--- /dev/null
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Command generate updates settings.md from the UserOptions struct.
+package main
+
+import (
+ "bytes"
+ "encoding/json"
+ "fmt"
+ "io/ioutil"
+ "os"
+ "path/filepath"
+ "regexp"
+ "strings"
+
+ "golang.org/x/tools/internal/lsp/source"
+)
+
+func main() {
+ 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) {
+ api := &source.APIJSON{}
+ if err := json.Unmarshal([]byte(source.GeneratedAPIJSON), api); err != nil {
+ return false, err
+ }
+
+ if ok, err := rewriteFile(filepath.Join(baseDir, "gopls/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 {
+ return ok, err
+ }
+
+ return true, nil
+}
+
+func rewriteFile(file string, api *source.APIJSON, write bool, rewrite func([]byte, *source.APIJSON) ([]byte, error)) (bool, error) {
+ doc, err := ioutil.ReadFile(file)
+ if err != nil {
+ return false, err
+ }
+
+ content, err := rewrite(doc, api)
+ if err != nil {
+ return false, fmt.Errorf("rewriting %q: %v", file, err)
+ }
+
+ if !bytes.Equal(doc, content) && !write {
+ return false, nil
+ }
+
+ if err := ioutil.WriteFile(file, content, 0); err != nil {
+ return false, err
+ }
+
+ return true, nil
+}
+
+var parBreakRE = regexp.MustCompile("\n{2,}")
+
+func rewriteSettings(doc []byte, api *source.APIJSON) ([]byte, error) {
+ result := doc
+ for category, opts := range api.Options {
+ section := bytes.NewBuffer(nil)
+ for _, opt := range opts {
+ var enumValues strings.Builder
+ if len(opt.EnumValues) > 0 {
+ enumValues.WriteString("Must be one of:\n\n")
+ for _, val := range opt.EnumValues {
+ if val.Doc != "" {
+ // Don't break the list item by starting a new paragraph.
+ unbroken := parBreakRE.ReplaceAllString(val.Doc, "\\\n")
+ fmt.Fprintf(&enumValues, " * %s\n", unbroken)
+ } else {
+ fmt.Fprintf(&enumValues, " * `%s`\n", val.Value)
+ }
+ }
+ }
+ fmt.Fprintf(section, "### **%v** *%v*\n%v%v\n\nDefault: `%v`.\n", opt.Name, opt.Type, opt.Doc, enumValues.String(), opt.Default)
+ }
+ var err error
+ result, err = replaceSection(result, category, section.Bytes())
+ if err != nil {
+ return nil, err
+ }
+ }
+
+ section := bytes.NewBuffer(nil)
+ for _, lens := range api.Lenses {
+ fmt.Fprintf(section, "### **%v**\nIdentifier: `%v`\n\n%v\n\n", lens.Title, lens.Lens, lens.Doc)
+ }
+ return replaceSection(result, "Lenses", section.Bytes())
+}
+
+func rewriteCommands(doc []byte, api *source.APIJSON) ([]byte, error) {
+ section := bytes.NewBuffer(nil)
+ for _, command := range api.Commands {
+ fmt.Fprintf(section, "### **%v**\nIdentifier: `%v`\n\n%v\n\n", command.Title, command.Command, command.Doc)
+ }
+ return replaceSection(doc, "Commands", section.Bytes())
+}
+
+func replaceSection(doc []byte, sectionName string, replacement []byte) ([]byte, error) {
+ re := regexp.MustCompile(fmt.Sprintf(`(?s)<!-- BEGIN %v.* -->\n(.*?)<!-- END %v.* -->`, sectionName, sectionName))
+ idx := re.FindSubmatchIndex(doc)
+ if idx == nil {
+ return nil, fmt.Errorf("could not find section %q", sectionName)
+ }
+ result := append([]byte(nil), doc[:idx[2]]...)
+ result = append(result, replacement...)
+ result = append(result, doc[idx[3]:]...)
+ return result, nil
+}