| // Copyright 2015 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. |
| |
| // This file contains the implementation of the 'gomvpkg' command |
| // whose main function is in golang.org/x/tools/cmd/gomvpkg. |
| |
| package rename |
| |
| // TODO(matloob): |
| // - think about what happens if the package is moving across version control systems. |
| // - dot imports are not supported. Make sure it's clearly documented. |
| |
| import ( |
| "bytes" |
| "fmt" |
| "go/ast" |
| "go/build" |
| "go/format" |
| "go/token" |
| "log" |
| "os" |
| "os/exec" |
| "path" |
| "path/filepath" |
| "regexp" |
| "runtime" |
| "strconv" |
| "strings" |
| "text/template" |
| |
| "golang.org/x/tools/go/buildutil" |
| "golang.org/x/tools/go/loader" |
| "golang.org/x/tools/refactor/importgraph" |
| ) |
| |
| // Move, given a package path and a destination package path, will try |
| // to move the given package to the new path. The Move function will |
| // first check for any conflicts preventing the move, such as a |
| // package already existing at the destination package path. If the |
| // move can proceed, it builds an import graph to find all imports of |
| // the packages whose paths need to be renamed. This includes uses of |
| // the subpackages of the package to be moved as those packages will |
| // also need to be moved. It then renames all imports to point to the |
| // new paths, and then moves the packages to their new paths. |
| func Move(ctxt *build.Context, from, to, moveTmpl string) error { |
| srcDir, err := srcDir(ctxt, from) |
| if err != nil { |
| return err |
| } |
| |
| // This should be the only place in the program that constructs |
| // file paths. |
| fromDir := buildutil.JoinPath(ctxt, srcDir, filepath.FromSlash(from)) |
| toDir := buildutil.JoinPath(ctxt, srcDir, filepath.FromSlash(to)) |
| toParent := filepath.Dir(toDir) |
| if !buildutil.IsDir(ctxt, toParent) { |
| return fmt.Errorf("parent directory does not exist for path %s", toDir) |
| } |
| |
| // Build the import graph and figure out which packages to update. |
| _, rev, errors := importgraph.Build(ctxt) |
| if len(errors) > 0 { |
| // With a large GOPATH tree, errors are inevitable. |
| // Report them but proceed. |
| fmt.Fprintf(os.Stderr, "While scanning Go workspace:\n") |
| for path, err := range errors { |
| fmt.Fprintf(os.Stderr, "Package %q: %s.\n", path, err) |
| } |
| } |
| |
| // Determine the affected packages---the set of packages whose import |
| // statements need updating. |
| affectedPackages := map[string]bool{from: true} |
| destinations := make(map[string]string) // maps old import path to new import path |
| for pkg := range subpackages(ctxt, srcDir, from) { |
| for r := range rev[pkg] { |
| affectedPackages[r] = true |
| } |
| destinations[pkg] = strings.Replace(pkg, from, to, 1) |
| } |
| |
| // Load all the affected packages. |
| iprog, err := loadProgram(ctxt, affectedPackages) |
| if err != nil { |
| return err |
| } |
| |
| // Prepare the move command, if one was supplied. |
| var cmd string |
| if moveTmpl != "" { |
| if cmd, err = moveCmd(moveTmpl, fromDir, toDir); err != nil { |
| return err |
| } |
| } |
| |
| m := mover{ |
| ctxt: ctxt, |
| rev: rev, |
| iprog: iprog, |
| from: from, |
| to: to, |
| fromDir: fromDir, |
| toDir: toDir, |
| affectedPackages: affectedPackages, |
| destinations: destinations, |
| cmd: cmd, |
| } |
| |
| if err := m.checkValid(); err != nil { |
| return err |
| } |
| |
| m.move() |
| |
| return nil |
| } |
| |
| // srcDir returns the absolute path of the srcdir containing pkg. |
| func srcDir(ctxt *build.Context, pkg string) (string, error) { |
| for _, srcDir := range ctxt.SrcDirs() { |
| path := buildutil.JoinPath(ctxt, srcDir, pkg) |
| if buildutil.IsDir(ctxt, path) { |
| return srcDir, nil |
| } |
| } |
| return "", fmt.Errorf("src dir not found for package: %s", pkg) |
| } |
| |
| // subpackages returns the set of packages in the given srcDir whose |
| // import path equals to root, or has "root/" as the prefix. |
| func subpackages(ctxt *build.Context, srcDir string, root string) map[string]bool { |
| var subs = make(map[string]bool) |
| buildutil.ForEachPackage(ctxt, func(pkg string, err error) { |
| if err != nil { |
| log.Fatalf("unexpected error in ForEachPackage: %v", err) |
| } |
| |
| // Only process the package root, or a sub-package of it. |
| if !(strings.HasPrefix(pkg, root) && |
| (len(pkg) == len(root) || pkg[len(root)] == '/')) { |
| return |
| } |
| |
| p, err := ctxt.Import(pkg, "", build.FindOnly) |
| if err != nil { |
| log.Fatalf("unexpected: package %s can not be located by build context: %s", pkg, err) |
| } |
| if p.SrcRoot == "" { |
| log.Fatalf("unexpected: could not determine srcDir for package %s: %s", pkg, err) |
| } |
| if p.SrcRoot != srcDir { |
| return |
| } |
| |
| subs[pkg] = true |
| }) |
| return subs |
| } |
| |
| type mover struct { |
| // iprog contains all packages whose contents need to be updated |
| // with new package names or import paths. |
| iprog *loader.Program |
| ctxt *build.Context |
| // rev is the reverse import graph. |
| rev importgraph.Graph |
| // from and to are the source and destination import |
| // paths. fromDir and toDir are the source and destination |
| // absolute paths that package source files will be moved between. |
| from, to, fromDir, toDir string |
| // affectedPackages is the set of all packages whose contents need |
| // to be updated to reflect new package names or import paths. |
| affectedPackages map[string]bool |
| // destinations maps each subpackage to be moved to its |
| // destination path. |
| destinations map[string]string |
| // cmd, if not empty, will be executed to move fromDir to toDir. |
| cmd string |
| } |
| |
| func (m *mover) checkValid() error { |
| const prefix = "invalid move destination" |
| |
| match, err := regexp.MatchString("^[_\\pL][_\\pL\\p{Nd}]*$", path.Base(m.to)) |
| if err != nil { |
| panic("regexp.MatchString failed") |
| } |
| if !match { |
| return fmt.Errorf("%s: %s; gomvpkg does not support move destinations "+ |
| "whose base names are not valid go identifiers", prefix, m.to) |
| } |
| |
| if buildutil.FileExists(m.ctxt, m.toDir) { |
| return fmt.Errorf("%s: %s conflicts with file %s", prefix, m.to, m.toDir) |
| } |
| if buildutil.IsDir(m.ctxt, m.toDir) { |
| return fmt.Errorf("%s: %s conflicts with directory %s", prefix, m.to, m.toDir) |
| } |
| |
| for _, toSubPkg := range m.destinations { |
| if _, err := m.ctxt.Import(toSubPkg, "", build.FindOnly); err == nil { |
| return fmt.Errorf("%s: %s; package or subpackage %s already exists", |
| prefix, m.to, toSubPkg) |
| } |
| } |
| |
| return nil |
| } |
| |
| // moveCmd produces the version control move command used to move fromDir to toDir by |
| // executing the given template. |
| func moveCmd(moveTmpl, fromDir, toDir string) (string, error) { |
| tmpl, err := template.New("movecmd").Parse(moveTmpl) |
| if err != nil { |
| return "", err |
| } |
| |
| var buf bytes.Buffer |
| err = tmpl.Execute(&buf, struct { |
| Src string |
| Dst string |
| }{fromDir, toDir}) |
| return buf.String(), err |
| } |
| |
| func (m *mover) move() error { |
| filesToUpdate := make(map[*ast.File]bool) |
| |
| // Change the moved package's "package" declaration to its new base name. |
| pkg, ok := m.iprog.Imported[m.from] |
| if !ok { |
| log.Fatalf("unexpected: package %s is not in import map", m.from) |
| } |
| newName := filepath.Base(m.to) |
| for _, f := range pkg.Files { |
| // Update all import comments. |
| for _, cg := range f.Comments { |
| c := cg.List[0] |
| if c.Slash >= f.Name.End() && |
| sameLine(m.iprog.Fset, c.Slash, f.Name.End()) && |
| (f.Decls == nil || c.Slash < f.Decls[0].Pos()) { |
| if strings.HasPrefix(c.Text, `// import "`) { |
| c.Text = `// import "` + m.to + `"` |
| break |
| } |
| if strings.HasPrefix(c.Text, `/* import "`) { |
| c.Text = `/* import "` + m.to + `" */` |
| break |
| } |
| } |
| } |
| f.Name.Name = newName // change package decl |
| filesToUpdate[f] = true |
| } |
| |
| // Look through the external test packages (m.iprog.Created contains the external test packages). |
| for _, info := range m.iprog.Created { |
| // Change the "package" declaration of the external test package. |
| if info.Pkg.Path() == m.from+"_test" { |
| for _, f := range info.Files { |
| f.Name.Name = newName + "_test" // change package decl |
| filesToUpdate[f] = true |
| } |
| } |
| |
| // Mark all the loaded external test packages, which import the "from" package, |
| // as affected packages and update the imports. |
| for _, imp := range info.Pkg.Imports() { |
| if imp.Path() == m.from { |
| m.affectedPackages[info.Pkg.Path()] = true |
| m.iprog.Imported[info.Pkg.Path()] = info |
| if err := importName(m.iprog, info, m.from, path.Base(m.from), newName); err != nil { |
| return err |
| } |
| } |
| } |
| } |
| |
| // Update imports of that package to use the new import name. |
| // None of the subpackages will change their name---only the from package |
| // itself will. |
| for p := range m.rev[m.from] { |
| if err := importName(m.iprog, m.iprog.Imported[p], m.from, path.Base(m.from), newName); err != nil { |
| return err |
| } |
| } |
| |
| // Update import paths for all imports by affected packages. |
| for ap := range m.affectedPackages { |
| info, ok := m.iprog.Imported[ap] |
| if !ok { |
| log.Fatalf("unexpected: package %s is not in import map", ap) |
| } |
| for _, f := range info.Files { |
| for _, imp := range f.Imports { |
| importPath, _ := strconv.Unquote(imp.Path.Value) |
| if newPath, ok := m.destinations[importPath]; ok { |
| imp.Path.Value = strconv.Quote(newPath) |
| |
| oldName := path.Base(importPath) |
| if imp.Name != nil { |
| oldName = imp.Name.Name |
| } |
| |
| newName := path.Base(newPath) |
| if imp.Name == nil && oldName != newName { |
| imp.Name = ast.NewIdent(oldName) |
| } else if imp.Name == nil || imp.Name.Name == newName { |
| imp.Name = nil |
| } |
| filesToUpdate[f] = true |
| } |
| } |
| } |
| } |
| |
| for f := range filesToUpdate { |
| var buf bytes.Buffer |
| if err := format.Node(&buf, m.iprog.Fset, f); err != nil { |
| log.Printf("failed to pretty-print syntax tree: %v", err) |
| continue |
| } |
| tokenFile := m.iprog.Fset.File(f.Pos()) |
| writeFile(tokenFile.Name(), buf.Bytes()) |
| } |
| |
| // Move the directories. |
| // If either the fromDir or toDir are contained under version control it is |
| // the user's responsibility to provide a custom move command that updates |
| // version control to reflect the move. |
| // TODO(matloob): If the parent directory of toDir does not exist, create it. |
| // For now, it's required that it does exist. |
| |
| if m.cmd != "" { |
| // TODO(matloob): Verify that the windows and plan9 cases are correct. |
| var cmd *exec.Cmd |
| switch runtime.GOOS { |
| case "windows": |
| cmd = exec.Command("cmd", "/c", m.cmd) |
| case "plan9": |
| cmd = exec.Command("rc", "-c", m.cmd) |
| default: |
| cmd = exec.Command("sh", "-c", m.cmd) |
| } |
| cmd.Stderr = os.Stderr |
| cmd.Stdout = os.Stdout |
| if err := cmd.Run(); err != nil { |
| return fmt.Errorf("version control system's move command failed: %v", err) |
| } |
| |
| return nil |
| } |
| |
| return moveDirectory(m.fromDir, m.toDir) |
| } |
| |
| // sameLine reports whether two positions in the same file are on the same line. |
| func sameLine(fset *token.FileSet, x, y token.Pos) bool { |
| return fset.Position(x).Line == fset.Position(y).Line |
| } |
| |
| var moveDirectory = func(from, to string) error { |
| return os.Rename(from, to) |
| } |