On Tuesday, 28 October 2014 at 10:05:47 UTC, Robert burner
Schadek wrote:
On Tuesday, 28 October 2014 at 09:39:24 UTC, Martin Nowak wrote:
On Tuesday, 28 October 2014 at 08:38:50 UTC, Robert burner
Schadek wrote:
Actually, that is only true for LogLevel given to a log call
at runtime. calls to info, trace etc. are guarded with static
if.
So you're not paying any runtime overhead when calling log
functions with LogLevel build in their name.
If I cannot change the version identifiers that a library was
compiled with then the static if is always true. So you have to
perform the check at runtime. The only way around that is to
make
each library function that performs logging a template, be it
by
passing a Logger with CT LogLevel or by turning functions into
template functions so that the version identifiers leak into
the
library.
every log call is a template function or method already.
The latter is more fragile because the compiler might omit
instatiating a template or it might inline a function.
omitting the instantiation sound like undefined reference.
I don't see the problem with inlining. 1. there are no log
functions only log templates. 2. The version statement will
either leave empty template functions bodies, if(false) { ... }
template functions bodies, or template function bodies that
perform regular LogLevel checks on runtime LogLevel.
We're running in circles here. Lets find a new solution that
allows us to
* dmd -version=StdLoggerDisableLogLevel -- disable a LogLevel
at CT of user code
* that does not require a static Logger LogLevel
* does not leak version statements into phobos
* does not call log template functions where the LogLevel of
the version statement is part of the name, or at least yields
empty bodies for these template functions callls
Yep, let's try that.
I think part of the misunderstanding is that I'm thinking of an
app as user code plus a number of libraries all on top of phobos.
Say I have an app using vibe.d and I want to enable logging in my
app, but disable it in phobos.
Was it even a design goal that logging can be enabled on a per
library level?
