If configured with PatternLayout, Log::Log4perl will use Perl's
caller($depth) function internally to obtain the name of the
function/method where the logging statement is located in at runtime.
Since caller($depth) returns "(eval)" as the
subroutine name if you're within an eval {}, Log::Log4perl will
display "(eval)".
There's a nasty trick you could use to bump up the caller level and
have it return the calling function:
use Log::Log4perl qw(:easy);
Log::Log4perl->easy_init(
{ level => $DEBUG,
layout => "%M: %m%n",
});
foo();
sub foo {
eval {
local $Log::Log4perl::caller_depth =
$Log::Log4perl::caller_depth + 1;
DEBUG("I'm here!");
};
}
This will print
main::foo: I'm here!
as expected. However, there's several things to consider:
-
Don't forget to set back the caller level to the previous value when
you're exiting the eval {} construct (the 'local' takes care of that).
-
This will only go back one level. If you've got nested eval's, it's
not going to go up to the calling function.
- Not only the reported function name will be affected this way, but also items like the line number (%L) or file name (%F) will reflect the location of the calling function, not the Log::Log4perl logger call.
-
It's not really clean for the application to fiddle around with
Log::Log4perl's internals. The next version of Log::Log4perl is
rumoured (mutter, mutter, ...) to take care of this issue
automagically.
Check the log4perl-devel@lists.sourceforge.net mailing list for updates.