Re: [PATCH 2/3] dwarf_loader: Initial support for DW_TAG_subprogram in DW_TAG_enumeration

Alan Maguire
2026-03-30T09:05:38Z

On 23/03/2026 21:15, Arnaldo Carvalho de Melo wrote:
> From: Arnaldo Carvalho de Melo <acme@redhat.com>
>
> In Rust enums can have subprograms, add initial support for it.
>

I guess we'd need some form of enhanced enumerator kind to support this in BTF,
since I don't see any means to enhance the existing enumerator kind info to
support references to other type ids like functions.

> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Reviewed-by: Alan Maguire <alan.maguire@oracle.com>

> ---
> dwarf_loader.c | 38 ++++++++++++++++++++++++++++++--------
> 1 file changed, 30 insertions(+), 8 deletions(-)
>
> diff --git a/dwarf_loader.c b/dwarf_loader.c
> index f0833e8c44a944a8..b5a92160ecf82f74 100644
> --- a/dwarf_loader.c
> +++ b/dwarf_loader.c
> @@ -1943,6 +1943,8 @@ out_delete:
> return NULL;
> }
>
> +static struct tag *die__create_new_function(Dwarf_Die *die, struct cu *cu, struct conf_load *conf);
> +
> static struct tag *die__create_new_enumeration(Dwarf_Die *die, struct cu *cu, struct conf_load *conf)
> {
> Dwarf_Die child;
> @@ -1964,18 +1966,38 @@ static struct tag *die__create_new_enumeration(Dwarf_Die *die, struct cu *cu, st
>
> die = &child;
> do {
> - struct enumerator *enumerator;
> + switch (dwarf_tag(die)) {
> + case DW_TAG_enumerator: {
> + struct enumerator *enumerator = enumerator__new(die, cu, conf);
> +
> + if (enumerator == NULL)
> + goto out_delete;
> +
> + enumeration__add(enumeration, enumerator);
> + cu__hash(cu, &enumerator->tag);
> + }
> + continue;
> + case DW_TAG_subprogram: {
> + struct tag *tag = die__create_new_function(die, cu, conf);
> + uint32_t id;
> +
> + if (tag == NULL)
> + goto out_delete;
>
> - if (dwarf_tag(die) != DW_TAG_enumerator) {
> + if (cu__add_tag(cu, tag, &id) < 0) {
> + tag__delete(tag, cu);
> + goto out_delete;
> + }
> +
> + cu__hash(cu, tag);
> + struct dwarf_tag *dtag = tag__dwarf(tag);
> + dtag->small_id = id;
> + break;
> + }
> + default:
> cu__tag_not_handled(cu, die);
> continue;
> }
> - enumerator = enumerator__new(die, cu, conf);
> - if (enumerator == NULL)
> - goto out_delete;
> -
> - enumeration__add(enumeration, enumerator);
> - cu__hash(cu, &enumerator->tag);
> } while (dwarf_siblingof(die, die) == 0);
> out:
> return &enumeration->namespace.tag;