Golang cmd/go: allow all build flags for tool

Go version

latest

Output of `go env` in your module/workspace:

N/A

What did you do?

go tool .... <any number of flags>

What did you see happen?

The command supports on a very minimal set of flags (which are not documented, fwiw https://github.com/golang/go/issues/71502). All(?) other commands in the Go toolchain support a large range of flags to customize, troubleshoot, etc.

In particular, go run does, which feels like a very close parallel to go tool. It seems odd I can do -x to debug go run but not go tool, for instance.

What did you expect to see?

All build flags available.

Note: -n is in conflict, though.

Comment From: gabyhelp

Related Issues

cmd/go: missing flags in help output for tool #71502

Related Code Changes

cmd/go: document that go generate accepts all build flags

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Comment From: matloob

cc @ConradIrwin

I think this is reasonable to do, we'd just have to make sure we're adding the right set of flags. All we'd have to do is to call work.AddBuildFlags (with the appropriate BuildFlagMask).

Comment From: ConradIrwin

Seems reasonable to me; I didn't add them originally because it seemed out of scope (go tool --flag-flag-flag is no longer a useful time saver, and you're back to needing a wrapper script or be a one off).

That said, I don't see any downside

Comment From: matloob

@howardjohn do you have a use case for the flags other than -n and -x? Maybe we can start by just adding those?

I agree that the usefulness of providing several flags to go tool seems limited.

Comment From: seankhliao

you could maybe pass in build flags with GOFLAGS if necessary for debugging.