build: force all Windows batch files to CRLF

Batch files should use CRLF endings. LF endings mostly
work but in some situations they cause random errors like
goto commands failing for mysterious reasons. See
golang.org/issue/37791 for more information.

Next CL triggered one of such bug (a label was not being
recognized), so prepare for it by converting to CRLF.

This CL also touches all existing batch files to force git
to update the line endings (unfortunately, changing
.gitattributes only has effect next time the file is checked
out or modified).

Fixes #37791
Updates #9281

Change-Id: I6f9a114351cb7ac9881914400aa210c930eb8cc1
Reviewed-on: https://go-review.googlesource.com/c/go/+/96495
Run-TryBot: Giovanni Bajo <rasky@develer.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

7 files changed, 40 insertions, 1 deletions

diff --git a/.gitattributes b/.gitattributes
index 07953cae39..bcea0290f4 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -8,3 +8,9 @@
 # See golang.org/issue/9281
 
 * -text
+
+# The only exception is Windows files that must absolutely be CRLF or
+# might not work. Batch files are known to have multiple bugs when run
+# with LF endings. See golang.org/issue/37791 for more information.
+
+*.bat text eol=crlf
diff --git a/src/all.bat b/src/all.bat
index 0647a715ba..8bbd6b1b5d 100644
--- a/src/all.bat
+++ b/src/all.bat
@@ -1,6 +1,7 @@
 :: 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.
+
 @echo off
 
 setlocal
diff --git a/src/clean.bat b/src/clean.bat
index 3cc6a689bc..0954dcd67f 100644
--- a/src/clean.bat
+++ b/src/clean.bat
@@ -1,6 +1,7 @@
 :: 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.
+
 @echo off
 
 setlocal
diff --git a/src/make.bat b/src/make.bat
index d18cd87d48..5dbde85564 100644
--- a/src/make.bat
+++ b/src/make.bat
@@ -132,3 +132,4 @@ set GOBUILDFAIL=1
 if x%GOBUILDEXIT%==x1 exit %GOBUILDFAIL%
 
 :end
+
diff --git a/src/race.bat b/src/race.bat
index e1c3fbf5d9..d26f3180a3 100644
--- a/src/race.bat
+++ b/src/race.bat
@@ -49,4 +49,3 @@ echo All tests passed.
 
 :end
 if x%GOBUILDEXIT%==x1 exit %GOBUILDFAIL%
-
diff --git a/src/run.bat b/src/run.bat
index 123edcc35d..25ee58001e 100644
--- a/src/run.bat
+++ b/src/run.bat
@@ -1,6 +1,7 @@
 :: 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.
+
 @echo off
 
 :: Keep environment variables within this script
diff --git a/test/winbatch.go b/test/winbatch.go
new file mode 100644
index 0000000000..30e0e3c982
--- /dev/null
+++ b/test/winbatch.go
@@ -0,0 +1,30 @@
+// run
+
+// Copyright 2020 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.
+
+// Check that batch files are maintained as CRLF files (consistent behaviour
+// on all operating systems). See https://github.com/golang/go/issues/37791
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"runtime"
+)
+
+func main() {
+	batches, _ := filepath.Glob(runtime.GOROOT() + "/src/*.bat")
+	for _, bat := range batches {
+		body, _ := ioutil.ReadFile(bat)
+		if !bytes.Contains(body, []byte("\r\n")) {
+			fmt.Printf("Windows batch file %s does not contain CRLF line termination.\nTry running git checkout src/*.bat to fix this.\n", bat)
+			os.Exit(1)
+		}
+	}
+}