[dpdk-dev] [RFC v2] bus/auxiliary: introduce auxiliary bus

[Wang, Haiyue]

Hi Andrew,

> -----Original Message-----
> From: Thomas Monjalon <thomas at monjalon.net>
> Sent: Tuesday, June 8, 2021 15:53
> To: Xueming Li <xuemingl at nvidia.com>
> Cc: dev at dpdk.org; Parav Pandit <parav at nvidia.com>; Ray Kinsella <mdr at ashroe.eu>; Wang, Haiyue
> <haiyue.wang at intel.com>; andrew.rybchenko at oktetlabs.ru
> Subject: Re: [dpdk-dev] [RFC v2] bus/auxiliary: introduce auxiliary bus
> 


> > +
> > +/**
> > + * Match function for the driver to decide if device can be handled.
> > + *
> > + * @param name
> > + *   Pointer to the auxiliary device name.
> > + * @return
> > + *   Whether the driver can handle the auxiliary device.
> > + */
> > +typedef bool(*rte_auxiliary_match_t) (const char *name);
> 
> I disagree with the earlier comment asking for typedef pointer
> (based on one of my patches).
> Actually Andrew's suggestion makes sense:
> 	http://mails.dpdk.org/archives/dev/2021-June/210665.html
> 

I didn't get the error, but the same warning, I missed something ? ;-)

1. w/o pointer

#include <stdio.h>

typedef int (gpu_malloc_t)(void *dev, size_t size, void **ptr);

static gpu_malloc_t *mlx5_gpu_malloc_fn;

static int
mlx5_gpu_malloc(size_t size, void **ptr)
{
	return 0;
}

int main()
{
	mlx5_gpu_malloc_fn = mlx5_gpu_malloc;

	mlx5_gpu_malloc_fn(NULL, 0, NULL);

	return 0;
}


gcc -Wall fun.c
fun.c: In function 'main':
fun.c:15:21: warning: assignment to 'int (*)(void *, size_t,  void **)' {aka 'int (*)(void *, long unsigned int,  void **)'} from incompatible pointer type 'int (*)(size_t,  void **)' {aka 'int (*)(long unsigned int,  void **)'} [-Wincompatible-pointer-types]
   15 |  mlx5_gpu_malloc_fn = mlx5_gpu_malloc;
      |                     ^



2. w pointer

#include <stdio.h>

typedef int (*gpu_malloc_t)(void *dev, size_t size, void **ptr);

static gpu_malloc_t mlx5_gpu_malloc_fn;

static int
mlx5_gpu_malloc(size_t size, void **ptr)
{
	return 0;
}

int main()
{
	mlx5_gpu_malloc_fn = mlx5_gpu_malloc;

	mlx5_gpu_malloc_fn(NULL, 0, NULL);

	return 0;
}

gcc -Wall fun.c
fun.c: In function 'main':
fun.c:15:21: warning: assignment to 'gpu_malloc_t' {aka 'int (*)(void *, long unsigned int,  void **)'} from incompatible pointer type 'int (*)(size_t,  void **)' {aka 'int (*)(long unsigned int,  void **)'} [-Wincompatible-pointer-types]
   15 |  mlx5_gpu_malloc_fn = mlx5_gpu_malloc;
      |                     ^

>