On Wed, Apr 27, 2016 at 07:03:25PM +0200, Marek Polacek wrote:
> This test took forever to compile with -fsanitize=null, because the
> instrumentation was creating incredible amount of duplicated expressions, in a
> quadratic fashion. I think the problem is that we instrument &TARGET_EXPR <>
> expressions, which doesn't seem to be needed -- we only need to instrument the
> initializers in TARGET_EXPRs. With this patch, we avoid creating tons of
> useless
> expressions and the compile time is reduced from ~ infinity to <1s.
>
> Jakub, do you see any problem with this?
>
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
>
> 2016-04-27 Marek Polacek <pola...@redhat.com>
>
> PR sanitizer/70342
> * c-ubsan.c (ubsan_maybe_instrument_reference_or_call): Don't
> null-instrument &TARGET_EXPR <...>.
>
> * g++.dg/ubsan/null-7.C: New test.
I wonder if this wouldn't be better handled in tree_single_nonzero_warnv_p,
perhaps like:
case ADDR_EXPR:
{
tree base = TREE_OPERAND (t, 0);
if (!DECL_P (base))
base = get_base_address (base);
+
+ if (base && TREE_CODE (base) == TARGET_EXPR)
+ base = TARGET_EXPR_SLOT (base);
if (!base)
return false;
(untested)?
Jakub
