Update from Gnulib

This incorporates:
2020-07-07 dup2: remove support for some very old platforms
2020-07-07 memchr: remove support for some very old platforms
2020-07-04 getumask: new module
2020-07-03 getrandom: fix compilation error on native Windows
2020-07-03 lchmod: simplify after 2020-02-22 change
2020-07-01 manywarnings: improve port to GCC 10.1
2020-06-28 getrandom: fix compilation errors on older versions of mingw
2020-06-29 alloca-opt: fix warning on mingw
* lib/alloca.in.h, lib/dup2.c, lib/getrandom.c, lib/string.in.h:
* lib/sys_stat.in.h, lib/unistd.in.h, m4/dup2.m4, m4/getrandom.m4:
* m4/lchmod.m4, m4/manywarnings.m4, m4/string_h.m4, m4/sys_stat_h.m4:
* m4/unistd_h.m4: Copy from Gnulib.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.

1 files changed, 84 insertions, 97 deletions

diff --git a/m4/dup2.m4 b/m4/dup2.m4
index 21b1ecc26b8..462bfd0e526 100644
--- a/m4/dup2.m4
+++ b/m4/dup2.m4
@@ -1,4 +1,4 @@
-#serial 25
+#serial 26
 dnl Copyright (C) 2002, 2005, 2007, 2009-2020 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -8,107 +8,94 @@ AC_DEFUN([gl_FUNC_DUP2],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
   AC_REQUIRE([AC_CANONICAL_HOST])
-  m4_ifdef([gl_FUNC_DUP2_OBSOLETE], [
-    AC_CHECK_FUNCS_ONCE([dup2])
-    if test $ac_cv_func_dup2 = no; then
-      HAVE_DUP2=0
-    fi
-  ], [
-    AC_DEFINE([HAVE_DUP2], [1], [Define to 1 if you have the 'dup2' function.])
-  ])
-  if test $HAVE_DUP2 = 1; then
-    AC_CACHE_CHECK([whether dup2 works], [gl_cv_func_dup2_works],
-      [AC_RUN_IFELSE([
-         AC_LANG_PROGRAM(
-           [[#include <errno.h>
-             #include <fcntl.h>
-             #include <limits.h>
-             #include <sys/resource.h>
-             #include <unistd.h>
-             #ifndef RLIM_SAVED_CUR
-             # define RLIM_SAVED_CUR RLIM_INFINITY
-             #endif
-             #ifndef RLIM_SAVED_MAX
-             # define RLIM_SAVED_MAX RLIM_INFINITY
-             #endif
-           ]],
-           [[int result = 0;
-             int bad_fd = INT_MAX;
-             struct rlimit rlim;
-             if (getrlimit (RLIMIT_NOFILE, &rlim) == 0
-                 && 0 <= rlim.rlim_cur && rlim.rlim_cur <= INT_MAX
-                 && rlim.rlim_cur != RLIM_INFINITY
-                 && rlim.rlim_cur != RLIM_SAVED_MAX
-                 && rlim.rlim_cur != RLIM_SAVED_CUR)
-               bad_fd = rlim.rlim_cur;
-             #ifdef FD_CLOEXEC
-               if (fcntl (1, F_SETFD, FD_CLOEXEC) == -1)
-                 result |= 1;
-             #endif
-             if (dup2 (1, 1) != 1)
-               result |= 2;
-             #ifdef FD_CLOEXEC
-               if (fcntl (1, F_GETFD) != FD_CLOEXEC)
-                 result |= 4;
-             #endif
-             close (0);
-             if (dup2 (0, 0) != -1)
-               result |= 8;
-             /* Many gnulib modules require POSIX conformance of EBADF.  */
-             if (dup2 (2, bad_fd) == -1 && errno != EBADF)
-               result |= 16;
-             /* Flush out some cygwin core dumps.  */
-             if (dup2 (2, -1) != -1 || errno != EBADF)
-               result |= 32;
-             dup2 (2, 255);
-             dup2 (2, 256);
-             /* On OS/2 kLIBC, dup2() does not work on a directory fd.  */
-             {
-               int fd = open (".", O_RDONLY);
-               if (fd == -1)
-                 result |= 64;
-               else if (dup2 (fd, fd + 1) == -1)
-                 result |= 128;
-
-               close (fd);
-             }
-             return result;]])
-        ],
-        [gl_cv_func_dup2_works=yes], [gl_cv_func_dup2_works=no],
-        [case "$host_os" in
-           mingw*) # on this platform, dup2 always returns 0 for success
-             gl_cv_func_dup2_works="guessing no" ;;
-           cygwin*) # on cygwin 1.5.x, dup2(1,1) returns 0
-             gl_cv_func_dup2_works="guessing no" ;;
-           aix* | freebsd*)
-                   # on AIX 7.1 and FreeBSD 6.1, dup2 (1,toobig) gives EMFILE,
-                   # not EBADF.
-             gl_cv_func_dup2_works="guessing no" ;;
-           haiku*) # on Haiku alpha 2, dup2(1, 1) resets FD_CLOEXEC.
-             gl_cv_func_dup2_works="guessing no" ;;
-           *-android*) # implemented using dup3(), which fails if oldfd == newfd
-             gl_cv_func_dup2_works="guessing no" ;;
-           os2*) # on OS/2 kLIBC, dup2() does not work on a directory fd.
-             gl_cv_func_dup2_works="guessing no" ;;
-           *) gl_cv_func_dup2_works="guessing yes" ;;
-         esac])
-      ])
-    case "$gl_cv_func_dup2_works" in
-      *yes) ;;
-      *)
-        REPLACE_DUP2=1
-        AC_CHECK_FUNCS([setdtablesize])
-        ;;
-    esac
-  fi
+  AC_CACHE_CHECK([whether dup2 works], [gl_cv_func_dup2_works],
+    [AC_RUN_IFELSE([
+       AC_LANG_PROGRAM(
+         [[#include <errno.h>
+           #include <fcntl.h>
+           #include <limits.h>
+           #include <sys/resource.h>
+           #include <unistd.h>
+           #ifndef RLIM_SAVED_CUR
+           # define RLIM_SAVED_CUR RLIM_INFINITY
+           #endif
+           #ifndef RLIM_SAVED_MAX
+           # define RLIM_SAVED_MAX RLIM_INFINITY
+           #endif
+         ]],
+         [[int result = 0;
+           int bad_fd = INT_MAX;
+           struct rlimit rlim;
+           if (getrlimit (RLIMIT_NOFILE, &rlim) == 0
+               && 0 <= rlim.rlim_cur && rlim.rlim_cur <= INT_MAX
+               && rlim.rlim_cur != RLIM_INFINITY
+               && rlim.rlim_cur != RLIM_SAVED_MAX
+               && rlim.rlim_cur != RLIM_SAVED_CUR)
+             bad_fd = rlim.rlim_cur;
+           #ifdef FD_CLOEXEC
+             if (fcntl (1, F_SETFD, FD_CLOEXEC) == -1)
+               result |= 1;
+           #endif
+           if (dup2 (1, 1) != 1)
+             result |= 2;
+           #ifdef FD_CLOEXEC
+             if (fcntl (1, F_GETFD) != FD_CLOEXEC)
+               result |= 4;
+           #endif
+           close (0);
+           if (dup2 (0, 0) != -1)
+             result |= 8;
+           /* Many gnulib modules require POSIX conformance of EBADF.  */
+           if (dup2 (2, bad_fd) == -1 && errno != EBADF)
+             result |= 16;
+           /* Flush out some cygwin core dumps.  */
+           if (dup2 (2, -1) != -1 || errno != EBADF)
+             result |= 32;
+           dup2 (2, 255);
+           dup2 (2, 256);
+           /* On OS/2 kLIBC, dup2() does not work on a directory fd.  */
+           {
+             int fd = open (".", O_RDONLY);
+             if (fd == -1)
+               result |= 64;
+             else if (dup2 (fd, fd + 1) == -1)
+               result |= 128;
+             close (fd);
+           }
+           return result;]])
+      ],
+      [gl_cv_func_dup2_works=yes], [gl_cv_func_dup2_works=no],
+      [case "$host_os" in
+         mingw*) # on this platform, dup2 always returns 0 for success
+           gl_cv_func_dup2_works="guessing no" ;;
+         cygwin*) # on cygwin 1.5.x, dup2(1,1) returns 0
+           gl_cv_func_dup2_works="guessing no" ;;
+         aix* | freebsd*)
+                 # on AIX 7.1 and FreeBSD 6.1, dup2 (1,toobig) gives EMFILE,
+                 # not EBADF.
+           gl_cv_func_dup2_works="guessing no" ;;
+         haiku*) # on Haiku alpha 2, dup2(1, 1) resets FD_CLOEXEC.
+           gl_cv_func_dup2_works="guessing no" ;;
+         *-android*) # implemented using dup3(), which fails if oldfd == newfd
+           gl_cv_func_dup2_works="guessing no" ;;
+         os2*) # on OS/2 kLIBC, dup2() does not work on a directory fd.
+           gl_cv_func_dup2_works="guessing no" ;;
+         *) gl_cv_func_dup2_works="guessing yes" ;;
+       esac])
+    ])
+  case "$gl_cv_func_dup2_works" in
+    *yes) ;;
+    *)
+      REPLACE_DUP2=1
+      AC_CHECK_FUNCS([setdtablesize])
+      ;;
+  esac
   dnl Replace dup2() for supporting the gnulib-defined fchdir() function,
   dnl to keep fchdir's bookkeeping up-to-date.
   m4_ifdef([gl_FUNC_FCHDIR], [
     gl_TEST_FCHDIR
     if test $HAVE_FCHDIR = 0; then
-      if test $HAVE_DUP2 = 1; then
-        REPLACE_DUP2=1
-      fi
+      REPLACE_DUP2=1
     fi
   ])
 ])