net: use internal/bytealg insetad of linkname tricks

We are currently using go:linkname for some algorithms from
strings/bytes packages, to avoid importing strings/bytes.
But strings/bytes are just wrappers around internal/bytealg, so
we should use internal/bytealg directly.

Change-Id: I2836f779b88bf8876d5fa725043a6042bdda0390
Reviewed-on: https://go-review.googlesource.com/130515
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/net/conf.go

@@ -7,6 +7,7 @@
 package net
 
 import (
+	"internal/bytealg"
 	"os"
 	"runtime"
 	"sync"
@@ -132,7 +133,7 @@ func (c *conf) hostLookupOrder(r *Resolver, hostname string) (ret hostLookupOrde
 	if c.forceCgoLookupHost || c.resolv.unknownOpt || c.goos == "android" {
 		return fallbackOrder
 	}
-	if byteIndex(hostname, '\\') != -1 || byteIndex(hostname, '%') != -1 {
+	if bytealg.IndexByteString(hostname, '\\') != -1 || bytealg.IndexByteString(hostname, '%') != -1 {
 		// Don't deal with special form hostnames with backslashes
 		// or '%'.
 		return fallbackOrder
@@ -301,7 +302,7 @@ func goDebugNetDNS() (dnsMode string, debugLevel int) {
 			dnsMode = s
 		}
 	}
-	if i := byteIndex(goDebug, '+'); i != -1 {
+	if i := bytealg.IndexByteString(goDebug, '+'); i != -1 {
 		parsePart(goDebug[:i])
 		parsePart(goDebug[i+1:])
 		return

src/net/dnsconfig_unix.go

@@ -9,6 +9,7 @@
 package net
 
 import (
+	"internal/bytealg"
 	"os"
 	"sync/atomic"
 	"time"
@@ -155,7 +156,7 @@ func dnsDefaultSearch() []string {
 		// best effort
 		return nil
 	}
-	if i := byteIndex(hn, '.'); i >= 0 && i < len(hn)-1 {
+	if i := bytealg.IndexByteString(hn, '.'); i >= 0 && i < len(hn)-1 {
 		return []string{ensureRooted(hn[i+1:])}
 	}
 	return nil

src/net/hosts.go

@@ -5,6 +5,7 @@
 package net
 
 import (
+	"internal/bytealg"
 	"sync"
 	"time"
 )
@@ -68,7 +69,7 @@ func readHosts() {
 		return
 	}
 	for line, ok := file.readLine(); ok; line, ok = file.readLine() {
-		if i := byteIndex(line, '#'); i >= 0 {
+		if i := bytealg.IndexByteString(line, '#'); i >= 0 {
 			// Discard comments.
 			line = line[0:i]
 		}

src/net/ip.go

@@ -12,7 +12,7 @@
 
 package net
 
-import _ "unsafe" // for go:linkname
+import "internal/bytealg"
 
 // IP address lengths (bytes).
 const (
@@ -246,7 +246,7 @@ func (ip IP) Mask(mask IPMask) IP {
 	if len(mask) == IPv6len && len(ip) == IPv4len && allFF(mask[:12]) {
 		mask = mask[12:]
 	}
-	if len(mask) == IPv4len && len(ip) == IPv6len && bytesEqual(ip[:12], v4InV6Prefix) {
+	if len(mask) == IPv4len && len(ip) == IPv6len && bytealg.Equal(ip[:12], v4InV6Prefix) {
 		ip = ip[12:]
 	}
 	n := len(ip)
@@ -406,21 +406,17 @@ func (ip *IP) UnmarshalText(text []byte) error {
 // considered to be equal.
 func (ip IP) Equal(x IP) bool {
 	if len(ip) == len(x) {
-		return bytesEqual(ip, x)
+		return bytealg.Equal(ip, x)
 	}
 	if len(ip) == IPv4len && len(x) == IPv6len {
-		return bytesEqual(x[0:12], v4InV6Prefix) && bytesEqual(ip, x[12:])
+		return bytealg.Equal(x[0:12], v4InV6Prefix) && bytealg.Equal(ip, x[12:])
 	}
 	if len(ip) == IPv6len && len(x) == IPv4len {
-		return bytesEqual(ip[0:12], v4InV6Prefix) && bytesEqual(ip[12:], x)
+		return bytealg.Equal(ip[0:12], v4InV6Prefix) && bytealg.Equal(ip[12:], x)
 	}
 	return false
 }
 
-// bytes.Equal is implemented in runtime/asm_$goarch.s
-//go:linkname bytesEqual bytes.Equal
-func bytesEqual(x, y []byte) bool
-
 func (ip IP) matchAddrFamily(x IP) bool {
 	return ip.To4() != nil && x.To4() != nil || ip.To16() != nil && ip.To4() == nil && x.To16() != nil && x.To4() == nil
 }
@@ -711,7 +707,7 @@ func parseIPZone(s string) (IP, string) {
 // For example, ParseCIDR("192.0.2.1/24") returns the IP address
 // 192.0.2.1 and the network 192.0.2.0/24.
 func ParseCIDR(s string) (IP, *IPNet, error) {
-	i := byteIndex(s, '/')
+	i := bytealg.IndexByteString(s, '/')
 	if i < 0 {
 		return nil, nil, &ParseError{Type: "CIDR address", Text: s}
 	}

src/net/ipsock.go

@@ -6,6 +6,7 @@ package net
 
 import (
 	"context"
+	"internal/bytealg"
 	"sync"
 )
 
@@ -170,7 +171,7 @@ func SplitHostPort(hostport string) (host, port string, err error) {
 
 	if hostport[0] == '[' {
 		// Expect the first ']' just before the last ':'.
-		end := byteIndex(hostport, ']')
+		end := bytealg.IndexByteString(hostport, ']')
 		if end < 0 {
 			return addrErr(hostport, "missing ']' in address")
 		}
@@ -192,14 +193,14 @@ func SplitHostPort(hostport string) (host, port string, err error) {
 		j, k = 1, end+1 // there can't be a '[' resp. ']' before these positions
 	} else {
 		host = hostport[:i]
-		if byteIndex(host, ':') >= 0 {
+		if bytealg.IndexByteString(host, ':') >= 0 {
 			return addrErr(hostport, tooManyColons)
 		}
 	}
-	if byteIndex(hostport[j:], '[') >= 0 {
+	if bytealg.IndexByteString(hostport[j:], '[') >= 0 {
 		return addrErr(hostport, "unexpected '[' in address")
 	}
-	if byteIndex(hostport[k:], ']') >= 0 {
+	if bytealg.IndexByteString(hostport[k:], ']') >= 0 {
 		return addrErr(hostport, "unexpected ']' in address")
 	}
 
@@ -226,7 +227,7 @@ func splitHostZone(s string) (host, zone string) {
 func JoinHostPort(host, port string) string {
 	// We assume that host is a literal IPv6 address if host has
 	// colons.
-	if byteIndex(host, ':') >= 0 {
+	if bytealg.IndexByteString(host, ':') >= 0 {
 		return "[" + host + "]:" + port
 	}
 	return host + ":" + port

src/net/ipsock_plan9.go

@@ -6,6 +6,7 @@ package net
 
 import (
 	"context"
+	"internal/bytealg"
 	"os"
 	"syscall"
 )
@@ -49,7 +50,7 @@ func probe(filename, query string) bool {
 // parsePlan9Addr parses address of the form [ip!]port (e.g. 127.0.0.1!80).
 func parsePlan9Addr(s string) (ip IP, iport int, err error) {
 	addr := IPv4zero // address contains port only
-	i := byteIndex(s, '!')
+	i := bytealg.IndexByteString(s, '!')
 	if i >= 0 {
 		addr = ParseIP(s[:i])
 		if addr == nil {

src/net/lookup_plan9.go

@@ -7,6 +7,7 @@ package net
 import (
 	"context"
 	"errors"
+	"internal/bytealg"
 	"io"
 	"os"
 )
@@ -135,7 +136,7 @@ func lookupProtocol(ctx context.Context, name string) (proto int, err error) {
 		return 0, UnknownNetworkError(name)
 	}
 	s := f[1]
-	if n, _, ok := dtoi(s[byteIndex(s, '=')+1:]); ok {
+	if n, _, ok := dtoi(s[bytealg.IndexByteString(s, '=')+1:]); ok {
 		return n, nil
 	}
 	return 0, UnknownNetworkError(name)
@@ -158,7 +159,7 @@ loop:
 			continue
 		}
 		addr := f[1]
-		if i := byteIndex(addr, '!'); i >= 0 {
+		if i := bytealg.IndexByteString(addr, '!'); i >= 0 {
 			addr = addr[:i] // remove port
 		}
 		if ParseIP(addr) == nil {
@@ -210,7 +211,7 @@ func (*Resolver) lookupPort(ctx context.Context, network, service string) (port
 		return 0, unknownPortError
 	}
 	s := f[1]
-	if i := byteIndex(s, '!'); i >= 0 {
+	if i := bytealg.IndexByteString(s, '!'); i >= 0 {
 		s = s[i+1:] // remove address
 	}
 	if n, _, ok := dtoi(s); ok {
@@ -304,7 +305,7 @@ func (*Resolver) lookupTXT(ctx context.Context, name string) (txt []string, err
 		return
 	}
 	for _, line := range lines {
-		if i := byteIndex(line, '\t'); i >= 0 {
+		if i := bytealg.IndexByteString(line, '\t'); i >= 0 {
 			txt = append(txt, absDomainName([]byte(line[i+1:])))
 		}
 	}

src/net/lookup_unix.go

@@ -8,6 +8,7 @@ package net
 
 import (
 	"context"
+	"internal/bytealg"
 	"sync"
 	"syscall"
 
@@ -27,7 +28,7 @@ func readProtocols() {
 
 	for line, ok := file.readLine(); ok; line, ok = file.readLine() {
 		// tcp    6   TCP    # transmission control protocol
-		if i := byteIndex(line, '#'); i >= 0 {
+		if i := bytealg.IndexByteString(line, '#'); i >= 0 {
 			line = line[0:i]
 		}
 		f := getFields(line)

src/net/nss.go

@@ -8,6 +8,7 @@ package net
 
 import (
 	"errors"
+	"internal/bytealg"
 	"io"
 	"os"
 )
@@ -85,7 +86,7 @@ func parseNSSConf(r io.Reader) *nssConf {
 		if len(line) == 0 {
 			return nil
 		}
-		colon := bytesIndexByte(line, ':')
+		colon := bytealg.IndexByte(line, ':')
 		if colon == -1 {
 			return errors.New("no colon on line")
 		}
@@ -96,7 +97,7 @@ func parseNSSConf(r io.Reader) *nssConf {
 			if len(srcs) == 0 {
 				break
 			}
-			sp := bytesIndexByte(srcs, ' ')
+			sp := bytealg.IndexByte(srcs, ' ')
 			var src string
 			if sp == -1 {
 				src = string(srcs)
@@ -108,7 +109,7 @@ func parseNSSConf(r io.Reader) *nssConf {
 			var criteria []nssCriterion
 			// See if there's a criteria block in brackets.
 			if len(srcs) > 0 && srcs[0] == '[' {
-				bclose := bytesIndexByte(srcs, ']')
+				bclose := bytealg.IndexByte(srcs, ']')
 				if bclose == -1 {
 					return errors.New("unclosed criterion bracket")
 				}
@@ -143,7 +144,7 @@ func parseCriteria(x []byte) (c []nssCriterion, err error) {
 		if len(f) < 3 {
 			return errors.New("criterion too short")
 		}
-		eq := bytesIndexByte(f, '=')
+		eq := bytealg.IndexByte(f, '=')
 		if eq == -1 {
 			return errors.New("criterion lacks equal sign")
 		}

src/net/parse.go

@@ -8,10 +8,10 @@
 package net
 
 import (
+	"internal/bytealg"
 	"io"
 	"os"
 	"time"
-	_ "unsafe" // For go:linkname
 )
 
 type file struct {
@@ -80,17 +80,11 @@ func stat(name string) (mtime time.Time, size int64, err error) {
 	return st.ModTime(), st.Size(), nil
 }
 
-// byteIndex is strings.IndexByte. It returns the index of the
-// first instance of c in s, or -1 if c is not present in s.
-// strings.IndexByte is implemented in  runtime/asm_$GOARCH.s
-//go:linkname byteIndex strings.IndexByte
-func byteIndex(s string, c byte) int
-
 // Count occurrences in s of any bytes in t.
 func countAnyByte(s string, t string) int {
 	n := 0
 	for i := 0; i < len(s); i++ {
-		if byteIndex(t, s[i]) >= 0 {
+		if bytealg.IndexByteString(t, s[i]) >= 0 {
 			n++
 		}
 	}
@@ -103,7 +97,7 @@ func splitAtBytes(s string, t string) []string {
 	n := 0
 	last := 0
 	for i := 0; i < len(s); i++ {
-		if byteIndex(t, s[i]) >= 0 {
+		if bytealg.IndexByteString(t, s[i]) >= 0 {
 			if last < i {
 				a[n] = s[last:i]
 				n++
@@ -276,7 +270,7 @@ func isSpace(b byte) bool {
 // removeComment returns line, removing any '#' byte and any following
 // bytes.
 func removeComment(line []byte) []byte {
-	if i := bytesIndexByte(line, '#'); i != -1 {
+	if i := bytealg.IndexByte(line, '#'); i != -1 {
 		return line[:i]
 	}
 	return line
@@ -287,7 +281,7 @@ func removeComment(line []byte) []byte {
 // It returns the first non-nil error returned by fn.
 func foreachLine(x []byte, fn func(line []byte) error) error {
 	for len(x) > 0 {
-		nl := bytesIndexByte(x, '\n')
+		nl := bytealg.IndexByte(x, '\n')
 		if nl == -1 {
 			return fn(x)
 		}
@@ -305,7 +299,7 @@ func foreachLine(x []byte, fn func(line []byte) error) error {
 func foreachField(x []byte, fn func(field []byte) error) error {
 	x = trimSpace(x)
 	for len(x) > 0 {
-		sp := bytesIndexByte(x, ' ')
+		sp := bytealg.IndexByte(x, ' ')
 		if sp == -1 {
 			return fn(x)
 		}
@@ -319,12 +313,6 @@ func foreachField(x []byte, fn func(field []byte) error) error {
 	return nil
 }
 
-// bytesIndexByte is bytes.IndexByte. It returns the index of the
-// first instance of c in s, or -1 if c is not present in s.
-// bytes.IndexByte is implemented in  runtime/asm_$GOARCH.s
-//go:linkname bytesIndexByte bytes.IndexByte
-func bytesIndexByte(s []byte, c byte) int
-
 // stringsHasSuffix is strings.HasSuffix. It reports whether s ends in
 // suffix.
 func stringsHasSuffix(s, suffix string) bool {

src/net/port_unix.go

@@ -8,7 +8,10 @@
 
 package net
 
-import "sync"
+import (
+	"internal/bytealg"
+	"sync"
+)
 
 var onceReadServices sync.Once
 
@@ -21,7 +24,7 @@ func readServices() {
 
 	for line, ok := file.readLine(); ok; line, ok = file.readLine() {
 		// "http 80/tcp www www-http # World Wide Web HTTP"
-		if i := byteIndex(line, '#'); i >= 0 {
+		if i := bytealg.IndexByteString(line, '#'); i >= 0 {
 			line = line[:i]
 		}
 		f := getFields(line)

src/net/sockopt_posix.go

@@ -7,6 +7,7 @@
 package net
 
 import (
+	"internal/bytealg"
 	"runtime"
 	"syscall"
 )
@@ -94,7 +95,7 @@ func setIPv4MreqToInterface(mreq *syscall.IPMreq, ifi *Interface) error {
 		}
 	}
 done:
-	if bytesEqual(mreq.Multiaddr[:], IPv4zero.To4()) {
+	if bytealg.Equal(mreq.Multiaddr[:], IPv4zero.To4()) {
 		return errNoSuchMulticastInterface
 	}
 	return nil