Re: [PATCH] ell: Make public headers compilable with C++

From: Denis Kenzior <denkenz@gmail.com>
To: Brandon Cheo Fusi <fusibrandon13@gmail.com>, marcel@holtmann.org
Cc: ell@lists.linux.dev
Subject: Re: [PATCH] ell: Make public headers compilable with C++
Date: Sun, 30 Apr 2023 13:13:09 -0500	[thread overview]
Message-ID: <517bc712-06cf-98c2-c799-eda3d2a9db36@gmail.com> (raw)
In-Reply-To: <20230428122025.117834-1-fusibrandon13@gmail.com>

Hi Brandon,

On 4/28/23 07:20, Brandon Cheo Fusi wrote:
> This patch allows ell/ell.h to be included in C++ code by removing
> 'only C' features. These comprise
> 
> i)  implicit casts from void* to other types which are now made
>      explicit
> ii) C99 Static array indices.

<snip>

>   bool l_icmp6_client_set_address(struct l_icmp6_client *client,
> -					const uint8_t addr[static 6]);
> +					const uint8_t addr[]);

You can't really do that because l_icmp6_client_set_address implementation 
doesn't do any NULL/size checking.  It assumes an array of 6+ bytes.  And that 
is sort of the whole point of using the 'static 6' syntax.

Maybe there's a way to come up with an alternative declaration, using 
'__attribute__ nonnull'?  Perhaps combined with using a pointer to an array?

>   uint32_t l_rtnl_set_mac(struct l_netlink *rtnl, int ifindex,
> -					const uint8_t addr[static 6],
> +					const uint8_t addr[],
>   					bool power_up,
>   					l_netlink_command_func_t cb,
>   					void *user_data,

Same comments here.

Regards,
-Denis