internal/lsp: improve errors in multi-module workspaces (GO111MODULE=on)

Currently, when a user opens a workspace with no top-level module but
multiple modules in subdirectories, gopls treats that as an invalid
build configuration and reports an error message that may be difficult
for the user to understand (a go list error message about creating a
main module in the top-level directory). Instead, show a more useful
error message about the gopls workspace layout in both the progress bar
and as a diagnostic on every open file.

This fix only works for GO111MODULE=on (for now) because it's a lot
easier to interpret user intent, and the go command will return no
packages. The next step will be to improve error messaging for
GO111MODULE=auto and for users with nested modules.

Updates golang/go#42109

Change-Id: I702ca6745f7e080ff6704ade7843972ab469ccf3
Reviewed-on: https://go-review.googlesource.com/c/tools/+/272346
Trust: Rebecca Stambler <rstambler@golang.org>
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
6 files changed
tree: 71007e918b999a14e00af3b74bfd4968fb3f5bad
  1. .gitattributes
  2. .gitignore
  3. .prettierrc
  4. AUTHORS
  5. CONTRIBUTING.md
  6. CONTRIBUTORS
  7. LICENSE
  8. PATENTS
  9. README.md
  10. benchmark/
  11. blog/
  12. cmd/
  13. codereview.cfg
  14. container/
  15. cover/
  16. go.mod
  17. go.sum
  18. go/
  19. godoc/
  20. gopls/
  21. imports/
  22. internal/
  23. playground/
  24. present/
  25. refactor/
  26. txtar/
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

This repository uses prettier to format JS and CSS files.

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.