Update golang.org/x/tools release and third-party "extra" patch

[bartle-stripe]

What version of rules_go are you using?

5ecc2d3

What version of gazelle are you using?

0.21.0

What version of Bazel are you using?

3.0.0

Does this issue reproduce with the latest releases of all the above?

Yes

What operating system and processor architecture are you using?

macOS Catalina

What did you do?

Vendor golang.org/x/tools at/past golang/tools@5c6ccfd

What did you expect to see?

bazel build @org_golang_x_tools//... works.

What did you see instead?

/org_golang_x_tools/go/internal/gcimporter/gcimporter.go:213:18: undefined: BImportData
/org_golang_x_tools/go/internal/gcimporter/iexport.go:36:22: undefined: internalError
/org_golang_x_tools/go/internal/gcimporter/iexport.go:55:21: undefined: predeclared
/org_golang_x_tools/go/internal/gcimporter/iexport.go:59:9: undefined: internalErrorf
/org_golang_x_tools/go/internal/gcimporter/iexport.go:222:10: undefined: internalErrorf
/org_golang_x_tools/go/internal/gcimporter/iexport.go:255:10: undefined: internalErrorf
/org_golang_x_tools/go/internal/gcimporter/iexport.go:270:9: undefined: internalErrorf
/org_golang_x_tools/go/internal/gcimporter/iexport.go:302:15: undefined: deltaNewFile
/org_golang_x_tools/go/internal/gcimporter/iexport.go:306:11: undefined: deltaNewFile
/org_golang_x_tools/go/internal/gcimporter/iimport.go:189:16: undefined: fakeFileSet
/org_golang_x_tools/go/internal/gcimporter/iexport.go:306:11: too many errors

The commit above refactored things by adding a couple new files (bimport.go and bexport.go), which isn't reflected in https://github.com/bazelbuild/rules_go/blob/master/third_party/org_golang_x_tools-extras.patch.

It'd be great to also include a README file in https://github.com/bazelbuild/rules_go/tree/master/third_party that explains how one might generate these patches (in particular, the "extra" patches), or a BUILD rules that can generate them automatically.

[bartle-stripe]

I wonder if the extra patch could be made more robust by changing srcs to something like srcs = glob(["*.go"], exclude = ["*_test.go"]).

[jayconrod]

I'm confused about what's happening here exactly. You mentioned you're vendoring golang.org/x/tools. How are you using the vendored copy together with org_golang_x_tools? They will conflict.

Overriding dependencies is the documentation for using alternate versions of repositories declared in go_rules_dependencies. It's a good idea to point to that document from //third_party. I'll add a README file there.

About the extras patches: I don't want spend too much time automating generation of these: I'd rather avoid the need for them by fixing #2374. Unfortunately, that's still blocked on bazelbuild/bazel#11291.

[jayconrod]

I'll update org_golang_x_tools together with the others in preparation for the v0.24.0 release next month. I won't update dependencies outside of that cycle, since it's a fair amount of work to get everything to work together, and it doesn't benefit many people until it's released.

[bartle-stripe]

We have a setup where we basically drop a WORKSPACE file in e.g. vendor/golang.org/x/tools, named org_golang_x_tools, before we call go_rules_dependencies(). But, I'd expect following the approach you linked would result in the same problem?

[jayconrod]

Seems like that should work. The patches will need to be applied manually, and they'll need to be updated for the version you're using, but I can't think of any other issues.

[bartle-stripe]

Yup, for now I'm actually just applying a slightly altered version of the patch:

--- tools/build/org_golang_x_tools-extras.patch	2020-07-08 12:16:12.000000000 -0700
+++ src/rules_go/third_party/org_golang_x_tools-extras.patch	2020-05-13 23:17:26.000000000 -0700
@@ -1185,15 +1185,13 @@

  go_library(
      name = "go_default_library",
-@@ -14,6 +14,22 @@
+@@ -14,6 +14,20 @@
      visibility = ["//go:__subpackages__"],
  )

 +go_tool_library(
 +    name = "go_tool_library",
 +    srcs = [
-+        "bexport.go",
-+        "bimport.go",
 +        "exportdata.go",
 +        "gcimporter.go",
 +        "iexport.go",