Re: [PATCH proxmox v5 03/21] api-macro: support #[state] attribute for state injection

["Lukas Wagner" <l.wagner@proxmox.com>]

On Thu Sep 3, 2026 at 8:51 PM CEST, Michael Köppl wrote:
> On Thu Sep 3, 2026 at 1:15 PM CEST, Lukas Wagner wrote:
>
> [snip]
>
>>  fn handle_function_signature(method_info: &mut MethodInfo) -> Result<Ident, Error> {
>> +    let state_params = take_state_attributes(&mut method_info.func.sig);
>> +
>>      let sig = &method_info.func.sig;
>>  
>>      let mut api_method_param = None;
>> @@ -382,7 +474,11 @@ fn handle_function_signature(method_info: &mut MethodInfo) -> Result<Ident, Erro
>>  
>>      let mut param_list = Vec::<(FieldName, ParameterType)>::new();
>>  
>> -    for input in sig.inputs.iter() {
>> +    for (index, input) in sig.inputs.iter().enumerate() {
>> +        if state_params.contains(&index) {
>> +            continue;
>> +        }
>
> Even though it's not something that would likely occur (since this would
> e.g. occur if someone used `#[state] _: PdmApplication` or something
> similar), this would not show any errors from checking the types
> anymore, no? Because the second [loop] expects errors to be handled
> [here], but for state params, this check would simply be skipped. Hope
> I'm not missing something here, but this would probably hide errors.
>

Good thinking!

I tried various patterns, such as 

#[state] _: A
#[state] A(inner): A
#[state] B {inner}: B

and they don't work with the API macro, it seems to trip up somewhere
else - so the issue you described does not seem to matter here.

Now, the next question is, should these patterns work for #[state]
arguments? Probably fine if they don't, but long-term we could think
about supporting these - at least the last two could be handy in some
cases. But we'll probably get by fine without them.

>> +
>>          let (pat_type, pat) = match check_input_type(input) {
>>              Ok(input) => input,
>>              Err(err) => {
>
> [here]
>
>> @@ -410,7 +506,7 @@ fn handle_function_signature(method_info: &mut MethodInfo) -> Result<Ident, Erro
>>          };
>>      }
>>  
>> -    for input in sig.inputs.iter() {
>> +    for (index, input) in sig.inputs.iter().enumerate() {
>>          let (pat_type, pat) = match check_input_type(input) {
>>              Ok(input) => input,
>>              Err(_err) => continue, // we already produced errors above,
>
> [loop]
>
>> @@ -421,17 +517,20 @@ fn handle_function_signature(method_info: &mut MethodInfo) -> Result<Ident, Erro
>>          // values, and our 2 fixed function parameters: `&ApiMethod` and `&mut dyn RpcEnvironment`.
>>          //
>>          // Our strategy is as follows:
>> -        //     1) See if the parameter name also appears in the input schema. In this case we
>> +        //     1) See if the parameter was marked with `#[state]`. Such parameters are filled in
>
> [snip]