Implement building the repo for multiple configurations and architectures with a single command on Windows.

[jkoritzinsky]

This change allows developers to specify multiple configurations and architectures to build for in a single command by passing comma-separated lists to each parameter (PowerShell makes it comma separated instead of multiple instances of the option sadly). This feature is currently Windows only unless we also want to add support to the bash script.

For example:

./build -subset coreclr -a x64,arm,x86 -c debug,checked,release

This should enable users of the old ./src/coreclr/build.cmd all ... command to be able to generally keep their workflow when moving to the root script.

cc: @BruceForstall

[trylek]

Looks great, thank you!

[trylek]

Non-blocking nit: would it be possible, at least optionally, to somehow run these in parallel?

[jkoritzinsky]

I’ll check to see if Windows PowerShell supports that.

[BruceForstall]

IMO, this should be a follow-on change, if done.

[jkoritzinsky]

So there's ways to make it run in parallel, but I'm pretty sure that the restore process doesn't support being run in parallel so we'd likely end up with file locking issues during restore (since we'd have multiple different MSBuild processes running in parallel doing the same work).

[trylek]

I'm certainly not asking for implementing it in this PR, I'm just curious. I can easily imagine it's a more complex piece of work.

[BruceForstall]

Presumably the build process is already using maximum machine parallelism, right? At least the compile step is.

[BruceForstall]

Personally, I'd like it to always run through all the requested builds, and then report at the very end which ones failed. I'm ok with the current implementation that bails at the first failure, as a starter.

Question: this script is invoked from the root build.cmd. I think cmd.exe likes to eat argument commas, so does a comma-separated list make it to the ps1 file?

Request: update the "help" output to describe this new feature.

[jkoritzinsky]

Personally, I'd like it to always run through all the requested builds, and then report at the very end which ones failed. I'm ok with the current implementation that bails at the first failure, as a starter.

I can change it to run through all requested builds.

Question: this script is invoked from the root build.cmd. I think cmd.exe likes to eat argument commas, so does a comma-separated list make it to the ps1 file?

I went back and tested this again and although cmd doesn't eat the commas, it combines the arguments into one, so powershell sees the comma as part of an argument instead of as a list. I'll need to go figure out how to work around this.

Request: update the "help" output to describe this new feature.

Will do.

[akoeplinger]

This feature is currently Windows only unless we also want to add support to the bash script.

I'd love to have this in the bash version as well, especially for the Mono iOS/Android builds I'm working on cause I always need to build 3+ architectures there :)

[jkoritzinsky]

I'll take a look at adding this to the bash script as well after this PR gets in since it's a bit more complex (mainly because of deciding how to handle cross builds).

[BruceForstall]

I went back and tested this again and although cmd doesn't eat the commas, it combines the arguments into one, so powershell sees the comma as part of an argument instead of as a list. I'll need to go figure out how to work around this.

Example: if I have scripts x.bat:

call y.bat %*

and y.bat:

echo 1:%1 2:%2 3:%3 4:%4 5:%5

and run x -a x86,x64,arm, I see:

1:-a 2:x86 3:x64 4:arm 5:

The commas have disappeared.

[safern]

Should we somehow protect this logic in CI?

[jkoritzinsky]

I think the additional load on the machines/additional time for runs of runtime-live-build with testing this in CI is more expensive than the improvement it provides (since it's a relatively rarely used feature). There was never any CI validation of the equivalent feature in coreclr.