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>

2 files changed, 18 insertions, 15 deletions

diff --git a/internal/lsp/debug/info.go b/internal/lsp/debug/info.go
index 5890396c9..8baf1d932 100644
--- a/internal/lsp/debug/info.go
+++ b/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())
 	})
 }
 
diff --git a/internal/lsp/debug/serve.go b/internal/lsp/debug/serve.go
index ab08e1479..783574046 100644
--- a/internal/lsp/debug/serve.go
+++ b/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())
 }