all: rework goimports environment, support GOMODCACHE

This CL got away from me a little.

For a number of reasons, the existing goimports API of passing in values
for various GO* values was not working. For one, the number of necessary
variables kept growing. For another, we tried to avoid calling `go env`
in GOPATH mode by using `build.Default`, but that turns out to be buggy;
see golang/go#39838. And finally, it created massive confusion about
whether the values were intended to be read from the OS environment, or
fully evaluated by the `go` command.

There are only two users of the internal imports API, so there really
shouldn't need to be more than two modes. For the command line tool, we
have to call `go env` to deal with the `go/build` bug. So we just do it.
Tests use that same path, but can augment the enviroment to set
themselves up. In contrast, `gopls` needs to fully specify the
environment. It can simply pass in the fully evaluated GO* values.

Finally, make the change I was actually here to make: propagate
GOMODCACHE and use it where appropriate.

Fixes golang/go#39761.

Change-Id: I720c69839d91d66d98e94dfc5f065ba0279c5542
Reviewed-on: https://go-review.googlesource.com/c/tools/+/239754
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
13 files changed
tree: e0f0948e0f0bd54a548949d01191fe98c46034f5
  1. benchmark/
  2. blog/
  3. cmd/
  4. container/
  5. cover/
  6. go/
  7. godoc/
  8. gopls/
  9. imports/
  10. internal/
  11. playground/
  12. present/
  13. refactor/
  14. txtar/
  15. .gitattributes
  16. .gitignore
  17. .prettierrc
  18. AUTHORS
  19. codereview.cfg
  20. CONTRIBUTING.md
  21. CONTRIBUTORS
  22. go.mod
  23. go.sum
  24. LICENSE
  25. PATENTS
  26. README.md
README.md

Go Tools

This subrepository holds the source for various packages and tools that support the Go programming language.

Some of the tools, godoc and vet for example, are included in binary Go distributions.

Others, including the Go guru and the test coverage tool, can be fetched with go get.

Packages include a type-checker for Go and an implementation of the Static Single Assignment form (SSA) representation for Go programs.

Download/Install

The easiest way to install is to run go get -u golang.org/x/tools/.... You can also manually git clone the repository to $GOPATH/src/golang.org/x/tools.

JS/CSS Formatting

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The version of prettier used is 1.18.2.

It is encouraged that all JS and CSS code be run through this before submitting a change. However, it is not a strict requirement enforced by CI.

Report Issues / Send Patches

This repository uses Gerrit for code changes. To learn how to submit changes to this repository, see https://golang.org/doc/contribute.html.

The main issue tracker for the tools repository is located at https://github.com/golang/go/issues. Prefix your issue with “x/tools/(your subdir):” in the subject line, so it is easy to find.