[CMAKE] Enable multithreaded compilation for VC6 builds

[aliendroid1]

Created a custom cmake toolchain file for using the vc6 compiler with the ninja generator

Switching from nmake to multithreaded ninja reduces compile times by an order of magnitude

[Mauller]

I would make this as an alternative build method instead of a replacement since we still need PDB files when debugging crashes.

[aliendroid1]

I would make this as an alternative build method instead of a replacement since we still need PDB files when debugging crashes.

It still has embedded debug information

[xezon]

@OmniBlade What are your thoughts on this?

[OmniBlade]

There is a lot of none functional change in the json files which could do with being reverted. No averse to an autoformatted file, but it should be applied in a separate PR.

[OmniBlade]

Just checked in VSCode and the way its formatted now is the way it gets autoformatted there, so I think I'd need a good case made for changing how its formatted?

[aliendroid1]

I would make this as an alternative build method instead of a replacement since we still need PDB files when debugging crashes.

It seems to create a pdb even if debug information format is set to null

[Caball009]

Combined with #1210 this provides a huge improvement for VC6 build times for me.

[xezon]

All vc6 targets are failing with CMake Error: Error: generator : Ninja

How do we get this Ninja locally then?

[aliendroid1]

All vc6 targets are failing with CMake Error: Error: generator : Ninja

How do we get this Ninja locally then?

Maybe you don't have ninja in your environment variables or haven't installed it?
https://ninja-build.org/
I do plan to update it to ninja multiconfig in a follow up pr once this one is merged

[xezon]

I do not have it yes and CI is also failing for it. Should this perhaps be a new preset?

[aliendroid1]

I do not have it yes and CI is also failing for it. Should this perhaps be a new preset?

The ci actually doesn't fail for it. It is only failing because delete cache needs to be run once but if I change the binary directory to a new one then it passes. Just download ninja. Look at the bottom of the link I sent

[xezon]

How do we delete build cache?

[aliendroid1]

How do we delete build cache?

I just click delete cache and reconfigure under Project in visual studio

[xezon]

So how do we fix the CI failing builds? And what can we do for users that do not yet use Ninja?

[aliendroid1]

With #1210 the visual studio ninja will be used automatically when using cmake inside visual studio. Plus our wiki already tells people to install ninja. They can also add the path to their version of ninja to the environment variiable. I'll try see if detection of ninja can be done in a .cmake file

As for the CI, I would look into it except I don't have access to submit a pr that modifies the CI. We just need to update the cache it uses

[aliendroid1]

With #1210 the visual studio ninja will be used automatically when using cmake inside visual studio. Plus our wiki already tells people to install ninja. They can also add the path to their version of ninja to the environment variiable. I'll try see if detection of ninja can be done in a .cmake file

As for the CI, I would look into it except I don't have access to submit a pr that modifies the CI. We just need to update the cache it uses

we could add something like "CMAKE_MAKE_PROGRAM": "C:/PROGRA1/MICROS2/2022/COMMUN1/Common7/IDE/COMMON1/MICROS~1/CMake/Ninja/ninja.exe" to cache variables but then that would force using the ninja in visual studio 2022

[aliendroid1]

With #1210 the visual studio ninja will be used automatically when using cmake inside visual studio. Plus our wiki already tells people to install ninja. They can also add the path to their version of ninja to the environment variiable. I'll try see if detection of ninja can be done in a .cmake file

As for the CI, I would look into it except I don't have access to submit a pr that modifies the CI. We just need to update the cache it uses

nvm I do have access. I just happened to be using an access token that didn't have the right permissions

[aliendroid1]

So how do we fix the CI failing builds? And what can we do for users that do not yet use Ninja?

CI is now fixed

[OmniBlade]

Looks good, works locally for me. Good spot on being able to limit the linker to one concurrent run, that did indeed fix the issue I had trying to link concurrently with VC6. Before merge I would like clarification on if the compiler pools are required or if you can just leave that unspecified and let ninja determine the max pool size.

With this there doesn't appear to be much difference between VC6 and win32 presets, perhaps they should be merged into a single preset now that will vary only based on the environment they are run in.

[xezon]

This change is amazing. VC6 compile time is incredible. Under 1 minute on my system. Can we have the same compile speed for VS 2022 builds as well?

Fyi, to use, I downloaded Windows Ninja from https://ninja-build.org/, extracted the ninja.exe into a folder, put it into Path environment variable, and then reconfigured CMake for VC6 builds.

[aliendroid1]

This change is amazing. VC6 compile time is incredible. Under 1 minute on my system. Can we have the same compile speed for VS 2022 builds as well?

Fyi, to use, I downloaded Windows Ninja from https://ninja-build.org/, extracted the ninja.exe into a folder, put it into Path environment variable, and then reconfigured CMake for VC6 builds.

I'm actually quite puzzled on why vs 2022 builds are so much slower even though they also use ninja. My guess is that its due to the way thread safety is setup but I will investigate

[xezon]

Hmm on my machine it uses MSBuild.exe I think.

[aliendroid1]

Hmm on my machine it uses MSBuild.exe I think.

Do you set the generator to visual studio?

[xezon]

Yes

[aliendroid1]

Yes

Then that's why. For vc6 as well if I use the visual studio generator then it's significantly slower than with ninja. Ninja in general is a really fast build tool.

[aliendroid1]

Looks good, works locally for me. Good spot on being able to limit the linker to one concurrent run, that did indeed fix the issue I had trying to link concurrently with VC6. Before merge I would like clarification on if the compiler pools are required or if you can just leave that unspecified and let ninja determine the max pool size.

With this there doesn't appear to be much difference between VC6 and win32 presets, perhaps they should be merged into a single preset now that will vary only based on the environment they are run in.

Most the stuff can be extractedd into a common preset for them to inherit from but if we make them a single preset then they would use the same binary directory and that would make force having to delete the entire build directory rebuild cache every time we want to switch from building one to the other