gofix: netdial

R=adg
CC=golang-dev
https://golang.org/cl/4278053

diff --git a/src/cmd/gofix/Makefile b/src/cmd/gofix/Makefile
index 4143e0cbe116156d0853b07aa92e4db8f68c791e..f60b503d4b625d318deaa2855af6047ace3fa1a6 100644 (file)
--- a/src/cmd/gofix/Makefile
+++ b/src/cmd/gofix/Makefile
@@ -7,6 +7,7 @@ include ../../Make.inc
 TARG=gofix
 GOFILES=\
        fix.go\
+       netdial.go\
        main.go\
        httpserver.go\
        procattr.go\

diff --git a/src/cmd/gofix/fix.go b/src/cmd/gofix/fix.go
index c7f461168a9e9038d5c7922606effa13c91d4f82..93cbc94e21866904c29ab83ea3efde58abb1c297 100644 (file)
--- a/src/cmd/gofix/fix.go
+++ b/src/cmd/gofix/fix.go
@@ -242,7 +242,7 @@ func isPkgDot(t ast.Expr, pkg, name string) bool {
        if !ok {
                return false
        }
-       return isName(sel.X, pkg) && sel.Sel.String() == name
+       return isTopName(sel.X, pkg) && sel.Sel.String() == name
 }
 
 func isPtrPkgDot(t ast.Expr, pkg, name string) bool {
@@ -253,6 +253,14 @@ func isPtrPkgDot(t ast.Expr, pkg, name string) bool {
        return isPkgDot(ptr.X, pkg, name)
 }
 
+func isTopName(n ast.Expr, name string) bool {
+       id, ok := n.(*ast.Ident)
+       if !ok {
+               return false
+       }
+       return id.Name == name && id.Obj == nil
+}
+
 func isName(n ast.Expr, name string) bool {
        id, ok := n.(*ast.Ident)
        if !ok {
@@ -291,9 +299,10 @@ func isEmptyString(n ast.Expr) bool {
 }
 
 func warn(pos token.Pos, msg string, args ...interface{}) {
-       s := ""
        if pos.IsValid() {
-               s = fmt.Sprintf("%s: ", fset.Position(pos).String())
+               msg = "%s: " + msg
+               arg1 := []interface{}{fset.Position(pos).String()}
+               args = append(arg1, args...)
        }
-       fmt.Fprintf(os.Stderr, "%s"+msg+"\n", append([]interface{}{s}, args...))
+       fmt.Fprintf(os.Stderr, msg+"\n", args...)
 }

diff --git a/src/cmd/gofix/main.go b/src/cmd/gofix/main.go
index 9ca2ddb461cb68ef34c685adc962c5603f2737f1..e4802cdb895fa480fcee415a3ed033e04227b0ec 100644 (file)
--- a/src/cmd/gofix/main.go
+++ b/src/cmd/gofix/main.go
@@ -124,7 +124,7 @@ func processFile(filename string, useStdin bool) os.Error {
        if !fixed {
                return nil
        }
-       fmt.Fprintf(os.Stderr, "%s: %s\n", filename, buf.String()[1:])
+       fmt.Fprintf(os.Stderr, "%s: fixed %s\n", filename, buf.String()[1:])
 
        buf.Reset()
        _, err = (&printer.Config{printerMode, tabWidth}).Fprint(&buf, fset, file)

diff --git a/src/cmd/gofix/netdial.go b/src/cmd/gofix/netdial.go
new file mode 100644 (file)
index 0000000..e9196f0
--- /dev/null
+++ b/src/cmd/gofix/netdial.go
@@ -0,0 +1,114 @@
+// 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 (
+       "go/ast"
+)
+
+var netdialFix = fix{
+       "netdial",
+       netdial,
+`Adapt 3-argument calls of net.Dial to use 2-argument form.
+
+http://codereview.appspot.com/4244055
+`,
+}
+
+var tlsdialFix = fix{
+       "tlsdial",
+       tlsdial,
+`Adapt 4-argument calls of tls.Dial to use 3-argument form.
+
+http://codereview.appspot.com/4244055
+`,
+}
+
+var netlookupFix = fix{
+       "netlookup",
+       netlookup,
+`Adapt 3-result calls to net.LookupHost to use 2-result form.
+
+http://codereview.appspot.com/4244055
+`,
+}
+
+func init() {
+       register(netdialFix)
+       register(tlsdialFix)
+       register(netlookupFix)
+}
+
+func netdial(f *ast.File) bool {
+       if !imports(f, "net") {
+               return false
+       }
+
+       fixed := false
+       rewrite(f, func(n interface{}) {
+               call, ok := n.(*ast.CallExpr)
+               if !ok || !isPkgDot(call.Fun, "net", "Dial") || len(call.Args) != 3 {
+                       return
+               }
+               // net.Dial(a, "", b) -> net.Dial(a, b)
+               if !isEmptyString(call.Args[1]) {
+                       warn(call.Pos(), "call to net.Dial with non-empty second argument")
+                       return
+               }
+               call.Args[1] = call.Args[2]
+               call.Args = call.Args[:2]
+               fixed = true
+       })
+       return fixed
+}
+
+func tlsdial(f *ast.File) bool {
+       if !imports(f, "crypto/tls") {
+               return false
+       }
+
+       fixed := false
+       rewrite(f, func(n interface{}) {
+               call, ok := n.(*ast.CallExpr)
+               if !ok || !isPkgDot(call.Fun, "tls", "Dial") || len(call.Args) != 4 {
+                       return
+               }
+               // tls.Dial(a, "", b, c) -> tls.Dial(a, b, c)
+               if !isEmptyString(call.Args[1]) {
+                       warn(call.Pos(), "call to tls.Dial with non-empty second argument")
+                       return
+               }
+               call.Args[1] = call.Args[2]
+               call.Args[2] = call.Args[3]
+               call.Args = call.Args[:3]
+               fixed = true
+       })
+       return fixed
+}
+
+func netlookup(f *ast.File) bool {
+       if !imports(f, "net") {
+               return false
+       }
+
+       fixed := false
+       rewrite(f, func(n interface{}) {
+               as, ok := n.(*ast.AssignStmt)
+               if !ok || len(as.Lhs) != 3 || len(as.Rhs) != 1 {
+                       return
+               }
+               call, ok := as.Rhs[0].(*ast.CallExpr)
+               if !ok || !isPkgDot(call.Fun, "net", "LookupHost") {
+                       return
+               }
+               if !isBlank(as.Lhs[2]) {
+                       warn(as.Pos(), "call to net.LookupHost expecting cname; use net.LookupCNAME")
+                       return
+               }
+               as.Lhs = as.Lhs[:2]
+               fixed = true
+       })
+       return fixed
+}

diff --git a/src/cmd/gofix/netdial_test.go b/src/cmd/gofix/netdial_test.go
new file mode 100644 (file)
index 0000000..272aa52
--- /dev/null
+++ b/src/cmd/gofix/netdial_test.go
@@ -0,0 +1,51 @@
+package main
+
+func init() {
+       addTestCases(netdialTests)
+}
+
+var netdialTests = []testCase{
+       {
+               Name: "netdial.0",
+               In: `package main
+
+import "net"
+
+func f() {
+       c, err := net.Dial(net, "", addr)
+       c, err = net.Dial(net, "", addr)
+}
+`,
+               Out: `package main
+
+import "net"
+
+func f() {
+       c, err := net.Dial(net, addr)
+       c, err = net.Dial(net, addr)
+}
+`,
+       },
+
+       {
+               Name: "netlookup.0",
+               In: `package main
+
+import "net"
+
+func f() {
+       foo, bar, _ := net.LookupHost(host)
+       foo, bar, _ = net.LookupHost(host)
+}
+`,
+               Out: `package main
+
+import "net"
+
+func f() {
+       foo, bar := net.LookupHost(host)
+       foo, bar = net.LookupHost(host)
+}
+`,
+       },
+}