1 files changed, 49 insertions, 0 deletions
diff --git a/src/cmd/oldlink/internal/ld/outbuf_windows.go b/src/cmd/oldlink/internal/ld/outbuf_windows.go
new file mode 100644
index 0000000000..1cb05c301f
--- /dev/null
+++ b/src/cmd/oldlink/internal/ld/outbuf_windows.go
@@ -0,0 +1,49 @@
+// 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.
+
+package ld
+
+import (
+	"reflect"
+	"syscall"
+	"unsafe"
+)
+
+func (out *OutBuf) Mmap(filesize uint64) error {
+	err := out.f.Truncate(int64(filesize))
+	if err != nil {
+		Exitf("resize output file failed: %v", err)
+	}
+
+	low, high := uint32(filesize), uint32(filesize>>32)
+	fmap, err := syscall.CreateFileMapping(syscall.Handle(out.f.Fd()), nil, syscall.PAGE_READONLY, high, low, nil)
+	if err != nil {
+		return err
+	}
+	defer syscall.CloseHandle(fmap)
+
+	ptr, err := syscall.MapViewOfFile(fmap, syscall.FILE_MAP_READ|syscall.FILE_MAP_WRITE, 0, 0, uintptr(filesize))
+	if err != nil {
+		return err
+	}
+	*(*reflect.SliceHeader)(unsafe.Pointer(&out.buf)) = reflect.SliceHeader{Data: ptr, Len: int(filesize), Cap: int(filesize)}
+	return nil
+}
+
+func (out *OutBuf) Munmap() {
+	if out.buf == nil {
+		return
+	}
+	err := syscall.UnmapViewOfFile(uintptr(unsafe.Pointer(&out.buf[0])))
+	if err != nil {
+		Exitf("UnmapViewOfFile failed: %v", err)
+	}
+}
+
+func (out *OutBuf) Msync() error {
+	if out.buf == nil {
+		return nil
+	}
+	return syscall.FlushViewOfFile(uintptr(unsafe.Pointer(&out.buf[0])), 0)
+}