Is it possible to add optimization to remove unused  function arguments in binary generate ?

for example:

```d


void doWork(int args, string file, size_t line) {
    version(DEV_DEBUG) {
       Log.i("info from file %s line %d", file, line);
    }
   do_the_real_work();
}


void myApp(string file = __FILE__, size_t line = __LINE__){
    doWork(args, file, line);
}
```


when build without version DEV_DEBUG, the file and line is never used.  will ldc able to auto remove it from the binary code ?

On Saturday, 16 November 2019 at 04:22:17 UTC, Newbie2019 wrote:
>
> when build without version DEV_DEBUG, the file and line is never used.  will ldc able to auto remove it from the binary code ?

In general, no. Because the function signature must be obeyed such that the function can be called from anywhere without knowing the optimizations inside of it.
If the function is internal to a module and the function is not exported, then yes the optimization is perhaps legal. So LTO might be allowed (and able) to do it, but I don't know.

-Johan

On Saturday, 16 November 2019 at 11:25:35 UTC, Johan Engelen wrote:
> In general, no. Because the function signature must be obeyed such that the function can be called from anywhere without knowing the optimizations inside of it.
> If the function is internal to a module and the function is not exported, then yes the optimization is perhaps legal. So LTO might be allowed (and able) to do it, but I don't know.
>
> -Johan


most of them are internal to a module for debug.

Is LDC already do it, or could be done in  future?

On Sunday, 17 November 2019 at 06:42:48 UTC, Newbie2019 wrote:
> On Saturday, 16 November 2019 at 11:25:35 UTC, Johan Engelen wrote:
>> In general, no. Because the function signature must be obeyed such that the function can be called from anywhere without knowing the optimizations inside of it.
>> If the function is internal to a module and the function is not exported, then yes the optimization is perhaps legal. So LTO might be allowed (and able) to do it, but I don't know.
>>
>> -Johan
>
>
> most of them are internal to a module for debug.
>
> Is LDC already do it, or could be done in  future?

Already, just check in https://d.godbolt.org

This was asked a few months before:
https://forum.dlang.org/post/zuunbgthdschuncmaduo@forum.dlang.org

On Sunday, 17 November 2019 at 11:40:27 UTC, Boris Carvajal wrote:
>
> Already, just check in https://d.godbolt.org
>
> This was asked a few months before:
> https://forum.dlang.org/post/zuunbgthdschuncmaduo@forum.dlang.org


Thanks for the tips, I forget I has asked before.

So it only work if the target function is inlined ?