Philippe Mathieu-Daudé <philmd@xxxxxxxxxx> writes:
> On 10/25/21 07:25, Markus Armbruster wrote:
>> The generated visitor functions call visit_deprecated_accept() and
>> visit_deprecated() when visiting a struct member with special feature
>> flag 'deprecated'. This makes the feature flag visible to the actual
>> visitors. I want to make feature flag 'unstable' visible there as
>> well, so I can add policy for it.
>>
>> To let me make it visible, replace these functions by
>> visit_policy_reject() and visit_policy_skip(), which take the member's
>> special features as an argument. Note that the new functions have the
>> opposite sense, i.e. the return value flips.
>>
>> Signed-off-by: Markus Armbruster <armbru@xxxxxxxxxx>
>> ---
>> include/qapi/visitor-impl.h | 6 ++++--
>> include/qapi/visitor.h | 17 +++++++++++++----
>> qapi/qapi-forward-visitor.c | 16 +++++++++-------
>> qapi/qapi-visit-core.c | 22 ++++++++++++----------
>> qapi/qobject-input-visitor.c | 15 ++++++++++-----
>> qapi/qobject-output-visitor.c | 9 ++++++---
>> qapi/trace-events | 4 ++--
>> scripts/qapi/visit.py | 14 +++++++-------
>> 8 files changed, 63 insertions(+), 40 deletions(-)
>
>> diff --git a/qapi/qobject-input-visitor.c b/qapi/qobject-input-visitor.c
>> index 71b24a4429..fda485614b 100644
>> --- a/qapi/qobject-input-visitor.c
>> +++ b/qapi/qobject-input-visitor.c
>> @@ -662,16 +662,21 @@ static void qobject_input_optional(Visitor *v, const char *name, bool *present)
>> *present = true;
>> }
>>
>> -static bool qobject_input_deprecated_accept(Visitor *v, const char *name,
>> - Error **errp)
>> +static bool qobject_input_policy_reject(Visitor *v, const char *name,
>> + unsigned special_features,
>> + Error **errp)
>> {
>> + if (!(special_features && 1u << QAPI_DEPRECATED)) {
>
> Unreachable =) Proof than extract() is safer :P
Good eyes, thank you!
I actually like extract & desposit macros when the width is greater than
one. Then, the longhand C code is illegible anyway, and having to
remember what the macros mean is no worse.
For width 1 it feels like a wash. Universal use of the macros could
build familiarity and thus tip the balance.
I count more than a thousand instances of '& (1 <<'.
I wasn't even aware the macros existed in QEMU[*].
>
>> + return false;
>> + }
[*] I may well have seen them before, but my memory is limited and
lossy.
