Update various GNU configuration scripts to latest versions

See #18459

build/aclocal/ax_cxx_compile_stdcxx.m4

@@ -33,19 +33,19 @@
 #   Copyright (c) 2014, 2015 Google Inc.; contributed by Alexey Sokolov <sokolov@google.com>
 #   Copyright (c) 2015 Paul Norman <penorman@mac.com>
 #   Copyright (c) 2015 Moritz Klammler <moritz@klammler.eu>
-#   Copyright (c) 2016 Krzesimir Nowak <qdlacz@gmail.com>
+#   Copyright (c) 2016, 2018 Krzesimir Nowak <qdlacz@gmail.com>
+#   Copyright (c) 2019 Enji Cooper <yaneurabeya@gmail.com>
 #
 #   Copying and distribution of this file, with or without modification, are
 #   permitted in any medium without royalty provided the copyright notice
 #   and this notice are preserved.  This file is offered as-is, without any
 #   warranty.
 
-#serial 7
+#serial 11
 
 dnl  This macro is based on the code from the AX_CXX_COMPILE_STDCXX_11 macro
 dnl  (serial version number 13).
 
-AX_REQUIRE_DEFINED([AC_MSG_WARN])
 AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl
   m4_if([$1], [11], [ax_cxx_compile_alternatives="11 0x"],
         [$1], [14], [ax_cxx_compile_alternatives="14 1y"],
@@ -61,14 +61,6 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl
         [m4_fatal([invalid third argument `$3' to AX_CXX_COMPILE_STDCXX])])
   AC_LANG_PUSH([C++])dnl
   ac_success=no
-  AC_CACHE_CHECK(whether $CXX supports C++$1 features by default,
-  ax_cv_cxx_compile_cxx$1,
-  [AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])],
-    [ax_cv_cxx_compile_cxx$1=yes],
-    [ax_cv_cxx_compile_cxx$1=no])])
-  if test x$ax_cv_cxx_compile_cxx$1 = xyes; then
-    ac_success=yes
-  fi
 
   m4_if([$2], [noext], [], [dnl
   if test x$ac_success = xno; then
@@ -139,7 +131,6 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl
               [define if the compiler supports basic C++$1 syntax])
   fi
   AC_SUBST(HAVE_CXX$1)
-  m4_if([$1], [17], [AC_MSG_WARN([C++17 is not yet standardized, so the checks may change in incompatible ways anytime])])
 ])
 
 
@@ -199,11 +190,13 @@ namespace cxx11
 
     struct Base
     {
+      virtual ~Base() {}
       virtual void f() {}
     };
 
     struct Derived : public Base
     {
+      virtual ~Derived() override {}
       virtual void f() override {}
     };
 
@@ -587,20 +580,12 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_17], [[
 
 #error "This is not a C++ compiler"
 
-#elif __cplusplus <= 201402L
+#elif __cplusplus < 201703L
 
 #error "This is not a C++17 compiler"
 
 #else
 
-#if defined(__clang__)
-  #define REALLY_CLANG
-#else
-  #if defined(__GNUC__)
-    #define REALLY_GCC
-  #endif
-#endif
-
 #include <initializer_list>
 #include <utility>
 #include <type_traits>
@@ -608,16 +593,12 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_17], [[
 namespace cxx17
 {
 
-#if !defined(REALLY_CLANG)
   namespace test_constexpr_lambdas
   {
 
-    // TODO: test it with clang++ from git
-
     constexpr int foo = [](){return 42;}();
 
   }
-#endif // !defined(REALLY_CLANG)
 
   namespace test::nested_namespace::definitions
   {
@@ -852,12 +833,9 @@ namespace cxx17
 
   }
 
-#if !defined(REALLY_CLANG)
   namespace test_template_argument_deduction_for_class_templates
   {
 
-    // TODO: test it with clang++ from git
-
     template <typename T1, typename T2>
     struct pair
     {
@@ -876,7 +854,6 @@ namespace cxx17
     }
 
   }
-#endif // !defined(REALLY_CLANG)
 
   namespace test_non_type_auto_template_parameters
   {
@@ -890,12 +867,9 @@ namespace cxx17
 
   }
 
-#if !defined(REALLY_CLANG)
   namespace test_structured_bindings
   {
 
-    // TODO: test it with clang++ from git
-
     int arr[2] = { 1, 2 };
     std::pair<int, int> pr = { 1, 2 };
 
@@ -927,14 +901,10 @@ namespace cxx17
     const auto [ x3, y3 ] = f3();
 
   }
-#endif // !defined(REALLY_CLANG)
 
-#if !defined(REALLY_CLANG)
   namespace test_exception_spec_type_system
   {
 
-    // TODO: test it with clang++ from git
-
     struct Good {};
     struct Bad {};
 
@@ -952,7 +922,6 @@ namespace cxx17
     static_assert (std::is_same_v<Good, decltype(f(g1, g2))>);
 
   }
-#endif // !defined(REALLY_CLANG)
 
   namespace test_inline_variables
   {
@@ -977,6 +946,6 @@ namespace cxx17
 
 }  // namespace cxx17
 
-#endif  // __cplusplus <= 201402L
+#endif  // __cplusplus < 201703L
 
 ]])

build/aclocal/ax_func_which_gethostbyname_r.m4

@@ -1,35 +1,74 @@
-dnl @synopsis AX_FUNC_WHICH_GETHOSTBYNAME_R
-dnl
-dnl Determines which historical variant of the gethostbyname_r() call
-dnl (taking three, five, or six arguments) is available on the system
-dnl and defines one of the following macros accordingly:
-dnl
-dnl   HAVE_FUNC_GETHOSTBYNAME_R_6
-dnl   HAVE_FUNC_GETHOSTBYNAME_R_5
-dnl   HAVE_FUNC_GETHOSTBYNAME_R_3
-dnl
-dnl If used in conjunction with gethostname.c, the API demonstrated in
-dnl test.c can be used regardless of which gethostbyname_r() is
-dnl available. These example files can be found at
-dnl http://www.csn.ul.ie/~caolan/publink/gethostbyname_r
-dnl
-dnl based on David Arnold's autoconf suggestion in the threads faq
-dnl
-dnl Originally named "AC_caolan_FUNC_WHICH_GETHOSTBYNAME_R". Rewritten
-dnl for Autoconf 2.5x by Daniel Richard G.
-dnl
-dnl @category InstalledPackages
-dnl @author Caolan McNamara <caolan@skynet.ie>
-dnl @author Daniel Richard G. <skunk@iskunk.org>
-dnl @version 2005-01-21
-dnl @license GPLWithACException
+# ==================================================================================
+#  https://www.gnu.org/software/autoconf-archive/ax_func_which_gethostbyname_r.html
+# ==================================================================================
+#
+# SYNOPSIS
+#
+#   AX_FUNC_WHICH_GETHOSTBYNAME_R
+#
+# DESCRIPTION
+#
+#   Determines which historical variant of the gethostbyname_r() call
+#   (taking three, five, or six arguments) is available on the system and
+#   defines one of the following macros accordingly:
+#
+#     HAVE_FUNC_GETHOSTBYNAME_R_6
+#     HAVE_FUNC_GETHOSTBYNAME_R_5
+#     HAVE_FUNC_GETHOSTBYNAME_R_3
+#
+#   as well as
+#
+#     HAVE_GETHOSTBYNAME_R
+#
+#   If used in conjunction with gethostname.c, the API demonstrated in
+#   test.c can be used regardless of which gethostbyname_r() is available.
+#   These example files can be found at
+#   http://www.csn.ul.ie/~caolan/publink/gethostbyname_r
+#
+#   based on David Arnold's autoconf suggestion in the threads faq
+#
+#   Originally named "AC_caolan_FUNC_WHICH_GETHOSTBYNAME_R". Rewritten for
+#   Autoconf 2.5x, and updated for 2.68 by Daniel Richard G.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Caolan McNamara <caolan@skynet.ie>
+#   Copyright (c) 2008 Daniel Richard G. <skunk@iskunk.org>
+#
+#   This program is free software; you can redistribute it and/or modify it
+#   under the terms of the GNU General Public License as published by the
+#   Free Software Foundation; either version 2 of the License, or (at your
+#   option) any later version.
+#
+#   This program 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 General
+#   Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License along
+#   with this program. If not, see <https://www.gnu.org/licenses/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 8
 
 AC_DEFUN([AX_FUNC_WHICH_GETHOSTBYNAME_R], [
 
-    AC_LANG_PUSH(C)
+    AC_LANG_PUSH([C])
     AC_MSG_CHECKING([how many arguments gethostbyname_r() takes])
 
-    AC_CACHE_VAL(ac_cv_func_which_gethostbyname_r, [
+    AC_CACHE_VAL([ac_cv_func_which_gethostbyname_r], [
 
 ################################################################
 
@@ -44,16 +83,12 @@ ac_cv_func_which_gethostbyname_r=unknown
 # netdb.h is not declaring the function, and the compiler is thereby
 # assuming an implicit prototype. In which case, we're out of luck.
 #
-AC_COMPILE_IFELSE(
-    [AC_LANG_PROGRAM(
-        [[#include <netdb.h>]],
-        [[
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <netdb.h>],
+        [
             char *name = "www.gnu.org";
             (void)gethostbyname_r(name) /* ; */
-        ]]
-    )],
-    ac_cv_func_which_gethostbyname_r=no
-    )
+        ])],
+    [ac_cv_func_which_gethostbyname_r=no])
 
 #
 # SIX ARGUMENTS
@@ -62,20 +97,16 @@ AC_COMPILE_IFELSE(
 
 if test "$ac_cv_func_which_gethostbyname_r" = "unknown"; then
 
-AC_COMPILE_IFELSE(
-    [AC_LANG_PROGRAM(
-        [[#include <netdb.h>]],
-        [[
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <netdb.h>],
+        [
             char *name = "www.gnu.org";
             struct hostent ret, *retp;
             char buf@<:@1024@:>@;
             int buflen = 1024;
             int my_h_errno;
             (void)gethostbyname_r(name, &ret, buf, buflen, &retp, &my_h_errno) /* ; */
-        ]]
-    )],
-    ac_cv_func_which_gethostbyname_r=six
-    )
+        ])],
+    [ac_cv_func_which_gethostbyname_r=six])
 
 fi
 
@@ -86,20 +117,16 @@ fi
 
 if test "$ac_cv_func_which_gethostbyname_r" = "unknown"; then
 
-AC_COMPILE_IFELSE(
-    [AC_LANG_PROGRAM(
-	[[#include <netdb.h>]],
-        [[
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <netdb.h>],
+        [
             char *name = "www.gnu.org";
             struct hostent ret;
             char buf@<:@1024@:>@;
             int buflen = 1024;
             int my_h_errno;
             (void)gethostbyname_r(name, &ret, buf, buflen, &my_h_errno) /* ; */
-        ]]
-    )],
-    ac_cv_func_which_gethostbyname_r=five
-    )
+        ])],
+    [ac_cv_func_which_gethostbyname_r=five])
 
 fi
 
@@ -110,18 +137,14 @@ fi
 
 if test "$ac_cv_func_which_gethostbyname_r" = "unknown"; then
 
-AC_COMPILE_IFELSE(
-    [AC_LANG_PROGRAM(
-        [[#include <netdb.h>]],
-        [[
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <netdb.h>],
+        [
             char *name = "www.gnu.org";
             struct hostent ret;
             struct hostent_data data;
             (void)gethostbyname_r(name, &ret, &data) /* ; */
-        ]]
-    )],
-    ac_cv_func_which_gethostbyname_r=three
-    )
+        ])],
+    [ac_cv_func_which_gethostbyname_r=three])
 
 fi
 
@@ -129,20 +152,30 @@ fi
 
 ]) dnl end AC_CACHE_VAL
 
+case "$ac_cv_func_which_gethostbyname_r" in
+    three|five|six)
+    AC_DEFINE([HAVE_GETHOSTBYNAME_R], [1],
+              [Define to 1 if you have some form of gethostbyname_r().])
+    ;;
+esac
+
 case "$ac_cv_func_which_gethostbyname_r" in
     three)
     AC_MSG_RESULT([three])
-    AC_DEFINE(HAVE_FUNC_GETHOSTBYNAME_R_3)
+    AC_DEFINE([HAVE_FUNC_GETHOSTBYNAME_R_3], [1],
+              [Define to 1 if you have the three-argument form of gethostbyname_r().])
     ;;
 
     five)
     AC_MSG_RESULT([five])
-    AC_DEFINE(HAVE_FUNC_GETHOSTBYNAME_R_5)
+    AC_DEFINE([HAVE_FUNC_GETHOSTBYNAME_R_5], [1],
+              [Define to 1 if you have the five-argument form of gethostbyname_r().])
     ;;
 
     six)
     AC_MSG_RESULT([six])
-    AC_DEFINE(HAVE_FUNC_GETHOSTBYNAME_R_6)
+    AC_DEFINE([HAVE_FUNC_GETHOSTBYNAME_R_6], [1],
+              [Define to 1 if you have the six-argument form of gethostbyname_r().])
     ;;
 
     no)
@@ -158,6 +191,6 @@ case "$ac_cv_func_which_gethostbyname_r" in
     ;;
 esac
 
-AC_LANG_POP(C)
+AC_LANG_POP
 
 ]) dnl end AC_DEFUN