Matthias Andreas Benkard | 832a54e | 2019-01-29 09:27:38 +0100 | [diff] [blame] | 1 | // +build ignore |
| 2 | |
| 3 | // Copyright 2013 The Go Authors. All rights reserved. |
| 4 | // Use of this source code is governed by a BSD-style |
| 5 | // license that can be found in the LICENSE file. |
| 6 | |
| 7 | // Command mkindex creates the file "pkgindex.go" containing an index of the Go |
| 8 | // standard library. The file is intended to be built as part of the imports |
| 9 | // package, so that the package may be used in environments where a GOROOT is |
| 10 | // not available (such as App Engine). |
| 11 | package main |
| 12 | |
| 13 | import ( |
| 14 | "bytes" |
| 15 | "fmt" |
| 16 | "go/ast" |
| 17 | "go/build" |
| 18 | "go/format" |
| 19 | "go/parser" |
| 20 | "go/token" |
| 21 | "io/ioutil" |
| 22 | "log" |
| 23 | "os" |
| 24 | "path" |
| 25 | "path/filepath" |
| 26 | "strings" |
| 27 | ) |
| 28 | |
| 29 | var ( |
| 30 | pkgIndex = make(map[string][]pkg) |
| 31 | exports = make(map[string]map[string]bool) |
| 32 | ) |
| 33 | |
| 34 | func main() { |
| 35 | // Don't use GOPATH. |
| 36 | ctx := build.Default |
| 37 | ctx.GOPATH = "" |
| 38 | |
| 39 | // Populate pkgIndex global from GOROOT. |
| 40 | for _, path := range ctx.SrcDirs() { |
| 41 | f, err := os.Open(path) |
| 42 | if err != nil { |
| 43 | log.Print(err) |
| 44 | continue |
| 45 | } |
| 46 | children, err := f.Readdir(-1) |
| 47 | f.Close() |
| 48 | if err != nil { |
| 49 | log.Print(err) |
| 50 | continue |
| 51 | } |
| 52 | for _, child := range children { |
| 53 | if child.IsDir() { |
| 54 | loadPkg(path, child.Name()) |
| 55 | } |
| 56 | } |
| 57 | } |
| 58 | // Populate exports global. |
| 59 | for _, ps := range pkgIndex { |
| 60 | for _, p := range ps { |
| 61 | e := loadExports(p.dir) |
| 62 | if e != nil { |
| 63 | exports[p.dir] = e |
| 64 | } |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | // Construct source file. |
| 69 | var buf bytes.Buffer |
| 70 | fmt.Fprint(&buf, pkgIndexHead) |
| 71 | fmt.Fprintf(&buf, "var pkgIndexMaster = %#v\n", pkgIndex) |
| 72 | fmt.Fprintf(&buf, "var exportsMaster = %#v\n", exports) |
| 73 | src := buf.Bytes() |
| 74 | |
| 75 | // Replace main.pkg type name with pkg. |
| 76 | src = bytes.Replace(src, []byte("main.pkg"), []byte("pkg"), -1) |
| 77 | // Replace actual GOROOT with "/go". |
| 78 | src = bytes.Replace(src, []byte(ctx.GOROOT), []byte("/go"), -1) |
| 79 | // Add some line wrapping. |
| 80 | src = bytes.Replace(src, []byte("}, "), []byte("},\n"), -1) |
| 81 | src = bytes.Replace(src, []byte("true, "), []byte("true,\n"), -1) |
| 82 | |
| 83 | var err error |
| 84 | src, err = format.Source(src) |
| 85 | if err != nil { |
| 86 | log.Fatal(err) |
| 87 | } |
| 88 | |
| 89 | // Write out source file. |
| 90 | err = ioutil.WriteFile("pkgindex.go", src, 0644) |
| 91 | if err != nil { |
| 92 | log.Fatal(err) |
| 93 | } |
| 94 | } |
| 95 | |
| 96 | const pkgIndexHead = `package imports |
| 97 | |
| 98 | func init() { |
| 99 | pkgIndexOnce.Do(func() { |
| 100 | pkgIndex.m = pkgIndexMaster |
| 101 | }) |
| 102 | loadExports = func(dir string) map[string]bool { |
| 103 | return exportsMaster[dir] |
| 104 | } |
| 105 | } |
| 106 | ` |
| 107 | |
| 108 | type pkg struct { |
| 109 | importpath string // full pkg import path, e.g. "net/http" |
| 110 | dir string // absolute file path to pkg directory e.g. "/usr/lib/go/src/fmt" |
| 111 | } |
| 112 | |
| 113 | var fset = token.NewFileSet() |
| 114 | |
| 115 | func loadPkg(root, importpath string) { |
| 116 | shortName := path.Base(importpath) |
| 117 | if shortName == "testdata" { |
| 118 | return |
| 119 | } |
| 120 | |
| 121 | dir := filepath.Join(root, importpath) |
| 122 | pkgIndex[shortName] = append(pkgIndex[shortName], pkg{ |
| 123 | importpath: importpath, |
| 124 | dir: dir, |
| 125 | }) |
| 126 | |
| 127 | pkgDir, err := os.Open(dir) |
| 128 | if err != nil { |
| 129 | return |
| 130 | } |
| 131 | children, err := pkgDir.Readdir(-1) |
| 132 | pkgDir.Close() |
| 133 | if err != nil { |
| 134 | return |
| 135 | } |
| 136 | for _, child := range children { |
| 137 | name := child.Name() |
| 138 | if name == "" { |
| 139 | continue |
| 140 | } |
| 141 | if c := name[0]; c == '.' || ('0' <= c && c <= '9') { |
| 142 | continue |
| 143 | } |
| 144 | if child.IsDir() { |
| 145 | loadPkg(root, filepath.Join(importpath, name)) |
| 146 | } |
| 147 | } |
| 148 | } |
| 149 | |
| 150 | func loadExports(dir string) map[string]bool { |
| 151 | exports := make(map[string]bool) |
| 152 | buildPkg, err := build.ImportDir(dir, 0) |
| 153 | if err != nil { |
| 154 | if strings.Contains(err.Error(), "no buildable Go source files in") { |
| 155 | return nil |
| 156 | } |
| 157 | log.Printf("could not import %q: %v", dir, err) |
| 158 | return nil |
| 159 | } |
| 160 | for _, file := range buildPkg.GoFiles { |
| 161 | f, err := parser.ParseFile(fset, filepath.Join(dir, file), nil, 0) |
| 162 | if err != nil { |
| 163 | log.Printf("could not parse %q: %v", file, err) |
| 164 | continue |
| 165 | } |
| 166 | for name := range f.Scope.Objects { |
| 167 | if ast.IsExported(name) { |
| 168 | exports[name] = true |
| 169 | } |
| 170 | } |
| 171 | } |
| 172 | return exports |
| 173 | } |