Avoid creation of irrelevant temporary files on Windows

Signed-off-by: Simon Ferquel <simon.ferquel@docker.com>

util/binfmt_misc/check.go

@@ -1,42 +0,0 @@
-package binfmt_misc
-
-import (
-	"bytes"
-	"compress/gzip"
-	"io"
-	"io/ioutil"
-	"os"
-	"os/exec"
-	"path/filepath"
-)
-
-func check(bin string) error {
-	tmpdir, err := ioutil.TempDir("", "qemu-check")
-	if err != nil {
-		return err
-	}
-	defer os.RemoveAll(tmpdir)
-	pp := filepath.Join(tmpdir, "check")
-
-	r, err := gzip.NewReader(bytes.NewReader([]byte(bin)))
-	if err != nil {
-		return err
-	}
-	defer r.Close()
-
-	f, err := os.OpenFile(pp, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0700)
-	if err != nil {
-		return err
-	}
-
-	if _, err := io.Copy(f, r); err != nil {
-		f.Close()
-		return err
-	}
-	f.Close()
-
-	cmd := exec.Command("/check")
-	withChroot(cmd, tmpdir)
-	err = cmd.Run()
-	return err
-}

util/binfmt_misc/check_unix.go

@@ -3,7 +3,13 @@
 package binfmt_misc
 
 import (
+	"bytes"
+	"compress/gzip"
+	"io"
+	"io/ioutil"
+	"os"
 	"os/exec"
+	"path/filepath"
 	"syscall"
 )
 
@@ -12,3 +18,34 @@ func withChroot(cmd *exec.Cmd, dir string) {
 		Chroot: dir,
 	}
 }
+
+func check(bin string) error {
+	tmpdir, err := ioutil.TempDir("", "qemu-check")
+	if err != nil {
+		return err
+	}
+	defer os.RemoveAll(tmpdir)
+	pp := filepath.Join(tmpdir, "check")
+
+	r, err := gzip.NewReader(bytes.NewReader([]byte(bin)))
+	if err != nil {
+		return err
+	}
+	defer r.Close()
+
+	f, err := os.OpenFile(pp, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0700)
+	if err != nil {
+		return err
+	}
+
+	if _, err := io.Copy(f, r); err != nil {
+		f.Close()
+		return err
+	}
+	f.Close()
+
+	cmd := exec.Command("/check")
+	withChroot(cmd, tmpdir)
+	err = cmd.Run()
+	return err
+}

util/binfmt_misc/check_windows.go

@@ -3,8 +3,13 @@
 package binfmt_misc
 
 import (
+	"errors"
 	"os/exec"
 )
 
 func withChroot(cmd *exec.Cmd, dir string) {
 }
+
+func check(bin string) error {
+	return errors.New("binfmt is not supported on Windows")
+}