summaryrefslogtreecommitdiff
path: root/src/cmd/fix/fix.go
diff options
context:
space:
mode:
Diffstat (limited to 'src/cmd/fix/fix.go')
-rw-r--r--src/cmd/fix/fix.go848
1 files changed, 848 insertions, 0 deletions
diff --git a/src/cmd/fix/fix.go b/src/cmd/fix/fix.go
new file mode 100644
index 000000000..a100be794
--- /dev/null
+++ b/src/cmd/fix/fix.go
@@ -0,0 +1,848 @@
+// Copyright 2011 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 main
+
+import (
+ "fmt"
+ "go/ast"
+ "go/parser"
+ "go/token"
+ "os"
+ "path"
+ "reflect"
+ "strconv"
+ "strings"
+)
+
+type fix struct {
+ name string
+ date string // date that fix was introduced, in YYYY-MM-DD format
+ f func(*ast.File) bool
+ desc string
+}
+
+// main runs sort.Sort(byName(fixes)) before printing list of fixes.
+type byName []fix
+
+func (f byName) Len() int { return len(f) }
+func (f byName) Swap(i, j int) { f[i], f[j] = f[j], f[i] }
+func (f byName) Less(i, j int) bool { return f[i].name < f[j].name }
+
+// main runs sort.Sort(byDate(fixes)) before applying fixes.
+type byDate []fix
+
+func (f byDate) Len() int { return len(f) }
+func (f byDate) Swap(i, j int) { f[i], f[j] = f[j], f[i] }
+func (f byDate) Less(i, j int) bool { return f[i].date < f[j].date }
+
+var fixes []fix
+
+func register(f fix) {
+ fixes = append(fixes, f)
+}
+
+// walk traverses the AST x, calling visit(y) for each node y in the tree but
+// also with a pointer to each ast.Expr, ast.Stmt, and *ast.BlockStmt,
+// in a bottom-up traversal.
+func walk(x interface{}, visit func(interface{})) {
+ walkBeforeAfter(x, nop, visit)
+}
+
+func nop(interface{}) {}
+
+// walkBeforeAfter is like walk but calls before(x) before traversing
+// x's children and after(x) afterward.
+func walkBeforeAfter(x interface{}, before, after func(interface{})) {
+ before(x)
+
+ switch n := x.(type) {
+ default:
+ panic(fmt.Errorf("unexpected type %T in walkBeforeAfter", x))
+
+ case nil:
+
+ // pointers to interfaces
+ case *ast.Decl:
+ walkBeforeAfter(*n, before, after)
+ case *ast.Expr:
+ walkBeforeAfter(*n, before, after)
+ case *ast.Spec:
+ walkBeforeAfter(*n, before, after)
+ case *ast.Stmt:
+ walkBeforeAfter(*n, before, after)
+
+ // pointers to struct pointers
+ case **ast.BlockStmt:
+ walkBeforeAfter(*n, before, after)
+ case **ast.CallExpr:
+ walkBeforeAfter(*n, before, after)
+ case **ast.FieldList:
+ walkBeforeAfter(*n, before, after)
+ case **ast.FuncType:
+ walkBeforeAfter(*n, before, after)
+ case **ast.Ident:
+ walkBeforeAfter(*n, before, after)
+ case **ast.BasicLit:
+ walkBeforeAfter(*n, before, after)
+
+ // pointers to slices
+ case *[]ast.Decl:
+ walkBeforeAfter(*n, before, after)
+ case *[]ast.Expr:
+ walkBeforeAfter(*n, before, after)
+ case *[]*ast.File:
+ walkBeforeAfter(*n, before, after)
+ case *[]*ast.Ident:
+ walkBeforeAfter(*n, before, after)
+ case *[]ast.Spec:
+ walkBeforeAfter(*n, before, after)
+ case *[]ast.Stmt:
+ walkBeforeAfter(*n, before, after)
+
+ // These are ordered and grouped to match ../../pkg/go/ast/ast.go
+ case *ast.Field:
+ walkBeforeAfter(&n.Names, before, after)
+ walkBeforeAfter(&n.Type, before, after)
+ walkBeforeAfter(&n.Tag, before, after)
+ case *ast.FieldList:
+ for _, field := range n.List {
+ walkBeforeAfter(field, before, after)
+ }
+ case *ast.BadExpr:
+ case *ast.Ident:
+ case *ast.Ellipsis:
+ walkBeforeAfter(&n.Elt, before, after)
+ case *ast.BasicLit:
+ case *ast.FuncLit:
+ walkBeforeAfter(&n.Type, before, after)
+ walkBeforeAfter(&n.Body, before, after)
+ case *ast.CompositeLit:
+ walkBeforeAfter(&n.Type, before, after)
+ walkBeforeAfter(&n.Elts, before, after)
+ case *ast.ParenExpr:
+ walkBeforeAfter(&n.X, before, after)
+ case *ast.SelectorExpr:
+ walkBeforeAfter(&n.X, before, after)
+ case *ast.IndexExpr:
+ walkBeforeAfter(&n.X, before, after)
+ walkBeforeAfter(&n.Index, before, after)
+ case *ast.SliceExpr:
+ walkBeforeAfter(&n.X, before, after)
+ if n.Low != nil {
+ walkBeforeAfter(&n.Low, before, after)
+ }
+ if n.High != nil {
+ walkBeforeAfter(&n.High, before, after)
+ }
+ case *ast.TypeAssertExpr:
+ walkBeforeAfter(&n.X, before, after)
+ walkBeforeAfter(&n.Type, before, after)
+ case *ast.CallExpr:
+ walkBeforeAfter(&n.Fun, before, after)
+ walkBeforeAfter(&n.Args, before, after)
+ case *ast.StarExpr:
+ walkBeforeAfter(&n.X, before, after)
+ case *ast.UnaryExpr:
+ walkBeforeAfter(&n.X, before, after)
+ case *ast.BinaryExpr:
+ walkBeforeAfter(&n.X, before, after)
+ walkBeforeAfter(&n.Y, before, after)
+ case *ast.KeyValueExpr:
+ walkBeforeAfter(&n.Key, before, after)
+ walkBeforeAfter(&n.Value, before, after)
+
+ case *ast.ArrayType:
+ walkBeforeAfter(&n.Len, before, after)
+ walkBeforeAfter(&n.Elt, before, after)
+ case *ast.StructType:
+ walkBeforeAfter(&n.Fields, before, after)
+ case *ast.FuncType:
+ walkBeforeAfter(&n.Params, before, after)
+ if n.Results != nil {
+ walkBeforeAfter(&n.Results, before, after)
+ }
+ case *ast.InterfaceType:
+ walkBeforeAfter(&n.Methods, before, after)
+ case *ast.MapType:
+ walkBeforeAfter(&n.Key, before, after)
+ walkBeforeAfter(&n.Value, before, after)
+ case *ast.ChanType:
+ walkBeforeAfter(&n.Value, before, after)
+
+ case *ast.BadStmt:
+ case *ast.DeclStmt:
+ walkBeforeAfter(&n.Decl, before, after)
+ case *ast.EmptyStmt:
+ case *ast.LabeledStmt:
+ walkBeforeAfter(&n.Stmt, before, after)
+ case *ast.ExprStmt:
+ walkBeforeAfter(&n.X, before, after)
+ case *ast.SendStmt:
+ walkBeforeAfter(&n.Chan, before, after)
+ walkBeforeAfter(&n.Value, before, after)
+ case *ast.IncDecStmt:
+ walkBeforeAfter(&n.X, before, after)
+ case *ast.AssignStmt:
+ walkBeforeAfter(&n.Lhs, before, after)
+ walkBeforeAfter(&n.Rhs, before, after)
+ case *ast.GoStmt:
+ walkBeforeAfter(&n.Call, before, after)
+ case *ast.DeferStmt:
+ walkBeforeAfter(&n.Call, before, after)
+ case *ast.ReturnStmt:
+ walkBeforeAfter(&n.Results, before, after)
+ case *ast.BranchStmt:
+ case *ast.BlockStmt:
+ walkBeforeAfter(&n.List, before, after)
+ case *ast.IfStmt:
+ walkBeforeAfter(&n.Init, before, after)
+ walkBeforeAfter(&n.Cond, before, after)
+ walkBeforeAfter(&n.Body, before, after)
+ walkBeforeAfter(&n.Else, before, after)
+ case *ast.CaseClause:
+ walkBeforeAfter(&n.List, before, after)
+ walkBeforeAfter(&n.Body, before, after)
+ case *ast.SwitchStmt:
+ walkBeforeAfter(&n.Init, before, after)
+ walkBeforeAfter(&n.Tag, before, after)
+ walkBeforeAfter(&n.Body, before, after)
+ case *ast.TypeSwitchStmt:
+ walkBeforeAfter(&n.Init, before, after)
+ walkBeforeAfter(&n.Assign, before, after)
+ walkBeforeAfter(&n.Body, before, after)
+ case *ast.CommClause:
+ walkBeforeAfter(&n.Comm, before, after)
+ walkBeforeAfter(&n.Body, before, after)
+ case *ast.SelectStmt:
+ walkBeforeAfter(&n.Body, before, after)
+ case *ast.ForStmt:
+ walkBeforeAfter(&n.Init, before, after)
+ walkBeforeAfter(&n.Cond, before, after)
+ walkBeforeAfter(&n.Post, before, after)
+ walkBeforeAfter(&n.Body, before, after)
+ case *ast.RangeStmt:
+ walkBeforeAfter(&n.Key, before, after)
+ walkBeforeAfter(&n.Value, before, after)
+ walkBeforeAfter(&n.X, before, after)
+ walkBeforeAfter(&n.Body, before, after)
+
+ case *ast.ImportSpec:
+ case *ast.ValueSpec:
+ walkBeforeAfter(&n.Type, before, after)
+ walkBeforeAfter(&n.Values, before, after)
+ walkBeforeAfter(&n.Names, before, after)
+ case *ast.TypeSpec:
+ walkBeforeAfter(&n.Type, before, after)
+
+ case *ast.BadDecl:
+ case *ast.GenDecl:
+ walkBeforeAfter(&n.Specs, before, after)
+ case *ast.FuncDecl:
+ if n.Recv != nil {
+ walkBeforeAfter(&n.Recv, before, after)
+ }
+ walkBeforeAfter(&n.Type, before, after)
+ if n.Body != nil {
+ walkBeforeAfter(&n.Body, before, after)
+ }
+
+ case *ast.File:
+ walkBeforeAfter(&n.Decls, before, after)
+
+ case *ast.Package:
+ walkBeforeAfter(&n.Files, before, after)
+
+ case []*ast.File:
+ for i := range n {
+ walkBeforeAfter(&n[i], before, after)
+ }
+ case []ast.Decl:
+ for i := range n {
+ walkBeforeAfter(&n[i], before, after)
+ }
+ case []ast.Expr:
+ for i := range n {
+ walkBeforeAfter(&n[i], before, after)
+ }
+ case []*ast.Ident:
+ for i := range n {
+ walkBeforeAfter(&n[i], before, after)
+ }
+ case []ast.Stmt:
+ for i := range n {
+ walkBeforeAfter(&n[i], before, after)
+ }
+ case []ast.Spec:
+ for i := range n {
+ walkBeforeAfter(&n[i], before, after)
+ }
+ }
+ after(x)
+}
+
+// imports returns true if f imports path.
+func imports(f *ast.File, path string) bool {
+ return importSpec(f, path) != nil
+}
+
+// importSpec returns the import spec if f imports path,
+// or nil otherwise.
+func importSpec(f *ast.File, path string) *ast.ImportSpec {
+ for _, s := range f.Imports {
+ if importPath(s) == path {
+ return s
+ }
+ }
+ return nil
+}
+
+// importPath returns the unquoted import path of s,
+// or "" if the path is not properly quoted.
+func importPath(s *ast.ImportSpec) string {
+ t, err := strconv.Unquote(s.Path.Value)
+ if err == nil {
+ return t
+ }
+ return ""
+}
+
+// declImports reports whether gen contains an import of path.
+func declImports(gen *ast.GenDecl, path string) bool {
+ if gen.Tok != token.IMPORT {
+ return false
+ }
+ for _, spec := range gen.Specs {
+ impspec := spec.(*ast.ImportSpec)
+ if importPath(impspec) == path {
+ return true
+ }
+ }
+ return false
+}
+
+// isPkgDot returns true if t is the expression "pkg.name"
+// where pkg is an imported identifier.
+func isPkgDot(t ast.Expr, pkg, name string) bool {
+ sel, ok := t.(*ast.SelectorExpr)
+ return ok && isTopName(sel.X, pkg) && sel.Sel.String() == name
+}
+
+// isPtrPkgDot returns true if f is the expression "*pkg.name"
+// where pkg is an imported identifier.
+func isPtrPkgDot(t ast.Expr, pkg, name string) bool {
+ ptr, ok := t.(*ast.StarExpr)
+ return ok && isPkgDot(ptr.X, pkg, name)
+}
+
+// isTopName returns true if n is a top-level unresolved identifier with the given name.
+func isTopName(n ast.Expr, name string) bool {
+ id, ok := n.(*ast.Ident)
+ return ok && id.Name == name && id.Obj == nil
+}
+
+// isName returns true if n is an identifier with the given name.
+func isName(n ast.Expr, name string) bool {
+ id, ok := n.(*ast.Ident)
+ return ok && id.String() == name
+}
+
+// isCall returns true if t is a call to pkg.name.
+func isCall(t ast.Expr, pkg, name string) bool {
+ call, ok := t.(*ast.CallExpr)
+ return ok && isPkgDot(call.Fun, pkg, name)
+}
+
+// If n is an *ast.Ident, isIdent returns it; otherwise isIdent returns nil.
+func isIdent(n interface{}) *ast.Ident {
+ id, _ := n.(*ast.Ident)
+ return id
+}
+
+// refersTo returns true if n is a reference to the same object as x.
+func refersTo(n ast.Node, x *ast.Ident) bool {
+ id, ok := n.(*ast.Ident)
+ // The test of id.Name == x.Name handles top-level unresolved
+ // identifiers, which all have Obj == nil.
+ return ok && id.Obj == x.Obj && id.Name == x.Name
+}
+
+// isBlank returns true if n is the blank identifier.
+func isBlank(n ast.Expr) bool {
+ return isName(n, "_")
+}
+
+// isEmptyString returns true if n is an empty string literal.
+func isEmptyString(n ast.Expr) bool {
+ lit, ok := n.(*ast.BasicLit)
+ return ok && lit.Kind == token.STRING && len(lit.Value) == 2
+}
+
+func warn(pos token.Pos, msg string, args ...interface{}) {
+ if pos.IsValid() {
+ msg = "%s: " + msg
+ arg1 := []interface{}{fset.Position(pos).String()}
+ args = append(arg1, args...)
+ }
+ fmt.Fprintf(os.Stderr, msg+"\n", args...)
+}
+
+// countUses returns the number of uses of the identifier x in scope.
+func countUses(x *ast.Ident, scope []ast.Stmt) int {
+ count := 0
+ ff := func(n interface{}) {
+ if n, ok := n.(ast.Node); ok && refersTo(n, x) {
+ count++
+ }
+ }
+ for _, n := range scope {
+ walk(n, ff)
+ }
+ return count
+}
+
+// rewriteUses replaces all uses of the identifier x and !x in scope
+// with f(x.Pos()) and fnot(x.Pos()).
+func rewriteUses(x *ast.Ident, f, fnot func(token.Pos) ast.Expr, scope []ast.Stmt) {
+ var lastF ast.Expr
+ ff := func(n interface{}) {
+ ptr, ok := n.(*ast.Expr)
+ if !ok {
+ return
+ }
+ nn := *ptr
+
+ // The child node was just walked and possibly replaced.
+ // If it was replaced and this is a negation, replace with fnot(p).
+ not, ok := nn.(*ast.UnaryExpr)
+ if ok && not.Op == token.NOT && not.X == lastF {
+ *ptr = fnot(nn.Pos())
+ return
+ }
+ if refersTo(nn, x) {
+ lastF = f(nn.Pos())
+ *ptr = lastF
+ }
+ }
+ for _, n := range scope {
+ walk(n, ff)
+ }
+}
+
+// assignsTo returns true if any of the code in scope assigns to or takes the address of x.
+func assignsTo(x *ast.Ident, scope []ast.Stmt) bool {
+ assigned := false
+ ff := func(n interface{}) {
+ if assigned {
+ return
+ }
+ switch n := n.(type) {
+ case *ast.UnaryExpr:
+ // use of &x
+ if n.Op == token.AND && refersTo(n.X, x) {
+ assigned = true
+ return
+ }
+ case *ast.AssignStmt:
+ for _, l := range n.Lhs {
+ if refersTo(l, x) {
+ assigned = true
+ return
+ }
+ }
+ }
+ }
+ for _, n := range scope {
+ if assigned {
+ break
+ }
+ walk(n, ff)
+ }
+ return assigned
+}
+
+// newPkgDot returns an ast.Expr referring to "pkg.name" at position pos.
+func newPkgDot(pos token.Pos, pkg, name string) ast.Expr {
+ return &ast.SelectorExpr{
+ X: &ast.Ident{
+ NamePos: pos,
+ Name: pkg,
+ },
+ Sel: &ast.Ident{
+ NamePos: pos,
+ Name: name,
+ },
+ }
+}
+
+// renameTop renames all references to the top-level name old.
+// It returns true if it makes any changes.
+func renameTop(f *ast.File, old, new string) bool {
+ var fixed bool
+
+ // Rename any conflicting imports
+ // (assuming package name is last element of path).
+ for _, s := range f.Imports {
+ if s.Name != nil {
+ if s.Name.Name == old {
+ s.Name.Name = new
+ fixed = true
+ }
+ } else {
+ _, thisName := path.Split(importPath(s))
+ if thisName == old {
+ s.Name = ast.NewIdent(new)
+ fixed = true
+ }
+ }
+ }
+
+ // Rename any top-level declarations.
+ for _, d := range f.Decls {
+ switch d := d.(type) {
+ case *ast.FuncDecl:
+ if d.Recv == nil && d.Name.Name == old {
+ d.Name.Name = new
+ d.Name.Obj.Name = new
+ fixed = true
+ }
+ case *ast.GenDecl:
+ for _, s := range d.Specs {
+ switch s := s.(type) {
+ case *ast.TypeSpec:
+ if s.Name.Name == old {
+ s.Name.Name = new
+ s.Name.Obj.Name = new
+ fixed = true
+ }
+ case *ast.ValueSpec:
+ for _, n := range s.Names {
+ if n.Name == old {
+ n.Name = new
+ n.Obj.Name = new
+ fixed = true
+ }
+ }
+ }
+ }
+ }
+ }
+
+ // Rename top-level old to new, both unresolved names
+ // (probably defined in another file) and names that resolve
+ // to a declaration we renamed.
+ walk(f, func(n interface{}) {
+ id, ok := n.(*ast.Ident)
+ if ok && isTopName(id, old) {
+ id.Name = new
+ fixed = true
+ }
+ if ok && id.Obj != nil && id.Name == old && id.Obj.Name == new {
+ id.Name = id.Obj.Name
+ fixed = true
+ }
+ })
+
+ return fixed
+}
+
+// matchLen returns the length of the longest prefix shared by x and y.
+func matchLen(x, y string) int {
+ i := 0
+ for i < len(x) && i < len(y) && x[i] == y[i] {
+ i++
+ }
+ return i
+}
+
+// addImport adds the import path to the file f, if absent.
+func addImport(f *ast.File, ipath string) (added bool) {
+ if imports(f, ipath) {
+ return false
+ }
+
+ // Determine name of import.
+ // Assume added imports follow convention of using last element.
+ _, name := path.Split(ipath)
+
+ // Rename any conflicting top-level references from name to name_.
+ renameTop(f, name, name+"_")
+
+ newImport := &ast.ImportSpec{
+ Path: &ast.BasicLit{
+ Kind: token.STRING,
+ Value: strconv.Quote(ipath),
+ },
+ }
+
+ // Find an import decl to add to.
+ var (
+ bestMatch = -1
+ lastImport = -1
+ impDecl *ast.GenDecl
+ impIndex = -1
+ )
+ for i, decl := range f.Decls {
+ gen, ok := decl.(*ast.GenDecl)
+ if ok && gen.Tok == token.IMPORT {
+ lastImport = i
+ // Do not add to import "C", to avoid disrupting the
+ // association with its doc comment, breaking cgo.
+ if declImports(gen, "C") {
+ continue
+ }
+
+ // Compute longest shared prefix with imports in this block.
+ for j, spec := range gen.Specs {
+ impspec := spec.(*ast.ImportSpec)
+ n := matchLen(importPath(impspec), ipath)
+ if n > bestMatch {
+ bestMatch = n
+ impDecl = gen
+ impIndex = j
+ }
+ }
+ }
+ }
+
+ // If no import decl found, add one after the last import.
+ if impDecl == nil {
+ impDecl = &ast.GenDecl{
+ Tok: token.IMPORT,
+ }
+ f.Decls = append(f.Decls, nil)
+ copy(f.Decls[lastImport+2:], f.Decls[lastImport+1:])
+ f.Decls[lastImport+1] = impDecl
+ }
+
+ // Ensure the import decl has parentheses, if needed.
+ if len(impDecl.Specs) > 0 && !impDecl.Lparen.IsValid() {
+ impDecl.Lparen = impDecl.Pos()
+ }
+
+ insertAt := impIndex + 1
+ if insertAt == 0 {
+ insertAt = len(impDecl.Specs)
+ }
+ impDecl.Specs = append(impDecl.Specs, nil)
+ copy(impDecl.Specs[insertAt+1:], impDecl.Specs[insertAt:])
+ impDecl.Specs[insertAt] = newImport
+ if insertAt > 0 {
+ // Assign same position as the previous import,
+ // so that the sorter sees it as being in the same block.
+ prev := impDecl.Specs[insertAt-1]
+ newImport.Path.ValuePos = prev.Pos()
+ newImport.EndPos = prev.Pos()
+ }
+
+ f.Imports = append(f.Imports, newImport)
+ return true
+}
+
+// deleteImport deletes the import path from the file f, if present.
+func deleteImport(f *ast.File, path string) (deleted bool) {
+ oldImport := importSpec(f, path)
+
+ // Find the import node that imports path, if any.
+ for i, decl := range f.Decls {
+ gen, ok := decl.(*ast.GenDecl)
+ if !ok || gen.Tok != token.IMPORT {
+ continue
+ }
+ for j, spec := range gen.Specs {
+ impspec := spec.(*ast.ImportSpec)
+ if oldImport != impspec {
+ continue
+ }
+
+ // We found an import spec that imports path.
+ // Delete it.
+ deleted = true
+ copy(gen.Specs[j:], gen.Specs[j+1:])
+ gen.Specs = gen.Specs[:len(gen.Specs)-1]
+
+ // If this was the last import spec in this decl,
+ // delete the decl, too.
+ if len(gen.Specs) == 0 {
+ copy(f.Decls[i:], f.Decls[i+1:])
+ f.Decls = f.Decls[:len(f.Decls)-1]
+ } else if len(gen.Specs) == 1 {
+ gen.Lparen = token.NoPos // drop parens
+ }
+ if j > 0 {
+ // We deleted an entry but now there will be
+ // a blank line-sized hole where the import was.
+ // Close the hole by making the previous
+ // import appear to "end" where this one did.
+ gen.Specs[j-1].(*ast.ImportSpec).EndPos = impspec.End()
+ }
+ break
+ }
+ }
+
+ // Delete it from f.Imports.
+ for i, imp := range f.Imports {
+ if imp == oldImport {
+ copy(f.Imports[i:], f.Imports[i+1:])
+ f.Imports = f.Imports[:len(f.Imports)-1]
+ break
+ }
+ }
+
+ return
+}
+
+// rewriteImport rewrites any import of path oldPath to path newPath.
+func rewriteImport(f *ast.File, oldPath, newPath string) (rewrote bool) {
+ for _, imp := range f.Imports {
+ if importPath(imp) == oldPath {
+ rewrote = true
+ // record old End, because the default is to compute
+ // it using the length of imp.Path.Value.
+ imp.EndPos = imp.End()
+ imp.Path.Value = strconv.Quote(newPath)
+ }
+ }
+ return
+}
+
+func usesImport(f *ast.File, path string) (used bool) {
+ spec := importSpec(f, path)
+ if spec == nil {
+ return
+ }
+
+ name := spec.Name.String()
+ switch name {
+ case "<nil>":
+ // If the package name is not explicitly specified,
+ // make an educated guess. This is not guaranteed to be correct.
+ lastSlash := strings.LastIndex(path, "/")
+ if lastSlash == -1 {
+ name = path
+ } else {
+ name = path[lastSlash+1:]
+ }
+ case "_", ".":
+ // Not sure if this import is used - err on the side of caution.
+ return true
+ }
+
+ walk(f, func(n interface{}) {
+ sel, ok := n.(*ast.SelectorExpr)
+ if ok && isTopName(sel.X, name) {
+ used = true
+ }
+ })
+
+ return
+}
+
+func expr(s string) ast.Expr {
+ x, err := parser.ParseExpr(s)
+ if err != nil {
+ panic("parsing " + s + ": " + err.Error())
+ }
+ // Remove position information to avoid spurious newlines.
+ killPos(reflect.ValueOf(x))
+ return x
+}
+
+var posType = reflect.TypeOf(token.Pos(0))
+
+func killPos(v reflect.Value) {
+ switch v.Kind() {
+ case reflect.Ptr, reflect.Interface:
+ if !v.IsNil() {
+ killPos(v.Elem())
+ }
+ case reflect.Slice:
+ n := v.Len()
+ for i := 0; i < n; i++ {
+ killPos(v.Index(i))
+ }
+ case reflect.Struct:
+ n := v.NumField()
+ for i := 0; i < n; i++ {
+ f := v.Field(i)
+ if f.Type() == posType {
+ f.SetInt(0)
+ continue
+ }
+ killPos(f)
+ }
+ }
+}
+
+// A Rename describes a single renaming.
+type rename struct {
+ OldImport string // only apply rename if this import is present
+ NewImport string // add this import during rewrite
+ Old string // old name: p.T or *p.T
+ New string // new name: p.T or *p.T
+}
+
+func renameFix(tab []rename) func(*ast.File) bool {
+ return func(f *ast.File) bool {
+ return renameFixTab(f, tab)
+ }
+}
+
+func parseName(s string) (ptr bool, pkg, nam string) {
+ i := strings.Index(s, ".")
+ if i < 0 {
+ panic("parseName: invalid name " + s)
+ }
+ if strings.HasPrefix(s, "*") {
+ ptr = true
+ s = s[1:]
+ i--
+ }
+ pkg = s[:i]
+ nam = s[i+1:]
+ return
+}
+
+func renameFixTab(f *ast.File, tab []rename) bool {
+ fixed := false
+ added := map[string]bool{}
+ check := map[string]bool{}
+ for _, t := range tab {
+ if !imports(f, t.OldImport) {
+ continue
+ }
+ optr, opkg, onam := parseName(t.Old)
+ walk(f, func(n interface{}) {
+ np, ok := n.(*ast.Expr)
+ if !ok {
+ return
+ }
+ x := *np
+ if optr {
+ p, ok := x.(*ast.StarExpr)
+ if !ok {
+ return
+ }
+ x = p.X
+ }
+ if !isPkgDot(x, opkg, onam) {
+ return
+ }
+ if t.NewImport != "" && !added[t.NewImport] {
+ addImport(f, t.NewImport)
+ added[t.NewImport] = true
+ }
+ *np = expr(t.New)
+ check[t.OldImport] = true
+ fixed = true
+ })
+ }
+
+ for ipath := range check {
+ if !usesImport(f, ipath) {
+ deleteImport(f, ipath)
+ }
+ }
+ return fixed
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-03 18:49:49 +0000