Currently we run profiling tests for around 200ms in short mode.
However, even on platforms with good profiling, these tests are
inherently flaky, especially on loaded systems like the builders.

To mitigate this, modify the profiling test harness so that if a test
fails in a way that could indicate there just weren't enough samples,
it retries with a longer duration.

This requires some adjustment to the profile checker to distinguish
"fatal" and "retryable" errors. In particular, we no longer consider
it a fatal error to get a profile with zero samples (which we
previously treated as a parse error). We replace this with a retryable
check that the total number of samples is reasonable.

Fixes #13943. Fixes #13871. Fixes #13223.

Change-Id: I9a08664a7e1734c5334b1f3792a56184fe314c4d
Reviewed-on: https://go-review.googlesource.com/18683Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Updates x/net/http2 to git rev eb066e3 for https://golang.org/cl/18932

Fixes #13925
Fixes #14061

Change-Id: I73f8c09232877404362358240b7b369bb9c76a12
Reviewed-on: https://go-review.googlesource.com/18934Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #14103

Change-Id: I89963643eccc902b809e04b7a14153acb0d242e1
Reviewed-on: https://go-review.googlesource.com/18933Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #14020

Change-Id: I454c2613912a7efcb464c6e6f3ac2e0ec89fb719
Reviewed-on: https://go-review.googlesource.com/18750Reviewed-by: Andrew Gerrand <adg@golang.org>
Reviewed-by: Chris Broadfoot <cbro@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

People who want to use -buildmode=c-archive in unusual cross-compilation
setups will need something like this.  It could also be done via (yet
another) environment variable but I use -extar by analogy with the
existing -extld.

Change-Id: I354cfabc4c470603affd13cd946997b3a24c0e6c
Reviewed-on: https://go-review.googlesource.com/18913Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I8c647e709d93a76636e04375609fceadf3754aa1
Reviewed-on: https://go-review.googlesource.com/18954Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #13938.

Change-Id: I0b4842b8bc22dc79323d6894c123cde638f52d3f
Reviewed-on: https://go-review.googlesource.com/18856Reviewed-by: Adam Langley <agl@golang.org>

Windows: putting spaces where they don't belong since Windows NT 3.1.

Fixes #14002.

Change-Id: I48ba8a7bfe3f27f83c8aa8355a8d355933d6c5df
Reviewed-on: https://go-review.googlesource.com/18855Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Add example of how to use the aes package to
implement AES encryption and decryption
within an application.

Per feedback, use more secure AES-GCM implementation as an
example in crypto/cipher instead of AES directly.

Change-Id: I84453ebb18e0bc79344a24171a031ec0d7ccec2e
Reviewed-on: https://go-review.googlesource.com/18803Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #14099.

Change-Id: I122e918bdc55fb185f4a4a797489b160219542d2
Reviewed-on: https://go-review.googlesource.com/18943
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Was part of #13822 but not in the first message, so I missed it.

Fixes #13822 again.

Change-Id: I775004fa8d47b6af293124605521ec396573e267
Reviewed-on: https://go-review.googlesource.com/18900
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I85fa5e672a476098f8711dcbb5b20ea1a3fa630d
Reviewed-on: https://go-review.googlesource.com/18953Reviewed-by: Ian Lance Taylor <iant@golang.org>

Use of the alternate signal stack on darwin/{arm,arm64} is reportedly
buggy, and the runtime function sigaltstack does nothing.  So don't
check the sigaltstack result to decide how to handle the signal stack.

Fixes #14070.

Change-Id: Ie97ede8895fad721e3acc79225f2cafcbe1f3a81
Reviewed-on: https://go-review.googlesource.com/18940
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>

Fixes #14084

Change-Id: Icbef5678ab3c4fd7eed2693006c47aca6d831d90
Reviewed-on: https://go-review.googlesource.com/18873Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Also don't nil out the Request or Response Body on error. Just leave
it in its previous broken state. The docs now say it's undefined, but
it always was.

Fixes #14036

Change-Id: I7fe175a36cbc01b4158f4dffacd8733b2ffa9999
Reviewed-on: https://go-review.googlesource.com/18726Reviewed-by: Rob Pike <r@golang.org>

Updates x/net/http2 to git rev 2e9cee70 for https://golang.org/cl/18801

Change-Id: I4689c5704bb0b12d569925f81c3e699857ea463e
Reviewed-on: https://go-review.googlesource.com/18931Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

When using c-archive/c-shared, the signal handler for SIGPROF will not
be installed, which means that runtime/pprof.StartCPUProfile won't work.
There is no really good solution here, as the main program may want to
do its own profiling.  For now, just document that runtime/pprof doesn't
work as expected, but that it will work if you use Notify to install the
Go signal handler.

Fixes #14043.

Change-Id: I7ff7a01df6ef7f63a7f050aac3674d640a246fb4
Reviewed-on: https://go-review.googlesource.com/18911
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>

Change-Id: Ic2a326d41783fb591148748dbcccfd3855091437
Reviewed-on: https://go-review.googlesource.com/18912Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Thanks to Régis Leroy for noticing.

Change-Id: I5ca2402efddab4e63d884a9d315fc1394e514cb7
Reviewed-on: https://go-review.googlesource.com/18871Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

On NetBSD and DragonFly a newly created thread inherits the signal stack
of the creating thread.  That means that in a cgo program a C thread
created using pthread_create will get the signal stack of the creating
thread, most likely a Go thread.  This will then lead to chaos if two
signals occur simultaneously.

We can't fix the general case.  But we can fix the case of a C thread
that calls a Go function, by installing a new signal stack and then
dropping it when we return to C.  That will break the case of a C thread
that calls sigaltstack and then calls Go, because we will drop the C
thread's alternate signal stack as we return from Go.  Still, this is
the 1.5 behavior.  And what else can we do?

Fixes #14051.
Fixes #14052.
Fixes #14067.

Change-Id: Iee286ca50b50ec712a4d929c7121c35e2383a7b9
Reviewed-on: https://go-review.googlesource.com/18835Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
Reviewed-by: Russ Cox <rsc@golang.org>

Pass -c to generate an object.  Pass GOPKGPATH as a symbol, not a
string.  Pass -xassembler-with-cpp so that the preprocessor is run.

Change-Id: I84690a73cc580bb05724ed07c120cec9cfd5e48b
Reviewed-on: https://go-review.googlesource.com/18733
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Add test for assembly errors, to verify fix.
Make sure invalid instruction errors are printed just once
(was printing them once per span iteration, so typically twice).

Fixes #13282.

Change-Id: Id5f66f80a80b3bc4832e00084b0a91f1afec7f8f
Reviewed-on: https://go-review.googlesource.com/18858Reviewed-by: Rob Pike <r@golang.org>

Apparently the darwin/386 builder does not enable cgo.
This failure turned up running

	GOARCH=386 GOHOSTARCH=386 ./all.bash

on my Mac.

Change-Id: Ia2487c4fd85d4b0f9f564880f22d9fde379946c3
Reviewed-on: https://go-review.googlesource.com/18859Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #13757.

Change-Id: I1b52593df8df0e98ce7342767eb34eccecc11761
Reviewed-on: https://go-review.googlesource.com/18854
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Requested off-list.
Trivial to add and more importantly trivial to test.

ANDNL
ANDNQ
BEXTRL
BEXTRQ
BZHIL
BZHIQ
MULXL
MULXQ
PDEPL
PDEPQ
PEXTL
PEXTQ
SARXL
SARXQ
SHRXL
SHRXQ

Change-Id: I3d46a0f653b81dd003ff6d2a394d8ce96a573b63
Reviewed-on: https://go-review.googlesource.com/18857Reviewed-by: Rob Pike <r@golang.org>

Add amd64 instructions I promised to add for Go 1.6
at the beginning of January.

These may be the last instructions added by hand.
I intend to generate the whole set mechanically for Go 1.7.

Fixes #13822.

Change-Id: I8c6bae2efd25f717f9ec750402e50f408a911d2b
Reviewed-on: https://go-review.googlesource.com/18853Reviewed-by: Rob Pike <r@golang.org>

Use the standard names, for discoverability.
Use the standard register arguments, for correctness.
Implement all possible arguments, for completeness.
Enable the corresponding tests now that everything is standard.
Update the uses in package runtime.

Fixes #14068.

Change-Id: I8e1af9a41e7d02d98c2a82af3d4cdb3e9204824f
Reviewed-on: https://go-review.googlesource.com/18852
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

Fixes #4816.

Change-Id: Ibeaa69f57b7519d56df4ea357edf8d9dc2102ffe
Reviewed-on: https://go-review.googlesource.com/18851Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Generated by x86test, from https://golang.org/cl/18842
(still in progress).

The commented out lines are either missing or misspelled
or incorrectly handled instructions.

For #4816, #8037, #13822, #14068, #14069.

Change-Id: If309310c97d9d2a3c71fc64c51d4a957e9076ab7
Reviewed-on: https://go-review.googlesource.com/18850Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Not much testing yet, but the test now exists.

Another step toward #13822.

Change-Id: Idb2b06bf53a6113c83008150b4c0b631bb195279
Reviewed-on: https://go-review.googlesource.com/18844Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>

Tests for this and many other instructions are in a separate followup CL.

For #14068.

Change-Id: I6955315996a34d7fb79369b9d9a0119d11745e85
Reviewed-on: https://go-review.googlesource.com/18849Reviewed-by: Rob Pike <r@golang.org>

Ilya added POPCNT in a CL earlier this month but it's really only POPCNTQ.
The other forms still need to be added.

For #4816.

Change-Id: I1186850d32ad6d5777475c7808e6fc9d9133e118
Reviewed-on: https://go-review.googlesource.com/18848Reviewed-by: Rob Pike <r@golang.org>

Change-Id: I5b749c575e0ec78fb3c50d056899bd1fe5d91853
Reviewed-on: https://go-review.googlesource.com/18847Reviewed-by: Rob Pike <r@golang.org>

Not recognized in any instructions yet, but this lets the
assembler parse them at least.

For #14068.

Change-Id: Id4f7329a969b747a867ce261b20165fab2cdcab8
Reviewed-on: https://go-review.googlesource.com/18846Reviewed-by: Rob Pike <r@golang.org>

Also, remove output file if there are encoding errors.
The extra reports are convenient.
Removing the output file is very important.
Noticed while testing.

Change-Id: I0fab17d4078f93c5a0d6d1217d8d9a63ac789696
Reviewed-on: https://go-review.googlesource.com/18845Reviewed-by: Rob Pike <r@golang.org>

Instead of two parallel files that look almost identical,
mark the expected differences in the original file.

The annotations being added here keep the tests passing,
but they also make clear a number of printing or parsing
errors that were not as easily seen when the data was
split across two files.

Fix a few diagnostic problems in cmd/internal/obj as well.

A step toward #13822.

Change-Id: I997172681ea6fa7da915ff0f0ab93d2b76f8dce2
Reviewed-on: https://go-review.googlesource.com/18823
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I2609660b10a16ec2a256fc9c8e046ba4ae67963f
Reviewed-on: https://go-review.googlesource.com/18880Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: Ica7f2a000eb1d89d5b02cb8c6f1596ddc04bfb26
Reviewed-on: https://go-review.googlesource.com/18890Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #14050.

Change-Id: I2d9c32213b0da35703edf28f92ed3efb23325921
Reviewed-on: https://go-review.googlesource.com/18792
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Add docs for valid uses of Pointer.
Then document change made for #13372 in CL 18584.

Fixes #8994.

Change-Id: Ifba71e5aeafd11f684aed0b7ddacf3c8ec07c580
Reviewed-on: https://go-review.googlesource.com/18640Reviewed-by: Alan Donovan <adonovan@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Rick Hudson <rlh@golang.org>