Replace AC_TRY_LINK and AC_LANG_

Autoconf 2.50 in 2001 made several macros obsolete. These include macros
for temporary changing the language - AC_LANG_SAVE, AC_LANG_CPLUSPLUS,
and AC_LANG_RESTORE. Instead of these the AC_LANG_PUSH and
AC_LANG_POP macros should be used with later Autoconf versions.

AC_TRY_LINK macros should be replaced with AC_LINK_IFELSE and
AC_LANG_PROGRAM.

Refs:
- http://git.savannah.gnu.org/cgit/autoconf.git/tree/NEWS
- https://www.gnu.org/software/autoconf/manual/autoconf-2.69/html_node/Language-Choice.html
- https://www.gnu.org/software/autoconf/manual/autoconf-2.69/html_node/Obsolete-Macros.html

1 files changed, 7 insertions, 8 deletions

diff --git a/m4/ax_cxx_have_system_v_math.m4 b/m4/ax_cxx_have_system_v_math.m4
index 56b3dc0..fd10860 100644
--- a/m4/ax_cxx_have_system_v_math.m4
+++ b/m4/ax_cxx_have_system_v_math.m4
@@ -22,17 +22,16 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 7
+#serial 8
 
 AU_ALIAS([AC_CXX_HAVE_SYSTEM_V_MATH], [AX_CXX_HAVE_SYSTEM_V_MATH])
 AC_DEFUN([AX_CXX_HAVE_SYSTEM_V_MATH],
 [AC_CACHE_CHECK(whether the compiler supports System V math library,
 ax_cv_cxx_have_system_v_math,
-[AC_LANG_SAVE
- AC_LANG_CPLUSPLUS
+[AC_LANG_PUSH([C++])
  ac_save_LIBS="$LIBS"
  LIBS="$LIBS -lm"
- AC_TRY_LINK([
+ AC_LINK_IFELSE([AC_LANG_PROGRAM([[
 #ifndef _ALL_SOURCE
  #define _ALL_SOURCE
 #endif
@@ -42,13 +41,13 @@ ax_cv_cxx_have_system_v_math,
 #ifndef _XOPEN_SOURCE_EXTENDED
  #define _XOPEN_SOURCE_EXTENDED 1
 #endif
-#include <math.h>],[double x = 1.0; double y = 1.0;
+#include <math.h>]], [[double x = 1.0; double y = 1.0;
 _class(x); trunc(x); finite(x); itrunc(x); nearest(x); rsqrt(x); uitrunc(x);
 copysign(x,y); drem(x,y); unordered(x,y);
-return 0;],
- ax_cv_cxx_have_system_v_math=yes, ax_cv_cxx_have_system_v_math=no)
+return 0;]])],
+ [ax_cv_cxx_have_system_v_math=yes], [ax_cv_cxx_have_system_v_math=no])
  LIBS="$ac_save_LIBS"
- AC_LANG_RESTORE
+ AC_LANG_POP([C++])
 ])
 if test "$ax_cv_cxx_have_system_v_math" = yes; then
   AC_DEFINE(HAVE_SYSTEM_V_MATH,,[define if the compiler supports System V math library])