On 9/21/25 12:13, Alyssa Ross wrote:
> Demi Marie Obenour <demiobenour@gmail.com> writes:
> 
>> On 9/21/25 04:55, Alyssa Ross wrote:
>>> Demi Marie Obenour <demiobenour@gmail.com> writes:
>>>
>>>> On 9/19/25 07:55, Alyssa Ross wrote:
>>>>> Demi Marie Obenour <demiobenour@gmail.com> writes:
>>>>>
>>>>>> This detected a missing prototype.
>>>>>>
>>>>>> No functional change.
>>>>>>
>>>>>> Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
>>>>>> ---
>>>>>>  tools/meson.build    | 2 ++
>>>>>>  tools/start-vmm/ch.h | 1 +
>>>>>>  2 files changed, 3 insertions(+)
>>>>>>
>>>>>> diff --git a/tools/meson.build b/tools/meson.build
>>>>>> index 9cebd03e323531fca7600cacf120161a98de16c5..8262f3e01d7bd56561306d7dd4650a22ca40ebe7 100644
>>>>>> --- a/tools/meson.build
>>>>>> +++ b/tools/meson.build
>>>>>> @@ -9,6 +9,8 @@ project('spectrum-tools', 'c',
>>>>>>    })
>>>>>>  
>>>>>>  add_project_arguments('-Wno-error=attributes', language : 'c')
>>>>>> +add_project_arguments('-Werror=missing-prototypes', language : 'c')
>>>>>> +add_project_arguments('-Werror=missing-declarations', language : 'c')
>>>>>>  
>>>>>>  if get_option('host')
>>>>>>    add_languages('rust')
>>>>>> diff --git a/tools/start-vmm/ch.h b/tools/start-vmm/ch.h
>>>>>> index 7230913ef0abf41a4f712ac4a543c7f7fdecec0f..5431365e6e2894cdebae22a9a44e2ccf1222e0d2 100644
>>>>>> --- a/tools/start-vmm/ch.h
>>>>>> +++ b/tools/start-vmm/ch.h
>>>>>> @@ -8,3 +8,4 @@ struct net_config {
>>>>>>  	char id[18];
>>>>>>  	uint8_t mac[6];
>>>>>>  };
>>>>>> +struct net_config net_setup(const char name[static 1], int name_len);
>>>>>
>>>>> Why do we need to declare this in a C header?  It's only used from Rust.
>>>>
>>>> Ideally the Rust declarations would be generated from the C ones
>>>> using bindgen.  Also, this catches genuine bugs on the C side.
>>>
>>> What bugs?  Implicit definitions are already disallowed, aren't they?
>>
>> Function declared in one file, defined in another file with different
>> prototype.  This makes it undefined behavior to call.
> 
> I don't see how this really enforces that?  Fundamentally the problem
> there is conflicting prototypes, not missing ones.  If you had another
> compilation unit that didn't include the header with the prototype, and
> instead make its own declaration, you'd still have the same problem.  If
> we have a norm of not declaring functions outside of the header file
> that corresponds to and is included by the implementation file, that
> prevents that from happening regardless of whether we have these errors,
> assuming that the compiler would still catch the prototype not matching
> the implementation.

It also catches cases where a function or variable should have been marked
static.
-- 
Sincerely,
Demi Marie Obenour (she/her/hers)