From e8e29180ff5864b319bc2075950ef6e6f458e8b3 Mon Sep 17 00:00:00 2001
From: Tobias Klauser <tklauser@distanz.ch>
Date: Wed, 13 Jan 2021 18:56:56 +0100
Subject: [PATCH] unix: fix Pipe2 on dragonfly

Also move TestPipe2 into a separate file, enabling it for all platforms
where Pipe2 is available.

Change-Id: I9c554a53fc9d7610aaa732c0ceba864963fad542
Reviewed-on: https://go-review.googlesource.com/c/sys/+/283598
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
---
 unix/pipe2_test.go               | 55 ++++++++++++++++++++++++++++++++
 unix/syscall_dragonfly.go        |  9 ++----
 unix/syscall_solaris_test.go     | 42 ------------------------
 unix/zsyscall_dragonfly_amd64.go |  6 ++--
 4 files changed, 62 insertions(+), 50 deletions(-)
 create mode 100644 unix/pipe2_test.go

diff --git a/unix/pipe2_test.go b/unix/pipe2_test.go
new file mode 100644
index 00000000..3e1c01fe
--- /dev/null
+++ b/unix/pipe2_test.go
@@ -0,0 +1,55 @@
+// Copyright 2021 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.
+
+// +build dragonfly freebsd linux openbsd solaris
+
+package unix_test
+
+import (
+	"testing"
+
+	"golang.org/x/sys/unix"
+)
+
+func TestPipe2(t *testing.T) {
+	const s = "hello"
+	var pipes [2]int
+	err := unix.Pipe2(pipes[:], 0)
+	if err != nil {
+		t.Fatalf("pipe2: %v", err)
+	}
+	r := pipes[0]
+	w := pipes[1]
+	go func() {
+		n, err := unix.Write(w, []byte(s))
+		if err != nil {
+			t.Errorf("bad write: %v", err)
+			return
+		}
+		if n != len(s) {
+			t.Errorf("bad write count: %d", n)
+			return
+		}
+		err = unix.Close(w)
+		if err != nil {
+			t.Errorf("bad close: %v", err)
+			return
+		}
+	}()
+	var buf [10 + len(s)]byte
+	n, err := unix.Read(r, buf[:])
+	if err != nil {
+		t.Fatalf("bad read: %v", err)
+	}
+	if n != len(s) {
+		t.Fatalf("bad read count: %d", n)
+	}
+	if string(buf[:n]) != s {
+		t.Fatalf("bad contents: %s", string(buf[:n]))
+	}
+	err = unix.Close(r)
+	if err != nil {
+		t.Fatalf("bad close: %v", err)
+	}
+}
diff --git a/unix/syscall_dragonfly.go b/unix/syscall_dragonfly.go
index 7629878b..474141b6 100644
--- a/unix/syscall_dragonfly.go
+++ b/unix/syscall_dragonfly.go
@@ -105,16 +105,13 @@ func Pipe(p []int) (err error) {
 	return
 }
 
-//sysnb	pipe2(p *[2]_C_int, flags int) (err error)
+//sysnb	pipe2(flags int) (r int, w int, err error)
 
-func Pipe2(p []int, flags int) error {
+func Pipe2(p []int, flags int) (err error) {
 	if len(p) != 2 {
 		return EINVAL
 	}
-	var pp [2]_C_int
-	err := pipe2(&pp, flags)
-	p[0] = int(pp[0])
-	p[1] = int(pp[1])
+	p[0], p[1], err = pipe2(flags)
 	return err
 }
 
diff --git a/unix/syscall_solaris_test.go b/unix/syscall_solaris_test.go
index f4d73a85..7734e124 100644
--- a/unix/syscall_solaris_test.go
+++ b/unix/syscall_solaris_test.go
@@ -13,48 +13,6 @@ import (
 	"golang.org/x/sys/unix"
 )
 
-func TestPipe2(t *testing.T) {
-	const s = "hello"
-	var pipes [2]int
-	err := unix.Pipe2(pipes[:], 0)
-	if err != nil {
-		t.Fatalf("pipe2: %v", err)
-	}
-	r := pipes[0]
-	w := pipes[1]
-	go func() {
-		n, err := unix.Write(w, []byte(s))
-		if err != nil {
-			t.Errorf("bad write: %v", err)
-			return
-		}
-		if n != len(s) {
-			t.Errorf("bad write count: %d", n)
-			return
-		}
-		err = unix.Close(w)
-		if err != nil {
-			t.Errorf("bad close: %v", err)
-			return
-		}
-	}()
-	var buf [10 + len(s)]byte
-	n, err := unix.Read(r, buf[:])
-	if err != nil {
-		t.Fatalf("bad read: %v", err)
-	}
-	if n != len(s) {
-		t.Fatalf("bad read count: %d", n)
-	}
-	if string(buf[:n]) != s {
-		t.Fatalf("bad contents: %s", string(buf[:n]))
-	}
-	err = unix.Close(r)
-	if err != nil {
-		t.Fatalf("bad close: %v", err)
-	}
-}
-
 func TestStatvfs(t *testing.T) {
 	if err := unix.Statvfs("", nil); err == nil {
 		t.Fatal(`Statvfs("") expected failure`)
diff --git a/unix/zsyscall_dragonfly_amd64.go b/unix/zsyscall_dragonfly_amd64.go
index 1aaccd36..104f77d5 100644
--- a/unix/zsyscall_dragonfly_amd64.go
+++ b/unix/zsyscall_dragonfly_amd64.go
@@ -362,8 +362,10 @@ func pipe() (r int, w int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func pipe2(p *[2]_C_int, flags int) (err error) {
-	_, _, e1 := RawSyscall(SYS_PIPE2, uintptr(unsafe.Pointer(p)), uintptr(flags), 0)
+func pipe2(flags int) (r int, w int, err error) {
+	r0, r1, e1 := RawSyscall(SYS_PIPE2, uintptr(flags), 0, 0)
+	r = int(r0)
+	w = int(r1)
 	if e1 != 0 {
 		err = errnoErr(e1)
 	}