https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63956
--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Marek Polacek from comment #6)
> Earlier today I tried the following and it seemed to work, but I don't know
> constexpr.c, so it may be totally bogus.
>
> --- gcc/cp/constexpr.c
> +++ gcc/cp/constexpr.c
> @@ -1149,6 +1149,10 @@ cxx_eval_call_expression (const constexpr_ctx *ctx,
> tree t,
> constexpr_call *entry;
> bool depth_ok;
>
> + if (fun == NULL_TREE
> + && CALL_EXPR_IFN (t) == IFN_UBSAN_NULL)
> + return t;
> +
> if (TREE_CODE (fun) != FUNCTION_DECL)
> {
> /* Might be a constexpr function pointer. */
The -fsanitize=vptr patch has:
if (is_builtin_fn (fun))
- return cxx_eval_builtin_function_call (old_call, t, allow_non_constant,
- addr, non_constant_p, overflow_p);
+ {
+ /* Ignore -fsanitize=vptr instrumentation. */
+ if ((flag_sanitize & SANITIZE_VPTR)
+ && DECL_BUILT_IN_CLASS (fun) == BUILT_IN_NORMAL
+ && (DECL_FUNCTION_CODE (fun)
+ == ((flag_sanitize_recover & SANITIZE_VPTR)
+ ? BUILT_IN_UBSAN_HANDLE_DYNAMIC_TYPE_CACHE_MISS
+ : BUILT_IN_UBSAN_HANDLE_DYNAMIC_TYPE_CACHE_MISS_ABORT))
+ && call_expr_nargs (t) == 4)
+ return void_node;
+
+ return cxx_eval_builtin_function_call (old_call, t, allow_non_constant,
+ addr, non_constant_p, overflow_p);
+ }
hunk in it to ignore __builtin___ubsan_handle_dynamic_type_cache_miss*.
For fun == NULL_TREE, guess what you want is a switch on the CALL_EXPR_IFN
value and enumerate there all the internal calls and elsewhere builtins that
should be ignored.
