build-sys: use AC_LANG_SOURCE to suppress warnings

Messages bellow be supressed by using AC_LANG_SOURCE macro around
code test blocks.

m4/tls.m4:13: AX_CHECK_TLS is expanded from...
configure.ac:335: the top level
configure.ac:335: warning: AC_LANG_CONFTEST: no AC_LANG_SOURCE call detected in body
../../lib/autoconf/lang.m4:193: AC_LANG_CONFTEST is expanded from...
../../lib/autoconf/general.m4:2660: _AC_LINK_IFELSE is expanded from...
../../lib/autoconf/general.m4:2677: AC_LINK_IFELSE is expanded from...
../../lib/m4sugar/m4sh.m4:605: AS_IF is expanded from...
../../lib/autoconf/general.m4:2728: _AC_RUN_IFELSE is expanded from...
../../lib/m4sugar/m4sh.m4:605: AS_IF is expanded from...
../../lib/autoconf/general.m4:2747: AC_RUN_IFELSE is expanded from...
../../lib/m4sugar/m4sh.m4:605: AS_IF is expanded from...
../../lib/autoconf/general.m4:2030: AC_CACHE_VAL is expanded from...
../../lib/autoconf/general.m4:2051: AC_CACHE_CHECK is expanded from...
m4/tls.m4:13: AX_CHECK_TLS is expanded from...
configure.ac:335: the top level

Reference to documentation;
http://www.flameeyes.eu/autotools-mythbuster/forwardporting/autoconf.html#id1168723648533

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/m4/tls.m4 b/m4/tls.m4
index 7adb09acda668bc79c8a2bba95de3ffa921efbe2..d2243aac28752f12a7655ae04a549e495fb6fb90 100644 (file)
--- a/m4/tls.m4
+++ b/m4/tls.m4
@@ -20,14 +20,14 @@ AC_DEFUN([AX_CHECK_TLS], [
 
   AC_CACHE_CHECK([whether the target supports thread-local storage],
                 ax_cv_have_tls, [
-    AC_RUN_IFELSE([__thread int a; int b; int main() { return a = b; }],
+    AC_RUN_IFELSE([AC_LANG_SOURCE([__thread int a; int b; int main() { return a = b; }])],
       [dnl If the test case passed with dynamic linking, try again with
        dnl static linking, but only if static linking is supported (not
        dnl on Solaris 10).  This fails with some older Red Hat releases.
       chktls_save_LDFLAGS="$LDFLAGS"
       LDFLAGS="-static $LDFLAGS"
-      AC_LINK_IFELSE([int main() { return 0; }],
-       AC_RUN_IFELSE([__thread int a; int b; int main() { return a = b; }],
+      AC_LINK_IFELSE([AC_LANG_SOURCE([int main() { return 0; }])],
+       AC_RUN_IFELSE([AC_LANG_SOURCE([__thread int a; int b; int main() { return a = b; }])],
                      [ax_cv_have_tls=yes], [ax_cv_have_tls=no],[]),
        [ax_cv_have_tls=yes])
       LDFLAGS="$chktls_save_LDFLAGS"
@@ -82,7 +82,7 @@ AC_DEFUN([AX_CHECK_TLS], [
       [ax_cv_have_tls=no],
       [dnl This is the cross-compiling case. Assume libc supports TLS if the
        dnl binutils and the compiler do.
-       AC_LINK_IFELSE([__thread int a; int b; int main() { return a = b; }],
+       AC_LINK_IFELSE([AC_LANG_SOURCE([__thread int a; int b; int main() { return a = b; }])],
         [chktls_save_LDFLAGS="$LDFLAGS"
          dnl Shared library options may depend on the host; this check
          dnl is only known to be needed for GNU/Linux.
@@ -94,8 +94,8 @@ AC_DEFUN([AX_CHECK_TLS], [
          chktls_save_CFLAGS="$CFLAGS"
          CFLAGS="-fPIC $CFLAGS"
          dnl If -shared works, test if TLS works in a shared library.
-         AC_LINK_IFELSE([int f() { return 0; }],
-           [AC_LINK_IFELSE([__thread int a; int b; int f() { return a = b; }],
+         AC_LINK_IFELSE([AC_LANG_SOURCE([int f() { return 0; }])],
+           [AC_LINK_IFELSE([AC_LANG_SOURCE([__thread int a; int b; int f() { return a = b; }])],
              [ax_cv_have_tls=yes],
              [ax_cv_have_tls=no])],
            [ax_cv_have_tls=yes])