The String method is n-squared and overwrites its receiver.
Fix both issues, with only a slight loss of clarity.

Fixes #28773

Change-Id: I588f69d4cbd72931b28b984671512834473bd466
Reviewed-on: https://go-review.googlesource.com/c/151217Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

TestImportTableInUnknownSection was introduced in CL 110555 to
test PE executable with import table located in section other than
".idata". We used atmfd.dll for that purpose, but it seems
atmfd.dll is not present on some systems.

Use kernel32.dll instead. kernel32.dll import table is located in
".rdata" section, so it should do the job. And every Windows
system has kernel32.dll file.

Also make TestImportTableInUnknownSection run on windows-arm,
since windows-arm should also have kernel32.dll file.

Updates #27904

Change-Id: Ie005ee10e46ae0c06e83929d581e89f86c051eea
Reviewed-on: https://go-review.googlesource.com/c/151137
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This makes it easier to track names of function arguments
for debugging purposes.

Change-Id: Ic34856fe0b910005e1c7bc051d769d489a4b158e
Reviewed-on: https://go-review.googlesource.com/c/150098
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

This CL adds a button that collapses values list of a block.
Button is displayed for every block with non-empty values.

Change-Id: I4b65af81e25349f38341df487d42698c9d006a00
Reviewed-on: https://go-review.googlesource.com/c/144557
Run-TryBot: Yury Smolsky <yury@smolsky.by>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

On some platforms, assembly in internal/syscall/unix references
unexported runtime symbols. Catch these references so the compiler can
generate the necessary ABI wrappers.

Fixes #28769.
Updates #27539.

Change-Id: I118eebfb8b3d907b4c3562198e6afb49854f5827
Reviewed-on: https://go-review.googlesource.com/c/149817
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Clément Chigot <clement.chigot@atos.net>
Reviewed-by: Keith Randall <khr@golang.org>

When using softfloat, floating point ops are rewritten to integer
ops. The types of store ops were not rewritten. This may lower
to floating point stores, which are problematic. This CL fixes
this by rewriting the store types as well.

This fixes test/fixedbugs/issue28688.go on Wasm. Softfloat mode
is not used by default on Wasm, and it is not needed as Wasm spec
supports floating points. But it is nice to have the correct
types.

Change-Id: Ib5e19e19fa9491b15c2f60320f8724cace5cefb5
Reviewed-on: https://go-review.googlesource.com/c/149965
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

UserHomeDir used to return an empty string if the corresponding
environment variable was not set. Changed it to return an error if the
variable is not set, to have the same signature and behaviour as UserCacheDir.

Fixes #28562

Change-Id: I42c497e8011ecfbbadebe7de1751575273be221c
Reviewed-on: https://go-review.googlesource.com/c/150418
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

The performance improvement is not as big as we hoped.
Until the API is feature complete, we postpone the release
and avoid added complexity.

This change was prepared by reverting all the changes affected
src/cmd/trace and src/internal/traceparser packages after
golang.org/cl/137635, and then bringing back MMU computation
APIs (originally in src/internal/traceparser) to the
src/internal/trace package.

Revert "cmd/trace: use new traceparser to parse the raw trace files"
This reverts https://golang.org/cl/145457
  (commit 08816cb8).

Revert "internal/traceparser: provide parser that uses less space and parses segments of runtime trace files"
This reverts https://golang.org/cl/137635
  (commit daaf361f).

Change-Id: Ic2a068a7dbaf4053cd9674ca7bde9c58e74385b4
Reviewed-on: https://go-review.googlesource.com/c/150517
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

CL 150497 enabled TestRemoveAllDot on "noat" systems.

However, this test is failing on Plan 9 because the rmdir
system call allows to remove "." on Plan 9.

This change prevents the "noat" implementation of RemoveAll to
remove ".", so it remains consistent with the "at" implementation.

Fixes #28903.

Change-Id: Ifc8fe36bdd8053a4e416f0590663c844c97ce72a
Reviewed-on: https://go-review.googlesource.com/c/150621
Run-TryBot: David du Colombier <0intro@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This case was missed entirely and caused such params to be
unprintable.  This change gives them stack addresses
for the entire function (which is correct).

Change-Id: Ia4f706450219e48bce65b6395d3d9792df142fb5
Reviewed-on: https://go-review.googlesource.com/c/150657
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>

CL 142517 has used some formats incorrectly. This change fixes it
by using %v for errors and invoking Block.Kind.String().
Format map stays intact.

Updates #28177

Change-Id: If53b6cc54ba3c1ffc17b005225787e3b546de404
Reviewed-on: https://go-review.googlesource.com/c/150798
Run-TryBot: Yury Smolsky <yury@smolsky.by>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

This adds a debug check to throw immediately if any pointers are added
to the gcWork buffer after the mark completion barrier. The intent is
to catch the source of the cached GC work that occasionally produces
"P has cached GC work at end of mark termination" failures.

The result should be that we get "throwOnGCWork" throws instead of "P
has cached GC work at end of mark termination" throws, but with useful
stack traces.

This should be reverted before the release. I've been unable to
reproduce this issue locally, but this issue appears fairly regularly
on the builders, so the intent is to catch it on the builders.

This probably slows down the GC slightly.

For #27993.

Change-Id: I5035e14058ad313bfbd3d68c41ec05179147a85c
Reviewed-on: https://go-review.googlesource.com/c/149969
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

For #27993.

Change-Id: I20127e8a9844c2c488f38e1ab1f8f5a27a5df03e
Reviewed-on: https://go-review.googlesource.com/c/149968
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #28904

Change-Id: I8d416c47479a266735a39c926fd2f0f2bb25d57b
GitHub-Last-Rev: 3a7865a5be27937833cf4f65c242c639e51665c4
GitHub-Pull-Request: golang/go#28907
Reviewed-on: https://go-review.googlesource.com/c/150737Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This CL adds CFGs to ssa.html.
It execs dot to generate SVG,
which then gets inlined into the html.
Some standard naming and javascript hacks
enable integration with the rest of ssa.html.
Clicking on blocks highlights the relevant
part of the CFG, and vice versa.

Sample output and screenshots can be seen in #28177.

CFGs can be turned on with the suffix mask:
:*            - dump CFG for every phase
:lower        - just the lower phase
:lower-layout - lower through layout
:w,x-y        - phases w and x through y

Calling dot after every pass is noticeably slow,
instead use the range of phases.

Dead blocks are not displayed on CFG.

User can zoom and pan individual CFG
when the automatic adjustment has failed.

Dot-related errors are reported
without bringing down the process.

Fixes #28177

Change-Id: Id52c42d86c4559ca737288aa10561b67a119c63d
Reviewed-on: https://go-review.googlesource.com/c/142517
Run-TryBot: Yury Smolsky <yury@smolsky.by>
Reviewed-by: David Chase <drchase@google.com>

In race mode, these functions are defined and declared in
different packages, which therefore don't have implicit arg maps.
When they are defer'd, and the stack needs to move, the runtime
fails with missing stack maps. This CL adds arg maps (FUNCDATA)
to them.

Updates #28848

Change-Id: I0271563b7e78e7797ce2990c303dced957efaa86
Reviewed-on: https://go-review.googlesource.com/c/150457
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Using fmt.Scanln in a browser environment caused a panic, since there
was no stub for fs.read. This commit adds a stub that returns ENOSYS.

Fixes #27773.

Change-Id: I79b019039e4bc90da51d71a4edddf3bd7809ff45
Reviewed-on: https://go-review.googlesource.com/c/150617
Run-TryBot: Richard Musiol <neelance@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The playground is not using GOOS=js, so it is not able to use the
package syscall/js. Examples that depend on syscall/js should not
show a "Run" button.

Fixes #28526.

Change-Id: I8b2fcdd0c0ee517a5c3864bf459f813129542389
Reviewed-on: https://go-review.googlesource.com/c/148918Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Return a PathError instead of an unwrapped syscall.EINVAL if the path
ends with dots.

As suggested by Roger Peppe in CL 150158.

Change-Id: I4d82a6ff64a979b67a843a1cc4fea58ed9326aed
Reviewed-on: https://go-review.googlesource.com/c/150160
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Prohibiting RemoveAll with paths that end in ".." was added with
CL 137442 in this release cycle, but it worked before and it should
continue to work.

Also run TestRemoveAllDot on all systems; the test is not specific to
the use of unlinkat and friends.

Change-Id: I277784c8915cd748fec318d2936062440d5d1fde
Reviewed-on: https://go-review.googlesource.com/c/150497Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>

CL 150417 was submitted before I could recommend this change to remove
an unnecessary allocation.

Updates #28849

Change-Id: I4cd655f62bb3d00eda6c997f074785385bceee0c
Reviewed-on: https://go-review.googlesource.com/c/150498Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The js/wasm architecture does not support signals at all, but there are
already some signal constants defined because of stdlib dependencies.
This change adds a dummy constant for syscall.SIGTERM as well, to make
js/wasm compatible with more existing Go code.

There is the Go proverb "Syscall must always be guarded with build
tags.", so code should not expect syscall.SIGTERM to exist. Still,
adding SIGTERM should do more good than harm.

Fixes #28719.

Change-Id: I3554b484f96a21427491c04eb1dd57e7af5bd62f
Reviewed-on: https://go-review.googlesource.com/c/150477
Run-TryBot: Richard Musiol <neelance@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

os.TempDir() did not return a proper directory on Windows with js/wasm,
because js/wasm only uses the Unix variant of TempDir.

This commit passes the temporary directory provided by Node.js to the
Go runtime by adding it as a default value for the TMPDIR environment
variable. It makes TempDir compatible with all platforms.

Fixes #27306.

Change-Id: I8b17e44cfb2ca41939ab2a4f918698fe330cb8bc
Reviewed-on: https://go-review.googlesource.com/c/150437
Run-TryBot: Richard Musiol <neelance@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

We should be able to build docker after this get applied.

Updates #13192

Change-Id: I5378d3518fac52d6bd4c97828884c1b382b7ace5
GitHub-Last-Rev: 210b7bc2e172f641f1102982e04542bf73a1aa46
GitHub-Pull-Request: golang/go#28546
Reviewed-on: https://go-review.googlesource.com/c/146898Reviewed-by: Jiang Ma <ma.jiang@zte.com.cn>
Reviewed-by: Clément Chigot <clement.chigot@atos.net>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

FormatMediaType used rune&0x80==0 to check if parameter values consisted
of valid ascii charaters. Comparing strings using their runes instead of
their bytes leads to some non-ascii strings to pass as valid.

E.g. the rune for 'Ą' is 0x104, 0x104 & 0x80 => 0. Its byte
representation is 0xc4 0x84, both of which result in non zero values
when masked with 0x80

Fixes #28849

Change-Id: Ib9fb4968bcbbec0197d81136f380d40a2a56c14b
Reviewed-on: https://go-review.googlesource.com/c/150417
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

ValueOf() panics if x is not one of the expected types.

Change-Id: I1105e46bd09a5ab13c162b77c1c50cc45bce27a2
GitHub-Last-Rev: 34a88ce8206954d94f0a884ab7f6494116c54a2d
GitHub-Pull-Request: golang/go#28846
Reviewed-on: https://go-review.googlesource.com/c/150138Reviewed-by: Richard Musiol <neelance@gmail.com>

This commit performs replace double quote to backquote,
so now all examples looks consistent.

Change-Id: I8cf760ce1bdeff9619a88e531161b9516385241b
GitHub-Last-Rev: e3e636cebbf41528b8a73f9a3fe5afa10876f964
GitHub-Pull-Request: golang/go#28879
Reviewed-on: https://go-review.googlesource.com/c/150397Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #27619

Change-Id: If18df696c0778efe894a4a249d4964db1b02e5d6
Reviewed-on: https://go-review.googlesource.com/c/150159Reviewed-by: Yuval Pavel Zholkover <paulzhol@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I7a1046f5e0aedbbdd1106a616de410fe4e0cb7d8
Reviewed-on: https://go-review.googlesource.com/c/92295
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This commit adds examples for Match, Find,
FindAllSubmatch, FindSubmatch and Match functions.

Change-Id: I2bdf8c3cee6e89d618109397378c1fc91aaf1dfb
GitHub-Last-Rev: 33f34b7adca2911a4fff9638c93e846fb0021465
GitHub-Pull-Request: golang/go#28837
Reviewed-on: https://go-review.googlesource.com/c/150020
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I70afd2f7b6783926174c4e66565b711cffeb97c5
Reviewed-on: https://go-review.googlesource.com/c/150141
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Per https://semver.org/#spec-item-10, build metadata may include
a series of dot separated identifiers.

Fixes #28647

Change-Id: I98655c62584a822953df71fba32b4a2cafe7a04b
Reviewed-on: https://go-review.googlesource.com/c/148835Reviewed-by: Bryan C. Mills <bcmills@google.com>

cmd/vet, now simplified to a single function call is now authoritative,
not a copy of vet-lite.

The update-xtools.sh script now uses the imports of cmd/vet as the
roots for vendoring.

Change-Id: I4faef3fcf3db10b3a3930726e8d0720a3c8395da
Reviewed-on: https://go-review.googlesource.com/c/150297
Run-TryBot: Alan Donovan <adonovan@google.com>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>

- restore and rework cmd/vet/doc.go, which was clobbered during the vet-lite switch.
- document go vet -vettool=prog flag and how to run an alternative checker.
- make 'go vet -help' show how to list vet tool's flags.  Example:

	$ go vet -help
	usage: go vet [-n] [-x] [-vettool prog] [build flags] [vet flags] [packages]
	Run 'go help vet' for details.
	Run 'go tool vet help' for the vet tool's flags.

	$ go vet -vettool=~/bin/myvet -help
	usage: go vet [-n] [-x] [-vettool prog] [build flags] [vet flags] [packages]
	Run 'go help vet' for details.
	Run '~/bin/myvet help' for the vet tool's flags.

Updates #28840

Change-Id: Ieb79dfe29e1df074f865bc9a9d47b44199675d7d
Reviewed-on: https://go-review.googlesource.com/c/147018Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Mainly to pull the fix for the regression in #28792.

Change-Id: If71ae783fd9a9e3935186b49fdf501ba098235a2
Reviewed-on: https://go-review.googlesource.com/c/150161
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>

This change does a bulk rename of several identifiers in the compiler.
See #27167 and https://docs.google.com/document/d/19_ExiylD9MRfeAjKIfEsMU1_RGhuxB9sA0b5Zv7byVI/
for context and for discussion of these particular renames.

Commands run to generate this change:

gorename -from '"cmd/compile/internal/gc".OPROC' -to OGO
gorename -from '"cmd/compile/internal/gc".OCOM' -to OBITNOT
gorename -from '"cmd/compile/internal/gc".OMINUS' -to ONEG
gorename -from '"cmd/compile/internal/gc".OIND' -to ODEREF
gorename -from '"cmd/compile/internal/gc".OARRAYBYTESTR' -to OBYTES2STR
gorename -from '"cmd/compile/internal/gc".OARRAYBYTESTRTMP' -to OBYTES2STRTMP
gorename -from '"cmd/compile/internal/gc".OARRAYRUNESTR' -to ORUNES2STR
gorename -from '"cmd/compile/internal/gc".OSTRARRAYBYTE' -to OSTR2BYTES
gorename -from '"cmd/compile/internal/gc".OSTRARRAYBYTETMP' -to OSTR2BYTESTMP
gorename -from '"cmd/compile/internal/gc".OSTRARRAYRUNE' -to OSTR2RUNES

gorename -from '"cmd/compile/internal/gc".Etop' -to ctxStmt
gorename -from '"cmd/compile/internal/gc".Erv' -to ctxExpr
gorename -from '"cmd/compile/internal/gc".Ecall' -to ctxCallee
gorename -from '"cmd/compile/internal/gc".Efnstruct' -to ctxMultiOK
gorename -from '"cmd/compile/internal/gc".Easgn' -to ctxAssign
gorename -from '"cmd/compile/internal/gc".Ecomplit' -to ctxCompLit

Not altered: parameters and local variables (mostly in typecheck.go) named top,
which should probably now be called ctx (and which should probably have a named type).
Also not altered: Field called Top in gc.Func.

gorename -from '"cmd/compile/internal/gc".Node.Isddd' -to IsDDD
gorename -from '"cmd/compile/internal/gc".Node.SetIsddd' -to SetIsDDD
gorename -from '"cmd/compile/internal/gc".nodeIsddd' -to nodeIsDDD
gorename -from '"cmd/compile/internal/types".Field.Isddd' -to IsDDD
gorename -from '"cmd/compile/internal/types".Field.SetIsddd' -to SetIsDDD
gorename -from '"cmd/compile/internal/types".fieldIsddd' -to fieldIsDDD

Not altered: function gc.hasddd, params and local variables called isddd
Also not altered: fmt.go prints nodes using "isddd(%v)".

cd cmd/compile/internal/gc; go generate

I then manually found impacted comments using exact string match
and fixed them up by hand. The comment changes were trivial.

Passes toolstash-check.

Fixes #27167. If this experiment is deemed a success,
we will open a new tracking issue for renames to do
at the end of the 1.13 cycles.

Change-Id: I2dc541533d2ab0d06cb3d31d65df205ecfb151e8
Reviewed-on: https://go-review.googlesource.com/c/150140
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Fixes #28834

Change-Id: I95d6874e62d36974415f43843881a4ae85b3c7ce
Reviewed-on: https://go-review.googlesource.com/c/149964
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Alan Donovan <adonovan@google.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

CL 146020 changed the behavior of RemoveAll("") on unix systems using
the *at functions to return syscall.EINVAL instead of nil. Adjust the
*at implementation to retain this behavior as is the case on the *noat
systems.

Additionally, also make sure RemoveAll("") on systems not using the "at
functions (e.g. nacl and js/wasm) follow the same behavior (which wasn't
the case previously).

Fixes #28830

Change-Id: I8383c1423fefe871d18ff49134a1d23077ec6867
Reviewed-on: https://go-review.googlesource.com/c/150158
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: roger peppe <rogpeppe@gmail.com>

Procedure names should reflect what they do; function names
should reflect what they return. Functions are used in
expressions, often in things like if's, so they need
to read appropriately.

        if CheckHMAC(a, b, key)

is unhelpful because we can't deduce whether CheckHMAC
returns true on error or non­-error; instead

        if ValidHMAC(a, b, key)

makes the point clear and makes a future mistake
in using the routine less likely.

https://www.lysator.liu.se/c/pikestyle.html

Change-Id: I7c4b1981c90c8d7475ddd8ec18dee3db2e0f42df
GitHub-Last-Rev: 32199a418b5e5507259fa4b6715da8a9c185f90a
GitHub-Pull-Request: golang/go#28823
Reviewed-on: https://go-review.googlesource.com/c/149857Reviewed-by: Filippo Valsorda <filippo@golang.org>

CL 138675 added a call to runtime.save_g which uses thread local
storage to store g. On iOS however, that storage was not initialized
 yet. Move the call to below _cgo_init where it is set up.

Change-Id: I14538d3e7d56ff35a6fa02c47bca306d24c38010
Reviewed-on: https://go-review.googlesource.com/c/150157
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>