blob: 634e28756251fc8a33b6ce799793527d1f27040f [file] [log] [blame]
package source
import (
const (
// TODO(rstambler): We should really be able to point to a link on the website.
modulesWiki = ""
func checkCommonErrors(ctx context.Context, view View, uri span.URI) (string, error) {
// Unfortunately, we probably can't have go/packages expose a function like this.
// Since we only really understand the `go` command, check the user's GOPACKAGESDRIVER
// and, if they are using `go list`, consider the possible error cases.
gopackagesdriver := os.Getenv("GOPACKAGESDRIVER")
if gopackagesdriver != "" && gopackagesdriver != "off" {
return "", nil
// Some cases we should be able to detect:
// 1. The user is in GOPATH mode and is working outside their GOPATH
// 2. The user is in module mode and has opened a subdirectory of their module
gopath := os.Getenv("GOPATH")
cfg := view.Config(ctx)
// Invoke `go env GOMOD` inside of the directory of the file.
fdir := filepath.Dir(uri.Filename())
b, err := invokeGo(ctx, fdir, cfg.Env, "env", "GOMOD")
if err != nil {
return "", err
modFile := strings.TrimSpace(b.String())
if modFile == filepath.FromSlash("/dev/null") {
modFile = ""
// Not inside of a module.
inAModule := modFile != ""
inGopath := strings.HasPrefix(uri.Filename(), filepath.Join(gopath, "src"))
moduleMode := os.Getenv("GO111MODULE")
var msg string
// The user is in a module.
if inAModule {
// The workspace root is open to a directory different from the module root.
if modRoot := filepath.Dir(modFile); cfg.Dir != filepath.Dir(modFile) {
msg = fmt.Sprintf("Your workspace root is %s, but your module root is %s. Please add %s as a workspace folder.", cfg.Dir, modRoot, modRoot)
} else if inGopath {
if moduleMode == "on" {
msg = "You are in module mode, but you are not inside of a module. Please create a module."
} else {
msg = fmt.Sprintf("You are neither in a module nor in your GOPATH. Please see %s for information on how to set up your Go project.", modulesWiki)
return msg, nil
// invokeGo returns the stdout of a go command invocation.
// Borrowed from
func invokeGo(ctx context.Context, dir string, env []string, args ...string) (*bytes.Buffer, error) {
stdout := new(bytes.Buffer)
stderr := new(bytes.Buffer)
cmd := exec.CommandContext(ctx, "go", args...)
// On darwin the cwd gets resolved to the real path, which breaks anything that
// expects the working directory to keep the original path, including the
// go command when dealing with modules.
// The Go stdlib has a special feature where if the cwd and the PWD are the
// same node then it trusts the PWD, so by setting it in the env for the child
// process we fix up all the paths returned by the go command.
cmd.Env = append(append([]string{}, env...), "PWD="+dir)
cmd.Dir = dir
cmd.Stdout = stdout
cmd.Stderr = stderr
if err := cmd.Run(); err != nil {
// Check for 'go' executable not being found.
if ee, ok := err.(*exec.Error); ok && ee.Err == exec.ErrNotFound {
return nil, fmt.Errorf("'gopls requires 'go', but %s", exec.ErrNotFound)
if _, ok := err.(*exec.ExitError); !ok {
// Catastrophic error:
// - context cancellation
return nil, fmt.Errorf("couldn't exec 'go %v': %s %T", args, err, err)
return stdout, nil