AC_PROG_CC: don't check whether $CC supports "-c -o" together

This reverts commit ce48964f.  The extra code added by that commit was
planned to be used by future version of Automake, but the implementation
and future directions there have in the meantime be changed in a way
that makes the extra code in Autoconf superfluous.  Just get rid of it.

* lib/autoconf/c.m4 (AC_PROG_CC): Adjust.

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>

diff --git a/lib/autoconf/c.m4 b/lib/autoconf/c.m4
index a810a096bf5af7587186eda9aefe4eede84252fe..53fec833fab992bae6a1a4576148ac5bee7c04d5 100644 (file)
--- a/lib/autoconf/c.m4
+++ b/lib/autoconf/c.m4
@@ -490,31 +490,7 @@ _AC_PROG_CC_C11([ac_prog_cc_stdc=c11
                       ac_cv_prog_cc_stdc=$ac_cv_prog_cc_c89],
                      [ac_prog_cc_stdc=no
                       ac_cv_prog_cc_stdc=no])])])
-dnl This is a hook for Automake and its 'subdir-objects' mode, which
-dnl needs to know whether $CC supports "-c -o" together or not.  See
-dnl automake bug#13378, in particular <http://debbugs.gnu.org/13378#73>.
-dnl FIXME: there is some code duplication with AC_PROG_CC_C_O here.
-m4_ifdef([_AM_PROG_CC_C_O_HELPME],
-[set dummy $CC; ac_cc=`AS_ECHO(["$[2]"]) | \
-                       sed 's/[[^a-zA-Z0-9_]]/_/g;s/^[[0-9]]/_/'`
-AC_MSG_CHECKING([whether $CC understands -c and -o together])
-AC_CACHE_VAL([ac_cv_prog_cc_${ac_cc}_c_o],
-[AC_LANG_CONFTEST([AC_LANG_PROGRAM([])])
-# Make sure it works both with $CC and with simple cc.
-# We do the test twice because some compilers refuse to overwrite an
-# existing .o file with -o, though they will create one.
-ac_try='$CC -c conftest.$ac_ext -o conftest2.$ac_objext >&AS_MESSAGE_LOG_FD'
-rm -f conftest2.*
-if _AC_DO_VAR(ac_try) && test -f conftest2.$ac_objext
-then
-  AC_MSG_RESULT([yes])
-  eval ac_cv_prog_cc_${ac_cc}_c_o=yes
-else
-  AC_MSG_RESULT([no])
-  eval ac_cv_prog_cc_${ac_cc}_c_o=no
-fi
-rm -rf core conftest*
-])])dnl
+dnl
 AC_LANG_POP(C)dnl
 ])# AC_PROG_CC