OpenBSD ships with GCC 4.2, the last version of GCC that used GPLv2.
As that is quite old (current GCC version is GCC 9, GCC 4.2 was
released in 2007), default to clang.

Change-Id: Ib93e7b4f4f3ffb9e047e60ffca3696d26ab08aac
Reviewed-on: https://go-review.googlesource.com/c/go/+/193621
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Add block method to preserve loop depth when evaluating statements in a
block, so escape analysis can handle looping label more precisely.

Updates #22438

Change-Id: I39b306544a6c0ee3fcbebbe0d0ee735cb71773e6
Reviewed-on: https://go-review.googlesource.com/c/go/+/193517
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Change-Id: Ic8d8399f726c1f9376499fdae92bea41632586ff
Reviewed-on: https://go-review.googlesource.com/c/go/+/193602Reviewed-by: Jonathan Amsterdam <jba@google.com>

Updates #21450

Change-Id: Ia31c20b52bae5daeb33d918234c2f0944a8aeb07
GitHub-Last-Rev: cc8554477024277c3c1b4122344e9d14427680b3
GitHub-Pull-Request: golang/go#33489
Reviewed-on: https://go-review.googlesource.com/c/go/+/189137
Run-TryBot: Sylvain Zimmer <sylvinus@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This commit improves how registers get mapped to wasm variables. This
is a preparation for future improvements (e.g. adding 32 bit float
registers).

Change-Id: I374c80b2d6c9bcce6b0e373fe921b5ad4dee40ff
Reviewed-on: https://go-review.googlesource.com/c/go/+/191777
Run-TryBot: Richard Musiol <neelance@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

This change makes it so that if we're already finding ourselves in a
situation where we've done more scan work than expected in the
steady-state (that is, 50% of heap_scan for GOGC=100), then we fall back
on the hard heap goal instead of continuing to assume the expected case.

In some cases its possible that we're already doing more scan work than
expected, and if GC assists come in just at that window where we notice
it, they might accumulate way too much assist credit, causing undue heap
growths if GOMAXPROCS=1 (since the fractional background worker isn't
guaranteed to fire). This case seems awfully specific, and that's
because it's exactly the case for TestGcSys, which has been flaky for
some time as a result.

Fixes #28574, #27636, and #27156.

Change-Id: I771f42bed34739dbb1b84ad82cfe247f70836031
Reviewed-on: https://go-review.googlesource.com/c/go/+/184097
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Tests may accept positional arguments, in which case the -test.timeout
flag must be passed before those arguments.

Fixes #34072

Change-Id: I5b92d7c0edc4f9e1efb63b0733937b76236c0eff
Reviewed-on: https://go-review.googlesource.com/c/go/+/193297
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This adds a platform-independent implementation of nacl's faketime
support. It can be enabled by setting the faketime build tag.

Updates #30439.

Change-Id: Iee097004d56d796e6d2bfdd303a092c067ade87e
Reviewed-on: https://go-review.googlesource.com/c/go/+/192740
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

If the faketime build tag is set, this causes syscall.Write for FDs 1
and 2 to redirect to runtime.write, since that's where we'll apply the
faketime framing. This is equivalent to what nacl currently does in
naclFile.write.

We do this on all of the platforms except nacl, which has its own
faketime support and we're about to remove, and Windows, which would
require other changes to support faketime so we're leaving alone for
now.

Updates #30439.

Change-Id: I138a5ca63577d92d15b5437d037bd3159fa84ee7
Reviewed-on: https://go-review.googlesource.com/c/go/+/192739
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

In preparation for general faketime support, this renames the existing
nanotime, walltime, and write functions to nanotime1, walltime1, and
write1 and wraps them with trivial Go functions. This will let us
inject different implementations on all platforms when faketime is
enabled.

Updates #30439.

Change-Id: Ice5ccc513a32a6d89ea051638676d3ee05b00418
Reviewed-on: https://go-review.googlesource.com/c/go/+/192738
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #34049

Change-Id: I817b83ee2d0ca6d01ec64998f14bc4f32e365d66
Reviewed-on: https://go-review.googlesource.com/c/go/+/193259
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>

You can't call Unwrap on the return value of fmt.Errorf, but
you can pass the result to errors.Unwrap.

Also, move the description of the Unwrap function up so the
example makes sense.

Fixes #34061.

Change-Id: Ica07c44665c5e65deea4aa6a146fc543a5a0a99d
Reviewed-on: https://go-review.googlesource.com/c/go/+/193298
Run-TryBot: Jonathan Amsterdam <jba@google.com>
Reviewed-by: Katie Hockman <katie@golang.org>

Fixes #34056.

Change-Id: I2c9b7a20d19f458df5dcc376e29bee6be1f09f7a
Reviewed-on: https://go-review.googlesource.com/c/go/+/193277Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This change makes it so that worldsema isn't held across the mark phase.
This means that various operations like ReadMemStats may now stop the
world during the mark phase, reducing latency on such operations.

Only three such operations are still no longer allowed to occur during
marking: GOMAXPROCS, StartTrace, and StopTrace.

For the former it's because any change to GOMAXPROCS impacts GC mark
background worker scheduling and the details there are tricky.

For the latter two it's because tracing needs to observe consistent GC
start and GC end events, and if StartTrace or StopTrace may stop the
world during marking, then it's possible for it to see a GC end event
without a start or GC start event without an end, respectively.

To ensure that GOMAXPROCS and StartTrace/StopTrace cannot proceed until
marking is complete, the runtime now holds a new semaphore, gcsema,
across the mark phase just like it used to with worldsema.

Fixes #19812.

Change-Id: I15d43ed184f711b3d104e8f267fb86e335f86bf9
Reviewed-on: https://go-review.googlesource.com/c/go/+/182657
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Add a space before build tag comments so it corresponds to the format
documented at https://golang.org/pkg/go/build/.

Change-Id: I8349d0343597e304b97fb5479847231ed8945b1a
Reviewed-on: https://go-review.googlesource.com/c/go/+/193237
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The exception allowed a specific intermediate [1] to chain up to a
broken root that lacked the CA:TRUE X509v3 Basic Constraint.

The broken root [2] is expiring at the end of 2019, so we can remove the
exception in Go 1.14.

Moreover, there is a reissued version of that root [3] (same Subject and
SPKI, valid CA) which expires in 2029, so root stores should have
migrated to it already, making the exception unnecessary.

[1]: https://crt.sh/?caid=57
[2]: https://crt.sh/?id=1616049
[3]: https://crt.sh/?id=55

Change-Id: I43f51100982791b0e8bac90d143b60851cd46dfc
Reviewed-on: https://go-review.googlesource.com/c/go/+/193038
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Right now we generate hash functions for all types, just in case they
are used as map keys. That's a lot of wasted effort and binary size
for types which will never be used as a map key. Instead, generate
hash functions only for types that we know are map keys.

Just doing that is a bit too simple, since maps with an interface type
as a key might have to hash any concrete key type that implements that
interface. So for that case, implement hashing of such types at
runtime (instead of with generated code). It will be slower, but only
for maps with interface types as keys, and maybe only a bit slower as
the aeshash time probably dominates the dispatch time.

Reorg where we keep the equals and hash functions. Move the hash function
from the key type to the map type, saving a field in every non-map type.
That leaves only one function in the alg structure, so get rid of that and
just keep the equal function in the type descriptor itself.

cmd/go now has 10 generated hash functions, instead of 504. Makes
cmd/go 1.0% smaller. Update #6853.

Speed on non-interface keys is unchanged. Speed on interface keys
is ~20% slower:

name                  old time/op  new time/op  delta
MapInterfaceString-8  23.0ns ±21%  27.6ns ±14%  +20.01%  (p=0.002 n=10+10)
MapInterfacePtr-8     19.4ns ±16%  23.7ns ± 7%  +22.48%   (p=0.000 n=10+8)

Change-Id: I7c2e42292a46b5d4e288aaec4029bdbb01089263
Reviewed-on: https://go-review.googlesource.com/c/go/+/191198
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>

Change-Id: I3340561c0b17bf28d8d480e00f5bc8afb2a897ef
Reviewed-on: https://go-review.googlesource.com/c/go/+/193041
Run-TryBot: Andrew Bonventre <andybons@golang.org>
Reviewed-by: Katie Hockman <katie@golang.org>

Updates #31563
Fixes #34041

Change-Id: Ib9fdcd2f83d867fd31b42eab3a813f5cef88860e
Reviewed-on: https://go-review.googlesource.com/c/go/+/193077
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>

The distribution of hash outputs when varying the seed is
not good enough on 32-bit platforms.

This isn't a likely attack vector (the adversary controlling the seed),
so it isn't a huge deal. Would be nice to fix, though. For now, just
skip this test.

Fixes #33988

Change-Id: Icf51ab687fc215422a5492ae78e6f414b33e04cb
Reviewed-on: https://go-review.googlesource.com/c/go/+/193078
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Assinging to 1-element array/1-field struct variable is considered clobbering
the whole variable. By emitting OpVarDef in this case, liveness analysis
can now know the variable is redefined.

Also, the isfat is not necessary anymore, and will be removed in follow up CL.

Fixes #33916

Change-Id: Iece0d90b05273f333d59d6ee5b12ee7dc71908c2
Reviewed-on: https://go-review.googlesource.com/c/go/+/192979
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Fix a buglet in abbrev processing related to DW_FORM_indirect. When
reading an abbrev entry if we encounter an attribute with form
DW_FORM_indirect, leave the class as ClassUnknown, then when the
abbrev is walked during the reading of the DIE fill in the class based
on the value read at that point (code for handling DW_FORM_indirect
seems to be already partially in place in the DIE reader).

Updates #33488.

Change-Id: I9dc89abf5cc8d7ea96824c0011bef979de0540bf
Reviewed-on: https://go-review.googlesource.com/c/go/+/190158
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

In general, a conversion to interface type may require values to be
boxed, which in turn necessitates escape analysis to determine whether
the boxed representation can be stack allocated.

However, esc.go used to unconditionally print escape analysis
decisions about OCONVIFACE, even for conversions that don't require
boxing (e.g., pointers, channels, maps, functions).

For test compatibility with esc.go, escape.go similarly printed these
useless diagnostics. This CL removes the diagnostics, and updates test
expectations accordingly.

Change-Id: I97c57a4a08e44d265bba516c78426ff4f2bf1e12
Reviewed-on: https://go-review.googlesource.com/c/go/+/192697
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

While here, change the params to be easier to understand: "t" is now
always the type being updated, and "underlying" is now used to
represent the underlying type.

Updates #33658.

Change-Id: Iabb64414ca3abaa8c780e4c9093e0c77b76fabf9
Reviewed-on: https://go-review.googlesource.com/c/go/+/192724
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Robert Griesemer <gri@golang.org>

This CL extends {defer,resume}checkwidth to support nesting, which
simplifies usage.

Updates #33658.

Change-Id: Ib3ffb8a7cabfae2cbeba74e21748c228436f4726
Reviewed-on: https://go-review.googlesource.com/c/go/+/192721
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Robert Griesemer <gri@golang.org>

Change-Id: I6e9d47865c198299d497911c58235cd40f775e34
Reviewed-on: https://go-review.googlesource.com/c/go/+/175138
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>

Also add a few other missing constants.

Also rerun current version of stringer.

Change-Id: I004ef27f6b40fe2cab64c52d169255dfea43fa01
Reviewed-on: https://go-review.googlesource.com/c/go/+/175137
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

This CL implements one lock per order of stackpool. It improves performance when mutator stack growth deeply, see benchmark below:

```
name                old time/op  new time/op  delta
StackGrowth-8       3.60ns ± 5%  3.59ns ± 1%    ~     (p=0.794 n=10+9)
StackGrowthDeep-8    370ns ± 1%   335ns ± 1%  -9.47%  (p=0.000 n=9+9)
StackCopyPtr-8      72.6ms ± 0%  71.6ms ± 1%  -1.31%  (p=0.000 n=9+9)
StackCopy-8         53.5ms ± 0%  53.2ms ± 1%  -0.54%  (p=0.006 n=8+9)
StackCopyNoCache-8   100ms ± 0%    99ms ± 0%  -0.70%  (p=0.000 n=8+8)
```

Change-Id: I1170d3fd9e6ff8516e25f669d0aaf1861311420f
GitHub-Last-Rev: 13b820cddd8008079c98d01ac22dd123a46a6603
GitHub-Pull-Request: golang/go#33399
Reviewed-on: https://go-review.googlesource.com/c/go/+/188478
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Change-Id: I4e7b0e99fd0f6f7d6a8ef60e9d3cb5baeb80a2b6
Reviewed-on: https://go-review.googlesource.com/c/go/+/191617
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Those configurations currently lack builders, and it is not clear to
me what state their tests are in.

The Go porting policy¹ requires builders for all active ports, so
let's not claim support until that requirement is met.

¹https://golang.org/wiki/PortingPolicy#requirements-for-a-new-port

Updates #30824
Updates #31656
Updates #34035
Updates #34036

Change-Id: I6496de9d92fb8546048abf139cf10546a47e314b
Reviewed-on: https://go-review.googlesource.com/c/go/+/192997Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>

This reverts CL 191759.

Reason for revert: broke most Go programs using the time package on Wine,
including on 4.15, the latest stable version. Only wine-staging (with
experimental patches) contains an upstream fix we could rely on.

Change-Id: Ic8ba126022e54f412174042fbb9abed82d5eb318
Reviewed-on: https://go-review.googlesource.com/c/go/+/192622
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

Change-Id: Icf7e1dab82aa48cc693eb4da8a564dff23312741
Reviewed-on: https://go-review.googlesource.com/c/go/+/192745
Run-TryBot: Andrew Bonventre <andybons@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>

Fixes #33954

Change-Id: Idfe71bf825adcd7cbf70cd139b3e779963394ff6
Reviewed-on: https://go-review.googlesource.com/c/go/+/192105
Run-TryBot: Andrew Bonventre <andybons@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Katie Hockman <katie@golang.org>

These changes make cmd/doc -src deterministic, or, more precisely,
go/ast.MergePackageFiles, which is used by cmd/doc. So far the order of
comments depended on the package file map iteration order.

cmd/doc with -src flag has been inserting and omitting random comments
ever since the addition of -src flag. After investigating the code path
with the debugger, I’ve noticed that ast.File.Comments slice order changes
between invocations of the command. The bug was introduced in 3e24f2d6,
which ironically claimed to “fix formatting of -src output”. The commit
implemented the collection of comments by iterating over the map and
c7cdce13 “godoc: make ?m=src mode deterministic” did’t actually make
go/ast.MergePackageFiles deterministic.

I’ve found this issue after running “go doc -src sync.WaitGroup.Wait”.
There are likely other packages and functions affected, but the bug
should be somewhat reproducible across all Go versions.

Change-Id: Iae223e99550c0a3b54005c5cde36f909e655b66b
GitHub-Last-Rev: c49532f79fcd7529d7ad1a369c467abc59d4df0a
GitHub-Pull-Request: golang/go#33553
Reviewed-on: https://go-review.googlesource.com/c/go/+/189477
Run-TryBot: Agniva De Sarker <agniva.quicksilver@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

Fixes #33743.

Change-Id: I80621321d56b6cf312a86e272800f1ad03c5544c
GitHub-Last-Rev: d91cb3697516ccfc3f956e97837404cbfee5922f
GitHub-Pull-Request: golang/go#33856
Reviewed-on: https://go-review.googlesource.com/c/go/+/191879
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>

Some were never used, and some haven't been used for years.

One exception is net/http's readerAndCloser, which was only used in a
test. Move it to a test file.

While at it, remove a check in regexp that could never fire; the field
is an uint32, so it can never be negative.

Change-Id: Ia2200f6afa106bae4034045ea8233b452f38747b
Reviewed-on: https://go-review.googlesource.com/c/go/+/192621
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: Ib637381ab8a12aeb798576b781e1b3c458ba812d
GitHub-Last-Rev: 12994496b6b636d75564e5ae7e938b65bca526df
GitHub-Pull-Request: golang/go#34017
Reviewed-on: https://go-review.googlesource.com/c/go/+/192877Reviewed-by: Daniel Martí <mvdan@mvdan.cc>

Fixes #33385

Change-Id: I497ccd868d408a9c5648c72aa5ce41221368daf4
GitHub-Last-Rev: 3bf483808e10a13c522df02c2fc55fe278044680
GitHub-Pull-Request: golang/go#33423
Reviewed-on: https://go-review.googlesource.com/c/go/+/188677Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>

scanEnd is delayed one byte so we decrement
the scanner bytes count by 1 to ensure that
this value is correct in the next call of Decode.

Fixes #32399

Change-Id: I8c8698e7f95bbcf0373aceaa05319819eae9d86f
GitHub-Last-Rev: 0ac25d8de23d38c7ac577faddc6983571023f561
GitHub-Pull-Request: golang/go#32598
Reviewed-on: https://go-review.googlesource.com/c/go/+/182117Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The URL port is already checked in net/url, so we can remove the redundant validation in net/http.

Fixes #33600

Change-Id: I62511a452df6262d4b66180933758d34627ff9df
GitHub-Last-Rev: c19afa31025fee68ba0601bb75e9e20e09a36822
GitHub-Pull-Request: golang/go#33611
Reviewed-on: https://go-review.googlesource.com/c/go/+/190057
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>