On 2020/4/22 下午4:26, Marek Behun wrote:
> On Wed, 22 Apr 2020 14:49:46 +0800
> Qu Wenruo <wqu@suse.com> wrote:
> 
>> +/* A simple wraper to for error() from btrfs-progs */
>> +#define error(...) { printf(__VA_ARGS__); printf("\n"); }
> 
> Is this from btrfs-progs?

Nope, anything in compat.h is mostly for different projects to share the
same code.

> I don't like these macros much, I prefer to use static inline functions.
> 
> static inline void error(const char *fmt, ...)
> {
> 	printf(fmt, __builtin_va_arg_pack());
> 	printf("\n");
> }

That looks much better, especially we can tell compiler that we want
printf check on the parameters.

Thanks,
Qu

> 
> Attribute for printf can be added to check printf specifiers:
>   __attribute__((format (__printf__, 1, 2)))
> 
> It is possible that this won't compile when optimizations are disabled.
> In that case more attributes are needed
>   __always_inline __attribute__((__gnu_inline__))
> These could be defined as a macro in include/linux/compiler-gcc.h
>   #define __gnu_inline __always_inline __attribute__((__gnu_inline__))
> 
> Marek
>