On Mon, 19 Jun 2017, Jakub Jelinek wrote:
> Hi!
>
> Martin's recent patch that introduced sanitize_flags_p causes us to
> instrument operations even when current_function_decl is NULL. If it
> is valid constant expression it will be folded away soon, otherwise
> usually we emit a runtime initializer in the static ctors function for
> it. In any case, neither gimple_add_tmp_var that create_tmp_var calls
> normark_addressable actually work in that case, fixed thusly,
> bootstrapped/regtested on x86_64-linux and i686-linux plus
> bootstrapped/regtested with bootstrap-ubsan, ok for trunk?
Ok.
Richard.
> 2017-06-19 Jakub Jelinek <ja...@redhat.com>
>
> PR sanitizer/81111
> * ubsan.c (ubsan_encode_value): If current_function_decl is NULL,
> use create_tmp_var_raw instead of create_tmp_var, mark it addressable
> just by setting TREE_ADDRESSABLE on the result and use a TARGET_EXPR.
>
> * g++.dg/ubsan/pr81111.C: New test.
>
> --- gcc/ubsan.c.jj 2017-06-16 13:27:48.000000000 +0200
> +++ gcc/ubsan.c 2017-06-16 16:28:29.099155949 +0200
> @@ -145,9 +145,17 @@ ubsan_encode_value (tree t, bool in_expa
> {
> /* The reason for this is that we don't want to pessimize
> code by making vars unnecessarily addressable. */
> - tree var = create_tmp_var (type);
> - tree tem = build2 (MODIFY_EXPR, void_type_node, var, t);
> - mark_addressable (var);
> + tree var;
> + if (current_function_decl)
> + {
> + var = create_tmp_var (type);
> + mark_addressable (var);
> + }
> + else
> + {
> + var = create_tmp_var_raw (type);
> + TREE_ADDRESSABLE (var) = 1;
> + }
> if (in_expand_p)
> {
> rtx mem
> @@ -158,8 +166,17 @@ ubsan_encode_value (tree t, bool in_expa
> expand_assignment (var, t, false);
> return build_fold_addr_expr (var);
> }
> - t = build_fold_addr_expr (var);
> - return build2 (COMPOUND_EXPR, TREE_TYPE (t), tem, t);
> + if (current_function_decl)
> + {
> + tree tem = build2 (MODIFY_EXPR, void_type_node, var, t);
> + t = build_fold_addr_expr (var);
> + return build2 (COMPOUND_EXPR, TREE_TYPE (t), tem, t);
> + }
> + else
> + {
> + var = build4 (TARGET_EXPR, type, var, t, NULL_TREE, NULL_TREE);
> + return build_fold_addr_expr (var);
> + }
> }
> else
> return build_fold_addr_expr (t);
> --- gcc/testsuite/g++.dg/ubsan/pr81111.C.jj 2017-06-16 15:39:57.752886010
> +0200
> +++ gcc/testsuite/g++.dg/ubsan/pr81111.C 2017-06-16 15:39:37.000000000
> +0200
> @@ -0,0 +1,45 @@
> +// PR sanitizer/81111
> +// { dg-do compile }
> +// { dg-options "-fsanitize=shift" }
> +
> +template <typename V>
> +struct N
> +{
> + static const V m = (((V)(-1) < 0)
> + ? (V)1 << (sizeof(V) * __CHAR_BIT__ - ((V)(-1) < 0))
> + : (V) 0);
> +};
> +
> +template<typename V>
> +const V N<V>::m;
> +
> +template <typename V>
> +struct O
> +{
> + static const V m = (V)1 << sizeof(V) * __CHAR_BIT__;
> +};
> +
> +template<typename V>
> +const V O<V>::m;
> +
> +void
> +foo ()
> +{
> + N<long long>::m;
> + N<unsigned long long>::m;
> +#ifdef __SIZEOF_INT128__
> + N<__int128>::m;
> + N<unsigned __int128>::m;
> +#endif
> +}
> +
> +void
> +bar ()
> +{
> + O<long long>::m;
> + O<unsigned long long>::m;
> +#ifdef __SIZEOF_INT128__
> + O<__int128>::m;
> + O<unsigned __int128>::m;
> +#endif
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
