unix: remove unused readlen and writelen

These were originally added when copying over files from package
syscall. However, their use was removed in CL 129500043. New ports kept
adding these wrappers without using them. They are still unused, so
remove them.

Change-Id: I2ffffe98a5c999d23b63d1f04ee4ad8f807ee736
Reviewed-on: https://go-review.googlesource.com/c/sys/+/531356
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>

unix/mksyscall.go

@@ -373,7 +373,7 @@ func main() {
 			text += "}\n\n"
 
 			if *libc && !trampolines[libcFn] {
-				// some system calls share a trampoline, like read and readlen.
+				// Some system calls share a trampoline.
 				trampolines[libcFn] = true
 				// Declare assembly trampoline address.
 				text += fmt.Sprintf("var libc_%s_trampoline_addr uintptr\n\n", libcFn)

unix/mksyscall_aix_ppc.go

@@ -217,7 +217,7 @@ func main() {
 				}
 			}
 
-			if funct != "fcntl" && funct != "FcntlInt" && funct != "readlen" && funct != "writelen" && funct != "ioctlPtr" {
+			if funct != "fcntl" && funct != "FcntlInt" && funct != "ioctlPtr" {
 				if sysname == "select" {
 					// select is a keyword of Go. Its name is
 					// changed to c_select.
@@ -296,9 +296,7 @@ func main() {
 				} else if p.Type == "unsafe.Pointer" {
 					args = append(args, fmt.Sprintf("C.uintptr_t(uintptr(%s))", p.Name))
 				} else if p.Type == "int" {
-					if (argN == 2) && ((funct == "readlen") || (funct == "writelen")) {
-						args = append(args, fmt.Sprintf("C.size_t(%s)", p.Name))
-					} else if argN == 0 && funct == "fcntl" {
+					if argN == 0 && funct == "fcntl" {
 						args = append(args, fmt.Sprintf("C.uintptr_t(%s)", p.Name))
 					} else if (argN == 2) && ((funct == "fcntl") || (funct == "FcntlInt")) {
 						args = append(args, fmt.Sprintf("C.uintptr_t(%s)", p.Name))

unix/mksyscall_aix_ppc64.go

@@ -189,7 +189,7 @@ func main() {
 			}
 
 			onlyCommon := false
-			if funct == "readlen" || funct == "writelen" || funct == "FcntlInt" || funct == "FcntlFlock" || funct == "ioctlPtr" {
+			if funct == "FcntlInt" || funct == "FcntlFlock" || funct == "ioctlPtr" {
 				// This function call another syscall which is already implemented.
 				// Therefore, the gc and gccgo part must not be generated.
 				onlyCommon = true

unix/syscall_aix.go

@@ -487,8 +487,6 @@ func Fsync(fd int) error {
 //sys	Unlinkat(dirfd int, path string, flags int) (err error)
 //sys	Ustat(dev int, ubuf *Ustat_t) (err error)
 //sys	write(fd int, p []byte) (n int, err error)
-//sys	readlen(fd int, p *byte, np int) (n int, err error) = read
-//sys	writelen(fd int, p *byte, np int) (n int, err error) = write
 
 //sys	Dup2(oldfd int, newfd int) (err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = posix_fadvise64

unix/syscall_darwin.go

@@ -644,5 +644,3 @@ func SysctlKinfoProcSlice(name string, args ...int) ([]KinfoProc, error) {
 //sys	write(fd int, p []byte) (n int, err error)
 //sys	mmap(addr uintptr, length uintptr, prot int, flag int, fd int, pos int64) (ret uintptr, err error)
 //sys	munmap(addr uintptr, length uintptr) (err error)
-//sys	readlen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_READ
-//sys	writelen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_WRITE

unix/syscall_dragonfly.go

@@ -343,7 +343,5 @@ func Sendfile(outfd int, infd int, offset *int64, count int) (written int, err e
 //sys	write(fd int, p []byte) (n int, err error)
 //sys	mmap(addr uintptr, length uintptr, prot int, flag int, fd int, pos int64) (ret uintptr, err error)
 //sys	munmap(addr uintptr, length uintptr) (err error)
-//sys	readlen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_READ
-//sys	writelen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_WRITE
 //sys	accept4(fd int, rsa *RawSockaddrAny, addrlen *_Socklen, flags int) (nfd int, err error)
 //sys	utimensat(dirfd int, path string, times *[2]Timespec, flags int) (err error)

unix/syscall_freebsd.go

@@ -449,7 +449,5 @@ func Dup3(oldfd, newfd, flags int) error {
 //sys	write(fd int, p []byte) (n int, err error)
 //sys	mmap(addr uintptr, length uintptr, prot int, flag int, fd int, pos int64) (ret uintptr, err error)
 //sys	munmap(addr uintptr, length uintptr) (err error)
-//sys	readlen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_READ
-//sys	writelen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_WRITE
 //sys	accept4(fd int, rsa *RawSockaddrAny, addrlen *_Socklen, flags int) (nfd int, err error)
 //sys	utimensat(dirfd int, path string, times *[2]Timespec, flags int) (err error)

unix/syscall_linux.go

@@ -1979,8 +1979,6 @@ func Signalfd(fd int, sigmask *Sigset_t, flags int) (newfd int, err error) {
 //sys	Unshare(flags int) (err error)
 //sys	write(fd int, p []byte) (n int, err error)
 //sys	exitThread(code int) (err error) = SYS_EXIT
-//sys	readlen(fd int, p *byte, np int) (n int, err error) = SYS_READ
-//sys	writelen(fd int, p *byte, np int) (n int, err error) = SYS_WRITE
 //sys	readv(fd int, iovs []Iovec) (n int, err error) = SYS_READV
 //sys	writev(fd int, iovs []Iovec) (n int, err error) = SYS_WRITEV
 //sys	preadv(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr) (n int, err error) = SYS_PREADV

unix/syscall_netbsd.go

@@ -356,8 +356,6 @@ func Statvfs(path string, buf *Statvfs_t) (err error) {
 //sys	write(fd int, p []byte) (n int, err error)
 //sys	mmap(addr uintptr, length uintptr, prot int, flag int, fd int, pos int64) (ret uintptr, err error)
 //sys	munmap(addr uintptr, length uintptr) (err error)
-//sys	readlen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_READ
-//sys	writelen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_WRITE
 //sys	utimensat(dirfd int, path string, times *[2]Timespec, flags int) (err error)
 
 const (

unix/syscall_openbsd.go

@@ -326,6 +326,4 @@ func Uname(uname *Utsname) error {
 //sys	write(fd int, p []byte) (n int, err error)
 //sys	mmap(addr uintptr, length uintptr, prot int, flag int, fd int, pos int64) (ret uintptr, err error)
 //sys	munmap(addr uintptr, length uintptr) (err error)
-//sys	readlen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_READ
-//sys	writelen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_WRITE
 //sys	utimensat(dirfd int, path string, times *[2]Timespec, flags int) (err error)

unix/syscall_solaris.go

@@ -698,24 +698,6 @@ func Sendfile(outfd int, infd int, offset *int64, count int) (written int, err e
 //sys	setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error) = libsocket.setsockopt
 //sys	recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error) = libsocket.recvfrom
 
-func readlen(fd int, buf *byte, nbuf int) (n int, err error) {
-	r0, _, e1 := sysvicall6(uintptr(unsafe.Pointer(&procread)), 3, uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf), 0, 0, 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-func writelen(fd int, buf *byte, nbuf int) (n int, err error) {
-	r0, _, e1 := sysvicall6(uintptr(unsafe.Pointer(&procwrite)), 3, uintptr(fd), uintptr(unsafe.Pointer(buf)), uintptr(nbuf), 0, 0, 0)
-	n = int(r0)
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
 // Event Ports
 
 type fileObjCookie struct {

unix/syscall_zos_s390x.go

@@ -192,7 +192,6 @@ func (cmsg *Cmsghdr) SetLen(length int) {
 
 //sys   fcntl(fd int, cmd int, arg int) (val int, err error)
 //sys	read(fd int, p []byte) (n int, err error)
-//sys   readlen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_READ
 //sys	write(fd int, p []byte) (n int, err error)
 
 //sys	accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error) = SYS___ACCEPT_A