[PATCH] handle sanitizer built-ins in -Wuninitialized (PR 101300)

[Bernhard Reutner-Fischer]

On Fri, 2 Jul 2021 13:21:10 -0600
Martin Sebor via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:

> --- a/gcc/tree-ssa-uninit.c
> +++ b/gcc/tree-ssa-uninit.c
> @@ -228,9 +228,26 @@ check_defs (ao_ref *ref, tree vdef, void *data_)
>    gimple *def_stmt = SSA_NAME_DEF_STMT (vdef);
>  
>    /* The ASAN_MARK intrinsic doesn't modify the variable.  */
> -  if (is_gimple_call (def_stmt)
> -      && gimple_call_internal_p (def_stmt, IFN_ASAN_MARK))
> -    return false;
> +  if (is_gimple_call (def_stmt))
> +    {
> +      if (gimple_call_internal_p (def_stmt)
> +         && gimple_call_internal_fn (def_stmt) == IFN_ASAN_MARK)
> +       return false;
> +
> +      if (tree fndecl = gimple_call_fndecl (def_stmt))
> +       {
> +         /* Some sanitizer calls pass integer arguments to built-ins
> +            that expect pointets. Avoid using gimple_call_builtin_p()

pointers

What happened to the suspicion that the fnspec attribs are
allegedly not correct (
https://gcc.gnu.org/legacy-ml/gcc-patches/2018-02/msg00541.html )?

Wouldn't that deal with this issue transparently if additionally the
args were passed in correctly?
Didn't follow *san closely though.

thanks,

> +            which fails for such calls.  */
> +         if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
> +           {
> +             built_in_function fncode = DECL_FUNCTION_CODE (fndecl);
> +             if (fncode > BEGIN_SANITIZER_BUILTINS
> +                 && fncode < END_SANITIZER_BUILTINS)
> +               return false;
> +           }
> +       }
> +    }
>