1 // The eg command performs example-based refactoring.
2 // For documentation, run the command, or see Help in
3 // golang.org/x/tools/refactor/eg.
4 package main // import "golang.org/x/tools/cmd/eg"
17 "golang.org/x/tools/go/buildutil"
18 "golang.org/x/tools/go/loader"
19 "golang.org/x/tools/refactor/eg"
23 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.")
24 helpFlag = flag.Bool("help", false, "show detailed help message")
25 templateFlag = flag.String("t", "", "template.go file specifying the refactoring")
26 transitiveFlag = flag.Bool("transitive", false, "apply refactoring to all dependencies too")
27 writeFlag = flag.Bool("w", false, "rewrite input files in place (by default, the results are printed to standard output)")
28 verboseFlag = flag.Bool("v", false, "show verbose matcher diagnostics")
32 flag.Var((*buildutil.TagsFlag)(&build.Default.BuildTags), "tags", buildutil.TagsFlagDoc)
35 const usage = `eg: an example-based refactoring tool.
37 Usage: eg -t template.go [-w] [-transitive] <args>...
39 -help show detailed help message
40 -t template.go specifies the template file (use -help to see explanation)
41 -w causes files to be re-written in place.
42 -transitive causes all dependencies to be refactored too.
43 -v show verbose matcher diagnostics
44 -beforeedit cmd a command to exec before each file is modified.
45 "{}" represents the name of the file.
46 ` + loader.FromArgsUsage
49 if err := doMain(); err != nil {
50 fmt.Fprintf(os.Stderr, "eg: %s\n", err)
60 fmt.Fprint(os.Stderr, eg.Help)
65 fmt.Fprint(os.Stderr, usage)
69 if *templateFlag == "" {
70 return fmt.Errorf("no -t template.go file specified")
73 conf := loader.Config{
74 Fset: token.NewFileSet(),
75 ParserMode: parser.ParseComments,
78 // The first Created package is the template.
79 conf.CreateFromFilenames("template", *templateFlag)
81 if _, err := conf.FromArgs(args, true); err != nil {
85 // Load, parse and type-check the whole program.
86 iprog, err := conf.Load()
91 // Analyze the template.
92 template := iprog.Created[0]
93 xform, err := eg.NewTransformer(iprog.Fset, template.Pkg, template.Files[0], &template.Info, *verboseFlag)
98 // Apply it to the input packages.
99 var pkgs []*loader.PackageInfo
101 for _, info := range iprog.AllPackages {
102 pkgs = append(pkgs, info)
105 pkgs = iprog.InitialPackages()
108 for _, pkg := range pkgs {
112 for _, file := range pkg.Files {
113 n := xform.Transform(&pkg.Info, pkg.Pkg, file)
117 filename := iprog.Fset.File(file.Pos()).Name()
118 fmt.Fprintf(os.Stderr, "=== %s (%d matches)\n", filename, n)
120 // Run the before-edit command (e.g. "chmod +w", "checkout") if any.
121 if *beforeeditFlag != "" {
122 args := strings.Fields(*beforeeditFlag)
123 // Replace "{}" with the filename, like find(1).
124 for i := range args {
126 args[i] = strings.Replace(args[i], "{}", filename, -1)
129 cmd := exec.Command(args[0], args[1:]...)
130 cmd.Stdout = os.Stdout
131 cmd.Stderr = os.Stderr
132 if err := cmd.Run(); err != nil {
133 fmt.Fprintf(os.Stderr, "Warning: edit hook %q failed (%s)\n",
137 if err := eg.WriteAST(iprog.Fset, filename, file); err != nil {
138 fmt.Fprintf(os.Stderr, "eg: %s\n", err)
142 format.Node(os.Stdout, iprog.Fset, file)