This change replaces the crypto/ed25519/internal/edwards25519 package
with code from filippo.io/edwards25519, a significantly faster, safer,
well tested (over 1600 lines of new tests, 99% test coverage), and
better documented (600 lines of new comments) implementation.
Some highlights:
* an unsaturated 51-bit limb field implementation optimized for 64-bit
architectures and math/bits.Mul64 intrinsics
* more efficient variable time scalar multiplication using multi-width
non-adjacent form with a larger lookup table for fixed-base
* a safe math/big.Int-like API for the Scalar, Point, and field.Element
types with fully abstracted reduction invariants
* a test suite including a testing/quick fuzzer that explores edge case
values that would be impossible to hit randomly, and systematic tests
for arguments and receiver aliasing
* point decoding rules that strictly match the original logic of
crypto/ed25519/internal/edwards25519, to avoid consensus issues
* AssemblyPolicy-compliant assembly cores for arm64 and amd64, the
former under 20 lines, and the latter generated by a program based on
github.com/mmcloughlin/avo that can be reviewed line-by-line against
the generic implementation
Intel(R) Core(TM) i5-7400 CPU @ 3.00GHz
name old time/op new time/op delta
KeyGeneration-4 59.5µs ± 1% 26.1µs ± 1% -56.20% (p=0.000 n=10+10)
NewKeyFromSeed-4 59.3µs ± 1% 25.8µs ± 1% -56.48% (p=0.000 n=9+10)
Signing-4 60.4µs ± 1% 31.4µs ± 1% -48.05% (p=0.000 n=10+10)
Verification-4 169µs ± 1% 73µs ± 2% -56.55% (p=0.000 n=10+10)
Apple M1
name old time/op new time/op delta
KeyGeneration-8 35.1µs ± 0% 20.2µs ± 2% -42.46% (p=0.000 n=8+10)
NewKeyFromSeed-8 35.1µs ± 0% 20.0µs ± 1% -42.93% (p=0.000 n=8+9)
Signing-8 36.2µs ± 0% 25.6µs ± 1% -29.25% (p=0.000 n=8+9)
Verification-8 96.1µs ± 0% 57.6µs ± 1% -40.14% (p=0.000 n=10+10)
The code in this CL is a copy of the filippo.io/edwards25519 module at
version v1.0.0-beta.3.0.20210405211453-c6be47d67779 with only the
following functions removed as irrelevant to crypto/ed25519:
- (*Point).BytesMontgomery()
- (*Point).MultByCofactor()
- (*Scalar).Invert()
- (*Point).MultiScalarMult()
- (*Point).VarTimeMultiScalarMult()
This codebase took a long journey outside the standard library before
making its way back here. Its oldest parts started as a faster field
implementation rewrite by George Tankersley almost four years ago,
eventually submitted as CL 71950 but never merged. That code was then
merged into github.com/gtank/ristretto255, which also started as an
internal/edwards25519 fork. There it was worked on by me, George, and
Henry de Valence as a backend for our Go ristretto255 implementation.
Finally, I extracted the edwards25519 code into a reusable package as
filippo.io/edwards25519.
Now, we're ready for the standard library to become the source of truth
for this code again, while filippo.io/edwards25519 will become a
re-packaged and extended version for external use, since we don't want
to expose unsafe curve operations in x/crypto or the standard library.
Submitted under the Google CLA on behalf of:
- Henry de Valence
https://github.com/gtank/ristretto255/issues/34
- George Tankersley
https://golang.org/cl/71950https://github.com/gtank/ristretto255-private/issues/28
- Luke Champine
https://github.com/FiloSottile/edwards25519/pull/7
- Adrian Hamelink
https://github.com/FiloSottile/edwards25519/pull/12
Changes 32506b5 and 18c803c are trivial and don't require a CLA.
The full history of this code since diverging from internal/edwards25519
is available at https://github.com/FiloSottile/edwards25519, and
summarized below.
+ c6be47d - edwards25519: update TestScalarSetBytesWithClamping <Filippo Valsorda>
+ c882e8e - edwards25519: rewrite amd64 assembly with avo <Filippo Valsorda>
+ 8eb02eb - edwards25519: refactor feMulGeneric and feSquareGeneric <Filippo Valsorda>
+ 8afd860 - edwards25519: remove Go 1.12 compatibility hack <Filippo Valsorda>
+ 1765c13 - edwards25519: don't clobber BP in amd64 assembly <Filippo Valsorda>
+ b73a7c8 - edwards25519: fix ScalarMult when receiver is not the identity (FiloSottile/edwards25519#12) <Adrian Hamelink>
+ 32a46d7 - edwards25519: document why this can't implement X25519 <Filippo Valsorda>
+ c547797 - edwards25519: make SqrtRatio slightly more efficient <Filippo Valsorda>
+ 700f4f4 - edwards25519: panic if an uninitialized Point is used <Filippo Valsorda>
+ d791cf8 - edwards25519: use testing.AllocsPerRun for TestAllocations <Filippo Valsorda>
+ 8cc8037 - edwards25519: smooth a couple test coverage rough edges <Filippo Valsorda>
+ 9063a14 - edwards25519: test that operations cause zero heap allocations <Filippo Valsorda>
+ 6944ac7 - edwards25519: relax the limb schedule slightly <Filippo Valsorda>
+ 21ebdac - edwards25519: rewrite carryPropagate in arm64 assembly <Filippo Valsorda>
+ a260082 - edwards25519: merge carryPropagate[12] <Filippo Valsorda>
+ dbe1792 - edwards25519: add TestScalarSetBytesWithClamping <Filippo Valsorda>
+ c1fe95a - edwards25519: add MultByCofactor <Filippo Valsorda>
+ 132d95c - edwards25519: sprinkle on-curve checks around tests <Filippo Valsorda>
+ ffb3e31 - edwards25519: specify the behavior of Invert(0) and I.BytesMontgomery() <Filippo Valsorda>
+ 9e6a931 - edwards25519: add (*Scalar).MultiplyAdd <lukechampine>
+ 3b045f3 - edwards25519: outline (*Point).Bytes (FiloSottile/edwards25519#6) <Luke Champine>
+ ec6f8a6 - edwards25519: make (*Scalar).SetCanonicalBytes return the receiver <Filippo Valsorda>
+ 77d7b31 - edwards25519: add (*Point).BytesMontgomery <Filippo Valsorda>
+ 6e8d645 - edwards25519: implement (*Point).Bytes and (*Point).SetBytes <Filippo Valsorda>
+ 1c833da - edwards25519: clarify ScalarBaseMult docs <Filippo Valsorda>
+ 3a13cf1 - edwards25519: apply gc build tag <Filippo Valsorda>
+ 90c35a7 - edwards25519: hide FieldElement and (*Point).ExtendedCoords <Filippo Valsorda>
+ 498fb1e - edwards25519: replace FillBytes with Bytes, again <Filippo Valsorda>
+ 9c7303a - edwards25519: remove (*Point).Identity and (*Point).Generator <Filippo Valsorda>
+ 2e52ce2 - edwards25519: drop unused (*Scalar).Zero <Filippo Valsorda>
+ 7c14a36 - edwards25519: rename FromBytes to SetBytes <Filippo Valsorda>
+ e3d0e45 - edwards25519: ensure only test files import math/big <Filippo Valsorda>
+ daa2507 - edwards25519: minor doc and string touch-ups <Filippo Valsorda>
+ e8698cd - edwards25519: implement (*Scalar).FromBytesWithClamping <Filippo Valsorda>
+ f28d75a - edwards25519: change constructors <Filippo Valsorda>
+ 36d8598 - edwards25519: test the invariant that Scalars are always reduced <Filippo Valsorda>
+ feed48c - edwards25519: cleanup the FieldElement API <Filippo Valsorda>
+ f6ee187 - edwards25519: make Point opaque <Filippo Valsorda>
+ 176388b - edwards25519: cleanup Scalar API to match ristretto255 <Filippo Valsorda>
+ c5c2e9e - edwards25519: rename ProjP3 to Point and unexport other point types <Filippo Valsorda>
+ 8542076 - edwards25519: add Scalar aliasing test <Filippo Valsorda>
+ 1a86a9c - edwards25519: make Scalar opaque <Filippo Valsorda>
+ 07a7683 - edwards25519: hide some more exposed symbols <Filippo Valsorda>
+ d3569cb - all: flatten the package and make FieldElement opaque <Filippo Valsorda>
+ 6f5f582 - all: expose edwards25519, base, and scalar packages <Filippo Valsorda>
+ 7ab4a68 - all: ensure compatibility with older Go versions <Filippo Valsorda>
+ e9b8baa - internal/radix51: implement (*FieldElement).Mul32 <Filippo Valsorda>
+ eac4de5 - internal/radix51: restructure according to golang.org/wiki/TargetSpecific <Filippo Valsorda>
+ 32506b5 - internal/radix51: fix !amd64 build (lightReduce -> carryPropagate) (gtank/ristretto255#29) <Sunny Aggarwal>
+ d64d989 - internal/scalar: fix FromUniformBytes <Filippo Valsorda>
+ 044bb44 - internal/scalar: address review comments <Filippo Valsorda>
+ 7dba54f - all: apply suggestions from code review <Filippo Valsorda>
+ 94bd1d9 - ristretto255: expose scalar multiplication APIs <Filippo Valsorda>
+ 5bd5476 - internal/edwards25519: fix shadowing of B in TestAddSubNegOnBasePoint <Filippo Valsorda>
+ 66bf647 - internal/scalar: replace FromBytes/IsCanonical with FromUniformBytes/FromCanonicalBytes <Filippo Valsorda>
+ 024f3f7 - internal/edwards25519,internal/scalar: apply some Go style touches <Filippo Valsorda>
+ 5e0c5c6 - internal/scalar: add scalar inversion <Henry de Valence>
+ 74fd625 - internal/ed25519: rearrange VartimeDoubleBaseMul args <Henry de Valence>
+ 81ae7ea - internal/ed25519: add benchmarks for scalar mul <Henry de Valence>
+ 9f1f939 - internal/ed25519: add variable-time multiscalar mul <Henry de Valence>
+ 7a96974 - internal/ed25519: add vartime double-base scmul <Henry de Valence>
+ 2bc256c - internal/ed25519: add precomputed NAF table for basepoint <Henry de Valence>
+ a0f0b96 - internal/ed25519: lower quickcheck size for point ops <Henry de Valence>
+ 2f385a1 - internal/ed25519: implement MultiscalarMul <Henry de Valence>
+ 8ae211b - internal/ed25519: implement BasepointMul <Henry de Valence>
+ 7b4858d - internal/ed25519: extract common test variables <Henry de Valence>
+ 16e7c48 - internal/ed25519: add a basepoint multiple table. <Henry de Valence>
+ 988e521 - internal/ed25519: add constant-time variable-base scmul. <Henry de Valence>
+ b695f6b - internal/ed25519: move basepoint constant & correct it <Henry de Valence>
+ ddd014e - internal/scalar: fix high bit check <Henry de Valence>
+ c88ea89 - internal/scalar: make casts clearer <Henry de Valence>
+ b75f989 - internal/scalar: add invariant checks on Scalar digits <Henry de Valence>
+ 36216ca - internal/scalar: use one scMulAdd for Sub <Henry de Valence>
+ 8bf40f3 - internal/scalar: fix constant-time signed radix 16 implementation <Henry de Valence>
+ e6d9ef6 - Update internal/radix51/fe_test.go <Filippo Valsorda>
+ 3aa63de - Update internal/radix51/fe_test.go <Filippo Valsorda>
+ 3e66ff0 - Update internal/radix51/fe_test.go <Filippo Valsorda>
+ 94e6c15 - internal/ed25519: add TODO note and doc ref <Henry de Valence>
+ 3647548 - internal/ed25519: rename twoD to D2 <Henry de Valence>
+ 1cf853c - internal/ed25519: add lookup tables for scalar mul. <Henry de Valence>
+ 3af304a - internal/radix51: add a conditional swap <Henry de Valence>
+ 4673217 - ristretto255: use multi-model arithmetic <Henry de Valence>
+ cca757a - internal/ed25519: remove single-model code <Henry de Valence>
+ d26e77b - internal/ed25519: add addition for Edwards points <Henry de Valence>
+ e0fbb35 - internal/ed25519: use twoD <Henry de Valence>
+ fd9b37b - internal/ed25519: add tests for multi-model point types. <Henry de Valence>
+ dacabb0 - internal/ed25519: add multi-model point types. <Henry de Valence>
+ dddc72e - internal/scalar: add constant-time signed radix 16 <Henry de Valence>
+ 92cdb35 - internal/scalar: add non-adjacent form <Henry de Valence>
+ d147963 - internal/scalar: don't zero memory that is about to be copied over <George Tankersley>
+ 8da186c - internal/scalar: add scalar field implementation <George Tankersley>
+ f38e583 - internal/radix51: add a "weird" testing/quick generation strategy <Filippo Valsorda>
+ 6454f61 - Move comment inside function <Henry de Valence>
+ 1983365 - implement Add, Sub, Neg for ed25519 and ristretto255 points. <Henry de Valence>
+ 9f25562 - internal/group: rename to internal/edwards25519 <Filippo Valsorda>
+ 48e66d3 - internal/group: restore ScalarMult code <Filippo Valsorda>
+ 0078d66 - internal/radix51: rename lightReduce to carryPropagate and touch up docs <Filippo Valsorda>
+ 05f4107 - internal/radix51: add benchmarks <Filippo Valsorda>
+ fd36334 - internal/radix51: test that operations don't exceed bounds <Filippo Valsorda>
+ 703421d - internal/radix51: make Generate produce random light-reduced elements <Filippo Valsorda>
+ f8d8297 - internal/radix51: simplify lightReduce <Filippo Valsorda>
+ 413120f - internal/radix51: minor tests cleanup <Filippo Valsorda>
+ abc8c5a - internal/radix51: make reduction an invariant and unexport Reduce <Filippo Valsorda>
+ 4fd198d - internal/radix51: actually apply go:noescape <Filippo Valsorda>
+ 18c803c - all: fix typos <Dimitris Apostolou>
+ bbfe059 - internal/radix51: test field encoding roundtrip with fixed vectors <George Tankersley>
+ c428b18 - internal/radix51: rename AppendBytes to Bytes <Filippo Valsorda>
+ c59bc1a - internal/radix51: rewrite FromBytes and AppendBytes with encoding/binary <Filippo Valsorda>
+ 57c0cd5 - internal/radix51: add docs and some light readability refactors <Filippo Valsorda>
+ cb1b734 - internal/radix51: remove unused (and a bit broken) SetInt <Filippo Valsorda>
+ beb8abd - internal/radix51: refactor ToBig and FromBig <Filippo Valsorda>
+ 87c0a53 - internal/radix51: replace ToBytes with AppendBytes <Filippo Valsorda>
+ b7e1e45 - internal/radix51: fix aliasing bug in CondNeg (gtank/ristretto255#21) <George Tankersley>
+ ed3748d - internal/radix51: actually, uhm, check the result of TestAliasing <Filippo Valsorda>
+ ec0e293 - radix51: change API of FromBytes and ToBytes to use slices <George Tankersley>
+ 29f6815 - internal/radix51: test all combinations of argument and receiver aliasing <Filippo Valsorda>
+ cd53d90 - internal/radix51: add property-based tests that multiplication distributes over addition <Henry de Valence>
+ c3bc45f - radix51: use go1.12 intrinsics for 128-bit multiplications <George Tankersley>
+ 7e7043e - internal/radix51: define a mask64Bits constant <Filippo Valsorda>
+ 4fdd06d - internal/group: set Z to 1, not 0 in FromAffine <Filippo Valsorda>
+ ffa7be7 - internal/group: fix typo <Filippo Valsorda>
+ 1f452ac - internal/group: derive twoD from D <Filippo Valsorda>
+ 2424c78 - internal/radix51: add MinusOne <Filippo Valsorda>
+ 76978fc - internal/group: make conversion APIs caller-allocated <Filippo Valsorda>
+ d17d202 - internal/group: rewrite DoubleZ1 because stack is cheaper than mental state <Filippo Valsorda>
+ 72b97c1 - internal: make all APIs chainable <Filippo Valsorda>
+ 993d979 - internal/radix51: make all APIs not consider the receiver an input <Filippo Valsorda>
+ b2a1d7d - all: refactor field API to be methods based <Filippo Valsorda>
+ cdf9b90 - internal/radix51: add constant time field operations <Filippo Valsorda>
+ e490a48 - internal/radix51: remove FeEqual <Filippo Valsorda>
+ 2de114c - internal/radix51: remove FeCSwap <Filippo Valsorda>
+ 08b80c1 - make things more generally presentable <George Tankersley>
+ 2178536 - Cache the field representation of d <George Tankersley>
+ 4135059 - Remove 32-bit code and update license. <George Tankersley>
+ 5d95cb3 - Use Bits() for FeToBig. <George Tankersley>
+ 146e33c - Implement ScalarMult using Montgomery pattern and dedicated extended-coordinates doubling. This will be slow. <George Tankersley>
+ 12a673a - use faster FeFromBig & a horrible assortment of other random changes <George Tankersley>
+ 901f40c - group logic WIP <George Tankersley>
+ a9c89cd - add equality for field elements <George Tankersley>
+ 214873b - Add radix51 FieldElement implementation <George Tankersley>
+ 8fd5cae - Implement an elliptic.Curve for ed25519 <George Tankersley>
Change-Id: Ifbcdd13e8b6304f9906c0ef2b73f1fdc493a7dfa
Co-authored-by: George Tankersley <george.tankersley@gmail.com>
Co-authored-by: Henry de Valence <hdevalence@hdevalence.ca>
Reviewed-on: https://go-review.googlesource.com/c/go/+/276272
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Filippo Valsorda <filippo@golang.org>
Trust: Katie Hockman <katie@golang.org>
Reviewed-by: Katie Hockman <katie@golang.org>
This is a port of CL 317329 to go/types.
Change-Id: I1ba65284c91044f0ceed536da4149ef25e1f9502
Reviewed-on: https://go-review.googlesource.com/c/go/+/317291
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
Change-Id: I88c5e1f620d0f3546ac9ac7b6a4b881772a38449
Reviewed-on: https://go-review.googlesource.com/c/go/+/317329
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
The inlsubst already does the same thing for OLABEL, so we must do the
same thing for OGOTO. Otherwise, new inlined OGOTO node will be
associated with non-existed label.
Fixes#45947
Change-Id: I40eef095f57fd3438c38a0b5d9751d5d7ebf759e
Reviewed-on: https://go-review.googlesource.com/c/go/+/316931
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>
For #36460
Change-Id: I725ef5445b2bac7af827fb38373e8cd6dbad2d09
Reviewed-on: https://go-review.googlesource.com/c/go/+/316249
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Reviewed-by: Michael Matloob <matloob@golang.org>
They empirically do not seem to support deleting the current working
directory.
Updates #34499
Change-Id: I705cdf8b545fbb837d5b75d2904a7c2a89276fa5
Reviewed-on: https://go-review.googlesource.com/c/go/+/317249
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Robert Findley <rfindley@google.com>
If no source argument is provided, test testdata/manual.go2
instead.
Remove testdata/check/tmp/go2 in favor of testdata/manual.go2.
These changes affect testing only.
Change-Id: I49aba4d8fc4cc5964911e38c55b4c5d013710aeb
Reviewed-on: https://go-review.googlesource.com/c/go/+/315769
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
Revive CL 310149
Change-Id: Ib4714ea5b2ade32c0f66edff841a79d8212bd79a
Reviewed-on: https://go-review.googlesource.com/c/go/+/313009
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Trust: Michael Pratt <mpratt@google.com>
Trust: Michael Knyszek <mknyszek@google.com>
The Go 1.17 freeze has begun. This is a time to update all
golang.org/x/... module versions that contribute packages to the std
and cmd modules in the standard library to latest master versions.
updatestd --branch master --goroot=$HOME/development/goroot
> go version
go version devel go1.17-4c9791299d Wed May 5 09:00:06 2021 +0000 linux/amd64
> go env GOROOT
/home/rakoczy/development/goroot
> go version -m /home/rakoczy/go/bin/bundle
/home/rakoczy/go/bin/bundle: devel +c584f42dcf Tue Feb 23 18:39:53 2021 +0000
path golang.org/x/tools/cmd/bundle
mod golang.org/x/tools v0.1.0 h1:po9/4sTYwZU9lPhi1tOrb4hCv3qrhiQ77LZfGa2OjwY=
dep golang.org/x/mod v0.3.0 h1:RM4zey1++hCTbCVQfnWeKs9/IEsaBLA8vTkd0WVtmH4=
dep golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4 h1:myAQVi0cGEoqQVR5POX+8RR2mrocKqNN1hmeMqhX27k=
dep golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
skipping github.com/chzyer/logex (out of scope, it's not a golang.org/x dependency)
skipping github.com/chzyer/readline (out of scope, it's not a golang.org/x dependency)
skipping github.com/chzyer/test (out of scope, it's not a golang.org/x dependency)
skipping github.com/google/pprof (out of scope, it's not a golang.org/x dependency)
skipping github.com/ianlancetaylor/demangle (out of scope, it's not a golang.org/x dependency)
skipping github.com/yuin/goldmark (out of scope, it's not a golang.org/x dependency)
skipping rsc.io/pdf (out of scope, it's not a golang.org/x dependency)
updating module cmd in /home/rakoczy/development/goroot/src/cmd
> go mod edit -go=1.17
> go get -d golang.org/x/arch@cbf565b21d1e6f86b3114f28f516032b201c97fa golang.org/x/crypto@e9a32991a82ef02a1e74f495dcc0785239782bfe golang.org/x/mod@67f1c1edc27ada9b0cffe84ccdd4db2d4ff56edf golang.org/x/net@0287a6fb4125c2b83c66560a2677a4ee69a13903 golang.org/x/sync@036812b2e83c0ddf193dd5a34e034151da389d09 golang.org/x/sys@0981d6026fa6241c75c6949829b5bd7a2574ad55 golang.org/x/term@a79de5458b56c188f4fc267a58014ac25fec956a golang.org/x/text@5c7c50ebbd4f5b0d53b9b2fcdbeb92ffb732a06e golang.org/x/tools@7cab0ef2e9a592f6a73e7a1969ba89d38515e143 golang.org/x/xerrors@5ec99f83aff198f5fbd629d6c8d8eb38a04218ca
go: downloading golang.org/x/mod v0.4.3-0.20210504181020-67f1c1edc27a
go: downloading golang.org/x/crypto v0.0.0-20210503195802-e9a32991a82e
go: downloading golang.org/x/net v0.0.0-20210505024714-0287a6fb4125
go: downloading golang.org/x/sys v0.0.0-20210503173754-0981d6026fa6
go: downloading golang.org/x/text v0.3.7-0.20210503195748-5c7c50ebbd4f
go: downloading golang.org/x/tools v0.1.1-0.20210505014545-7cab0ef2e9a5
go get: upgraded golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4 => v0.0.0-20210505024714-0287a6fb4125
go get: upgraded golang.org/x/sys v0.0.0-20210423082822-04245dca01da => v0.0.0-20210503173754-0981d6026fa6
go get: upgraded golang.org/x/text v0.3.3 => v0.3.7-0.20210503195748-5c7c50ebbd4f
go get: upgraded golang.org/x/tools v0.1.1-0.20210503200558-19b1717ea5eb => v0.1.1-0.20210505014545-7cab0ef2e9a5
> go mod tidy
> go mod vendor
updating module std in /home/rakoczy/development/goroot/src
> go mod edit -go=1.17
> go get -d golang.org/x/crypto@e9a32991a82ef02a1e74f495dcc0785239782bfe golang.org/x/net@0287a6fb4125c2b83c66560a2677a4ee69a13903 golang.org/x/sys@0981d6026fa6241c75c6949829b5bd7a2574ad55 golang.org/x/term@a79de5458b56c188f4fc267a58014ac25fec956a golang.org/x/text@5c7c50ebbd4f5b0d53b9b2fcdbeb92ffb732a06e golang.org/x/tools@7cab0ef2e9a592f6a73e7a1969ba89d38515e143
go get: upgraded golang.org/x/net v0.0.0-20210503060351-7fd8e65b6420 => v0.0.0-20210505024714-0287a6fb4125
go get: upgraded golang.org/x/sys v0.0.0-20210423082822-04245dca01da => v0.0.0-20210503173754-0981d6026fa6
go get: upgraded golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1 => v0.0.0-20210503060354-a79de5458b56
go get: upgraded golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e => v0.1.1-0.20210505014545-7cab0ef2e9a5
> go mod tidy
> go mod vendor
updating bundles in /home/rakoczy/development/goroot/src
> go generate -run=bundle std cmd
For #36905
Change-Id: Ie145bba93125f0b4212df94216e05ec08c4fe534
Reviewed-on: https://go-review.googlesource.com/c/go/+/315831
Trust: Alexander Rakoczy <alex@golang.org>
Run-TryBot: Alexander Rakoczy <alex@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
The setg call a few lines earlier has already performed the same iscgo check
and called save_g if necessary.
Change-Id: I6e7c44cef4e0397d6001a3d5b7e334cdfbc3ce22
Reviewed-on: https://go-review.googlesource.com/c/go/+/316929
Trust: Joel Sing <joel@sing.id.au>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Instantiation support for imports. This is experimental
but it also doesn't affect Go 1.17 as this code is not
executed unless we enable generics (in the parser).
Change-Id: If2da09ac3a557ec6a180707a53f75f3ce354f3e9
Reviewed-on: https://go-review.googlesource.com/c/go/+/314773
Trust: Robert Griesemer <gri@golang.org>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>
Add some rudimentary debug trace output for -N location list
generation if "-d=ssa/locationlists" is set.
Updates #45948.
Change-Id: If1a95730538a6e7def7ebe1ece1a71da8e5f0975
Reviewed-on: https://go-review.googlesource.com/c/go/+/317089
Trust: Than McIntosh <thanm@google.com>
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
The code that created DWARF debug var locations for input parameters
in the non-optimized case for regabi was not doing the right thing for
degenerate functions with infinite loops. Detect these cases and don't
try to emit the normal location data.
Fixes#45948.
Change-Id: I2717fc4bac2e03d5d850a6ec8a09ed05fed0c896
Reviewed-on: https://go-review.googlesource.com/c/go/+/316752
Trust: Than McIntosh <thanm@google.com>
Run-TryBot: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
If the go command is executed on Linux in a deleted directory,
it fails. This behavior is reasonable for commands which depend on
the CWD, but it's unexpected for commands like `go version`.
This change delays initialization of a global CWD variable.
Fixed#34499
Change-Id: I7302fb84a3b7f5f149a123d277abd5b9b5bc95b2
Reviewed-on: https://go-review.googlesource.com/c/go/+/268261
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Trust: Bryan C. Mills <bcmills@google.com>
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
I missed the 'go mod tidy' step in CL 316751 because I forgot to run
the cmd/internal/moddeps test in long mode. 😞
Updates #45932
Change-Id: Ic3f9b303ad5798ecd8cb044d4b8c766aa820bf69
Reviewed-on: https://go-review.googlesource.com/c/go/+/317129
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Fixes#45447
Change-Id: I1b1a0a844ee4345ced1a007bbe53db035183175f
Reviewed-on: https://go-review.googlesource.com/c/go/+/311529
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Updates #44933.
Change-Id: I0c4c2a54f67b47771f4fa59f11c47fa7b0dde799
Reviewed-on: https://go-review.googlesource.com/c/go/+/317029
Trust: Matthew Dempsky <mdempsky@google.com>
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
In a lazy module, it is important that tidyRoots does not add any new
roots because the dependencies of non-roots are pruned out.
In an eager module, that property is not important (and does not hold
in general) because no dependencies are ever pruned out.
Fixes#45952
Change-Id: I5c95b5696b7112b9219e38af04e0dece7fb6e202
Reviewed-on: https://go-review.googlesource.com/c/go/+/316754
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
For #45952
Change-Id: I90e895e2fd10bccd947f9ee5133f942fea218a07
Reviewed-on: https://go-review.googlesource.com/c/go/+/316753
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Currently if a signal lands on a non-Go thread that's handled by the Go
handler, Go will emit a message. However, unlike everywhere else in the
runtime, Go will not abort the process after, and the signal handler
will try to continue executing.
This leads to cascading failures and possibly even memory corruption.
For #45638.
Change-Id: I546f4e82f339d555bed295528d819ac883b92bc6
Reviewed-on: https://go-review.googlesource.com/c/go/+/316809
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
For #44513.
For #23011.
Change-Id: Ic092e38da3601a43d7e2110f500db4a6a6f845f5
Reviewed-on: https://go-review.googlesource.com/c/go/+/316889
Trust: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Alexander Rakoczy <alex@golang.org>
Reviewed-by: Carlos Amedee <carlos@golang.org>
When the expand_calls phase in the SSA backend lowers prolog OpArg
values into OpArgIntReg/OpArgFloatReg values, we don't always record
the assocation between the new lowered value and the parameter name.
This patch handles the simple case where a given parameter fits into
exactly one register; in this scenario it makes sense to manufacture a
new pseudo-slot for the value that points to the param, and install
the slot/value mapping in the NamedValues table for the function. More
work will be needed to deal with params that span multiple registers;
that will need to be addressed in a subsequent patch.
This change improves the parameter error rate "optargorder" benchmark
by about 7-8% (when run on the optargorder binary).
Updates #45945.
Change-Id: Ic9adbe20b6f91145d49651348818f0f5cba92b18
Reviewed-on: https://go-review.googlesource.com/c/go/+/316890
Trust: Than McIntosh <thanm@google.com>
Run-TryBot: Than McIntosh <thanm@google.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
This test deletes the running executable file, which is not safe
on Plan 9. The test was working by accident prior to commit 02ab8d1,
which must have changed the page reference ordering just enough to
cause a new demand page-in after deletion of the file.
Fixes#45941
Change-Id: Ic13d8032c21cee603e3afc3c5c4da6093fc37bf4
Reviewed-on: https://go-review.googlesource.com/c/go/+/316829
Reviewed-by: David du Colombier <0intro@gmail.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Trust: David du Colombier <0intro@gmail.com>
Run-TryBot: David du Colombier <0intro@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
All build environment validation sets Error except for the
GOEXPERIMENT parser, which panics. Change it to also set Error so that
a bad GOEXPERIMENT doesn't cause everything that imports
internal/buildcfg to panic on init.
Change-Id: Ie9a506ef0978ecb410f2dcd784638f2167354175
Reviewed-on: https://go-review.googlesource.com/c/go/+/310970
Trust: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
TestSignalTrace can take a bit longer to run on some
ppc64{,le} machines. I was only able to reproduce the
timeout reliably on a POWER8/ppc64le ubuntu 16.04 host.
Bump the timeout to 5 seconds. This should be more than
sufficient for a test which occasionally takes a bit
longer to run on these builders.
Fixes#45773
Change-Id: I4177bb986561f714aabfa5b0ca44b1c90b1cd94f
Reviewed-on: https://go-review.googlesource.com/c/go/+/315049
Run-TryBot: Paul Murphy <murp@ibm.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Trust: Lynn Boger <laboger@linux.vnet.ibm.com>
If we're testing through dist, we're testing the implementation of Go,
so we're interested in any package failing with potential runtime
issues. In these cases, we'd like to have as much relevant detail as
possible, but currently runtime stack frames and goroutines are
suppressed due to the default GOTRACEBACK setting.
So, try to set GOTRACEBACK to system if it's unset. Check if it's unset
first so we don't override the user asking for a lower or higher level.
This change was brought up in the context of #45916, since there's an
apparent deadlock (or something!) in the runtime that appears when
running other code, but it's difficult to see exactly where it's
blocked. However, this change is very generally useful.
This change also runs scripted tests with GOTRACEBACK=system, upgrading
from GOTRACEBACK=all. Often, script tests can trigger failures deep in
the runtime in interesting ways because they start many individual Go
processes, so being able to identify points of interest in the runtime
is quite useful.
For #45916.
Change-Id: I3d50658d0d0090fb4c9182b87200d266c7f8f915
Reviewed-on: https://go-review.googlesource.com/c/go/+/316469
Trust: Michael Knyszek <mknyszek@google.com>
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Since x/tools is now lazy, this removes a significant fraction of
otherwise-irrelevant dependencies from the go.sum file.
The remaining extraneous go.sum lines come from the dependency on
github.com/google/pprof. Since that module is outside of the Go
project proper, I do not plan to submit a PR to make it lazy until
after the Go 1.17 release.
For #36460
Updates #36905
Change-Id: I214492cf931fca797817124ecdcbccd4ebb7505b
Reviewed-on: https://go-review.googlesource.com/c/go/+/316452
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Alexander Rakoczy <alex@golang.org>
The outdated comment in modfile.go was missed in CL 315409.
Upon a closer look at the test case in mod_go_version_vendor.txt, it
is almost completely redundant with the new test in
mod_vendor_goversion.txt. Make it completely redundant and remove it.
Updates #36876
Change-Id: Ibcd1f6b426460aaafbd6dc0be93078547904572b
Reviewed-on: https://go-review.googlesource.com/c/go/+/316209
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Because x/crypto is now lazy, this removes the remaining checksums for
older-than-selected dependencies from src/go.sum.
It also removes a significant fraction of the irrelevant checksums
from src/cmd/go.sum.
For #36460
Updates #36905
Change-Id: I33af5fc638aa1d1c66df3a1d86542912e95a7f50
Reviewed-on: https://go-review.googlesource.com/c/go/+/316451
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Alexander Rakoczy <alex@golang.org>
Because x/text is now lazy, the go.sum file no longer needs a checksum
for the go.mod file for the outdated x/tools required by x/text.
For #36460
Updates #36905
Change-Id: Id7395e61909af3889c1615dc33139e5bb45504c5
Reviewed-on: https://go-review.googlesource.com/c/go/+/316490
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Alexander Rakoczy <alex@golang.org>
Even though x/mod is now lazy, this has no immediate effect on the
size of cmd/go.sum: all of the existing dependencies are still pulled
in via the dependency on x/tools, which is itself not yet lazy (that's
CL 315570).
For #36460
Updates #36905
Change-Id: I7bce5fe2596a2d71e4df08f5d5f4cb8dcdb8512c
Reviewed-on: https://go-review.googlesource.com/c/go/+/316489
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Alexander Rakoczy <alex@golang.org>
We were already setting GIT_SSH_COMMAND (if unset) to explicitly
include 'ControlMaster=no' in order to disable connection pooling.
Now we also set 'BatchMode=yes' to suppress password prompts for
password-protected keys.
While we're here, we also set GCM_INTERACTIVE=never to suppress
similar prompts from the Git Credential Manager for Windows.
Fixes#44904
Change-Id: Iebb050079ff7dd54d5b944c459ae212e9e6f2579
Reviewed-on: https://go-review.googlesource.com/c/go/+/300157
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Lots of constant SSA values we put in the entry block so that
CSE can easily combine them. With -N, however, we don't run CSE, so
putting values in the entry block only serves to extend their lifetime
for no benefit.
Fixes#45897. The number of live SSA values per block goes from >5K to 22.
Memory use goes from ~3GB to ~400MB.
Change-Id: I620b423611790a900e0d4cd270eac5dbdddf2a2b
Reviewed-on: https://go-review.googlesource.com/c/go/+/316369
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
This is part of getting debugging into good shape
with the register ABI. (This may generate a backport
for 1.16, there was some regression there as well.)
This is not necessarily fully-baked yet; my goal is to
make it work "well enough" for actual debugging, then
revisit the metrics, which are currently ignorant
of registers used for passing parameters (currently,
rejects them as a valid option).
Updates #40724.
Change-Id: Ib649adf39f947b7b54895c5bf181cf48ca4d38a0
Reviewed-on: https://go-review.googlesource.com/c/go/+/311689
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Follow CL 23967 and CL 24021 which did the same on linux and freebsd,
respectively.
Updates #13987
Updates #16028
Change-Id: I95b13d8ddde4cea1ef4fb7d655f1ad1a219d13aa
Reviewed-on: https://go-review.googlesource.com/c/go/+/315281
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
QuotedPrefix is similar to Unquote, but returns the quoted string verbatim
and ignores any data after the quoted string.
Fixes#45033
Change-Id: I9f69fe9e3e45cbe9e63581cf1b457facb625045d
Reviewed-on: https://go-review.googlesource.com/c/go/+/314775
Trust: Joe Tsai <joetsai@digital-static.net>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
The functions SwapPointer and CompareAndSwapPointer can be used to
interact with unsafe.Pointer, however generally it is prefered to work
with Value, due to its safer interface. As such, they have been added
along with glue logic to maintain invariants Value guarantees.
To meet these guarantees, the current implementation duplicates much of
the Store function. Some of this is due to inexperience with concurrency
and desire for correctness, but the lack of generic programming
functionality does not help.
Fixes#39351
Change-Id: I1aa394b1e70944736ac1e19de49fe861e1e46fba
Reviewed-on: https://go-review.googlesource.com/c/go/+/241678
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
This adds a new lock protecting "tmpl".
This is a copy of https://golang.org/cl/257817 by Andreas Fleig,
updated for current tip, and updated to start running the
html/template TestEscapeRace test.
Thanks to @bep for providing the test case.
Fixes#39807
Change-Id: Ic8874484290283a49116812eeaffb8608346dc70
Reviewed-on: https://go-review.googlesource.com/c/go/+/316669
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Following CL 313230, this is for internal/syscall/unix package.
Updates #45702.
Change-Id: Ie6d8c1923dfeae56896212393c5c2a6e257648d2
Reviewed-on: https://go-review.googlesource.com/c/go/+/316649
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Since we have int8 to int64 min max and uint8 to uint64 max constants,
we should probably have some for the word size types too. This change
also adds tests to validate the correctness of all integer limit
values.
Fixes#28538
Change-Id: Idd25782e98d16c2abedf39959b7b66e9c4c0c98b
Reviewed-on: https://go-review.googlesource.com/c/go/+/247058
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Robert Griesemer <gri@golang.org>
These new methods provide support for cases where performance is a
primary concern. For example, copying files from an existing zip to a
new zip without incurring the decompression and compression overhead.
Using an optimized, external compression method and writing the output
to a zip archive. And compressing file contents in parallel and then
sequentially writing the compressed bytes to a zip archive.
TestWriterCopy is copied verbatim from https://github.com/rsc/zipmergeFixes#34974
Change-Id: Iade5bc245ba34cdbb86364bf59f79f38bb9e2eb6
Reviewed-on: https://go-review.googlesource.com/c/go/+/312310
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Carlos Amedee <carlos@golang.org>
At this time, the golang.org/s/release process arranges such that the
api/go1.n.txt file is created when a Go 1.N Beta 1 release is being cut.
The API check is currently configured so that tests don't fail visibly
even if api/go1.n.txt becomes a subset of the actual API additions in
the upcoming Go 1.N release as long as 'go version' has "devel" in it.
The first time that 'go version' output drops the "devel" substring
during testing is after the release-branch.go1.N branch is created
as part of the process to cut a Go 1.N Release Candidate 1 release.
The month or so between Beta 1 and RC 1 is well into the freeze and
deliberate API changes are rare and very intentional. There seems to
be agreement that it's healthy to make the API check stricter during
that time period. Doing so will ensure that api/go1.n.txt cannot get
stale after creation without anyone noticing, and may catch CLs that
don't have the intended diff on the API.
This CL changes behavior to be simple and clear: from the moment
an api/go1.n.txt file corresponding to the current Go version in
development is added to the tree, silent API additions stop being
permitted.
This CL also moves the magical "override the value of -allow_new flag
if runtime.Version() contains 'devel' string" behavior from cmd/api
command to the run.go script that calls it, making the CLI of cmd/api
itself less surprising.
Fixes#43956.
Change-Id: I89468207573f7ccdbc9f12625dcdd3ef2bcf8f10
Reviewed-on: https://go-review.googlesource.com/c/go/+/315350
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
Trust: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Alexander Rakoczy <alex@golang.org>
As a side effect, this also upgrades x/sys to the version currently
required by the latest x/net.
Because x/net is now lazy, it no longer requires checksums for
older-than-selected versions of x/sys, x/term, and x/text.
For #36460
Updates #36905
Change-Id: I242815e202aa7d482fc3983a6717bece10ea8111
Reviewed-on: https://go-review.googlesource.com/c/go/+/316251
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
