Re: [PATCH v2] symbol: preserve address space qualifiers with typeof()

[Chris Li <sparse@chrisli.org>]

Hi Dan,

Thanks for the patch. Sorry for the late reply. Super busy recently.
Now I am back and catching up on my back logs.

On Tue, Oct 28, 2025 at 5:06 PM Dan Carpenter <dan.carpenter@linaro.org> wrote:
>
> When we're parsing typeof(var) we then preserve the address space
> qualifiers as well.  Otherwise it leads to warnings like this:
>
> "warning: cast removes address space '__seg_gs' of expression"
>
> Reported-by: Uros Bizjak <ubizjak@gmail.com>
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>

Your patch makes one of the known to fail tests passed. I took the
liberty to add the following change to make validation check happy:
diff --git a/validation/typeof-addresspace.c b/validation/typeof-addresspace.c
index a94f77a3..34ac3089 100644
--- a/validation/typeof-addresspace.c
+++ b/validation/typeof-addresspace.c
@@ -16,5 +16,4 @@ static void test_as(void)

 /*
  * check-name: typeof-addresspace.c
- * check-known-to-fail
  */

Applied to sparse-dev.

Chris

> ---
> v2: Fix a NULL dereference because "base" can be NULL.  Sorry for not
> running the validation/ tests...  :(
>
>  symbol.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/symbol.c b/symbol.c
> index 7060acb666d9..a42289226650 100644
> --- a/symbol.c
> +++ b/symbol.c
> @@ -544,9 +544,12 @@ static struct symbol *examine_pointer_type(struct symbol *sym)
>  static struct symbol *examine_typeof_helper(struct symbol *sym, bool qual)
>  {
>         struct symbol *base = evaluate_expression(sym->initializer);
> +       struct ident *as = NULL;
>         unsigned long mod = 0;
>
> -       if (!base)
> +       if (base)
> +               as = base->ctype.as;
> +       else
>                 base = &bad_ctype;
>         if (base->type == SYM_NODE) {
>                 mod |= base->ctype.modifiers & MOD_TYPEOF;
> @@ -559,6 +562,8 @@ static struct symbol *examine_typeof_helper(struct symbol *sym, bool qual)
>         sym->type = SYM_NODE;
>         sym->ctype.modifiers = mod;
>         sym->ctype.base_type = base;
> +       if (qual)
> +               sym->ctype.as = as;
>         return examine_node_type(sym);
>  }
>
> --
> 2.51.0
>