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tools: track tools/tooling updates to support generics #50558

Open findleyr opened 2 years ago

findleyr commented 2 years ago

Many tools and libraries that operate on Go code need to be updated to support generics. In most cases, this requires handling of the new constructs introduced in go/ast and go/types.

This is a tracking issue for the status of this support. It is based on #24661, which did the same for modules, though I added several tools/packages, and removed any that have been archived or that don't work directly with Go code.

It is not the case that every tool listed here needs updates to support generics -- many will require no changes. However, any tool that interacts with Go code might need to be updated, and probably needs additional tests.

Issue #50447 tracks adding a transitional API + user guide that should make it easier to get started updating third-party tools.

How to Help

List of tools / packages

mvdan commented 2 years ago

I think the gogrep entry is a bit confusing :) The link doesn't point to a Go analysis tool, and the linked issue is about support for modules. Also, note that the actual repo has been archived, so I think we can just omit it entirely, unless there's a healthy fork somewhere.

For gofumpt, I think it already supports type parameters (https://github.com/mvdan/gofumpt/blob/ba9bdf90c2757f830763edbfb9ab401a50012fa8/testdata/scripts/typeparams.txt), so we can probably mark it as done unless there's a specific bug or missing feature you can point me to.

findleyr commented 2 years ago

I think the gogrep entry is a bit confusing :)

Whoops! I started with the list from #24661, and missed that link. I removed the gogrep item, and marked gofumpt as done. Thanks!

mvdan commented 2 years ago

In terms of the other tools, you already mentioend https://github.com/golang/go/issues/50447, and I think https://github.com/golang/go/issues/48525 also deserves a mention as a blocker. Some static analysis tools, like unparam or staticcheck, depend on SSA.

thepudds commented 2 years ago

Hi @findleyr One thing that might be helpful is a pointer to a body of generic Go code to test against?

For example, I've pitched in a bit on dvyukov/go-fuzz, and I've confirmed that a hello world generic target seems to work, but I suspect more complicated examples might have problems. A while ago, I pulled together a small set of generics examples, but probably not representative enough, and it might be helpful to have a pointer here to a good set of examples.

Also, in case you haven't already seen this, there is a list of ~80 utilities here in https://github.com/golangci/golangci-lint/pull/2438#issue-1090001715 with some high-level status for generics support, including red X's for "known to panic on generic code".

nevkontakte commented 2 years ago

https://github.com/gopherjs/gopherjs/issues/1013 is the specific issue that tracks Generics support in GopherJS.

zephyrtronium commented 2 years ago

@thepudds

Hi @findleyr One thing that might be helpful is a pointer to a body of generic Go code to test against?

The test cases in test/typeparam might be useful for that.

findleyr commented 2 years ago

@thepudds thank you! Sorry for the slow turnaround: I will incorporate that list along with what I know about x/tools analyzers.

Regarding a corpus of generic code: @zephyrtronium's suggestion of test/typeparam is good. I also sometimes use go/types/testdata/examples. But the point stands: I think we should perhaps consider including a small corpus in the soon-to-be-created x/exp/typeparams module.

ipfans commented 2 years ago

Due to golangci-lint v1.45.0 being released, I think its status is now supported.

findleyr commented 2 years ago

Thanks @ipfans -- I updated to note that golangci-lint has partial generics support.

mvdan commented 2 years ago

Regarding a corpus of generic code: @zephyrtronium's suggestion of test/typeparam is good. I also sometimes use go/types/testdata/examples. But the point stands: I think we should perhaps consider including a small corpus in the soon-to-be-created x/exp/typeparams module.

I was wondering what's the current status of this, if it has evolved :) I tried using go/types/testdata/examples, but it contains some /* ERROR ... */ lines, presumably failing to typecheck on purpose - so it's no good as-is as a generic code corpus for tools. I also found https://github.com/golang/exp/tree/master/typeparams/example, though it seems to be a collection of example tools, so it's not quite what I'm after either.

mvdan commented 2 years ago

To give some more context: I'm after hundreds of lines of Go code, not thousands or tens of thousands, because that code will need to be copied to each of the modules for the tools which I need to ensure don't panic on e.g. unexpected go/ast nodes for generic code. I imagine that one wouldn't need that much code to represent most syntax and typechecking edge cases :)

gopherbot commented 2 years ago

Change https://go.dev/cl/402254 mentions this issue: go.mod: update to golang.org/x/text v0.1.10

findleyr commented 2 years ago

@mvdan

I was wondering what's the current status of this, if it has evolved :)

No status change as far as I know, sorry. I think we'd welcome an addition to x/exp/typeparams. Perhaps the corpus should be available as an importable package within that module? Would that work for your purposes, or would you more likely make a copy?

I tried using go/types/testdata/examples, but it contains some / ERROR ... / lines, presumably failing to typecheck on purpose

Yes, those comments denote expected errors.

  • so it's no good as-is as a generic code corpus for tools.

That depends on whether you want to test your tool in the presence of errors, I suppose, but your point stands. I think a good starting point for a corpus may be to filter out those error cases.

zchee commented 2 years ago

@findleyr very nits, but goa/goagen link url is now https://github.com/golang/go/issues/github.com/goadesign/goa/goagen.

findleyr commented 2 years ago

@findleyr very nits, but goa/goagen link url is now https://github.com/golang/go/issues/github.com/goadesign/goa/goagen.

Thanks. That URL doesn't look right (it starts with github.com/golang...), but I updated the goagen URL based on a Google search. Please let me know if it's still not right.

zchee commented 2 years ago

@findleyr Thanks for fix.

But, I'm not familiar with goa, but goa seems to already released v3 using v3 default branch. Also gen move to subcommand.

So, I think correct URL is just: https://github.com/goadesign/goa