1 // Copyright 2014 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
5 // The eg command performs example-based refactoring.
6 // For documentation, run the command, or see Help in
7 // golang.org/x/tools/refactor/eg.
8 package main // import "golang.org/x/tools/cmd/eg"
23 exec "golang.org/x/sys/execabs"
24 "golang.org/x/tools/go/packages"
25 "golang.org/x/tools/refactor/eg"
29 beforeeditFlag = flag.String("beforeedit", "", "A command to exec before each file is edited (e.g. chmod, checkout). Whitespace delimits argument words. The string '{}' is replaced by the file name.")
30 helpFlag = flag.Bool("help", false, "show detailed help message")
31 templateFlag = flag.String("t", "", "template.go file specifying the refactoring")
32 transitiveFlag = flag.Bool("transitive", false, "apply refactoring to all dependencies too")
33 writeFlag = flag.Bool("w", false, "rewrite input files in place (by default, the results are printed to standard output)")
34 verboseFlag = flag.Bool("v", false, "show verbose matcher diagnostics")
37 const usage = `eg: an example-based refactoring tool.
39 Usage: eg -t template.go [-w] [-transitive] <packages>
41 -help show detailed help message
42 -t template.go specifies the template file (use -help to see explanation)
43 -w causes files to be re-written in place.
44 -transitive causes all dependencies to be refactored too.
45 -v show verbose matcher diagnostics
46 -beforeedit cmd a command to exec before each file is modified.
47 "{}" represents the name of the file.
51 if err := doMain(); err != nil {
52 fmt.Fprintf(os.Stderr, "eg: %s\n", err)
62 fmt.Fprint(os.Stderr, eg.Help)
67 fmt.Fprint(os.Stderr, usage)
71 if *templateFlag == "" {
72 return fmt.Errorf("no -t template.go file specified")
75 tAbs, err := filepath.Abs(*templateFlag)
79 template, err := ioutil.ReadFile(tAbs)
84 cfg := &packages.Config{
85 Fset: token.NewFileSet(),
86 Mode: packages.NeedTypesInfo | packages.NeedName | packages.NeedTypes | packages.NeedSyntax | packages.NeedImports | packages.NeedDeps | packages.NeedCompiledGoFiles,
90 pkgs, err := packages.Load(cfg, args...)
95 tFile, err := parser.ParseFile(cfg.Fset, tAbs, template, parser.ParseComments)
100 // Type-check the template.
102 Types: make(map[ast.Expr]types.TypeAndValue),
103 Defs: make(map[*ast.Ident]types.Object),
104 Uses: make(map[*ast.Ident]types.Object),
105 Implicits: make(map[ast.Node]types.Object),
106 Selections: make(map[*ast.SelectorExpr]*types.Selection),
107 Scopes: make(map[ast.Node]*types.Scope),
109 conf := types.Config{
110 Importer: pkgsImporter(pkgs),
112 tPkg, err := conf.Check("egtemplate", cfg.Fset, []*ast.File{tFile}, &tInfo)
117 // Analyze the template.
118 xform, err := eg.NewTransformer(cfg.Fset, tPkg, tFile, &tInfo, *verboseFlag)
123 // Apply it to the input packages.
124 var all []*packages.Package
126 packages.Visit(pkgs, nil, func(p *packages.Package) { all = append(all, p) })
131 for _, pkg := range pkgs {
132 for i, filename := range pkg.CompiledGoFiles {
133 if filename == tAbs {
134 // Don't rewrite the template file.
137 file := pkg.Syntax[i]
138 n := xform.Transform(pkg.TypesInfo, pkg.Types, file)
142 fmt.Fprintf(os.Stderr, "=== %s (%d matches)\n", filename, n)
144 // Run the before-edit command (e.g. "chmod +w", "checkout") if any.
145 if *beforeeditFlag != "" {
146 args := strings.Fields(*beforeeditFlag)
147 // Replace "{}" with the filename, like find(1).
148 for i := range args {
150 args[i] = strings.Replace(args[i], "{}", filename, -1)
153 cmd := exec.Command(args[0], args[1:]...)
154 cmd.Stdout = os.Stdout
155 cmd.Stderr = os.Stderr
156 if err := cmd.Run(); err != nil {
157 fmt.Fprintf(os.Stderr, "Warning: edit hook %q failed (%s)\n",
161 if err := eg.WriteAST(cfg.Fset, filename, file); err != nil {
162 fmt.Fprintf(os.Stderr, "eg: %s\n", err)
166 format.Node(os.Stdout, cfg.Fset, file)
177 type pkgsImporter []*packages.Package
179 func (p pkgsImporter) Import(path string) (tpkg *types.Package, err error) {
180 packages.Visit([]*packages.Package(p), func(pkg *packages.Package) bool {
181 if pkg.PkgPath == path {
190 return nil, fmt.Errorf("package %q not found", path)