Move the check for -static-libgcc until after AC_LANG_WERROR

has been called and use AX_CHECK_COMPILE_FLAG().

configure

@@ -14628,43 +14628,6 @@ else
   as_fn_error $? "Your C compiler doesn't support variadic macros, try building with gcc instead" "$LINENO" 5
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-if test X"$with_gnu_ld" != "yes" -a -n "$GCC"; then
-    _CFLAGS="$CFLAGS"
-    CFLAGS="$CFLAGS -static-libgcc"
-    { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CC understands -static-libgcc" >&5
-$as_echo_n "checking whether $CC understands -static-libgcc... " >&6; }
-if ${sudo_cv_var_gcc_static_libgcc+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  sudo_cv_var_gcc_static_libgcc=yes
-else
-  sudo_cv_var_gcc_static_libgcc=no
-
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-
-
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $sudo_cv_var_gcc_static_libgcc" >&5
-$as_echo "$sudo_cv_var_gcc_static_libgcc" >&6; }
-    CFLAGS="$_CFLAGS"
-    if test "$sudo_cv_var_gcc_static_libgcc" = "yes"; then
-	LT_LDFLAGS="$LT_LDFLAGS -Wc,-static-libgcc"
-    fi
-fi
 
 for ac_prog in 'bison -y' byacc
 do
@@ -20080,6 +20043,45 @@ $as_echo "$iolog_dir" >&6; }
 
 
 ac_c_werror_flag=yes
+
+if test -n "$GCC" -a "$lt_cv_prog_gnu_ld" != "yes" -a -n "$GCC"; then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether C compiler accepts -static-libgcc" >&5
+$as_echo_n "checking whether C compiler accepts -static-libgcc... " >&6; }
+if ${ax_cv_check_cflags___static_libgcc+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+  ax_check_save_flags=$CFLAGS
+  CFLAGS="$CFLAGS  -static-libgcc"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ax_cv_check_cflags___static_libgcc=yes
+else
+  ax_cv_check_cflags___static_libgcc=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  CFLAGS=$ax_check_save_flags
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ax_cv_check_cflags___static_libgcc" >&5
+$as_echo "$ax_cv_check_cflags___static_libgcc" >&6; }
+if test x"$ax_cv_check_cflags___static_libgcc" = xyes; then :
+  LT_LDFLAGS="$LT_LDFLAGS -Wc,-static-libgcc"
+else
+  :
+fi
+
+fi
+
 as_CACHEVAR=`$as_echo "ax_cv_check_cflags__-fvisibility=hidden" | $as_tr_sh`
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether C compiler accepts -fvisibility=hidden" >&5
 $as_echo_n "checking whether C compiler accepts -fvisibility=hidden... " >&6; }

configure.in

@@ -1975,23 +1975,6 @@ AC_INCLUDES_DEFAULT
 # define sudo_fprintf(fp, ...) fprintf((fp), __VA_ARGS__)
 #endif
 ], [sudo_fprintf(stderr, "a %s", "test");])], [], [AC_MSG_ERROR([Your C compiler doesn't support variadic macros, try building with gcc instead])])
-if test X"$with_gnu_ld" != "yes" -a -n "$GCC"; then
-    _CFLAGS="$CFLAGS"
-    CFLAGS="$CFLAGS -static-libgcc"
-    AC_CACHE_CHECK([whether $CC understands -static-libgcc],
-	[sudo_cv_var_gcc_static_libgcc],
-	[AC_LINK_IFELSE(
-	    [AC_LANG_PROGRAM([[]], [[]])],
-		[sudo_cv_var_gcc_static_libgcc=yes],
-		[sudo_cv_var_gcc_static_libgcc=no]
-	    )
-	]
-    )
-    CFLAGS="$_CFLAGS"
-    if test "$sudo_cv_var_gcc_static_libgcc" = "yes"; then
-	LT_LDFLAGS="$LT_LDFLAGS -Wc,-static-libgcc"
-    fi
-fi
 
 dnl
 dnl Program checks
@@ -3169,11 +3152,25 @@ SUDO_TIMEDIR
 SUDO_IO_LOGDIR
 
 dnl
-dnl Check for gcc 4.0-style symbol visibility support.
+dnl Turn warnings into errors.
-dnl This must be towards the end as it turns warnings
+dnl All compiler/loader tests after this point will fail if 
-dnl into fatal errors (and there is no way to undo that)
+dnl a warning is displayed (nornally, warnings are not fata).
 dnl
 AC_LANG_WERROR
+
+dnl
+dnl If compiler supports the -static-libgcc flag use it unless we have
+dnl GNU ld (which can avoid linking in libgcc when it is not needed).
+dnl This test relies on AC_LANG_WERROR
+dnl
+if test -n "$GCC" -a "$lt_cv_prog_gnu_ld" != "yes" -a -n "$GCC"; then
+    AX_CHECK_COMPILE_FLAG([-static-libgcc], [LT_LDFLAGS="$LT_LDFLAGS -Wc,-static-libgcc"])
+fi
+
+dnl
+dnl Check for symbol visibility support.
+dnl This test relies on AC_LANG_WERROR
+dnl
 AX_CHECK_COMPILE_FLAG([-fvisibility=hidden], [
     AC_DEFINE(HAVE_DSO_VISIBILITY)
     CFLAGS="${CFLAGS} -fvisibility=hidden"
@@ -3202,6 +3199,7 @@ AX_CHECK_COMPILE_FLAG([-fvisibility=hidden], [
 dnl
 dnl If the compiler doesn't have symbol visibility support, it may
 dnl support version scripts (only GNU and Solaris ld).
+dnl This test relies on AC_LANG_WERROR
 dnl
 if test -n "$LT_LDEXPORTS"; then
     if test "$lt_cv_prog_gnu_ld" = "yes"; then
@@ -3241,8 +3239,7 @@ fi
 
 dnl
 dnl Check for -fstack-protector and -z relro support
-dnl This after the call to AC_LANG_WERROR so that warnings
+dnl This test relies on AC_LANG_WERROR
-dnl are treated as fatal errors.
 dnl
 if test "$enable_hardening" != "no"; then
     AX_CHECK_COMPILE_FLAG([-fstack-protector], [