make sure $host and $host_os are defined when used

[Bruno Haible]

The variables 'host' and 'host_os' can be guaranteed to be set only when there
is a preceding invocation of AC_CANONICAL_HOST. So:


2017-07-10  Bruno Haible  <address@hidden>

        Make sure $host and $host_os are defined when used.
        * m4/argz.m4 (gl_FUNC_ARGZ): Require AC_CANONICAL_HOST.
        * m4/closedir.m4 (gl_FUNC_CLOSEDIR): Likewise.
        * m4/csharpexec.m4 (gt_CSHARPEXEC): Likewise.
        * m4/dirfd.m4 (gl_FUNC_DIRFD): Likewise.
        * m4/expl.m4 (gl_FUNC_EXPL): Likewise.
        * m4/ls-mntd-fs.m4 (gl_LIST_MOUNTED_FILE_SYSTEMS): Likewise.
        * m4/lstat.m4 (gl_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK): Likewise.
        * m4/opendir.m4 (gl_FUNC_OPENDIR): Likewise.
        * m4/poll.m4 (gl_FUNC_POLL): Likewise.
        * m4/pselect.m4 (gl_FUNC_PSELECT): Likewise.
        * m4/ptsname.m4 (gl_FUNC_PTSNAME): Likewise.
        * m4/relocatable.m4 (gl_RELOCATABLE_BODY): Likewise.
        * m4/symlinkat.m4 (gl_FUNC_SYMLINKAT): Likewise.
        * m4/ceill.m4 (gl_FUNC_CEILL): Require AC_CANONICAL_HOST outside the
        m4_ifdef block.

diff --git a/m4/argz.m4 b/m4/argz.m4
index 67f4cbe..c34d685 100644
--- a/m4/argz.m4
+++ b/m4/argz.m4
@@ -7,12 +7,13 @@
 # unlimited permission to copy and/or distribute it, with or without
 # modifications, as long as this notice is preserved.
 
-# serial 11 argz.m4
+# serial 12 argz.m4
 
 AC_DEFUN([gl_FUNC_ARGZ],
 [gl_PREREQ_ARGZ
 
 AC_REQUIRE([AC_C_RESTRICT])
+AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
 
 AC_CHECK_HEADERS([argz.h], [], [], [AC_INCLUDES_DEFAULT])
 
diff --git a/m4/ceill.m4 b/m4/ceill.m4
index 8e87acf..e981c7b 100644
--- a/m4/ceill.m4
+++ b/m4/ceill.m4
@@ -1,4 +1,4 @@
-# ceill.m4 serial 14
+# ceill.m4 serial 15
 dnl Copyright (C) 2007, 2009-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -9,6 +9,7 @@ AC_DEFUN([gl_FUNC_CEILL],
   m4_divert_text([DEFAULTS], [gl_ceill_required=plain])
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
   AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
 
   dnl Persuade glibc <math.h> to declare ceill().
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
@@ -25,7 +26,6 @@ AC_DEFUN([gl_FUNC_CEILL],
     fi
     m4_ifdef([gl_FUNC_CEILL_IEEE], [
       if test $gl_ceill_required = ieee && test $REPLACE_CEILL = 0; then
-        AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
         AC_CACHE_CHECK([whether ceill works according to ISO C 99 with IEC 
60559],
           [gl_cv_func_ceill_ieee],
           [
diff --git a/m4/closedir.m4 b/m4/closedir.m4
index 40765b1..69e41b3 100644
--- a/m4/closedir.m4
+++ b/m4/closedir.m4
@@ -1,4 +1,4 @@
-# closedir.m4 serial 5
+# closedir.m4 serial 6
 dnl Copyright (C) 2011-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -7,6 +7,7 @@ dnl with or without modifications, as long as this notice is 
preserved.
 AC_DEFUN([gl_FUNC_CLOSEDIR],
 [
   AC_REQUIRE([gl_DIRENT_H_DEFAULTS])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
 
   AC_CHECK_FUNCS([closedir])
   if test $ac_cv_func_closedir = no; then
diff --git a/m4/csharpexec.m4 b/m4/csharpexec.m4
index 73c2ff4..90b9991 100644
--- a/m4/csharpexec.m4
+++ b/m4/csharpexec.m4
@@ -1,4 +1,4 @@
-# csharpexec.m4 serial 4
+# csharpexec.m4 serial 5
 dnl Copyright (C) 2003-2005, 2009-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -12,6 +12,7 @@ dnl with or without modifications, as long as this notice is 
preserved.
 AC_DEFUN([gt_CSHARPEXEC],
 [
   AC_REQUIRE([gt_CSHARP_CHOICE])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   AC_MSG_CHECKING([for C[#] program execution engine])
   AC_EGREP_CPP([yes], [
 #if defined _WIN32 || defined __WIN32__ || defined __EMX__ || defined __DJGPP__
diff --git a/m4/dirfd.m4 b/m4/dirfd.m4
index b4ec3d1..86c1cb3 100644
--- a/m4/dirfd.m4
+++ b/m4/dirfd.m4
@@ -1,4 +1,4 @@
-# serial 24   -*- Autoconf -*-
+# serial 25   -*- Autoconf -*-
 
 dnl Find out how to get the file descriptor associated with an open DIR*.
 
@@ -12,6 +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
 
   dnl Persuade glibc <dirent.h> to declare dirfd().
   AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
diff --git a/m4/expl.m4 b/m4/expl.m4
index 8ddaad5..530bad8 100644
--- a/m4/expl.m4
+++ b/m4/expl.m4
@@ -1,4 +1,4 @@
-# expl.m4 serial 8
+# expl.m4 serial 9
 dnl Copyright (C) 2010-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -8,6 +8,7 @@ AC_DEFUN([gl_FUNC_EXPL],
 [
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
   AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
 
   dnl Persuade glibc <math.h> to declare expl().
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
diff --git a/m4/ls-mntd-fs.m4 b/m4/ls-mntd-fs.m4
index a678f05..4c8b4ac 100644
--- a/m4/ls-mntd-fs.m4
+++ b/m4/ls-mntd-fs.m4
@@ -1,4 +1,4 @@
-# serial 32
+# serial 33
 # How to list mounted file systems.
 
 # Copyright (C) 1998-2004, 2006, 2009-2017 Free Software Foundation, Inc.
@@ -26,6 +26,7 @@ AC_CHECK_FUNCS([getmntent])
 # gl_LIST_MOUNTED_FILE_SYSTEMS([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
 AC_DEFUN([gl_LIST_MOUNTED_FILE_SYSTEMS],
   [
+AC_REQUIRE([AC_CANONICAL_HOST])
 AC_CHECK_FUNCS([listmntent getmntinfo])
 AC_CHECK_HEADERS_ONCE([sys/param.h sys/statvfs.h])
 
diff --git a/m4/lstat.m4 b/m4/lstat.m4
index 953c117..931f3b2 100644
--- a/m4/lstat.m4
+++ b/m4/lstat.m4
@@ -1,4 +1,4 @@
-# serial 27
+# serial 28
 
 # Copyright (C) 1997-2001, 2003-2017 Free Software Foundation, Inc.
 #
@@ -33,6 +33,7 @@ AC_DEFUN([gl_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK],
 [
   dnl We don't use AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK any more, because it
   dnl is no longer maintained in Autoconf and because it invokes AC_LIBOBJ.
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   AC_CACHE_CHECK([whether lstat correctly handles trailing slash],
     [gl_cv_func_lstat_dereferences_slashed_symlink],
     [rm -f conftest.sym conftest.file
diff --git a/m4/opendir.m4 b/m4/opendir.m4
index b970e65..0047d34 100644
--- a/m4/opendir.m4
+++ b/m4/opendir.m4
@@ -1,4 +1,4 @@
-# opendir.m4 serial 4
+# opendir.m4 serial 5
 dnl Copyright (C) 2011-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -7,6 +7,7 @@ dnl with or without modifications, as long as this notice is 
preserved.
 AC_DEFUN([gl_FUNC_OPENDIR],
 [
   AC_REQUIRE([gl_DIRENT_H_DEFAULTS])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
 
   AC_CHECK_FUNCS([opendir])
   if test $ac_cv_func_opendir = no; then
diff --git a/m4/poll.m4 b/m4/poll.m4
index 5706ab5..060052e 100644
--- a/m4/poll.m4
+++ b/m4/poll.m4
@@ -1,4 +1,4 @@
-# poll.m4 serial 17
+# poll.m4 serial 18
 dnl Copyright (c) 2003, 2005-2007, 2009-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -8,6 +8,7 @@ AC_DEFUN([gl_FUNC_POLL],
 [
   AC_REQUIRE([gl_POLL_H])
   AC_REQUIRE([gl_SOCKETS])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   if test $ac_cv_header_poll_h = no; then
     ac_cv_func_poll=no
     gl_cv_func_poll=no
diff --git a/m4/pselect.m4 b/m4/pselect.m4
index 3f1c43f..ea925cb 100644
--- a/m4/pselect.m4
+++ b/m4/pselect.m4
@@ -1,4 +1,4 @@
-# pselect.m4 serial 2
+# pselect.m4 serial 3
 dnl Copyright (C) 2011-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -8,6 +8,7 @@ AC_DEFUN([gl_FUNC_PSELECT],
 [
   AC_REQUIRE([gl_HEADER_SYS_SELECT])
   AC_REQUIRE([AC_C_RESTRICT])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   AC_CHECK_FUNCS_ONCE([pselect])
 
   if test $ac_cv_func_pselect = yes; then
diff --git a/m4/ptsname.m4 b/m4/ptsname.m4
index 3fd5770..a8fb6c8 100644
--- a/m4/ptsname.m4
+++ b/m4/ptsname.m4
@@ -1,4 +1,4 @@
-# ptsname.m4 serial 3
+# ptsname.m4 serial 4
 dnl Copyright (C) 2010-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -7,6 +7,7 @@ dnl with or without modifications, as long as this notice is 
preserved.
 AC_DEFUN([gl_FUNC_PTSNAME],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
 
   dnl Persuade glibc <stdlib.h> to declare ptsname().
   AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
diff --git a/m4/relocatable.m4 b/m4/relocatable.m4
index a5476e7..6a833ab 100644
--- a/m4/relocatable.m4
+++ b/m4/relocatable.m4
@@ -1,4 +1,4 @@
-# relocatable.m4 serial 18
+# relocatable.m4 serial 19
 dnl Copyright (C) 2003, 2005-2007, 2009-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -31,6 +31,7 @@ AC_DEFUN([gl_RELOCATABLE_BODY],
   AC_BEFORE([AC_PROG_INSTALL],[gl_RELOCATABLE_BODY])
   AC_REQUIRE([AC_LIB_LIBPATH])
   AC_REQUIRE([gl_RELOCATABLE_LIBRARY_BODY])
+  AC_REQUIRE([AC_CANONICAL_HOST])
   is_noop=no
   use_elf_origin_trick=no
   use_wrapper=no
diff --git a/m4/symlinkat.m4 b/m4/symlinkat.m4
index 8d9d417..b1a8a99 100644
--- a/m4/symlinkat.m4
+++ b/m4/symlinkat.m4
@@ -1,4 +1,4 @@
-# serial 6
+# serial 7
 # See if we need to provide symlinkat replacement.
 
 dnl Copyright (C) 2009-2017 Free Software Foundation, Inc.
@@ -10,9 +10,10 @@ dnl with or without modifications, as long as this notice is 
preserved.
 
 AC_DEFUN([gl_FUNC_SYMLINKAT],
 [
-  AC_REQUIRE([gl_FUNC_OPENAT])
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_REQUIRE([gl_FUNC_OPENAT])
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   AC_CHECK_FUNCS_ONCE([symlinkat])
   if test $ac_cv_func_symlinkat = no; then
     HAVE_SYMLINKAT=0