From da8f037b57241b0b84fab9d4c9e69b53e7118850 Mon Sep 17 00:00:00 2001 From: Nigel Tao Date: Wed, 15 Feb 2012 14:41:47 +1100 Subject: [PATCH] fix: add fix for bufio, gzip, zlib NewWriterXxx changes. Fixes #2979. R=rsc, r CC=golang-dev https://golang.org/cl/5664046 --- doc/go1.html | 22 +++++---- doc/go1.tmpl | 22 +++++---- src/cmd/fix/newwriter.go | 90 +++++++++++++++++++++++++++++++++++ src/cmd/fix/newwriter_test.go | 83 ++++++++++++++++++++++++++++++++ 4 files changed, 199 insertions(+), 18 deletions(-) create mode 100644 src/cmd/fix/newwriter.go create mode 100644 src/cmd/fix/newwriter_test.go diff --git a/doc/go1.html b/doc/go1.html index 9b62d1a1ad..a2cd0456a6 100644 --- a/doc/go1.html +++ b/doc/go1.html @@ -578,7 +578,7 @@ If they are installed, they now reside in $GOROOT/bin/tool. Updating: Code that uses packages in exp will need to be updated by hand, or else compiled from an installation that has exp available. -The go fix tool or the compiler will complain about such uses. +The go fix tool or the compiler will complain about such uses.

The package tree old

@@ -603,7 +603,7 @@ The packages in their new locations are: Updating: Code that uses packages now in old will need to be updated by hand, or else compiled from an installation that has old available. -The go fix tool will warn about such uses. +The go fix tool will warn about such uses.

Deleted packages

@@ -863,8 +863,8 @@ longer has a Write method. Its presence was a mistake.

-Updating: What little code is affected will be caught by the compiler -and must be updated by hand. Such code is almost certainly incorrect. +Updating: +What little code is affected will be caught by the compiler and must be updated by hand.

The bufio package

@@ -879,7 +879,8 @@ If the argument size is too small or invalid, it is adjusted.

Updating: -What little code is affected will be caught by the compiler and must be updated by hand. +Running go fix will update calls that assign the error to _. +Calls that aren't fixed will be caught by the compiler and must be updated by hand.

The compress/flate, compress/gzip and compress/zlib packages

@@ -898,7 +899,8 @@ to Writer and Reader. Package flate's

Updating -What little code is affected will be caught by the compiler and must be updated by hand. +Running go fix will update old names and calls that assign the error to _. +Calls that aren't fixed will be caught by the compiler and must be updated by hand.

The crypto/aes and crypto/des packages

@@ -1425,8 +1427,10 @@ now takes a uintptr fd, instead of an int. The Fd method on files now also returns a uintptr.

-

Updating: Code will fail to compile and must be updated -by hand.

+

+Updating: +What little code is affected will be caught by the compiler and must be updated by hand. +

The os.FileInfo type

@@ -1669,7 +1673,7 @@ Running go fix will update almost all code affected by the change.
§ Atoi persists but Atoui and Atof32 do not, so they may require -a cast that must be added by hand; the go fix tool will warn about it. +a cast that must be added by hand; the go fix tool will warn about it.

diff --git a/doc/go1.tmpl b/doc/go1.tmpl index efe43bc3bf..90bc9fc7f6 100644 --- a/doc/go1.tmpl +++ b/doc/go1.tmpl @@ -502,7 +502,7 @@ If they are installed, they now reside in $GOROOT/bin/tool. Updating: Code that uses packages in exp will need to be updated by hand, or else compiled from an installation that has exp available. -The go fix tool or the compiler will complain about such uses. +The go fix tool or the compiler will complain about such uses.

The package tree old

@@ -527,7 +527,7 @@ The packages in their new locations are: Updating: Code that uses packages now in old will need to be updated by hand, or else compiled from an installation that has old available. -The go fix tool will warn about such uses. +The go fix tool will warn about such uses.

Deleted packages

@@ -767,8 +767,8 @@ longer has a Write method. Its presence was a mistake.

-Updating: What little code is affected will be caught by the compiler -and must be updated by hand. Such code is almost certainly incorrect. +Updating: +What little code is affected will be caught by the compiler and must be updated by hand.

The bufio package

@@ -783,7 +783,8 @@ If the argument size is too small or invalid, it is adjusted.

Updating: -What little code is affected will be caught by the compiler and must be updated by hand. +Running go fix will update calls that assign the error to _. +Calls that aren't fixed will be caught by the compiler and must be updated by hand.

The compress/flate, compress/gzip and compress/zlib packages

@@ -802,7 +803,8 @@ to Writer and Reader. Package flate's

Updating -What little code is affected will be caught by the compiler and must be updated by hand. +Running go fix will update old names and calls that assign the error to _. +Calls that aren't fixed will be caught by the compiler and must be updated by hand.

The crypto/aes and crypto/des packages

@@ -1328,8 +1330,10 @@ now takes a uintptr fd, instead of an int. The Fd method on files now also returns a uintptr.

-

Updating: Code will fail to compile and must be updated -by hand.

+

+Updating: +What little code is affected will be caught by the compiler and must be updated by hand. +

The os.FileInfo type

@@ -1572,7 +1576,7 @@ Running go fix will update almost all code affected by the change.
§ Atoi persists but Atoui and Atof32 do not, so they may require -a cast that must be added by hand; the go fix tool will warn about it. +a cast that must be added by hand; the go fix tool will warn about it.

diff --git a/src/cmd/fix/newwriter.go b/src/cmd/fix/newwriter.go new file mode 100644 index 0000000000..4befe24fb6 --- /dev/null +++ b/src/cmd/fix/newwriter.go @@ -0,0 +1,90 @@ +// 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 + +import ( + "go/ast" +) + +func init() { + register(newWriterFix) +} + +var newWriterFix = fix{ + "newWriter", + "2012-02-14", + newWriter, + `Adapt bufio, gzip and zlib NewWriterXxx calls for whether they return errors. + +Also rename gzip.Compressor and gzip.Decompressor to gzip.Writer and gzip.Reader. + +http://codereview.appspot.com/5639057 and +http://codereview.appspot.com/5642054 +`, +} + +func newWriter(f *ast.File) bool { + if !imports(f, "bufio") && !imports(f, "compress/gzip") && !imports(f, "compress/zlib") { + return false + } + + fixed := false + walk(f, func(n interface{}) { + switch n := n.(type) { + case *ast.SelectorExpr: + if isTopName(n.X, "gzip") { + switch n.Sel.String() { + case "Compressor": + n.Sel = &ast.Ident{Name: "Writer"} + fixed = true + case "Decompressor": + n.Sel = &ast.Ident{Name: "Reader"} + fixed = true + } + } else if isTopName(n.X, "zlib") { + if n.Sel.String() == "NewWriterDict" { + n.Sel = &ast.Ident{Name: "NewWriterLevelDict"} + fixed = true + } + } + + case *ast.AssignStmt: + // Drop the ", _" in assignments of the form: + // w0, _ = gzip.NewWriter(w1) + if len(n.Lhs) != 2 || len(n.Rhs) != 1 { + return + } + i, ok := n.Lhs[1].(*ast.Ident) + if !ok { + return + } + if i.String() != "_" { + return + } + c, ok := n.Rhs[0].(*ast.CallExpr) + if !ok { + return + } + s, ok := c.Fun.(*ast.SelectorExpr) + if !ok { + return + } + sel := s.Sel.String() + switch { + case isTopName(s.X, "bufio") && (sel == "NewReaderSize" || sel == "NewWriterSize"): + // No-op. + case isTopName(s.X, "gzip") && sel == "NewWriter": + // No-op. + case isTopName(s.X, "zlib") && sel == "NewWriter": + // No-op. + default: + return + } + n.Lhs = n.Lhs[:1] + fixed = true + } + }) + return fixed +} diff --git a/src/cmd/fix/newwriter_test.go b/src/cmd/fix/newwriter_test.go new file mode 100644 index 0000000000..1f59628a0d --- /dev/null +++ b/src/cmd/fix/newwriter_test.go @@ -0,0 +1,83 @@ +// 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(newWriterTests, newWriter) +} + +var newWriterTests = []testCase{ + { + Name: "newWriter.0", + In: `package main + +import ( + "bufio" + "compress/gzip" + "compress/zlib" + "io" + + "foo" +) + +func f() *gzip.Compressor { + var ( + _ gzip.Compressor + _ *gzip.Decompressor + _ struct { + W *gzip.Compressor + R gzip.Decompressor + } + ) + + var w io.Writer + br := bufio.NewReader(nil) + br, _ = bufio.NewReaderSize(nil, 256) + bw, err := bufio.NewWriterSize(w, 256) // Unfixable, as it declares an err variable. + bw, _ = bufio.NewWriterSize(w, 256) + fw, _ := foo.NewWriter(w) + gw, _ := gzip.NewWriter(w) + gw, _ = gzip.NewWriter(w) + zw, _ := zlib.NewWriter(w) + _ = zlib.NewWriterDict(zw, 0, nil) + return gw +} +`, + Out: `package main + +import ( + "bufio" + "compress/gzip" + "compress/zlib" + "io" + + "foo" +) + +func f() *gzip.Writer { + var ( + _ gzip.Writer + _ *gzip.Reader + _ struct { + W *gzip.Writer + R gzip.Reader + } + ) + + var w io.Writer + br := bufio.NewReader(nil) + br = bufio.NewReaderSize(nil, 256) + bw, err := bufio.NewWriterSize(w, 256) // Unfixable, as it declares an err variable. + bw = bufio.NewWriterSize(w, 256) + fw, _ := foo.NewWriter(w) + gw := gzip.NewWriter(w) + gw = gzip.NewWriter(w) + zw := zlib.NewWriter(w) + _ = zlib.NewWriterLevelDict(zw, 0, nil) + return gw +} +`, + }, +}