os: split wait6 syscall wrapper into per-platform files

There are getting to be enough special cases in this wrapper that
the increase in clarity from having a single file is starting to be
outweighed by the complexity from chained conditionals.

Updates #50138.
Updates #13987.

Change-Id: If4f1be19c0344e249aa6092507c28363ca6c8438
Reviewed-on: https://go-review.googlesource.com/c/go/+/442575
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Bryan Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>

diff --git a/src/os/wait6_dragonfly.go b/src/os/wait6_dragonfly.go
new file mode 100644 (file)
index 0000000..cc3af39
--- /dev/null
+++ b/src/os/wait6_dragonfly.go
@@ -0,0 +1,18 @@
+// 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.
+
+package os
+
+import (
+       "syscall"
+       "unsafe"
+)
+
+const _P_PID = 0
+
+func wait6(idtype, id, options int) (status int, errno syscall.Errno) {
+       var status32 int32 // C.int
+       _, _, errno = syscall.Syscall6(syscall.SYS_WAIT6, uintptr(idtype), uintptr(id), uintptr(unsafe.Pointer(&status32)), uintptr(options), 0, 0)
+       return int(status32), errno
+}

diff --git a/src/os/wait6_freebsd64.go b/src/os/wait6_freebsd64.go
new file mode 100644 (file)
index 0000000..b2677c5
--- /dev/null
+++ b/src/os/wait6_freebsd64.go
@@ -0,0 +1,20 @@
+// 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 freebsd && (amd64 || arm64 || riscv64)
+
+package os
+
+import (
+       "syscall"
+       "unsafe"
+)
+
+const _P_PID = 0
+
+func wait6(idtype, id, options int) (status int, errno syscall.Errno) {
+       var status32 int32 // C.int
+       _, _, errno = syscall.Syscall6(syscall.SYS_WAIT6, uintptr(idtype), uintptr(id), uintptr(unsafe.Pointer(&status32)), uintptr(options), 0, 0)
+       return int(status32), errno
+}

diff --git a/src/os/wait6_freebsd_386.go b/src/os/wait6_freebsd_386.go
new file mode 100644 (file)
index 0000000..30b01c5
--- /dev/null
+++ b/src/os/wait6_freebsd_386.go
@@ -0,0 +1,18 @@
+// 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.
+
+package os
+
+import (
+       "syscall"
+       "unsafe"
+)
+
+const _P_PID = 0
+
+func wait6(idtype, id, options int) (status int, errno syscall.Errno) {
+       // freebsd32_wait6_args{ idtype, id1, id2, status, options, wrusage, info }
+       _, _, errno = syscall.Syscall9(syscall.SYS_WAIT6, uintptr(idtype), uintptr(id), 0, uintptr(unsafe.Pointer(&status)), uintptr(options), 0, 0, 0, 0)
+       return status, errno
+}

diff --git a/src/os/wait6_freebsd_arm.go b/src/os/wait6_freebsd_arm.go
new file mode 100644 (file)
index 0000000..0fd8af0
--- /dev/null
+++ b/src/os/wait6_freebsd_arm.go
@@ -0,0 +1,18 @@
+// 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.
+
+package os
+
+import (
+       "syscall"
+       "unsafe"
+)
+
+const _P_PID = 0
+
+func wait6(idtype, id, options int) (status int, errno syscall.Errno) {
+       // freebsd32_wait6_args{ idtype, pad, id1, id2, status, options, wrusage, info }
+       _, _, errno = syscall.Syscall9(syscall.SYS_WAIT6, uintptr(idtype), 0, uintptr(id), 0, uintptr(unsafe.Pointer(&status)), uintptr(options), 0, 0, 0)
+       return status, errno
+}

diff --git a/src/os/wait6_netbsd.go b/src/os/wait6_netbsd.go
new file mode 100644 (file)
index 0000000..0bbb73d
--- /dev/null
+++ b/src/os/wait6_netbsd.go
@@ -0,0 +1,18 @@
+// 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.
+
+package os
+
+import (
+       "syscall"
+       "unsafe"
+)
+
+const _P_PID = 1 // not 0 as on FreeBSD and Dragonfly!
+
+func wait6(idtype, id, options int) (status int, errno syscall.Errno) {
+       var status32 int32 // C.int
+       _, _, errno = syscall.Syscall6(syscall.SYS_WAIT6, uintptr(idtype), uintptr(id), uintptr(unsafe.Pointer(&status32)), uintptr(options), 0, 0)
+       return int(status32), errno
+}

diff --git a/src/os/wait_wait6.go b/src/os/wait_wait6.go
index e5cf87b1356f4e03eb7dd9516b81d2f47473cb14..1031428826ca667478fbe868b96582f1e3eedbf4 100644 (file)
--- a/src/os/wait_wait6.go
+++ b/src/os/wait_wait6.go
@@ -11,29 +11,13 @@ import (
        "syscall"
 )
 
-const (
-       _P_PID        = 0 // everywhere except for NetBSD?
-       _P_PID_NETBSD = 1 // on NetBSD, 0 is P_ALL
-)
-
 // blockUntilWaitable attempts to block until a call to p.Wait will
 // succeed immediately, and reports whether it has done so.
 // It does not actually call p.Wait.
 func (p *Process) blockUntilWaitable() (bool, error) {
        var errno syscall.Errno
        for {
-               // The arguments on 32-bit FreeBSD look like the following:
-               // - freebsd32_wait6_args{ idtype, id1, id2, status, options, wrusage, info } or
-               // - freebsd32_wait6_args{ idtype, pad, id1, id2, status, options, wrusage, info } when PAD64_REQUIRED=1 on ARM, MIPS or PowerPC
-               if runtime.GOOS == "freebsd" && runtime.GOARCH == "386" {
-                       _, _, errno = syscall.Syscall9(syscall.SYS_WAIT6, _P_PID, uintptr(p.Pid), 0, 0, syscall.WEXITED|syscall.WNOWAIT, 0, 0, 0, 0)
-               } else if runtime.GOOS == "freebsd" && runtime.GOARCH == "arm" {
-                       _, _, errno = syscall.Syscall9(syscall.SYS_WAIT6, _P_PID, 0, uintptr(p.Pid), 0, 0, syscall.WEXITED|syscall.WNOWAIT, 0, 0, 0)
-               } else if runtime.GOOS == "netbsd" {
-                       _, _, errno = syscall.Syscall6(syscall.SYS_WAIT6, _P_PID_NETBSD, uintptr(p.Pid), 0, syscall.WEXITED|syscall.WNOWAIT, 0, 0)
-               } else {
-                       _, _, errno = syscall.Syscall6(syscall.SYS_WAIT6, _P_PID, uintptr(p.Pid), 0, syscall.WEXITED|syscall.WNOWAIT, 0, 0)
-               }
+               _, errno = wait6(_P_PID, p.Pid, syscall.WEXITED|syscall.WNOWAIT)
                if errno != syscall.EINTR {
                        break
                }