LogVHdrMessageVerb allows a custom header to be inserted in a log message,
between the Log system's MessageType string, and a formatted variable
message body. The custom header can itself be a formatted variable string.
These functions can be used, for example, by driver abstraction layers to
format specific driver messages in a standard format, but do it in a way
that is efficient, obeys the log-layers verbosity settings, and is safe
to use in signal handlers (because they don't call malloc), even for
types besides X_NONE.
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>