Re: [Qemu-devel] [PATCH v2 01/47] acpi: introduce AML composer aml_append()

[Michael S. Tsirkin]

> v.s. explicit headache of alloc/free, which doesn't fix
>      use-after-free anyway and just adds more boiler plate
>      plus makes code har to read read
> 
>   str = aml_alloc();
>   aml_string(str, "foo");
>   loc0 = aml_alloc();
>   aml_local(loc0, 0);
>   store = aml_alloc();
>   aml_store(store, str, loc0);
>   aml_append(method, store);
>   aml_free(store);
>   aml_free(loc0);
>   aml_free(str);

Looks like I wasn't clear.  This is what I propose:

void aml_add_method(AmlPool *pool, AmlBlob *aml)
{
   AmlBlob *str = aml_alloc(pool);
   aml_string(str, "foo");
   loc0 = aml_alloc(pool);
   aml_local(loc0, 0);
   AmlBob *store = aml_alloc(pool);
   aml_store(store, str, loc0);
   aml_append(method, store);
}


So just propagare AmlPool* everywhere, don't free.

Then at top level:

        AmlPool *pool = aml_pool_alloc();

        AmlSsdt = aml_add_ssdt(pool, ....);

        ....

        aml_pool_free(pool);



So from API perspective, this is very close to
what you posted, with just two changes:

        - pass pool parameter everywhere
        - have an extra alloc/free in only one place.

Happy?

-- 
MST