If $WORK happens to contain the string that a stdout/stderr/grep
command is searching for, a negative grep command will fail incorrectly.
Fixes#27170Fixes#27221
Change-Id: I84454d3c42360fe3295c7235d388381525eb85b4
Reviewed-on: https://go-review.googlesource.com/131398
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
...and add the vet failures to the vet whitelist.
Change-Id: Idcf4289f39dda561c85f3b0afe396e5299e6495f
Reviewed-on: https://go-review.googlesource.com/127995
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
If an object is allocated as part of a tinyalloc, then other live
objects in the same tinyalloc chunk keep the finalizer from being run,
even if the object that has the finalizer is dead.
Make sure the object we're setting the finalizer on is big enough
to not trigger tinyalloc allocation.
Fixes#26857
Update #21717
Change-Id: I56ad8679426283237ebff20a0da6c9cf64eb1c27
Reviewed-on: https://go-review.googlesource.com/128475
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Before this CL we would build&run each test file individually.
Building the test takes most of the time, a significant fraction of a
second. Running the tests are really fast.
After this CL, we build all the tests at once, then run each
individually. We only have to run the compiler&linker once (or twice,
for softfloat architectures) instead of once per test.
While we're here, organize these tests to fit a bit more into the
standard testing framework.
This is just the organizational CL that changes the testing framework
and migrates 2 tests. Future tests will follow.
R=go1.12
Update #26469
Change-Id: I1a1e7338c054b51f0c1c4c539d48d3d046b08b7d
Reviewed-on: https://go-review.googlesource.com/126995
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
This change adds a new column, AST IR. That column contains
nodes for a function specified in $GOSSAFUNC.
Also this CL enables horizontal scrolling of sources and AST columns.
Fixes#26662
Change-Id: I3fba39fd998bb05e9c93038e8ec2384c69613b24
Reviewed-on: https://go-review.googlesource.com/126858
Run-TryBot: Yury Smolsky <yury@smolsky.by>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The sigInitIgnored function can be called by initsig before a shared
library is initialized, before the runtime is initialized.
Fixes#27183
Change-Id: I7073767938fc011879d47ea951d63a14d1cce878
Reviewed-on: https://go-review.googlesource.com/131277
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Add an "offset_" prefix to all cpu feature variable offset constants to
signify that they are not boolean cpu feature variables.
Remove _ from offset constant names.
Change-Id: I6e22a79ebcbe6e2ae54c4ac8764f9260bb3223ff
Reviewed-on: https://go-review.googlesource.com/131215
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
sys here is runtime/internal/sys.
Replace uses of sys.CacheLineSize for padding by
cpu.CacheLinePad or cpu.CacheLinePadSize.
Replace other uses of sys.CacheLineSize by cpu.CacheLineSize.
Remove now unused sys.CacheLineSize.
Updates #25203
Change-Id: I1daf410fe8f6c0493471c2ceccb9ca0a5a75ed8f
Reviewed-on: https://go-review.googlesource.com/126601
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Use a separate func, which needs less indentation and can use returns
instead of labelled breaks. We can also give the types better names, and
we don't have to repeat the calls to conv and mkcall.
Passes toolstash -cmp on std cmd.
Change-Id: I1071c170fa729562d70093a09b7dea003c5fe26e
Reviewed-on: https://go-review.googlesource.com/130075
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
The new constant CacheLinePadSize can be used to compute best effort
alignment of structs to cache lines.
e.g. the runtime can use this in the locktab definition:
var locktab [57]struct {
l spinlock
pad [cpu.CacheLinePadSize - unsafe.Sizeof(spinlock{})]byte
}
Change-Id: I86f6fbfc5ee7436f742776a7d4a99a1d54ffccc8
Reviewed-on: https://go-review.googlesource.com/131237
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
A timezone with a zero offset from UTC and without a three-letter
abbreviation will have a numeric name in timestamps: "+00".
There are currently two of them:
$ zdump Atlantic/Azores America/Scoresbysund
Atlantic/Azores Wed Aug 22 09:01:05 2018 +00
America/Scoresbysund Wed Aug 22 09:01:05 2018 +00
These two timestamp are rejected by Parse, since it doesn't allow for
zero offsets:
parsing time "Wed Aug 22 09:01:05 2018 +00": extra text: +00
This change modifies Parse to accept a +00 offset in numeric timezone
names.
As side effect of this change, Parse also now accepts "GMT+00". It was
explicitely disallowed (with a unit test ensuring it got rejected),
but the restriction seems incorrect.
DATE(1), for example, allows it:
$ date --debug --date="2009-01-02 03:04:05 GMT+00"
date: parsed date part: (Y-M-D) 2009-01-02
date: parsed time part: 03:04:05
date: parsed zone part: UTC+00
date: input timezone: parsed date/time string (+00)
date: using specified time as starting value: '03:04:05'
date: starting date/time: '(Y-M-D) 2009-01-02 03:04:05 TZ=+00'
date: '(Y-M-D) 2009-01-02 03:04:05 TZ=+00' = 1230865445 epoch-seconds
date: timezone: system default
date: final: 1230865445.000000000 (epoch-seconds)
date: final: (Y-M-D) 2009-01-02 03:04:05 (UTC)
date: final: (Y-M-D) 2009-01-02 04:04:05 (UTC+01)
Fri 2 Jan 04:04:05 CET 2009
This fixes 2 of 17 time.Parse() failures listed in Issue #26032.
Updates #26032
Change-Id: I01cd067044371322b7bb1dae452fb3c758ed3cc2
Reviewed-on: https://go-review.googlesource.com/130696
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Follow the implementation used by the other BSDs ith os.Pipe and
syscall.forkExecPipe consisting of a single syscall instead of three.
Change-Id: I602187672f244cbd8faaa3397904d71d15452d9f
Reviewed-on: https://go-review.googlesource.com/130996
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Assumes mandatory VFP and VFPv3 support to be present by default
but not IDIVA if AT_HWCAP is not available.
Adds GODEBUGCPU options to disable the use of code paths in the runtime
that use hardware support for division.
Change-Id: Ida02311bd9b9701de3fc120697e69445bf6c0853
Reviewed-on: https://go-review.googlesource.com/114826
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The new slice created in growslice is cleared during malloc for
element types containing pointers and therefore can only contain
nil pointers. This change avoids executing write barriers for these
nil pointers by adding and using a special bulkBarrierPreWriteSrcOnly
function that does not enqueue pointers to slots in dst to the write
barrier buffer.
Change-Id: If9b18248bfeeb6a874b0132d19520adea593bfc4
Reviewed-on: https://go-review.googlesource.com/115996
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Using internal/cpu variables has the benefit of avoiding false sharing
(as those are padded) and allows memory and cache usage for these variables
to be shared by multiple packages.
Change-Id: I2bf68d03091bf52b466cf689230d5d25d5950037
Reviewed-on: https://go-review.googlesource.com/126599
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Just open-code the fcntl syscall instead of relying on the obscurity of
go:linkname.
Change-Id: I3e4ec9db6539e016f56667d7b8b87aa37671d0e7
Reviewed-on: https://go-review.googlesource.com/130736
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This message has no format specifiers and no trailing newline.
It should use Println for consistency with other examples.
Change-Id: I49bd1652f9449fcbdd79c6b689c123090972aab3
Reviewed-on: https://go-review.googlesource.com/127836
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
- add comments with builtin function signatures that are instantiated
- use Nodes type from the beginning instead of
[]*Node with a later conversion to Nodes
- use conv(x, y) helper function instead of nod(OCONV, x, y)
- factor out repeated calls to Type.Elem()
This makes the function style similar to newer functions like extendslice.
passes toolstash -cmp
Change-Id: Iedab191af9e0884fb6762c9c168430c1d2246979
Reviewed-on: https://go-review.googlesource.com/112598
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
A signed right shift before an unsigned right shift by register width-1
(extracts the sign bit) is superflous.
trigger counts during ./make.bash
0 (Rsh8U (Rsh8 x _) 7 ) -> (Rsh8U x 7 )
0 (Rsh16U (Rsh16 x _) 15 ) -> (Rsh16U x 15)
2 (Rsh32U (Rsh32 x _) 31 ) -> (Rsh32U x 31)
251 (Rsh64U (Rsh64 x _) 63 ) -> (Rsh64U x 63)
Changes the instructions generated on AMD64 for x / 2 where
x is a signed integer from:
MOVQ AX, CX
SARQ $63, AX
SHRQ $63, AX
ADDQ CX, AX
SARQ $1, AX
to:
MOVQ AX, CX
SHRQ $63, AX
ADDQ CX, AX
SARQ $1, AX
Change-Id: I86321ae8fc9dc24b8fa9eb80aa5c7299eff8c9dc
Reviewed-on: https://go-review.googlesource.com/115956
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
ARM64 also supports float point LDP(load pair) & STP (store pair).
The CL adds implementation and corresponding test cases for
FLDPD/FLDPS/FSTPD/FSTPS.
Change-Id: I45f112012a4e097bfaf023d029b36e6cbc7a5859
Reviewed-on: https://go-review.googlesource.com/125438
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
The wiki page has recently been created, and at this time it's
just a stub. It's expected that support for WebAssembly will be
evolving over time, and the wiki page can be kept updated with
helpful information, how to get started, tips and tricks, etc.
Use present tense because it's expected that there will be more
general information added by the time Go 1.11 release happens.
Also add link to https://webassembly.org/ in first paragraph.
Change-Id: I139c2dcec8f0d7fd89401df38a3e12960946693f
Reviewed-on: https://go-review.googlesource.com/131078
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
gentraceback handles system stack transitions, but only when they're
done by systemstack(). Handle morestack() too.
I tried to do this generically but systemstack and morestack are
actually *very* different functions. Most notably, systemstack returns
"normally", just messes with $sp along the way. morestack never
returns at all -- it calls newstack, and newstack then jumps both
stacks and functions back to whoever called morestack. I couldn't
think of a way to handle both of them generically. So don't.
The current implementation does not include systemstack on the generated
traceback. That's partly because I don't know how to find its stack frame
reliably, and partly because the current structure of the code wants to
do the transition before the call, not after. If we're willing to
assume that morestack's stack frame is 0 size, this could probably be
fixed.
For posterity's sake, alternatives tried:
- Have morestack put a dummy function into schedbuf, like systemstack
does. This actually worked (see patchset 1) but more by a series of
coincidences than by deliberate design. The biggest coincidence was that
because morestack_switch was a RET and its stack was 0 size, it actually
worked to jump back to it at the end of newstack -- it would just return
to the caller of morestack. Way too subtle for me, and also a little
slower than just jumping directly.
- Put morestack's PC and SP into schedbuf, so that gentraceback could
treat it like a normal function except for the changing SP. This was a
terrible idea and caused newstack to reenter morestack in a completely
unreasonable state.
To make testing possible I did a small redesign of testCPUProfile to
take a callback that defines how to check if the conditions pass to it
are satisfied. This seemed better than making the syntax of the "need"
strings even more complicated.
Updates #25943
Change-Id: I9271a30a976f80a093a3d4d1c7e9ec226faf74b4
Reviewed-on: https://go-review.googlesource.com/126795
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
gentraceback gets the currently running g to do some sanity checks, but
should use gp everywhere to do its actual work. Some noncritical checks
later accidentally used g instead of gp. This seems like it could be a
problem in many different contexts, but I noticed in Windows profiling,
where profilem calls gentraceback on a goroutine from a different
thread.
Change-Id: I3da27a43e833b257f6411ee6893bdece45a9323f
Reviewed-on: https://go-review.googlesource.com/128895
Run-TryBot: Heschi Kreinick <heschi@google.com>
Reviewed-by: Austin Clements <austin@google.com>
This turns
panic: function name is not a valid identifier
into
panic: function name "" is not a valid identifier
and also makes it consistent with the func signature check.
This CL also makes the testBadFuncName func a test helper.
Change-Id: Id967cb61ac28228de81e1cd76a39f5195a5ebd11
Reviewed-on: https://go-review.googlesource.com/130998
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
We can no longer use the field's position for the duplicate field tag
warning - since we now check embedded tags, the positions may belong to
copmletely different packages.
Instead, keep track of the lowest field that's still part of the
top-level struct type that we are checking.
Finally, be careful to not repeat the independent struct field warnings
when checking fields again because they are embedded into another
struct. To do this, separate the duplicate tag value logic into a func
that recurses into embedded fields on a per-encoding basis.
Fixes#25593.
Change-Id: I3bd6e01306d8ec63c0314d25e3136d5e067a9517
Reviewed-on: https://go-review.googlesource.com/115677
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>
Like the conv helper function but for creating OCONVNOP nodes
instead of OCONV nodes.
passes toolstash -cmp
Change-Id: Ib93ffe66590ebaa2b4fa552c81f1a2902e789d8e
Reviewed-on: https://go-review.googlesource.com/112597
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
This CL adds the source code of all inlined functions
into the function specified in $GOSSAFUNC.
The code is appended to the sources column of ssa.html.
ssaDumpInlined is populated with references to inlined functions.
Then it is used for dumping the sources in buildssa.
The source columns contains code in following order:
target function, inlined functions sorted by filename, lineno.
Fixes#25904
Change-Id: I4f6d4834376f1efdfda1f968a5335c0543ed36bc
Reviewed-on: https://go-review.googlesource.com/126606
Run-TryBot: Yury Smolsky <yury@smolsky.by>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
This CL exports the Func.Endlineno value for inlineable functions.
It is needed to grab the source code of an imported function
inlined into the function specified in $GOSSAFUNC.
See CL 126606 for details.
Updates #25904
Change-Id: I1e259e20445e4109b4621a95abb5bde1be457af1
Reviewed-on: https://go-review.googlesource.com/126605
Run-TryBot: Yury Smolsky <yury@smolsky.by>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Since we print almost everything to ssa.html in the GOSSAFUNC mode,
there is a need to stop spamming stdout when user just wants to see
ssa.html.
This changes cleans output of the GOSSAFUNC debug mode.
To enable the dump of the debug data to stdout, one must
put suffix + after the function name like that:
GOSSAFUNC=Foo+
Otherwise gc will not print the IR and ASM to stdout after each phase.
AST IR is still sent to stdout because it is not included
into ssa.html. It will be fixed in a separate change.
The change adds printing out the full path to the ssa.html file.
Updates #25942
Change-Id: I711e145e05f0443c7df5459ca528dced273a62ee
Reviewed-on: https://go-review.googlesource.com/126603
Run-TryBot: Yury Smolsky <yury@smolsky.by>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The current implementation removes all of the optimization flags from
the compiler.
Added the -O0 optimization flag after the removal loop, so go can
compile cgo on every OS consistently.
Fixes#26487
Change-Id: Ia98bca90def186dfe10f50b1787c2f40d85533da
Reviewed-on: https://go-review.googlesource.com/127755
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The divLarge code contained "todo"s about avoiding alias
and clear calls in the initialization of variables. By
rearranging the order of initialization and always using
an auxiliary variable for the shifted divisor, all of these
calls can be safely avoided. On average, normalizing
the divisor (shift>0) is required 31/32 or 63/64 of the
time. If one always performs the shift into an auxiliary
variable first, this avoids the need to check for aliasing of
vIn in the output variables u and z. The remainder u is
initialized via a left shift of uIn and thus needs no
alias check against uIn. Since uIn and vIn were both used,
z needs no alias checks except against u which is used for
storage of the remainder. This change has a minimal impact
on performance (see below), but cleans up the initialization
code and eliminates the "todo"s.
name old time/op new time/op delta
Div/20/10-4 86.7ns ± 6% 85.7ns ± 5% ~ (p=0.841 n=5+5)
Div/200/100-4 523ns ± 5% 502ns ± 3% -4.13% (p=0.024 n=5+5)
Div/2000/1000-4 2.55µs ± 3% 2.59µs ± 5% ~ (p=0.548 n=5+5)
Div/20000/10000-4 80.4µs ± 4% 80.0µs ± 2% ~ (p=1.000 n=5+5)
Div/200000/100000-4 6.43ms ± 6% 6.35ms ± 4% ~ (p=0.548 n=5+5)
Fixes#22928
Change-Id: I30d8498ef1cf8b69b0f827165c517bc25a5c32d7
Reviewed-on: https://go-review.googlesource.com/130775
Reviewed-by: Robert Griesemer <gri@golang.org>
Use defined named constants instead of 0 literal in comparisons.
Found using https://go-critic.github.io/overview.html#namedConst-ref
Change-Id: Ic075cece248f6e51db0b3d9d9eaba7d6409c9eef
Reviewed-on: https://go-review.googlesource.com/123376
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
When this code was introduced, there were no R_MIPS, R_PPC64 and
R_390 and build would fail with this code uncommented.
Now we have those.
Change-Id: I18a54eaa250db12e293f8e4d1f080f1dd2e66a4f
Reviewed-on: https://go-review.googlesource.com/122896
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
As reported in #26650 and also cautioned on the man page
for fsync on OS X, fsync doesn't properly flush content
to permanent storage, and might cause corruption of data if
the OS crashes or if the drive loses power. Thus it is recommended
to use the F_FULLFSYNC fcntl, which flushes all buffered data to
permanent storage and is important for applications such as
databases that require a strict ordering of writes.
Also added a note in syscall_darwin.go that syscall.Fsync is
not invoked for os.File.Sync.
Fixes#26650.
Change-Id: Idecd9adbbdd640b9c5b02e73b60ed254c98b48b6
Reviewed-on: https://go-review.googlesource.com/130676
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This comment has been the source of much confusion and broken dreams. We
can add it back if a tool ever gets released.
Updates #16742
Change-Id: I4b9c179b7c60274e6ff1bcb607b82029dd9a893f
Reviewed-on: https://go-review.googlesource.com/130876
Reviewed-by: Matt Layher <mdlayher@gmail.com>
Reviewed-by: Alan Donovan <adonovan@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
If two goroutines are racing on a map, one of them will exit
cleanly, clearing the hashWriting bit, and the other will
likely notice and panic. If we use XOR instead of OR to
set the bit in the first place, even numbers of racers will
hopefully all see the bit cleared and panic simultaneously,
giving the full set of available stacks. If a third racer
sneaks in, we are no worse than the current code, and
the generated code should be no more expensive.
In practice, this catches most racing goroutines even in
very tight races. See the demonstration program posted
on https://github.com/golang/go/issues/26703 for an example.
Fixes#26703
Change-Id: Idad17841a3127c24bd0a659b754734f70e307434
Reviewed-on: https://go-review.googlesource.com/126936
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
