Provide proper error message for -flto=abcd.

2019-08-09  Martin Liska  <mliska@suse.cz>

	* opts.c (common_handle_option): Error for an invalid argument
	to -flto=.
2019-08-09  Martin Liska  <mliska@suse.cz>

	* gcc.dg/spellcheck-options-21.c: New test.

From-SVN: r274231

gcc/ChangeLog

 2019-08-09  Martin Liska  <mliska@suse.cz>
 
+	* opts.c (common_handle_option): Error for an invalid argument
+	to -flto=.
+
+2019-08-09  Martin Liska  <mliska@suse.cz>
+
 	* ipa-icf.c (sem_function::merge): Define AUTO_DUMP_SCOPE and
 	use dump_printf to report optimization.
 	(sem_variable::merge): Likwise.

gcc/opts.c

@@ -2822,6 +2822,14 @@ common_handle_option (struct gcc_options *opts,
       opts->x_flag_lto = value ? "" : NULL;
       break;
 
+    case OPT_flto_:
+      if (strcmp (arg, "none") != 0
+	  && strcmp (arg, "jobserver") != 0
+	  && atoi (arg) == 0)
+	error_at (loc,
+		  "unrecognized argument to %<-flto=%> option: %qs", arg);
+      break;
+
     case OPT_w:
       dc->dc_inhibit_warnings = true;
       break;

gcc/testsuite/ChangeLog

 2019-08-09  Martin Liska  <mliska@suse.cz>
 
+	* gcc.dg/spellcheck-options-21.c: New test.
+
+2019-08-09  Martin Liska  <mliska@suse.cz>
+
 	* g++.dg/ipa/ipa-icf-2.C: Add -optimized to -fdump-ipa-icf.
 	* g++.dg/ipa/ipa-icf-3.C: Likewise.
 	* g++.dg/ipa/ipa-icf-4.C: Likewise.

gcc/testsuite/gcc.dg/spellcheck-options-21.c

+/* { dg-do compile } */
+/* { dg-options "-flto=sparta" } */
+/* { dg-error "unrecognized argument to '-flto=' option: 'sparta'" "" { target *-*-* } 0 } */