cmd/godoc: bake templates and scripts into godoc binary

Add godoc/vfs/mapfs package for serving baked files.

Fixes golang/go#6010.

R=golang-dev, bradfitz, r, arnehormann, rsc
CC=golang-dev
https://golang.org/cl/12978043

cmd/godoc/bake.go

@@ -0,0 +1,64 @@
+// Copyright 2013 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.
+
+// +build ignore
+
+// Command bake takes a list of file names and writes a Go source file to
+// standard output that declares a map of string constants containing the input files.
+//
+// For example, the command
+// 	bake foo.html bar.txt
+// produces a source file in package main that declares the variable bakedFiles
+// that is a map with keys "foo.html" and "bar.txt" that contain the contents
+// of foo.html and bar.txt.
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"unicode/utf8"
+)
+
+func main() {
+	if err := bake(os.Args[1:]); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}
+
+func bake(files []string) error {
+	w := bufio.NewWriter(os.Stdout)
+	fmt.Fprintf(w, "%v\n\npackage main\n\n", warning)
+	fmt.Fprintf(w, "var bakedFiles = map[string]string{\n")
+	for _, fn := range files {
+		b, err := ioutil.ReadFile(fn)
+		if err != nil {
+			return err
+		}
+		if !utf8.Valid(b) {
+			return fmt.Errorf("file %s is not valid UTF-8", fn)
+		}
+		fmt.Fprintf(w, "\t%q: `%s`,\n", filepath.Base(fn), sanitize(b))
+	}
+	fmt.Fprintln(w, "}")
+	return w.Flush()
+}
+
+// sanitize prepares a string as a raw string constant.
+func sanitize(b []byte) []byte {
+	// Replace ` with `+"`"+`
+	b = bytes.Replace(b, []byte("`"), []byte("`+\"`\"+`"), -1)
+
+	// Replace BOM with `+"\xEF\xBB\xBF"+`
+	// (A BOM is valid UTF-8 but not permitted in Go source files.
+	// I wouldn't bother handling this, but for some insane reason
+	// jquery.js has a BOM somewhere in the middle.)
+	return bytes.Replace(b, []byte("\xEF\xBB\xBF"), []byte("`+\"\\xEF\\xBB\\xBF\"+`"), -1)
+}
+
+const warning = "// DO NOT EDIT ** This file was generated with the bake tool ** DO NOT EDIT //"

cmd/godoc/bake.sh

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+# Copyright 2013 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.
+
+set -e
+
+go run bake.go template/* | gofmt > template.go
+

cmd/godoc/main.go

@@ -50,6 +50,7 @@ import (
 
 	"code.google.com/p/go.tools/godoc"
 	"code.google.com/p/go.tools/godoc/vfs"
+	"code.google.com/p/go.tools/godoc/vfs/mapfs"
 	"code.google.com/p/go.tools/godoc/vfs/zipfs"
 )
 
@@ -196,13 +197,7 @@ func main() {
 		if *templateDir != "" {
 			fs.Bind("/lib/godoc", vfs.OS(*templateDir), "/", vfs.BindBefore)
 		} else {
-			// Read templates from go.tools repository; if not
+			fs.Bind("/lib/godoc", mapfs.New(bakedFiles), "/", vfs.BindReplace)
-			// found there, fall back on $GOROOT/lib/godoc
-			// which will be present in binary distributions.
-			pkg, err := build.Import(templatePath, "", build.FindOnly)
-			if err == nil {
-				fs.Bind("/lib/godoc", vfs.OS(pkg.Dir), "/", vfs.BindReplace)
-			}
 		}
 	} else {
 		// use file system specified via .zip file (path separator must be '/')

godoc/vfs/mapfs/mapfs.go

@@ -0,0 +1,81 @@
+// Copyright 2013 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.
+
+// Package mapfs file provides an implementation of the FileSystem
+// interface based on the contents of a map[string]string.
+package mapfs
+
+import (
+	"io"
+	"os"
+	"strings"
+	"time"
+
+	"code.google.com/p/go.tools/godoc/vfs"
+)
+
+func New(m map[string]string) vfs.FileSystem {
+	return mapFS(m)
+}
+
+// mapFS is the map based implementation of FileSystem
+type mapFS map[string]string
+
+func (fs mapFS) String() string { return "mapfs" }
+
+func (fs mapFS) Close() error { return nil }
+
+func filename(p string) string {
+	if len(p) > 0 && p[0] == '/' {
+		p = p[1:]
+	}
+	return p
+}
+
+func (fs mapFS) Open(p string) (vfs.ReadSeekCloser, error) {
+	b, ok := fs[filename(p)]
+	if !ok {
+		return nil, os.ErrNotExist
+	}
+	return nopCloser{strings.NewReader(b)}, nil
+}
+
+func (fs mapFS) Lstat(p string) (os.FileInfo, error) {
+	b, ok := fs[filename(p)]
+	if !ok {
+		return nil, os.ErrNotExist
+	}
+	return mapFI{name: p, size: int64(len(b))}, nil
+}
+
+func (fs mapFS) Stat(p string) (os.FileInfo, error) {
+	return fs.Lstat(p)
+}
+
+func (fs mapFS) ReadDir(p string) ([]os.FileInfo, error) {
+	var list []os.FileInfo
+	for fn, b := range fs {
+		list = append(list, mapFI{name: fn, size: int64(len(b))})
+	}
+	return list, nil
+}
+
+// mapFI is the map-based implementation of FileInfo.
+type mapFI struct {
+	name string
+	size int64
+}
+
+func (fi mapFI) IsDir() bool        { return false }
+func (fi mapFI) ModTime() time.Time { return time.Time{} }
+func (fi mapFI) Mode() os.FileMode  { return 0444 }
+func (fi mapFI) Name() string       { return fi.name }
+func (fi mapFI) Size() int64        { return fi.size }
+func (fi mapFI) Sys() interface{}   { return nil }
+
+type nopCloser struct {
+	io.ReadSeeker
+}
+
+func (nc nopCloser) Close() error { return nil }