internal/lsp: print view-specific environment

For debugging purposes, we print the output of `go env` on start. Now,
we print a view-specific `go env`, which will helps us when debugging
multi-project workspaces. Additional information included: the folder of
the view, if the view has a valid build configuration, and the build
flags for the view.

Updates golang/go#37978

Change-Id: Iadffd46f8ac5410971558a304b8bbcb2f9bdbcc3
Reviewed-on: https://go-review.googlesource.com/c/tools/+/225137
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>

internal/lsp/cache/load.go

@@ -93,7 +93,7 @@ func (s *snapshot) load(ctx context.Context, scopes ...interface{}) error {
 		return ctx.Err()
 	}
 
-	event.Print(ctx, "go/packages.Load", tag.Snapshot.Of(s.ID()), tag.Query.Of(query), tag.PackageCount.Of(len(pkgs)))
+	event.Print(ctx, "go/packages.Load", tag.Snapshot.Of(s.ID()), tag.Directory.Of(cfg.Dir), tag.Query.Of(query), tag.PackageCount.Of(len(pkgs)))
 	if len(pkgs) == 0 {
 		return err
 	}

internal/lsp/cache/view.go

@@ -262,6 +262,24 @@ func (v *view) buildBuiltinPackage(ctx context.Context, goFiles []string) error
 	return nil
 }
 
+func (v *view) WriteEnv(ctx context.Context, w io.Writer) error {
+	env, buildFlags := v.env()
+	// TODO(rstambler): We could probably avoid running this by saving the
+	// output on original create, but I'm not sure if it's worth it.
+	inv := gocommand.Invocation{
+		Verb:       "env",
+		Env:        env,
+		WorkingDir: v.Folder().Filename(),
+	}
+	stdout, err := inv.Run(ctx)
+	if err != nil {
+		return err
+	}
+	fmt.Fprintf(w, "go env for %v\n(valid build configuration = %v)\n(build flags: %v)\n", v.folder.Filename(), v.hasValidBuildConfiguration, buildFlags)
+	fmt.Fprint(w, stdout)
+	return nil
+}
+
 func (v *view) RunProcessEnvFunc(ctx context.Context, fn func(*imports.Options) error) error {
 	v.importsMu.Lock()
 	defer v.importsMu.Unlock()

internal/lsp/cmd/info.go

@@ -32,7 +32,7 @@ func (v *version) DetailedHelp(f *flag.FlagSet) {
 
 // Run prints version information to stdout.
 func (v *version) Run(ctx context.Context, args ...string) error {
-	debug.PrintVersionInfo(os.Stdout, v.app.Verbose, debug.PlainText)
+	debug.PrintVersionInfo(ctx, os.Stdout, v.app.Verbose, debug.PlainText)
 	return nil
 }
 
@@ -69,7 +69,7 @@ A failing unit test is the best.
 func (b *bug) Run(ctx context.Context, args ...string) error {
 	buf := &bytes.Buffer{}
 	fmt.Fprint(buf, goplsBugHeader)
-	debug.PrintVersionInfo(buf, true, debug.Markdown)
+	debug.PrintVersionInfo(ctx, buf, true, debug.Markdown)
 	body := buf.String()
 	title := strings.Join(args, " ")
 	if !strings.HasPrefix(title, goplsBugPrefix) {

internal/lsp/debug/info.go

@@ -6,10 +6,12 @@
 package debug
 
 import (
+	"context"
 	"fmt"
 	"io"
-	"os/exec"
 	"strings"
+
+	"golang.org/x/tools/internal/gocommand"
 )
 
 type PrintMode int
@@ -24,7 +26,7 @@ const (
 var Version = "master"
 
 // PrintServerInfo writes HTML debug info to w for the Instance.
-func (i *Instance) PrintServerInfo(w io.Writer) {
+func (i *Instance) PrintServerInfo(ctx context.Context, w io.Writer) {
 	section(w, HTML, "Server Instance", func() {
 		fmt.Fprintf(w, "Start time: %v\n", i.StartTime)
 		fmt.Fprintf(w, "LogFile: %s\n", i.Logfile)
@@ -32,13 +34,13 @@ func (i *Instance) PrintServerInfo(w io.Writer) {
 		fmt.Fprintf(w, "Address: %s\n", i.ServerAddress)
 		fmt.Fprintf(w, "Debug address: %s\n", i.DebugAddress)
 	})
-	PrintVersionInfo(w, true, HTML)
+	PrintVersionInfo(ctx, w, true, HTML)
 }
 
-// PrintVersionInfo writes version and environment information to w, using the
-// output format specified by mode. verbose controls whether additional
-// information is written, including section headers.
-func PrintVersionInfo(w io.Writer, verbose bool, mode PrintMode) {
+// PrintVersionInfo writes version information to w, using the output format
+// specified by mode. verbose controls whether additional information is
+// written, including section headers.
+func PrintVersionInfo(ctx context.Context, w io.Writer, verbose bool, mode PrintMode) {
 	if !verbose {
 		printBuildInfo(w, false, mode)
 		return
@@ -48,13 +50,14 @@ func PrintVersionInfo(w io.Writer, verbose bool, mode PrintMode) {
 	})
 	fmt.Fprint(w, "\n")
 	section(w, mode, "Go info", func() {
-		cmd := exec.Command("go", "version")
-		cmd.Stdout = w
-		cmd.Run()
-		fmt.Fprint(w, "\n")
-		cmd = exec.Command("go", "env")
-		cmd.Stdout = w
-		cmd.Run()
+		i := &gocommand.Invocation{
+			Verb: "version",
+		}
+		version, err := i.Run(ctx)
+		if err != nil {
+			panic(err)
+		}
+		fmt.Fprintln(w, version.String())
 	})
 }
 

internal/lsp/debug/serve.go

@@ -376,7 +376,7 @@ func (i *Instance) getFile(r *http.Request) interface{} {
 
 func (i *Instance) getInfo(r *http.Request) interface{} {
 	buf := &bytes.Buffer{}
-	i.PrintServerInfo(buf)
+	i.PrintServerInfo(r.Context(), buf)
 	return template.HTML(buf.String())
 }
 

internal/lsp/general.go

@@ -13,6 +13,7 @@ import (
 
 	"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"
@@ -156,7 +157,7 @@ func (s *Server) initialized(ctx context.Context, params *protocol.InitializedPa
 	}
 
 	buf := &bytes.Buffer{}
-	debug.PrintVersionInfo(buf, true, debug.PlainText)
+	debug.PrintVersionInfo(ctx, buf, true, debug.PlainText)
 	event.Print(ctx, buf.String())
 
 	s.addFolders(ctx, s.pendingFolders)
@@ -171,11 +172,20 @@ func (s *Server) addFolders(ctx context.Context, folders []protocol.WorkspaceFol
 
 	for _, folder := range folders {
 		uri := span.URIFromURI(folder.URI)
-		_, snapshot, err := s.addView(ctx, folder.Name, uri)
+		view, snapshot, err := s.addView(ctx, folder.Name, uri)
 		if err != nil {
 			viewErrors[uri] = err
 			continue
 		}
+		// Print each view's environment.
+		buf := &bytes.Buffer{}
+		if err := view.WriteEnv(ctx, buf); err != nil {
+			event.Error(ctx, "failed to write environment", err, tag.Directory.Of(view.Folder()))
+			continue
+		}
+		event.Print(ctx, buf.String())
+
+		// Diagnose the newly created view.
 		go s.diagnoseDetached(snapshot)
 	}
 	if len(viewErrors) > 0 {

internal/lsp/source/view.go

@@ -10,6 +10,7 @@ import (
 	"go/ast"
 	"go/token"
 	"go/types"
+	"io"
 
 	"golang.org/x/mod/modfile"
 	"golang.org/x/tools/go/analysis"
@@ -125,6 +126,9 @@ type View interface {
 	// Ignore returns true if this file should be ignored by this view.
 	Ignore(span.URI) bool
 
+	// WriteEnv writes the view-specific environment to the io.Writer.
+	WriteEnv(ctx context.Context, w io.Writer) error
+
 	// RunProcessEnvFunc runs fn with the process env for this snapshot's view.
 	// Note: the process env contains cached module and filesystem state.
 	RunProcessEnvFunc(ctx context.Context, fn func(*imports.Options) error) error