Hi Guys,

CTFE not being in coverage reports has made 100% coverage unattainable
for code which has if (__ctfe) branches.

Well fret no more.
A few hours ago I've gotten this result.

---
      4|int f(int n) { int acc;
     42|    foreach(i;0 .. n)
       |    {
     10|        acc += i;
       |    }
      4|    return acc;
       |}
       |
       |
       |pragma(msg, f2(4));
       |pragma(msg, f(4));
       |pragma(msg, f2(4));
       |
       |void main()
       |{
       |    import core.stdc.stdio;
      1|    printf("%d %d %d\n", f(1), f(2), f(3));
       |}
       |
       |int f2(int n)
       |{
      2|    int acc;
     30|    foreach(i;0 .. n)
       |    {
      8|        acc += i;
       |    }
      2|    return acc;}
test_ctfe.d is 100% covered
---

the function f2() is never called at runtime at yet we are 100% covered.

The way it works is quite simple.
During CTFE we keep an array which counts the lines we hit.
When it comes time to do codegen we simply initialize the hidden __coverge symbol.
Which is a uint[]  representing the coverage counts for line numbers with that information rather than filling it with zeros.

Therefore no modification to the runtime is necessary at all.

It's open as DMD pr: https://github.com/dlang/dmd/pull/11279

and hopefully passing on all platforms.

Cheers,

Stefan

On Monday, 15 June 2020 at 15:02:04 UTC, Stefan Koch wrote:
> Hi Guys,
>
> CTFE not being in coverage reports has made 100% coverage unattainable
> for code which has if (__ctfe) branches.
>
> Well fret no more.

[snip of code demonstrating the improvement, better coverage stats]

>
>
> The way it works is quite simple.
> During CTFE we keep an array which counts the lines we hit.
> When it comes time to do codegen we simply initialize the hidden __coverge symbol.
> Which is a uint[]  representing the coverage counts for line numbers with that information rather than filling it with zeros.
>
> Therefore no modification to the runtime is necessary at all.
>
> It's open as DMD pr: https://github.com/dlang/dmd/pull/11279
>
> and hopefully passing on all platforms.
>
> Cheers,
>
> Stefan

Thanks for this Stefan.  Another nice step towards "it all just works" and a commendably simple implementation.

On Monday, 15 June 2020 at 16:49:16 UTC, Bruce Carneal wrote:
> On Monday, 15 June 2020 at 15:02:04 UTC, Stefan Koch wrote:
>> Hi Guys,
>>
>> CTFE not being in coverage reports has made 100% coverage unattainable
>> for code which has if (__ctfe) branches.
>> 
>> Fret no mre.
>>
>> Stefan
>
> Thanks for this Stefan.  Another nice step towards "it all just works" and a commendably simple implementation.

Thanks Bruce, it does help tremendously to get this kind of feedback.

Cheers,
Stefan

P.S. let's meet at  the online beerconf, if and when it happnes.

On 6/15/20 10:11 AM, Stefan Koch wrote:

> it does help tremendously to get this kind of feedback.

Sorry for being quiet but I always appreciate your work. It's inspring how you never give up and continue going forward. :)

Ali

On Monday, 15 June 2020 at 18:49:01 UTC, Ali Çehreli wrote:
> On 6/15/20 10:11 AM, Stefan Koch wrote:
>
> > it does help tremendously to get this kind of feedback.
>
> Sorry for being quiet but I always appreciate your work. It's inspring how you never give up and continue going forward. :)
>
> Ali

Same here. Stefan rox.

On Monday, 15 June 2020 at 20:00:55 UTC, Max Samukha wrote:
> On Monday, 15 June 2020 at 18:49:01 UTC, Ali Çehreli wrote:
>> On 6/15/20 10:11 AM, Stefan Koch wrote:
>>
>> > it does help tremendously to get this kind of feedback.
>>
>> Sorry for being quiet but I always appreciate your work. It's inspring how you never give up and continue going forward. :)
>>
>> Ali
>
> Same here. Stefan rox.

Thank you both Ali and Max.

On 2020-06-15 19:11, Stefan Koch wrote:
> On Monday, 15 June 2020 at 16:49:16 UTC, Bruce Carneal wrote:
>> On Monday, 15 June 2020 at 15:02:04 UTC, Stefan Koch wrote:
>>> Hi Guys,
>>>
>>> CTFE not being in coverage reports has made 100% coverage unattainable
>>> for code which has if (__ctfe) branches.
>>>
>>> Fret no mre.
>>>
>>> Stefan
>>
>> Thanks for this Stefan.  Another nice step towards "it all just works" and a commendably simple implementation.
> 
> Thanks Bruce, it does help tremendously to get this kind of feedback.
> 
> Cheers,
> Stefan
> 
> P.S. let's meet at  the online beerconf, if and when it happnes.

Stefan, let me then add that I always look up to your work.
Become one of the greats! ;)

On Monday, 15 June 2020 at 17:11:25 UTC, Stefan Koch wrote:
> On Monday, 15 June 2020 at 16:49:16 UTC, Bruce Carneal wrote:

>> Thanks for this Stefan.  Another nice step towards "it all just works" and a commendably simple implementation.
>
> Thanks Bruce, it does help tremendously to get this kind of feedback.

How to know that you did great work: nobody is saying anything, everybody's just using it ;)

Keep rocking!

On Monday, 15 June 2020 at 15:02:04 UTC, Stefan Koch wrote:
> Hi Guys,
>
> CTFE not being in coverage reports has made 100% coverage unattainable
> for code which has if (__ctfe) branches.
>
> Well fret no more.
> A few hours ago I've gotten this result.
>

D has no much potential to take on so many different domains. Moving programming challenges to compile time creates some unique opportunity.

It is nice to hear about your progress.

On Monday, 15 June 2020 at 20:51:13 UTC, Faux Amis wrote:
> On 2020-06-15 19:11, Stefan Koch wrote:
>> On Monday, 15 June 2020 at 16:49:16 UTC, Bruce Carneal wrote:
>>> On Monday, 15 June 2020 at 15:02:04 UTC, Stefan Koch wrote:
>>>> Hi Guys,
>>>>
>>>> CTFE not being in coverage reports has made 100% coverage unattainable
>>>> for code which has if (__ctfe) branches.
>>>>
>>>> Fret no mre.
>>>>
>>>> Stefan
>>>
>>> Thanks for this Stefan.  Another nice step towards "it all just works" and a commendably simple implementation.
>> 
>> Thanks Bruce, it does help tremendously to get this kind of feedback.
>> 
>> Cheers,
>> Stefan
>> 
>> P.S. let's meet at  the online beerconf, if and when it happnes.
>
> Stefan, let me then add that I always look up to your work.
> Become one of the greats! ;)

Thanks.
I am happy you think so.