Re: [PATCH v2 1/2] qom/object: add available_if field to TypeInfo

On 8/21/26 16:51, Pierrick Bouvier wrote:
> With the single-binary, we start mixing types for different targets,
> that may or may not be available for current one.
> 
> Previously, we implemented an approach based on interfaces, but it
> proved to be too limited. It requires duplication between
> machines/cpus/devices, and does not handle specific cases where a type
> should be available based on a target configuration (Kconfig).
> 
> To solve this, we add a new field, available_if, to TypeInfo.
> It is an array containing a list of requirements for type to be
> available.
> 
> For now, we have only targets as requirements, but later we'll add
> specific target config entries also.
> 
> We also add a TARGET_REQS macro, to declare a list of requirements. For
> sanity sake, we don't use a complex variadic macro prefixing each
> parameter. It requires a lot of macro boilerplate in C, and prevent
> readers to jump easily to definition for each parameter.
> 
> Signed-off-by: Pierrick Bouvier<[email protected]>
> ---
>   include/qemu/target-info.h | 11 +++++++++++
>   include/qom/object.h       |  5 +++++
>   qom/object.c               | 10 ++++++++++
>   rust/qom/src/qom.rs        |  1 +
>   stubs/meson.build          |  1 +
>   stubs/target-info.c        | 11 +++++++++++
>   target-info.c              | 13 +++++++++++++
>   7 files changed, 52 insertions(+)
>   create mode 100644 stubs/target-info.c
> 
> diff --git a/include/qemu/target-info.h b/include/qemu/target-info.h
> index 6c5b714288e..6379e65bbcf 100644
> --- a/include/qemu/target-info.h
> +++ b/include/qemu/target-info.h
> @@ -50,6 +50,17 @@ const char *target_cpu_type(void);
>    */
>   bool target_big_endian(void);
>   
> +typedef enum TargetReq {
> +    /* 0 is reserved for end of array */
> +    TARGET_REQ_BASE_ARM = 1,
> +    TARGET_REQ_AARCH64,
> +    TARGET_REQ_ARM,
> +} TargetReq;
> +

Is there a reason you're inventing Yet Another Enum, especially when target_base_arm etc 
are based on SysEmuTarget, which itself is used to create bitmasks of targets?


r~