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|
// Copyright 2014 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.
// 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/ast"
"go/format"
"go/parser"
"go/token"
"go/types"
"io/ioutil"
"os"
"path/filepath"
"strings"
exec "golang.org/x/sys/execabs"
"golang.org/x/tools/go/packages"
"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")
)
const usage = `eg: an example-based refactoring tool.
Usage: eg -t template.go [-w] [-transitive] <packages>
-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.
`
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 {
help := eg.Help // hide %s from vet
fmt.Fprint(os.Stderr, 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")
}
tAbs, err := filepath.Abs(*templateFlag)
if err != nil {
return err
}
template, err := ioutil.ReadFile(tAbs)
if err != nil {
return err
}
cfg := &packages.Config{
Fset: token.NewFileSet(),
Mode: packages.NeedTypesInfo | packages.NeedName | packages.NeedTypes | packages.NeedSyntax | packages.NeedImports | packages.NeedDeps | packages.NeedCompiledGoFiles,
Tests: true,
}
pkgs, err := packages.Load(cfg, args...)
if err != nil {
return err
}
tFile, err := parser.ParseFile(cfg.Fset, tAbs, template, parser.ParseComments)
if err != nil {
return err
}
// Type-check the template.
tInfo := types.Info{
Types: make(map[ast.Expr]types.TypeAndValue),
Defs: make(map[*ast.Ident]types.Object),
Uses: make(map[*ast.Ident]types.Object),
Implicits: make(map[ast.Node]types.Object),
Selections: make(map[*ast.SelectorExpr]*types.Selection),
Scopes: make(map[ast.Node]*types.Scope),
}
conf := types.Config{
Importer: pkgsImporter(pkgs),
}
tPkg, err := conf.Check("egtemplate", cfg.Fset, []*ast.File{tFile}, &tInfo)
if err != nil {
return err
}
// Analyze the template.
xform, err := eg.NewTransformer(cfg.Fset, tPkg, tFile, &tInfo, *verboseFlag)
if err != nil {
return err
}
// Apply it to the input packages.
var all []*packages.Package
if *transitiveFlag {
packages.Visit(pkgs, nil, func(p *packages.Package) { all = append(all, p) })
} else {
all = pkgs
}
var hadErrors bool
for _, pkg := range pkgs {
for i, filename := range pkg.CompiledGoFiles {
if filename == tAbs {
// Don't rewrite the template file.
continue
}
file := pkg.Syntax[i]
n := xform.Transform(pkg.TypesInfo, pkg.Types, file)
if n == 0 {
continue
}
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(cfg.Fset, filename, file); err != nil {
fmt.Fprintf(os.Stderr, "eg: %s\n", err)
hadErrors = true
}
} else {
format.Node(os.Stdout, cfg.Fset, file)
}
}
}
if hadErrors {
os.Exit(1)
}
return nil
}
type pkgsImporter []*packages.Package
func (p pkgsImporter) Import(path string) (tpkg *types.Package, err error) {
packages.Visit([]*packages.Package(p), func(pkg *packages.Package) bool {
if pkg.PkgPath == path {
tpkg = pkg.Types
return false
}
return true
}, nil)
if tpkg != nil {
return tpkg, nil
}
return nil, fmt.Errorf("package %q not found", path)
}
|
