Some Linux kernels apparently have a sysctl that prohibits
nonprivileged processes from creating user namespaces.  If we see a
failure for that reason, skip the test.

Fixes #11261.

Change-Id: I82dfcaf475eea4eaa387941373ce7165df4848ad
Reviewed-on: https://go-review.googlesource.com/11269Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>

nacl is really giving a hard time. avoid all external dependencies in the test.
Worked with trybots, failed in the build. No explanation, but this should fix it.

TBR=rsc

Change-Id: Icb644286dbce88f17ee3d96ad90efba34a80a92d
Reviewed-on: https://go-review.googlesource.com/11291Reviewed-by: Rob Pike <r@golang.org>

Refactor main a bit to make it possible to run tests without an exec every time.
(Makes a huge difference in run time.)

Add a silver test. Not quite golden, since it looks for pieces rather than the
full output, and also includes tests for what should not appear.

Fixes #10920.

Change-Id: I6a4951cc14e61763379754a10b0cc3484d30c267
Reviewed-on: https://go-review.googlesource.com/11272Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Rob Pike <r@golang.org>

This sometime worries new contributors.
Hopefully mentioning it here will help.

Fixes #11300.

Change-Id: Ica7f10d749731704ac6a2c39c7dcba389996011e
Reviewed-on: https://go-review.googlesource.com/11236Reviewed-by: Ian Lance Taylor <iant@golang.org>

All of the heavy-lifting was done by minux@, with his external-linking support
for darwin/arm64: golang.org/cl/8781

Change-Id: I7c9fbc19246f418c065c92fb2c13c00026ff0f82
Reviewed-on: https://go-review.googlesource.com/11127
Run-TryBot: Srdjan Petrovic <spetrovic@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: Ia13d1fa450e88e278b81048b99686395ca474c99
Reviewed-on: https://go-review.googlesource.com/11259Reviewed-by: Russ Cox <rsc@golang.org>

Fixes #11284.

Change-Id: I4ecc4e4cd3c1b3467b43e4ba9666ea6db5fb61a5
Reviewed-on: https://go-review.googlesource.com/11268Reviewed-by: Alan Donovan <adonovan@google.com>

Change-Id: I42cfdb389282478ce0e29436464f2048ed087429
Reviewed-on: https://go-review.googlesource.com/11290Reviewed-by: Rob Pike <r@golang.org>

When GO15VENDOREXPERIMENT=1 is in the environment,
this CL changes the resolution of import paths according to
the Go 1.5 vendor proposal:

	If there is a source directory d/vendor, then,
	when compiling a source file within the subtree rooted at d,
	import "p" is interpreted as import "d/vendor/p" if that exists.

	When there are multiple possible resolutions,
	the most specific (longest) path wins.

	The short form must always be used: no import path can
	contain “/vendor/” explicitly.

	Import comments are ignored in vendored packages.

The goal of these changes is to allow authors to vendor (copy) external
packages into their source trees without any modifications to the code.
This functionality has been achieved in tools like godep, nut, and gb by
requiring GOPATH manipulation. This alternate directory-based approach
eliminates the need for GOPATH manipulation and in keeping with the
go command's use of directory layout-based configuration.

The flag allows experimentation with these vendoring semantics once
Go 1.5 is released, without forcing them on by default. If the experiment
is deemed a success, the flag will default to true in Go 1.6 and then be
removed in Go 1.7.

For more details, see the original proposal by Keith Rarick at
https://groups.google.com/d/msg/golang-dev/74zjMON9glU/dGhnoi2IMzsJ.

Change-Id: I2c6527e777d14ac6dc43c53e4b3ff24f3279216e
Reviewed-on: https://go-review.googlesource.com/10923Reviewed-by: Andrew Gerrand <adg@golang.org>

The -importmap option takes an argument of the form old=new
and specifies that import "old" should be interpreted as if it said
import "new". The option may be repeated to specify multiple mappings.

This option is here to support the go command's new -vendor flag.

Change-Id: I31b4ed4249b549982a720bf61bb230462b33c59b
Reviewed-on: https://go-review.googlesource.com/10922Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Currently its possible for the garbage collector to observe
uninitialized memory or stale heap bitmap bits on weakly ordered
architectures such as ARM and PPC. On such architectures, the stores
that zero newly allocated memory and initialize its heap bitmap may
move after a store in user code that makes the allocated object
observable by the garbage collector.

To fix this, add a "publication barrier" (also known as an "export
barrier") before returning from mallocgc. This is a store/store
barrier that ensures any write done by user code that makes the
returned object observable to the garbage collector will be ordered
after the initialization performed by mallocgc. No barrier is
necessary on the reading side because of the data dependency between
loading the pointer and loading the contents of the object.

Fixes one of the issues raised in #9984.

Change-Id: Ia3d96ad9c5fc7f4d342f5e05ec0ceae700cd17c8
Reviewed-on: https://go-review.googlesource.com/11083Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Martin Capitanio <capnm9@gmail.com>
Reviewed-by: Russ Cox <rsc@golang.org>

These tests were broken by https://go-review.googlesource.com/#/c/11227/
which fixed the LZW encoder to reject invalid input.

For TestNoPalette, the LZW encoder with a litWidth of 2 now rejects an
input byte of 128, so we change 128 to 3, as 3 <= (1<<2 - 1).

For TestPixelOutsidePaletteRange, the LZW encoder similarly rejects an
input byte of 255. Prior to golang.org/cl/11227, the encoder (again with
a litWidth of 2) accepted the 255 input byte, but masked it with (1<<2 -
1), so that the 255 test case was effectively the same as the 3 test
case. After that LZW CL, the 255 input byte is simply invalid, so we
remove it as a test case. The test still tests pixels outside of the
palette range, since 3 >= the length of the global palette, which is 2.

Change-Id: I50be9623ace016740e34801549c15f83671103eb
Reviewed-on: https://go-review.googlesource.com/11273Reviewed-by: David Symonds <dsymonds@golang.org>

Change-Id: I129d70304ae4e4694d9217826b18b341e3834d3c
Reviewed-on: https://go-review.googlesource.com/11201Reviewed-by: Andrew Gerrand <adg@golang.org>

Change-Id: I5917bea8bb35b0e725dcc56a68f3a70137cfc180
Reviewed-on: https://go-review.googlesource.com/9387Reviewed-by: Ian Lance Taylor <iant@golang.org>

This is a documentation fix that reflects the current reality.

Fixes #9673.

Change-Id: Ie436b277dfd1b68b13c67813d29c238d2c23b820
Reviewed-on: https://go-review.googlesource.com/11221Reviewed-by: Russ Cox <rsc@golang.org>

Fixes #4210.

Change-Id: Id981814a6e55a57403ce7a8ac45ab3ba081a3a86
Reviewed-on: https://go-review.googlesource.com/10925Reviewed-by: Russ Cox <rsc@golang.org>

This also includes some other minor updates to the documentation.

Change-Id: Iafab353727d7622d125b97fbdeaa81525b7a92aa
Reviewed-on: https://go-review.googlesource.com/11123Reviewed-by: Yves Junqueira <yves.junqueira@gmail.com>
Reviewed-by: Russ Cox <rsc@golang.org>

Indent the temporary file source code embedded in go_test.go, so that
we don't have temporary Go code in the first column.

No real changes to the tests, just formatting.

Change-Id: I416b4a812c8db452ea61afe63a00989ec598c228
Reviewed-on: https://go-review.googlesource.com/10926Reviewed-by: Russ Cox <rsc@golang.org>

Spell out what will happen if a declaration and definition is included
in the same file, should help people who run into duplicate symbol
errors and search for relevant keywords.

This edit is based on opening issue #11263 erroneously.

Change-Id: I0645a9433b8668d2ede9b9a3f6550d802c26388b
Reviewed-on: https://go-review.googlesource.com/11247Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I97812575ff9c69301a5ce2e1c814b40e1da32a55
Reviewed-on: https://go-review.googlesource.com/11271Reviewed-by: David Crawshaw <crawshaw@golang.org>

Updates #11268.

Change-Id: Ib0cabd1c1806e884df9e40f6a9a1cdecf2f76823
Reviewed-on: https://go-review.googlesource.com/11223Reviewed-by: David Crawshaw <crawshaw@golang.org>

A frame that tries to use the global palette when it has
not been given should result in an error, not an image
with no palette at all.

Fixes #11150.

Change-Id: If0c3a201a0ac977eee2b7a5dc68930c0c5787f40
Reviewed-on: https://go-review.googlesource.com/11064Reviewed-by: Nigel Tao <nigeltao@golang.org>

The compress/lzw encoder now rejects too-large input bytes, as of
https://go-review.googlesource.com/#/c/11227/, so we can't generate bad
GIFs programatically.

Change-Id: I0b32ce8e1f1776cd6997869db61e687430464e45
Reviewed-on: https://go-review.googlesource.com/11270Reviewed-by: Nigel Tao <nigeltao@golang.org>

Fixes #11142.

Change-Id: Id772c4364c47776d6afe86b0939b9c6281e85edc
Reviewed-on: https://go-review.googlesource.com/11227Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: Id9e8c3f89e021b9f389ab3c8403e6a8450fa9f5f
Reviewed-on: https://go-review.googlesource.com/11231Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

Add sentences to the docs explaining the limit on input
bytes implicit in the choice of litWidth, and the fact that
compress and decompress litWidth must match.

Fixes #11142.

Change-Id: I20cfb4df35739f7bfeb50b92c78249df3d47942c
Reviewed-on: https://go-review.googlesource.com/11063Reviewed-by: Nigel Tao <nigeltao@golang.org>

Some latency regressions have crept into our system over the past few
weeks. This CL fixes those by having the mark phase more aggressively
blacken objects so that the mark termination phase, a STW phase, has less
work to do. Three approaches were taken when the mark phase believes
it has no more work to do, ie all the work buffers are empty.
If things have gone well the mark phase is correct and there is
in fact little or no work. In that case the following items will
take very little time. If the mark phase is wrong this CL will
ferret that work out and give the mark phase a chance to deal with
it concurrently before mark termination begins.

When the mark phase first appears to be out of work, it does three things:
1) It switches from allocating white to allocating black to reduce the
number of unmarked objects reachable only from stacks.
2) It flushes and disables per-P GC work caches so all work must be in
globally visible work buffers.
3) It rescans the global roots---the BSS and data segments---so there
are fewer objects to blacken during mark termination. We do not rescan
stacks at this point, though that could be done in a later CL.
After these steps, it again drains the global work buffers.

On a lightly loaded machine the garbage benchmark has reduced the
number of GC cycles with latency > 10 ms from 83 out of 4083 cycles
down to 2 out of 3995 cycles. Maximum latency was reduced from
60+ msecs down to 20 ms.

Change-Id: I152285b48a7e56c5083a02e8e4485dd39c990492
Reviewed-on: https://go-review.googlesource.com/10590Reviewed-by: Austin Clements <austin@google.com>

Change-Id: I157879f5204d543eb3fc81c212d563b146473ba8
Reviewed-on: https://go-review.googlesource.com/11232Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Updates #11241

Change-Id: I573be85d0cfcf410f6125ecd2be8a3d292c40bbb
Reviewed-on: https://go-review.googlesource.com/11245Reviewed-by: Robert Griesemer <gri@golang.org>

See also issue #11271.

Change-Id: I34175f46ce137b14ca483500f673b0f8ee1f2108
Reviewed-on: https://go-review.googlesource.com/11262Reviewed-by: Alan Donovan <adonovan@google.com>

When a method is called using the Type.Method(receiver, args...) syntax
without the receiver, or enough arguments, provide the more helpful
error message "not enough arguments in call to method expression
Type.Method" instead of the old message "not enough arguments in call
to Type.Method".

Fixes #8385

Change-Id: Id5037eb1ee5fa93687d4a6557b4a8233b29e9df2
Reviewed-on: https://go-review.googlesource.com/2193Reviewed-by: Russ Cox <rsc@golang.org>

While we're at it, move some misplaced comment blocks around.

Change-Id: I1847d7f1ca1dbb8e5de737203c4ed6c66e112508
Reviewed-on: https://go-review.googlesource.com/10188Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

It's easy for someone who wants a time bigger than any
valid time to reach for time.Unix(1<<63-1, 0), so it
makes sense to explicit say such value is not valid.

Fixes #10906 (again).

Change-Id: If71e32472ae40d86c30e629b982406040a73c4c7
Reviewed-on: https://go-review.googlesource.com/10266Reviewed-by: Russ Cox <rsc@golang.org>

The Slicing-By-8 [1] algorithm has much performance improvements than
current approach. This patch only uses it for IEEE, which is the most
common case in practice.

There is the benchmark on Mac OS X 10.9:

benchmark                     old MB/s     new MB/s     speedup
BenchmarkIEEECrc1KB           349.40       353.03       1.01x
BenchmarkIEEECrc4KB           351.55       934.35       2.66x
BenchmarkCastagnoliCrc1KB     7037.58      7392.63      1.05x

This algorithm need 8K lookup table, so it's enabled only for block
larger than 4K.

We can see about 2.6x improvement for IEEE.

Change-Id: I7f786d20f0949245e4aa101d7921669f496ed0f7
Reviewed-on: https://go-review.googlesource.com/1863Reviewed-by: Russ Cox <rsc@golang.org>

Fixes #11272.

Change-Id: I78d666c20f4f7cb7116d37fd66b5f8b7d66c53c4
Reviewed-on: https://go-review.googlesource.com/11234Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Check that if a version is declared, for example
in '<?xml version="XX" ?>', version must be '1.0'.

Change-Id: I16ba9f78873a5f31977dcf75ac8e671fe6c08280
Reviewed-on: https://go-review.googlesource.com/8961Reviewed-by: Russ Cox <rsc@golang.org>

When the scanner receives a non-whitespace character in stateEndTop,
it creates an error message and caches it to return on the next
transition. nextValue() uses the scanner to sub-scan for a value
inside a larger JSON structure. Since stateEndTop is triggered
*after* the ending byte, whatever character immediately follows the
sub-value gets pulled into the scanner's state machine as well.
Even though it is not used and doesn't cause an error, it does
cause the state machine to allocate an error that will never be used.

The fix is to probe the state machine with whitespace after
scanEndObject or scanEndArray to see if the next character would
result in a scanEnd state transition. If so, we can return right
away without processing the next character and avoid triggering
an allocation.

benchmark                       old ns/op     new ns/op     delta
BenchmarkCodeEncoder            17022194      16611336      -2.41%
BenchmarkCodeMarshal            18443250      18090144      -1.91%
BenchmarkCodeDecoder            61502053      61010936      -0.80%
BenchmarkCodeUnmarshal          61410829      60363605      -1.71%
BenchmarkCodeUnmarshalReuse     59124836      58361772      -1.29%
BenchmarkUnmarshalString        602           603           +0.17%
BenchmarkUnmarshalFloat64       535           537           +0.37%
BenchmarkUnmarshalInt64         482           482           +0.00%
BenchmarkIssue10335             1206          799           -33.75%
BenchmarkSkipValue              17605751      18355391      +4.26%
BenchmarkEncoderEncode          612           604           -1.31%

benchmark                  old MB/s     new MB/s     speedup
BenchmarkCodeEncoder       114.00       116.82       1.02x
BenchmarkCodeMarshal       105.21       107.27       1.02x
BenchmarkCodeDecoder       31.55        31.81        1.01x
BenchmarkCodeUnmarshal     31.60        32.15        1.02x
BenchmarkSkipValue         111.63       107.07       0.96x

benchmark                  old allocs     new allocs     delta
BenchmarkIssue10335        11             4              -63.64%
BenchmarkEncoderEncode     2              2              +0.00%

benchmark                  old bytes     new bytes     delta
BenchmarkIssue10335        376           272           -27.66%
BenchmarkEncoderEncode     40            40            +0.00%

Fixes #10335

Change-Id: I3d4f2b67f7a038adfb33ba48bb6b680f528baf18
Reviewed-on: https://go-review.googlesource.com/9074Reviewed-by: Russ Cox <rsc@golang.org>

Suggest running 'go help gopath' when the running 'go install .'
and the folder is outside of GOPATH.

Added link to 'https://golang.org/doc/code.html' in gopath help
for more information.

Example output:

% go install .
go install: no install location for directory f:\x\badmessage outside GOPATH
        please run 'go help gopath' for more information

% go help gopath
... SNIP ...
See https://golang.org/doc/code.html for an example.

Fixes #8457

Change-Id: I0ef6ee3c65bb12af2168eafeb757258aa3835664
Reviewed-on: https://go-review.googlesource.com/9258Reviewed-by: Russ Cox <rsc@golang.org>

Fixes #10734.

Change-Id: I7a2c580b87749225668fbd7a005412c8eee6824d
Reviewed-on: https://go-review.googlesource.com/9823Reviewed-by: Russ Cox <rsc@golang.org>

Check for errors when reading the headers following the pax headers.

Fixes #11169.

Change-Id: Ifec4a949ec8df8b49fa7cb7a67eb826fe2282ad8
Reviewed-on: https://go-review.googlesource.com/11031Reviewed-by: Russ Cox <rsc@golang.org>