Revert "syscall, os: use pipe2 syscall on DragonflyBSD instead of pipe"

This reverts commit e6c15945dee0661dee6111183d4951853c4c2d98.

Reason for revert: breaks the Dragonfly builders.

Fixes #27245

Change-Id: I2c147a5726aec28647f6ef5eb8f9db5efa3a9fd0
Reviewed-on: https://go-review.googlesource.com/131497
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

7 files changed, 9 insertions, 14 deletions

diff --git a/src/os/pipe2_bsd.go b/src/os/pipe2_bsd.go
index 7d2d9e8ffd..0ef894b476 100644
--- a/src/os/pipe2_bsd.go
+++ b/src/os/pipe2_bsd.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.
 
-// +build dragonfly freebsd netbsd openbsd
+// +build freebsd netbsd openbsd
 
 package os
 
diff --git a/src/os/pipe_bsd.go b/src/os/pipe_bsd.go
index 6fd10dbc1a..9735988f32 100644
--- a/src/os/pipe_bsd.go
+++ b/src/os/pipe_bsd.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.
 
-// +build darwin js,wasm nacl solaris
+// +build darwin dragonfly js,wasm nacl solaris
 
 package os
 
diff --git a/src/syscall/forkpipe.go b/src/syscall/forkpipe.go
index 55777497b1..71890a29ba 100644
--- a/src/syscall/forkpipe.go
+++ b/src/syscall/forkpipe.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.
 
-// +build darwin solaris
+// +build darwin dragonfly solaris
 
 package syscall
 
diff --git a/src/syscall/forkpipe2.go b/src/syscall/forkpipe2.go
index 0078f4bbab..c9a0c4996e 100644
--- a/src/syscall/forkpipe2.go
+++ b/src/syscall/forkpipe2.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.
 
-// +build dragonfly freebsd netbsd openbsd
+// +build freebsd netbsd openbsd
 
 package syscall
 
diff --git a/src/syscall/syscall_dragonfly.go b/src/syscall/syscall_dragonfly.go
index d59f139446..3dbbe342cf 100644
--- a/src/syscall/syscall_dragonfly.go
+++ b/src/syscall/syscall_dragonfly.go
@@ -72,17 +72,13 @@ func direntNamlen(buf []byte) (uint64, bool) {
 	return readInt(buf, unsafe.Offsetof(Dirent{}.Namlen), unsafe.Sizeof(Dirent{}.Namlen))
 }
 
-func Pipe(p []int) error {
-	return Pipe2(p, 0)
-}
-
-//sysnb pipe2(flags int) (r int, w int, err error)
+//sysnb pipe() (r int, w int, err error)
 
-func Pipe2(p []int, flags int) (err error) {
+func Pipe(p []int) (err error) {
 	if len(p) != 2 {
 		return EINVAL
 	}
-	p[0], p[1], err = pipe2(flags)
+	p[0], p[1], err = pipe()
 	return
 }
 
diff --git a/src/syscall/zsyscall_dragonfly_amd64.go b/src/syscall/zsyscall_dragonfly_amd64.go
index f9ed33aae8..578b5a3e9e 100644
--- a/src/syscall/zsyscall_dragonfly_amd64.go
+++ b/src/syscall/zsyscall_dragonfly_amd64.go
@@ -261,8 +261,8 @@ func fcntl(fd int, cmd int, arg int) (val int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func pipe2(flags int) (r int, w int, err error) {
-	r0, r1, e1 := RawSyscall(SYS_PIPE2, uintptr(flags), 0, 0)
+func pipe() (r int, w int, err error) {
+	r0, r1, e1 := RawSyscall(SYS_PIPE, 0, 0, 0)
 	r = int(r0)
 	w = int(r1)
 	if e1 != 0 {
diff --git a/src/syscall/zsysnum_dragonfly_amd64.go b/src/syscall/zsysnum_dragonfly_amd64.go
index 58582b9e7a..9ce11f5899 100644
--- a/src/syscall/zsysnum_dragonfly_amd64.go
+++ b/src/syscall/zsysnum_dragonfly_amd64.go
@@ -301,7 +301,6 @@ const (
 	SYS_LPATHCONF              = 533 // { int lpathconf(char *path, int name); }
 	SYS_VMM_GUEST_CTL          = 534 // { int vmm_guest_ctl(int op, struct vmm_guest_options *options); }
 	SYS_VMM_GUEST_SYNC_ADDR    = 535 // { int vmm_guest_sync_addr(long *dstaddr, long *srcaddr); }
-	SYS_PIPE2                  = 538 // { int pipe2(int *fildes, int flags); }
 	SYS_UTIMENSAT              = 539 // { int utimensat(int fd, const char *path, const struct timespec *ts, int flags); }
 	SYS_ACCEPT4                = 541 // { int accept4(int s, caddr_t name, int *anamelen, int flags); }
 )