On Thu, 22 Mar 2018, Jakub Jelinek wrote:
> Hi!
>
> As the testcase shows, we can hit the assertion here (with code that is
> rejected only later on during expansion). Instead of the assertion, this
> patch just doesn't try to optimize those, maybe_optimize_ubsan_ptr_ifn
> is a pure optimization.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
Richard.
> 2018-03-22 Jakub Jelinek <ja...@redhat.com>
>
> PR sanitizer/85029
> * sanopt.c (maybe_optimize_ubsan_ptr_ifn): If DECL_REGISTER (base),
> just don't try to optimize it rather than assert it never happens.
>
> * g++.dg/ubsan/pr85029.C: New test.
>
> --- gcc/sanopt.c.jj 2018-03-14 09:49:45.462028237 +0100
> +++ gcc/sanopt.c 2018-03-22 08:20:30.639183003 +0100
> @@ -488,9 +488,9 @@ maybe_optimize_ubsan_ptr_ifn (sanopt_ctx
> &unsignedp, &reversep, &volatilep);
> if ((offset == NULL_TREE || TREE_CODE (offset) == INTEGER_CST)
> && DECL_P (base)
> + && !DECL_REGISTER (base)
> && pbitpos.is_constant (&bitpos))
> {
> - gcc_assert (!DECL_REGISTER (base));
> offset_int expr_offset;
> if (offset)
> expr_offset = wi::to_offset (offset) + bitpos / BITS_PER_UNIT;
> --- gcc/testsuite/g++.dg/ubsan/pr85029.C.jj 2018-03-22 08:22:34.952174863
> +0100
> +++ gcc/testsuite/g++.dg/ubsan/pr85029.C 2018-03-22 08:31:49.554138533
> +0100
> @@ -0,0 +1,15 @@
> +// PR sanitizer/85029
> +// { dg-do compile }
> +// { dg-skip-if "" { *-*-* } { "-flto -fno-fat-lto-objects" } }
> +// { dg-options "-fsanitize=undefined" }
> +
> +struct B {
> + virtual B bar ();
> + int e;
> +} register a; // { dg-error "register name not specified for 'a'" }
> +
> +int
> +foo (...)
> +{
> + return foo (a);
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
