Unroll s == "ab" to

len(s) == 2 && s[0] == 'a' && s[1] == 'b'

This generates faster and shorter code
by avoiding a runtime call.
Do something similar for !=.

The cutoff length is 6. This was chosen empirically
by examining binary sizes on arm, arm64, 386, and amd64
using the SSA backend.

For all architectures examined, 4, 5, and 6 were
the ideal cutoff, with identical binary sizes.

The distribution of constant string equality sizes
during 'go build -a std' is:

 40.81%   622 len 0
 14.11%   215 len 4
  9.45%   144 len 1
  7.81%   119 len 3
  7.48%   114 len 5
  5.12%    78 len 7
  4.13%    63 len 2
  3.54%    54 len 8
  2.69%    41 len 6
  1.18%    18 len 10
  0.85%    13 len 9
  0.66%    10 len 14
  0.59%     9 len 17
  0.46%     7 len 11
  0.26%     4 len 12
  0.20%     3 len 19
  0.13%     2 len 13
  0.13%     2 len 15
  0.13%     2 len 16
  0.07%     1 len 20
  0.07%     1 len 23
  0.07%     1 len 33
  0.07%     1 len 36

A cutoff of length 6 covers most of the cases.

Benchmarks on amd64 comparing a string to a constant of length 3:

Cmp/1same-8           4.78ns ± 6%  0.94ns ± 9%  -80.26%  (p=0.000 n=20+20)
Cmp/1diffbytes-8      6.43ns ± 6%  0.96ns ±11%  -85.13%  (p=0.000 n=20+20)
Cmp/3same-8           4.71ns ± 5%  1.28ns ± 5%  -72.90%  (p=0.000 n=20+20)
Cmp/3difffirstbyte-8  6.33ns ± 7%  1.27ns ± 7%  -79.90%  (p=0.000 n=20+20)
Cmp/3difflastbyte-8   6.34ns ± 8%  1.26ns ± 9%  -80.13%  (p=0.000 n=20+20)

The change to the prove test preserves the
existing intent of the test. When the string was
short, there was a new "proved in bounds" report
that referred to individual byte comparisons.

Change-Id: I593ac303b0d11f275672090c5c786ea0c6b8da13
Reviewed-on: https://go-review.googlesource.com/26758
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I14a7c08105e6bdcee04a5cc21d7932e9ca753384
Reviewed-on: https://go-review.googlesource.com/29138
Run-TryBot: Dave Cheney <dave@cheney.net>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fix conflict between CL 29213 and 29134.

Change-Id: Ie58bd7195893d7e634f1b257ee0bdd3250cd23c2
Reviewed-on: https://go-review.googlesource.com/29137
TryBot-Result: Gobot Gobot <gobot@golang.org>
Run-TryBot: Dave Cheney <dave@cheney.net>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

staticassign unwraps all CONVNOPs.
However, in the included test, we need the
CONVNOP for everything to typecheck.
Stop unwrapping unnecessarily.

The code we generate for this example is
suboptimal, but that's not new; see #17113.

Fixes #17111.

Change-Id: I29532787a074a6fe19a5cc53271eb9c84bf1b576
Reviewed-on: https://go-review.googlesource.com/29213
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

After the removal of the old backend many types are no longer referenced
outside internal/gc. Make these functions private so that tools like
honnef.co/go/unused can spot when they become dead code. In doing so
this CL identified several previously public helpers which are no longer
used, so removes them.

This should be the last of the public functions.

Change-Id: I7e9c4e72f86f391b428b9dddb6f0d516529706c3
Reviewed-on: https://go-review.googlesource.com/29134
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Instead of dumping information for the use
to copy/paste into the issue tracker,
open the issue tracker directly with a pre-filled
template.

Change-Id: I370d0063b609200497014ccda35244fa4314a662
Reviewed-on: https://go-review.googlesource.com/29210
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: If8d27cf1cd8d650ed0ba332448d3174d80b6b0ca
Reviewed-on: https://go-review.googlesource.com/29217
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: Ifa7a882b020f7b0c9602c28c3e5567e5d4c39e73
Reviewed-on: https://go-review.googlesource.com/29216
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>

Consistently use int16 for [ft]reg and int64 for [ft]offset.

Change-Id: I7d279bb6e4fb735105429234a949074bf1cefb29
Reviewed-on: https://go-review.googlesource.com/29215
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>

Change-Id: Ib05a8e149db8accdb1474703cd7b7004243d91d4
Reviewed-on: https://go-review.googlesource.com/29214
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>

These are no longer reachable as gins dispatches to ginscon for all
arch-specific instructions anyway.

Change-Id: I7f34883c16058308d8afa0f960dcf554af31bfe4
Reviewed-on: https://go-review.googlesource.com/29211Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

After the removal of the old backend many types are no longer referenced
outside internal/gc. Make these functions private so that tools like
honnef.co/go/unused can spot when they become dead code. In doing so
this CL identified several previously public helpers which are no longer
used, so removes them.

Change-Id: Idc2d485f493206de9d661bd3cb0ecb4684177b32
Reviewed-on: https://go-review.googlesource.com/29133
Run-TryBot: Dave Cheney <dave@cheney.net>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Remove unused functions spotted by honnef.co/go/unused.

Change-Id: Iabf3b201215ce21e420a60f4ef2679b36231eda7
Reviewed-on: https://go-review.googlesource.com/29132
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

It's not everything, but it is a good start.

I tried to make the CL delete only.  goimports forced
a few exceptions to that rule.

Update #16357

Change-Id: I041925cb2fe68bb7ae1617af862b22c48da649c1
Reviewed-on: https://go-review.googlesource.com/29168
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Martin Möhrmann <martisch@uos.de>

Get rid of BlockCheck. Josh goaded me into it, and I went
down a rabbithole making it happen.

NilCheck now panics if the pointer is nil and returns void, as before.
BlockCheck is gone, and NilCheck is no longer a Control value for
any block. It just exists (and deadcode knows not to throw it away).

I rewrote the nilcheckelim pass to handle this case.  In particular,
there can now be multiple NilCheck ops per block.

I moved all of the arch-dependent nil check elimination done as
part of ssaGenValue into its own proper pass, so we don't have to
duplicate that code for every architecture.

Making the arch-dependent nil check its own pass means I needed
to add a bunch of flags to the opcode table so I could write
the code without arch-dependent ops everywhere.

Change-Id: I419f891ac9b0de313033ff09115c374163416a9f
Reviewed-on: https://go-review.googlesource.com/29120
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

We will soon add dedicated builders for running vet/all.
Their name will end with "-vetall".
On those builders, run vet/all and nothing else.
On all other builders, including local all.bash,
don't run vet/all at all, because it is slow.

This will probably be refined more over time.

Change-Id: Ib1d0337adda84353931a325515c132068d4320cd
Reviewed-on: https://go-review.googlesource.com/28962
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Passes toolstash -cmp.

Fixes #16870.

Change-Id: I70dc3bbb3cd3031826e5a54b96ba1ea603c282d1
Reviewed-on: https://go-review.googlesource.com/27910
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

when not instrumenting:
- Intrinsify uses of slicebytetostringtmp within the runtime package
  in the ssa backend.
- Pass OARRAYBYTESTRTMP nodes to the compiler backends for lowering
  instead of generating calls to slicebytetostringtmp.

name                    old time/op  new time/op  delta
ConcatStringAndBytes-4  27.9ns ± 2%  24.7ns ± 2%  -11.52%  (p=0.000 n=43+43)

Fixes #17044

Change-Id: I51ce9c3b93284ce526edd0234f094e98580faf2d
Reviewed-on: https://go-review.googlesource.com/29017
Run-TryBot: Martin Möhrmann <martisch@uos.de>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Change-Id: I63e7fd7f62aa80e1252b0c5b6c472439aa66da73
Reviewed-on: https://go-review.googlesource.com/29169Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

It is unlikely that the value of UnixNano overflow in most
use cases. However, the max date of 2262 is also within the range
where it may be of concern to some users. Rather than have each
person recompute when this overflows to validate if its okay for
their use case, we just document it as within the years 1678 and
2262, for user's convenience.

Fixes #16977

Change-Id: I4988738c147f4a6d30f8b8735c3941b75113bb16
Reviewed-on: https://go-review.googlesource.com/28478Reviewed-by: Andrew Gerrand <adg@golang.org>

Prepared with gofmt -r.

Change-Id: Ib9f224cc20353acd9c5850dead1a2d32ca5427d3
Reviewed-on: https://go-review.googlesource.com/29165
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

No need to test so many sizes in race mode, especially for a package
which doesn't use goroutines.

Reduces test time from 2.5 minutes to 25 seconds.

Updates #17104

Change-Id: I7065b39273f82edece385c0d67b3f2d83d4934b8
Reviewed-on: https://go-review.googlesource.com/29163Reviewed-by: David Crawshaw <crawshaw@golang.org>

No coverage is gained by running the 1e6 versions of the test over the
1e4 versions. It just adds 140 seconds of race overhead time.

Updates #17104

Change-Id: I41408aedae34a8b1a148eebdda20269cdefffba3
Reviewed-on: https://go-review.googlesource.com/29159
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

Found by vet.

Change-Id: I9dbc6208ddbb5b407f4ddd20efbc166aac852cf7
Reviewed-on: https://go-review.googlesource.com/29162
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

CL 29110 brought the fix into the main tree.

Change-Id: I7bf02670d40f22d35c63e05173419fdee9f93462
Reviewed-on: https://go-review.googlesource.com/29161
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The standard sort swap method

func (t T) Swap(i, j int) {
  t[i], t[j] = t[j], t[i]
}

uses no stack space on architectures for which
FixedFrameSize == 0, currently 386 and amd64.

Nevertheless, we insert a stack check prologue.
This is because it contains a call to
runtime.panicindex.

However, for a few common runtime functions,
we know at compile time that they require
no arguments. Allow them to pass unnoticed.

Triggers for 380 functions during make.bash.
Cuts 4k off cmd/go.

encoding/binary benchmarks:

ReadSlice1000Int32s-8     9.49µs ± 3%    9.41µs ± 5%    ~     (p=0.075 n=29+27)
ReadStruct-8              1.50µs ± 3%    1.48µs ± 2%  -1.49%  (p=0.000 n=30+28)
ReadInts-8                 599ns ± 3%     600ns ± 3%    ~     (p=0.471 n=30+29)
WriteInts-8                836ns ± 4%     841ns ± 3%    ~     (p=0.371 n=30+29)
WriteSlice1000Int32s-8    8.84µs ± 3%    8.69µs ± 5%  -1.71%  (p=0.001 n=30+30)
PutUvarint32-8            29.6ns ± 1%    28.1ns ± 3%  -5.21%  (p=0.000 n=28+28)
PutUvarint64-8            82.6ns ± 5%    82.3ns ±10%  -0.43%  (p=0.014 n=27+30)

Swap assembly before:

"".T.Swap t=1 size=74 args=0x28 locals=0x0
	0x0000 00000 (swap.go:5)	TEXT	"".T.Swap(SB), $0-40
	0x0000 00000 (swap.go:5)	MOVQ	(TLS), CX
	0x0009 00009 (swap.go:5)	CMPQ	SP, 16(CX)
	0x000d 00013 (swap.go:5)	JLS	67
	0x000f 00015 (swap.go:5)	FUNCDATA	$0, gclocals·3cadd97b66f25a3a642be35e9362338f(SB)
	0x000f 00015 (swap.go:5)	FUNCDATA	$1, gclocals·69c1753bd5f81501d95132d08af04464(SB)
	0x000f 00015 (swap.go:5)	MOVQ	"".i+32(FP), AX
	0x0014 00020 (swap.go:5)	MOVQ	"".t+16(FP), CX
	0x0019 00025 (swap.go:5)	CMPQ	AX, CX
	0x001c 00028 (swap.go:5)	JCC	$0, 60
	0x001e 00030 (swap.go:5)	MOVQ	"".t+8(FP), DX
	0x0023 00035 (swap.go:5)	MOVBLZX	(DX)(AX*1), BX
	0x0027 00039 (swap.go:5)	MOVQ	"".j+40(FP), SI
	0x002c 00044 (swap.go:5)	CMPQ	SI, CX
	0x002f 00047 (swap.go:5)	JCC	$0, 60
	0x0031 00049 (swap.go:5)	MOVBLZX	(DX)(SI*1), CX
	0x0035 00053 (swap.go:5)	MOVB	CL, (DX)(AX*1)
	0x0038 00056 (swap.go:5)	MOVB	BL, (DX)(SI*1)
	0x003b 00059 (swap.go:5)	RET
	0x003c 00060 (swap.go:5)	PCDATA	$0, $1
	0x003c 00060 (swap.go:5)	CALL	runtime.panicindex(SB)
	0x0041 00065 (swap.go:5)	UNDEF
	0x0043 00067 (swap.go:5)	NOP
	0x0043 00067 (swap.go:5)	CALL	runtime.morestack_noctxt(SB)
	0x0048 00072 (swap.go:5)	JMP	0

Swap assembly after:

"".T.Swap t=1 size=52 args=0x28 locals=0x0
	0x0000 00000 (swap.go:5)	TEXT	"".T.Swap(SB), $0-40
	0x0000 00000 (swap.go:5)	FUNCDATA	$0, gclocals·3cadd97b66f25a3a642be35e9362338f(SB)
	0x0000 00000 (swap.go:5)	FUNCDATA	$1, gclocals·69c1753bd5f81501d95132d08af04464(SB)
	0x0000 00000 (swap.go:5)	MOVQ	"".i+32(FP), AX
	0x0005 00005 (swap.go:5)	MOVQ	"".t+16(FP), CX
	0x000a 00010 (swap.go:5)	CMPQ	AX, CX
	0x000d 00013 (swap.go:5)	JCC	$0, 45
	0x000f 00015 (swap.go:5)	MOVQ	"".t+8(FP), DX
	0x0014 00020 (swap.go:5)	MOVBLZX	(DX)(AX*1), BX
	0x0018 00024 (swap.go:5)	MOVQ	"".j+40(FP), SI
	0x001d 00029 (swap.go:5)	CMPQ	SI, CX
	0x0020 00032 (swap.go:5)	JCC	$0, 45
	0x0022 00034 (swap.go:5)	MOVBLZX	(DX)(SI*1), CX
	0x0026 00038 (swap.go:5)	MOVB	CL, (DX)(AX*1)
	0x0029 00041 (swap.go:5)	MOVB	BL, (DX)(SI*1)
	0x002c 00044 (swap.go:5)	RET
	0x002d 00045 (swap.go:5)	PCDATA	$0, $1
	0x002d 00045 (swap.go:5)	CALL	runtime.panicindex(SB)
	0x0032 00050 (swap.go:5)	UNDEF

Change-Id: I57dad14af8aaa5e6112deac407cfadc2bfaf1f54
Reviewed-on: https://go-review.googlesource.com/24814
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

cmd/cover, cmd/trace, and cmd/pprof all open browsers.
'go bug' will soon also open a browser.
It is time to unify the browser-handling code.

Change-Id: Iee6b443e21e938aeaaac366a1aefb1afbc7d9b2c
Reviewed-on: https://go-review.googlesource.com/29160
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Don't benchmark so many sizes during the race builder's benchmark run.

This package doesn't even use goroutines.

Cuts off 10 seconds.

Updates #17104

Change-Id: Ibb2c7272c18b9014a775949c656a5b930f197cd4
Reviewed-on: https://go-review.googlesource.com/29158Reviewed-by: David Crawshaw <crawshaw@golang.org>

Shave 6.5 minutes off the *-race build time.

The *-race builders run:

    go test -short -race -run=^$ -benchtime=.1s -cpu=4 $PKG

... for each package with benchmarks.

The point isn't to measure the speed of the packages, but rather to
see if there are any races. (which is why a benchtime of 0.1 seconds
is used)

But running in race mode makes things slower and our benchmarks aren't
all very fast to begin with.

The regexp benchmarks in race were taking over 6.5 minutes. With this
CL, it's now 8 seconds.

Updates #17104

Change-Id: I054528d09b1568d37aac9f9b515d6ed90a5cf5b0
Reviewed-on: https://go-review.googlesource.com/29156
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>

Rip out the code that allows SSA to be used conditionally.

No longer exists:
 ssa=0 flag
 GOSSAHASH
 GOSSAPKG
 SSATEST

GOSSAFUNC now only controls the printing of the IR/html.

Still need to rip out all of the old backend.  It should no longer be
callable after this CL.

Update #16357

Change-Id: Ib30cc18fba6ca52232c41689ba610b0a94aa74f5
Reviewed-on: https://go-review.googlesource.com/29155
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

It passed tests once, if anything's wrong, better to fail
sooner than later.

Change-Id: Ibb1c5db3f4c5535a4ff4681fd157db77082c5041
Reviewed-on: https://go-review.googlesource.com/28982
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

The go_test_bench:* tests run:

    go test -short -race -run=^$ -benchtime=.1s -cpu=4 $PKG

... on each discovered package with any tests. (The same set used for
the "go_test:*" tests)

That set was 168 packages:

$ go tool dist test -list | grep go_test: | wc -l
168

But only 76 of those have a "func Benchmark", and running each
"go_test_bench:" test and compiling it in race mode, just to do
nothing took 1-2 seconds each.

So stop doing that and filter out the useless packages earlier. Now:

$ go tool dist test -list -race | grep go_test_bench:  | wc -l
76

Should save 90-180 seconds. (or maybe 45 seconds for trybots, since
they're sharded)

Updates #17104

Change-Id: I08ccb072a0dc0454ea425540ee8e74b59f83b773
Reviewed-on: https://go-review.googlesource.com/29153
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

CL 26668 exposed #17065.
Skip the cgo race tests on darwin for now.

Updates #17065

Change-Id: I0ad0ce2ff1af6d515b8ce6184ddeabc49806950f
Reviewed-on: https://go-review.googlesource.com/29077
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The change corrects the values of the largest float32 value (f1) and the
value of the halfway point between f1 and the next, overflow value (f2).

Fixes #17012

Change-Id: Idaf9997b69d61fafbffdb980d751c9857732e14d
Reviewed-on: https://go-review.googlesource.com/29171Reviewed-by: Robert Griesemer <gri@golang.org>

For #17068

Change-Id: I4e3ab166f08100292b779b651a9acfbfb44a55cd
Reviewed-on: https://go-review.googlesource.com/29119
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This gets -buildmode=pie -ldflags=-linkmode=internal working on
Ubuntu 16.04.

Fixes #17068

Change-Id: Ice5036199005fb528cc58279a7f057170dc6b73d
Reviewed-on: https://go-review.googlesource.com/29118
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #16681

Change-Id: I6ff7ec81fe48ab06be3aae5b7ff92e9dc70960c3
Reviewed-on: https://go-review.googlesource.com/26990
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>

Updates #16360.

Adds examples for:
+ Chmod
+ Chtimes
+ FileMode

Change-Id: I1b61ee0392fa3774593a7f36aaf0fa1e484c778b
Reviewed-on: https://go-review.googlesource.com/28963
Run-TryBot: Andrew Gerrand <adg@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>

While you could argue the previous wording technically said that -1 is
an acceptable way to indicate "unknown" on the client, it could be read
as ambiguous. Now it's clear that both 0 and -1 mean unknown.

Change-Id: I3bc5a3fd5afd1999e487296ec121eb548415e6b0
Reviewed-on: https://go-review.googlesource.com/29130Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Created by running 'go generate'.

That made debugging fun today.

Change-Id: I9ffe00877851f2b198275220ad6058b9005daa72
Reviewed-on: https://go-review.googlesource.com/29117Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>