From 22b955cca564a9a3a5b8c9d9dd1e295b7943c128 Mon Sep 17 00:00:00 2001
From: Ian Lance Taylor <ian@gcc.gnu.org>
Date: Fri, 22 Jul 2016 18:15:38 +0000
Subject: libgo: update to go1.7rc3

    Reviewed-on: https://go-review.googlesource.com/25150

From-SVN: r238662
---
 libgo/go/regexp/backtrack.go            |   5 +-
 libgo/go/regexp/exec.go                 |  14 +----
 libgo/go/regexp/exec_test.go            |  83 ++++++++++++-------------
 libgo/go/regexp/onepass.go              |   6 +-
 libgo/go/regexp/onepass_test.go         |   4 +-
 libgo/go/regexp/regexp.go               | 103 +++++++++++++++++---------------
 libgo/go/regexp/syntax/compile.go       |   4 +-
 libgo/go/regexp/syntax/doc.go           |   4 +-
 libgo/go/regexp/syntax/parse.go         |  34 +++++------
 libgo/go/regexp/syntax/parse_test.go    |   2 +-
 libgo/go/regexp/syntax/prog.go          |   4 +-
 libgo/go/regexp/syntax/regexp.go        |   6 +-
 libgo/go/regexp/syntax/simplify.go      |   8 +--
 libgo/go/regexp/syntax/simplify_test.go |   6 +-
 14 files changed, 133 insertions(+), 150 deletions(-)

(limited to 'libgo/go/regexp')

diff --git a/libgo/go/regexp/backtrack.go b/libgo/go/regexp/backtrack.go
index fd95604..29f624b 100644
--- a/libgo/go/regexp/backtrack.go
+++ b/libgo/go/regexp/backtrack.go
@@ -36,7 +36,6 @@ type bitState struct {
 
 	end     int
 	cap     []int
-	input   input
 	jobs    []job
 	visited []uint32
 }
@@ -146,7 +145,7 @@ func (m *machine) tryBacktrack(b *bitState, i input, pc uint32, pos int) bool {
 		// Optimization: rather than push and pop,
 		// code that is going to Push and continue
 		// the loop simply updates ip, p, and arg
-		// and jumps to CheckAndLoop.  We have to
+		// and jumps to CheckAndLoop. We have to
 		// do the ShouldVisit check that Push
 		// would have, but we avoid the stack
 		// manipulation.
@@ -254,7 +253,6 @@ func (m *machine) tryBacktrack(b *bitState, i input, pc uint32, pos int) bool {
 
 			}
 			panic("bad arg in InstCapture")
-			continue
 
 		case syntax.InstEmptyWidth:
 			if syntax.EmptyOp(inst.Arg)&^i.context(pos) != 0 {
@@ -299,7 +297,6 @@ func (m *machine) tryBacktrack(b *bitState, i input, pc uint32, pos int) bool {
 			// Otherwise, continue on in hope of a longer match.
 			continue
 		}
-		panic("unreachable")
 	}
 
 	return m.matched
diff --git a/libgo/go/regexp/exec.go b/libgo/go/regexp/exec.go
index 5182720..4fd61b5 100644
--- a/libgo/go/regexp/exec.go
+++ b/libgo/go/regexp/exec.go
@@ -19,7 +19,7 @@ type queue struct {
 // A entry is an entry on a queue.
 // It holds both the instruction pc and the actual thread.
 // Some queue entries are just place holders so that the machine
-// knows it has considered that pc.  Such entries have t == nil.
+// knows it has considered that pc. Such entries have t == nil.
 type entry struct {
 	pc uint32
 	t  *thread
@@ -107,14 +107,6 @@ func (m *machine) alloc(i *syntax.Inst) *thread {
 	return t
 }
 
-// free returns t to the free pool.
-func (m *machine) free(t *thread) {
-	m.inputBytes.str = nil
-	m.inputString.str = ""
-	m.inputReader.r = nil
-	m.pool = append(m.pool, t)
-}
-
 // match runs the machine over the input starting at pos.
 // It reports whether a match was found.
 // If so, m.matchcap holds the submatch information.
@@ -192,7 +184,6 @@ func (m *machine) match(i input, pos int) bool {
 func (m *machine) clear(q *queue) {
 	for _, d := range q.dense {
 		if d.t != nil {
-			// m.free(d.t)
 			m.pool = append(m.pool, d.t)
 		}
 	}
@@ -213,7 +204,6 @@ func (m *machine) step(runq, nextq *queue, pos, nextPos int, c rune, nextCond sy
 			continue
 		}
 		if longest && m.matched && len(t.cap) > 0 && m.matchcap[0] < t.cap[0] {
-			// m.free(t)
 			m.pool = append(m.pool, t)
 			continue
 		}
@@ -232,7 +222,6 @@ func (m *machine) step(runq, nextq *queue, pos, nextPos int, c rune, nextCond sy
 				// First-match mode: cut off all lower-priority threads.
 				for _, d := range runq.dense[j+1:] {
 					if d.t != nil {
-						// m.free(d.t)
 						m.pool = append(m.pool, d.t)
 					}
 				}
@@ -253,7 +242,6 @@ func (m *machine) step(runq, nextq *queue, pos, nextPos int, c rune, nextCond sy
 			t = m.add(nextq, i.Out, nextPos, t.cap, nextCond, t)
 		}
 		if t != nil {
-			// m.free(t)
 			m.pool = append(m.pool, t)
 		}
 	}
diff --git a/libgo/go/regexp/exec_test.go b/libgo/go/regexp/exec_test.go
index 4872cb3..69f187e 100644
--- a/libgo/go/regexp/exec_test.go
+++ b/libgo/go/regexp/exec_test.go
@@ -22,7 +22,7 @@ import (
 // considered during RE2's exhaustive tests, which run all possible
 // regexps over a given set of atoms and operators, up to a given
 // complexity, over all possible strings over a given alphabet,
-// up to a given size.  Rather than try to link with RE2, we read a
+// up to a given size. Rather than try to link with RE2, we read a
 // log file containing the test cases and the expected matches.
 // The log file, re2-exhaustive.txt, is generated by running 'make log'
 // in the open source RE2 distribution https://github.com/google/re2/.
@@ -41,21 +41,21 @@ import (
 //	-;0-3 0-1 1-2 2-3
 //
 // The stanza begins by defining a set of strings, quoted
-// using Go double-quote syntax, one per line.  Then the
+// using Go double-quote syntax, one per line. Then the
 // regexps section gives a sequence of regexps to run on
-// the strings.  In the block that follows a regexp, each line
+// the strings. In the block that follows a regexp, each line
 // gives the semicolon-separated match results of running
 // the regexp on the corresponding string.
 // Each match result is either a single -, meaning no match, or a
 // space-separated sequence of pairs giving the match and
-// submatch indices.  An unmatched subexpression formats
+// submatch indices. An unmatched subexpression formats
 // its pair as a single - (not illustrated above).  For now
 // each regexp run produces two match results, one for a
 // ``full match'' that restricts the regexp to matching the entire
 // string or nothing, and one for a ``partial match'' that gives
 // the leftmost first match found in the string.
 //
-// Lines beginning with # are comments.  Lines beginning with
+// Lines beginning with # are comments. Lines beginning with
 // a capital letter are test names printed during RE2's test suite
 // and are echoed into t but otherwise ignored.
 //
@@ -155,9 +155,9 @@ func testRE2(t *testing.T, file string) {
 			if !isSingleBytes(text) && strings.Contains(re.String(), `\B`) {
 				// RE2's \B considers every byte position,
 				// so it sees 'not word boundary' in the
-				// middle of UTF-8 sequences.  This package
+				// middle of UTF-8 sequences. This package
 				// only considers the positions between runes,
-				// so it disagrees.  Skip those cases.
+				// so it disagrees. Skip those cases.
 				continue
 			}
 			res := strings.Split(line, ";")
@@ -409,7 +409,7 @@ Reading:
 		//     h	REG_MULTIREF		multiple digit backref
 		//     i	REG_ICASE		ignore case
 		//     j	REG_SPAN		. matches \n
-		//     k	REG_ESCAPE		\ to ecape [...] delimiter
+		//     k	REG_ESCAPE		\ to escape [...] delimiter
 		//     l	REG_LEFT		implicit ^...
 		//     m	REG_MINIMAL		minimal match
 		//     n	REG_NEWLINE		explicit \n match
@@ -658,47 +658,42 @@ func makeText(n int) []byte {
 	return text
 }
 
-func benchmark(b *testing.B, re string, n int) {
-	r := MustCompile(re)
-	t := makeText(n)
-	b.ResetTimer()
-	b.SetBytes(int64(n))
-	for i := 0; i < b.N; i++ {
-		if r.Match(t) {
-			b.Fatal("match!")
+func BenchmarkMatch(b *testing.B) {
+	for _, data := range benchData {
+		r := MustCompile(data.re)
+		for _, size := range benchSizes {
+			t := makeText(size.n)
+			b.Run(data.name+"/"+size.name, func(b *testing.B) {
+				b.SetBytes(int64(size.n))
+				for i := 0; i < b.N; i++ {
+					if r.Match(t) {
+						b.Fatal("match!")
+					}
+				}
+			})
 		}
 	}
 }
 
-const (
-	easy0  = "ABCDEFGHIJKLMNOPQRSTUVWXYZ$"
-	easy1  = "A[AB]B[BC]C[CD]D[DE]E[EF]F[FG]G[GH]H[HI]I[IJ]J$"
-	medium = "[XYZ]ABCDEFGHIJKLMNOPQRSTUVWXYZ$"
-	hard   = "[ -~]*ABCDEFGHIJKLMNOPQRSTUVWXYZ$"
-	parens = "([ -~])*(A)(B)(C)(D)(E)(F)(G)(H)(I)(J)(K)(L)(M)" +
-		"(N)(O)(P)(Q)(R)(S)(T)(U)(V)(W)(X)(Y)(Z)$"
-)
+var benchData = []struct{ name, re string }{
+	{"Easy0", "ABCDEFGHIJKLMNOPQRSTUVWXYZ$"},
+	{"Easy0i", "(?i)ABCDEFGHIJklmnopqrstuvwxyz$"},
+	{"Easy1", "A[AB]B[BC]C[CD]D[DE]E[EF]F[FG]G[GH]H[HI]I[IJ]J$"},
+	{"Medium", "[XYZ]ABCDEFGHIJKLMNOPQRSTUVWXYZ$"},
+	{"Hard", "[ -~]*ABCDEFGHIJKLMNOPQRSTUVWXYZ$"},
+	{"Hard1", "ABCD|CDEF|EFGH|GHIJ|IJKL|KLMN|MNOP|OPQR|QRST|STUV|UVWX|WXYZ"},
+}
 
-func BenchmarkMatchEasy0_32(b *testing.B)   { benchmark(b, easy0, 32<<0) }
-func BenchmarkMatchEasy0_1K(b *testing.B)   { benchmark(b, easy0, 1<<10) }
-func BenchmarkMatchEasy0_32K(b *testing.B)  { benchmark(b, easy0, 32<<10) }
-func BenchmarkMatchEasy0_1M(b *testing.B)   { benchmark(b, easy0, 1<<20) }
-func BenchmarkMatchEasy0_32M(b *testing.B)  { benchmark(b, easy0, 32<<20) }
-func BenchmarkMatchEasy1_32(b *testing.B)   { benchmark(b, easy1, 32<<0) }
-func BenchmarkMatchEasy1_1K(b *testing.B)   { benchmark(b, easy1, 1<<10) }
-func BenchmarkMatchEasy1_32K(b *testing.B)  { benchmark(b, easy1, 32<<10) }
-func BenchmarkMatchEasy1_1M(b *testing.B)   { benchmark(b, easy1, 1<<20) }
-func BenchmarkMatchEasy1_32M(b *testing.B)  { benchmark(b, easy1, 32<<20) }
-func BenchmarkMatchMedium_32(b *testing.B)  { benchmark(b, medium, 32<<0) }
-func BenchmarkMatchMedium_1K(b *testing.B)  { benchmark(b, medium, 1<<10) }
-func BenchmarkMatchMedium_32K(b *testing.B) { benchmark(b, medium, 32<<10) }
-func BenchmarkMatchMedium_1M(b *testing.B)  { benchmark(b, medium, 1<<20) }
-func BenchmarkMatchMedium_32M(b *testing.B) { benchmark(b, medium, 32<<20) }
-func BenchmarkMatchHard_32(b *testing.B)    { benchmark(b, hard, 32<<0) }
-func BenchmarkMatchHard_1K(b *testing.B)    { benchmark(b, hard, 1<<10) }
-func BenchmarkMatchHard_32K(b *testing.B)   { benchmark(b, hard, 32<<10) }
-func BenchmarkMatchHard_1M(b *testing.B)    { benchmark(b, hard, 1<<20) }
-func BenchmarkMatchHard_32M(b *testing.B)   { benchmark(b, hard, 32<<20) }
+var benchSizes = []struct {
+	name string
+	n    int
+}{
+	{"32", 32},
+	{"1K", 1 << 10},
+	{"32K", 32 << 10},
+	{"1M", 1 << 20},
+	{"32M", 32 << 20},
+}
 
 func TestLongest(t *testing.T) {
 	re, err := Compile(`a(|b)`)
diff --git a/libgo/go/regexp/onepass.go b/libgo/go/regexp/onepass.go
index 2ce3902..4991954 100644
--- a/libgo/go/regexp/onepass.go
+++ b/libgo/go/regexp/onepass.go
@@ -1,4 +1,4 @@
-// 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.
 
@@ -33,7 +33,7 @@ type onePassInst struct {
 }
 
 // OnePassPrefix returns a literal string that all matches for the
-// regexp must start with.  Complete is true if the prefix
+// regexp must start with. Complete is true if the prefix
 // is the entire match. Pc is the index of the last rune instruction
 // in the string. The OnePassPrefix skips over the mandatory
 // EmptyBeginText
@@ -450,7 +450,7 @@ func makeOnePass(p *onePassProg) *onePassProg {
 	for !instQueue.empty() {
 		visitQueue.clear()
 		pc := instQueue.next()
-		if !check(uint32(pc), m) {
+		if !check(pc, m) {
 			p = notOnePass
 			break
 		}
diff --git a/libgo/go/regexp/onepass_test.go b/libgo/go/regexp/onepass_test.go
index 8202ebe..f4e336c 100644
--- a/libgo/go/regexp/onepass_test.go
+++ b/libgo/go/regexp/onepass_test.go
@@ -1,4 +1,4 @@
-// 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.
 
@@ -133,8 +133,6 @@ func TestMergeRuneSet(t *testing.T) {
 	}
 }
 
-const noStr = `!`
-
 var onePass = &onePassProg{}
 
 var onePassTests = []struct {
diff --git a/libgo/go/regexp/regexp.go b/libgo/go/regexp/regexp.go
index d7d0edb..fe3db9f 100644
--- a/libgo/go/regexp/regexp.go
+++ b/libgo/go/regexp/regexp.go
@@ -22,14 +22,14 @@
 // All characters are UTF-8-encoded code points.
 //
 // There are 16 methods of Regexp that match a regular expression and identify
-// the matched text.  Their names are matched by this regular expression:
+// the matched text. Their names are matched by this regular expression:
 //
 //	Find(All)?(String)?(Submatch)?(Index)?
 //
 // If 'All' is present, the routine matches successive non-overlapping
-// matches of the entire expression.  Empty matches abutting a preceding
-// match are ignored.  The return value is a slice containing the successive
-// return values of the corresponding non-'All' routine.  These routines take
+// matches of the entire expression. Empty matches abutting a preceding
+// match are ignored. The return value is a slice containing the successive
+// return values of the corresponding non-'All' routine. These routines take
 // an extra integer argument, n; if n >= 0, the function returns at most n
 // matches/submatches.
 //
@@ -45,9 +45,9 @@
 //
 // If 'Index' is present, matches and submatches are identified by byte index
 // pairs within the input string: result[2*n:2*n+1] identifies the indexes of
-// the nth submatch.  The pair for n==0 identifies the match of the entire
-// expression.  If 'Index' is not present, the match is identified by the
-// text of the match/submatch.  If an index is negative, it means that
+// the nth submatch. The pair for n==0 identifies the match of the entire
+// expression. If 'Index' is not present, the match is identified by the
+// text of the match/submatch. If an index is negative, it means that
 // subexpression did not match any string in the input.
 //
 // There is also a subset of the methods that can be applied to text read
@@ -55,7 +55,7 @@
 //
 //	MatchReader, FindReaderIndex, FindReaderSubmatchIndex
 //
-// This set may grow.  Note that regular expression matches may need to
+// This set may grow. Note that regular expression matches may need to
 // examine text beyond the text returned by a match, so the methods that
 // match text from a RuneReader may read arbitrarily far into the input
 // before returning.
@@ -75,12 +75,18 @@ import (
 	"unicode/utf8"
 )
 
-var debug = false
-
 // Regexp is the representation of a compiled regular expression.
 // A Regexp is safe for concurrent use by multiple goroutines.
 type Regexp struct {
 	// read-only after Compile
+	regexpRO
+
+	// cache of machines for running regexp
+	mu      sync.Mutex
+	machine []*machine
+}
+
+type regexpRO struct {
 	expr           string         // as passed to Compile
 	prog           *syntax.Prog   // compiled program
 	onepass        *onePassProg   // onepass program or nil
@@ -93,10 +99,6 @@ type Regexp struct {
 	numSubexp      int
 	subexpNames    []string
 	longest        bool
-
-	// cache of machines for running regexp
-	mu      sync.Mutex
-	machine []*machine
 }
 
 // String returns the source text used to compile the regular expression.
@@ -109,10 +111,11 @@ func (re *Regexp) String() string {
 // When using a Regexp in multiple goroutines, giving each goroutine
 // its own copy helps to avoid lock contention.
 func (re *Regexp) Copy() *Regexp {
-	r := *re
-	r.mu = sync.Mutex{}
-	r.machine = nil
-	return &r
+	// It is not safe to copy Regexp by value
+	// since it contains a sync.Mutex.
+	return &Regexp{
+		regexpRO: re.regexpRO,
+	}
 }
 
 // Compile parses a regular expression and returns, if successful,
@@ -174,13 +177,15 @@ func compile(expr string, mode syntax.Flags, longest bool) (*Regexp, error) {
 		return nil, err
 	}
 	regexp := &Regexp{
-		expr:        expr,
-		prog:        prog,
-		onepass:     compileOnePass(prog),
-		numSubexp:   maxCap,
-		subexpNames: capNames,
-		cond:        prog.StartCond(),
-		longest:     longest,
+		regexpRO: regexpRO{
+			expr:        expr,
+			prog:        prog,
+			onepass:     compileOnePass(prog),
+			numSubexp:   maxCap,
+			subexpNames: capNames,
+			cond:        prog.StartCond(),
+			longest:     longest,
+		},
 	}
 	if regexp.onepass == notOnePass {
 		regexp.prefix, regexp.prefixComplete = prog.Prefix()
@@ -258,10 +263,10 @@ func (re *Regexp) NumSubexp() int {
 }
 
 // SubexpNames returns the names of the parenthesized subexpressions
-// in this Regexp.  The name for the first sub-expression is names[1],
+// in this Regexp. The name for the first sub-expression is names[1],
 // so that if m is a match slice, the name for m[i] is SubexpNames()[i].
 // Since the Regexp as a whole cannot be named, names[0] is always
-// the empty string.  The slice should not be modified.
+// the empty string. The slice should not be modified.
 func (re *Regexp) SubexpNames() []string {
 	return re.subexpNames
 }
@@ -394,7 +399,7 @@ func (i *inputReader) context(pos int) syntax.EmptyOp {
 }
 
 // LiteralPrefix returns a literal string that must begin any match
-// of the regular expression re.  It returns the boolean true if the
+// of the regular expression re. It returns the boolean true if the
 // literal string comprises the entire regular expression.
 func (re *Regexp) LiteralPrefix() (prefix string, complete bool) {
 	return re.prefix, re.prefixComplete
@@ -417,7 +422,7 @@ func (re *Regexp) Match(b []byte) bool {
 }
 
 // MatchReader checks whether a textual regular expression matches the text
-// read by the RuneReader.  More complicated queries need to use Compile and
+// read by the RuneReader. More complicated queries need to use Compile and
 // the full Regexp interface.
 func MatchReader(pattern string, r io.RuneReader) (matched bool, err error) {
 	re, err := Compile(pattern)
@@ -428,7 +433,7 @@ func MatchReader(pattern string, r io.RuneReader) (matched bool, err error) {
 }
 
 // MatchString checks whether a textual regular expression
-// matches a string.  More complicated queries need
+// matches a string. More complicated queries need
 // to use Compile and the full Regexp interface.
 func MatchString(pattern string, s string) (matched bool, err error) {
 	re, err := Compile(pattern)
@@ -439,7 +444,7 @@ func MatchString(pattern string, s string) (matched bool, err error) {
 }
 
 // Match checks whether a textual regular expression
-// matches a byte slice.  More complicated queries need
+// matches a byte slice. More complicated queries need
 // to use Compile and the full Regexp interface.
 func Match(pattern string, b []byte) (matched bool, err error) {
 	re, err := Compile(pattern)
@@ -450,11 +455,11 @@ func Match(pattern string, b []byte) (matched bool, err error) {
 }
 
 // ReplaceAllString returns a copy of src, replacing matches of the Regexp
-// with the replacement string repl.  Inside repl, $ signs are interpreted as
+// with the replacement string repl. Inside repl, $ signs are interpreted as
 // in Expand, so for instance $1 represents the text of the first submatch.
 func (re *Regexp) ReplaceAllString(src, repl string) string {
 	n := 2
-	if strings.Index(repl, "$") >= 0 {
+	if strings.Contains(repl, "$") {
 		n = 2 * (re.numSubexp + 1)
 	}
 	b := re.replaceAll(nil, src, n, func(dst []byte, match []int) []byte {
@@ -464,7 +469,7 @@ func (re *Regexp) ReplaceAllString(src, repl string) string {
 }
 
 // ReplaceAllLiteralString returns a copy of src, replacing matches of the Regexp
-// with the replacement string repl.  The replacement repl is substituted directly,
+// with the replacement string repl. The replacement repl is substituted directly,
 // without using Expand.
 func (re *Regexp) ReplaceAllLiteralString(src, repl string) string {
 	return string(re.replaceAll(nil, src, 2, func(dst []byte, match []int) []byte {
@@ -474,7 +479,7 @@ func (re *Regexp) ReplaceAllLiteralString(src, repl string) string {
 
 // ReplaceAllStringFunc returns a copy of src in which all matches of the
 // Regexp have been replaced by the return value of function repl applied
-// to the matched substring.  The replacement returned by repl is substituted
+// to the matched substring. The replacement returned by repl is substituted
 // directly, without using Expand.
 func (re *Regexp) ReplaceAllStringFunc(src string, repl func(string) string) string {
 	b := re.replaceAll(nil, src, 2, func(dst []byte, match []int) []byte {
@@ -530,7 +535,7 @@ func (re *Regexp) replaceAll(bsrc []byte, src string, nmatch int, repl func(dst
 			searchPos += width
 		} else if searchPos+1 > a[1] {
 			// This clause is only needed at the end of the input
-			// string.  In that case, DecodeRuneInString returns width=0.
+			// string. In that case, DecodeRuneInString returns width=0.
 			searchPos++
 		} else {
 			searchPos = a[1]
@@ -548,7 +553,7 @@ func (re *Regexp) replaceAll(bsrc []byte, src string, nmatch int, repl func(dst
 }
 
 // ReplaceAll returns a copy of src, replacing matches of the Regexp
-// with the replacement text repl.  Inside repl, $ signs are interpreted as
+// with the replacement text repl. Inside repl, $ signs are interpreted as
 // in Expand, so for instance $1 represents the text of the first submatch.
 func (re *Regexp) ReplaceAll(src, repl []byte) []byte {
 	n := 2
@@ -566,7 +571,7 @@ func (re *Regexp) ReplaceAll(src, repl []byte) []byte {
 }
 
 // ReplaceAllLiteral returns a copy of src, replacing matches of the Regexp
-// with the replacement bytes repl.  The replacement repl is substituted directly,
+// with the replacement bytes repl. The replacement repl is substituted directly,
 // without using Expand.
 func (re *Regexp) ReplaceAllLiteral(src, repl []byte) []byte {
 	return re.replaceAll(src, "", 2, func(dst []byte, match []int) []byte {
@@ -576,7 +581,7 @@ func (re *Regexp) ReplaceAllLiteral(src, repl []byte) []byte {
 
 // ReplaceAllFunc returns a copy of src in which all matches of the
 // Regexp have been replaced by the return value of function repl applied
-// to the matched byte slice.  The replacement returned by repl is substituted
+// to the matched byte slice. The replacement returned by repl is substituted
 // directly, without using Expand.
 func (re *Regexp) ReplaceAllFunc(src []byte, repl func([]byte) []byte) []byte {
 	return re.replaceAll(src, "", 2, func(dst []byte, match []int) []byte {
@@ -592,7 +597,7 @@ func special(b byte) bool {
 
 // QuoteMeta returns a string that quotes all regular expression metacharacters
 // inside the argument text; the returned string is a regular expression matching
-// the literal text.  For example, QuoteMeta(`[foo]`) returns `\[foo\]`.
+// the literal text. For example, QuoteMeta(`[foo]`) returns `\[foo\]`.
 func QuoteMeta(s string) string {
 	b := make([]byte, 2*len(s))
 
@@ -684,7 +689,7 @@ func (re *Regexp) Find(b []byte) []byte {
 }
 
 // FindIndex returns a two-element slice of integers defining the location of
-// the leftmost match in b of the regular expression.  The match itself is at
+// the leftmost match in b of the regular expression. The match itself is at
 // b[loc[0]:loc[1]].
 // A return value of nil indicates no match.
 func (re *Regexp) FindIndex(b []byte) (loc []int) {
@@ -696,9 +701,9 @@ func (re *Regexp) FindIndex(b []byte) (loc []int) {
 }
 
 // FindString returns a string holding the text of the leftmost match in s of the regular
-// expression.  If there is no match, the return value is an empty string,
+// expression. If there is no match, the return value is an empty string,
 // but it will also be empty if the regular expression successfully matches
-// an empty string.  Use FindStringIndex or FindStringSubmatch if it is
+// an empty string. Use FindStringIndex or FindStringSubmatch if it is
 // necessary to distinguish these cases.
 func (re *Regexp) FindString(s string) string {
 	a := re.doExecute(nil, nil, s, 0, 2)
@@ -709,7 +714,7 @@ func (re *Regexp) FindString(s string) string {
 }
 
 // FindStringIndex returns a two-element slice of integers defining the
-// location of the leftmost match in s of the regular expression.  The match
+// location of the leftmost match in s of the regular expression. The match
 // itself is at s[loc[0]:loc[1]].
 // A return value of nil indicates no match.
 func (re *Regexp) FindStringIndex(s string) (loc []int) {
@@ -722,7 +727,7 @@ func (re *Regexp) FindStringIndex(s string) (loc []int) {
 
 // FindReaderIndex returns a two-element slice of integers defining the
 // location of the leftmost match of the regular expression in text read from
-// the RuneReader.  The match text was found in the input stream at
+// the RuneReader. The match text was found in the input stream at
 // byte offset loc[0] through loc[1]-1.
 // A return value of nil indicates no match.
 func (re *Regexp) FindReaderIndex(r io.RuneReader) (loc []int) {
@@ -754,14 +759,14 @@ func (re *Regexp) FindSubmatch(b []byte) [][]byte {
 
 // Expand appends template to dst and returns the result; during the
 // append, Expand replaces variables in the template with corresponding
-// matches drawn from src.  The match slice should have been returned by
+// matches drawn from src. The match slice should have been returned by
 // FindSubmatchIndex.
 //
 // In the template, a variable is denoted by a substring of the form
 // $name or ${name}, where name is a non-empty sequence of letters,
-// digits, and underscores.  A purely numeric name like $1 refers to
+// digits, and underscores. A purely numeric name like $1 refers to
 // the submatch with the corresponding index; other names refer to
-// capturing parentheses named with the (?P<name>...) syntax.  A
+// capturing parentheses named with the (?P<name>...) syntax. A
 // reference to an out of range or unmatched index or a name that is not
 // present in the regular expression is replaced with an empty slice.
 //
@@ -920,7 +925,7 @@ func (re *Regexp) FindStringSubmatchIndex(s string) []int {
 // FindReaderSubmatchIndex returns a slice holding the index pairs
 // identifying the leftmost match of the regular expression of text read by
 // the RuneReader, and the matches, if any, of its subexpressions, as defined
-// by the 'Submatch' and 'Index' descriptions in the package comment.  A
+// by the 'Submatch' and 'Index' descriptions in the package comment. A
 // return value of nil indicates no match.
 func (re *Regexp) FindReaderSubmatchIndex(r io.RuneReader) []int {
 	return re.pad(re.doExecute(r, nil, "", 0, re.prog.NumCap))
diff --git a/libgo/go/regexp/syntax/compile.go b/libgo/go/regexp/syntax/compile.go
index 95f6f15..83e53ba 100644
--- a/libgo/go/regexp/syntax/compile.go
+++ b/libgo/go/regexp/syntax/compile.go
@@ -8,11 +8,11 @@ import "unicode"
 
 // A patchList is a list of instruction pointers that need to be filled in (patched).
 // Because the pointers haven't been filled in yet, we can reuse their storage
-// to hold the list.  It's kind of sleazy, but works well in practice.
+// to hold the list. It's kind of sleazy, but works well in practice.
 // See http://swtch.com/~rsc/regexp/regexp1.html for inspiration.
 //
 // These aren't really pointers: they're integers, so we can reinterpret them
-// this way without using package unsafe.  A value l denotes
+// this way without using package unsafe. A value l denotes
 // p.inst[l>>1].Out (l&1==0) or .Arg (l&1==1).
 // l == 0 denotes the empty list, okay because we start every program
 // with a fail instruction, so we'll never want to point at its output link.
diff --git a/libgo/go/regexp/syntax/doc.go b/libgo/go/regexp/syntax/doc.go
index e5e71f1..efc0b43 100644
--- a/libgo/go/regexp/syntax/doc.go
+++ b/libgo/go/regexp/syntax/doc.go
@@ -1,4 +1,4 @@
-// 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.
 
@@ -66,7 +66,7 @@ Grouping:
 
 Empty strings:
   ^              at beginning of text or line (flag m=true)
-  $              at end of text (like \z not \Z) or line (flag m=true)
+  $              at end of text (like \z not Perl's \Z) or line (flag m=true)
   \A             at beginning of text
   \b             at ASCII word boundary (\w on one side and \W, \A, or \z on the other)
   \B             not at ASCII word boundary
diff --git a/libgo/go/regexp/syntax/parse.go b/libgo/go/regexp/syntax/parse.go
index f38bbf6..7b8be55 100644
--- a/libgo/go/regexp/syntax/parse.go
+++ b/libgo/go/regexp/syntax/parse.go
@@ -1,4 +1,4 @@
-// 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.
 
@@ -141,9 +141,9 @@ func (p *parser) push(re *Regexp) *Regexp {
 }
 
 // maybeConcat implements incremental concatenation
-// of literal runes into string nodes.  The parser calls this
+// of literal runes into string nodes. The parser calls this
 // before each push, so only the top fragment of the stack
-// might need processing.  Since this is called before a push,
+// might need processing. Since this is called before a push,
 // the topmost literal is no longer subject to operators like *
 // (Otherwise ab* would turn into (ab)*.)
 // If r >= 0 and there's a node left over, maybeConcat uses it
@@ -600,7 +600,7 @@ func (p *parser) leadingString(re *Regexp) ([]rune, Flags) {
 }
 
 // removeLeadingString removes the first n leading runes
-// from the beginning of re.  It returns the replacement for re.
+// from the beginning of re. It returns the replacement for re.
 func (p *parser) removeLeadingString(re *Regexp, n int) *Regexp {
 	if re.Op == OpConcat && len(re.Sub) > 0 {
 		// Removing a leading string in a concatenation
@@ -957,11 +957,11 @@ func (p *parser) parsePerlFlags(s string) (rest string, err error) {
 	// Perl 5.10 gave in and implemented the Python version too,
 	// but they claim that the last two are the preferred forms.
 	// PCRE and languages based on it (specifically, PHP and Ruby)
-	// support all three as well.  EcmaScript 4 uses only the Python form.
+	// support all three as well. EcmaScript 4 uses only the Python form.
 	//
 	// In both the open source world (via Code Search) and the
 	// Google source tree, (?P<expr>name) is the dominant form,
-	// so that's the one we implement.  One is enough.
+	// so that's the one we implement. One is enough.
 	if len(t) > 4 && t[2] == 'P' && t[3] == '<' {
 		// Pull out name.
 		end := strings.IndexRune(t, '>')
@@ -989,7 +989,7 @@ func (p *parser) parsePerlFlags(s string) (rest string, err error) {
 		return t[end+1:], nil
 	}
 
-	// Non-capturing group.  Might also twiddle Perl flags.
+	// Non-capturing group. Might also twiddle Perl flags.
 	var c rune
 	t = t[2:] // skip (?
 	flags := p.flags
@@ -1257,7 +1257,7 @@ Switch:
 		if c < utf8.RuneSelf && !isalnum(c) {
 			// Escaped non-word characters are always themselves.
 			// PCRE is not quite so rigorous: it accepts things like
-			// \q, but we don't.  We once rejected \_, but too many
+			// \q, but we don't. We once rejected \_, but too many
 			// programs and people insist on using it, so allow \_.
 			return c, t, nil
 		}
@@ -1292,7 +1292,7 @@ Switch:
 		if c == '{' {
 			// Any number of digits in braces.
 			// Perl accepts any text at all; it ignores all text
-			// after the first non-hex digit.  We require only hex digits,
+			// after the first non-hex digit. We require only hex digits,
 			// and at least one.
 			nhex := 0
 			r = 0
@@ -1333,10 +1333,10 @@ Switch:
 		}
 		return x*16 + y, t, nil
 
-	// C escapes.  There is no case 'b', to avoid misparsing
+	// C escapes. There is no case 'b', to avoid misparsing
 	// the Perl word-boundary \b as the C backspace \b
-	// when in POSIX mode.  In Perl, /\b/ means word-boundary
-	// but /[\b]/ means backspace.  We don't support that.
+	// when in POSIX mode. In Perl, /\b/ means word-boundary
+	// but /[\b]/ means backspace. We don't support that.
 	// If you want a backspace, embed a literal backspace
 	// character or use \x08.
 	case 'a':
@@ -1377,7 +1377,7 @@ type charGroup struct {
 }
 
 // parsePerlClassEscape parses a leading Perl character class escape like \d
-// from the beginning of s.  If one is present, it appends the characters to r
+// from the beginning of s. If one is present, it appends the characters to r
 // and returns the new slice r and the remainder of the string.
 func (p *parser) parsePerlClassEscape(s string, r []rune) (out []rune, rest string) {
 	if p.flags&PerlX == 0 || len(s) < 2 || s[0] != '\\' {
@@ -1391,7 +1391,7 @@ func (p *parser) parsePerlClassEscape(s string, r []rune) (out []rune, rest stri
 }
 
 // parseNamedClass parses a leading POSIX named character class like [:alnum:]
-// from the beginning of s.  If one is present, it appends the characters to r
+// from the beginning of s. If one is present, it appends the characters to r
 // and returns the new slice r and the remainder of the string.
 func (p *parser) parseNamedClass(s string, r []rune) (out []rune, rest string, err error) {
 	if len(s) < 2 || s[0] != '[' || s[1] != ':' {
@@ -1454,7 +1454,7 @@ func unicodeTable(name string) (*unicode.RangeTable, *unicode.RangeTable) {
 }
 
 // parseUnicodeClass parses a leading Unicode character class like \p{Han}
-// from the beginning of s.  If one is present, it appends the characters to r
+// from the beginning of s. If one is present, it appends the characters to r
 // and returns the new slice r and the remainder of the string.
 func (p *parser) parseUnicodeClass(s string, r []rune) (out []rune, rest string, err error) {
 	if p.flags&UnicodeGroups == 0 || len(s) < 2 || s[0] != '\\' || s[1] != 'p' && s[1] != 'P' {
@@ -1692,7 +1692,7 @@ const (
 	// minimum and maximum runes involved in folding.
 	// checked during test.
 	minFold = 0x0041
-	maxFold = 0x118df
+	maxFold = 0x1e943
 )
 
 // appendFoldedRange returns the result of appending the range lo-hi
@@ -1718,7 +1718,7 @@ func appendFoldedRange(r []rune, lo, hi rune) []rune {
 		hi = maxFold
 	}
 
-	// Brute force.  Depend on appendRange to coalesce ranges on the fly.
+	// Brute force. Depend on appendRange to coalesce ranges on the fly.
 	for c := lo; c <= hi; c++ {
 		r = appendRange(r, c, c)
 		f := unicode.SimpleFold(c)
diff --git a/libgo/go/regexp/syntax/parse_test.go b/libgo/go/regexp/syntax/parse_test.go
index 5ca54bb..dd6529f 100644
--- a/libgo/go/regexp/syntax/parse_test.go
+++ b/libgo/go/regexp/syntax/parse_test.go
@@ -1,4 +1,4 @@
-// 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.
 
diff --git a/libgo/go/regexp/syntax/prog.go b/libgo/go/regexp/syntax/prog.go
index ae6db31..c32ae8d 100644
--- a/libgo/go/regexp/syntax/prog.go
+++ b/libgo/go/regexp/syntax/prog.go
@@ -144,7 +144,7 @@ func (i *Inst) op() InstOp {
 }
 
 // Prefix returns a literal string that all matches for the
-// regexp must start with.  Complete is true if the prefix
+// regexp must start with. Complete is true if the prefix
 // is the entire match.
 func (p *Prog) Prefix() (prefix string, complete bool) {
 	i, _ := p.skipNop(uint32(p.Start))
@@ -164,7 +164,7 @@ func (p *Prog) Prefix() (prefix string, complete bool) {
 }
 
 // StartCond returns the leading empty-width conditions that must
-// be true in any match.  It returns ^EmptyOp(0) if no matches are possible.
+// be true in any match. It returns ^EmptyOp(0) if no matches are possible.
 func (p *Prog) StartCond() EmptyOp {
 	var flag EmptyOp
 	pc := uint32(p.Start)
diff --git a/libgo/go/regexp/syntax/regexp.go b/libgo/go/regexp/syntax/regexp.go
index 75822cf..0fe9269 100644
--- a/libgo/go/regexp/syntax/regexp.go
+++ b/libgo/go/regexp/syntax/regexp.go
@@ -1,4 +1,4 @@
-// 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.
 
@@ -139,7 +139,7 @@ func writeRegexp(b *bytes.Buffer, re *Regexp) {
 		if len(re.Rune) == 0 {
 			b.WriteString(`^\x00-\x{10FFFF}`)
 		} else if re.Rune[0] == 0 && re.Rune[len(re.Rune)-1] == unicode.MaxRune {
-			// Contains 0 and MaxRune.  Probably a negated class.
+			// Contains 0 and MaxRune. Probably a negated class.
 			// Print the gaps.
 			b.WriteRune('^')
 			for i := 1; i < len(re.Rune)-1; i += 2 {
@@ -252,7 +252,7 @@ const meta = `\.+*?()|[]{}^$`
 
 func escape(b *bytes.Buffer, r rune, force bool) {
 	if unicode.IsPrint(r) {
-		if strings.IndexRune(meta, r) >= 0 || force {
+		if strings.ContainsRune(meta, r) || force {
 			b.WriteRune('\\')
 		}
 		b.WriteRune(r)
diff --git a/libgo/go/regexp/syntax/simplify.go b/libgo/go/regexp/syntax/simplify.go
index 7239041..e439325 100644
--- a/libgo/go/regexp/syntax/simplify.go
+++ b/libgo/go/regexp/syntax/simplify.go
@@ -1,4 +1,4 @@
-// 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.
 
@@ -8,7 +8,7 @@ package syntax
 // and with various other simplifications, such as rewriting /(?:a+)+/ to /a+/.
 // The resulting regexp will execute correctly but its string representation
 // will not produce the same parse tree, because capturing parentheses
-// may have been duplicated or removed.  For example, the simplified form
+// may have been duplicated or removed. For example, the simplified form
 // for /(x){1,2}/ is /(x)(x)?/ but both parentheses capture as $1.
 // The returned regexp may share structure with or be the original.
 func (re *Regexp) Simplify() *Regexp {
@@ -117,13 +117,13 @@ func (re *Regexp) Simplify() *Regexp {
 }
 
 // simplify1 implements Simplify for the unary OpStar,
-// OpPlus, and OpQuest operators.  It returns the simple regexp
+// OpPlus, and OpQuest operators. It returns the simple regexp
 // equivalent to
 //
 //	Regexp{Op: op, Flags: flags, Sub: {sub}}
 //
 // under the assumption that sub is already simple, and
-// without first allocating that structure.  If the regexp
+// without first allocating that structure. If the regexp
 // to be returned turns out to be equivalent to re, simplify1
 // returns re instead.
 //
diff --git a/libgo/go/regexp/syntax/simplify_test.go b/libgo/go/regexp/syntax/simplify_test.go
index 5d0f1de..9877db3 100644
--- a/libgo/go/regexp/syntax/simplify_test.go
+++ b/libgo/go/regexp/syntax/simplify_test.go
@@ -1,4 +1,4 @@
-// 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.
 
@@ -59,7 +59,7 @@ var simplifyTests = []struct {
 	{`a{0,1}`, `a?`},
 	// The next three are illegible because Simplify inserts (?:)
 	// parens instead of () parens to avoid creating extra
-	// captured subexpressions.  The comments show a version with fewer parens.
+	// captured subexpressions. The comments show a version with fewer parens.
 	{`(a){0,2}`, `(?:(a)(a)?)?`},                       //       (aa?)?
 	{`(a){0,4}`, `(?:(a)(?:(a)(?:(a)(a)?)?)?)?`},       //   (a(a(aa?)?)?)?
 	{`(a){2,6}`, `(a)(a)(?:(a)(?:(a)(?:(a)(a)?)?)?)?`}, // aa(a(a(aa?)?)?)?
@@ -117,7 +117,7 @@ var simplifyTests = []struct {
 	// Empty string as a regular expression.
 	// The empty string must be preserved inside parens in order
 	// to make submatches work right, so these tests are less
-	// interesting than they might otherwise be.  String inserts
+	// interesting than they might otherwise be. String inserts
 	// explicit (?:) in place of non-parenthesized empty strings,
 	// to make them easier to spot for other parsers.
 	{`(a|b|)`, `([a-b]|(?:))`},
-- 
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