Update from Gnulib

This is minor refactoring that should not affect Emacs builds.
It incorporates:
2018-10-12 Make better use of Autoconf
* m4/environ.m4, m4/fsusage.m4, m4/manywarnings.m4, m4/socklen.m4:
Copy from Gnulib.

4 files changed, 234 insertions, 232 deletions

diff --git a/m4/environ.m4 b/m4/environ.m4
index 68b67eaca4e..acee5364b77 100644
--- a/m4/environ.m4
+++ b/m4/environ.m4
@@ -1,4 +1,4 @@
-# environ.m4 serial 6
+# environ.m4 serial 7
 dnl Copyright (C) 2001-2004, 2006-2018 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -29,16 +29,14 @@ AC_DEFUN_ONCE([gl_ENVIRON],
 AC_DEFUN([gt_CHECK_VAR_DECL],
 [
   define([gt_cv_var], [gt_cv_var_]$2[_declaration])
-  AC_MSG_CHECKING([if $2 is properly declared])
-  AC_CACHE_VAL([gt_cv_var], [
-    AC_COMPILE_IFELSE(
-      [AC_LANG_PROGRAM(
-         [[$1
-           extern struct { int foo; } $2;]],
-         [[$2.foo = 1;]])],
-      [gt_cv_var=no],
-      [gt_cv_var=yes])])
-  AC_MSG_RESULT([$gt_cv_var])
+  AC_CACHE_CHECK([if $2 is properly declared], [gt_cv_var],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[$1
+            extern struct { int foo; } $2;]],
+          [[$2.foo = 1;]])],
+       [gt_cv_var=no],
+       [gt_cv_var=yes])])
   if test $gt_cv_var = yes; then
     AC_DEFINE([HAVE_]m4_translit($2, [a-z], [A-Z])[_DECL], 1,
               [Define if you have the declaration of $2.])
diff --git a/m4/fsusage.m4 b/m4/fsusage.m4
index f9dfbcb7a04..aab4024a975 100644
--- a/m4/fsusage.m4
+++ b/m4/fsusage.m4
@@ -1,4 +1,4 @@
-# serial 32
+# serial 33
 # Obtaining file system usage information.
 
 # Copyright (C) 1997-1998, 2000-2001, 2003-2018 Free Software Foundation, Inc.
@@ -29,27 +29,30 @@ AC_DEFUN([gl_FSUSAGE],
 
 AC_DEFUN([gl_FILE_SYSTEM_USAGE],
 [
-dnl Enable large-file support. This has the effect of changing the size
-dnl of field f_blocks in 'struct statvfs' from 32 bit to 64 bit on
-dnl glibc/Hurd, HP-UX 11, Solaris (32-bit mode). It also changes the size
-dnl of field f_blocks in 'struct statfs' from 32 bit to 64 bit on
-dnl Mac OS X >= 10.5 (32-bit mode).
-AC_REQUIRE([AC_SYS_LARGEFILE])
+  dnl Enable large-file support. This has the effect of changing the size
+  dnl of field f_blocks in 'struct statvfs' from 32 bit to 64 bit on
+  dnl glibc/Hurd, HP-UX 11, Solaris (32-bit mode). It also changes the size
+  dnl of field f_blocks in 'struct statfs' from 32 bit to 64 bit on
+  dnl Mac OS X >= 10.5 (32-bit mode).
+  AC_REQUIRE([AC_SYS_LARGEFILE])
 
-AC_MSG_CHECKING([how to get file system space usage])
-ac_fsusage_space=no
+  AC_MSG_CHECKING([how to get file system space usage])
+  ac_fsusage_space=no
 
-# Perform only the link test since it seems there are no variants of the
-# statvfs function.  This check is more than just AC_CHECK_FUNCS([statvfs])
-# because that got a false positive on SCO OSR5.  Adding the declaration
-# of a 'struct statvfs' causes this test to fail (as it should) on such
-# systems.  That system is reported to work fine with STAT_STATFS4 which
-# is what it gets when this test fails.
-if test $ac_fsusage_space = no; then
-  # glibc/{Hurd,kFreeBSD}, FreeBSD >= 5.0, NetBSD >= 3.0,
-  # OpenBSD >= 4.4, AIX, HP-UX, IRIX, Solaris, Cygwin, Interix, BeOS.
-  AC_CACHE_CHECK([for statvfs function (SVR4)], [fu_cv_sys_stat_statvfs],
-                 [AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <sys/types.h>
+  # Perform only the link test since it seems there are no variants of the
+  # statvfs function.  This check is more than just AC_CHECK_FUNCS([statvfs])
+  # because that got a false positive on SCO OSR5.  Adding the declaration
+  # of a 'struct statvfs' causes this test to fail (as it should) on such
+  # systems.  That system is reported to work fine with STAT_STATFS4 which
+  # is what it gets when this test fails.
+  if test $ac_fsusage_space = no; then
+    # glibc/{Hurd,kFreeBSD}, FreeBSD >= 5.0, NetBSD >= 3.0,
+    # OpenBSD >= 4.4, AIX, HP-UX, IRIX, Solaris, Cygwin, Interix, BeOS.
+    AC_CACHE_CHECK([for statvfs function (SVR4)],
+      [fu_cv_sys_stat_statvfs],
+      [AC_LINK_IFELSE(
+         [AC_LANG_PROGRAM([[
+#include <sys/types.h>
 #ifdef __osf__
 "Do not use Tru64's statvfs implementation"
 #endif
@@ -68,45 +71,47 @@ struct statvfs fsd;
 int check_f_blocks_size[sizeof fsd.f_blocks * CHAR_BIT <= 32 ? -1 : 1];
 #endif
 ]],
-                                    [[statvfs (0, &fsd);]])],
-                                 [fu_cv_sys_stat_statvfs=yes],
-                                 [fu_cv_sys_stat_statvfs=no])])
-  if test $fu_cv_sys_stat_statvfs = yes; then
-    ac_fsusage_space=yes
-    # AIX >= 5.2 has statvfs64 that has a wider f_blocks field than statvfs.
-    # glibc, HP-UX, IRIX, Solaris have statvfs64 as well, but on these systems
-    # statvfs with large-file support is already equivalent to statvfs64.
-    AC_CACHE_CHECK([whether to use statvfs64],
-      [fu_cv_sys_stat_statvfs64],
-      [AC_LINK_IFELSE(
-         [AC_LANG_PROGRAM(
-            [[#include <sys/types.h>
-              #include <sys/statvfs.h>
-              struct statvfs64 fsd;
-              int check_f_blocks_larger_in_statvfs64
-                [sizeof (((struct statvfs64 *) 0)->f_blocks)
-                 > sizeof (((struct statvfs *) 0)->f_blocks)
-                 ? 1 : -1];
-            ]],
-            [[statvfs64 (0, &fsd);]])],
-         [fu_cv_sys_stat_statvfs64=yes],
-         [fu_cv_sys_stat_statvfs64=no])
+            [[statvfs (0, &fsd);]])],
+         [fu_cv_sys_stat_statvfs=yes],
+         [fu_cv_sys_stat_statvfs=no])
       ])
-    if test $fu_cv_sys_stat_statvfs64 = yes; then
-      AC_DEFINE([STAT_STATVFS64], [1],
-                [  Define if statvfs64 should be preferred over statvfs.])
-    else
-      AC_DEFINE([STAT_STATVFS], [1],
-                [  Define if there is a function named statvfs.  (SVR4)])
+    if test $fu_cv_sys_stat_statvfs = yes; then
+      ac_fsusage_space=yes
+      # AIX >= 5.2 has statvfs64 that has a wider f_blocks field than statvfs.
+      # glibc, HP-UX, IRIX, Solaris have statvfs64 as well, but on these systems
+      # statvfs with large-file support is already equivalent to statvfs64.
+      AC_CACHE_CHECK([whether to use statvfs64],
+        [fu_cv_sys_stat_statvfs64],
+        [AC_LINK_IFELSE(
+           [AC_LANG_PROGRAM(
+              [[#include <sys/types.h>
+                #include <sys/statvfs.h>
+                struct statvfs64 fsd;
+                int check_f_blocks_larger_in_statvfs64
+                  [sizeof (((struct statvfs64 *) 0)->f_blocks)
+                   > sizeof (((struct statvfs *) 0)->f_blocks)
+                   ? 1 : -1];
+              ]],
+              [[statvfs64 (0, &fsd);]])],
+           [fu_cv_sys_stat_statvfs64=yes],
+           [fu_cv_sys_stat_statvfs64=no])
+        ])
+      if test $fu_cv_sys_stat_statvfs64 = yes; then
+        AC_DEFINE([STAT_STATVFS64], [1],
+          [Define if statvfs64 should be preferred over statvfs.])
+      else
+        AC_DEFINE([STAT_STATVFS], [1],
+          [Define if there is a function named statvfs.  (SVR4)])
+      fi
     fi
   fi
-fi
 
-# Check for this unconditionally so we have a
-# good fallback on glibc/Linux > 2.6 < 2.6.36
-AC_MSG_CHECKING([for two-argument statfs with statfs.f_frsize member])
-AC_CACHE_VAL([fu_cv_sys_stat_statfs2_frsize],
-[AC_RUN_IFELSE([AC_LANG_SOURCE([[
+  # Check for this unconditionally so we have a
+  # good fallback on glibc/Linux > 2.6 < 2.6.36
+  AC_CACHE_CHECK([for two-argument statfs with statfs.f_frsize member],
+    [fu_cv_sys_stat_statfs2_frsize],
+    [AC_RUN_IFELSE(
+       [AC_LANG_SOURCE([[
 #ifdef HAVE_SYS_PARAM_H
 #include <sys/param.h>
 #endif
@@ -119,26 +124,26 @@ AC_CACHE_VAL([fu_cv_sys_stat_statfs2_frsize],
   int
   main ()
   {
-  struct statfs fsd;
-  fsd.f_frsize = 0;
-  return statfs (".", &fsd) != 0;
+    struct statfs fsd;
+    fsd.f_frsize = 0;
+    return statfs (".", &fsd) != 0;
   }]])],
-  [fu_cv_sys_stat_statfs2_frsize=yes],
-  [fu_cv_sys_stat_statfs2_frsize=no],
-  [fu_cv_sys_stat_statfs2_frsize=no])])
-AC_MSG_RESULT([$fu_cv_sys_stat_statfs2_frsize])
-if test $fu_cv_sys_stat_statfs2_frsize = yes; then
+       [fu_cv_sys_stat_statfs2_frsize=yes],
+       [fu_cv_sys_stat_statfs2_frsize=no],
+       [fu_cv_sys_stat_statfs2_frsize=no])
+    ])
+  if test $fu_cv_sys_stat_statfs2_frsize = yes; then
     ac_fsusage_space=yes
     AC_DEFINE([STAT_STATFS2_FRSIZE], [1],
-[  Define if statfs takes 2 args and struct statfs has a field named f_frsize.
-   (glibc/Linux > 2.6)])
-fi
+      [Define if statfs takes 2 args and struct statfs has a field named f_frsize.
+       (glibc/Linux > 2.6)])
+  fi
 
-if test $ac_fsusage_space = no; then
-  # DEC Alpha running OSF/1
-  AC_MSG_CHECKING([for 3-argument statfs function (DEC OSF/1)])
-  AC_CACHE_VAL([fu_cv_sys_stat_statfs3_osf1],
-  [AC_RUN_IFELSE([AC_LANG_SOURCE([[
+  if test $ac_fsusage_space = no; then
+    # DEC Alpha running OSF/1
+    AC_CACHE_CHECK([for 3-argument statfs function (DEC OSF/1)],
+      [fu_cv_sys_stat_statfs3_osf1],
+      [AC_RUN_IFELSE([AC_LANG_SOURCE([[
 #include <sys/param.h>
 #include <sys/types.h>
 #include <sys/mount.h>
@@ -149,28 +154,27 @@ if test $ac_fsusage_space = no; then
     fsd.f_fsize = 0;
     return statfs (".", &fsd, sizeof (struct statfs)) != 0;
   }]])],
-    [fu_cv_sys_stat_statfs3_osf1=yes],
-    [fu_cv_sys_stat_statfs3_osf1=no],
-    [fu_cv_sys_stat_statfs3_osf1=no])])
-  AC_MSG_RESULT([$fu_cv_sys_stat_statfs3_osf1])
-  if test $fu_cv_sys_stat_statfs3_osf1 = yes; then
-    ac_fsusage_space=yes
-    AC_DEFINE([STAT_STATFS3_OSF1], [1],
-              [   Define if  statfs takes 3 args.  (DEC Alpha running OSF/1)])
+         [fu_cv_sys_stat_statfs3_osf1=yes],
+         [fu_cv_sys_stat_statfs3_osf1=no],
+         [fu_cv_sys_stat_statfs3_osf1=no])
+      ])
+    if test $fu_cv_sys_stat_statfs3_osf1 = yes; then
+      ac_fsusage_space=yes
+      AC_DEFINE([STAT_STATFS3_OSF1], [1],
+        [Define if statfs takes 3 args.  (DEC Alpha running OSF/1)])
+    fi
   fi
-fi
 
-if test $ac_fsusage_space = no; then
-  # glibc/Linux, Mac OS X, FreeBSD < 5.0, NetBSD < 3.0, OpenBSD < 4.4.
-  # (glibc/{Hurd,kFreeBSD}, FreeBSD >= 5.0, NetBSD >= 3.0,
-  # OpenBSD >= 4.4, AIX, HP-UX, OSF/1, Cygwin already handled above.)
-  # (On IRIX you need to include <sys/statfs.h>, not only <sys/mount.h> and
-  # <sys/vfs.h>.)
-  # (On Solaris, statfs has 4 arguments.)
-  AC_MSG_CHECKING([for two-argument statfs with statfs.f_bsize dnl
-member (AIX, 4.3BSD)])
-  AC_CACHE_VAL([fu_cv_sys_stat_statfs2_bsize],
-  [AC_RUN_IFELSE([AC_LANG_SOURCE([[
+  if test $ac_fsusage_space = no; then
+    # glibc/Linux, Mac OS X, FreeBSD < 5.0, NetBSD < 3.0, OpenBSD < 4.4.
+    # (glibc/{Hurd,kFreeBSD}, FreeBSD >= 5.0, NetBSD >= 3.0,
+    # OpenBSD >= 4.4, AIX, HP-UX, OSF/1, Cygwin already handled above.)
+    # (On IRIX you need to include <sys/statfs.h>, not only <sys/mount.h> and
+    # <sys/vfs.h>.)
+    # (On Solaris, statfs has 4 arguments.)
+    AC_CACHE_CHECK([for two-argument statfs with statfs.f_bsize member (AIX, 4.3BSD)],
+      [fu_cv_sys_stat_statfs2_bsize],
+      [AC_RUN_IFELSE([AC_LANG_SOURCE([[
 #ifdef HAVE_SYS_PARAM_H
 #include <sys/param.h>
 #endif
@@ -183,57 +187,56 @@ member (AIX, 4.3BSD)])
   int
   main ()
   {
-  struct statfs fsd;
-  fsd.f_bsize = 0;
-  return statfs (".", &fsd) != 0;
+    struct statfs fsd;
+    fsd.f_bsize = 0;
+    return statfs (".", &fsd) != 0;
   }]])],
-    [fu_cv_sys_stat_statfs2_bsize=yes],
-    [fu_cv_sys_stat_statfs2_bsize=no],
-    [fu_cv_sys_stat_statfs2_bsize=no])])
-  AC_MSG_RESULT([$fu_cv_sys_stat_statfs2_bsize])
-  if test $fu_cv_sys_stat_statfs2_bsize = yes; then
-    ac_fsusage_space=yes
-    AC_DEFINE([STAT_STATFS2_BSIZE], [1],
-[  Define if statfs takes 2 args and struct statfs has a field named f_bsize.
-   (4.3BSD, SunOS 4, HP-UX, AIX PS/2)])
+         [fu_cv_sys_stat_statfs2_bsize=yes],
+         [fu_cv_sys_stat_statfs2_bsize=no],
+         [fu_cv_sys_stat_statfs2_bsize=no])
+      ])
+    if test $fu_cv_sys_stat_statfs2_bsize = yes; then
+      ac_fsusage_space=yes
+      AC_DEFINE([STAT_STATFS2_BSIZE], [1],
+        [Define if statfs takes 2 args and struct statfs has a field named f_bsize.
+         (4.3BSD, SunOS 4, HP-UX, AIX PS/2)])
+    fi
   fi
-fi
 
-if test $ac_fsusage_space = no; then
-  # SVR3
-  # (Solaris already handled above.)
-  AC_MSG_CHECKING([for four-argument statfs (AIX-3.2.5, SVR3)])
-  AC_CACHE_VAL([fu_cv_sys_stat_statfs4],
-  [AC_RUN_IFELSE([AC_LANG_SOURCE([[
+  if test $ac_fsusage_space = no; then
+    # SVR3
+    # (Solaris already handled above.)
+    AC_CACHE_CHECK([for four-argument statfs (AIX-3.2.5, SVR3)],
+      [fu_cv_sys_stat_statfs4],
+      [AC_RUN_IFELSE([AC_LANG_SOURCE([[
 #include <sys/types.h>
 #include <sys/statfs.h>
   int
   main ()
   {
-  struct statfs fsd;
-  return statfs (".", &fsd, sizeof fsd, 0) != 0;
+    struct statfs fsd;
+    return statfs (".", &fsd, sizeof fsd, 0) != 0;
   }]])],
-    [fu_cv_sys_stat_statfs4=yes],
-    [fu_cv_sys_stat_statfs4=no],
-    [fu_cv_sys_stat_statfs4=no])])
-  AC_MSG_RESULT([$fu_cv_sys_stat_statfs4])
-  if test $fu_cv_sys_stat_statfs4 = yes; then
-    ac_fsusage_space=yes
-    AC_DEFINE([STAT_STATFS4], [1],
-      [  Define if statfs takes 4 args.  (SVR3, Dynix, old Irix, old AIX, Dolphin)])
+         [fu_cv_sys_stat_statfs4=yes],
+         [fu_cv_sys_stat_statfs4=no],
+         [fu_cv_sys_stat_statfs4=no])
+      ])
+    if test $fu_cv_sys_stat_statfs4 = yes; then
+      ac_fsusage_space=yes
+      AC_DEFINE([STAT_STATFS4], [1],
+        [Define if statfs takes 4 args.  (SVR3, Dynix, old Irix, old AIX, Dolphin)])
+    fi
   fi
-fi
 
-if test $ac_fsusage_space = no; then
-  # 4.4BSD and older NetBSD
-  # (OSF/1 already handled above.)
-  # (On AIX, you need to include <sys/statfs.h>, not only <sys/mount.h>.)
-  # (On Solaris, statfs has 4 arguments and 'struct statfs' is not declared in
-  # <sys/mount.h>.)
-  AC_MSG_CHECKING([for two-argument statfs with statfs.f_fsize dnl
-member (4.4BSD and NetBSD)])
-  AC_CACHE_VAL([fu_cv_sys_stat_statfs2_fsize],
-  [AC_RUN_IFELSE([AC_LANG_SOURCE([[
+  if test $ac_fsusage_space = no; then
+    # 4.4BSD and older NetBSD
+    # (OSF/1 already handled above.)
+    # (On AIX, you need to include <sys/statfs.h>, not only <sys/mount.h>.)
+    # (On Solaris, statfs has 4 arguments and 'struct statfs' is not declared in
+    # <sys/mount.h>.)
+    AC_CACHE_CHECK([for two-argument statfs with statfs.f_fsize member (4.4BSD and NetBSD)],
+      [fu_cv_sys_stat_statfs2_fsize],
+      [AC_RUN_IFELSE([AC_LANG_SOURCE([[
 #include <sys/types.h>
 #ifdef HAVE_SYS_PARAM_H
 #include <sys/param.h>
@@ -244,27 +247,27 @@ member (4.4BSD and NetBSD)])
   int
   main ()
   {
-  struct statfs fsd;
-  fsd.f_fsize = 0;
-  return statfs (".", &fsd) != 0;
+    struct statfs fsd;
+    fsd.f_fsize = 0;
+    return statfs (".", &fsd) != 0;
   }]])],
-    [fu_cv_sys_stat_statfs2_fsize=yes],
-    [fu_cv_sys_stat_statfs2_fsize=no],
-    [fu_cv_sys_stat_statfs2_fsize=no])])
-  AC_MSG_RESULT([$fu_cv_sys_stat_statfs2_fsize])
-  if test $fu_cv_sys_stat_statfs2_fsize = yes; then
-    ac_fsusage_space=yes
-    AC_DEFINE([STAT_STATFS2_FSIZE], [1],
-[  Define if statfs takes 2 args and struct statfs has a field named f_fsize.
-   (4.4BSD, NetBSD)])
+         [fu_cv_sys_stat_statfs2_fsize=yes],
+         [fu_cv_sys_stat_statfs2_fsize=no],
+         [fu_cv_sys_stat_statfs2_fsize=no])
+      ])
+    if test $fu_cv_sys_stat_statfs2_fsize = yes; then
+      ac_fsusage_space=yes
+      AC_DEFINE([STAT_STATFS2_FSIZE], [1],
+        [Define if statfs takes 2 args and struct statfs has a field named f_fsize.
+         (4.4BSD, NetBSD)])
+    fi
   fi
-fi
 
-if test $ac_fsusage_space = no; then
-  # Ultrix
-  AC_MSG_CHECKING([for two-argument statfs with struct fs_data (Ultrix)])
-  AC_CACHE_VAL([fu_cv_sys_stat_fs_data],
-  [AC_RUN_IFELSE([AC_LANG_SOURCE([[
+  if test $ac_fsusage_space = no; then
+    # Ultrix
+    AC_CACHE_CHECK([for two-argument statfs with struct fs_data (Ultrix)],
+      [fu_cv_sys_stat_fs_data],
+      [AC_RUN_IFELSE([AC_LANG_SOURCE([[
 #include <sys/types.h>
 #ifdef HAVE_SYS_PARAM_H
 #include <sys/param.h>
@@ -278,24 +281,24 @@ if test $ac_fsusage_space = no; then
   int
   main ()
   {
-  struct fs_data fsd;
-  /* Ultrix's statfs returns 1 for success,
-     0 for not mounted, -1 for failure.  */
-  return statfs (".", &fsd) != 1;
+    struct fs_data fsd;
+    /* Ultrix's statfs returns 1 for success,
+       0 for not mounted, -1 for failure.  */
+    return statfs (".", &fsd) != 1;
   }]])],
-    [fu_cv_sys_stat_fs_data=yes],
-    [fu_cv_sys_stat_fs_data=no],
-    [fu_cv_sys_stat_fs_data=no])])
-  AC_MSG_RESULT([$fu_cv_sys_stat_fs_data])
-  if test $fu_cv_sys_stat_fs_data = yes; then
-    ac_fsusage_space=yes
-    AC_DEFINE([STAT_STATFS2_FS_DATA], [1],
-[  Define if statfs takes 2 args and the second argument has
-   type struct fs_data.  (Ultrix)])
+         [fu_cv_sys_stat_fs_data=yes],
+         [fu_cv_sys_stat_fs_data=no],
+         [fu_cv_sys_stat_fs_data=no])
+      ])
+    if test $fu_cv_sys_stat_fs_data = yes; then
+      ac_fsusage_space=yes
+      AC_DEFINE([STAT_STATFS2_FS_DATA], [1],
+        [Define if statfs takes 2 args and the second argument has
+         type struct fs_data.  (Ultrix)])
+    fi
   fi
-fi
 
-AS_IF([test $ac_fsusage_space = yes], [$1], [$2])
+  AS_IF([test $ac_fsusage_space = yes], [$1], [$2])
 
 ])
 
@@ -305,18 +308,22 @@ AS_IF([test $ac_fsusage_space = yes], [$1], [$2])
 # enable the work-around code in fsusage.c.
 AC_DEFUN([gl_STATFS_TRUNCATES],
 [
-  AC_MSG_CHECKING([for statfs that truncates block counts])
-  AC_CACHE_VAL([fu_cv_sys_truncating_statfs],
-  [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+  AC_CACHE_CHECK([for statfs that truncates block counts],
+    [fu_cv_sys_truncating_statfs],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM([[
 #if !defined(sun) && !defined(__sun)
 choke -- this is a workaround for a Sun-specific problem
 #endif
 #include <sys/types.h>
-#include <sys/vfs.h>]],
-      [[struct statfs t; long c = *(t.f_spare);
-        if (c) return 0;]])],
-    [fu_cv_sys_truncating_statfs=yes],
-    [fu_cv_sys_truncating_statfs=no])])
+#include <sys/vfs.h>
+         ]],
+         [[struct statfs t; long c = *(t.f_spare);
+           if (c) return 0;
+         ]])],
+       [fu_cv_sys_truncating_statfs=yes],
+       [fu_cv_sys_truncating_statfs=no])
+    ])
   if test $fu_cv_sys_truncating_statfs = yes; then
     AC_DEFINE([STATFS_TRUNCATES_BLOCK_COUNTS], [1],
       [Define if the block counts reported by statfs may be truncated to 2GB
@@ -324,7 +331,6 @@ choke -- this is a workaround for a Sun-specific problem
        (SunOS 4.1.2, 4.1.3, and 4.1.3_U1 are reported to have this problem.
        SunOS 4.1.1 seems not to be affected.)])
   fi
-  AC_MSG_RESULT([$fu_cv_sys_truncating_statfs])
 ])
 
 
diff --git a/m4/manywarnings.m4 b/m4/manywarnings.m4
index 516c5874765..d831ed2eb60 100644
--- a/m4/manywarnings.m4
+++ b/m4/manywarnings.m4
@@ -1,4 +1,4 @@
-# manywarnings.m4 serial 16
+# manywarnings.m4 serial 17
 dnl Copyright (C) 2008-2018 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -51,54 +51,53 @@ m4_defun([gl_MANYWARN_ALL_GCC(C)],
 
     dnl Check if -W -Werror -Wno-missing-field-initializers is supported
     dnl with the current $CC $CFLAGS $CPPFLAGS.
-    AC_MSG_CHECKING([whether -Wno-missing-field-initializers is supported])
-    AC_CACHE_VAL([gl_cv_cc_nomfi_supported], [
-      gl_save_CFLAGS="$CFLAGS"
-      CFLAGS="$CFLAGS -W -Werror -Wno-missing-field-initializers"
-      AC_COMPILE_IFELSE(
-        [AC_LANG_PROGRAM([[]], [[]])],
-        [gl_cv_cc_nomfi_supported=yes],
-        [gl_cv_cc_nomfi_supported=no])
-      CFLAGS="$gl_save_CFLAGS"])
-    AC_MSG_RESULT([$gl_cv_cc_nomfi_supported])
+    AC_CACHE_CHECK([whether -Wno-missing-field-initializers is supported],
+      [gl_cv_cc_nomfi_supported],
+      [gl_save_CFLAGS="$CFLAGS"
+       CFLAGS="$CFLAGS -W -Werror -Wno-missing-field-initializers"
+       AC_COMPILE_IFELSE(
+         [AC_LANG_PROGRAM([[]], [[]])],
+         [gl_cv_cc_nomfi_supported=yes],
+         [gl_cv_cc_nomfi_supported=no])
+       CFLAGS="$gl_save_CFLAGS"
+      ])
 
     if test "$gl_cv_cc_nomfi_supported" = yes; then
       dnl Now check whether -Wno-missing-field-initializers is needed
       dnl for the { 0, } construct.
-      AC_MSG_CHECKING([whether -Wno-missing-field-initializers is needed])
-      AC_CACHE_VAL([gl_cv_cc_nomfi_needed], [
-        gl_save_CFLAGS="$CFLAGS"
-        CFLAGS="$CFLAGS -W -Werror"
-        AC_COMPILE_IFELSE(
-          [AC_LANG_PROGRAM(
-             [[int f (void)
-               {
-                 typedef struct { int a; int b; } s_t;
-                 s_t s1 = { 0, };
-                 return s1.b;
-               }
-             ]],
-             [[]])],
-          [gl_cv_cc_nomfi_needed=no],
-          [gl_cv_cc_nomfi_needed=yes])
-        CFLAGS="$gl_save_CFLAGS"
-      ])
-      AC_MSG_RESULT([$gl_cv_cc_nomfi_needed])
+      AC_CACHE_CHECK([whether -Wno-missing-field-initializers is needed],
+        [gl_cv_cc_nomfi_needed],
+        [gl_save_CFLAGS="$CFLAGS"
+         CFLAGS="$CFLAGS -W -Werror"
+         AC_COMPILE_IFELSE(
+           [AC_LANG_PROGRAM(
+              [[int f (void)
+                {
+                  typedef struct { int a; int b; } s_t;
+                  s_t s1 = { 0, };
+                  return s1.b;
+                }
+              ]],
+              [[]])],
+           [gl_cv_cc_nomfi_needed=no],
+           [gl_cv_cc_nomfi_needed=yes])
+         CFLAGS="$gl_save_CFLAGS"
+        ])
     fi
 
     dnl Next, check if -Werror -Wuninitialized is useful with the
     dnl user's choice of $CFLAGS; some versions of gcc warn that it
     dnl has no effect if -O is not also used
-    AC_MSG_CHECKING([whether -Wuninitialized is supported])
-    AC_CACHE_VAL([gl_cv_cc_uninitialized_supported], [
-      gl_save_CFLAGS="$CFLAGS"
-      CFLAGS="$CFLAGS -Werror -Wuninitialized"
-      AC_COMPILE_IFELSE(
-        [AC_LANG_PROGRAM([[]], [[]])],
-        [gl_cv_cc_uninitialized_supported=yes],
-        [gl_cv_cc_uninitialized_supported=no])
-      CFLAGS="$gl_save_CFLAGS"])
-    AC_MSG_RESULT([$gl_cv_cc_uninitialized_supported])
+    AC_CACHE_CHECK([whether -Wuninitialized is supported],
+      [gl_cv_cc_uninitialized_supported],
+      [gl_save_CFLAGS="$CFLAGS"
+       CFLAGS="$CFLAGS -Werror -Wuninitialized"
+       AC_COMPILE_IFELSE(
+         [AC_LANG_PROGRAM([[]], [[]])],
+         [gl_cv_cc_uninitialized_supported=yes],
+         [gl_cv_cc_uninitialized_supported=no])
+       CFLAGS="$gl_save_CFLAGS"
+      ])
 
   fi
 
diff --git a/m4/socklen.m4 b/m4/socklen.m4
index f2d996d0eb8..fa79b07b6e4 100644
--- a/m4/socklen.m4
+++ b/m4/socklen.m4
@@ -1,4 +1,4 @@
-# socklen.m4 serial 10
+# socklen.m4 serial 11
 dnl Copyright (C) 2005-2007, 2009-2018 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -15,8 +15,8 @@ dnl So we have to test to find something that will work.
 AC_DEFUN([gl_TYPE_SOCKLEN_T],
   [AC_REQUIRE([gl_CHECK_SOCKET_HEADERS])dnl
    AC_CHECK_TYPE([socklen_t], ,
-     [AC_MSG_CHECKING([for socklen_t equivalent])
-      AC_CACHE_VAL([gl_cv_socklen_t_equiv],
+     [AC_CACHE_CHECK([for socklen_t equivalent],
+        [gl_cv_socklen_t_equiv],
         [# Systems have either "struct sockaddr *" or
          # "void *" as the second argument to getpeername
          gl_cv_socklen_t_equiv=
@@ -34,11 +34,10 @@ AC_DEFUN([gl_TYPE_SOCKLEN_T],
            done
            test "$gl_cv_socklen_t_equiv" != "" && break
          done
-      ])
-      if test "$gl_cv_socklen_t_equiv" = ""; then
-        AC_MSG_ERROR([Cannot find a type to use in place of socklen_t])
-      fi
-      AC_MSG_RESULT([$gl_cv_socklen_t_equiv])
+         if test "$gl_cv_socklen_t_equiv" = ""; then
+           AC_MSG_ERROR([Cannot find a type to use in place of socklen_t])
+         fi
+        ])
       AC_DEFINE_UNQUOTED([socklen_t], [$gl_cv_socklen_t_equiv],
         [type to use in place of socklen_t if not defined])],
      [gl_SOCKET_HEADERS])])