Re: [PATCH 24/25] dynamic_debug: drop pr_fmt() from dynamic_pr_debug

Jim Cromie
2011-07-26T05:55:26Z

On Mon, Jul 25, 2011 at 9:45 PM, Joe Perches <joe@perches.com> wrote:
> On Mon, 2011-07-25 at 15:42 -0600, Jim Cromie wrote:
>> dynamic_pr_debug can add module, function, file, and line selectively,
>> theres no need to also add them via macro.  Moreover, adding them
>> via the macro, which is useful for pr_info and friends, causes
>> pr_debug to double-print those fields added by the flag-settings.
> []
>> -             __dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__);\
>> +             __dynamic_pr_debug(&descriptor, fmt, ##__VA_ARGS__);    \
>
> Hey Jim.
>
> Thinking about a bit more, maybe it's possible to use
> another test to see if the current pr_fmt is:
>
> #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>
> and not add pr_fmt when appropriate.
>
> I tried this once.  I recall it worked without adding any
> new string dependencies.   It did depend on __builtin_strcmp.
>
> +#define _first_macro_arg(arg1, args...) arg1
> +#define first_macro_arg(arg1, args...) _first_macro_arg(arg1)
> +
> +#define define_kernel_printk_level(level, fmt, ...)                    \
> +do {                                                                   \
> +       if (__builtin_strcmp(first_macro_arg(pr_fmt(fmt)),              \
> +                            KBUILD_MODNAME ": " fmt))                  \
> +               printk(level pr_fmt(fmt), ##__VA_ARGS__);               \
> +       else                                                            \
> +               printk(level fmt, ##__VA_ARGS__);                       \
> +} while (0)
>
>
>
>

hi Joe,

In case it wasnt clear, the idea was to leave pr_fmt as is for use
with pr_info, etc.
Providing another, separate macro for the purpose would seem most
straightforward:

#define pr_dbg_fmt ( fmt ) fmt

>> - __dynamic_pr_debug(&descriptor, pr_fmt(fmt), ##__VA_ARGS__);\
>> + __dynamic_pr_debug(&descriptor, pr_dbg_fmt(fmt), ##__VA_ARGS__); \

would this address your concerns ?

It doesnt allow arbitrary insertion of extra punctuation, etc between
file, func, module, line, nor rearrange the ordering, but thats
probably overkill.