The information that's used to generate DWARF location lists is very
ssa.Value centric; it uses Values as start and end coordinates to define
ranges. That mostly works fine, but control flow instructions don't come
from Values, so the ranges couldn't cover them.

Control flow instructions are generated when the SSA representation is
converted to assembly, so that's the best place to extend the ranges
to cover them. (Before that, there's nothing to refer to, and afterward
the boundaries between blocks have been lost.) That requires block
information in the debugInfo type, which then flows down to make
everything else awkward. On the plus side, there's a little less copying
slices around than there used to be, so it should be a little faster.

Previously, the ranges for empty blocks were not very meaningful. That
was fine, because they had no Values to cover, so no debug information
was generated for them. But they do have control flow instructions
(that's why they exist) and so now it's important that the information
be correct. Introduce two sentinel values, BlockStart and BlockEnd, that
denote the boundary of a block, even if the block is empty. BlockEnd
replaces the previous SurvivedBlock flag.

There's one more problem: the last instruction in the function will be a
control flow instruction, so any live ranges need to be extended past
it. But there's no instruction after it to use as the end of the range.
Instead, leave the EndProg field of those ranges as nil and fix it up to
point to past the end of the assembled text at the very last moment.

Change-Id: I81f884020ff36fd6fe8d7888fc57c99412c4245b
Reviewed-on: https://go-review.googlesource.com/63010Reviewed-by: Alessandro Arzilli <alessandro.arzilli@gmail.com>
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Currently, methods are sorted by name. This happens to guarantee that
exported ASCII methods appear before non-exported ASCII methods, but
this breaks down when Unicode method names are considered.

Type.Method already accounts for this by always indexing into the
slice returned by exportedMethods. This CL makes Value.Method do the
same.

Fixes #22073.

Change-Id: I9bfc6bbfb7353e0bd3c439a15d1c3da60d16d209
Reviewed-on: https://go-review.googlesource.com/66770
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>

Updated page to Page to match with the sample code

Fixes #21773

Change-Id: Ia884a22fd587860c7a6148103b2b474425e45284
Reviewed-on: https://go-review.googlesource.com/66790Reviewed-by: Ian Lance Taylor <iant@golang.org>

The function dumpbvtypes has no use case anymore, so we remove it with
this change.

Change-Id: I1e0323542be2bcc683b75dffde76b222e087c285
Reviewed-on: https://go-review.googlesource.com/66370Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Updates #21856

Change-Id: I9baa51fe23e6dd2fcf9dd14f7acfaf7457571e1d
Reviewed-on: https://go-review.googlesource.com/66334
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>

Also changed name from TestUnix... to TestUnixgram....

Updates #21965

Change-Id: I2833110b77e9fe1b28d4a15feb3d70453ab98d3b
Reviewed-on: https://go-review.googlesource.com/66333
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
Reviewed-by: Rob Pike <r@golang.org>

Very similar fix to the one made in golang.org/cl/65655. This time it's
for switches on interface values, as we look for duplicates in a
different manner to keep types in mind.

As before, add a small regression test.

Updates #22001.
Fixes #22063.

Change-Id: I9a55d08999aeca262ad276b4649b51848a627b02
Reviewed-on: https://go-review.googlesource.com/66450
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

The fields wantbytes and wantraw in the test struct `conversionTest` has
been forgotten to include in the TestConversions function.

Change-Id: I6dab69e76de3799a1bbf9fa09a15607e55172114
Reviewed-on: https://go-review.googlesource.com/66610Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Combined the Split and Join call with a Replace. This simplifies
the code as well as makes it fast.

Micro-benchmarks show good improvements -

func BenchmarkJoinSplit(b *testing.B) {
  for n := 0; n < b.N; n++ {
    strings.Join(strings.Split("this string has some spaces", " "), "")
  }
}

func BenchmarkReplace(b *testing.B) {
  for n := 0; n < b.N; n++ {
    strings.Replace("this string has some spaces", " ", "", -1)
  }
}

name         old time/op    new time/op    delta
JoinSplit-4     308ns ± 2%     192ns ± 4%  -37.60%  (p=0.008 n=5+5)

name         old alloc/op   new alloc/op   delta
JoinSplit-4      144B ± 0%       64B ± 0%  -55.56%  (p=0.008 n=5+5)

name         old allocs/op  new allocs/op  delta
JoinSplit-4      3.00 ± 0%      2.00 ± 0%  -33.33%  (p=0.008 n=5+5)

Change-Id: I1dc32105ae7a0be5a43ab0bedde992cefbed5d7d
Reviewed-on: https://go-review.googlesource.com/66590
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Adding the "https://" scheme allows godoc to properly detect
the URL and provide a hyperlink for it.

Change-Id: I76dc309368c86975de01bc6e6e9196037b2114d7
Reviewed-on: https://go-review.googlesource.com/66570Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The reflect API normally grants only read-only access to non-exported
fields, but it specially handles non-exported embedded fields so that
users can still fully access promoted fields and methods. For example,
if v.Field(i) refers to a non-exported embedded field, it would be
limited to RO access. But if v.Field(i).Field(j) is an exported field,
then the resulting Value will have full access.

However, the way this was implemented allowed other operations to be
interspersed between the Field calls, which could grant inappropriate
access.

Relatedly, Elem() is safe to use on pointer-embeddings, but it was
also being allowed on embeddings of interface types. This is
inappropriate because it could allow accessing methods of the dynamic
value's complete method set, not just those that were promoted via the
interface embedding.

Fixes #22031.
Fixes #22053.

Change-Id: I9db9be88583f1c1d80c1b4705a76f23a4379182f
Reviewed-on: https://go-review.googlesource.com/66331
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Currently the FreeBSD CPU affinity code assumes that the maximum
GOMAXPROCS is 256, but we just removed that limit.

This commit rewrites the FreeBSD CPU affinity code to raise the CPU
count limit to 65,536, like the Linux CPU affinity code, and to
degrade more gracefully if we do somehow go over that.

Change-Id: Ic4ca7f88bd8b9448aae4dbd43ef21a6c1b8fea63
Reviewed-on: https://go-review.googlesource.com/66291
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

allp now has length gomaxprocs, which means none of allp[i] are nil or
in state _Pdead. This lets replace several different styles of loops
over allp with normal range loops.

for i := 0; i < gomaxprocs; i++ { ... } loops can simply range over
allp. Likewise, range loops over allp[:gomaxprocs] can just range over
allp.

Loops that check for p == nil || p.state == _Pdead don't need to check
this any more.

Loops that check for p == nil don't have to check this *if* dead Ps
don't affect them. I checked that all such loops are, in fact,
unaffected by dead Ps. One loop was potentially affected, which this
fixes by zeroing p.gcAssistTime in procresize.

Updates #15131.

Change-Id: Ifa1c2a86ed59892eca0610360a75bb613bc6dcee
Reviewed-on: https://go-review.googlesource.com/45575
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Now that allp is dynamically allocated, there's no need for a hard cap
on GOMAXPROCS.

Fixes #15131.

Change-Id: I53eee8e228a711a818f7ebce8d9fd915b3865eed
Reviewed-on: https://go-review.googlesource.com/45574
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This makes it possible to eliminate the hard cap on GOMAXPROCS.

Updates #15131.

Change-Id: I4c422b340791621584c118a6be1b38e8a44f8b70
Reviewed-on: https://go-review.googlesource.com/45573
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>

Correcting values is allowed per the syscall package rules, so update
these constants to their correct value on ppc64/ppc64le. The values now
match the corresponding constants in x/sys/unix.

Update #19560
Fixes #22000

Change-Id: I1d358de345766ec96e15dfcc8911fe2f39fb0ddb
Reviewed-on: https://go-review.googlesource.com/66510
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes: #22052

Change-Id: Ia056871b35ecc1a8c5ac891402fc1c5702731623
Reviewed-on: https://go-review.googlesource.com/66330
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Undoes this part of https://golang.org/cl/5447061 by using the
OS-specific open and close functions, and adding a read function.

Change-Id: If37ef43eb5df8554fc03f3922bbc2f785129bb9c
Reviewed-on: https://go-review.googlesource.com/66271
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Joe Tsai <joetsai@google.com>

Loading and testing timezones is currently implemented using several,
partly redundant, OS specific data structures and functions. This
change merges most of that code into OS independent implementations.

Change-Id: Iae2877c5f48d1e4a9de9ce55d0530d52e24cf96e
Reviewed-on: https://go-review.googlesource.com/64391
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Remove an old comment introduced in golang.org/cl/9073.

Change-Id: I14be27ddfac987f44d839920bc4d02361a576f06
Reviewed-on: https://go-review.googlesource.com/66371
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This change adds the ability to parse
group into email address. The information about
group name and group members is lost for
backwards compatibility. According to this rule address
`Group: Test <text@example.com>;` would be parsed into
`Test <test@example.com>`.

Fixes #22014

Change-Id: I6e804a62f3ede04f555a1b82500b8ca030eeb431
Reviewed-on: https://go-review.googlesource.com/66250
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

On an iPhone 6 running iOS 11, the TestDialerDualStackFDLeak test
started failing with dial durations just above the limit:

FAIL: TestDialerDualStackFDLeak (0.21s)

	dial_test.go:90: got 101.154ms; want <= 95ms

Bump the timeout on iOS.

For the iOS builder.

Change-Id: Id42b471e7cf7d0c84f6e83ed04b395fa1a2d449d
Reviewed-on: https://go-review.googlesource.com/66491
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Attempting to set the SetGID bit on iOS 11 fails with a permission
error. Skip the test.

Change-Id: Idac59750447d668091c44fe7cc5ee178014e0e1d
Reviewed-on: https://go-review.googlesource.com/66490
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

The function isInGoToolsRepo has no use case anymore, so we remove it
with this change.

Change-Id: I71051828eef2e317b83e13f83a14d5f0bc0ec13f
Reviewed-on: https://go-review.googlesource.com/66350Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Also, fix some error messages.

Fixes #22065

Change-Id: Iac05c24b7bb128be3f43b8f2aa180b3957d5ee72
Reviewed-on: https://go-review.googlesource.com/66390
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #21957

Change-Id: I69ef9e257aa2b7b6c4fc4c115e99f8a7f93d8d9c
Reviewed-on: https://go-review.googlesource.com/65150Reviewed-by: Ian Lance Taylor <iant@golang.org>

syscall.Exit and runtime.exit do the same thing.
Why duplicate code?

CL 45115 fixed bug where windows runtime.exit was correct,
but syscall.Exit was broken. So CL 45115 fixed windows
syscall.Exit by calling runtime.exit.

Austin suggested that all OSes should do the same, and
this CL implements his idea.

While making changes, I discovered that nacl syscall.Exit
returned error

func Exit(code int) (err error)

and I changed it into

func Exit(code int)

like all other OSes. I assumed it was a mistake and it
is OK to do because cmd/api does not complain about it.

Also I changed plan9 runtime.exit to accept int32 just
like all other OSes do.

Change-Id: I12f6022ad81406566cf9befcc6edc382eebd413b
Reviewed-on: https://go-review.googlesource.com/66170
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: David du Colombier <0intro@gmail.com>

bytes.IndexByte can be used wherever the second argument to
strings.Index is exactly one byte long, so we do that with this change.

This avoids generating unnecessary string symbols/converison and saves
a few calls to bytes.Index.

Change-Id: If31c775790e01edfece1169e398ad6a754fb4428
Reviewed-on: https://go-review.googlesource.com/66373
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

strings.LastIndexByte was introduced in go1.5 and it can be used
effectively wherever the second argument to strings.LastIndex is
exactly one byte long.

This avoids generating unnecessary string symbols and saves
a few calls to strings.LastIndex.

Change-Id: I7b5679d616197b055cffe6882a8675d24a98b574
Reviewed-on: https://go-review.googlesource.com/66372
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Transport.Proxy is documented as only supporting the http and socks5
schemes. If one tries to use it for https URLs, they end up with a
cryptic error like:

	http: TLS handshake error from [...]: tls: oversized record received with length 20037

This is because Transport simply skips TLS if Proxy is non-nil, since it
knows it doesn't support Proxy with https.

However, that error is very confusing and it can take a while to figure
out what's going on. Instead, error if Proxy is used and it returns an
unsupported scheme.

Updates #19493.

Change-Id: Ia036357011752f45bb9b8282a4ab5e31bc8d1a69
Reviewed-on: https://go-review.googlesource.com/66010
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tom Bergan <tombergan@google.com>

Currently, the priority of checks in (gcTrigger).test() puts the
gcpercent<0 test above gcTriggerCycle, which is used for runtime.GC().
This is an unintentional change from 1.8 and before, where
runtime.GC() triggered a GC even if GOGC=off.

Fix this by rearranging the priority so the gcTriggerCycle test
executes even if gcpercent < 0.

Fixes #22023.

Change-Id: I109328d7b643b6824eb9d79061a9e775f0149575
Reviewed-on: https://go-review.googlesource.com/65994
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>

This permits the program to reliably know that when the Close method
returns, the descriptor has definitely been closed. This matters at
least for listeners.

Fixes #21856
Updates #7970

Change-Id: I1fd0cfd2333649e6e67c6ae956e19fdff3a35a83
Reviewed-on: https://go-review.googlesource.com/66150
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Joe Tsai <joetsai@google.com>

The previous comment of nextSample didn't mention Poisson processes,
which is the reason why it needed to create an exponential
distribution, so it was hard to follow the reasoning for people
not highly familiar with statistics.

Since we're at it, we also make it clear that we are just creating
a random number with exponential distribution by moving the
bulk of the function into a new fastexprand().

No functional changes.

Change-Id: I9c275e87edb3418ee0974257af64c73465028ad7
Reviewed-on: https://go-review.googlesource.com/65657Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

If we have

  y = <int16> (MOVBQSX x)
  z = <int32> (MOVWQSX y)

We used to use this rewrite rule:

(MOVWQSX x:(MOVBQSX _)) -> x

But that resulted in replacing z with a value whose type
is only int16.  Then if z is spilled and restored, it gets
zero extended instead of sign extended.

Instead use the rule

(MOVWQSX (MOVBQSX x)) -> (MOVBQSX x)

The result is has the correct type, so it can be spilled
and restored correctly.  It might mean that a few more extension
ops might not be eliminated, but that's the price for correctness.

Fixes #21963

Change-Id: I6ec82c3d2dbe43cc1fee6fb2bd6b3a72fca3af00
Reviewed-on: https://go-review.googlesource.com/65290Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The previous implementation forced all Unix socket to have a name
strictly shorter than len(sa.raw.Path) to allow a terminating NULL
byte to be added. This requirement does not apply to abstract socket
names under Linux, so for this case we allow the full length.

Fixes #21965

Change-Id: I1d1f58b6b6172d589428c7230cfeae984de78b4b
Reviewed-on: https://go-review.googlesource.com/66190
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

The internal linker doesn't know how to handle multiple TOC sections
in internal linking mode. This used to work because before CL 64793 we
invoked ld -r on multiple objects, and that merged the TOC sections
for us.

Updates #21961

Change-Id: I48260a7195be660016f2f358ebc8cb79652210ab
Reviewed-on: https://go-review.googlesource.com/66270
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

When a MOVDstorezero (8 bytes) is used the offset field
in the instruction must be a multiple of 4. This situation
had been corrected in the rules for other types of stores
but not for the zero case.

This also removes some of the special MOVDstorezero cases since
they can be handled by the general LowerZero case.

Updates made to the ssa test for lowering zero moves to
include cases where the target is not aligned to at least 4.

Fixes #21947

Change-Id: I7cceceb1be4898c77cd3b5e78b58dce0a7e28edd
Reviewed-on: https://go-review.googlesource.com/64970
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Carlos Eduardo Seo <cseo@linux.vnet.ibm.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

internal/poll package assumes that only net sockets use runtime
netpoller on windows. We get memory corruption if other file
handles are passed into runtime poller. Make FD.Init receive
and use useNetpoller argument, so FD.Init caller is explicit
about using runtime netpoller.

Fixes #21172

Change-Id: I60e2bfedf9dda9b341eb7a3e5221035db29f5739
Reviewed-on: https://go-review.googlesource.com/65810Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #21887

Change-Id: I30e8e03ecfb67a2c4deedc2c8436da4c4782136d
Reviewed-on: https://go-review.googlesource.com/63971
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>

The interfaces for io.Reader and io.Writer permit calling Read/Write
with an empty buffer. However, this condition is often not well tested
and can lead to bugs in various implementations of io.Reader and io.Writer.
For example, see #22028 for buggy io.Reader in the bzip2 package.

We reduce the likelihood of hitting these bugs by adjusting
regFileReader.Read and regFileWriter.Write to avoid performing
Read and Write calls when the buffer is known to be empty.

Fixes #22029

Change-Id: Ie4a26be53cf87bc4d2abd951fa005db5871cc75c
Reviewed-on: https://go-review.googlesource.com/66111
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
Reviewed-by: Giovanni Bajo <rasky@develer.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>