Adding upstream version 1.21.8.upstream/1.21.8

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 41 insertions, 0 deletions

diff --git a/src/cmd/go/internal/mmap/mmap_windows.go b/src/cmd/go/internal/mmap/mmap_windows.go
new file mode 100644
index 0000000..1cf62fe
--- /dev/null
+++ b/src/cmd/go/internal/mmap/mmap_windows.go
@@ -0,0 +1,41 @@
+// Copyright 2011 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 mmap
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+	"unsafe"
+
+	"internal/syscall/windows"
+)
+
+func mmapFile(f *os.File) (Data, error) {
+	st, err := f.Stat()
+	if err != nil {
+		return Data{}, err
+	}
+	size := st.Size()
+	if size == 0 {
+		return Data{f, nil}, nil
+	}
+	h, err := syscall.CreateFileMapping(syscall.Handle(f.Fd()), nil, syscall.PAGE_READONLY, 0, 0, nil)
+	if err != nil {
+		return Data{}, fmt.Errorf("CreateFileMapping %s: %w", f.Name(), err)
+	}
+
+	addr, err := syscall.MapViewOfFile(h, syscall.FILE_MAP_READ, 0, 0, 0)
+	if err != nil {
+		return Data{}, fmt.Errorf("MapViewOfFile %s: %w", f.Name(), err)
+	}
+	var info windows.MemoryBasicInformation
+	err = windows.VirtualQuery(addr, &info, unsafe.Sizeof(info))
+	if err != nil {
+		return Data{}, fmt.Errorf("VirtualQuery %s: %w", f.Name(), err)
+	}
+	data := unsafe.Slice((*byte)(unsafe.Pointer(addr)), int(info.RegionSize))
+	return Data{f, data}, nil
+}