1 files changed, 28 insertions, 0 deletions
diff --git a/src/cmd/go/internal/modload/stat_openfile.go b/src/cmd/go/internal/modload/stat_openfile.go
new file mode 100644
index 0000000..5773073
--- /dev/null
+++ b/src/cmd/go/internal/modload/stat_openfile.go
@@ -0,0 +1,28 @@
+// Copyright 2019 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.
+
+//go:build (js && wasm) || plan9
+
+// On plan9, per http://9p.io/magic/man2html/2/access: “Since file permissions
+// are checked by the server and group information is not known to the client,
+// access must open the file to check permissions.”
+//
+// js,wasm is similar, in that it does not define syscall.Access.
+
+package modload
+
+import (
+	"io/fs"
+	"os"
+)
+
+// hasWritePerm reports whether the current user has permission to write to the
+// file with the given info.
+func hasWritePerm(path string, _ fs.FileInfo) bool {
+	if f, err := os.OpenFile(path, os.O_WRONLY, 0); err == nil {
+		f.Close()
+		return true
+	}
+	return false
+}