Re: [PATCH v2 11/18] qom: add object_new_with_class

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 12/9/19 4:01 PM, Paolo Bonzini wrote:
> Similar to CPU and machine classes, "-accel" class names are mangled,
> so we have to first get a class via accel_find and then instantiate it.
> Provide a new function to instantiate a class without going through
> object_class_get_name, and use it for CPUs and machines already.
> 
> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>   accel/accel.c             |  4 +---
>   include/qom/object.h      | 12 ++++++++++++
>   qom/object.c              |  5 +++++
>   target/i386/cpu.c         |  8 ++++----
>   target/s390x/cpu_models.c |  4 ++--
>   vl.c                      |  3 +--
>   6 files changed, 25 insertions(+), 11 deletions(-)
> 
> diff --git a/accel/accel.c b/accel/accel.c
> index 60c3827..dd38a46 100644
> --- a/accel/accel.c
> +++ b/accel/accel.c
> @@ -48,9 +48,7 @@ AccelClass *accel_find(const char *opt_name)
>   
>   int accel_init_machine(AccelClass *acc, MachineState *ms)
>   {
> -    ObjectClass *oc = OBJECT_CLASS(acc);
> -    const char *cname = object_class_get_name(oc);
> -    AccelState *accel = ACCEL(object_new(cname));
> +    AccelState *accel = ACCEL(object_new_with_class(OBJECT_CLASS(acc)));
>       int ret;
>       ms->accelerator = accel;
>       *(acc->allowed) = true;
> diff --git a/include/qom/object.h b/include/qom/object.h
> index 230b18f..f9ad692 100644
> --- a/include/qom/object.h
> +++ b/include/qom/object.h
> @@ -593,6 +593,18 @@ struct InterfaceClass
>                                                __FILE__, __LINE__, __func__))
>   
>   /**
> + * object_new_with_class:
> + * @klass: The class to instantiate.
> + *
> + * This function will initialize a new object using heap allocated memory.
> + * The returned object has a reference count of 1, and will be freed when
> + * the last reference is dropped.
> + *
> + * Returns: The newly allocated and instantiated object.
> + */
> +Object *object_new_with_class(ObjectClass *klass);

The function name bugs me... Pick your poison?

   object_new_by_class
   object_new_of_class
   object_new_for_class
   object_new_from_class
   object_new_with_class

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> +
> +/**
>    * object_new:
>    * @typename: The name of the type of the object to instantiate.
>    *
> diff --git a/qom/object.c b/qom/object.c
> index bfb4413..bc444d3 100644
> --- a/qom/object.c
> +++ b/qom/object.c
> @@ -658,6 +658,11 @@ static Object *object_new_with_type(Type type)
>       return obj;
>   }
>   
> +Object *object_new_with_class(ObjectClass *klass)
> +{
> +    return object_new_with_type(klass->type);
> +}
> +
>   Object *object_new(const char *typename)
>   {
>       TypeImpl *ti = type_get_by_name(typename);
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 69f518a..a044078 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -4640,7 +4640,7 @@ static void x86_cpu_class_check_missing_features(X86CPUClass *xcc,
>           return;
>       }
>   
> -    xc = X86_CPU(object_new(object_class_get_name(OBJECT_CLASS(xcc))));
> +    xc = X86_CPU(object_new_with_class(OBJECT_CLASS(xcc)));
>   
>       x86_cpu_expand_features(xc, &err);
>       if (err) {
> @@ -4711,7 +4711,7 @@ static GSList *get_sorted_cpu_model_list(void)
>   
>   static char *x86_cpu_class_get_model_id(X86CPUClass *xc)
>   {
> -    Object *obj = object_new(object_class_get_name(OBJECT_CLASS(xc)));
> +    Object *obj = object_new_with_class(OBJECT_CLASS(xc));
>       char *r = object_property_get_str(obj, "model-id", &error_abort);
>       object_unref(obj);
>       return r;
> @@ -5092,7 +5092,7 @@ static X86CPU *x86_cpu_from_model(const char *model, QDict *props, Error **errp)
>           goto out;
>       }
>   
> -    xc = X86_CPU(object_new(object_class_get_name(OBJECT_CLASS(xcc))));
> +    xc = X86_CPU(object_new_with_class(OBJECT_CLASS(xcc)));
>       if (props) {
>           object_apply_props(OBJECT(xc), props, &err);
>           if (err) {
> @@ -5936,7 +5936,7 @@ static void x86_cpu_apic_create(X86CPU *cpu, Error **errp)
>       APICCommonState *apic;
>       ObjectClass *apic_class = OBJECT_CLASS(apic_get_class());
>   
> -    cpu->apic_state = DEVICE(object_new(object_class_get_name(apic_class)));
> +    cpu->apic_state = DEVICE(object_new_with_class(apic_class));
>   
>       object_property_add_child(OBJECT(cpu), "lapic",
>                                 OBJECT(cpu->apic_state), &error_abort);
> diff --git a/target/s390x/cpu_models.c b/target/s390x/cpu_models.c
> index 7e92fb2..72cf48b 100644
> --- a/target/s390x/cpu_models.c
> +++ b/target/s390x/cpu_models.c
> @@ -440,7 +440,7 @@ static void create_cpu_model_list(ObjectClass *klass, void *opaque)
>       if (cpu_list_data->model) {
>           Object *obj;
>           S390CPU *sc;
> -        obj = object_new(object_class_get_name(klass));
> +        obj = object_new_with_class(klass);
>           sc = S390_CPU(obj);
>           if (sc->model) {
>               info->has_unavailable_features = true;
> @@ -501,7 +501,7 @@ static void cpu_model_from_info(S390CPUModel *model, const CpuModelInfo *info,
>           error_setg(errp, "The CPU definition '%s' requires KVM", info->name);
>           return;
>       }
> -    obj = object_new(object_class_get_name(oc));
> +    obj = object_new_with_class(oc);
>       cpu = S390_CPU(obj);
>   
>       if (!cpu->model) {
> diff --git a/vl.c b/vl.c
> index d6c77bc..f18b26b 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -3989,8 +3989,7 @@ int main(int argc, char **argv, char **envp)
>                         cleanup_add_fd, NULL, &error_fatal);
>   #endif
>   
> -    current_machine = MACHINE(object_new(object_class_get_name(
> -                          OBJECT_CLASS(machine_class))));
> +    current_machine = MACHINE(object_new_with_class(OBJECT_CLASS(machine_class)));
>       if (machine_help_func(qemu_get_machine_opts(), current_machine)) {
>           exit(0);
>       }
>