runtime.armArch is unused on linux/arm since CL 93637. The new code in
runtime/internal/atomic (added by CL 111315) only checks runtime.goarm.

Change-Id: Ic097ee6750e39abb20f45770a1c7c2d925f02408
Reviewed-on: https://go-review.googlesource.com/c/140077
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

1) Scopes do have a comment field for documentation (debugging output).
   No need to do anything extra.

2) The testcase in expr3.src has ok error messages. Enabled.

Change-Id: Ic1a03bfec0a6a70d876aa6cfb936973abe58fe6c
Reviewed-on: https://go-review.googlesource.com/c/139902Reviewed-by: Alan Donovan <adonovan@google.com>

This work-around is not needed anymore now that method
signatures are type-checked separately from their receiver
base types: no artificial cycles are introduced anymore
and so there is no need to artificially cut them.

Fixes #26854.

Change-Id: I2ef15ceeaa0b486f65f6cdc466d0cf06246c74d7
Reviewed-on: https://go-review.googlesource.com/c/139900Reviewed-by: Alan Donovan <adonovan@google.com>

This work-around is not needed anymore now that method
signatures are type-checked separately from their receiver
base types: no artificial cycles are introduced anymore
and so there is no need to artificially cut them.

Updates #26124.

Change-Id: I9d50171f12dd8977116a5d3f63ac39a06b1cd492
Reviewed-on: https://go-review.googlesource.com/c/139899Reviewed-by: Alan Donovan <adonovan@google.com>

As a side-effect we also get slightly clearer errors for some
pathological cyclic method declarations.

Fixes #23203.
Updates #26854.

Change-Id: I30bd6634ac6be26d3f4ef8c7b32e5c1bf76987dd
Reviewed-on: https://go-review.googlesource.com/c/139897Reviewed-by: Alan Donovan <adonovan@google.com>

Remove assumption that methods associated to concrete (non-interface)
types have a fully set up signature. Such methods are found through
LookupFieldOrMethod or lookupMethod, or indexed method access from
a Named type. Make sure that the method's signature is type-checked
before use in those cases.

(MethodSets also hold methods but the type checker is not using
them but for internal verification. API clients will be using it
after all methods have been type-checked.)

Some functions such as MissingMethod may now have to type-check a
method and for that they need a *Checker. Add helper functions as
necessary to provide the additional (receiver) parameter but permit
it to be nil if the respective functions are invoked through the API
(at which point we know that all methods have a proper signature and
thus we don't need the delayed type-check).

Since all package-level objects eventually are type-checked through
the top-level loop in Checker.packageObjects we are guaranteed that
all methods will be type-checked as well.

Updates #23203.
Updates #26854.

Change-Id: I6e48f0016cefd498aa70b776e84a48215a9042c5
Reviewed-on: https://go-review.googlesource.com/c/139425Reviewed-by: Alan Donovan <adonovan@google.com>

The prior CL prepared go/types for the situation where methods might
not have a type-checked signature when being looked up. The respective
adjustments to recvPtr were not correct (but because so far method
signatures are type-checked in time, the bug didn't manifest itself).

Updates #23203.
Updates #26854.

Change-Id: I796691d11e6aac84396bdef802ad30715755fcc6
Reviewed-on: https://go-review.googlesource.com/c/139721Reviewed-by: Alan Donovan <adonovan@google.com>

The origin tagKey is just dirname if no tags input which will cause
pkgCache missmatch if other imported pkg explicit on GOARCH or GOOS

This CL will add GOOS and GOARCH to tagKey

Fixes #8425
Fixes #21181

Change-Id: Ifc189cf6746d753ad7c7e5bb60621297fc0a4e35
Reviewed-on: https://go-review.googlesource.com/c/138315Reviewed-by: Robert Griesemer <gri@golang.org>

The alloc_m documentation refers to concepts that don't exist (and
maybe never did?). alloc_m is also not the API entry point to span
allocation.

Hence, rewrite the documentation for alloc and alloc_m. While we're
here, document why alloc_m must run on the system stack and replace
alloc_m's hand-implemented system stack check with a go:systemstack
annotation.

Change-Id: I30e263d8e53c2774a6614e1b44df5464838cef09
Reviewed-on: https://go-review.googlesource.com/c/139459
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

.rel symbol type is sym.SELFROSECT, and that makes .rel written
into .rdata section. But .rel stores code - jump table used for
external C functions. So we have to mark whole .rdata section
as executable (IMAGE_SCN_MEM_EXECUTE), because of .rel presence
in it.

Move .rel into .text section, and make .rdata section non executable.

I also had to move code that adjusted the size of .rel symbol
before calling textaddress, otherwise textaddress would not
calculate size of .text section correctly.

Fixes #25926

Change-Id: I4962f5de7b367410154c8709adfcd8472de9ac1a
Reviewed-on: https://go-review.googlesource.com/c/125455
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

On wasm, pcln tables are indexed by "resumption point ID" instead of
by pc offset. When finding a deferreturn call, we must find the
associated resumption point ID for the deferreturn call.

Update #27518
Fixes wasm bug introduced in CL 134637.

Change-Id: I3d178a3f5203a06c0180a1aa2309bfb7f3014f0f
Reviewed-on: https://go-review.googlesource.com/c/139898Reviewed-by: Cherry Zhang <cherryyz@google.com>

This change disables the export-subst and export-ignore attributes when
creating zip files for modules. This is done to prevent the ziphash for
a given repo/revision from differing based on variables such as git
version or size of repo. The full rational for this change is detailed
here:

    https://github.com/golang/go/issues/27153#issuecomment-420763082

Fixes #27153

Change-Id: Ib33f525d91d2581fa0b5d26e70d29620c7e685e9
Reviewed-on: https://go-review.googlesource.com/c/135175
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>

Updates the route package to git rev 68fc911 for:
- 68fc911 re-adjust routing message alignment for FreeBSD 386 emulation
- 4dfa261 fix typos in comments
- ae89d30 avoid unnecessary type conversions

Change-Id: I915e614e464acf85a8fc80f36f05a85a9246bb01
Reviewed-on: https://go-review.googlesource.com/c/139817
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Currently "ADD $0x123456, Rs, Rd" will load pre-stored 0x123456
from the constant pool and use it for the addition. Total 12 bytes
are cost. And so does SUB.

This CL breaks it to "ADD 0x123000, Rs, Rd" + "ADD 0x000456, Rd, Rd".
Both "0x123000" and "0x000456" can be directly encoded into the
instruction binary code. So 4 bytes are saved.

1. The total size of pkg/android_arm64 decreases about 0.3KB.

2. The go1 benchmark show little regression (excluding noise).

name                     old time/op    new time/op    delta
BinaryTree17-4              15.9s ± 0%     15.9s ± 1%  +0.10%  (p=0.044 n=29+29)
Fannkuch11-4                8.72s ± 0%     8.75s ± 0%  +0.34%  (p=0.000 n=30+24)
FmtFprintfEmpty-4           173ns ± 0%     173ns ± 0%    ~     (all equal)
FmtFprintfString-4          368ns ± 0%     368ns ± 0%    ~     (p=0.593 n=30+30)
FmtFprintfInt-4             417ns ± 0%     417ns ± 0%    ~     (all equal)
FmtFprintfIntInt-4          673ns ± 0%     661ns ± 1%  -1.70%  (p=0.000 n=30+30)
FmtFprintfPrefixedInt-4     805ns ± 0%     805ns ± 0%  +0.10%  (p=0.011 n=30+30)
FmtFprintfFloat-4          1.09µs ± 0%    1.09µs ± 0%    ~     (p=0.125 n=30+29)
FmtManyArgs-4              2.68µs ± 0%    2.68µs ± 0%  +0.07%  (p=0.004 n=30+30)
GobDecode-4                32.9ms ± 0%    33.2ms ± 1%  +1.07%  (p=0.000 n=29+29)
GobEncode-4                29.5ms ± 0%    29.6ms ± 0%  +0.26%  (p=0.000 n=28+28)
Gzip-4                      1.38s ± 1%     1.35s ± 3%  -1.94%  (p=0.000 n=28+30)
Gunzip-4                    139ms ± 0%     139ms ± 0%  +0.10%  (p=0.000 n=28+29)
HTTPClientServer-4          745µs ± 5%     742µs ± 3%    ~     (p=0.405 n=28+29)
JSONEncode-4               49.5ms ± 1%    49.9ms ± 0%  +0.89%  (p=0.000 n=30+30)
JSONDecode-4                264ms ± 1%     264ms ± 0%  +0.25%  (p=0.001 n=30+30)
Mandelbrot200-4            16.6ms ± 0%    16.6ms ± 0%    ~     (p=0.507 n=29+29)
GoParse-4                  15.9ms ± 0%    16.0ms ± 1%  +0.91%  (p=0.002 n=23+30)
RegexpMatchEasy0_32-4       379ns ± 0%     379ns ± 0%    ~     (all equal)
RegexpMatchEasy0_1K-4      1.31µs ± 0%    1.31µs ± 0%  +0.09%  (p=0.008 n=27+30)
RegexpMatchEasy1_32-4       357ns ± 0%     358ns ± 0%  +0.28%  (p=0.000 n=28+29)
RegexpMatchEasy1_1K-4      2.04µs ± 0%    2.04µs ± 0%    ~     (p=0.850 n=30+30)
RegexpMatchMedium_32-4      587ns ± 0%     589ns ± 0%  +0.33%  (p=0.000 n=30+30)
RegexpMatchMedium_1K-4      162µs ± 0%     163µs ± 0%    ~     (p=0.351 n=30+29)
RegexpMatchHard_32-4       9.54µs ± 0%    9.60µs ± 0%  +0.59%  (p=0.000 n=28+30)
RegexpMatchHard_1K-4        287µs ± 0%     287µs ± 0%  +0.11%  (p=0.000 n=26+29)
Revcomp-4                   2.50s ± 0%     2.50s ± 0%  -0.13%  (p=0.012 n=28+27)
Template-4                  312ms ± 1%     312ms ± 1%  +0.20%  (p=0.015 n=27+30)
TimeParse-4                1.68µs ± 0%    1.68µs ± 0%  -0.35%  (p=0.000 n=30+30)
TimeFormat-4               1.66µs ± 0%    1.64µs ± 0%  -1.20%  (p=0.000 n=25+29)
[Geo mean]                  246µs          246µs       -0.00%

name                     old speed      new speed      delta
GobDecode-4              23.3MB/s ± 0%  23.1MB/s ± 1%  -1.05%  (p=0.000 n=29+29)
GobEncode-4              26.0MB/s ± 0%  25.9MB/s ± 0%  -0.25%  (p=0.000 n=29+28)
Gzip-4                   14.1MB/s ± 1%  14.4MB/s ± 3%  +1.94%  (p=0.000 n=27+30)
Gunzip-4                  139MB/s ± 0%   139MB/s ± 0%  -0.10%  (p=0.000 n=28+29)
JSONEncode-4             39.2MB/s ± 1%  38.9MB/s ± 0%  -0.88%  (p=0.000 n=30+30)
JSONDecode-4             7.37MB/s ± 0%  7.35MB/s ± 0%  -0.26%  (p=0.001 n=30+30)
GoParse-4                3.65MB/s ± 0%  3.62MB/s ± 1%  -0.86%  (p=0.001 n=23+30)
RegexpMatchEasy0_32-4    84.3MB/s ± 0%  84.3MB/s ± 0%    ~     (p=0.126 n=27+26)
RegexpMatchEasy0_1K-4     784MB/s ± 0%   783MB/s ± 0%  -0.10%  (p=0.003 n=27+30)
RegexpMatchEasy1_32-4    89.5MB/s ± 0%  89.3MB/s ± 0%  -0.20%  (p=0.000 n=27+29)
RegexpMatchEasy1_1K-4     502MB/s ± 0%   502MB/s ± 0%    ~     (p=0.858 n=30+28)
RegexpMatchMedium_32-4   1.70MB/s ± 0%  1.70MB/s ± 0%  -0.25%  (p=0.000 n=30+30)
RegexpMatchMedium_1K-4   6.30MB/s ± 0%  6.30MB/s ± 0%    ~     (all equal)
RegexpMatchHard_32-4     3.35MB/s ± 0%  3.33MB/s ± 0%  -0.47%  (p=0.000 n=30+30)
RegexpMatchHard_1K-4     3.57MB/s ± 0%  3.56MB/s ± 0%  -0.20%  (p=0.000 n=27+30)
Revcomp-4                 102MB/s ± 0%   102MB/s ± 0%  +0.14%  (p=0.008 n=28+28)
Template-4               6.23MB/s ± 0%  6.21MB/s ± 1%  -0.21%  (p=0.009 n=21+30)
[Geo mean]               24.1MB/s       24.0MB/s       -0.16%

Change-Id: Ifcef3edb667540e2d86e586c23afcfbc2cf1340b
Reviewed-on: https://go-review.googlesource.com/c/134536
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

The TestLldbPython test is known to fail with very old lldb releases
(3.8 and older). Skip the test when the lldb found on the system is
too old.

Fixes #22299

Change-Id: I8f78d6c0d995118f806dae87f3f04a9726473116
Reviewed-on: https://go-review.googlesource.com/c/139397Reviewed-by: Ian Lance Taylor <iant@golang.org>

It requires a DLL that's not available on windows/arm apparently.

Fixes #27904

Change-Id: I082a273f62976b7184636c6aeca6201a7871d238
Reviewed-on: https://go-review.googlesource.com/c/139720
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Katie Hockman <katie@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

name     old time/op  new time/op  delta
PowInt   55.7ns ± 1%  53.4ns ± 2%  -4.15%  (p=0.000 n=9+9)
PowFrac   133ns ± 1%   133ns ± 2%    ~     (p=0.587 n=8+9)

Change-Id: Ica0f4c2cbd554f2195c6d1762ed26742ff8e3924
Reviewed-on: https://go-review.googlesource.com/c/85375Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

goos: linux
goarch: amd64
pkg: math

name  old time/op  new time/op  delta
Mod   64.7ns ± 2%  63.7ns ± 2%  -1.52%  (p=0.003 n=8+10)

Change-Id: I851bec0fd6c223dab73e4a680b7393d49e81a0e8
Reviewed-on: https://go-review.googlesource.com/c/85095Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I69582662aeee7344226856c24907516ddfc92f60
Reviewed-on: https://go-review.googlesource.com/c/139717
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Elias Naur <elias.naur@gmail.com>

Currently the table of arena sizes mixes the number of entries in the
L1 with the size of the L2. While the size of the L2 is important,
this makes it hard to see what's actually going on because there's an
implicit factor of sys.PtrSize.

This changes the L2 column to say both the number of entries and the
size that results in. This should hopefully make the relations between
the columns of the table clearer, since they can now be plugged
directly into the given formula.

Change-Id: Ie677adaef763b893a2f620bd4fc3b8db314b3a1e
Reviewed-on: https://go-review.googlesource.com/c/139697Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

mheap_.treapalloc.alloc() already returns a zeroed treapNode. Don't
bother re-zeroing all of the fields.

Change-Id: Iea317040fbb72dfe5ef1e2c56c287680b065f2d9
Reviewed-on: https://go-review.googlesource.com/c/139460
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This fixes the build for long-running tests after CL 139338

Change-Id: Ib8adfa785d41c736188e2ff7e14125de045b96b9
Reviewed-on: https://go-review.googlesource.com/c/139637
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

LookupFieldOrMethod needs to know if a method receiver is a pointer
type. Until now this was computed from the the method signature's
receiver, which required the method signature to be type-checked.
Furthermore, it required the receiver to be set before the method
signature was fully type-checked in some cases (see issue #6638).

This CL remembers this property during object resolution, when we
know it from the source.

With this CL, method signatures don't need to be type-checked before
they can be looked up; this is a first step towards separating
type checking of types and type-checking of associated methods.

Updates #23203.
Updates #26854.

Change-Id: Ie3eb7976e8fe8176ea1b284fa7471a4b7000f80b
Reviewed-on: https://go-review.googlesource.com/c/139422
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>

Change-Id: I0490098a7235458c5aede1135426a9f19f8584a7
Reviewed-on: https://go-review.googlesource.com/c/76312
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

In preparation for followup CL merging TPTR32 and TPTR64, move TPTR32
from the small-types fast path to the generic 64-bit fallback code so
that it's in the same case clause as TPTR64.

This should be safe, but theoretically it could change semantics
because TPTR32 used to always be assumed to be "small", whereas now it
will only be considered small for values less than 1<<31.

This change is done in a separate CL so that it's more easily
identified by git bisection in case it does introduce regressions.

Change-Id: I6c7bb253d4e4d95c530a6e05a1147905674b55ca
Reviewed-on: https://go-review.googlesource.com/c/139517
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

Change-Id: Ie4bab0b74d5a4e1aecd8501a48176b2e9a3d8c42
Reviewed-on: https://go-review.googlesource.com/c/76311
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>

As pointed out in https://github.com/golang/go/issues/26463,
HOME (or equivalent) environment variable (rather than the
value obtained by parsing /etc/passwd or the like) should be
used to obtain user's home directory.

Since commit fa1a49aa there's a method to obtain
user's home directory -- use it here.

Change-Id: I852fbb24249bcfe08f3874fae6e7b9d01d869190
Reviewed-on: https://go-review.googlesource.com/c/139426Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #13491

Change-Id: Ic0525d8ee90f47d0d23c1485919aee13d2400494
Reviewed-on: https://go-review.googlesource.com/c/139537
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: Id21cdce35963dcdb96cc06252170590224c5aa17
GitHub-Last-Rev: 429dad0ceba123415af308179d0d2aa9773e6323
GitHub-Pull-Request: golang/go#28000
Reviewed-on: https://go-review.googlesource.com/c/139424Reviewed-by: Ian Lance Taylor <iant@golang.org>

This commit makes syscall on js/wasm use the asynchronous variants
of functions in Node.js' fs module. This enables concurrency
and allows the API of the fs module to be implemented with an
alternative backend that only supports asynchronous operations.

Updates #26051.

Change-Id: Ibe1dcc988469fc11c3b8d8d49de439c12ddaafce
Reviewed-on: https://go-review.googlesource.com/c/137236
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #22614

Change-Id: I220afbaaeab4dec6d59eeeef12107234a77f1587
Reviewed-on: https://go-review.googlesource.com/c/139419Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #27990

Change-Id: I0f09fc6f68cec770b1c26eed2315afbf6bf6cd4d
GitHub-Last-Rev: 8486e6d5019c6c21b10e5fcf10a2727cf2705174
GitHub-Pull-Request: golang/go#27991
Reviewed-on: https://go-review.googlesource.com/c/139417
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

The following adds support for load and store instructions
with index registers, and adds rules to take advantage of
those instructions.

Examples of improvements:

crypto/rc4:
name     old time/op   new time/op   delta
RC4_128    445ns ± 0%    404ns ± 0%   -9.21%  (p=0.029 n=4+4)
RC4_1K    3.46µs ± 0%   3.13µs ± 0%   -9.29%  (p=0.029 n=4+4)
RC4_8K    27.0µs ± 0%   24.7µs ± 0%   -8.83%  (p=0.029 n=4+4)

crypto/des:
name         old time/op    new time/op    delta
Encrypt         276ns ± 0%     264ns ± 0%  -4.35%  (p=0.029 n=4+4)
Decrypt         278ns ± 0%     263ns ± 0%  -5.40%  (p=0.029 n=4+4)
TDESEncrypt     683ns ± 0%     645ns ± 0%  -5.56%  (p=0.029 n=4+4)
TDESDecrypt     684ns ± 0%     641ns ± 0%  -6.29%  (p=0.029 n=4+4)

crypto/sha1:
name          old time/op    new time/op    delta
Hash8Bytes       661ns ± 0%     635ns ± 0%  -3.93%  (p=1.000 n=1+1)
Hash320Bytes    2.70µs ± 0%    2.56µs ± 0%  -5.26%  (p=1.000 n=1+1)
Hash1K          7.14µs ± 0%    6.78µs ± 0%  -5.03%  (p=1.000 n=1+1)
Hash8K          52.1µs ± 0%    49.4µs ± 0%  -5.14%  (p=1.000 n=1+1)

Change-Id: I03810e90fcc20029975a323f06bfa086c973c2b0
Reviewed-on: https://go-review.googlesource.com/c/135975
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Munday <mike.munday@ibm.com>

Fixes #26463

Change-Id: Iaef1c7456ffaeadeead6027a37d09c44a3d05bd5
Reviewed-on: https://go-review.googlesource.com/c/139418Reviewed-by: Ian Lance Taylor <iant@golang.org>

This commit adds AIX operating system to internal/syscall package for ppc64
architecture.

Updates: #25893

Change-Id: I5c3a9d4403ca170a7e894e06e68b83387d09b816
Reviewed-on: https://go-review.googlesource.com/c/138718
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

When an invalid UTF-8 byte sequence is decoded in a range loop over a string
a utf8.RuneError rune is returned. This is not distinguishable from decoding
the valid '\uFFFD' sequence representing utf8.RuneError from a string without
further checks within the range loop.

The previous Map code did not do any extra checks and would thereby not map
invalid UTF-8 byte sequences correctly when those were mapping to utf8.RuneError.

Fix this by adding the extra checks necessary to distinguish the decoding
of invalid utf8 byte sequences from decoding the sequence for utf8.RuneError
when the mapping of a rune is utf8.RuneError.

This fix does not result in a measureable performance regression:
name                old time/op  new time/op  delta
ByteByteMap         1.05µs ± 3%  1.03µs ± 3%   ~     (p=0.118 n=10+10)
Map/identity/ASCII   169ns ± 2%   170ns ± 1%   ~     (p=0.501 n=9+10)
Map/identity/Greek   298ns ± 1%   303ns ± 4%   ~     (p=0.338 n=10+10)
Map/change/ASCII     323ns ± 3%   325ns ± 4%   ~     (p=0.679 n=8+10)
Map/change/Greek     628ns ± 5%   635ns ± 1%   ~     (p=0.460 n=10+9)
MapNoChanges         120ns ± 4%   119ns ± 1%   ~     (p=0.496 n=10+9)

Fixes #26305

Change-Id: I70e99fa244983c5040756fa4549ac1e8cb6022c3
Reviewed-on: https://go-review.googlesource.com/c/131495Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This commit adds AIX operating system to internal/poll package for ppc64
architecture.

Updates: #25893

Change-Id: I9b1da9255012de58f16547c1b18f8840485da170
Reviewed-on: https://go-review.googlesource.com/c/138717
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This commit adds AIX operating system to runtime package for ppc64
architecture.

Only new files and minor changes are in this commit. Others
modifications in files like asm_ppc64.s  will be in separate commits.

Updates: #25893

Change-Id: I9c5e073f5f3debb43b004ad1167694a5afd31cfd
Reviewed-on: https://go-review.googlesource.com/c/138716
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Currently, the Windows profile loop isn't robust against racing with
unminit. For example,

T1 is running profileloop1, T2 is another thread
T1: thread := atomic.Loaduintptr(&T2.thread)
T2: calls unminit, which does CloseHandle(T2.thread)
T1: attempts to suspends T2

In this case the SuspendThread will fail, but currently we ignore this
failure and forge ahead, which will cause further failures and
probably bad profile data.

Handle this race by defending against SuspendThread failing. If
SuspendThread succeeds, then we know the thread is no longer going
anywhere.

Change-Id: I4726553239b17f05ca07a0cf7df49631e0cb550d
Reviewed-on: https://go-review.googlesource.com/c/129685
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

The debug call injection tests will freeze when run under a debugger
because they depend on catching SIGTRAP, which is usually swallowed by
a debugger.

Change-Id: If6b86ca279b0489182990dd513444ca3062973f1
Reviewed-on: https://go-review.googlesource.com/c/139437
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>