Re: [Qemu-devel] [PATCH v3 4/8] tpm-backend: Made few interface methods optional

[Amarnath Valluri]

On 05/02/2017 03:29 PM, Marc-André Lureau wrote:
> On Tue, May 2, 2017 at 3:52 PM Amarnath Valluri 
> <address@hidden <mailto:address@hidden>> wrote:
>
>     This allows backend implementations left optional interface methods.
>     For mandatory methods assertion checks added.
>
>     Signed-off-by: Amarnath Valluri <address@hidden
>     <mailto:address@hidden>> 
>
>     ---
>      backends/tpm.c           | 24 ++++++++++++++++++------
>      hw/tpm/tpm_passthrough.c | 16 ----------------
>      2 files changed, 18 insertions(+), 22 deletions(-)
>
>     diff --git a/backends/tpm.c b/backends/tpm.c
>     index cf5abf1..8245426 100644
>     --- a/backends/tpm.c
>     +++ b/backends/tpm.c
>     @@ -48,7 +48,7 @@ const char *tpm_backend_get_desc(TPMBackend *s)
>      {
>          TPMBackendClass *k = TPM_BACKEND_GET_CLASS(s);
>
>     -    return k->ops->desc();
>     +    return k->ops->desc ? k->ops->desc() : "";
>      }
>
>
> If it only need to returns const, we may consider using a class field, 
> defaulting to null.
Yes, it makes more sense being a const member than a function pointer.
> Who is using it? tpm_backend_get_desc() not being called anywhere. 
> Let's remove it?
Frankly no one using this API, rather it's been accessed 
directly(be_drivers[i]->desc())  in tpm.c. It can be removed.

- Amarnath