endif
+_GL_CXXALIAS_MDA (rmdir, int, (char const *name));
 # else
 _GL_CXXALIAS_SYS (rmdir, int, (char const *name));
 # endif
@@ -1472,6 +1604,9 @@ _GL_CXXALIASWARN (rmdir);
 _GL_WARN_ON_USE (rmdir, "rmdir is unportable - "
                  "use gnulib module rmdir for portability");
 # endif
+#elif defined _WIN32 && !defined __CYGWIN__
+# undef rmdir
+# define rmdir _rmdir
 #endif
 
 
@@ -1530,6 +1665,12 @@ _GL_WARN_ON_USE (sleep, "sleep is unportable - "
 #endif
 
 
+#if defined _WIN32 && !defined __CYGWIN__
+# undef swab
+# define swab _swab
+#endif
+
+
 #if @GNULIB_SYMLINK@
 # if @REPLACE_SYMLINK@
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
@@ -1654,6 +1795,12 @@ _GL_WARN_ON_USE (ttyname_r, "ttyname_r is not portable - "
 #  endif
 _GL_FUNCDECL_RPL (unlink, int, (char const *file) _GL_ARG_NONNULL ((1)));
 _GL_CXXALIAS_RPL (unlink, int, (char const *file));
+# elif defined _WIN32 && !defined __CYGWIN__
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef unlink
+#   define unlink _unlink
+#  endif
+_GL_CXXALIAS_MDA (unlink, int, (char const *file));
 # else
 _GL_CXXALIAS_SYS (unlink, int, (char const *file));
 # endif
@@ -1664,6 +1811,9 @@ _GL_CXXALIASWARN (unlink);
 _GL_WARN_ON_USE (unlink, "unlink is not portable - "
                  "use gnulib module unlink for portability");
 # endif
+#elif defined _WIN32 && !defined __CYGWIN__
+# undef unlink
+# define unlink _unlink
 #endif
 
 
@@ -1735,6 +1885,12 @@ _GL_WARN_ON_USE (usleep, "usleep is unportable - "
 _GL_FUNCDECL_RPL (write, ssize_t, (int fd, const void *buf, size_t count)
                                   _GL_ARG_NONNULL ((2)));
 _GL_CXXALIAS_RPL (write, ssize_t, (int fd, const void *buf, size_t count));
+# elif defined _WIN32 && !defined __CYGWIN__
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef write
+#   define write _write
+#  endif
+_GL_CXXALIAS_MDA (write, ssize_t, (int fd, const void *buf, size_t count));
 # else
 /* Need to cast, because on mingw, the third parameter is
                                                              unsigned int count
@@ -1742,6 +1898,9 @@ _GL_CXXALIAS_RPL (write, ssize_t, (int fd, const void *buf, size_t count));
 _GL_CXXALIAS_SYS_CAST (write, ssize_t, (int fd, const void *buf, size_t count));
 # endif
 _GL_CXXALIASWARN (write);
+#elif defined _WIN32 && !defined __CYGWIN__
+# undef write
+# define write _write
 #endif
 
 _GL_INLINE_HEADER_END
diff --git a/lib/verify.h b/lib/verify.h
index 58172f3cb7f..0ba8d579071 100644
--- a/lib/verify.h
+++ b/lib/verify.h
@@ -23,11 +23,15 @@
 
 /* Define _GL_HAVE__STATIC_ASSERT to 1 if _Static_assert (R, DIAGNOSTIC)
    works as per C11.  This is supported by GCC 4.6.0 and later, in C
-   mode.
+   mode, and by clang (also in C++ mode).
 
    Define _GL_HAVE__STATIC_ASSERT1 to 1 if _Static_assert (R) works as
-   per C2X, and define _GL_HAVE_STATIC_ASSERT1 if static_assert (R)
-   works as per C++17.  This is supported by GCC 9.1 and later.
+   per C2X.  This is supported by GCC 9.1 and later, and by clang in
+   C++1z mode.
+
+   Define _GL_HAVE_STATIC_ASSERT1 if static_assert (R) works as per
+   C++17.  This is supported by GCC 9.1 and later, and by clang in
+   C++1z mode.
 
    Support compilers claiming conformance to the relevant standard,
    and also support GCC when not pedantic.  If we were willing to slow
@@ -35,7 +39,8 @@
    since this affects only the quality of diagnostics, why bother?  */
 #ifndef __cplusplus
 # if (201112L <= __STDC_VERSION__ \
-      || (!defined __STRICT_ANSI__ && 4 < __GNUC__ + (6 <= __GNUC_MINOR__)))
+      || (!defined __STRICT_ANSI__ \
+          && (4 < __GNUC__ + (6 <= __GNUC_MINOR__) || 4 <= __clang_major__)))
 #  define _GL_HAVE__STATIC_ASSERT 1
 # endif
 # if (202000L <= __STDC_VERSION__ \
@@ -43,7 +48,15 @@
 #  define _GL_HAVE__STATIC_ASSERT1 1
 # endif
 #else
-# if 201703L <= __cplusplus || 9 <= __GNUC__
+# if 4 <= __clang_major__
+#  define _GL_HAVE__STATIC_ASSERT 1
+# endif
+# if 4 <= __clang_major__ && 201411 <= __cpp_static_assert
+#  define _GL_HAVE__STATIC_ASSERT1 1
+# endif
+# if 201703L <= __cplusplus \
+     || 9 <= __GNUC__ \
+     || (4 <= __clang_major__ && 201411 <= __cpp_static_assert)
 #  define _GL_HAVE_STATIC_ASSERT1 1
 # endif
 #endif