Re: [Minios-devel] [UNIKRAFT PATCH] lib/ukdebug: print DLVL_EXTRA messages only in debug build

[Simon Kuenzer <simon.kuenzer@xxxxxxxxx>]

Hey Yuri,

in general this is a feasible solution to enable selective debug 
messages, although I dislike the fact that it requires to manually 
modify the Makefiles.uk. But maybe we could add later a debug option 
into each libraries menu so that their Makefile.uk's set -D__UK_DEBUG__ 
by themselves. This way libraries could provide a menu option to 
enable/disable debugging.
Having this in mind I would change the behavior of this patch. I would 
actually add a bool option in ukdebug if debug messages should be on 
globally (default) or selective only. I would make this option 
independent of the chosen debug-verbosity-level. I think it is still a 
valuable option to select the verbosity-level even if you enable debug 
message printing only for a subset of libraries or objects.
This would even enable that libraries would not compile in the call to 
uk_printd() if they were unselected and global debugging is off.
What do you think?

On 18.07.2018 23:23, Yuri Volchkov wrote:
> At this point enabling LIBUKDEBUG_PRINTD_EXTRA does not help. You will
> be drowned with the output.
>
> Basically this became a real debug-level of message explicitness. So
> let's use it for debug purposes.
>
> With this patch, messages of DLVL_EXTRA will be printed ONLY if
> UK_DEBUG is defined. Now a developer can chose for which parts of
> Unikraft he wants an extra verbosity of the output, by adding a single
> line into the Makefile.uk.
>
> For example:
>      /* Enable for one lib */
>      LIBNAME_CFLAGS-y             += -DUK_DEBUG
>
>      /* Enable globally in Unikraft (brace yourself) */
>      CFLAGS-y                     += -DUK_DEBUG
>
> Signed-off-by: Yuri Volchkov <yuri.volchkov@xxxxxxxxx>
> ---
>   lib/ukdebug/Config.uk            |  2 +-
>   lib/ukdebug/include/uk/hexdump.h |  2 +-
>   lib/ukdebug/include/uk/print.h   | 16 ++++++++++++++--
>   3 files changed, 16 insertions(+), 4 deletions(-)
>
> diff --git a/lib/ukdebug/Config.uk b/lib/ukdebug/Config.uk
> index dcaeb3a..ff6279c 100644
> --- a/lib/ukdebug/Config.uk
> +++ b/lib/ukdebug/Config.uk
> @@ -24,7 +24,7 @@ choice
>           Set the level of detail of debug messages
>   
>   config LIBUKDEBUG_PRINTD_EXTRA
> -       bool "Show all types of debug messages"
> +       bool "Same as info + debug level messages (UK_DEBUG needs to be 
> defined)"
>   
>   config LIBUKDEBUG_PRINTD_INFO
>         bool "Show critical, error, warning, and information messages"
> diff --git a/lib/ukdebug/include/uk/hexdump.h b/lib/ukdebug/include/uk/hexdump.h
> index 4d32647..927769d 100644
> --- a/lib/ukdebug/include/uk/hexdump.h
> +++ b/lib/ukdebug/include/uk/hexdump.h
> @@ -92,7 +92,7 @@ void _uk_hexdumpd(int lvl, const char *libname, const char 
> *srcname,
>    */
>   #define uk_hexdumpd(lvl, data, len, flags, grps_per_line)                     
>  \
>         do {                                                                   \
> -               if ((lvl) <= DLVL_MAX)                                         \
> +               if (__ukdebug_is_printable_lvl(lvl))                           \
>                         _uk_hexdumpd((lvl), __STR_LIBNAME__, __STR_BASENAME__, \
>                                      __LINE__, (data), (len),                  \
>                                      ((size_t)(data)), (flags),                \
> diff --git a/lib/ukdebug/include/uk/print.h b/lib/ukdebug/include/uk/print.h
> index c5c5557..61e6bf6 100644
> --- a/lib/ukdebug/include/uk/print.h
> +++ b/lib/ukdebug/include/uk/print.h
> @@ -120,16 +120,28 @@ void _uk_printd(int lvl, const char *libname, const char 
> *srcname,
>   #define __STR_BASENAME__ (NULL)
>   #endif
>   
> +#ifdef UK_DEBUG
> +#define __uk_is_debug_lvl(lvl) (lvl <= DLVL_EXTRA)
> +#else
> +#define __uk_is_debug_lvl(lvl) (0)
> +#endif
> +
> +#if defined(UK_DEBUG) && DLVL_MAX == DLVL_EXTRA
> +#define __ukdebug_is_printable_lvl(lvl) (lvl <= DLVL_MAX)
> +#else
> +#define __ukdebug_is_printable_lvl(lvl) (lvl <= MIN(DLVL_MAX, DLVL_INFO))
> +#endif
> +
>   #define uk_vprintd(lvl, fmt, ap)                                              
>  \
>         do {                                                                   \
> -               if ((lvl) <= DLVL_MAX)                                         \
> +               if (__ukdebug_is_printable_lvl(lvl))                           \
>                         _uk_vprintd((lvl), __STR_LIBNAME__, __STR_BASENAME__,  \
>                                     __LINE__, (fmt), ap);                      \
>         } while (0)
>   
>   #define uk_printd(lvl, fmt, ...)                                               \
>         do {                                                                   \
> -               if ((lvl) <= DLVL_MAX)                                         \
> +               if (__ukdebug_is_printable_lvl(lvl))                           \
>                         _uk_printd((lvl), __STR_LIBNAME__, __STR_BASENAME__,   \
>                                    __LINE__, (fmt), ##__VA_ARGS__);            \
>         } while (0)
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