plan9: remove "use" function and calls from generated code.

Update mksyscall.pl to skip generating calls to "use".

See issue https://golang.org/issue/16607
and CL https://golang.org/cl/36616

Change-Id: Id36614fce5d98a8538edf4f4a7276e650b99b839
Reviewed-on: https://go-review.googlesource.com/c/156437
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

plan9/mksyscall.pl

@@ -132,7 +132,6 @@ while(<>) {
 
 	# Prepare arguments to Syscall.
 	my @args = ();
-	my @uses = ();
 	my $n = 0;
 	foreach my $p (@in) {
 		my ($name, $type) = parseparam($p);
@@ -143,14 +142,12 @@ while(<>) {
 			$text .= "\t_p$n, $errvar = BytePtrFromString($name)\n";
 			$text .= "\tif $errvar != nil {\n\t\treturn\n\t}\n";
 			push @args, "uintptr(unsafe.Pointer(_p$n))";
-			push @uses, "use(unsafe.Pointer(_p$n))";
 			$n++;
 		} elsif($type eq "string") {
 			print STDERR "$ARGV:$.: $func uses string arguments, but has no error return\n";
 			$text .= "\tvar _p$n *byte\n";
 			$text .= "\t_p$n, _ = BytePtrFromString($name)\n";
 			push @args, "uintptr(unsafe.Pointer(_p$n))";
-			push @uses, "use(unsafe.Pointer(_p$n))";
 			$n++;
 		} elsif($type =~ /^\[\](.*)/) {
 			# Convert slice into pointer, length.
@@ -281,9 +278,6 @@ while(<>) {
 	} else {
 		$text .= "\t$ret[0], $ret[1], $ret[2] := $call\n";
 	}
-	foreach my $use (@uses) {
-		$text .= "\t$use\n";
-	}
 	$text .= $body;
 	
 	if ($plan9 && $ret[2] eq "e1") {

plan9/zsyscall_plan9_386.go

@@ -57,7 +57,6 @@ func open(path string, mode int) (fd int, err error) {
 		return
 	}
 	r0, _, e1 := Syscall(SYS_OPEN, uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
-	use(unsafe.Pointer(_p0))
 	fd = int(r0)
 	if int32(r0) == -1 {
 		err = e1
@@ -74,7 +73,6 @@ func create(path string, mode int, perm uint32) (fd int, err error) {
 		return
 	}
 	r0, _, e1 := Syscall(SYS_CREATE, uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(perm))
-	use(unsafe.Pointer(_p0))
 	fd = int(r0)
 	if int32(r0) == -1 {
 		err = e1
@@ -91,7 +89,6 @@ func remove(path string) (err error) {
 		return
 	}
 	r0, _, e1 := Syscall(SYS_REMOVE, uintptr(unsafe.Pointer(_p0)), 0, 0)
-	use(unsafe.Pointer(_p0))
 	if int32(r0) == -1 {
 		err = e1
 	}
@@ -113,7 +110,6 @@ func stat(path string, edir []byte) (n int, err error) {
 		_p1 = unsafe.Pointer(&_zero)
 	}
 	r0, _, e1 := Syscall(SYS_STAT, uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(edir)))
-	use(unsafe.Pointer(_p0))
 	n = int(r0)
 	if int32(r0) == -1 {
 		err = e1
@@ -135,8 +131,6 @@ func bind(name string, old string, flag int) (err error) {
 		return
 	}
 	r0, _, e1 := Syscall(SYS_BIND, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(flag))
-	use(unsafe.Pointer(_p0))
-	use(unsafe.Pointer(_p1))
 	if int32(r0) == -1 {
 		err = e1
 	}
@@ -157,8 +151,6 @@ func mount(fd int, afd int, old string, flag int, aname string) (err error) {
 		return
 	}
 	r0, _, e1 := Syscall6(SYS_MOUNT, uintptr(fd), uintptr(afd), uintptr(unsafe.Pointer(_p0)), uintptr(flag), uintptr(unsafe.Pointer(_p1)), 0)
-	use(unsafe.Pointer(_p0))
-	use(unsafe.Pointer(_p1))
 	if int32(r0) == -1 {
 		err = e1
 	}
@@ -180,7 +172,6 @@ func wstat(path string, edir []byte) (err error) {
 		_p1 = unsafe.Pointer(&_zero)
 	}
 	r0, _, e1 := Syscall(SYS_WSTAT, uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(edir)))
-	use(unsafe.Pointer(_p0))
 	if int32(r0) == -1 {
 		err = e1
 	}
@@ -196,7 +187,6 @@ func chdir(path string) (err error) {
 		return
 	}
 	r0, _, e1 := Syscall(SYS_CHDIR, uintptr(unsafe.Pointer(_p0)), 0, 0)
-	use(unsafe.Pointer(_p0))
 	if int32(r0) == -1 {
 		err = e1
 	}

plan9/zsyscall_plan9_amd64.go

@@ -57,7 +57,6 @@ func open(path string, mode int) (fd int, err error) {
 		return
 	}
 	r0, _, e1 := Syscall(SYS_OPEN, uintptr(unsafe.Pointer(_p0)), uintptr(mode), 0)
-	use(unsafe.Pointer(_p0))
 	fd = int(r0)
 	if int32(r0) == -1 {
 		err = e1
@@ -74,7 +73,6 @@ func create(path string, mode int, perm uint32) (fd int, err error) {
 		return
 	}
 	r0, _, e1 := Syscall(SYS_CREATE, uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(perm))
-	use(unsafe.Pointer(_p0))
 	fd = int(r0)
 	if int32(r0) == -1 {
 		err = e1
@@ -91,7 +89,6 @@ func remove(path string) (err error) {
 		return
 	}
 	r0, _, e1 := Syscall(SYS_REMOVE, uintptr(unsafe.Pointer(_p0)), 0, 0)
-	use(unsafe.Pointer(_p0))
 	if int32(r0) == -1 {
 		err = e1
 	}
@@ -113,7 +110,6 @@ func stat(path string, edir []byte) (n int, err error) {
 		_p1 = unsafe.Pointer(&_zero)
 	}
 	r0, _, e1 := Syscall(SYS_STAT, uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(edir)))
-	use(unsafe.Pointer(_p0))
 	n = int(r0)
 	if int32(r0) == -1 {
 		err = e1
@@ -135,8 +131,6 @@ func bind(name string, old string, flag int) (err error) {
 		return
 	}
 	r0, _, e1 := Syscall(SYS_BIND, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(flag))
-	use(unsafe.Pointer(_p0))
-	use(unsafe.Pointer(_p1))
 	if int32(r0) == -1 {
 		err = e1
 	}
@@ -157,8 +151,6 @@ func mount(fd int, afd int, old string, flag int, aname string) (err error) {
 		return
 	}
 	r0, _, e1 := Syscall6(SYS_MOUNT, uintptr(fd), uintptr(afd), uintptr(unsafe.Pointer(_p0)), uintptr(flag), uintptr(unsafe.Pointer(_p1)), 0)
-	use(unsafe.Pointer(_p0))
-	use(unsafe.Pointer(_p1))
 	if int32(r0) == -1 {
 		err = e1
 	}
@@ -180,7 +172,6 @@ func wstat(path string, edir []byte) (err error) {
 		_p1 = unsafe.Pointer(&_zero)
 	}
 	r0, _, e1 := Syscall(SYS_WSTAT, uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(edir)))
-	use(unsafe.Pointer(_p0))
 	if int32(r0) == -1 {
 		err = e1
 	}
@@ -196,7 +187,6 @@ func chdir(path string) (err error) {
 		return
 	}
 	r0, _, e1 := Syscall(SYS_CHDIR, uintptr(unsafe.Pointer(_p0)), 0, 0)
-	use(unsafe.Pointer(_p0))
 	if int32(r0) == -1 {
 		err = e1
 	}