libgo: update to Go 1.11

    
    Reviewed-on: https://go-review.googlesource.com/136435

gotools/:
	* Makefile.am (mostlyclean-local): Run chmod on check-go-dir to
	make sure it is writable.
	(check-go-tools): Likewise.
	(check-vet): Copy internal/objabi to check-vet-dir.
	* Makefile.in: Rebuild.

From-SVN: r264546

11 files changed, 147 insertions, 333 deletions

diff --git a/libgo/go/bytes/buffer.go b/libgo/go/bytes/buffer.go
index dc9d5e9..a2eca2e 100644
--- a/libgo/go/bytes/buffer.go
+++ b/libgo/go/bytes/buffer.go
@@ -202,6 +202,7 @@ func (b *Buffer) ReadFrom(r io.Reader) (n int64, err error) {
 	b.lastRead = opInvalid
 	for {
 		i := b.grow(MinRead)
+		b.buf = b.buf[:i]
 		m, e := r.Read(b.buf[i:cap(b.buf)])
 		if m < 0 {
 			panic(errNegativeRead)
diff --git a/libgo/go/bytes/buffer_test.go b/libgo/go/bytes/buffer_test.go
index e4bbc12..acbe5ca 100644
--- a/libgo/go/bytes/buffer_test.go
+++ b/libgo/go/bytes/buffer_test.go
@@ -269,6 +269,39 @@ func TestReadFrom(t *testing.T) {
 	}
 }
 
+type panicReader struct{ panic bool }
+
+func (r panicReader) Read(p []byte) (int, error) {
+	if r.panic {
+		panic(nil)
+	}
+	return 0, io.EOF
+}
+
+// Make sure that an empty Buffer remains empty when
+// it is "grown" before a Read that panics
+func TestReadFromPanicReader(t *testing.T) {
+
+	// First verify non-panic behaviour
+	var buf Buffer
+	i, err := buf.ReadFrom(panicReader{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if i != 0 {
+		t.Fatalf("unexpected return from bytes.ReadFrom (1): got: %d, want %d", i, 0)
+	}
+	check(t, "TestReadFromPanicReader (1)", &buf, "")
+
+	// Confirm that when Reader panics, the emtpy buffer remains empty
+	var buf2 Buffer
+	defer func() {
+		recover()
+		check(t, "TestReadFromPanicReader (2)", &buf2, "")
+	}()
+	buf2.ReadFrom(panicReader{panic: true})
+}
+
 func TestReadFromNegativeReader(t *testing.T) {
 	var b Buffer
 	defer func() {
diff --git a/libgo/go/bytes/bytes.go b/libgo/go/bytes/bytes.go
index 9af177f..437a6e1 100644
--- a/libgo/go/bytes/bytes.go
+++ b/libgo/go/bytes/bytes.go
@@ -7,6 +7,7 @@
 package bytes
 
 import (
+	"internal/bytealg"
 	"unicode"
 	"unicode/utf8"
 )
@@ -46,12 +47,16 @@ func explode(s []byte, n int) [][]byte {
 	return a[0:na]
 }
 
-// countGeneric actually implements Count
-func countGeneric(s, sep []byte) int {
+// Count counts the number of non-overlapping instances of sep in s.
+// If sep is an empty slice, Count returns 1 + the number of UTF-8-encoded code points in s.
+func Count(s, sep []byte) int {
 	// special case
 	if len(sep) == 0 {
 		return utf8.RuneCount(s) + 1
 	}
+	if len(sep) == 1 {
+		return bytealg.Count(s, sep[0])
+	}
 	n := 0
 	for {
 		i := Index(s, sep)
@@ -800,9 +805,9 @@ func EqualFold(s, t []byte) bool {
 			tr, sr = sr, tr
 		}
 		// Fast check for ASCII.
-		if tr < utf8.RuneSelf && 'A' <= sr && sr <= 'Z' {
-			// ASCII, and sr is upper case.  tr must be lower case.
-			if tr == sr+'a'-'A' {
+		if tr < utf8.RuneSelf {
+			// ASCII only, sr/tr must be upper/lower case
+			if 'A' <= sr && sr <= 'Z' && tr == sr+'a'-'A' {
 				continue
 			}
 			return false
@@ -824,6 +829,92 @@ func EqualFold(s, t []byte) bool {
 	return len(s) == len(t)
 }
 
+// Index returns the index of the first instance of sep in s, or -1 if sep is not present in s.
+func Index(s, sep []byte) int {
+	n := len(sep)
+	switch {
+	case n == 0:
+		return 0
+	case n == 1:
+		return IndexByte(s, sep[0])
+	case n == len(s):
+		if Equal(sep, s) {
+			return 0
+		}
+		return -1
+	case n > len(s):
+		return -1
+	case n <= bytealg.MaxLen:
+		// Use brute force when s and sep both are small
+		if len(s) <= bytealg.MaxBruteForce {
+			return bytealg.Index(s, sep)
+		}
+		c := sep[0]
+		i := 0
+		t := s[:len(s)-n+1]
+		fails := 0
+		for i < len(t) {
+			if t[i] != c {
+				// IndexByte is faster than bytealg.Index, so use it as long as
+				// we're not getting lots of false positives.
+				o := IndexByte(t[i:], c)
+				if o < 0 {
+					return -1
+				}
+				i += o
+			}
+			if Equal(s[i:i+n], sep) {
+				return i
+			}
+			fails++
+			i++
+			// Switch to bytealg.Index when IndexByte produces too many false positives.
+			if fails > bytealg.Cutover(i) {
+				r := bytealg.Index(s[i:], sep)
+				if r >= 0 {
+					return r + i
+				}
+				return -1
+			}
+		}
+		return -1
+	}
+	c := sep[0]
+	i := 0
+	fails := 0
+	t := s[:len(s)-n+1]
+	for i < len(t) {
+		if t[i] != c {
+			o := IndexByte(t[i:], c)
+			if o < 0 {
+				break
+			}
+			i += o
+		}
+		if Equal(s[i:i+n], sep) {
+			return i
+		}
+		i++
+		fails++
+		if fails >= 4+i>>4 && i < len(t) {
+			// Give up on IndexByte, it isn't skipping ahead
+			// far enough to be better than Rabin-Karp.
+			// Experiments (using IndexPeriodic) suggest
+			// the cutover is about 16 byte skips.
+			// TODO: if large prefixes of sep are matching
+			// we should cutover at even larger average skips,
+			// because Equal becomes that much more expensive.
+			// This code does not take that effect into account.
+			j := indexRabinKarp(s[i:], sep)
+			if j < 0 {
+				return -1
+			}
+			return i + j
+		}
+	}
+	return -1
+}
+
 func indexRabinKarp(s, sep []byte) int {
 	// Rabin-Karp search
 	hashsep, pow := hashStr(sep)
diff --git a/libgo/go/bytes/bytes_amd64.go b/libgo/go/bytes/bytes_amd64.go
deleted file mode 100644
index 2fbbbb0..0000000
--- a/libgo/go/bytes/bytes_amd64.go
+++ /dev/null
@@ -1,90 +0,0 @@
-// Copyright 2016 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 bytes
-
-import "internal/cpu"
-
-//go:noescape
-
-// indexShortStr returns the index of the first instance of c in s, or -1 if c is not present in s.
-// indexShortStr requires 2 <= len(c) <= shortStringLen
-func indexShortStr(s, c []byte) int  // ../runtime/asm_amd64.s
-func countByte(s []byte, c byte) int // ../runtime/asm_amd64.s
-
-var shortStringLen int
-
-func init() {
-	if cpu.X86.HasAVX2 {
-		shortStringLen = 63
-	} else {
-		shortStringLen = 31
-	}
-}
-
-// Index returns the index of the first instance of sep in s, or -1 if sep is not present in s.
-func Index(s, sep []byte) int {
-	n := len(sep)
-	switch {
-	case n == 0:
-		return 0
-	case n == 1:
-		return IndexByte(s, sep[0])
-	case n == len(s):
-		if Equal(sep, s) {
-			return 0
-		}
-		return -1
-	case n > len(s):
-		return -1
-	case n <= shortStringLen:
-		// Use brute force when s and sep both are small
-		if len(s) <= 64 {
-			return indexShortStr(s, sep)
-		}
-		c := sep[0]
-		i := 0
-		t := s[:len(s)-n+1]
-		fails := 0
-		for i < len(t) {
-			if t[i] != c {
-				// IndexByte skips 16/32 bytes per iteration,
-				// so it's faster than indexShortStr.
-				o := IndexByte(t[i:], c)
-				if o < 0 {
-					return -1
-				}
-				i += o
-			}
-			if Equal(s[i:i+n], sep) {
-				return i
-			}
-			fails++
-			i++
-			// Switch to indexShortStr when IndexByte produces too many false positives.
-			// Too many means more that 1 error per 8 characters.
-			// Allow some errors in the beginning.
-			if fails > (i+16)/8 {
-				r := indexShortStr(s[i:], sep)
-				if r >= 0 {
-					return r + i
-				}
-				return -1
-			}
-		}
-		return -1
-	}
-	return indexRabinKarp(s, sep)
-}
-
-// Count counts the number of non-overlapping instances of sep in s.
-// If sep is an empty slice, Count returns 1 + the number of UTF-8-encoded code points in s.
-func Count(s, sep []byte) int {
-	if len(sep) == 1 && cpu.X86.HasPOPCNT {
-		return countByte(s, sep[0])
-	}
-	return countGeneric(s, sep)
-}
diff --git a/libgo/go/bytes/bytes_arm64.go b/libgo/go/bytes/bytes_arm64.go
deleted file mode 100644
index 1213b06..0000000
--- a/libgo/go/bytes/bytes_arm64.go
+++ /dev/null
@@ -1,70 +0,0 @@
-// Copyright 2017 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 bytes
-
-func countByte(s []byte, c byte) int // bytes_arm64.s
-
-// Index returns the index of the first instance of sep in s, or -1 if sep is not present in s.
-func Index(s, sep []byte) int {
-	n := len(sep)
-	switch {
-	case n == 0:
-		return 0
-	case n == 1:
-		return IndexByte(s, sep[0])
-	case n == len(s):
-		if Equal(sep, s) {
-			return 0
-		}
-		return -1
-	case n > len(s):
-		return -1
-	}
-	c := sep[0]
-	i := 0
-	fails := 0
-	t := s[:len(s)-n+1]
-	for i < len(t) {
-		if t[i] != c {
-			o := IndexByte(t[i:], c)
-			if o < 0 {
-				break
-			}
-			i += o
-		}
-		if Equal(s[i:i+n], sep) {
-			return i
-		}
-		i++
-		fails++
-		if fails >= 4+i>>4 && i < len(t) {
-			// Give up on IndexByte, it isn't skipping ahead
-			// far enough to be better than Rabin-Karp.
-			// Experiments (using IndexPeriodic) suggest
-			// the cutover is about 16 byte skips.
-			// TODO: if large prefixes of sep are matching
-			// we should cutover at even larger average skips,
-			// because Equal becomes that much more expensive.
-			// This code does not take that effect into account.
-			j := indexRabinKarp(s[i:], sep)
-			if j < 0 {
-				return -1
-			}
-			return i + j
-		}
-	}
-	return -1
-}
-
-// Count counts the number of non-overlapping instances of sep in s.
-// If sep is an empty slice, Count returns 1 + the number of UTF-8-encoded code points in s.
-func Count(s, sep []byte) int {
-	if len(sep) == 1 {
-		return countByte(s, sep[0])
-	}
-	return countGeneric(s, sep)
-}
diff --git a/libgo/go/bytes/bytes_decl.go b/libgo/go/bytes/bytes_decl.go
index df0614f..af0f8b1 100644
--- a/libgo/go/bytes/bytes_decl.go
+++ b/libgo/go/bytes/bytes_decl.go
@@ -6,19 +6,19 @@ package bytes
 
 //go:noescape
 
-// IndexByte returns the index of the first instance of c in s, or -1 if c is not present in s.
-func IndexByte(s []byte, c byte) int // ../runtime/asm_$GOARCH.s
+// IndexByte returns the index of the first instance of c in b, or -1 if c is not present in b.
+func IndexByte(b []byte, c byte) int // in internal/bytealg
 
 //go:noescape
 
 // Equal returns a boolean reporting whether a and b
 // are the same length and contain the same bytes.
 // A nil argument is equivalent to an empty slice.
-func Equal(a, b []byte) bool // ../runtime/asm_$GOARCH.s
+func Equal(a, b []byte) bool // in internal/bytealg
 
 //go:noescape
 
 // Compare returns an integer comparing two byte slices lexicographically.
 // The result will be 0 if a==b, -1 if a < b, and +1 if a > b.
 // A nil argument is equivalent to an empty slice.
-func Compare(a, b []byte) int // ../runtime/noasm.go or ../runtime/asm_{386,amd64}.s
+func Compare(a, b []byte) int // in internal/bytealg
diff --git a/libgo/go/bytes/bytes_generic.go b/libgo/go/bytes/bytes_generic.go
deleted file mode 100644
index b52d939..0000000
--- a/libgo/go/bytes/bytes_generic.go
+++ /dev/null
@@ -1,65 +0,0 @@
-// 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.
-
-// -build !amd64,!s390x,!arm64
-
-package bytes
-
-// Index returns the index of the first instance of sep in s, or -1 if sep is not present in s.
-func Index(s, sep []byte) int {
-	n := len(sep)
-	switch {
-	case n == 0:
-		return 0
-	case n == 1:
-		return IndexByte(s, sep[0])
-	case n == len(s):
-		if Equal(sep, s) {
-			return 0
-		}
-		return -1
-	case n > len(s):
-		return -1
-	}
-	c := sep[0]
-	i := 0
-	fails := 0
-	t := s[:len(s)-n+1]
-	for i < len(t) {
-		if t[i] != c {
-			o := IndexByte(t[i:], c)
-			if o < 0 {
-				break
-			}
-			i += o
-		}
-		if Equal(s[i:i+n], sep) {
-			return i
-		}
-		i++
-		fails++
-		if fails >= 4+i>>4 && i < len(t) {
-			// Give up on IndexByte, it isn't skipping ahead
-			// far enough to be better than Rabin-Karp.
-			// Experiments (using IndexPeriodic) suggest
-			// the cutover is about 16 byte skips.
-			// TODO: if large prefixes of sep are matching
-			// we should cutover at even larger average skips,
-			// because Equal becomes that much more expensive.
-			// This code does not take that effect into account.
-			j := indexRabinKarp(s[i:], sep)
-			if j < 0 {
-				return -1
-			}
-			return i + j
-		}
-	}
-	return -1
-}
-
-// Count counts the number of non-overlapping instances of sep in s.
-// If sep is an empty slice, Count returns 1 + the number of UTF-8-encoded code points in s.
-func Count(s, sep []byte) int {
-	return countGeneric(s, sep)
-}
diff --git a/libgo/go/bytes/bytes_s390x.go b/libgo/go/bytes/bytes_s390x.go
deleted file mode 100644
index 0c22848..0000000
--- a/libgo/go/bytes/bytes_s390x.go
+++ /dev/null
@@ -1,88 +0,0 @@
-// Copyright 2016 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 bytes
-
-//go:noescape
-
-// indexShortStr returns the index of the first instance of sep in s,
-// or -1 if sep is not present in s.
-// indexShortStr requires 2 <= len(sep) <= shortStringLen
-func indexShortStr(s, c []byte) int // ../runtime/asm_s390x.s
-
-// supportsVX reports whether the vector facility is available.
-// indexShortStr must not be called if the vector facility is not
-// available.
-func supportsVX() bool // ../runtime/asm_s390x.s
-
-var shortStringLen = -1
-
-func init() {
-	if supportsVX() {
-		shortStringLen = 64
-	}
-}
-
-// Index returns the index of the first instance of sep in s, or -1 if sep is not present in s.
-func Index(s, sep []byte) int {
-	n := len(sep)
-	switch {
-	case n == 0:
-		return 0
-	case n == 1:
-		return IndexByte(s, sep[0])
-	case n == len(s):
-		if Equal(sep, s) {
-			return 0
-		}
-		return -1
-	case n > len(s):
-		return -1
-	case n <= shortStringLen:
-		// Use brute force when s and sep both are small
-		if len(s) <= 64 {
-			return indexShortStr(s, sep)
-		}
-		c := sep[0]
-		i := 0
-		t := s[:len(s)-n+1]
-		fails := 0
-		for i < len(t) {
-			if t[i] != c {
-				// IndexByte skips 16/32 bytes per iteration,
-				// so it's faster than indexShortStr.
-				o := IndexByte(t[i:], c)
-				if o < 0 {
-					return -1
-				}
-				i += o
-			}
-			if Equal(s[i:i+n], sep) {
-				return i
-			}
-			fails++
-			i++
-			// Switch to indexShortStr when IndexByte produces too many false positives.
-			// Too many means more that 1 error per 8 characters.
-			// Allow some errors in the beginning.
-			if fails > (i+16)/8 {
-				r := indexShortStr(s[i:], sep)
-				if r >= 0 {
-					return r + i
-				}
-				return -1
-			}
-		}
-		return -1
-	}
-	return indexRabinKarp(s, sep)
-}
-
-// Count counts the number of non-overlapping instances of sep in s.
-// If sep is an empty slice, Count returns 1 + the number of UTF-8-encoded code points in s.
-func Count(s, sep []byte) int {
-	return countGeneric(s, sep)
-}
diff --git a/libgo/go/bytes/bytes_test.go b/libgo/go/bytes/bytes_test.go
index 23fce29..11c5ef9 100644
--- a/libgo/go/bytes/bytes_test.go
+++ b/libgo/go/bytes/bytes_test.go
@@ -415,10 +415,6 @@ func TestCountByte(t *testing.T) {
 			if p != j+1 {
 				t.Errorf("TestCountByte.Count(%q, 100) = %d", b[i:i+window], p)
 			}
-			pGeneric := CountGeneric(b[i:i+window], []byte{100})
-			if pGeneric != j+1 {
-				t.Errorf("TestCountByte.CountGeneric(%q, 100) = %d", b[i:i+window], p)
-			}
 		}
 	}
 
@@ -466,10 +462,6 @@ func TestCountByteNoMatch(t *testing.T) {
 			if p != 0 {
 				t.Errorf("TestCountByteNoMatch(%q, 0) = %d", b[i:i+window], p)
 			}
-			pGeneric := CountGeneric(b[i:i+window], []byte{0})
-			if pGeneric != 0 {
-				t.Errorf("TestCountByteNoMatch.CountGeneric(%q, 100) = %d", b[i:i+window], p)
-			}
 			for j := 0; j < window; j++ {
 				b[i+j] = byte(0)
 			}
diff --git a/libgo/go/bytes/compare_test.go b/libgo/go/bytes/compare_test.go
index 35088a1..3e33c27 100644
--- a/libgo/go/bytes/compare_test.go
+++ b/libgo/go/bytes/compare_test.go
@@ -6,6 +6,7 @@ package bytes_test
 
 import (
 	. "bytes"
+	"internal/testenv"
 	"testing"
 )
 
@@ -58,10 +59,20 @@ func TestCompareIdenticalSlice(t *testing.T) {
 }
 
 func TestCompareBytes(t *testing.T) {
-	n := 128
+	lengths := make([]int, 0) // lengths to test in ascending order
+	for i := 0; i <= 128; i++ {
+		lengths = append(lengths, i)
+	}
+	lengths = append(lengths, 256, 512, 1024, 1333, 4095, 4096, 4097)
+
+	if !testing.Short() || testenv.Builder() != "" {
+		lengths = append(lengths, 65535, 65536, 65537, 99999)
+	}
+
+	n := lengths[len(lengths)-1]
 	a := make([]byte, n+1)
 	b := make([]byte, n+1)
-	for len := 0; len < 128; len++ {
+	for _, len := range lengths {
 		// randomish but deterministic data. No 0 or 255.
 		for i := 0; i < len; i++ {
 			a[i] = byte(1 + 31*i%254)
diff --git a/libgo/go/bytes/export_test.go b/libgo/go/bytes/export_test.go
index 823c8b0..f61523e 100644
--- a/libgo/go/bytes/export_test.go
+++ b/libgo/go/bytes/export_test.go
@@ -7,4 +7,3 @@ package bytes
 // Export func for testing
 var IndexBytePortable = indexBytePortable
 var EqualPortable = equalPortable
-var CountGeneric = countGeneric