cmd/internal/osinfo: stop importing golang.org/x/sys/unix

This is the only non-vendored file that imports x/sys/unix.
Switch to fetching the information in this package.

Change-Id: I4e54c2cd8b4953066e2bee42922f35c387fb43e9
Reviewed-on: https://go-review.googlesource.com/c/go/+/623435
Auto-Submit: Ian Lance Taylor <iant@google.com>
Commit-Queue: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

src/cmd/internal/osinfo/os_solaris.go

@@ -0,0 +1,36 @@
+// Copyright 2024 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.
+
+// Supporting definitions for os_uname.go on Solaris.
+
+package osinfo
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+type utsname struct {
+	Sysname  [257]byte
+	Nodename [257]byte
+	Release  [257]byte
+	Version  [257]byte
+	Machine  [257]byte
+}
+
+//go:cgo_import_dynamic libc_uname uname "libc.so"
+//go:linkname procUname libc_uname
+
+var procUname uintptr
+
+//go:linkname rawsysvicall6 runtime.syscall_rawsysvicall6
+func rawsysvicall6(fn, nargs, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err syscall.Errno)
+
+func uname(buf *utsname) error {
+	_, _, errno := rawsysvicall6(uintptr(unsafe.Pointer(&procUname)), 1, uintptr(unsafe.Pointer(buf)), 0, 0, 0, 0, 0)
+	if errno != 0 {
+		return errno
+	}
+	return nil
+}

src/cmd/internal/osinfo/os_syscall.go

@@ -0,0 +1,17 @@
+// Copyright 2024 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 aix || linux
+
+// Supporting definitions for os_uname.go on AIX and Linux.
+
+package osinfo
+
+import "syscall"
+
+type utsname = syscall.Utsname
+
+func uname(buf *utsname) error {
+	return syscall.Uname(buf)
+}

src/cmd/internal/osinfo/os_sysctl.go

@@ -0,0 +1,41 @@
+// 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 darwin || dragonfly || freebsd || netbsd || openbsd
+
+package osinfo
+
+import (
+	"strings"
+	"syscall"
+)
+
+// Version returns the OS version name/number.
+func Version() (string, error) {
+	sysname, err := syscall.Sysctl("kern.ostype")
+	if err != nil {
+		return "", err
+	}
+	release, err := syscall.Sysctl("kern.osrelease")
+	if err != nil {
+		return "", err
+	}
+	version, err := syscall.Sysctl("kern.version")
+	if err != nil {
+		return "", err
+	}
+
+	// The version might have newlines or tabs; convert to spaces.
+	version = strings.ReplaceAll(version, "\n", " ")
+	version = strings.ReplaceAll(version, "\t", " ")
+	version = strings.TrimSpace(version)
+
+	machine, err := syscall.Sysctl("hw.machine")
+	if err != nil {
+		return "", err
+	}
+
+	ret := sysname + " " + release + " " + version + " " + machine
+	return ret, nil
+}

src/cmd/internal/osinfo/os_uname.go

@@ -0,0 +1,47 @@
+// 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 aix || linux || solaris
+
+package osinfo
+
+import (
+	"bytes"
+	"strings"
+	"unsafe"
+)
+
+// Version returns the OS version name/number.
+func Version() (string, error) {
+	var uts utsname
+	if err := uname(&uts); err != nil {
+		return "", err
+	}
+
+	var sb strings.Builder
+
+	writeCStr := func(b []byte) {
+		if i := bytes.IndexByte(b, '\000'); i >= 0 {
+			b = b[:i]
+		}
+		sb.Write(b)
+	}
+
+	// We need some absurd conversions because syscall.Utsname
+	// sometimes uses []uint8 and sometimes []int8.
+
+	s := uts.Sysname[:]
+	writeCStr(*(*[]byte)(unsafe.Pointer(&s)))
+	sb.WriteByte(' ')
+	s = uts.Release[:]
+	writeCStr(*(*[]byte)(unsafe.Pointer(&s)))
+	sb.WriteByte(' ')
+	s = uts.Version[:]
+	writeCStr(*(*[]byte)(unsafe.Pointer(&s)))
+	sb.WriteByte(' ')
+	s = uts.Machine[:]
+	writeCStr(*(*[]byte)(unsafe.Pointer(&s)))
+
+	return sb.String(), nil
+}

src/cmd/internal/osinfo/version_unix_test.go

@@ -0,0 +1,26 @@
+// Copyright 2024 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 osinfo
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestVersion(t *testing.T) {
+	v, err := Version()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	t.Logf("%q", v)
+
+	fields := strings.Fields(v)
+	if len(fields) < 4 {
+		t.Errorf("wanted at least 4 fields in %q, got %d", v, len(fields))
+	}
+}