On Mon, Oct 13, 2025 at 06:16:05PM +0000, Zecheng Li wrote:
> When comparing types from different scopes, first compare their type
> offsets. A larger offset means the field belongs to an outer
> (enclosing) struct. This helps resolve cases where a pointer is found
> in an inner scope, but a struct containing that pointer exists in an
> outer scope. Previously, is_better_type would prefer the pointer type,
> but the struct type is actually more complete and should be chosen.
Wouldn't the size check be sufficient? I think we need to get read of
the pointer preference.
>
> Prefer types from outer scopes when is_better_type cannot determine
> a better type. This sometimes helps pick a more complete type.
This code has a loop for the scopes so detecting larger struct would
work well?
Thanks,
Namhyung
>
> Signed-off-by: Zecheng Li <zecheng@google.com>
> ---
> tools/perf/util/annotate-data.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c
> index 4b08331b9dd3..4b510eb29a5f 100644
> --- a/tools/perf/util/annotate-data.c
> +++ b/tools/perf/util/annotate-data.c
> @@ -1629,7 +1629,9 @@ static int find_data_type_die(struct data_loc_info *dloc, Dwarf_Die *type_die)
> pr_debug_dtp("type_offset=%#x\n", type_offset);
> }
>
> - if (!found || is_better_type(type_die, &mem_die)) {
> + if (!found || dloc->type_offset < type_offset ||
> + (dloc->type_offset == type_offset &&
> + !is_better_type(&mem_die, type_die))) {
> *type_die = mem_die;
> dloc->type_offset = type_offset;
> found = true;
> --
> 2.51.0.788.g6d19910ace-goog
>