From fe1a27b55bb12199b0a4f5d12f757763a8ded30e Mon Sep 17 00:00:00 2001
From: Robert Findley <rfindley@google.com>
Date: Tue, 30 Aug 2022 16:26:24 -0400
Subject: [PATCH] gopls/doc: make doc generation work regardless of the current
 directory

As a nice side effect, make it easier to migrate internal/lsp/ to
gopls/internal/lsp.

For golang/go#54509

Change-Id: Ib541c08426f1f1d1e2a42b2d1cab47eab96dc092
Reviewed-on: https://go-review.googlesource.com/c/tools/+/426775
Reviewed-by: Alan Donovan <adonovan@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
gopls-CI: kokoro <noreply+kokoro@google.com>
---
 gopls/doc/generate.go      | 35 ++++++++++++++++++++++++++++-------
 gopls/doc/generate_test.go |  2 +-
 2 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/gopls/doc/generate.go b/gopls/doc/generate.go
index c7e0e0ffcc0..28e0444a467 100644
--- a/gopls/doc/generate.go
+++ b/gopls/doc/generate.go
@@ -20,6 +20,7 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"reflect"
 	"regexp"
@@ -39,37 +40,57 @@ import (
 )
 
 func main() {
-	if _, err := doMain("..", true); err != nil {
+	if _, err := doMain(true); err != nil {
 		fmt.Fprintf(os.Stderr, "Generation failed: %v\n", err)
 		os.Exit(1)
 	}
 }
 
-func doMain(baseDir string, write bool) (bool, error) {
+func doMain(write bool) (bool, error) {
 	api, err := loadAPI()
 	if err != nil {
 		return false, err
 	}
 
-	if ok, err := rewriteFile(filepath.Join(baseDir, "internal/lsp/source/api_json.go"), api, write, rewriteAPI); !ok || err != nil {
+	sourceDir, err := pkgDir("golang.org/x/tools/internal/lsp/source")
+	if err != nil {
+		return false, err
+	}
+
+	if ok, err := rewriteFile(filepath.Join(sourceDir, "api_json.go"), api, write, rewriteAPI); !ok || err != nil {
 		return ok, err
 	}
-	if ok, err := rewriteFile(filepath.Join(baseDir, "gopls/doc/settings.md"), api, write, rewriteSettings); !ok || err != nil {
+
+	goplsDir, err := pkgDir("golang.org/x/tools/gopls")
+	if err != nil {
+		return false, err
+	}
+
+	if ok, err := rewriteFile(filepath.Join(goplsDir, "doc", "settings.md"), api, write, rewriteSettings); !ok || err != nil {
 		return ok, err
 	}
-	if ok, err := rewriteFile(filepath.Join(baseDir, "gopls/doc/commands.md"), api, write, rewriteCommands); !ok || err != nil {
+	if ok, err := rewriteFile(filepath.Join(goplsDir, "doc", "commands.md"), api, write, rewriteCommands); !ok || err != nil {
 		return ok, err
 	}
-	if ok, err := rewriteFile(filepath.Join(baseDir, "gopls/doc/analyzers.md"), api, write, rewriteAnalyzers); !ok || err != nil {
+	if ok, err := rewriteFile(filepath.Join(goplsDir, "doc", "analyzers.md"), api, write, rewriteAnalyzers); !ok || err != nil {
 		return ok, err
 	}
-	if ok, err := rewriteFile(filepath.Join(baseDir, "gopls/doc/inlayHints.md"), api, write, rewriteInlayHints); !ok || err != nil {
+	if ok, err := rewriteFile(filepath.Join(goplsDir, "doc", "inlayHints.md"), api, write, rewriteInlayHints); !ok || err != nil {
 		return ok, err
 	}
 
 	return true, nil
 }
 
+// pkgDir returns the directory corresponding to the import path pkgPath.
+func pkgDir(pkgPath string) (string, error) {
+	out, err := exec.Command("go", "list", "-f", "{{.Dir}}", pkgPath).Output()
+	if err != nil {
+		return "", err
+	}
+	return strings.TrimSpace(string(out)), nil
+}
+
 func loadAPI() (*source.APIJSON, error) {
 	pkgs, err := packages.Load(
 		&packages.Config{
diff --git a/gopls/doc/generate_test.go b/gopls/doc/generate_test.go
index 137a646cd8d..d33594d6159 100644
--- a/gopls/doc/generate_test.go
+++ b/gopls/doc/generate_test.go
@@ -16,7 +16,7 @@ import (
 func TestGenerated(t *testing.T) {
 	testenv.NeedsGoBuild(t) // This is a lie. We actually need the source code.
 
-	ok, err := doMain("../..", false)
+	ok, err := doMain(false)
 	if err != nil {
 		t.Fatal(err)
 	}