-W and -w turn on printing of Nodes for both order and walk.
I have found their output mildly incomprehensible for years.
Improve it, at long last.
Change-Id: Ia05d77e59aa741c2dfc9fcca07f45019420b655e
Reviewed-on: https://go-review.googlesource.com/114520
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
When using gccgo/GoLLVM, there is no package file for a standard
library package. Since it is impossible for the go tool to rebuild the
package, and since the package file exists only in the form of a .gox
file, this seems like the best choice. Unfortunately it was confusing
vet, which wanted to see a real file. This caused vet to report errors
about missing package files for standard library packages. The
gccgoimporter knows how to correctly handle this case. Fix this by
1) telling vet which packages are standard;
2) letting vet skip those packages;
3) letting the gccgoimporter handle this case.
As a separate required fix, gccgo/GoLLVM has no runtime/cgo package,
so don't try to depend on it (as it happens, this fixes#25324).
The result is that the cmd/go vet tests pass when using -compiler=gccgo.
Fixes#25324
Change-Id: Iba8f948fe944da5dc674f580bd3321929ee50fa0
Reviewed-on: https://go-review.googlesource.com/113716
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Pick up the changes from CL 114395, CL 114396 and CL 114415.
By re-running govendor in the latest version, some files from
golang.org/x/sys/unix which are ignored for the build also got removed
from the vendored copy.
Updates #25528
Updates #25535
Change-Id: I5c0002fc3a37d6abaafed2e15cc3e2ade803ad7b
Reviewed-on: https://go-review.googlesource.com/114416
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
TestMutexProfile and TestEmptyCallStack couldn't run multiple times
because they mutate state in runtime (mutex profile counters and
a user-defined profile type) and test whether the state
matches what it is supposed to be after the very first run.
We fix TestMutexProfile by relaxing the expected state condition.
We fix TestEmptyCallStack by creating a new profile with a different
name every time the test runs.
For #25520
Change-Id: I8e50cd9526eb650c8989457495ff90a24ce07863
Reviewed-on: https://go-review.googlesource.com/114495
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This changes the http.Transport to flush the bufio.Writer between
writing the request headers and the body.
That wasn't done in the past to minimize the number of TCP packets on
the wire, but that's just an optimization, and it causes problems when
servers are waiting for the headers and the client is blocked on
something before reading the body.
Instead, only do the don't-flush optimization if we know we're not
going to block, whitelisting a set of common in-memory Request.Body
types. (the same set of types special-cased by http.NewRequest)
Fixes#22088
Change-Id: I7717750aa6df32dd3eb92d181b45bc7af24b1144
Reviewed-on: https://go-review.googlesource.com/114316
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Andrew Bonventre <andybons@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Bonventre <andybons@golang.org>
This reverts commit 1764609b8b.
Reason for revert: It breaks the dragonfly trybot, in which there are sometimes (non-deterministically) Events with the same timestamp that have to occur in a specific order.
Change-Id: I714e640c6ab5ccb23d5577e8aa98c7716ede7ad2
Reviewed-on: https://go-review.googlesource.com/114356
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This commit fixes a regression with wasm caused by a367f44c18.
It adds optimizations to the lowering rules of wasm to ensure
that the lowered version of the code generated for write barriers
is simple enough so it can be processed by Liveness.markUnsafePoints.
Change-Id: Ic98f0dd3791fe1df23dcb34d2457fbde7ffce441
Reviewed-on: https://go-review.googlesource.com/114375
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Embedded interfaces in interfaces must take the form of a (possibly
qualified) type name. Before alias types, a type name always denoted
a defined (formerly "named") type. The introduction of alias types
enabled embedding of non-defined types via alias type names, as in:
type T interface { E }
type E interface { m() }
Both cmd/compile and gccgo accept this kind of code, and the spec does
not prohibit it. There may be code in the wild that makes use of this.
go/types was written under the assumption that embedded interfaces
were always defined types; and that assumption was even reflected in
the go/types API.
This change removes this restriction in the implementation (which
happens to make it simpler), and in the API (by adding additional
functions and deprecating the corresponding older versions).
It also replaces uses of NewInterface and Embedded (old API) by
NewInterface2 and EmbeddedType (new API) in dependent packages
(importers).
The old API remains in place for backward compatibility and is marked
as deprecated.
Fixes#25301.
Change-Id: I272acd498754179efaf0590ca49d3eb4eee4348e
Reviewed-on: https://go-review.googlesource.com/114317
Reviewed-by: Alan Donovan <adonovan@google.com>
TestDebugCall* uses atomic spin loops and hence can deadlock if the
garbage collector is enabled (because of #10958; ironically,
implementing debugger call injection is closely related to fixing this
exact issue, but we're not there yet).
Fix this by disabling the garbage collector during these tests.
Updates #25519 (might fix it, though I suspect not)
Change-Id: If1e454b9cdea8e4b1cd82509b762c75b6acd8476
Reviewed-on: https://go-review.googlesource.com/114086
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Apparently a LoadReg can take a Phi as its argument. The Phi has names
in the NamedValue table, so just read the Load's names from the Phi.
The example given, XORKeyStream in chacha20, is pretty complicated so I
didn't try to actually debug it and verify that the results are right.
But the debug logging looks reasonable, with the right names in the right
registers at the right times.
Fixes#25404
Change-Id: I2c3183dcfb033948556d6805bd66c22c0b45625c
Reviewed-on: https://go-review.googlesource.com/114008
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Remove the unexpected function, which is a lot less relevant now that
the generation basically can't detect invalid states, and make sure no
logging appears without -d locationlists=2.
Updates #25404
Change-Id: If3522df5a7397f2e7b43cb808936e319132132b6
Reviewed-on: https://go-review.googlesource.com/114007
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
When the internal/cpu package was introduced, the AES package still used
the custom crypto/internal/cipherhw package for amd64 and s390x. This
change removes that package entirely in favor of directly referencing the
cpu feature flags set and exposed by the internal/cpu package. In
addition, 5 new flags have been added to the internal/cpu s390x struct
for detecting various cipher message (KM) features.
Change-Id: I77cdd8bc1b04ab0e483b21bf1879b5801a4ba5f4
GitHub-Last-Rev: a611e3ecb1
GitHub-Pull-Request: golang/go#24766
Reviewed-on: https://go-review.googlesource.com/105695
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Go's SSA instructions only operate on registers. For example, an add
instruction would read two registers, do the addition and then write
to a register. WebAssembly's instructions, on the other hand, operate
on the stack. The add instruction first pops two values from the stack,
does the addition, then pushes the result to the stack. To fulfill
Go's semantics, one needs to map Go's single add instruction to
4 WebAssembly instructions:
- Push the value of local variable A to the stack
- Push the value of local variable B to the stack
- Do addition
- Write value from stack to local variable C
Now consider that B was set to the constant 42 before the addition:
- Push constant 42 to the stack
- Write value from stack to local variable B
This works, but is inefficient. Instead, the stack is used directly
by inlining instructions if possible. With inlining it becomes:
- Push the value of local variable A to the stack (add)
- Push constant 42 to the stack (constant)
- Do addition (add)
- Write value from stack to local variable C (add)
Note that the two SSA instructions can not be generated sequentially
anymore, because their WebAssembly instructions are interleaved.
Design doc: https://docs.google.com/document/d/131vjr4DH6JFnb-blm_uRdaC0_Nv3OUwjEY5qVCxCup4
Updates #18892
Change-Id: Ie35e1c0bebf4985fddda0d6330eb2066f9ad6dec
Reviewed-on: https://go-review.googlesource.com/103535
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
The upstream pprof implements the readline feature using
the github.com/chzyer/readline package in its pprof.go main.
It would be ideal to use the same readline support package as
the upstream for better user experience and code maintenance.
However, bringing in third-party packages requires more work
than I envisioned (e.g. clean up the vendored code to meet the
expected standard - iow don't break builders).
As a result, this change implements the similar feature
for the pprof command included in the go distribution
(cmd/pprof/pprof.go) using golang.org/x/crypto/ssh/terminal
for now.
Auto-completion is not yet supported (same in the upstream).
The feature is enabled only in linux, windows, darwin, and
only when terminal support is available.
This change brings in new vendored packages,
golang.org/x/crypto/ssh/terminal and
golang.org/x/sys/{unix,windows}.
For #14041
Change-Id: If4a790796acf2ab20f7e81268b9d9354c5a5cd2b
Reviewed-on: https://go-review.googlesource.com/112436
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This partially reverts commit 3bdbb5df76.
The latest CL of js/wasm's file system support does not use
file descriptor mapping any more.
Change-Id: Iaec9c84b392366282cddc69acc75c8a3eb556824
Reviewed-on: https://go-review.googlesource.com/114195
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The current documentation of the WriteTo function is very poor and it
is difficult to deduce how to use it correctly. A good example will
make things much easier.
Fixes#25456
Change-Id: Ibf0c0e153afae8f3e0d7d765d0dc9bcbfd69bfb1
Reviewed-on: https://go-review.googlesource.com/113775
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
When a test binary runs for too long, the go command sends it a
SIGQUIT to force a backtrace dump. On Android, the exec wrapper
will instead receive the signal and dump its backtrace.
Forward SIGQUIT signals from the wrapper to the wrapped process
to gain useful backtraces.
Inspired by issuse 25519; this CL would have revealed the hanging
test directly in the builder log.
Change-Id: Ic362d06940d261374343a1dc09366ef54edaa631
Reviewed-on: https://go-review.googlesource.com/114137
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
While next-ing over a call in gdb, if execution of that call
causes a goroutine's stack to grow (i.e., be moved), gdb loses
track and runs ahead to the next breakpoint, or to the end of
the program, whichever comes first.
Prevent this by preemptively growing the stack so that
ssa/debug_test.go will reliably measure what is intended,
the goodness of line number placement and variable printing.
Fixes#25497.
Change-Id: I8daf931650292a8c8faad2285d7fd405f2157bd2
Reviewed-on: https://go-review.googlesource.com/114080
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
golang.org/cl/37879 unintentionally changed the way NXDOMAIN errors were
handled. Before that change, resolution would fail on the first NXDOMAIN
error and return to the user. After that change, the next server would
be consulted and resolution would fail only after all servers had been
consulted. This change restores the old behavior.
Go 10.10.2:
BenchmarkGoLookupIP-12 10000 174883 ns/op 11450 B/op 163 allocs/op
BenchmarkGoLookupIPNoSuchHost-12 3000 670140 ns/op 52189 B/op 544 allocs/op
BenchmarkGoLookupIPWithBrokenNameServer-12 1 5002568137 ns/op 163792 B/op 375 allocs/op
before this change:
BenchmarkGoLookupIP-12 10000 165501 ns/op 8585 B/op 94 allocs/op
BenchmarkGoLookupIPNoSuchHost-12 1000 1204117 ns/op 83661 B/op 674 allocs/op
BenchmarkGoLookupIPWithBrokenNameServer-12 1 5002629186 ns/op 159128 B/op 275 allocs/op
after this change:
BenchmarkGoLookupIP-12 10000 158102 ns/op 8585 B/op 94 allocs/op
BenchmarkGoLookupIPNoSuchHost-12 2000 645364 ns/op 42990 B/op 356 allocs/op
BenchmarkGoLookupIPWithBrokenNameServer-12 1 5002163437 ns/op 159144 B/op 275 allocs/op
Fixes#25336
Change-Id: I315cd70330d1f66e54ce5a189a61c99f095bc138
Reviewed-on: https://go-review.googlesource.com/113815
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This function checks Request.PostForm, which now includes values parsed
from a PATCH request.
Change-Id: I5d0af58d9c0e9111d4e822c45f0fb1f511bbf0d5
Reviewed-on: https://go-review.googlesource.com/114009
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This change adds Yi8 forms for every ytab that had them before AVX-512 patch.
The rationale is backwards-compatibility.
EVEX forms remain strict and unchanged as they're not bound to any
backwards-compatibility issues.
Fixes#25510
Change-Id: Icd692266010ed64c9fe47cc837afc2edf2ad2d1d
Reviewed-on: https://go-review.googlesource.com/114136
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
The existing code just used timestamps. The new code uses more fields
when timestamps are equal.
Revised to shorten code per reviewer comments.
Change-Id: Ibd0824d0acd7644484d536b1a754a0da156fac3d
Reviewed-on: https://go-review.googlesource.com/113721
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Fixes builders that do not have cgo installed.
Change-Id: I719b7959226b0e67c3ffc11e071784787cabc5ab
Reviewed-on: https://go-review.googlesource.com/114235
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
CL 110555 introduced some changes which were not properly gofmt'ed.
Because the CL was sent via Github the gofmt checks usually performed by
git-codereview didn't catch this (see #24946).
Change-Id: I65c1271620690dbeec88b4ce482d158f7d6df45d
Reviewed-on: https://go-review.googlesource.com/114255
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Windows does not allow to delete opened file.
Fixes#24704
Change-Id: Idfca2d00a2c46bdd9bd2a721478bfd003c474ece
Reviewed-on: https://go-review.googlesource.com/113935
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
There is no NL at the end of README, and that make it strange
when doing "cat misc/android/README".
Change-Id: Ib47953d7b16e8927a4d6be7d5be8de8f2ddbcc39
Reviewed-on: https://go-review.googlesource.com/114010
Reviewed-by: Elias Naur <elias.naur@gmail.com>
The splice syscall is buggy prior to linux 2.6.29. Instead of returning
0 when reading a closed socket, it returns EAGAIN. While it is possible
to detect this (HAProxy falls back to recv), it is simpiler to avoid
using splice all together. the "fcntl(fd, F_GETPIPE_SZ)" syscall is used
detect buggy versions of splice as the syscall returns EINVAL on
versions prior to 2.6.35.
Fixes#25486
Change-Id: I860c029f13de2b09e95a7ba39b76ac7fca91a195
Reviewed-on: https://go-review.googlesource.com/113999
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
In rare circumstances that we don't yet fully understand, the g
register can be spilled to the stack and then reloaded. If this
happens, liveness analysis sees a pointer load into a
non-general-purpose register and panics.
We should fix the root cause of this, but fix the build for now by
ignoring pointer loads into the g register.
For #25504.
Change-Id: I0dfee1af9750c8e9157c7637280cdf07118ef2ca
Reviewed-on: https://go-review.googlesource.com/114081
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
There's semantically-but-not-literally equivalent code in
two cases for joining blocks' value lists in ssa/fuse.go.
It can be made literally equivalent, then commoned up.
Updates #25426.
Change-Id: Id1819366c9d22e5126f9203dcd4c622423994110
Reviewed-on: https://go-review.googlesource.com/113719
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
This moves the bvec hash table logic out of Liveness.compact and into
a bvecSet type. Furthermore, the bvecSet type has the ability to grow
dynamically, which the current implementation doesn't. In addition to
making the code cleaner, this will make it possible to incrementally
compact liveness bitmaps.
Passes toolstash -cmp
Updates #24543.
Change-Id: I46c53e504494206061a1f790ae4a02d768a65681
Reviewed-on: https://go-review.googlesource.com/110176
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Currently Liveness.epilogue makes three passes over the Blocks, but
there's no need to do this. Combine them into a single pass. This
eliminates the need for blockEffects.lastbitmapindex, but, more
importantly, will let us incrementally compact the liveness bitmaps
and significantly reduce allocatons in Liveness.epilogue.
Passes toolstash -cmp.
Updates #24543.
Change-Id: I27802bcd00d23aa122a7ec16cdfd739ae12dd7aa
Reviewed-on: https://go-review.googlesource.com/110175
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Until vgo sorts out and cleans up the vendoring process.
Ran govendor to update packages the cmd/pprof depends on
which resulted in deletion of some of unnecessary files.
Change-Id: Idfba53e94414e90a5e280222750a6df77e979a16
Reviewed-on: https://go-review.googlesource.com/114079
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
On OSX 10.12 and earlier, paired with XCode 9.0,
specifying DWARF version 3 causes dsymutil to misbehave.
Version 2 appears to be good enough to allow processing
of the prologue_end opcode on (at least one version of)
Linux and OSX 10.13.
Fixes#25451.
Change-Id: Ic760e34248393a5386be96351c8e492da1d3413b
Reviewed-on: https://go-review.googlesource.com/114015
Reviewed-by: Alessandro Arzilli <alessandro.arzilli@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Traceback matches the defer stack with the function call stack using
the SP recorded in defer frames when the defer frame is created.
However, on LR machines this is ambiguous: if function A pushes a
defer and then calls function B, where B is a leaf function with a
zero-sized frame, then both A and B have the same SP and will *both*
match the defer on the defer stack. Since traceback unwinds through B
first, it will incorrectly match up the defer with B's frame instead
of A's frame.
Where this goes particularly wrong is if function B causes a signal
that turns into a panic (e.g., a nil pointer dereference). In order to
handle the fact that we may not have a liveness map at the location
that caused the signal and injected a sigpanic call, traceback has
logic to unwind the panicking frame's continuation PC to the PC where
the most recent defer was pushed (this is safe because the frame is
dead other than any defers it pushed). However, if traceback
mis-matches the defer stack, it winds up reporting the B's
continuation PC is in A. If the runtime then uses this continuation PC
to look up PCDATA in B, it will panic because the PC is out of range
for B. This failure mode can be seen in
sync/atomic/atomic_test.go:TestNilDeref. An example failure is:
https://build.golang.org/log/8e07a762487839252af902355f6b1379dbd463c5
This CL fixes all of this by recognizing that a function that pushes a
defer must also have a non-zero-sized frame and using this fact to
refine the defer matching logic.
Fixes the build for arm64, mips, mipsle, ppc64, ppc64le, and s390x.
Fixes#25499.
Change-Id: Iff7c01d08ad42f3de22b3a73658cc2f674900101
Reviewed-on: https://go-review.googlesource.com/114078
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Needs the go compiler to be build with GOEXPERIMENT=debugcpu to be active.
The GODEBUGCPU environment variable can be used to disable usage of
specific processor features in the Go standard library.
This is useful for testing and benchmarking different code paths that
are guarded by internal/cpu variable checks.
Use of processor features can not be enabled through GODEBUGCPU.
To disable usage of AVX and SSE41 cpu features on GOARCH amd64 use:
GODEBUGCPU=avx=0,sse41=0
The special "all" option can be used to disable all options:
GODEBUGCPU=all=0
Updates #12805
Updates #15403
Change-Id: I699c2e6f74d98472b6fb4b1e5ffbf29b15697aab
Reviewed-on: https://go-review.googlesource.com/91737
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This makes the checking of build tags in file names consistent to that of the build tags in `// +build` line.
Fixed#25461
Change-Id: Iba14d1050f8aba44e7539ab3b8711af1980ccfe4
GitHub-Last-Rev: 11b14e239d
GitHub-Pull-Request: golang/go#25480
Reviewed-on: https://go-review.googlesource.com/113818
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The added fields are used in buildExtensions so
should be documented too.
Fixes#21363
Change-Id: Ifcc11da5b690327946c2488bcf4c79c60175a339
Reviewed-on: https://go-review.googlesource.com/113916
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
