internal/lsp: print the go version only once the view is created

Printing the Go version without the session's go command runner means
that we may not find the right Go version. Also, panicking when we
cannot find a go command is not useful to the user--show the error as a
view initialization error instead.

Fixes golang/go#41701

Change-Id: I0e0753da9795b1c78331db1faecd27c2bfcee9b4
Reviewed-on: https://go-review.googlesource.com/c/tools/+/258312
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>

internal/lsp/cache/view.go

@@ -358,8 +358,26 @@ func (s *snapshot) WriteEnv(ctx context.Context, w io.Writer) error {
 			fullEnv[s[0]] = s[1]
 		}
 	}
-	fmt.Fprintf(w, "go env for %v\n(root %s)\n(valid build configuration = %v)\n(build flags: %v)\n",
-		s.view.folder.Filename(), s.view.rootURI.Filename(), s.view.hasValidBuildConfiguration, buildFlags)
+	goVersion, err := s.view.session.gocmdRunner.Run(ctx, gocommand.Invocation{
+		Verb:       "version",
+		BuildFlags: buildFlags,
+		Env:        env,
+		WorkingDir: s.view.rootURI.Filename(),
+	})
+	if err != nil {
+		return err
+	}
+	fmt.Fprintf(w, `go env for %v
+(root %s)
+(go version %s)
+(valid build configuration = %v)
+(build flags: %v)
+`,
+		s.view.folder.Filename(),
+		s.view.rootURI.Filename(),
+		goVersion.String(),
+		s.view.hasValidBuildConfiguration,
+		buildFlags)
 	for k, v := range fullEnv {
 		fmt.Fprintf(w, "%s=%s\n", k, v)
 	}

internal/lsp/debug/info.go

@@ -10,8 +10,6 @@ import (
 	"fmt"
 	"io"
 	"strings"
-
-	"golang.org/x/tools/internal/gocommand"
 )
 
 type PrintMode int
@@ -48,17 +46,6 @@ func PrintVersionInfo(ctx context.Context, w io.Writer, verbose bool, mode Print
 	section(w, mode, "Build info", func() {
 		printBuildInfo(w, true, mode)
 	})
-	fmt.Fprint(w, "\n")
-	section(w, mode, "Go info", func() {
-		gocmdRunner := &gocommand.Runner{}
-		version, err := gocmdRunner.Run(ctx, gocommand.Invocation{
-			Verb: "version",
-		})
-		if err != nil {
-			panic(err)
-		}
-		fmt.Fprintln(w, version.String())
-	})
 }
 
 func section(w io.Writer, mode PrintMode, title string, body func()) {

internal/lsp/general.go

@@ -18,7 +18,6 @@ import (
 	"golang.org/x/tools/internal/event"
 	"golang.org/x/tools/internal/jsonrpc2"
 	"golang.org/x/tools/internal/lsp/debug"
-	"golang.org/x/tools/internal/lsp/debug/tag"
 	"golang.org/x/tools/internal/lsp/protocol"
 	"golang.org/x/tools/internal/lsp/source"
 	"golang.org/x/tools/internal/span"
@@ -165,12 +164,6 @@ func (s *Server) initialized(ctx context.Context, params *protocol.InitializedPa
 	options := s.session.Options()
 	defer func() { s.session.SetOptions(options) }()
 
-	// TODO: this event logging may be unnecessary.
-	// The version info is included in the initialize response.
-	buf := &bytes.Buffer{}
-	debug.PrintVersionInfo(ctx, buf, true, debug.PlainText)
-	event.Log(ctx, buf.String())
-
 	if err := s.addFolders(ctx, s.pendingFolders); err != nil {
 		return err
 	}
@@ -217,7 +210,7 @@ func (s *Server) addFolders(ctx context.Context, folders []protocol.WorkspaceFol
 			continue
 		}
 		work := s.progress.start(ctx, "Setting up workspace", "Loading packages...", nil, nil)
-		view, snapshot, release, err := s.addView(ctx, folder.Name, uri)
+		snapshot, release, err := s.addView(ctx, folder.Name, uri)
 		if err != nil {
 			viewErrors[uri] = err
 			work.end(fmt.Sprintf("Error loading packages: %s", err))
@@ -238,7 +231,7 @@ func (s *Server) addFolders(ctx context.Context, folders []protocol.WorkspaceFol
 		// Print each view's environment.
 		buf := &bytes.Buffer{}
 		if err := snapshot.WriteEnv(ctx, buf); err != nil {
-			event.Error(ctx, "failed to write environment", err, tag.Directory.Of(view.Folder().Filename()))
+			viewErrors[uri] = err
 			continue
 		}
 		event.Log(ctx, buf.String())

internal/lsp/workspace.go

@@ -26,18 +26,19 @@ func (s *Server) didChangeWorkspaceFolders(ctx context.Context, params *protocol
 	return s.addFolders(ctx, event.Added)
 }
 
-func (s *Server) addView(ctx context.Context, name string, uri span.URI) (source.View, source.Snapshot, func(), error) {
+func (s *Server) addView(ctx context.Context, name string, uri span.URI) (source.Snapshot, func(), error) {
 	s.stateMu.Lock()
 	state := s.state
 	s.stateMu.Unlock()
 	if state < serverInitialized {
-		return nil, nil, func() {}, errors.Errorf("addView called before server initialized")
+		return nil, func() {}, errors.Errorf("addView called before server initialized")
 	}
 	options := s.session.Options().Clone()
 	if err := s.fetchConfig(ctx, name, uri, options); err != nil {
-		return nil, nil, func() {}, err
+		return nil, func() {}, err
 	}
-	return s.session.NewView(ctx, name, uri, options)
+	_, snapshot, release, err := s.session.NewView(ctx, name, uri, options)
+	return snapshot, release, err
 }
 
 func (s *Server) didChangeConfiguration(ctx context.Context, changed interface{}) error {