Godeps, vendor: convert dependency management to trash (#3198)

This commit converts the dependency management from Godeps to the vendor
folder, also switching the tool from godep to trash. Since the upstream tool
lacks a few features proposed via a few PRs, until those PRs are merged in
(if), use github.com/karalabe/trash.

You can update dependencies via trash --update.

All dependencies have been updated to their latest version.

Parts of the build system are reworked to drop old notions of Godeps and
invocation of the go vet command so that it doesn't run against the vendor
folder, as that will just blow up during vetting.

The conversion drops OpenCL (and hence GPU mining support) from ethash and our
codebase. The short reasoning is that there's noone to maintain and having
opencl libs in our deps messes up builds as go install ./... tries to build
them, failing with unsatisfied link errors for the C OpenCL deps.

golang.org/x/net/context is not vendored in. We expect it to be fetched by the
user (i.e. using go get). To keep ci.go builds reproducible the package is
"vendored" in build/_vendor.

vendor/golang.org/x/text/encoding/japanese/all.go

@@ -0,0 +1,12 @@
+// 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.
+
+package japanese
+
+import (
+	"golang.org/x/text/encoding"
+)
+
+// All is a list of all defined encodings in this package.
+var All = []encoding.Encoding{EUCJP, ISO2022JP, ShiftJIS}

vendor/golang.org/x/text/encoding/japanese/eucjp.go

@@ -0,0 +1,211 @@
+// Copyright 2013 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 japanese
+
+import (
+	"errors"
+	"unicode/utf8"
+
+	"golang.org/x/text/encoding"
+	"golang.org/x/text/encoding/internal"
+	"golang.org/x/text/encoding/internal/identifier"
+	"golang.org/x/text/transform"
+)
+
+// EUCJP is the EUC-JP encoding.
+var EUCJP encoding.Encoding = &eucJP
+
+var eucJP = internal.Encoding{
+	&internal.SimpleEncoding{eucJPDecoder{}, eucJPEncoder{}},
+	"EUC-JP",
+	identifier.EUCPkdFmtJapanese,
+}
+
+var errInvalidEUCJP = errors.New("japanese: invalid EUC-JP encoding")
+
+type eucJPDecoder struct{ transform.NopResetter }
+
+func (eucJPDecoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	r, size := rune(0), 0
+loop:
+	for ; nSrc < len(src); nSrc += size {
+		switch c0 := src[nSrc]; {
+		case c0 < utf8.RuneSelf:
+			r, size = rune(c0), 1
+
+		case c0 == 0x8e:
+			if nSrc+1 >= len(src) {
+				err = transform.ErrShortSrc
+				break loop
+			}
+			c1 := src[nSrc+1]
+			if c1 < 0xa1 || 0xdf < c1 {
+				err = errInvalidEUCJP
+				break loop
+			}
+			r, size = rune(c1)+(0xff61-0xa1), 2
+
+		case c0 == 0x8f:
+			if nSrc+2 >= len(src) {
+				err = transform.ErrShortSrc
+				break loop
+			}
+			c1 := src[nSrc+1]
+			if c1 < 0xa1 || 0xfe < c1 {
+				err = errInvalidEUCJP
+				break loop
+			}
+			c2 := src[nSrc+2]
+			if c2 < 0xa1 || 0xfe < c2 {
+				err = errInvalidEUCJP
+				break loop
+			}
+			r, size = '\ufffd', 3
+			if i := int(c1-0xa1)*94 + int(c2-0xa1); i < len(jis0212Decode) {
+				r = rune(jis0212Decode[i])
+				if r == 0 {
+					r = '\ufffd'
+				}
+			}
+
+		case 0xa1 <= c0 && c0 <= 0xfe:
+			if nSrc+1 >= len(src) {
+				err = transform.ErrShortSrc
+				break loop
+			}
+			c1 := src[nSrc+1]
+			if c1 < 0xa1 || 0xfe < c1 {
+				err = errInvalidEUCJP
+				break loop
+			}
+			r, size = '\ufffd', 2
+			if i := int(c0-0xa1)*94 + int(c1-0xa1); i < len(jis0208Decode) {
+				r = rune(jis0208Decode[i])
+				if r == 0 {
+					r = '\ufffd'
+				}
+			}
+
+		default:
+			err = errInvalidEUCJP
+			break loop
+		}
+
+		if nDst+utf8.RuneLen(r) > len(dst) {
+			err = transform.ErrShortDst
+			break loop
+		}
+		nDst += utf8.EncodeRune(dst[nDst:], r)
+	}
+	if atEOF && err == transform.ErrShortSrc {
+		err = errInvalidEUCJP
+	}
+	return nDst, nSrc, err
+}
+
+type eucJPEncoder struct{ transform.NopResetter }
+
+func (eucJPEncoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	r, size := rune(0), 0
+	for ; nSrc < len(src); nSrc += size {
+		r = rune(src[nSrc])
+
+		// Decode a 1-byte rune.
+		if r < utf8.RuneSelf {
+			size = 1
+
+		} else {
+			// Decode a multi-byte rune.
+			r, size = utf8.DecodeRune(src[nSrc:])
+			if size == 1 {
+				// All valid runes of size 1 (those below utf8.RuneSelf) were
+				// handled above. We have invalid UTF-8 or we haven't seen the
+				// full character yet.
+				if !atEOF && !utf8.FullRune(src[nSrc:]) {
+					err = transform.ErrShortSrc
+					break
+				}
+			}
+
+			// func init checks that the switch covers all tables.
+			switch {
+			case encode0Low <= r && r < encode0High:
+				if r = rune(encode0[r-encode0Low]); r != 0 {
+					goto write2or3
+				}
+			case encode1Low <= r && r < encode1High:
+				if r = rune(encode1[r-encode1Low]); r != 0 {
+					goto write2or3
+				}
+			case encode2Low <= r && r < encode2High:
+				if r = rune(encode2[r-encode2Low]); r != 0 {
+					goto write2or3
+				}
+			case encode3Low <= r && r < encode3High:
+				if r = rune(encode3[r-encode3Low]); r != 0 {
+					goto write2or3
+				}
+			case encode4Low <= r && r < encode4High:
+				if r = rune(encode4[r-encode4Low]); r != 0 {
+					goto write2or3
+				}
+			case encode5Low <= r && r < encode5High:
+				if 0xff61 <= r && r < 0xffa0 {
+					goto write2
+				}
+				if r = rune(encode5[r-encode5Low]); r != 0 {
+					goto write2or3
+				}
+			}
+			err = internal.ErrASCIIReplacement
+			break
+		}
+
+		if nDst >= len(dst) {
+			err = transform.ErrShortDst
+			break
+		}
+		dst[nDst] = uint8(r)
+		nDst++
+		continue
+
+	write2or3:
+		if r>>tableShift == jis0208 {
+			if nDst+2 > len(dst) {
+				err = transform.ErrShortDst
+				break
+			}
+		} else {
+			if nDst+3 > len(dst) {
+				err = transform.ErrShortDst
+				break
+			}
+			dst[nDst] = 0x8f
+			nDst++
+		}
+		dst[nDst+0] = 0xa1 + uint8(r>>codeShift)&codeMask
+		dst[nDst+1] = 0xa1 + uint8(r)&codeMask
+		nDst += 2
+		continue
+
+	write2:
+		if nDst+2 > len(dst) {
+			err = transform.ErrShortDst
+			break
+		}
+		dst[nDst+0] = 0x8e
+		dst[nDst+1] = uint8(r - (0xff61 - 0xa1))
+		nDst += 2
+		continue
+	}
+	return nDst, nSrc, err
+}
+
+func init() {
+	// Check that the hard-coded encode switch covers all tables.
+	if numEncodeTables != 6 {
+		panic("bad numEncodeTables")
+	}
+}

vendor/golang.org/x/text/encoding/japanese/iso2022jp.go

@@ -0,0 +1,296 @@
+// Copyright 2013 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 japanese
+
+import (
+	"errors"
+	"unicode/utf8"
+
+	"golang.org/x/text/encoding"
+	"golang.org/x/text/encoding/internal"
+	"golang.org/x/text/encoding/internal/identifier"
+	"golang.org/x/text/transform"
+)
+
+// ISO2022JP is the ISO-2022-JP encoding.
+var ISO2022JP encoding.Encoding = &iso2022JP
+
+var iso2022JP = internal.Encoding{
+	internal.FuncEncoding{iso2022JPNewDecoder, iso2022JPNewEncoder},
+	"ISO-2022-JP",
+	identifier.ISO2022JP,
+}
+
+func iso2022JPNewDecoder() transform.Transformer {
+	return new(iso2022JPDecoder)
+}
+
+func iso2022JPNewEncoder() transform.Transformer {
+	return new(iso2022JPEncoder)
+}
+
+var errInvalidISO2022JP = errors.New("japanese: invalid ISO-2022-JP encoding")
+
+const (
+	asciiState = iota
+	katakanaState
+	jis0208State
+	jis0212State
+)
+
+const asciiEsc = 0x1b
+
+type iso2022JPDecoder int
+
+func (d *iso2022JPDecoder) Reset() {
+	*d = asciiState
+}
+
+func (d *iso2022JPDecoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	r, size := rune(0), 0
+loop:
+	for ; nSrc < len(src); nSrc += size {
+		c0 := src[nSrc]
+		if c0 >= utf8.RuneSelf {
+			err = errInvalidISO2022JP
+			break loop
+		}
+
+		if c0 == asciiEsc {
+			if nSrc+2 >= len(src) {
+				err = transform.ErrShortSrc
+				break loop
+			}
+			size = 3
+			c1 := src[nSrc+1]
+			c2 := src[nSrc+2]
+			switch {
+			case c1 == '$' && (c2 == '@' || c2 == 'B'):
+				*d = jis0208State
+				continue
+			case c1 == '$' && c2 == '(':
+				if nSrc+3 >= len(src) {
+					err = transform.ErrShortSrc
+					break loop
+				}
+				size = 4
+				if src[nSrc]+3 == 'D' {
+					*d = jis0212State
+					continue
+				}
+			case c1 == '(' && (c2 == 'B' || c2 == 'J'):
+				*d = asciiState
+				continue
+			case c1 == '(' && c2 == 'I':
+				*d = katakanaState
+				continue
+			}
+			err = errInvalidISO2022JP
+			break loop
+		}
+
+		switch *d {
+		case asciiState:
+			r, size = rune(c0), 1
+
+		case katakanaState:
+			if c0 < 0x21 || 0x60 <= c0 {
+				err = errInvalidISO2022JP
+				break loop
+			}
+			r, size = rune(c0)+(0xff61-0x21), 1
+
+		default:
+			if c0 == 0x0a {
+				*d = asciiState
+				r, size = rune(c0), 1
+				break
+			}
+			if nSrc+1 >= len(src) {
+				err = transform.ErrShortSrc
+				break loop
+			}
+			size = 2
+			c1 := src[nSrc+1]
+			i := int(c0-0x21)*94 + int(c1-0x21)
+			if *d == jis0208State && i < len(jis0208Decode) {
+				r = rune(jis0208Decode[i])
+			} else if *d == jis0212State && i < len(jis0212Decode) {
+				r = rune(jis0212Decode[i])
+			} else {
+				r = '\ufffd'
+				break
+			}
+			if r == 0 {
+				r = '\ufffd'
+			}
+		}
+
+		if nDst+utf8.RuneLen(r) > len(dst) {
+			err = transform.ErrShortDst
+			break loop
+		}
+		nDst += utf8.EncodeRune(dst[nDst:], r)
+	}
+	if atEOF && err == transform.ErrShortSrc {
+		err = errInvalidISO2022JP
+	}
+	return nDst, nSrc, err
+}
+
+type iso2022JPEncoder int
+
+func (e *iso2022JPEncoder) Reset() {
+	*e = asciiState
+}
+
+func (e *iso2022JPEncoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	r, size := rune(0), 0
+	for ; nSrc < len(src); nSrc += size {
+		r = rune(src[nSrc])
+
+		// Decode a 1-byte rune.
+		if r < utf8.RuneSelf {
+			size = 1
+
+		} else {
+			// Decode a multi-byte rune.
+			r, size = utf8.DecodeRune(src[nSrc:])
+			if size == 1 {
+				// All valid runes of size 1 (those below utf8.RuneSelf) were
+				// handled above. We have invalid UTF-8 or we haven't seen the
+				// full character yet.
+				if !atEOF && !utf8.FullRune(src[nSrc:]) {
+					err = transform.ErrShortSrc
+					break
+				}
+			}
+
+			// func init checks that the switch covers all tables.
+			//
+			// http://encoding.spec.whatwg.org/#iso-2022-jp says that "the index jis0212
+			// is not used by the iso-2022-jp encoder due to lack of widespread support".
+			//
+			// TODO: do we have to special-case U+00A5 and U+203E, as per
+			// http://encoding.spec.whatwg.org/#iso-2022-jp
+			// Doing so would mean that "\u00a5" would not be preserved
+			// after an encode-decode round trip.
+			switch {
+			case encode0Low <= r && r < encode0High:
+				if r = rune(encode0[r-encode0Low]); r>>tableShift == jis0208 {
+					goto writeJIS
+				}
+			case encode1Low <= r && r < encode1High:
+				if r = rune(encode1[r-encode1Low]); r>>tableShift == jis0208 {
+					goto writeJIS
+				}
+			case encode2Low <= r && r < encode2High:
+				if r = rune(encode2[r-encode2Low]); r>>tableShift == jis0208 {
+					goto writeJIS
+				}
+			case encode3Low <= r && r < encode3High:
+				if r = rune(encode3[r-encode3Low]); r>>tableShift == jis0208 {
+					goto writeJIS
+				}
+			case encode4Low <= r && r < encode4High:
+				if r = rune(encode4[r-encode4Low]); r>>tableShift == jis0208 {
+					goto writeJIS
+				}
+			case encode5Low <= r && r < encode5High:
+				if 0xff61 <= r && r < 0xffa0 {
+					goto writeKatakana
+				}
+				if r = rune(encode5[r-encode5Low]); r>>tableShift == jis0208 {
+					goto writeJIS
+				}
+			}
+
+			// Switch back to ASCII state in case of error so that an ASCII
+			// replacement character can be written in the correct state.
+			if *e != asciiState {
+				if nDst+3 > len(dst) {
+					err = transform.ErrShortDst
+					break
+				}
+				*e = asciiState
+				dst[nDst+0] = asciiEsc
+				dst[nDst+1] = '('
+				dst[nDst+2] = 'B'
+				nDst += 3
+			}
+			err = internal.ErrASCIIReplacement
+			break
+		}
+
+		if *e != asciiState {
+			if nDst+4 > len(dst) {
+				err = transform.ErrShortDst
+				break
+			}
+			*e = asciiState
+			dst[nDst+0] = asciiEsc
+			dst[nDst+1] = '('
+			dst[nDst+2] = 'B'
+			nDst += 3
+		} else if nDst >= len(dst) {
+			err = transform.ErrShortDst
+			break
+		}
+		dst[nDst] = uint8(r)
+		nDst++
+		continue
+
+	writeJIS:
+		if *e != jis0208State {
+			if nDst+5 > len(dst) {
+				err = transform.ErrShortDst
+				break
+			}
+			*e = jis0208State
+			dst[nDst+0] = asciiEsc
+			dst[nDst+1] = '$'
+			dst[nDst+2] = 'B'
+			nDst += 3
+		} else if nDst+2 > len(dst) {
+			err = transform.ErrShortDst
+			break
+		}
+		dst[nDst+0] = 0x21 + uint8(r>>codeShift)&codeMask
+		dst[nDst+1] = 0x21 + uint8(r)&codeMask
+		nDst += 2
+		continue
+
+	writeKatakana:
+		if *e != katakanaState {
+			if nDst+4 > len(dst) {
+				err = transform.ErrShortDst
+				break
+			}
+			*e = katakanaState
+			dst[nDst+0] = asciiEsc
+			dst[nDst+1] = '('
+			dst[nDst+2] = 'I'
+			nDst += 3
+		} else if nDst >= len(dst) {
+			err = transform.ErrShortDst
+			break
+		}
+		dst[nDst] = uint8(r - (0xff61 - 0x21))
+		nDst++
+		continue
+	}
+	if atEOF && err == nil && *e != asciiState {
+		if nDst+3 > len(dst) {
+			err = transform.ErrShortDst
+		} else {
+			*e = asciiState
+			dst[nDst+0] = asciiEsc
+			dst[nDst+1] = '('
+			dst[nDst+2] = 'B'
+			nDst += 3
+		}
+	}
+	return nDst, nSrc, err
+}

vendor/golang.org/x/text/encoding/japanese/maketables.go

@@ -0,0 +1,161 @@
+// Copyright 2013 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.
+
+// +build ignore
+
+package main
+
+// This program generates tables.go:
+//	go run maketables.go | gofmt > tables.go
+
+// TODO: Emoji extensions?
+// http://www.unicode.org/faq/emoji_dingbats.html
+// http://www.unicode.org/Public/UNIDATA/EmojiSources.txt
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"net/http"
+	"sort"
+	"strings"
+)
+
+type entry struct {
+	jisCode, table int
+}
+
+func main() {
+	fmt.Printf("// generated by go run maketables.go; DO NOT EDIT\n\n")
+	fmt.Printf("// Package japanese provides Japanese encodings such as EUC-JP and Shift JIS.\n")
+	fmt.Printf(`package japanese // import "golang.org/x/text/encoding/japanese"` + "\n\n")
+
+	reverse := [65536]entry{}
+	for i := range reverse {
+		reverse[i].table = -1
+	}
+
+	tables := []struct {
+		url  string
+		name string
+	}{
+		{"http://encoding.spec.whatwg.org/index-jis0208.txt", "0208"},
+		{"http://encoding.spec.whatwg.org/index-jis0212.txt", "0212"},
+	}
+	for i, table := range tables {
+		res, err := http.Get(table.url)
+		if err != nil {
+			log.Fatalf("%q: Get: %v", table.url, err)
+		}
+		defer res.Body.Close()
+
+		mapping := [65536]uint16{}
+
+		scanner := bufio.NewScanner(res.Body)
+		for scanner.Scan() {
+			s := strings.TrimSpace(scanner.Text())
+			if s == "" || s[0] == '#' {
+				continue
+			}
+			x, y := 0, uint16(0)
+			if _, err := fmt.Sscanf(s, "%d 0x%x", &x, &y); err != nil {
+				log.Fatalf("%q: could not parse %q", table.url, s)
+			}
+			if x < 0 || 120*94 <= x {
+				log.Fatalf("%q: JIS code %d is out of range", table.url, x)
+			}
+			mapping[x] = y
+			if reverse[y].table == -1 {
+				reverse[y] = entry{jisCode: x, table: i}
+			}
+		}
+		if err := scanner.Err(); err != nil {
+			log.Fatalf("%q: scanner error: %v", table.url, err)
+		}
+
+		fmt.Printf("// jis%sDecode is the decoding table from JIS %s code to Unicode.\n// It is defined at %s\n",
+			table.name, table.name, table.url)
+		fmt.Printf("var jis%sDecode = [...]uint16{\n", table.name)
+		for i, m := range mapping {
+			if m != 0 {
+				fmt.Printf("\t%d: 0x%04X,\n", i, m)
+			}
+		}
+		fmt.Printf("}\n\n")
+	}
+
+	// Any run of at least separation continuous zero entries in the reverse map will
+	// be a separate encode table.
+	const separation = 1024
+
+	intervals := []interval(nil)
+	low, high := -1, -1
+	for i, v := range reverse {
+		if v.table == -1 {
+			continue
+		}
+		if low < 0 {
+			low = i
+		} else if i-high >= separation {
+			if high >= 0 {
+				intervals = append(intervals, interval{low, high})
+			}
+			low = i
+		}
+		high = i + 1
+	}
+	if high >= 0 {
+		intervals = append(intervals, interval{low, high})
+	}
+	sort.Sort(byDecreasingLength(intervals))
+
+	fmt.Printf("const (\n")
+	fmt.Printf("\tjis0208    = 1\n")
+	fmt.Printf("\tjis0212    = 2\n")
+	fmt.Printf("\tcodeMask   = 0x7f\n")
+	fmt.Printf("\tcodeShift  = 7\n")
+	fmt.Printf("\ttableShift = 14\n")
+	fmt.Printf(")\n\n")
+
+	fmt.Printf("const numEncodeTables = %d\n\n", len(intervals))
+	fmt.Printf("// encodeX are the encoding tables from Unicode to JIS code,\n")
+	fmt.Printf("// sorted by decreasing length.\n")
+	for i, v := range intervals {
+		fmt.Printf("// encode%d: %5d entries for runes in [%5d, %5d).\n", i, v.len(), v.low, v.high)
+	}
+	fmt.Printf("//\n")
+	fmt.Printf("// The high two bits of the value record whether the JIS code comes from the\n")
+	fmt.Printf("// JIS0208 table (high bits == 1) or the JIS0212 table (high bits == 2).\n")
+	fmt.Printf("// The low 14 bits are two 7-bit unsigned integers j1 and j2 that form the\n")
+	fmt.Printf("// JIS code (94*j1 + j2) within that table.\n")
+	fmt.Printf("\n")
+
+	for i, v := range intervals {
+		fmt.Printf("const encode%dLow, encode%dHigh = %d, %d\n\n", i, i, v.low, v.high)
+		fmt.Printf("var encode%d = [...]uint16{\n", i)
+		for j := v.low; j < v.high; j++ {
+			x := reverse[j]
+			if x.table == -1 {
+				continue
+			}
+			fmt.Printf("\t%d - %d: jis%s<<14 | 0x%02X<<7 | 0x%02X,\n",
+				j, v.low, tables[x.table].name, x.jisCode/94, x.jisCode%94)
+		}
+		fmt.Printf("}\n\n")
+	}
+}
+
+// interval is a half-open interval [low, high).
+type interval struct {
+	low, high int
+}
+
+func (i interval) len() int { return i.high - i.low }
+
+// byDecreasingLength sorts intervals by decreasing length.
+type byDecreasingLength []interval
+
+func (b byDecreasingLength) Len() int           { return len(b) }
+func (b byDecreasingLength) Less(i, j int) bool { return b[i].len() > b[j].len() }
+func (b byDecreasingLength) Swap(i, j int)      { b[i], b[j] = b[j], b[i] }

vendor/golang.org/x/text/encoding/japanese/shiftjis.go

@@ -0,0 +1,189 @@
+// Copyright 2013 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 japanese
+
+import (
+	"errors"
+	"unicode/utf8"
+
+	"golang.org/x/text/encoding"
+	"golang.org/x/text/encoding/internal"
+	"golang.org/x/text/encoding/internal/identifier"
+	"golang.org/x/text/transform"
+)
+
+// ShiftJIS is the Shift JIS encoding, also known as Code Page 932 and
+// Windows-31J.
+var ShiftJIS encoding.Encoding = &shiftJIS
+
+var shiftJIS = internal.Encoding{
+	&internal.SimpleEncoding{shiftJISDecoder{}, shiftJISEncoder{}},
+	"Shift JIS",
+	identifier.ShiftJIS,
+}
+
+var errInvalidShiftJIS = errors.New("japanese: invalid Shift JIS encoding")
+
+type shiftJISDecoder struct{ transform.NopResetter }
+
+func (shiftJISDecoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	r, size := rune(0), 0
+loop:
+	for ; nSrc < len(src); nSrc += size {
+		switch c0 := src[nSrc]; {
+		case c0 < utf8.RuneSelf:
+			r, size = rune(c0), 1
+
+		case 0xa1 <= c0 && c0 < 0xe0:
+			r, size = rune(c0)+(0xff61-0xa1), 1
+
+		case (0x81 <= c0 && c0 < 0xa0) || (0xe0 <= c0 && c0 < 0xfd):
+			if c0 <= 0x9f {
+				c0 -= 0x70
+			} else {
+				c0 -= 0xb0
+			}
+			c0 = 2*c0 - 0x21
+
+			if nSrc+1 >= len(src) {
+				err = transform.ErrShortSrc
+				break loop
+			}
+			c1 := src[nSrc+1]
+			switch {
+			case c1 < 0x40:
+				err = errInvalidShiftJIS
+				break loop
+			case c1 < 0x7f:
+				c0--
+				c1 -= 0x40
+			case c1 == 0x7f:
+				err = errInvalidShiftJIS
+				break loop
+			case c1 < 0x9f:
+				c0--
+				c1 -= 0x41
+			case c1 < 0xfd:
+				c1 -= 0x9f
+			default:
+				err = errInvalidShiftJIS
+				break loop
+			}
+			r, size = '\ufffd', 2
+			if i := int(c0)*94 + int(c1); i < len(jis0208Decode) {
+				r = rune(jis0208Decode[i])
+				if r == 0 {
+					r = '\ufffd'
+				}
+			}
+
+		default:
+			err = errInvalidShiftJIS
+			break loop
+		}
+
+		if nDst+utf8.RuneLen(r) > len(dst) {
+			err = transform.ErrShortDst
+			break loop
+		}
+		nDst += utf8.EncodeRune(dst[nDst:], r)
+	}
+	if atEOF && err == transform.ErrShortSrc {
+		err = errInvalidShiftJIS
+	}
+	return nDst, nSrc, err
+}
+
+type shiftJISEncoder struct{ transform.NopResetter }
+
+func (shiftJISEncoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	r, size := rune(0), 0
+loop:
+	for ; nSrc < len(src); nSrc += size {
+		r = rune(src[nSrc])
+
+		// Decode a 1-byte rune.
+		if r < utf8.RuneSelf {
+			size = 1
+
+		} else {
+			// Decode a multi-byte rune.
+			r, size = utf8.DecodeRune(src[nSrc:])
+			if size == 1 {
+				// All valid runes of size 1 (those below utf8.RuneSelf) were
+				// handled above. We have invalid UTF-8 or we haven't seen the
+				// full character yet.
+				if !atEOF && !utf8.FullRune(src[nSrc:]) {
+					err = transform.ErrShortSrc
+					break loop
+				}
+			}
+
+			// func init checks that the switch covers all tables.
+			switch {
+			case encode0Low <= r && r < encode0High:
+				if r = rune(encode0[r-encode0Low]); r>>tableShift == jis0208 {
+					goto write2
+				}
+			case encode1Low <= r && r < encode1High:
+				if r = rune(encode1[r-encode1Low]); r>>tableShift == jis0208 {
+					goto write2
+				}
+			case encode2Low <= r && r < encode2High:
+				if r = rune(encode2[r-encode2Low]); r>>tableShift == jis0208 {
+					goto write2
+				}
+			case encode3Low <= r && r < encode3High:
+				if r = rune(encode3[r-encode3Low]); r>>tableShift == jis0208 {
+					goto write2
+				}
+			case encode4Low <= r && r < encode4High:
+				if r = rune(encode4[r-encode4Low]); r>>tableShift == jis0208 {
+					goto write2
+				}
+			case encode5Low <= r && r < encode5High:
+				if 0xff61 <= r && r < 0xffa0 {
+					r -= 0xff61 - 0xa1
+					goto write1
+				}
+				if r = rune(encode5[r-encode5Low]); r>>tableShift == jis0208 {
+					goto write2
+				}
+			}
+			err = internal.ErrASCIIReplacement
+			break
+		}
+
+	write1:
+		if nDst >= len(dst) {
+			err = transform.ErrShortDst
+			break
+		}
+		dst[nDst] = uint8(r)
+		nDst++
+		continue
+
+	write2:
+		j1 := uint8(r>>codeShift) & codeMask
+		j2 := uint8(r) & codeMask
+		if nDst+2 > len(dst) {
+			err = transform.ErrShortDst
+			break loop
+		}
+		if j1 <= 61 {
+			dst[nDst+0] = 129 + j1/2
+		} else {
+			dst[nDst+0] = 193 + j1/2
+		}
+		if j1&1 == 0 {
+			dst[nDst+1] = j2 + j2/63 + 64
+		} else {
+			dst[nDst+1] = j2 + 159
+		}
+		nDst += 2
+		continue
+	}
+	return nDst, nSrc, err
+}