internal/syscall/unix: reuse existing {Fstat,Open,Unlink}at on freebsd

Change-Id: I517e75faca18bf0fdcd4e6c837f50f824aa6348c
Reviewed-on: https://go-review.googlesource.com/c/go/+/431236
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>

4 files changed, 18 insertions, 52 deletions

diff --git a/src/internal/syscall/unix/at.go b/src/internal/syscall/unix/at.go
index 90fcda0c75..cfb6e410b1 100644
--- a/src/internal/syscall/unix/at.go
+++ b/src/internal/syscall/unix/at.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build dragonfly || linux || netbsd || (openbsd && mips64)
+//go:build dragonfly || freebsd || linux || netbsd || (openbsd && mips64)
 
 package unix
 
diff --git a/src/internal/syscall/unix/at_freebsd.go b/src/internal/syscall/unix/at_freebsd.go
deleted file mode 100644
index e171f4dbb5..0000000000
--- a/src/internal/syscall/unix/at_freebsd.go
+++ /dev/null
@@ -1,47 +0,0 @@
-// Copyright 2018 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 unix
-
-import (
-	"syscall"
-	"unsafe"
-)
-
-const (
-	AT_REMOVEDIR        = 0x800
-	AT_SYMLINK_NOFOLLOW = 0x200
-)
-
-func Unlinkat(dirfd int, path string, flags int) error {
-	p, err := syscall.BytePtrFromString(path)
-	if err != nil {
-		return err
-	}
-
-	_, _, errno := syscall.Syscall(syscall.SYS_UNLINKAT, uintptr(dirfd), uintptr(unsafe.Pointer(p)), uintptr(flags))
-	if errno != 0 {
-		return errno
-	}
-
-	return nil
-}
-
-func Openat(dirfd int, path string, flags int, perm uint32) (int, error) {
-	p, err := syscall.BytePtrFromString(path)
-	if err != nil {
-		return 0, err
-	}
-
-	fd, _, errno := syscall.Syscall6(syscall.SYS_OPENAT, uintptr(dirfd), uintptr(unsafe.Pointer(p)), uintptr(flags), uintptr(perm), 0, 0)
-	if errno != 0 {
-		return 0, errno
-	}
-
-	return int(fd), nil
-}
-
-func Fstatat(dirfd int, path string, stat *syscall.Stat_t, flags int) error {
-	return syscall.Fstatat(dirfd, path, stat, flags)
-}
diff --git a/src/internal/syscall/unix/at_statx.go b/src/internal/syscall/unix/at_fstatat2.go
index 230d697b8c..8d20e1a885 100644
--- a/src/internal/syscall/unix/at_statx.go
+++ b/src/internal/syscall/unix/at_fstatat2.go
@@ -2,13 +2,11 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build linux && loong64
+//go:build freebsd || (linux && loong64)
 
 package unix
 
-import (
-	"syscall"
-)
+import "syscall"
 
 func Fstatat(dirfd int, path string, stat *syscall.Stat_t, flags int) error {
 	return syscall.Fstatat(dirfd, path, stat, flags)
diff --git a/src/internal/syscall/unix/at_sysnum_freebsd.go b/src/internal/syscall/unix/at_sysnum_freebsd.go
new file mode 100644
index 0000000000..adfbbcb92b
--- /dev/null
+++ b/src/internal/syscall/unix/at_sysnum_freebsd.go
@@ -0,0 +1,15 @@
+// Copyright 2018 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 unix
+
+import "syscall"
+
+const (
+	AT_REMOVEDIR        = 0x800
+	AT_SYMLINK_NOFOLLOW = 0x200
+
+	unlinkatTrap uintptr = syscall.SYS_UNLINKAT
+	openatTrap   uintptr = syscall.SYS_OPENAT
+)