configure.ac: Add -Wc++-compat to ac_libibety_warn_cflags where supported.

        * configure.ac: Add -Wc++-compat to ac_libibety_warn_cflags
          where supported. 
        * configure: Regenerated.

From-SVN: r110375

libiberty/ChangeLog

+2006-01-29  Gabriel Dos Reis  <gdr@integrable-solutions.net>
+
+	* configure.ac: Add -Wc++-compat to ac_libibety_warn_cflags where
+	supported. 
+	* configure: Regenerated.
+
 2006-01-20  Carlos O'Donell  <carlos@codesourcery.com>
 
 	* testsuite/Makefile.in: Add test-expandargv test.

libiberty/configure.ac

@@ -113,9 +113,25 @@ GCC_NO_EXECUTABLES
 AC_PROG_CC
 AC_PROG_CPP_WERROR
 
+# Warn C++ incompatibilities if supported.
+AC_CACHE_CHECK(
+  [whether ${CC} accepts -Wc++-compat],
+  [ac_cv_prog_cc_w_cxx_compat],
+  [save_CFLAGS="$CFLAGS"
+  CFLAGS="-Wc++-compat"
+  AC_COMPILE_IFELSE([AC_LANG_SOURCE([[]])],
+                    [ac_cv_prog_cc_w_cxx_compat=yes],
+                    [ac_cv_prog_cc_w_cxx_compat=no])
+  CFLAGS="$save_CFLAGS"
+  ])
+
+
 if test x$GCC = xyes; then
   ac_libiberty_warn_cflags='-W -Wall -pedantic -Wwrite-strings -Wstrict-prototypes'
 fi
+if test $ac_cv_prog_cc_w_cxx_compat = yes ; then
+  ac_libiberty_warn_cflags="${ac_libiberty_warn_cflags} -Wc++-compat"
+fi
 AC_SUBST(ac_libiberty_warn_cflags)
 
 AC_PROG_CC_C_O