This is a simple tweak to allow a bit more mid-stack inlining.
In cases like this:
func f() {
g()
}
We'd really like to inline f into its callers. It can't hurt.
We implement this optimization by making calls a bit cheaper, enough
to afford a single call in the function body, but not 2.
The remaining budget allows for some argument modification, or perhaps
a wrapping conditional:
func f(x int) {
g(x, 0)
}
func f(x int) {
if x > 0 {
g()
}
}
Update #19348
Change-Id: Ifb1ea0dd1db216c3fd5c453c31c3355561fe406f
Reviewed-on: https://go-review.googlesource.com/c/147361
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: David Chase <drchase@google.com>
This commit skips tests which aren't yet supported on AIX.
nosplit.go is disabled because stackGuardMultiplier is increased for
syscalls.
Change-Id: Ib5ff9a4539c7646bcb6caee159f105ff8a160ad7
Reviewed-on: https://go-review.googlesource.com/c/146939
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
As discussed in golang.org/cl/28499:
Only test that all expected variables are listed in 'info locals' since
different versions of gdb print variables in different order and with
differing amount of information and formats.
Fixes#28499
Change-Id: I76627351170b5fdf2bf8cbf143e54f628b45dc4e
Reviewed-on: https://go-review.googlesource.com/c/146598
Reviewed-by: Heschi Kreinick <heschi@google.com>
Only return a pointer p to the new slices backing array from makeslice.
Makeslice callers then construct sliceheader{p, len, cap} explictly
instead of makeslice returning the slice.
Reduces go binary size by ~0.2%.
Removes 92 (~3.5%) panicindex calls from go binary.
Change-Id: I29b7c3b5fe8b9dcec96e2c43730575071cfe8a94
Reviewed-on: https://go-review.googlesource.com/c/141822
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Previously, some of output from gdb matched with literal string, while
gdb v8.2 print the address of variable (e.g. map key and value) in
output.
This commit fix the regex in testing the output.
Fixes#27608
Change-Id: Ic3fe8280b9f93fda2799116804822616caa66beb
Reviewed-on: https://go-review.googlesource.com/135055
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
I omitted vendor directories and anything necessary for bootstrapping.
(Tested by bootstrapping with Go 1.4)
Updates #27864
Change-Id: I7d9b68d0372d3a34dee22966cca323513ece7e8a
Reviewed-on: https://go-review.googlesource.com/137856
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
We already aliased mSpanInUse to _MSpanInUse. The dual constants are
getting annoying, so fix all of these to use the mSpan* naming
convention.
This was done automatically with:
sed -i -re 's/_?MSpan(Dead|InUse|Manual|Free)/mSpan\1/g' *.go
plus deleting the existing definition of mSpanInUse.
Change-Id: I09979d9d491d06c10689cea625dc57faa9cc6767
Reviewed-on: https://go-review.googlesource.com/137875
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
See the added comment for the reasoning behind the workaround.
Fixes#26868.
Change-Id: Idede020ec88a49595dc233d9a1346b12691186f4
Reviewed-on: https://go-review.googlesource.com/128815
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This line of the inlining tuning experiment
https://go-review.googlesource.com/c/go/+/109918/1/src/cmd/compile/internal/gc/inl.go#347
was incorrectly rewritten in a later patch to use the call
cost, not the panic cost, and thus the inlining of panic
didn't occur when it should. I discovered this when I
realized that tests should have failed, but didn't.
Fix is to make the correct change, and also to modify the
tests that this causes to fail. One test now asserts the
new normal, the other calls "ppanic" instead which is
designed to behave like panic but not be inlined.
Change-Id: I423bb7f08bd66a70d999826dd9b87027abf34cdf
Reviewed-on: https://go-review.googlesource.com/116656
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
CL 93658 moved stack trace printing inside a systemstack call to
sidestep complexity in case the runtime is in a inconsistent state.
Unfortunately, debuggers generating backtraces for a Go panic
will be confused and come up with a technical correct but useless
stack. This CL moves just the crash performing - typically a SIGABRT
signal - outside the systemstack call to improve backtraces.
Unfortunately, the crash function now needs to be marked nosplit and
that triggers the no split stackoverflow check. To work around that,
split fatalpanic in two: fatalthrow for runtime.throw and fatalpanic for
runtime.gopanic. Only Go panics really needs crashes on the right stack
and there is enough stack for gopanic.
Example program:
package main
import "runtime/debug"
func main() {
debug.SetTraceback("crash")
crash()
}
func crash() {
panic("panic!")
}
Before:
(lldb) bt
* thread #1, name = 'simple', stop reason = signal SIGABRT
* frame #0: 0x000000000044ffe4 simple`runtime.raise at <autogenerated>:1
frame #1: 0x0000000000438cfb simple`runtime.dieFromSignal(sig=<unavailable>) at signal_unix.go:424
frame #2: 0x0000000000438ec9 simple`runtime.crash at signal_unix.go:525
frame #3: 0x00000000004268f5 simple`runtime.dopanic_m(gp=<unavailable>, pc=<unavailable>, sp=<unavailable>) at panic.go:758
frame #4: 0x000000000044bead simple`runtime.fatalpanic.func1 at panic.go:657
frame #5: 0x000000000044d066 simple`runtime.systemstack at <autogenerated>:1
frame #6: 0x000000000042a980 simple at proc.go:1094
frame #7: 0x0000000000438ec9 simple`runtime.crash at signal_unix.go:525
frame #8: 0x00000000004268f5 simple`runtime.dopanic_m(gp=<unavailable>, pc=<unavailable>, sp=<unavailable>) at panic.go:758
frame #9: 0x000000000044bead simple`runtime.fatalpanic.func1 at panic.go:657
frame #10: 0x000000000044d066 simple`runtime.systemstack at <autogenerated>:1
frame #11: 0x000000000042a980 simple at proc.go:1094
frame #12: 0x00000000004268f5 simple`runtime.dopanic_m(gp=<unavailable>, pc=<unavailable>, sp=<unavailable>) at panic.go:758
frame #13: 0x000000000044bead simple`runtime.fatalpanic.func1 at panic.go:657
frame #14: 0x000000000044d066 simple`runtime.systemstack at <autogenerated>:1
frame #15: 0x000000000042a980 simple at proc.go:1094
frame #16: 0x000000000044bead simple`runtime.fatalpanic.func1 at panic.go:657
frame #17: 0x000000000044d066 simple`runtime.systemstack at <autogenerated>:1
After:
(lldb) bt
* thread #7, stop reason = signal SIGABRT
* frame #0: 0x0000000000450024 simple`runtime.raise at <autogenerated>:1
frame #1: 0x0000000000438d1b simple`runtime.dieFromSignal(sig=<unavailable>) at signal_unix.go:424
frame #2: 0x0000000000438ee9 simple`runtime.crash at signal_unix.go:525
frame #3: 0x00000000004264e3 simple`runtime.fatalpanic(msgs=<unavailable>) at panic.go:664
frame #4: 0x0000000000425f1b simple`runtime.gopanic(e=<unavailable>) at panic.go:537
frame #5: 0x0000000000470c62 simple`main.crash at simple.go:11
frame #6: 0x0000000000470c00 simple`main.main at simple.go:6
frame #7: 0x0000000000427be7 simple`runtime.main at proc.go:198
frame #8: 0x000000000044ef91 simple`runtime.goexit at <autogenerated>:1
Updates #22716
Change-Id: Ib5fa35c13662c1dac2f1eac8b59c4a5824b98d92
Reviewed-on: https://go-review.googlesource.com/110065
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
This ensures that gdb tests run on Windows by ignoring any line ending.
Works with gdb 7.7, however with gdb 7.9 and 7.12 gets an error
error:
internal-error: buildsym_init: Assertion `free_pendings == NULL'
failed.
Updates #21380
Change-Id: I6a6e5b2a1b5efdca4dfce009fcb9c134c87497d6
Reviewed-on: https://go-review.googlesource.com/102419
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Previously find_goroutine determined whether a goroutine is
stopped by checking the sched.sp field. This heuristic doesn't
always hold but causes find_goroutine to return bogus pc/sp
info for running goroutines.
This change uses the atomicstatus bit to determine
the state which is more accurate.
R=go1.11
Change-Id: I537d432d9e0363257120a196ce2ba52da2970f59
Reviewed-on: https://go-review.googlesource.com/49691
Reviewed-by: Austin Clements <austin@google.com>
Minor.
Makes reading failing runtime test stacktraces easier (by having fewer
goroutines to read) on machines where these gdb tests wouldn't have
ever run anyway.
Change-Id: I3fab0667e017f20ef3bf96a8cc4cfcc614d25b5c
Reviewed-on: https://go-review.googlesource.com/81575
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Compiler and linker changes to support DWARF inlined instances,
see https://go.googlesource.com/proposal/+/HEAD/design/22080-dwarf-inlining.md
for design details.
This functionality is gated via the cmd/compile option -gendwarfinl=N,
where N={0,1,2}, where a value of 0 disables dwarf inline generation,
a value of 1 turns on dwarf generation without tracking of formal/local
vars from inlined routines, and a value of 2 enables inlines with
variable tracking.
Updates #22080
Change-Id: I69309b3b815d9fed04aebddc0b8d33d0dbbfad6e
Reviewed-on: https://go-review.googlesource.com/75550
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
TestGdbAutotmpTypes times out for unknown reasons on NetBSd. Skip the
gdb tests on NetBSD for now.
Updates #22893
Change-Id: Ibb05b7260eabb74d805d374b25a43770939fa5f2
Reviewed-on: https://go-review.googlesource.com/80136
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
It has always been problematic that there was no way to specify
tool flags that applied only to the build of certain packages;
it was only to specify flags for all packages being built.
The usual workaround was to install all dependencies of something,
then build just that one thing with different flags. Since the
dependencies appeared to be up-to-date, they were not rebuilt
with the different flags. The new content-based staleness
(up-to-date) checks see through this trick, because they detect
changes in flags. This forces us to address the underlying problem
of providing a way to specify per-package flags.
The solution is to allow -gcflags=pattern=flags, which means
that flags apply to packages matching pattern, in addition to the
usual -gcflags=flags, which is now redefined to apply only to
the packages named on the command line.
See #22527 for discussion and rationale.
Fixes#22527.
Change-Id: I6716bed69edc324767f707b5bbf3aaa90e8e7302
Reviewed-on: https://go-review.googlesource.com/76551
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Handle make(map[any]any) and make(map[any]any, hint) where
hint <= BUCKETSIZE special to allow for faster map initialization
and to improve binary size by using runtime calls with fewer arguments.
Given hint is smaller or equal to BUCKETSIZE in which case
overLoadFactor(hint, 0) is false and no buckets would be allocated by makemap:
* If hmap needs to be allocated on the stack then only hmap's hash0
field needs to be initialized and no call to makemap is needed.
* If hmap needs to be allocated on the heap then a new special
makehmap function will allocate hmap and intialize hmap's
hash0 field.
Reduces size of the godoc by ~36kb.
AMD64
name old time/op new time/op delta
NewEmptyMap 16.6ns ± 2% 5.5ns ± 2% -66.72% (p=0.000 n=10+10)
NewSmallMap 64.8ns ± 1% 56.5ns ± 1% -12.75% (p=0.000 n=9+10)
Updates #6853
Change-Id: I624e90da6775afaa061178e95db8aca674f44e9b
Reviewed-on: https://go-review.googlesource.com/61190
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The core dump reader would like a bunch of ideal int
constants to be available in dwarf.
Makes the go binary 0.9% bigger.
Update #14517
Change-Id: I00cdfc7f53bcdc56fccba576c1d33010f03bdd95
Reviewed-on: https://go-review.googlesource.com/69270
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Some (all?) versions of gdb on windows output "\r\n" as line ending
instead of "\n".
Fixes#22012
Change-Id: I798204fd9f616d6d2c9c28eb5227fadfc63c0d45
Reviewed-on: https://go-review.googlesource.com/65850
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Move it from the runtime package, as we will soon add more packages and
functions for it to check.
The test used the testEnv func, which cleaned certain environment
variables from a command, so it was moved to internal/testenv under a
more descriptive (and less ambiguous) name. Add a simple godoc to it
too.
For #21851.
Change-Id: I6f39c1f23b45377718355fafe66ffd87047d8ab6
Reviewed-on: https://go-review.googlesource.com/63550
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
This is a crude compiler pass to eliminate stores to auto variables
that are only ever written to.
Eliminates an unnecessary store to x from the following code:
func f() int {
var x := 1
return *(&x)
}
Fixes#19765.
Change-Id: If2c63a8ae67b8c590b6e0cc98a9610939a3eeffa
Reviewed-on: https://go-review.googlesource.com/38746
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
They were failing when run on 32bit RFS, with 32bit gdb.
(mips64 builder now has 64bit RFS, with gdb 7.9.)
Leaving TestGdbPythonCgo disabled, it behaves as described in #18784.
Fixes#18173
Change-Id: I3c438cd5850b7bfd118ac6396f40c1208bac8c2d
Reviewed-on: https://go-review.googlesource.com/45874
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The current implementation of "goroutine N cmd" assumes it can get
goroutine N's state from the goroutine's sched buffer. But this only
works if the goroutine is blocked. Extend find_goroutine so that, if
there is no saved scheduler state for a goorutine, it tries to find
the thread the goroutine is running on and use the thread's current
register state. We also extend find_goroutine to understand saved
syscall register state.
Fixes#13887.
Change-Id: I739008a8987471deaa4a9da918655e4042cf969b
Reviewed-on: https://go-review.googlesource.com/45031
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The experiment "clobberdead" clobbers all pointer fields that the
compiler thinks are dead, just before and after every safepoint.
Useful for debugging the generation of live pointer bitmaps.
Helped find the following issues:
Update #15936
Update #16026
Update #16095
Update #18860
Change-Id: Id1d12f86845e3d93bae903d968b1eac61fc461f9
Reviewed-on: https://go-review.googlesource.com/23924
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
It seems the problem is on gdb and the dynamic linker. Skip the
test for now until we figure out what's going on with the system.
Updates #18784.
Change-Id: Ic9320ffd463f6c231b2c4192652263b1cf7f4231
Reviewed-on: https://go-review.googlesource.com/36250
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Otherwise we don't emit any required ELF relocations when doing an
external link, because elfrelocsect skips unreachable symbols.
Fixes#18745.
Change-Id: Ia3583c41bb6c5ebb7579abd26ed8689370311cd6
Reviewed-on: https://go-review.googlesource.com/35590
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Autotmp filtering was too aggressive and excluded types
necessary to make debuggers work properly. Restore the
"late filter" in dwarf.go based on names to exclude autotmps,
and remove the "early filter" in pgen.go based on how the
name was introduced. However, the updated naming scheme
with a dot prefix is retained to prevent accidental clashes
with legal Go identifier names.
Includes test (grouped with runtime gdb tests),
verified to fail without the fix.
Updates #17644.
Fixes#17830.
Change-Id: I7ec3f7230083889660236e5f6bc77ba5fe434e93
Reviewed-on: https://go-review.googlesource.com/33233
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
I used the slowtests.go tool as described in
https://golang.org/cl/32684 on packages that stood out.
go test -short std drops from ~56 to ~52 seconds.
This isn't a huge win, but it was mostly an exercise.
Updates #17751
Change-Id: I9f3402e36a038d71e662d06ce2c1d52f6c4b674d
Reviewed-on: https://go-review.googlesource.com/32751
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Don't include package path when creating LSyms for auto and param
variables during Prog generation, and update the DWARF emit routine
accordingly (remove the code that chops off package path from names in
DWARF var location expressions). Implementation suggested by mdempsky@.
The intent of this change is to have saner location expressions in cases
where the variable corresponds to a structure field. For example, the
SSA compiler's "decompose" phase can take a slice value and break it
apart into three scalar variables corresponding to the fields (slice "X"
gets split into "X.len", "X.cap", "X.ptr"). In such cases we want the
name in the location expression to omit the package path but preserve
the original variable name (e.g. "X").
Fixes#16338
Change-Id: Ibc444e7f3454b70fc500a33f0397e669d127daa1
Reviewed-on: https://go-review.googlesource.com/31819
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
The canBackTrace variable is true for all of the architectures
Go supports and this is likely to remain the case as new
architectures are added.
Change-Id: I73900c018eb4b2e5c02fccd8d3e89853b2ba9d90
Reviewed-on: https://go-review.googlesource.com/22423
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Don't break on line number, instead break on the actual call.
This makes the test more robust to line numbering changes in the backend.
A CL (28950) changed the generated code line numbering slightly. A MOVW
$0, R0 instruction at the start of the function changed to line
10 (because several constant zero instructions got CSEd, and one gets
picked arbitrarily). That's too fragile for a test.
Change-Id: I5d6a8ef0603de7d727585004142780a527e70496
Reviewed-on: https://go-review.googlesource.com/29085
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This change makes sure that tests are run with the correct
version of the go tool. The correct version is the one that
we invoked with "go test", not the one that is first in our path.
Fixes#16577
Change-Id: If22c8f8c3ec9e7c35d094362873819f2fbb8559b
Reviewed-on: https://go-review.googlesource.com/28089
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Also adds missing copyright notice.
Updates #15603.
Change-Id: Icf4bb45ba5edec891491fe5f0039a8a25125d168
Reviewed-on: https://go-review.googlesource.com/23501
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
On some systems, gdb is set to: "startup-with-shell on". This
breaks runtime_test. This just make sure gdb does not start by
spawning a shell.
Fixes#15354
Change-Id: Ia040931c61dea22f4fdd79665ab9f84835ecaa70
Reviewed-on: https://go-review.googlesource.com/23142
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Also adds TestGdbBacktrace to the runtime package.
Dwarf modifications written by Bryan Chan (@bryanpkc) who is also
at IBM and covered by the same CLA.
Fixes#14628
Change-Id: I106a1f704c3745a31f29cdadb0032e3905829850
Reviewed-on: https://go-review.googlesource.com/20193
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This CL changes the source file information in the
standard library's .a files to say "$GOROOT/src/runtime/chan.go"
(with a literal "$GOROOT") instead of spelling out the actual directory.
The linker then substitutes the actual $GOROOT (or $GOROOT_FINAL)
as appropriate.
If people download a binary distribution to an alternate location,
following the instructions at https://golang.org/doc/install#install,
the code before this CL would end up with source paths pointing to
/usr/local/go no matter where the actual sources were.
Now the source paths for built binaries will point to the actual sources
(hopefully).
The source line information in distributed binaries is not affected:
those will still say /usr/local/go. But binaries people build themselves
(their own programs, not the go distribution programs) will be correct.
Fixing this path also fixes the lookup of the runtime-gdb.py file.
Fixes#5533.
Change-Id: I03729baae3fbd8cd636e016275ee5ad2606e4663
Reviewed-on: https://go-review.googlesource.com/18200
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
