Hi,

in a release-like build, I'm using the tharsis profiler, which is a
frame-based profiler. Zone is a RAII struct that measures how long its own
lifetime is.

    with (Zone(my_profiler, "zone name to appear in output")) {
        do_expensive_work();
        do_some_more_work();
    }
    // Zone goes out of scope here

I would like to use this code without modification in a release build
without profiling. I would rather not put version statements everywhere.
I have only one version statement in a single file that's included by
all files doing profiling:

    version (release_with_profiling) {
        public import tharsis.prof;
    }
    else {
        class Profiler { }
        struct Zone { this(Profiler, string) { } }
    }

Using that, the first code sample compiles in the non-profiling build,
where Zone is an empty struct.

*   Will the empty struct get optimized away completely by the compiler,
    at least if we pass -O -inline? I'd really like that, I have
    profiling code in several inner loops.

*   If not, what other approach could be usable to keep boilerplate in
    most source files to a minimum?

-- Simon

On Wednesday, 19 August 2015 at 09:54:33 UTC, SimonN wrote:
> Hi,

I've found this thread (Theoretical best practises):
http://forum.dlang.org/thread/codmadrwuyqxbklmuoiy@forum.dlang.org

My goal is the same; I'm only more wary of putting debug/version
everywhere. If the empty struct isn't optimized away fully,
I'd still be up for what's recommended in that thread.

-- Simon

On Wednesday, 19 August 2015 at 09:54:33 UTC, SimonN wrote:
> Hi,
>
> in a release-like build, I'm using the tharsis profiler, which is a
> frame-based profiler. Zone is a RAII struct that measures how long its own
> lifetime is.
>
>     with (Zone(my_profiler, "zone name to appear in output")) {
>         do_expensive_work();
>         do_some_more_work();
>     }
>     // Zone goes out of scope here
>
> I would like to use this code without modification in a release build
> without profiling. I would rather not put version statements everywhere.
> I have only one version statement in a single file that's included by
> all files doing profiling:
>
>     version (release_with_profiling) {
>         public import tharsis.prof;
>     }
>     else {
>         class Profiler { }
>         struct Zone { this(Profiler, string) { } }
>     }
>
> Using that, the first code sample compiles in the non-profiling build,
> where Zone is an empty struct.
>
> *   Will the empty struct get optimized away completely by the compiler,
>     at least if we pass -O -inline? I'd really like that, I have
>     profiling code in several inner loops.
>

I'd be surprised if it didn't, but you can always check the disassembly.
If for some reason either the compiler doesn't remove it (it never
removes classes btw but not sure about structs) or the linker
doesn't discard it you can try -gcsections ( or w/e its called ).

> *   If not, what other approach could be usable to keep boilerplate in
>     most source files to a minimum?
>
> -- Simon

On 2015-08-19 16:05, Nicholas Wilson wrote:

> I'd be surprised if it didn't, but you can always check the disassembly.
> If for some reason either the compiler doesn't remove it (it never
> removes classes btw but not sure about structs) or the linker
> doesn't discard it you can try -gcsections ( or w/e its called ).

I think the compiler still generates typeinfo for it.

-- 
/Jacob Carlborg