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// The eg command performs example-based refactoring.
// For documentation, run the command, or see Help in
// golang.org/x/tools/refactor/eg.
package main // import "golang.org/x/tools/cmd/eg"
import (
"flag"
"fmt"
"go/build"
"go/format"
"go/parser"
"go/token"
"os"
"os/exec"
"strings"
"golang.org/x/tools/go/buildutil"
"golang.org/x/tools/go/loader"
"golang.org/x/tools/refactor/eg"
)
var (
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.")
helpFlag = flag.Bool("help", false, "show detailed help message")
templateFlag = flag.String("t", "", "template.go file specifying the refactoring")
transitiveFlag = flag.Bool("transitive", false, "apply refactoring to all dependencies too")
writeFlag = flag.Bool("w", false, "rewrite input files in place (by default, the results are printed to standard output)")
verboseFlag = flag.Bool("v", false, "show verbose matcher diagnostics")
)
func init() {
flag.Var((*buildutil.TagsFlag)(&build.Default.BuildTags), "tags", buildutil.TagsFlagDoc)
}
const usage = `eg: an example-based refactoring tool.
Usage: eg -t template.go [-w] [-transitive] <args>...
-help show detailed help message
-t template.go specifies the template file (use -help to see explanation)
-w causes files to be re-written in place.
-transitive causes all dependencies to be refactored too.
-v show verbose matcher diagnostics
-beforeedit cmd a command to exec before each file is modified.
"{}" represents the name of the file.
` + loader.FromArgsUsage
func main() {
if err := doMain(); err != nil {
fmt.Fprintf(os.Stderr, "eg: %s\n", err)
os.Exit(1)
}
}
func doMain() error {
flag.Parse()
args := flag.Args()
if *helpFlag {
fmt.Fprint(os.Stderr, eg.Help)
os.Exit(2)
}
if len(args) == 0 {
fmt.Fprint(os.Stderr, usage)
os.Exit(1)
}
if *templateFlag == "" {
return fmt.Errorf("no -t template.go file specified")
}
conf := loader.Config{
Fset: token.NewFileSet(),
ParserMode: parser.ParseComments,
}
// The first Created package is the template.
conf.CreateFromFilenames("template", *templateFlag)
if _, err := conf.FromArgs(args, true); err != nil {
return err
}
// Load, parse and type-check the whole program.
iprog, err := conf.Load()
if err != nil {
return err
}
// Analyze the template.
template := iprog.Created[0]
xform, err := eg.NewTransformer(iprog.Fset, template.Pkg, template.Files[0], &template.Info, *verboseFlag)
if err != nil {
return err
}
// Apply it to the input packages.
var pkgs []*loader.PackageInfo
if *transitiveFlag {
for _, info := range iprog.AllPackages {
pkgs = append(pkgs, info)
}
} else {
pkgs = iprog.InitialPackages()
}
var hadErrors bool
for _, pkg := range pkgs {
if pkg == template {
continue
}
for _, file := range pkg.Files {
n := xform.Transform(&pkg.Info, pkg.Pkg, file)
if n == 0 {
continue
}
filename := iprog.Fset.File(file.Pos()).Name()
fmt.Fprintf(os.Stderr, "=== %s (%d matches)\n", filename, n)
if *writeFlag {
// Run the before-edit command (e.g. "chmod +w", "checkout") if any.
if *beforeeditFlag != "" {
args := strings.Fields(*beforeeditFlag)
// Replace "{}" with the filename, like find(1).
for i := range args {
if i > 0 {
args[i] = strings.Replace(args[i], "{}", filename, -1)
}
}
cmd := exec.Command(args[0], args[1:]...)
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
if err := cmd.Run(); err != nil {
fmt.Fprintf(os.Stderr, "Warning: edit hook %q failed (%s)\n",
args, err)
}
}
if err := eg.WriteAST(iprog.Fset, filename, file); err != nil {
fmt.Fprintf(os.Stderr, "eg: %s\n", err)
hadErrors = true
}
} else {
format.Node(os.Stdout, iprog.Fset, file)
}
}
}
if hadErrors {
os.Exit(1)
}
return nil
}
|
