optc-gen.awk: Emit #error for -W*/-f*/-m* Enum without RejectNegative.

	* optc-gen.awk: Emit #error for -W*/-f*/-m* Enum without
	RejectNegative.

From-SVN: r244073

gcc/ChangeLog

 2017-01-04  Jakub Jelinek  <jakub@redhat.com>
 
+	* optc-gen.awk: Emit #error for -W*/-f*/-m* Enum without
+	RejectNegative.
+
 	* dwarf2out.c (output_loc_list): Don't throw away 64K+ location
 	descriptions for -gdwarf-5 and emit them as uleb128 instead of
 	2-byte data.

gcc/optc-gen.awk

@@ -326,6 +326,11 @@ for (i = 0; i < n_opts; i++) {
 			alias_data = "NULL, NULL, OPT_SPECIAL_ignore"
 		else
 			alias_data = "NULL, NULL, N_OPTS"
+		if (flag_set_p("Enum.*", flags[i])) {
+			if (!flag_set_p("RejectNegative", flags[i]) \
+			    && opts[i] ~ "^[Wfm]")
+				print "#error Enum allowing negative form"
+		}
 	} else {
 		alias_opt = nth_arg(0, alias_arg)
 		alias_posarg = nth_arg(1, alias_arg)