Add benchmarks for for sparsely escaped and densely escaped strings.
Then speed up the sparse unescaping part heavily by using IndexByte and
copy to skip the parts containing no escaping very fast.

Unescaping densely escaped strings slower because of
the new function call overhead. But sparsely encoded strings are seen
more often in the utf8 enabled web.

We win part of the speed back by looking up entityName differently.

	benchmark                  old ns/op    new ns/op    delta
	BenchmarkEscape                31680        31396   -0.90%
	BenchmarkEscapeNone             6507         6872   +5.61%
	BenchmarkUnescape              36481        48298  +32.39%
	BenchmarkUnescapeNone            332          325   -2.11%
	BenchmarkUnescapeSparse         8836         3221  -63.55%
	BenchmarkUnescapeDense         30639        32224   +5.17%

Change-Id: If606cb01897a40eefe35ba98f2ff23bb25251606
Reviewed-on: https://go-review.googlesource.com/10172Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The current implementations of MarshalJSON and MarshalText use
time.Format which returns a string (converted from a byte slice),
only to convert it back to a byte slice.

Avoid the conversion (and thus an allocation) by directly appending
the formatted time to a preallocated byte slice, using the new
AppendFormat function, introduced in golang.org/cl/1760.

This reduces the allocations done in Marshal[Text|JSON] by 50%.

benchmark                old ns/op     new ns/op     delta
BenchmarkMarshalJSON     626           507           -19.01%
BenchmarkMarshalText     598           511           -14.55%

benchmark                old allocs     new allocs     delta
BenchmarkMarshalJSON     2              1              -50.00%
BenchmarkMarshalText     2              1              -50.00%

benchmark                old bytes     new bytes     delta
BenchmarkMarshalJSON     96            48            -50.00%
BenchmarkMarshalText     96            48            -50.00%

Fixes #11025

Change-Id: I468f78d075a6ecc1cdc839df7fb407fbc6ff2e70
Reviewed-on: https://go-review.googlesource.com/10555Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Safer, more readable, shorter.

Change-Id: I5cf1f438e20a3df45fc43cc5c870a533f7c524bf
Reviewed-on: https://go-review.googlesource.com/10517Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Currently an expression like

var v = 0 >> 1000

is rejected by gc with a "stupid shift" error, while gotype
compiles it successfully.

As suggested by gri on the issue tracker, allow an rsh right
operand to be any valid uint value.

Fixes #11328

Change-Id: I6ccb3b7f842338d91fd26ae37dd4fa279d7fc440
Reviewed-on: https://go-review.googlesource.com/13777Reviewed-by: Robert Griesemer <gri@golang.org>

This updates the big package used by the compiler to match the
public big package which contains some updates and bug fixes.
Obtained by running vendor.bash in the internal/big directory.
No manual changes.

Change-Id: I299aecc6599d4a745a721ce48def32449640dbb2
Reviewed-on: https://go-review.googlesource.com/13815Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #12231.

Change-Id: I1f07c444623cd864667e21b2fee534eacdc193bb
Reviewed-on: https://go-review.googlesource.com/13814Reviewed-by: Ian Lance Taylor <iant@golang.org>

When there is no browser available on the system,
we should print the URL instead of failing.

Change-Id: I4a2b099e17609394273eff150062c285d76bbac1
Reviewed-on: https://go-review.googlesource.com/13774Reviewed-by: Dmitry Vyukov <dvyukov@google.com>

Even though the umul/uquo functions expect two valid, finite big.Floats
arguments, SetString was calling them with possibly Inf values, which
resulted in bogus return values.

Replace umul and udiv calls with Mul and Quo calls to fix this. Also,
fix two wrong tests.

See relevant issue on issue tracker for a detailed explanation.

Fixes #11341

Change-Id: Ie35222763a57a2d712a5f5f7baec75cab8189a53
Reviewed-on: https://go-review.googlesource.com/13778Reviewed-by: Robert Griesemer <gri@golang.org>

This is not a functional change.

Also:
- minor cleanups, better comments
- uniform spelling of noun "zeros" (per OED)

Fixes #11277.

Change-Id: I1726f358ce15907bd2410f646b02cf8b11b919cd
Reviewed-on: https://go-review.googlesource.com/11267Reviewed-by: Alan Donovan <adonovan@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>

I cannot find where it's being used.

This addresses a duplicate symbol issue encountered in golang/go#9327.

Change-Id: I8efda45a006ad3e19423748210c78bd5831215e0
Reviewed-on: https://go-review.googlesource.com/13615Reviewed-by: Ian Lance Taylor <iant@golang.org>

CL 9184 changed the runtime and syscall packages to link Solaris binaries
directly instead of using dlopen/dlsym but did not remove the unused (and
now broken) references to dlopen, dlclose, and dlsym.

Fixes #11923

Change-Id: I36345ce5e7b371bd601b7d48af000f4ccacd62c0
Reviewed-on: https://go-review.googlesource.com/13410Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>

Change-Id: I5310cef72e714b22bcf2ae9e6fd85dbb7e8a15a2
Reviewed-on: https://go-review.googlesource.com/13787Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Could go in 1.5, although not critical.
See also #12107

Change-Id: I7f1608b58581d21df4db58f0db654fef79e33a90
Reviewed-on: https://go-review.googlesource.com/13481Reviewed-by: Dave Cheney <dave@cheney.net>

R=1.6

Fixes #11669.

Change-Id: Id39e5401e991e46f014eb16b747f5d9b7b55b46a
Reviewed-on: https://go-review.googlesource.com/12937Reviewed-by: Alan Donovan <adonovan@google.com>

R=1.6

Fixes #11347.

Change-Id: Ic6b09f38682500ffcc8d1f96e58f7237a7528806
Reviewed-on: https://go-review.googlesource.com/12812Reviewed-by: Alan Donovan <adonovan@google.com>

R=1.6

Fixes #11667.
Fixes #11687.

Change-Id: I060db212e8e0ee35fdefb4d482398f8f71650b38
Reviewed-on: https://go-review.googlesource.com/12713Reviewed-by: Alan Donovan <adonovan@google.com>

Even Linux systems may not have _SC_GETPW_R_SIZE_MAX if using a
different libc than glibc (e.g. musl). Instead of having special-cases
for the BSDs, handle -1 correctly by always using a default buffer size.

Fixes #11319.

Change-Id: I8b1b260eb9830e6dbe7667f3f33d115ae4de4ce8
Reviewed-on: https://go-review.googlesource.com/13772Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #12244

Change-Id: Iee4e45d9bca0718c71fcc574bc51b2084c3dcb2a
Reviewed-on: https://go-review.googlesource.com/13783Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

Fixes #12229

Change-Id: I243e39f67748e6754fb7726b21b3afc1ff436771
Reviewed-on: https://go-review.googlesource.com/13780Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I1650124dd459dc401ccd73943ff7287b1b8c57e4
Reviewed-on: https://go-review.googlesource.com/13689Reviewed-by: Andrew Gerrand <adg@golang.org>

This makes sure the release page in the release will mention the release.

Fixes #12102.

Change-Id: I36befd7dba7ba9e70ae3335e21c8841179ac4eff
Reviewed-on: https://go-review.googlesource.com/13490Reviewed-by: Rob Pike <r@golang.org>

This is especially important for LookupAddr, which used to be pure Go
(lightweight, one goroutine per call) and without this CL is now
unconditionally cgo (heavy, one thread per call).

Fixes #12190.

Change-Id: I43436a942bc1838b024225893e156f280a1e80cf
Reviewed-on: https://go-review.googlesource.com/13698Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Go 1.4 and before have always returned DNS names with a trailing dot
for reverse lookups, as they do for basically all other routines returning
DNS names. Go 1.4 and before always implemented LookupAddr using
pure Go (not C library calls).

Go 1.5 added the ability to make a C library call to implement LookupAddr.
Unfortunately the C library call returns a DNS name without a trailing dot
(an unrooted name), meaning that if turn off cgo during make.bash then
you still get the rooted name but with cgo on you get an unrooted name.
The unrooted name is inconsistent with the pure Go implementation
and with all previous Go releases, so change it to a rooted name.

Fixes #12189.

Change-Id: I3d6b72277c121fe085ea6af30e5fe8019fc490ad
Reviewed-on: https://go-review.googlesource.com/13697Reviewed-by: Rob Pike <r@golang.org>

Fixes #12191.

Change-Id: I5c7659ccb0566dad3613041d9e76be87ceacae61
Reviewed-on: https://go-review.googlesource.com/13700Reviewed-by: Rob Pike <r@golang.org>

Thanks to Nathan Youngman for spotting them.

Change-Id: I1856527af66a5d1965265ec3dcd639d3f6d74bcc
Reviewed-on: https://go-review.googlesource.com/13711Reviewed-by: Russ Cox <rsc@golang.org>

Saying "Power 64" was wrong for reasons I don't remember.
(Those reasons are why we stopped using GOARCH=power64.)

Change-Id: Ifaac78d5733bfc780df01b1a66da766af0b17726
Reviewed-on: https://go-review.googlesource.com/13675Reviewed-by: Rob Pike <r@golang.org>

Make clear that this list is the list of supported systems
for binary distributions, and that other systems may be
able to build the distribution from source, in addition
to using gccgo.

Drop freebsd/arm from the list on this page.
We have never issued a binary distribution for freebsd/arm,
and we're not going to start in Go 1.5, since we don't even
have a working builder for it.

Drop freebsd/386 from the list on the page,
because we are unable to build binary distributions, per adg.

I think the wording here should probably be revised further,
but not now.

Change-Id: Ib43b6b64f5c438bfb9aa4d3daa43393f1e33b71f
Reviewed-on: https://go-review.googlesource.com/13690Reviewed-by: Andrew Gerrand <adg@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

This was missed when we did the rename months ago
because cmd/vet did not live in the main tree.
Now vet's asmdecl checks will apply to ppc64 assembly too.

Change-Id: I687cba89fef702f29dd118de76a7ca1041c414f6
Reviewed-on: https://go-review.googlesource.com/13677Reviewed-by: Andrew Gerrand <adg@golang.org>

Change-Id: Iaeba7c55bbb9e11ac30f3b61369aa597acc30190
Reviewed-on: https://go-review.googlesource.com/13691Reviewed-by: Russ Cox <rsc@golang.org>

Update #11184 (linux/ppc64).
Filed #12178 (solaris) for Go 1.6.

Change-Id: I9e3a456aaccb49590ad4e14b53ddfefca5b0801c
Reviewed-on: https://go-review.googlesource.com/13679Reviewed-by: Russ Cox <rsc@golang.org>

Tested by hand.
Only lines of code changing are protected by Fieldtrack_enabled > 0,
which is never true in standard Go distributions.

Fixes #12171.

Change-Id: I963b9997dac10829db8ad4bfc97a7d6bf14b55c6
Reviewed-on: https://go-review.googlesource.com/13676Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #12156.

Change-Id: I2d71163b98bcc770147eb9e78dc551a9d0b5b817
Reviewed-on: https://go-review.googlesource.com/13674Reviewed-by: Ian Lance Taylor <iant@golang.org>

The text segment starts farther into the binary when using
external linking on the mac. Test and fix.

Fixes #12173.

Change-Id: I1f0c81814bf70cd9decfceac3022784f4608eeef
Reviewed-on: https://go-review.googlesource.com/13672Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #12154.

Change-Id: I1e6d1a3479a8a6fc8f53aebd18fb142506110809
Reviewed-on: https://go-review.googlesource.com/13673Reviewed-by: Rob Pike <r@golang.org>

Found in a Google program running under the race detector.
No test, but verified that this fixes the race with go run -race of:

	package main

	import (
	        "crypto/tls"
	        "fmt"
	        "net"
	        "net/http"
	        "net/http/httptest"
	)

	func main() {
	        for {
	                ts := httptest.NewTLSServer(http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {}))
	                conf := &tls.Config{} // non-nil
	                a, b := net.Pipe()
	                go func() {
	                        sconn := tls.Server(a, conf)
	                        sconn.Handshake()
	                }()
	                tr := &http.Transport{
	                        TLSClientConfig: conf,
	                }
	                req, _ := http.NewRequest("GET", ts.URL, nil)
	                _, err := tr.RoundTrip(req)
	                println(fmt.Sprint(err))
	                a.Close()
	                b.Close()
	                ts.Close()
	        }
	}

Also modified cmd/vet to report the copy-of-mutex bug statically
in CL 13646, and fixed two other instances in the code found by vet.
But vet could not have told us about cloneTLSConfig vs cloneTLSClientConfig.

Confirmed that original report is also fixed by this.

Fixes #12099.

Change-Id: Iba0171549e01852a5ec3438c25a1951c98524dec
Reviewed-on: https://go-review.googlesource.com/13453Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Russ Cox <rsc@golang.org>

The SetOutput function has been there since Go 1.

Fixes #12162.

Change-Id: I66210374877581e42689f9943532141659a55ca7
Reviewed-on: https://go-review.googlesource.com/13637Reviewed-by: Rob Pike <r@golang.org>

Correct 'an' to 'on' in the comment above the Stable() function.

Change-Id: I714e38b2d3a79dfd539d5368967d1c6b519cb948
Reviewed-on: https://go-review.googlesource.com/13662Reviewed-by: Rob Pike <r@golang.org>

Fixes golang/go#12133

CL 13630 fixed the use of a stale reg[] array in the various arch
backends which was causing the check in clearfat to pass
unconditionally on arm64.

With this check fixed, arm64 now considers REGRT1 to always be in use
as it is part of the reserved register set, see arm64/gsubr.go.

However, ppc64 does not consider REGRT1 and REGRT2 to be part of its
reserved set, so its identical clearfat check passes.

This CL removes the Reginuse check inside clearfat as REGRT1 is
guarenteed always be free on arm64.

Change-Id: I4719150d3c3378fae155b863c474529df18d4c17
Reviewed-on: https://go-review.googlesource.com/13650Reviewed-by: Russ Cox <rsc@golang.org>

Use runtime.GOROOT instead of os.Getenv("GOROOT") to reference
trace-viewer html file. GOROOT env var is not necessary set,
runtime.GOROOT has a default value for such case.

Change-Id: I906a720f6822915bd9575756e6cbf6d622857c2b
Reviewed-on: https://go-review.googlesource.com/13593Reviewed-by: Russ Cox <rsc@golang.org>

Fixes #12144.

Change-Id: I112c6517371215c9797db8f1dffca0f3047c39e3
Reviewed-on: https://go-review.googlesource.com/13633Reviewed-by: Russ Cox <rsc@golang.org>