Simplify Utsname string conversion (#716)

* Update golang.org/x/sys/unix

This allows to use simplified string conversion of Utsname members.

* Simplify Utsname string conversion

Use Utsname from golang.org/x/sys/unix which contains byte array
instead of int8/uint8 array members. This allows to simplify the string
conversions of these members.

collector/uname_linux.go

@@ -16,9 +16,11 @@
 package collector
 import (
-	"syscall"
+	"bytes"
 	"github.com/prometheus/client_golang/prometheus"
+
+	"golang.org/x/sys/unix"
 )
 var unameDesc = prometheus.NewDesc(
@@ -47,18 +49,18 @@ func newUnameCollector() (Collector, error) {
 }
 func (c unameCollector) Update(ch chan<- prometheus.Metric) error {
-	var uname syscall.Utsname
-	if err := syscall.Uname(&uname); err != nil {
+	var uname unix.Utsname
+	if err := unix.Uname(&uname); err != nil {
 		return err
 	}
 	ch <- prometheus.MustNewConstMetric(unameDesc, prometheus.GaugeValue, 1,
-		unameToString(uname.Sysname),
-		unameToString(uname.Release),
-		unameToString(uname.Version),
-		unameToString(uname.Machine),
-		unameToString(uname.Nodename),
-		unameToString(uname.Domainname),
+		string(uname.Sysname[:bytes.IndexByte(uname.Sysname[:], 0)]),
+		string(uname.Release[:bytes.IndexByte(uname.Release[:], 0)]),
+		string(uname.Version[:bytes.IndexByte(uname.Version[:], 0)]),
+		string(uname.Machine[:bytes.IndexByte(uname.Machine[:], 0)]),
+		string(uname.Nodename[:bytes.IndexByte(uname.Nodename[:], 0)]),
+		string(uname.Domainname[:bytes.IndexByte(uname.Domainname[:], 0)]),
 	)
 	return nil
 }

collector/uname_linux_int8.go

-// Copyright 2015 The Prometheus Authors
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// +build 386 amd64 arm64 mips64 mips64le mips mipsle
-// +build linux
-// +build !nouname
-
-package collector
-
-func unameToString(input [65]int8) string {
-	var str string
-	for _, a := range input {
-		if a == 0 {
-			break
-		}
-		str += string(a)
-	}
-	return str
-}

collector/uname_linux_uint8.go

-// Copyright 2015 The Prometheus Authors
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// +build !nouname,linux,arm !nouname,linux,ppc64 !nouname,linux,ppc64le !nouname,linux,s390x
-
-package collector
-
-func unameToString(input [65]uint8) string {
-	var str string
-	for _, a := range input {
-		if a == 0 {
-			break
-		}
-		str += string(a)
-	}
-	return str
-}

vendor/golang.org/x/sys/unix/env_unix.go

-// Copyright 2010 The Go Authors.  All rights reserved.
+// Copyright 2010 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.

vendor/golang.org/x/sys/unix/env_unset.go

-// Copyright 2014 The Go Authors.  All rights reserved.
+// Copyright 2014 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.

vendor/golang.org/x/sys/unix/gccgo.go

-// Copyright 2015 The Go Authors.  All rights reserved.
+// Copyright 2015 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.
@@ -8,7 +8,7 @@ package unix
 import "syscall"
-// We can't use the gc-syntax .s files for gccgo.  On the plus side
+// We can't use the gc-syntax .s files for gccgo. On the plus side
 // much of the functionality can be written directly in Go.
 //extern gccgoRealSyscall

vendor/golang.org/x/sys/unix/gccgo_c.c

-// Copyright 2015 The Go Authors.  All rights reserved.
+// Copyright 2015 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.

vendor/golang.org/x/sys/unix/gccgo_linux_amd64.go

-// Copyright 2015 The Go Authors.  All rights reserved.
+// Copyright 2015 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.

vendor/golang.org/x/sys/unix/mkall.sh

@@ -142,7 +142,6 @@ openbsd_386)
 	mkerrors="$mkerrors -m32"
 	mksyscall="./mksyscall.pl -l32 -openbsd"
 	mksysctl="./mksysctl_openbsd.pl"
-	zsysctl="zsysctl_openbsd.go"
 	mksysnum="curl -s 'http://cvsweb.openbsd.org/cgi-bin/cvsweb/~checkout~/src/sys/kern/syscalls.master' | ./mksysnum_openbsd.pl"
 	mktypes="GOARCH=$GOARCH go tool cgo -godefs"
 	;;
@@ -150,7 +149,6 @@ openbsd_amd64)
 	mkerrors="$mkerrors -m64"
 	mksyscall="./mksyscall.pl -openbsd"
 	mksysctl="./mksysctl_openbsd.pl"
-	zsysctl="zsysctl_openbsd.go"
 	mksysnum="curl -s 'http://cvsweb.openbsd.org/cgi-bin/cvsweb/~checkout~/src/sys/kern/syscalls.master' | ./mksysnum_openbsd.pl"
 	mktypes="GOARCH=$GOARCH go tool cgo -godefs"
 	;;
@@ -158,7 +156,6 @@ openbsd_arm)
 	mkerrors="$mkerrors"
 	mksyscall="./mksyscall.pl -l32 -openbsd -arm"
 	mksysctl="./mksysctl_openbsd.pl"
-	zsysctl="zsysctl_openbsd.go"
 	mksysnum="curl -s 'http://cvsweb.openbsd.org/cgi-bin/cvsweb/~checkout~/src/sys/kern/syscalls.master' | ./mksysnum_openbsd.pl"
 	# Let the type of C char be signed for making the bare syscall
 	# API consistent across platforms.

vendor/golang.org/x/sys/unix/mkerrors.sh

@@ -84,6 +84,7 @@ includes_FreeBSD='
 #include <sys/sockio.h>
 #include <sys/sysctl.h>
 #include <sys/mman.h>
+#include <sys/mount.h>
 #include <sys/wait.h>
 #include <sys/ioctl.h>
 #include <net/bpf.h>
@@ -183,6 +184,7 @@ struct ltchars {
 #include <linux/vm_sockets.h>
 #include <linux/taskstats.h>
 #include <linux/genetlink.h>
+#include <linux/watchdog.h>
 #include <net/route.h>
 #include <asm/termbits.h>
@@ -419,7 +421,9 @@ ccflags="$@"
 		$2 ~ /^(VM|VMADDR)_/ ||
 		$2 ~ /^(TASKSTATS|TS)_/ ||
 		$2 ~ /^GENL_/ ||
+		$2 ~ /^UTIME_/ ||
 		$2 ~ /^XATTR_(CREATE|REPLACE)/ ||
+		$2 ~ /^WDIOC_/ ||
 		$2 !~ "WMESGLEN" &&
 		$2 ~ /^W[A-Z0-9]+$/ ||
 		$2 ~ /^BLK[A-Z]*(GET$|SET$|BUF$|PART$|SIZE)/ {printf("\t%s = C.%s\n", $2, $2)}

vendor/golang.org/x/sys/unix/pagesize_unix.go

-// Copyright 2017 The Go Authors.  All rights reserved.
+// Copyright 2017 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.

vendor/golang.org/x/sys/unix/race.go

-// Copyright 2012 The Go Authors.  All rights reserved.
+// Copyright 2012 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.

vendor/golang.org/x/sys/unix/race0.go

-// Copyright 2012 The Go Authors.  All rights reserved.
+// Copyright 2012 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.

vendor/golang.org/x/sys/unix/sockcmsg_linux.go

-// Copyright 2011 The Go Authors.  All rights reserved.
+// Copyright 2011 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.

vendor/golang.org/x/sys/unix/syscall.go

@@ -5,10 +5,10 @@
 // +build darwin dragonfly freebsd linux netbsd openbsd solaris
 // Package unix contains an interface to the low-level operating system
-// primitives.  OS details vary depending on the underlying system, and
+// primitives. OS details vary depending on the underlying system, and
 // by default, godoc will display OS-specific documentation for the current
-// system.  If you want godoc to display OS documentation for another
-// system, set $GOOS and $GOARCH to the desired system.  For example, if
+// system. If you want godoc to display OS documentation for another
+// system, set $GOOS and $GOARCH to the desired system. For example, if
 // you want to view documentation for freebsd/arm on linux/amd64, set $GOOS
 // to freebsd and $GOARCH to arm.
 // The primary use of this package is inside other packages that provide a more
@@ -49,21 +49,3 @@ func BytePtrFromString(s string) (*byte, error) {
 // Single-word zero for use when we need a valid pointer to 0 bytes.
 // See mkunix.pl.
 var _zero uintptr
-
-func (ts *Timespec) Unix() (sec int64, nsec int64) {
-	return int64(ts.Sec), int64(ts.Nsec)
-}
-
-func (tv *Timeval) Unix() (sec int64, nsec int64) {
-	return int64(tv.Sec), int64(tv.Usec) * 1000
-}
-
-func (ts *Timespec) Nano() int64 {
-	return int64(ts.Sec)*1e9 + int64(ts.Nsec)
-}
-
-func (tv *Timeval) Nano() int64 {
-	return int64(tv.Sec)*1e9 + int64(tv.Usec)*1000
-}
-
-func TimevalToNsec(tv Timeval) int64 { return int64(tv.Sec)*1e9 + int64(tv.Usec)*1e3 }

vendor/golang.org/x/sys/unix/syscall_bsd.go

@@ -34,7 +34,7 @@ func Getgroups() (gids []int, err error) {
 		return nil, nil
 	}
-	// Sanity check group count.  Max is 16 on BSD.
+	// Sanity check group count. Max is 16 on BSD.
 	if n < 0 || n > 1000 {
 		return nil, EINVAL
 	}
@@ -607,6 +607,15 @@ func Futimes(fd int, tv []Timeval) error {
 //sys	fcntl(fd int, cmd int, arg int) (val int, err error)
+//sys   poll(fds *PollFd, nfds int, timeout int) (n int, err error)
+
+func Poll(fds []PollFd, timeout int) (n int, err error) {
+	if len(fds) == 0 {
+		return poll(nil, 0, timeout)
+	}
+	return poll(&fds[0], len(fds), timeout)
+}
+
 // TODO: wrap
 //	Acct(name nil-string) (err error)
 //	Gethostuuid(uuid *byte, timeout *Timespec) (err error)

vendor/golang.org/x/sys/unix/syscall_darwin.go

@@ -54,7 +54,7 @@ func nametomib(name string) (mib []_C_int, err error) {
 	// NOTE(rsc): It seems strange to set the buffer to have
 	// size CTL_MAXNAME+2 but use only CTL_MAXNAME
-	// as the size.  I don't know why the +2 is here, but the
+	// as the size. I don't know why the +2 is here, but the
 	// kernel uses +2 for its own implementation of this function.
 	// I am scared that if we don't include the +2 here, the kernel
 	// will silently write 2 words farther than we specify
@@ -377,7 +377,6 @@ func IoctlGetTermios(fd int, req uint) (*Termios, error) {
 // Searchfs
 // Delete
 // Copyfile
-// Poll
 // Watchevent
 // Waitevent
 // Modwatch

vendor/golang.org/x/sys/unix/syscall_darwin_386.go

@@ -11,25 +11,18 @@ import (
 	"unsafe"
 )
-func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
-
-func NsecToTimespec(nsec int64) (ts Timespec) {
-	ts.Sec = int32(nsec / 1e9)
-	ts.Nsec = int32(nsec % 1e9)
-	return
+func setTimespec(sec, nsec int64) Timespec {
+	return Timespec{Sec: int32(sec), Nsec: int32(nsec)}
 }
-func NsecToTimeval(nsec int64) (tv Timeval) {
-	nsec += 999 // round up to microsecond
-	tv.Usec = int32(nsec % 1e9 / 1e3)
-	tv.Sec = int32(nsec / 1e9)
-	return
+func setTimeval(sec, usec int64) Timeval {
+	return Timeval{Sec: int32(sec), Usec: int32(usec)}
 }
 //sysnb	gettimeofday(tp *Timeval) (sec int32, usec int32, err error)
 func Gettimeofday(tv *Timeval) (err error) {
 	// The tv passed to gettimeofday must be non-nil
-	// but is otherwise unused.  The answers come back
+	// but is otherwise unused. The answers come back
 	// in the two registers.
 	sec, usec, err := gettimeofday(tv)
 	tv.Sec = int32(sec)

vendor/golang.org/x/sys/unix/syscall_darwin_amd64.go

@@ -11,25 +11,18 @@ import (
 	"unsafe"
 )
-func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
-
-func NsecToTimespec(nsec int64) (ts Timespec) {
-	ts.Sec = nsec / 1e9
-	ts.Nsec = nsec % 1e9
-	return
+func setTimespec(sec, nsec int64) Timespec {
+	return Timespec{Sec: sec, Nsec: nsec}
 }
-func NsecToTimeval(nsec int64) (tv Timeval) {
-	nsec += 999 // round up to microsecond
-	tv.Usec = int32(nsec % 1e9 / 1e3)
-	tv.Sec = int64(nsec / 1e9)
-	return
+func setTimeval(sec, usec int64) Timeval {
+	return Timeval{Sec: sec, Usec: int32(usec)}
 }
 //sysnb	gettimeofday(tp *Timeval) (sec int64, usec int32, err error)
 func Gettimeofday(tv *Timeval) (err error) {
 	// The tv passed to gettimeofday must be non-nil
-	// but is otherwise unused.  The answers come back
+	// but is otherwise unused. The answers come back
 	// in the two registers.
 	sec, usec, err := gettimeofday(tv)
 	tv.Sec = sec

vendor/golang.org/x/sys/unix/syscall_darwin_arm.go

@@ -9,25 +9,18 @@ import (
 	"unsafe"
 )
-func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
-
-func NsecToTimespec(nsec int64) (ts Timespec) {
-	ts.Sec = int32(nsec / 1e9)
-	ts.Nsec = int32(nsec % 1e9)
-	return
+func setTimespec(sec, nsec int64) Timespec {
+	return Timespec{Sec: int32(sec), Nsec: int32(nsec)}
 }
-func NsecToTimeval(nsec int64) (tv Timeval) {
-	nsec += 999 // round up to microsecond
-	tv.Usec = int32(nsec % 1e9 / 1e3)
-	tv.Sec = int32(nsec / 1e9)
-	return
+func setTimeval(sec, usec int64) Timeval {
+	return Timeval{Sec: int32(sec), Usec: int32(usec)}
 }
 //sysnb	gettimeofday(tp *Timeval) (sec int32, usec int32, err error)
 func Gettimeofday(tv *Timeval) (err error) {
 	// The tv passed to gettimeofday must be non-nil
-	// but is otherwise unused.  The answers come back
+	// but is otherwise unused. The answers come back
 	// in the two registers.
 	sec, usec, err := gettimeofday(tv)
 	tv.Sec = int32(sec)