fix: add fix for crypto type change

Fixes #2905.

R=golang-dev, bradfitz, r
CC=golang-dev
https://golang.org/cl/5645088

diff --git a/src/cmd/fix/cryptotype.go b/src/cmd/fix/cryptotype.go
new file mode 100644 (file)
index 0000000..abcf771
--- /dev/null
+++ b/src/cmd/fix/cryptotype.go
@@ -0,0 +1,36 @@
+// Copyright 2012 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
+
+var cryptotypeFix = fix{
+       "cryptotype",
+       "2012-02-12",
+       renameFix(cryptotypeReplace),
+       `Rewrite uses of concrete cipher types to refer to the generic cipher.Block.
+
+http://codereview.appspot.com/5625045/
+`,
+}
+
+var cryptotypeReplace = []rename{
+       {
+               OldImport: "crypto/aes",
+               NewImport: "crypto/cipher",
+               Old:       "*aes.Cipher",
+               New:       "cipher.Block",
+       },
+       {
+               OldImport: "crypto/des",
+               NewImport: "crypto/cipher",
+               Old:       "*des.Cipher",
+               New:       "cipher.Block",
+       },
+       {
+               OldImport: "crypto/des",
+               NewImport: "crypto/cipher",
+               Old:       "*des.TripleDESCipher",
+               New:       "cipher.Block",
+       },
+}

diff --git a/src/cmd/fix/cryptotype_test.go b/src/cmd/fix/cryptotype_test.go
new file mode 100644 (file)
index 0000000..7acccee
--- /dev/null
+++ b/src/cmd/fix/cryptotype_test.go
@@ -0,0 +1,43 @@
+// Copyright 2012 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
+
+func init() {
+       addTestCases(cryptotypeTests, cryptotypeFix.f)
+}
+
+var cryptotypeTests = []testCase{
+       {
+               Name: "cryptotype.0",
+               In: `package main
+
+import (
+       "crypto/aes"
+       "crypto/des"
+)
+
+var (
+       _ *aes.Cipher
+       _ *des.Cipher
+       _ *des.TripleDESCipher
+       _ = aes.New()
+)
+`,
+               Out: `package main
+
+import (
+       "crypto/aes"
+       "crypto/cipher"
+)
+
+var (
+       _ cipher.Block
+       _ cipher.Block
+       _ cipher.Block
+       _ = aes.New()
+)
+`,
+       },
+}

diff --git a/src/cmd/fix/fix.go b/src/cmd/fix/fix.go
index 2c1be6942a6d310e1c515d00da59a8aab11f5f9c..d2067cb51ec0cb5dac85a740763e4ea6ddf91f6d 100644 (file)
--- a/src/cmd/fix/fix.go
+++ b/src/cmd/fix/fix.go
@@ -4,14 +4,6 @@
 
 package main
 
-/*
-receiver named error
-function named error
-method on error
-exiterror
-slice of named type (go/scanner)
-*/
-
 import (
        "fmt"
        "go/ast"
@@ -19,6 +11,7 @@ import (
        "go/token"
        "os"
        "path"
+       "reflect"
        "strconv"
        "strings"
 )
@@ -750,5 +743,105 @@ func expr(s string) ast.Expr {
        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
+}