Hi!
GCC 4.2 (but I think not the latest tip of GCC 4.2 branch) has broken value
initialization, see PR33916. The following patch provides a workaround for
that. Tested with GCC 4.2 on a reduced testcase I've distilled from the
assign_param_data_one class which has been miscompiled the same,
and normally bootstrapped/regtested on x86_64-linux and i686-linux with
a recentish system GCC. Ok for trunk?
2020-04-16 Jakub Jelinek <ja...@redhat.com>
PR bootstrap/89494
* function.c (assign_parm_find_data_types): Add workaround for
BROKEN_VALUE_INITIALIZATION compilers.
--- gcc/function.c.jj 2020-01-12 11:54:36.606410497 +0100
+++ gcc/function.c 2020-04-15 14:15:29.269495427 +0200
@@ -2414,7 +2414,15 @@ assign_parm_find_data_types (struct assi
{
int unsignedp;
+#ifndef BROKEN_VALUE_INITIALIZATION
*data = assign_parm_data_one ();
+#else
+ /* Old versions of GCC used to miscompile the above by only initializing
+ the members with explicit constructors and copying garbage
+ to the other members. */
+ assign_parm_data_one zero_data = {};
+ *data = zero_data;
+#endif
/* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
if (!cfun->stdarg)
Jakub
