Am Thu, 11 Sep 2014 21:32:44 +0000
schrieb "Robert burner Schadek" <[email protected]>:
> On Thursday, 11 September 2014 at 16:55:32 UTC, Marco Leise wrote:
> > 2. I noticed that as my logger implementation grew more complex
> > and used functionality from other modules I wrote, that if
> > these used logging as well I'd easily end up in a recursive
> > logging situation.
> >
> > Can recursion checks be added somewhere
> > before .writeLogMsg()?
>
> I think I don't follow. Just to clear
>
> foo() {
> log(); bar();
> }
>
> bar() {
> log(); foo();
> }
Let me clarify. Here is some code from 2015:
void main()
{
stdlog = new MyLogger();
// This call may overflow the stack if
// 'somethingBadHappened in someFunc():
error("ERROR!!!");
}
class MyLogger : Logger
{
override void writeLogMsg(ref LogEntry payload)
{
auto bla = someFunc();
useBlaToLog(bla, payload.msg);
}
}
// This is just some helper function unrelated to logging
// but it uses the stdlog functionality from Phobos itself
// as that is good practice in 2015.
auto someFunc()
{
...
if (somethingBadHappened)
{
// Now I must not be used myself in a logger
// implementation, or I overflow the stack!
error("something bad in someFunc");
}
...
}
> > 3. Exceptions and loggin don't mix.
> > Logging functions expect the file and line to be the one
> > where the logging function is placed. When I work with C
> > functions I tend to call them through a template that will
> > check the error return code. See:
> > http://dlang.org/phobos/std_exception.html#.errnoEnforce
> > Such templates pick up file and line numbers from where
> > they are instantiated and pass them on to the exception
> > ctor as runtime values.
> > Now when I use error(), I see no way to pass it runtime
> > file and line variables to make the log file reflect the
> > actual file and line where the error occured, instead of
> > some line in the template or where ever I caught the
> > exception.
> > Not all errors/exceptions are fatal and we might just want
> > to log an exception and continue with execution.
>
> hm, I think adding template function as requested by dicebot
> would solve that problem, as it would take line and friends as
> function parameters
How do you log errors that also throw exceptions ?
--
Marco
