+++ /dev/null
-// 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.
-
-package rename
-
-// This file contains logic related to specifying a renaming: parsing of
-// the flags as a form of query, and finding the object(s) it denotes.
-// See Usage for flag details.
-
-import (
- "bytes"
- "fmt"
- "go/ast"
- "go/build"
- "go/parser"
- "go/token"
- "go/types"
- "log"
- "os"
- "path/filepath"
- "regexp"
- "strconv"
- "strings"
-
- "golang.org/x/tools/go/buildutil"
- "golang.org/x/tools/go/loader"
-)
-
-// A spec specifies an entity to rename.
-//
-// It is populated from an -offset flag or -from query;
-// see Usage for the allowed -from query forms.
-//
-type spec struct {
- // pkg is the package containing the position
- // specified by the -from or -offset flag.
- // If filename == "", our search for the 'from' entity
- // is restricted to this package.
- pkg string
-
- // The original name of the entity being renamed.
- // If the query had a ::from component, this is that;
- // otherwise it's the last segment, e.g.
- // (encoding/json.Decoder).from
- // encoding/json.from
- fromName string
-
- // -- The remaining fields are private to this file. All are optional. --
-
- // The query's ::x suffix, if any.
- searchFor string
-
- // e.g. "Decoder" in "(encoding/json.Decoder).fieldOrMethod"
- // or "encoding/json.Decoder
- pkgMember string
-
- // e.g. fieldOrMethod in "(encoding/json.Decoder).fieldOrMethod"
- typeMember string
-
- // Restricts the query to this file.
- // Implied by -from="file.go::x" and -offset flags.
- filename string
-
- // Byte offset of the 'from' identifier within the file named 'filename'.
- // -offset mode only.
- offset int
-}
-
-// parseFromFlag interprets the "-from" flag value as a renaming specification.
-// See Usage in rename.go for valid formats.
-func parseFromFlag(ctxt *build.Context, fromFlag string) (*spec, error) {
- var spec spec
- var main string // sans "::x" suffix
- switch parts := strings.Split(fromFlag, "::"); len(parts) {
- case 1:
- main = parts[0]
- case 2:
- main = parts[0]
- spec.searchFor = parts[1]
- if parts[1] == "" {
- // error
- }
- default:
- return nil, fmt.Errorf("-from %q: invalid identifier specification (see -help for formats)", fromFlag)
- }
-
- if strings.HasSuffix(main, ".go") {
- // main is "filename.go"
- if spec.searchFor == "" {
- return nil, fmt.Errorf("-from: filename %q must have a ::name suffix", main)
- }
- spec.filename = main
- if !buildutil.FileExists(ctxt, spec.filename) {
- return nil, fmt.Errorf("no such file: %s", spec.filename)
- }
-
- bp, err := buildutil.ContainingPackage(ctxt, wd, spec.filename)
- if err != nil {
- return nil, err
- }
- spec.pkg = bp.ImportPath
-
- } else {
- // main is one of:
- // "importpath"
- // "importpath".member
- // (*"importpath".type).fieldormethod (parens and star optional)
- if err := parseObjectSpec(&spec, main); err != nil {
- return nil, err
- }
- }
-
- if spec.searchFor != "" {
- spec.fromName = spec.searchFor
- }
-
- cwd, err := os.Getwd()
- if err != nil {
- return nil, err
- }
-
- // Sanitize the package.
- bp, err := ctxt.Import(spec.pkg, cwd, build.FindOnly)
- if err != nil {
- return nil, fmt.Errorf("can't find package %q", spec.pkg)
- }
- spec.pkg = bp.ImportPath
-
- if !isValidIdentifier(spec.fromName) {
- return nil, fmt.Errorf("-from: invalid identifier %q", spec.fromName)
- }
-
- if Verbose {
- log.Printf("-from spec: %+v", spec)
- }
-
- return &spec, nil
-}
-
-// parseObjectSpec parses main as one of the non-filename forms of
-// object specification.
-func parseObjectSpec(spec *spec, main string) error {
- // Parse main as a Go expression, albeit a strange one.
- e, _ := parser.ParseExpr(main)
-
- if pkg := parseImportPath(e); pkg != "" {
- // e.g. bytes or "encoding/json": a package
- spec.pkg = pkg
- if spec.searchFor == "" {
- return fmt.Errorf("-from %q: package import path %q must have a ::name suffix",
- main, main)
- }
- return nil
- }
-
- if e, ok := e.(*ast.SelectorExpr); ok {
- x := unparen(e.X)
-
- // Strip off star constructor, if any.
- if star, ok := x.(*ast.StarExpr); ok {
- x = star.X
- }
-
- if pkg := parseImportPath(x); pkg != "" {
- // package member e.g. "encoding/json".HTMLEscape
- spec.pkg = pkg // e.g. "encoding/json"
- spec.pkgMember = e.Sel.Name // e.g. "HTMLEscape"
- spec.fromName = e.Sel.Name
- return nil
- }
-
- if x, ok := x.(*ast.SelectorExpr); ok {
- // field/method of type e.g. ("encoding/json".Decoder).Decode
- y := unparen(x.X)
- if pkg := parseImportPath(y); pkg != "" {
- spec.pkg = pkg // e.g. "encoding/json"
- spec.pkgMember = x.Sel.Name // e.g. "Decoder"
- spec.typeMember = e.Sel.Name // e.g. "Decode"
- spec.fromName = e.Sel.Name
- return nil
- }
- }
- }
-
- return fmt.Errorf("-from %q: invalid expression", main)
-}
-
-// parseImportPath returns the import path of the package denoted by e.
-// Any import path may be represented as a string literal;
-// single-segment import paths (e.g. "bytes") may also be represented as
-// ast.Ident. parseImportPath returns "" for all other expressions.
-func parseImportPath(e ast.Expr) string {
- switch e := e.(type) {
- case *ast.Ident:
- return e.Name // e.g. bytes
-
- case *ast.BasicLit:
- if e.Kind == token.STRING {
- pkgname, _ := strconv.Unquote(e.Value)
- return pkgname // e.g. "encoding/json"
- }
- }
- return ""
-}
-
-// parseOffsetFlag interprets the "-offset" flag value as a renaming specification.
-func parseOffsetFlag(ctxt *build.Context, offsetFlag string) (*spec, error) {
- var spec spec
- // Validate -offset, e.g. file.go:#123
- parts := strings.Split(offsetFlag, ":#")
- if len(parts) != 2 {
- return nil, fmt.Errorf("-offset %q: invalid offset specification", offsetFlag)
- }
-
- spec.filename = parts[0]
- if !buildutil.FileExists(ctxt, spec.filename) {
- return nil, fmt.Errorf("no such file: %s", spec.filename)
- }
-
- bp, err := buildutil.ContainingPackage(ctxt, wd, spec.filename)
- if err != nil {
- return nil, err
- }
- spec.pkg = bp.ImportPath
-
- for _, r := range parts[1] {
- if !isDigit(r) {
- return nil, fmt.Errorf("-offset %q: non-numeric offset", offsetFlag)
- }
- }
- spec.offset, err = strconv.Atoi(parts[1])
- if err != nil {
- return nil, fmt.Errorf("-offset %q: non-numeric offset", offsetFlag)
- }
-
- // Parse the file and check there's an identifier at that offset.
- fset := token.NewFileSet()
- f, err := buildutil.ParseFile(fset, ctxt, nil, wd, spec.filename, parser.ParseComments)
- if err != nil {
- return nil, fmt.Errorf("-offset %q: cannot parse file: %s", offsetFlag, err)
- }
-
- id := identAtOffset(fset, f, spec.offset)
- if id == nil {
- return nil, fmt.Errorf("-offset %q: no identifier at this position", offsetFlag)
- }
-
- spec.fromName = id.Name
-
- return &spec, nil
-}
-
-var wd = func() string {
- wd, err := os.Getwd()
- if err != nil {
- panic("cannot get working directory: " + err.Error())
- }
- return wd
-}()
-
-// For source trees built with 'go build', the -from or -offset
-// spec identifies exactly one initial 'from' object to rename ,
-// but certain proprietary build systems allow a single file to
-// appear in multiple packages (e.g. the test package contains a
-// copy of its library), so there may be multiple objects for
-// the same source entity.
-
-func findFromObjects(iprog *loader.Program, spec *spec) ([]types.Object, error) {
- if spec.filename != "" {
- return findFromObjectsInFile(iprog, spec)
- }
-
- // Search for objects defined in specified package.
-
- // TODO(adonovan): the iprog.ImportMap has an entry {"main": ...}
- // for main packages, even though that's not an import path.
- // Seems like a bug.
- //
- // pkg := iprog.ImportMap[spec.pkg]
- // if pkg == nil {
- // return fmt.Errorf("cannot find package %s", spec.pkg) // can't happen?
- // }
- // info := iprog.AllPackages[pkg]
-
- // Workaround: lookup by value.
- var info *loader.PackageInfo
- var pkg *types.Package
- for pkg, info = range iprog.AllPackages {
- if pkg.Path() == spec.pkg {
- break
- }
- }
- if info == nil {
- return nil, fmt.Errorf("package %q was not loaded", spec.pkg)
- }
-
- objects, err := findObjects(info, spec)
- if err != nil {
- return nil, err
- }
- if len(objects) > 1 {
- // ambiguous "*" scope query
- return nil, ambiguityError(iprog.Fset, objects)
- }
- return objects, nil
-}
-
-func findFromObjectsInFile(iprog *loader.Program, spec *spec) ([]types.Object, error) {
- var fromObjects []types.Object
- for _, info := range iprog.AllPackages {
- // restrict to specified filename
- // NB: under certain proprietary build systems, a given
- // filename may appear in multiple packages.
- for _, f := range info.Files {
- thisFile := iprog.Fset.File(f.Pos())
- if !sameFile(thisFile.Name(), spec.filename) {
- continue
- }
- // This package contains the query file.
-
- if spec.offset != 0 {
- // We cannot refactor generated files since position information is invalidated.
- if generated(f, thisFile) {
- return nil, fmt.Errorf("cannot rename identifiers in generated file containing DO NOT EDIT marker: %s", thisFile.Name())
- }
-
- // Search for a specific ident by file/offset.
- id := identAtOffset(iprog.Fset, f, spec.offset)
- if id == nil {
- // can't happen?
- return nil, fmt.Errorf("identifier not found")
- }
- obj := info.Uses[id]
- if obj == nil {
- obj = info.Defs[id]
- if obj == nil {
- // Ident without Object.
-
- // Package clause?
- pos := thisFile.Pos(spec.offset)
- _, path, _ := iprog.PathEnclosingInterval(pos, pos)
- if len(path) == 2 { // [Ident File]
- // TODO(adonovan): support this case.
- return nil, fmt.Errorf("cannot rename %q: renaming package clauses is not yet supported",
- path[1].(*ast.File).Name.Name)
- }
-
- // Implicit y in "switch y := x.(type) {"?
- if obj := typeSwitchVar(&info.Info, path); obj != nil {
- return []types.Object{obj}, nil
- }
-
- // Probably a type error.
- return nil, fmt.Errorf("cannot find object for %q", id.Name)
- }
- }
- if obj.Pkg() == nil {
- return nil, fmt.Errorf("cannot rename predeclared identifiers (%s)", obj)
-
- }
-
- fromObjects = append(fromObjects, obj)
- } else {
- // do a package-wide query
- objects, err := findObjects(info, spec)
- if err != nil {
- return nil, err
- }
-
- // filter results: only objects defined in thisFile
- var filtered []types.Object
- for _, obj := range objects {
- if iprog.Fset.File(obj.Pos()) == thisFile {
- filtered = append(filtered, obj)
- }
- }
- if len(filtered) == 0 {
- return nil, fmt.Errorf("no object %q declared in file %s",
- spec.fromName, spec.filename)
- } else if len(filtered) > 1 {
- return nil, ambiguityError(iprog.Fset, filtered)
- }
- fromObjects = append(fromObjects, filtered[0])
- }
- break
- }
- }
- if len(fromObjects) == 0 {
- // can't happen?
- return nil, fmt.Errorf("file %s was not part of the loaded program", spec.filename)
- }
- return fromObjects, nil
-}
-
-func typeSwitchVar(info *types.Info, path []ast.Node) types.Object {
- if len(path) > 3 {
- // [Ident AssignStmt TypeSwitchStmt...]
- if sw, ok := path[2].(*ast.TypeSwitchStmt); ok {
- // choose the first case.
- if len(sw.Body.List) > 0 {
- obj := info.Implicits[sw.Body.List[0].(*ast.CaseClause)]
- if obj != nil {
- return obj
- }
- }
- }
- }
- return nil
-}
-
-// On success, findObjects returns the list of objects named
-// spec.fromName matching the spec. On success, the result has exactly
-// one element unless spec.searchFor!="", in which case it has at least one
-// element.
-//
-func findObjects(info *loader.PackageInfo, spec *spec) ([]types.Object, error) {
- if spec.pkgMember == "" {
- if spec.searchFor == "" {
- panic(spec)
- }
- objects := searchDefs(&info.Info, spec.searchFor)
- if objects == nil {
- return nil, fmt.Errorf("no object %q declared in package %q",
- spec.searchFor, info.Pkg.Path())
- }
- return objects, nil
- }
-
- pkgMember := info.Pkg.Scope().Lookup(spec.pkgMember)
- if pkgMember == nil {
- return nil, fmt.Errorf("package %q has no member %q",
- info.Pkg.Path(), spec.pkgMember)
- }
-
- var searchFunc *types.Func
- if spec.typeMember == "" {
- // package member
- if spec.searchFor == "" {
- return []types.Object{pkgMember}, nil
- }
-
- // Search within pkgMember, which must be a function.
- searchFunc, _ = pkgMember.(*types.Func)
- if searchFunc == nil {
- return nil, fmt.Errorf("cannot search for %q within %s %q",
- spec.searchFor, objectKind(pkgMember), pkgMember)
- }
- } else {
- // field/method of type
- // e.g. (encoding/json.Decoder).Decode
- // or ::x within it.
-
- tName, _ := pkgMember.(*types.TypeName)
- if tName == nil {
- return nil, fmt.Errorf("%s.%s is a %s, not a type",
- info.Pkg.Path(), pkgMember.Name(), objectKind(pkgMember))
- }
-
- // search within named type.
- obj, _, _ := types.LookupFieldOrMethod(tName.Type(), true, info.Pkg, spec.typeMember)
- if obj == nil {
- return nil, fmt.Errorf("cannot find field or method %q of %s %s.%s",
- spec.typeMember, typeKind(tName.Type()), info.Pkg.Path(), tName.Name())
- }
-
- if spec.searchFor == "" {
- // If it is an embedded field, return the type of the field.
- if v, ok := obj.(*types.Var); ok && v.Anonymous() {
- switch t := v.Type().(type) {
- case *types.Pointer:
- return []types.Object{t.Elem().(*types.Named).Obj()}, nil
- case *types.Named:
- return []types.Object{t.Obj()}, nil
- }
- }
- return []types.Object{obj}, nil
- }
-
- searchFunc, _ = obj.(*types.Func)
- if searchFunc == nil {
- return nil, fmt.Errorf("cannot search for local name %q within %s (%s.%s).%s; need a function",
- spec.searchFor, objectKind(obj), info.Pkg.Path(), tName.Name(),
- obj.Name())
- }
- if isInterface(tName.Type()) {
- return nil, fmt.Errorf("cannot search for local name %q within abstract method (%s.%s).%s",
- spec.searchFor, info.Pkg.Path(), tName.Name(), searchFunc.Name())
- }
- }
-
- // -- search within function or method --
-
- decl := funcDecl(info, searchFunc)
- if decl == nil {
- return nil, fmt.Errorf("cannot find syntax for %s", searchFunc) // can't happen?
- }
-
- var objects []types.Object
- for _, obj := range searchDefs(&info.Info, spec.searchFor) {
- // We use positions, not scopes, to determine whether
- // the obj is within searchFunc. This is clumsy, but the
- // alternative, using the types.Scope tree, doesn't
- // account for non-lexical objects like fields and
- // interface methods.
- if decl.Pos() <= obj.Pos() && obj.Pos() < decl.End() && obj != searchFunc {
- objects = append(objects, obj)
- }
- }
- if objects == nil {
- return nil, fmt.Errorf("no local definition of %q within %s",
- spec.searchFor, searchFunc)
- }
- return objects, nil
-}
-
-func funcDecl(info *loader.PackageInfo, fn *types.Func) *ast.FuncDecl {
- for _, f := range info.Files {
- for _, d := range f.Decls {
- if d, ok := d.(*ast.FuncDecl); ok && info.Defs[d.Name] == fn {
- return d
- }
- }
- }
- return nil
-}
-
-func searchDefs(info *types.Info, name string) []types.Object {
- var objects []types.Object
- for id, obj := range info.Defs {
- if obj == nil {
- // e.g. blank ident.
- // TODO(adonovan): but also implicit y in
- // switch y := x.(type)
- // Needs some thought.
- continue
- }
- if id.Name == name {
- objects = append(objects, obj)
- }
- }
- return objects
-}
-
-func identAtOffset(fset *token.FileSet, f *ast.File, offset int) *ast.Ident {
- var found *ast.Ident
- ast.Inspect(f, func(n ast.Node) bool {
- if id, ok := n.(*ast.Ident); ok {
- idpos := fset.Position(id.Pos()).Offset
- if idpos <= offset && offset < idpos+len(id.Name) {
- found = id
- }
- }
- return found == nil // keep traversing only until found
- })
- return found
-}
-
-// ambiguityError returns an error describing an ambiguous "*" scope query.
-func ambiguityError(fset *token.FileSet, objects []types.Object) error {
- var buf bytes.Buffer
- for i, obj := range objects {
- if i > 0 {
- buf.WriteString(", ")
- }
- posn := fset.Position(obj.Pos())
- fmt.Fprintf(&buf, "%s at %s:%d:%d",
- objectKind(obj), filepath.Base(posn.Filename), posn.Line, posn.Column)
- }
- return fmt.Errorf("ambiguous specifier %s matches %s",
- objects[0].Name(), buf.String())
-}
-
-// Matches cgo generated comment as well as the proposed standard:
-// https://golang.org/s/generatedcode
-var generatedRx = regexp.MustCompile(`// .*DO NOT EDIT\.?`)
-
-// generated reports whether ast.File is a generated file.
-func generated(f *ast.File, tokenFile *token.File) bool {
-
- // Iterate over the comments in the file
- for _, commentGroup := range f.Comments {
- for _, comment := range commentGroup.List {
- if matched := generatedRx.MatchString(comment.Text); matched {
- // Check if comment is at the beginning of the line in source
- if pos := tokenFile.Position(comment.Slash); pos.Column == 1 {
- return true
- }
- }
- }
- }
- return false
-}
projects / dotfiles / .git / blobdiff