Disallow -fvtable-verify and -flto to be used together.

Vtable verification currently does not work properly with
link time optimization.  Until this can be fixed users should
not be allowed to specify both options together.

2019-09-04  Caroline Tice  <cmtice@google.com>
 
        *  opts.c (finish_options):  Disallow -fvtable-verify and -flto to be
           specified together.

From-SVN: r275388

gcc/ChangeLog

+2019-09-04  Caroline Tice  <cmtice@google.com>
+
+	* opts.c (finish_options): Disallow -fvtable-verify and -flto to be
+	specified together.
+
 2019-09-04  Marek Polacek  <polacek@redhat.com>
 
 	* doc/invoke.texi: Remove -fdeduce-init-list documentation.

gcc/opts.c

@@ -1226,6 +1226,10 @@ finish_options (struct gcc_options *opts, struct gcc_options *opts_set,
   if (opts->x_flag_live_patching && opts->x_flag_lto)
     sorry ("live patching is not supported with LTO");
 
+  /* Currently vtable verification is not supported for LTO */
+  if (opts->x_flag_vtable_verify && opts->x_flag_lto)
+    sorry ("vtable verification is not supported with LTO");
+
   /* Control IPA optimizations based on different -flive-patching level.  */
   if (opts->x_flag_live_patching)
     {