GODEBUG=netdns=1 prints a one-time strategy decision. (cgo or go DNS lookups)
GODEBUG=netdns=2 prints the per-lookup strategy as a function of the hostname.

The new "netcgo" build tag forces cgo DNS lookups.

GODEBUG=netdns=go (or existing build tag "netgo") forces Go DNS resolution.
GODEBUG=netdns=cgo (or new build tag "netcgo") forces libc DNS resolution.

Options can be combined with e.g. GODEBUG=netdns=go+1 or GODEBUG=netdns=2+cgo.

Fixes #11322
Fixes #11450

Change-Id: I7a67e9f759fd0a02320e7803f9ded1638b19e861
Reviewed-on: https://go-review.googlesource.com/11584Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: Ide5b0c81405fbf6b83a6f02527d629898e0fcf02
Reviewed-on: https://go-review.googlesource.com/12000Reviewed-by: Ian Lance Taylor <iant@golang.org>

sysmon triggers a GC if there has been no GC for two minutes.
Currently, this is a STW GC. There is no reason for this to be STW, so
make it concurrent.

Fixes #10261.

Change-Id: I92f3ac37272d5c2a31480ff1fa897ebad08775a9
Reviewed-on: https://go-review.googlesource.com/11955Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

The architecture-specific details will be updated and expanded in
a subsequent CL (or series thereof).

Update #10096

Change-Id: I59c6be1fcc123fe8626ce2130e6ffe71152c87af
Reviewed-on: https://go-review.googlesource.com/11954Reviewed-by: Russ Cox <rsc@golang.org>

Fix typo.

TBR=rsc

Change-Id: I85d1b46744a9a4524e7949e452cdebb53afe0740
Reviewed-on: https://go-review.googlesource.com/11959Reviewed-by: Rob Pike <r@golang.org>

Change-Id: Ie3d603a95826b9b6a7acd4825991f24c3c61408b
Reviewed-on: https://go-review.googlesource.com/11956Reviewed-by: Russ Cox <rsc@golang.org>

Change the default behavior when showing the package docs
for a command to elide the symbols. This makes

	go doc somecommand

show the top-level package docs only and hide the symbols,
which are probably irrelevant to the user. This has no effect
on explicit requests for internals, such as

	go doc somecommand.sometype

The new -cmd flag restores the old behavior.

Fixes #10733.

Change-Id: I4d363081fe7dabf76ec8e5315770ac3609592f80
Reviewed-on: https://go-review.googlesource.com/11953Reviewed-by: Russ Cox <rsc@golang.org>

They were missing from the inputs.
Unfortunately this means the .out files all have wrong line numbers,
but they are easy to update.

Change-Id: I254742f24ab803421f34d52d13b9afa93674edd6
Reviewed-on: https://go-review.googlesource.com/11958Reviewed-by: Russ Cox <rsc@golang.org>

This was added in commit 8b4278ff.

Change-Id: I95279f2779c2bab2767e34389fb4324900c01e6c
Reviewed-on: https://go-review.googlesource.com/11952Reviewed-by: Rob Pike <r@golang.org>

It was crashing.
This fixes the build for
GO15VENDOREXPERIMENT=1 go test -short runtime

Fixes #11416.

Change-Id: I74a9114cdd8ebafcc9d2a6f40bf500db19c6e825
Reviewed-on: https://go-review.googlesource.com/11964Reviewed-by: Russ Cox <rsc@golang.org>

This avoids both a write barrier and then dynamic initialization
globals of the form

	var x something
	var xp = unsafe.Pointer(&x)

Using static initialization avoids emitting a relocation for &x,
which helps cgo.

Fixes #9411.

Change-Id: I0dbf480859cce6ab57ab805d1b8609c45b48f156
Reviewed-on: https://go-review.googlesource.com/11693Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Russ Cox <rsc@golang.org>

Fixes #10884

Change-Id: I7cab3c96548867612f579d2cd4ec736309787443
Reviewed-on: https://go-review.googlesource.com/11961Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The recent https://golang.org/cl/11810 is reportedly a bit too
aggressive.

Apparently some HTTP requests in the wild do contain both a
Transfer-Encoding along with a bogus Content-Length. Instead of
returning a 400 Bad Request error, we should just ignore the
Content-Length like we did before.

Change-Id: I0001be90d09f8293a34f04691f608342875ff5c4
Reviewed-on: https://go-review.googlesource.com/11962Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The expansion of structure, array, slice, and map literals
does not use the right line number in its introduced assignments
to temporaries, which leads to incorrect line number attribution
for expressions in those literals.

Inlining also incorrectly replaced the line numbers of args to
inlined functions.

This was revealed in CL 9721 because a now-avoided temporary
assignment introduced the correct line number.
I.e. before CL 9721
  "tmp_wrongline := expr"
was transformed to
  "tmp_rightline := expr; tmp_wrongline := tmp_rightline"

Also includes a repair to CL 10334 involving line numbers
where a spurious -1 remained (should have been 0, now is 0).

Fixes #11400.

Change-Id: I3a4687efe463977fa1e2c996606f4d91aaf22722
Reviewed-on: https://go-review.googlesource.com/11730
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Sameer Ajmani <sameer@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Basic randomization of goroutine scheduling for -race mode.
It is probably possible to do much better (there's a paper linked
in the issue that I haven't read, for example), but this suffices
to introduce at least some unpredictability into the scheduling order.
The goal here is to have _something_ for Go 1.5, so that we don't
start hitting more of these scheduling order-dependent bugs
if we change the scheduler order again in Go 1.6.

For #11372.

Change-Id: Idf1154123fbd5b7a1ee4d339e93f97635cc2bacb
Reviewed-on: https://go-review.googlesource.com/11795Reviewed-by: Austin Clements <austin@google.com>

Fixes #11409

Change-Id: Ic1610e124b2d8b2b12310fc9538d5078cc7302a0
Reviewed-on: https://go-review.googlesource.com/11316Reviewed-by: Russ Cox <rsc@golang.org>

Fixes #11065.

Change-Id: Idd854facd5fa78c0334f86740f351d404f9a5b2d
Reviewed-on: https://go-review.googlesource.com/11511Reviewed-by: Russ Cox <rsc@golang.org>

Fixes #11414

Change-Id: I45a41b98554f00362d9222e9c68a441dbfc23cb8
Reviewed-on: https://go-review.googlesource.com/11700Reviewed-by: Russ Cox <rsc@golang.org>

Go's continuous build system depends on HTTP trailers for the buildlet
interface.

Andrew rewrote the makerelease tool to work in terms of Go's builder
system (now at x/build/cmd/release), but it previously could only
create GCE-based buildlets, which meant x/build/cmd/release couldn't
build the release for Darwin.

https://golang.org/cl/11901 added support for proxying buildlet
connections via the coordinator, but that exposed the fact that
httputil.ReverseProxy couldn't proxy Trailers. A fork of that code
also wasn't possible because net/http needlessly deleted the "Trailer"
response header in the Transport code.  This mistake goes back to
"release-branch.r56" and earlier but was never noticed because nobody
ever uses Trailers, and servers via ResponseWriter never had the
ability to even set trailers before this Go 1.5. Note that setting
trailers requires pre-declaring (in the response header) which
trailers you'll set later (after the response body). Because you could
never set them, before this release you could also never proxy them.

Change-Id: I2410a099921790dcd391675ae8610300efa19108
Reviewed-on: https://go-review.googlesource.com/11940Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>

Don't know why, but git deleted the previous version of this change.
This is the same change as https://go-review.googlesource.com/11884,
which I will now abandon, with a couple of fixes.

Almost all done now. Could use help with the TODOs.

Major missing piece is the trace command. Vendoring
section is also weak, but it's also undocumented elsewhere.

Change-Id: I5d8556b23aa6628eb7bf0e330d4dd8d4ac2157c5
Reviewed-on: https://go-review.googlesource.com/11887Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: If33ffe1da23a8463fc5479f453422d280b736372
Reviewed-on: https://go-review.googlesource.com/11865Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Don't talk about commands that no longer exist.

There are still references throughout the tree, mostly in comments,
but they provide a charming historical backdrop for the idle tourist.

Change-Id: I637ebdce05bbc7df5addcc46cb772d2bb9f3e073
Reviewed-on: https://go-review.googlesource.com/11885Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I78f0f9ac33db153c4a0d7f9866da20ebcd3d3639
Reviewed-on: https://go-review.googlesource.com/11872Reviewed-by: Rob Pike <r@golang.org>

The second (fallback) draw is a no-op, but it's a non-trivial amount of work.

Fixes #11550.

benchmark               old ns/op     new ns/op     delta
BenchmarkPaletted-4     16301219      7309568       -55.16%

Change-Id: Ic88c537b2b0c710cf517888f3dd15cb702dd142f
Reviewed-on: https://go-review.googlesource.com/11858Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Also add words about the assembler.

Change-Id: I9bd8cc88076f06b0eef36a07f57d1ad5d9261d8d
Reviewed-on: https://go-review.googlesource.com/11853Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #11508

Change-Id: I72e83893b76f75685d6edfe65ca6691d97539226
Reviewed-on: https://go-review.googlesource.com/11864Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This reverts commit 6f7961da.

Russ suggests changing the frozon syscall package and obviously it's a
better solution. Perhaps he will also let me know the way how to get the
project owners to agree later.

Fixes #11492.

Change-Id: I98f9f366b72b85db54b4acfc3a604b62fb6d783c
Reviewed-on: https://go-review.googlesource.com/11854
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #10616

Change-Id: I4ef25eb0be6ccf474976fdb5087dd2c62c66c510
Reviewed-on: https://go-review.googlesource.com/11811Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>

As per comments in cl/11834.

Change-Id: I285536b882fa9496e15d77d0d4c16ee913aca581
Reviewed-on: https://go-review.googlesource.com/11861Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Comment change only.

Change-Id: I2e32c2b34d5a5659ead6d6082b06e1b039bf1147
Reviewed-on: https://go-review.googlesource.com/11852Reviewed-by: Russ Cox <rsc@golang.org>

On some VMs two events can happen at the same time. For examples:
179827399 GoStart p=2 g=11 off=936359 g=11
179827399 GoUnblock p=2 g=0 off=936355 g=11
If we do non-stable sort, the events can be reordered making the trace inconsistent.
Do stable sort instead.

Batches are dumped in FIFO order, so if these same-time events are split into
separate batches, stable sort still works.

Events on different CPUs go into different batches and can be reordered.
But the intention is that causally-related events on different CPUs
will have larger (non-zero) time diff.

Update #11320

Change-Id: Id1df96af41dff68ea1782ab4b23d5afd63b890c9
Reviewed-on: https://go-review.googlesource.com/11834Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: Ied305480f22b60767c4628e5a31236ac01eafc86
Reviewed-on: https://go-review.googlesource.com/11825Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Changes suggested by Nigel Tao in https://go-review.googlesource.com/#/c/11635
after that had been submitted.

Change-Id: I7b28e1c8488c8565399a8017453dc7ff1fd215e8
Reviewed-on: https://go-review.googlesource.com/11832Reviewed-by: Nigel Tao <nigeltao@golang.org>

Integrate the latest trace-viewer changes.
It now handles nanoseconds without any issues (thanks to @egonelbre!).
So change timestamps from microseconds to nanoseconds.

Change-Id: I010f27effde7e80c9992e6f276f6912354d27df4
Reviewed-on: https://go-review.googlesource.com/11244Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Egon Elbre <egonelbre@gmail.com>

Everything in the library but crypto and net.

Change-Id: I89b21b9621e6d338fa1891da0eabba5d7d2fe349
Reviewed-on: https://go-review.googlesource.com/11820Reviewed-by: Russ Cox <rsc@golang.org>

Adding a mutex was easier than documenting it, and is consistent with
gob.

Fixes #9847

Change-Id: Ifa94c17e7c11643add81b35431ef840b794d78b1
Reviewed-on: https://go-review.googlesource.com/11682Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

See RFC 7230.

Thanks to Régis Leroy for the report.

Change-Id: Ic1779bc2180900430d4d7a4938cac04ed73c304c
Reviewed-on: https://go-review.googlesource.com/11810Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #11475

Change-Id: Ibaedbb732bb1b9f062bd5af7b866ec4758c724a7
Reviewed-on: https://go-review.googlesource.com/11770Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>

The optional Qualifier function determines what prefix to attach to
package-level names, enabling clients to qualify packages in different
ways, for example, using only the package name instead of its complete
path, or using the locally appropriate name for package given a set of
(possibly renaming) imports.

Prior to this change, clients wanting this behavior had to copy
hundreds of lines of complex printing logic.

Fun fact: (*types.Package).Path and (*types.Package).Name are valid
Qualifier functions.

We provide the RelativeTo helper function to create Qualifiers so that
the old behavior remains a one-liner.

Fixes golang/go#11133

This CL is a copy of https://go-review.googlesource.com/#/c/11692/
to the golang.org/x/tools repository.

Change-Id: I26d0f3644d077a26bfe350989f9c545f018eefbf
Reviewed-on: https://go-review.googlesource.com/11790Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>

We can't address more than this on amd64 anyway.

Fixes #9862.

Change-Id: Ifb1abae558e2e1ee2dc953a76995f3f08c60b1df
Reviewed-on: https://go-review.googlesource.com/11715Reviewed-by: Austin Clements <austin@google.com>