As discussed at the thread at
http://gcc.gnu.org/ml/gcc-patches/2013-11/msg00505.html , the new
-fisolate-erroneous-paths option does not work for Go. The option
can change nil pointer deferences into a trap, but for Go we want those
to consistently be a panic. This patch disables the option for Go.
If the option changes in a way that lets Go work, such as by disabling
the option when using -fnon-call-exceptions, then this patch can be
reverted.
Bootstrapped and ran Go testsuite on x86_64-unknown-linux-gnu.
Committed to mainline.
Ian
2013-11-06 Ian Lance Taylor <[email protected]>
* go-lang.c (go_langhook_post_options): If
-fisolate-erroneous-paths was turned on by an optimization option,
turn it off.
Index: go-lang.c
===================================================================
--- go-lang.c (revision 204430)
+++ go-lang.c (working copy)
@@ -268,6 +268,12 @@ go_langhook_post_options (const char **p
if (flag_excess_precision_cmdline == EXCESS_PRECISION_DEFAULT)
flag_excess_precision_cmdline = EXCESS_PRECISION_STANDARD;
+ /* The isolate_erroneous_paths optimization can change a nil
+ dereference from a panic to a trap, so we have to disable it for
+ Go, even though it is normally enabled by -O2. */
+ if (!global_options_set.x_flag_isolate_erroneous_paths)
+ global_options.x_flag_isolate_erroneous_paths = 0;
+
/* Returning false means that the backend should be used. */
return false;
}
