Adding upstream version 1.21.8.upstream/1.21.8

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

4 files changed, 129 insertions, 0 deletions

diff --git a/src/cmd/go/internal/mmap/mmap.go b/src/cmd/go/internal/mmap/mmap.go
new file mode 100644
index 0000000..0cad9ca
--- /dev/null
+++ b/src/cmd/go/internal/mmap/mmap.go
@@ -0,0 +1,31 @@
+// 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.
+
+// This package is a lightly modified version of the mmap code
+// in github.com/google/codesearch/index.
+
+// The mmap package provides an abstraction for memory mapping files
+// on different platforms.
+package mmap
+
+import (
+	"os"
+)
+
+// Data is mmap'ed read-only data from a file.
+// The backing file is never closed, so Data
+// remains valid for the lifetime of the process.
+type Data struct {
+	f    *os.File
+	Data []byte
+}
+
+// Mmap maps the given file into memory.
+func Mmap(file string) (Data, error) {
+	f, err := os.Open(file)
+	if err != nil {
+		return Data{}, err
+	}
+	return mmapFile(f)
+}
diff --git a/src/cmd/go/internal/mmap/mmap_other.go b/src/cmd/go/internal/mmap/mmap_other.go
new file mode 100644
index 0000000..22e9395
--- /dev/null
+++ b/src/cmd/go/internal/mmap/mmap_other.go
@@ -0,0 +1,21 @@
+// Copyright 2022 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) || wasip1 || plan9
+
+package mmap
+
+import (
+	"io"
+	"os"
+)
+
+// mmapFile on other systems doesn't mmap the file. It just reads everything.
+func mmapFile(f *os.File) (Data, error) {
+	b, err := io.ReadAll(f)
+	if err != nil {
+		return Data{}, err
+	}
+	return Data{f, b}, nil
+}
diff --git a/src/cmd/go/internal/mmap/mmap_unix.go b/src/cmd/go/internal/mmap/mmap_unix.go
new file mode 100644
index 0000000..53bcbb9
--- /dev/null
+++ b/src/cmd/go/internal/mmap/mmap_unix.go
@@ -0,0 +1,36 @@
+// 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.
+
+//go:build unix
+
+package mmap
+
+import (
+	"fmt"
+	"io/fs"
+	"os"
+	"syscall"
+)
+
+func mmapFile(f *os.File) (Data, error) {
+	st, err := f.Stat()
+	if err != nil {
+		return Data{}, err
+	}
+	size := st.Size()
+	pagesize := int64(os.Getpagesize())
+	if int64(int(size+(pagesize-1))) != size+(pagesize-1) {
+		return Data{}, fmt.Errorf("%s: too large for mmap", f.Name())
+	}
+	n := int(size)
+	if n == 0 {
+		return Data{f, nil}, nil
+	}
+	mmapLength := int(((size + pagesize - 1) / pagesize) * pagesize) // round up to page size
+	data, err := syscall.Mmap(int(f.Fd()), 0, mmapLength, syscall.PROT_READ, syscall.MAP_SHARED)
+	if err != nil {
+		return Data{}, &fs.PathError{Op: "mmap", Path: f.Name(), Err: err}
+	}
+	return Data{f, data[:n]}, nil
+}
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
+}