Presumably each line in the descriptor should match the corresponding operation.
Change-Id: I7726befcd62147324764d15c26e737357122be51
GitHub-Last-Rev: 85e610e304
GitHub-Pull-Request: golang/go#24807
Reviewed-on: https://go-review.googlesource.com/106355
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The previous implementation would return "sql: Rows are closed" for any
context errors, which can be confusing for context timeouts or
cancelations.
Fixes#24431
Change-Id: I884904ec43204c43f4e94e2335b2802aab77a888
Reviewed-on: https://go-review.googlesource.com/104276
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
It wasn't clear for existing docs if DB.Close forcefully closed
connections or waited for them to finish.
Fixes#23753
Change-Id: Id7df31224c93181c8d01bab7b0b23da25b42a288
Reviewed-on: https://go-review.googlesource.com/103397
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The process reading the output of the binary may read stderr and
stdout separately, and may interleave reads from the two streams
arbitrarily. Because we explicitly serialize writes on the writer
side, we can reuse a timestamp within a single stream without losing
information; however, if we use the same timestamp for write on both
streams, the reader can't tell how to interleave them.
This change ensures that every time we change between the two fds, we
also bump the timestamp. That way, writes within a stream continue to
show the same timestamp, but a sorted merge of the contents of the two
streams always interleaves them in the correct order.
This still requires a corresponding change to the Playground parser to
actually reconstruct the correct interleaving. It currently merges the
two streams without reordering them; it should instead buffer them
separately and perform a sorted merge. (See
https://golang.org/cl/105496.)
Updates golang/go#24615.
Updates golang/go#24659.
Change-Id: Id789dfcc02eb4247906c9ddad38dac50cf829979
Reviewed-on: https://go-review.googlesource.com/105235
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Yury Smolsky <yury@smolsky.by>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Mac otool and llvm-objdump distinguishes a Mach-O section is
text or data by looking at S_ATTR_PURE_INSTRUCTIONS bit. Without
this bit it thinks our function symbols are data, not functions.
Set this bit for text section to make otool/objdump happy.
Fixes#24706.
Change-Id: I5236482cb9a72474c23fbea0f35d5b5cc8491ea4
Reviewed-on: https://go-review.googlesource.com/105256
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
If NewFile is called with a file descriptor that is already set to
non-blocking mode, it tries to return a pollable file (one for which
SetDeadline methods work) by adding the filedes to the poll/netpoll
mechanism. If called with a filedes in blocking mode, it returns a
non-pollable file, as it always did.
Fixes#22939
Updates #24331
Change-Id: Id54c8be1b83e6d35e14e76d7df0e57a9fd64e176
Reviewed-on: https://go-review.googlesource.com/100077
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
When a neither of a conditional block's successors follows,
the block must end with a conditional branch followed by a
an unconditional branch. If the (conditional) branch is
"unlikely", invert it and swap successors to make it
likely instead.
This doesn't matter to most benchmarks on amd64, but in one
instance on amd64 it caused a 30% improvement, and it is
otherwise harmless. The problematic loop is
for i := 0; i < w; i++ {
if pw[i] != 0 {
return true
}
}
compiled under GOEXPERIMENT=preemptibleloops
This the very worst-case benchmark for that experiment.
Also in this CL is a commoning up of heavily-repeated
boilerplate, which made it much easier to see that the
changes were applied correctly. In the future this should
allow un-exporting of SSAGenState.Branches once the
boilerplate-replacement is done everywhere.
Change-Id: I0e5ded6eeb3ab1e3e0138e12d54c7e056bd99335
Reviewed-on: https://go-review.googlesource.com/104977
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TestServerDuplicateBackgroundRead has been causing crashes on the
netbsd-arm-bsiegert builder, with the system becoming completely
unresponsive (probably deadlocked). Skip this test while the crash
is under investigation.
Upstream bug report is http://gnats.netbsd.org/53173.
Change-Id: Ib48f19005cf2cbba8a27e75e689c2acb025d8870
Reviewed-on: https://go-review.googlesource.com/106295
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
And delete them from asm_test.
Also delete an arm64 cmov test has been already ported to the new test
harness.
Change-Id: I4458721e1f512bc9ecbbe1c22a2c9c7109ad68fe
Reviewed-on: https://go-review.googlesource.com/106335
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Giovanni Bajo <rasky@develer.com>
SWPD/SWPW/SWPH/SWPB were introduced in ARMv8.1. They swap content
of register and memory atomically. And their difference is
SWPD: 64-bit double word data
SWPW: 32-bit word data (zero extended to 64-bit)
SWPH: 16-bit half word data (zero extended to 64-bit)
SWPB: 8-bit byte data (zero extended to 64-bit)
This CL implements them in the arm64 assembler.
Change-Id: I2d9fb2310674bd92693531210e187143e7eed602
Reviewed-on: https://go-review.googlesource.com/101516
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
In #17528 it was discussed (off-topic to the actual issue) to reserve
GOARCH names for the RISC-V architecture. With the first RISC-V
Linux-capable development boards released (e.g. HiFive Unleashed),
Linux distributions being ported to RISC-V (e.g. Debian, Fedora) and
RISC-V support being added to gccgo (CL 96377), it becomes more likely
that Go software (and maybe Go itself) will be ported as well.
Add riscv and riscv64 (which is already used by gccgo), so Go 1.11 will
already recognize "*_riscv{,64}.go" as reserved files.
Change-Id: I042aab19c68751d82ea513e40f7b1d7e1ad924ea
Reviewed-on: https://go-review.googlesource.com/106256
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The patch adds support for arm64 instructions LDRB, LDRH, LDRSB,
LDRSH, LDRSW, STR, STRB and STRH with register offset.
Test cases are also added.
Change-Id: I8d17fddd2963c0bc366e12b00bac49b93f3f0957
Reviewed-on: https://go-review.googlesource.com/91575
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
After CL 104636 cpu.X86.HasAVX is set early enough that it can be used
to determine useAVXmemmove. Use it and remove support_avx.
Change-Id: Ib7a627bede2bf96c92362507e742bd833cb42a74
Reviewed-on: https://go-review.googlesource.com/106235
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Also, make the variables list sorted.
Fixes#24794
Change-Id: I55f77004b00391875d26df8e55e54d79cef168dc
Reviewed-on: https://go-review.googlesource.com/106255
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Point out that one can just run the commands now; it's not necessary
to log out first.
Change-Id: I48d0cc0273d97ba54ce59b3a3bbcae0b5af9aaef
Reviewed-on: https://go-review.googlesource.com/106195
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Fixes#23617
Note that this CL does not affect darwin/arm and darwin/arm64,
still TBD what, if anything, needs to be done for those.
This is a fix of CL 105975 which was reverted in CL 106155.
Needed to use movl instead of movq for 386.
Change-Id: I0db7f8087173869e60cc22c6c3124fa0a0739b46
Reviewed-on: https://go-review.googlesource.com/106156
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The check was previously disallowing package main from even importing
a non-function symbol named "main".
Fixes#24801.
Change-Id: I849b9713890429f0a16860ef16b5dc7e970d04a4
Reviewed-on: https://go-review.googlesource.com/106120
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
We'll always generate method expression wrappers for declared
interface types in their own package, so no need to generate them in
downstream packages.
Noticed by gri@ while looking into #21282.
Change-Id: I4fb7051b4e15297933da05fdd2b111d6b8f4178e
Reviewed-on: https://go-review.googlesource.com/106175
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
Previously, we used to associate a function with its first returned type
assuming that it is a factory function for that type.
However, a function may return multiple types in which case it is usually
doing something else. Check for multiple return types, and treat it as
a normal function in that case. Maintain same behavior if the function
returns just one type.
Fixes#12839
Change-Id: Ic4ac11d322996f216f593b71f4e61ad4270d5213
Reviewed-on: https://go-review.googlesource.com/105575
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
/spanio, /spanblock, /spansched, /spansyscall provide
the pprof-style summary of span execution's
io, block, scheduling, syscall latency distributions
respectively.
The computation logic for /io, /block, /sched, /syscall
analysis was refactored and extended for reuse in these
new types of analysis. Upon the analysis query, we create
a map of goroutine id to time intervals based on the query
parameter, that represents the interesting time intervals
of matching goroutines. Only the events from the matching
goroutines that fall into the intervals are considered
in the pprof computation.
The new endpoints are not yet hooked into other span
analysis page (e.g. /userspan) yet.
Change-Id: I80c3396e45a2d6631758710de67d132e5832c7ce
Reviewed-on: https://go-review.googlesource.com/105822
Reviewed-by: Heschi Kreinick <heschi@google.com>
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This reverts commit 76e92d1c9e.
Reason for revert: Seems to have broken the darwin/386 builder, the toolchain is barfing on the new inline assembly.
Change-Id: Ic83fa3c85148946529c5fd47d1e1669898031ace
Reviewed-on: https://go-review.googlesource.com/106155
Reviewed-by: Keith Randall <khr@golang.org>
All tests involving trace collection and parsing
still need handling of failures caused by #16755
(Timestamp issue)
Fixes#24738
Change-Id: I6cd0f9c6f49854a22fad6fce1a00964c168aa614
Reviewed-on: https://go-review.googlesource.com/105821
Reviewed-by: Peter Weinberger <pjw@google.com>
The docs for ResponseWriter.Write say
// If the Header
// does not contain a Content-Type line, Write adds a Content-Type set
// to the result of passing the initial 512 bytes of written data to
// DetectContentType.
The header X-Content-Type-Options:nosniff is an explicit directive that
content-type should not be sniffed.
This changes the behavior of Response.WriteHeader so that, when
there is an X-Content-Type-Options:nosniff header, but there is
no Content-type header, the following happens:
1. A Content-type:application/octet-stream is added
2. A warning is logged via the server's logging mechanism.
Previously, a content-type would have been silently added based on
heuristic analysis of the first 512B which might allow a hosted
GIF like http://www.thinkfu.com/blog/gifjavascript-polyglots to be
categorized as JavaScript which might allow a CSP bypass, loading
as a script despite `Content-Security-Policy: script-src 'self' `.
----
https://fetch.spec.whatwg.org/#x-content-type-options-header
defines the X-Content-Type-Options header.
["Polyglots: Crossing Origins by Crossing Formats"](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.905.2946&rep=rep1&type=pdf)
explains Polyglot attacks in more detail.
Change-Id: I2c8800d2e4b4d10d9e08a0e3e5b20334a75f03c0
Reviewed-on: https://go-review.googlesource.com/89275
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
To enable the exec wrapper go_darwin_arm_exec.go to run binaries
on iOS devices, the GOIOS_DEV_ID variable needs to be set to a code
signing identity. The program detect.go attempts to detect suitable
values for GOIOS_DEV_ID (along with GOIOS_APP_ID and GOIOS_TEAM_ID).
Before this change, detect.go would use "security find-identity
-p codesigning -v" to list all available identities for code signing
and pick the first one with "iPhone Developer" in its name. However,
that pick might be invalid since if it was replaced by an identity
issued later.
For example, on the mobile builder:
$ security find-identity -p codesigning -v
1) 0E251DE41FE4490574E475AC320B47F58D6D3635 "lldb_codesign"
2) 0358588D07AA6A19478981BA405F40A97F95F187 "iPhone Developer: xxx@xxx (2754T98W8E)"
3) FC6D96F24A3223C98BF7A2C2C5194D82E04CD23E "iPhone Developer: xxx@xxx (2754T98W8E)"
3 valid identities found
In this case, the identity 0358588D07AA6A19478981BA405F40A97F95F187
is picked by detect.go even though it has been invalidated by
FC6D96F24A3223C98BF7A2C2C5194D82E04CD23E.
Instead of attempting to find an identity from the "security
find-identity" list, use the identity from the CommonName in the
embedded certificate in the provisioning file. The CommonName only
lists the identity name (iPhone Developer: xxx@xxx (2754T98W8E)),
not the fingerprint (FC6D96F24A3223C98BF7A2C2C5194D82E04CD23E), but
fortunately the codesign tool accepts both.
Identity names may not be unique, as demonstrated by the example,
but that will result in an ambiguity error at codesigning instead of
a more obscure error about an invalid identity when
go_darwin_arm_exec.go runs a binary.
The fix is then to delete the invalid identity from the system
keychain.
While here, find all connected devices instead of the first connected
and only consider provision files that covers them all. This matters
for the mobile builder where two devices are connected.
Change-Id: I6beb59ace3fc5e071ba76222a20a607765943989
Reviewed-on: https://go-review.googlesource.com/105436
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
After CL 104636 the feature flags in internal/cpu are initialized before
alginit and can now be used for aeshash feature detection. Also remove
now unused runtime variables:
x86:
support_ssse3
support_sse42
support_aes
arm64:
support_aes
Change-Id: I2f64198d91750eaf3c6cf2aac6e9e17615811ec8
Reviewed-on: https://go-review.googlesource.com/106015
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Once upon a time, the iOS exec wrapper needed to change the current
working directory for the binary being tested. To allow that, the
runtime raised a SIGINT signal that the wrapper caught, changed the
working directory and resumed the process.
These days, the current working directory is passed from the wrapper
to the runtime through a special entry in the app metadata and the
SIGINT handshake is not necessary anymore.
Remove the signaling from the runtime and the exec harness.
Change-Id: Ia53bcc9e4724d2ca00207e22b91ce80a05271b55
Reviewed-on: https://go-review.googlesource.com/106096
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Use constant masks and align the definition of isSet with
arm64 and ppc64x.
Change-Id: I0c6eae30da5e3ce797cde0dab4a39855d4d245d9
Reviewed-on: https://go-review.googlesource.com/94759
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
runtime.alginit needs runtime/support_{aes,ssse3,sse41} feature flag
to init aeshash function but internal/cpu.init not be called yet.
This CL will call internal/cpu.initialize before runtime.alginit, so
that we can move all cpu features related code to internal/cpu.
Change-Id: I00b8e403ace3553f8c707563d95f27dade0bc853
Reviewed-on: https://go-review.googlesource.com/104636
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
When I added the Node.copy method, I converted most of the occurrences
but missed a few.
One of them, used only for gdata, was an unnecessary copy given that
gdata does not modify the node it is passed.
No allocation changes in compilebench.
Passes toolstash -cmp on std cmd.
Change-Id: I7fba5212377b75c6d6b3785e594a30568ff0732e
Reviewed-on: https://go-review.googlesource.com/104937
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
EM_AARCH64 is defined as a constant, but the corresponding entry in
machineStrings is missing. Add it.
Change-Id: I6506404386efe608877095e635a290bbc0686215
Reviewed-on: https://go-review.googlesource.com/106035
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The code reading these variables was removed in CL 41476. They are only
set but never read now, so remove them.
Change-Id: I6b0b8d813e9a3ec2a13586ff92746e00ad1b5bf0
Reviewed-on: https://go-review.googlesource.com/106095
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Fixes#23617
Note that this CL does not affect darwin/arm and darwin/arm64,
still TBD what, if anything, needs to be done for those.
Change-Id: Ie1ee02a9f4d4d1fb9cd5dc432d900f926cc157db
Reviewed-on: https://go-review.googlesource.com/105975
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Packages imported by the runtime should follow the same memory
allocation rules as the runtime package.
Change-Id: Id3fadb05605acbd6ac61d7fe6068a2add8bb2308
Reviewed-on: https://go-review.googlesource.com/105995
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
And delete them from asm_test.
Change-Id: I24f421b87e8cb4770c887a6dfd58eacd0088947d
Reviewed-on: https://go-review.googlesource.com/106056
Reviewed-by: Keith Randall <khr@golang.org>
And delete them from asm_test.
Change-Id: I9a75efe9858ef9d7ac86065f860c2ae3f25b0941
Reviewed-on: https://go-review.googlesource.com/105597
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Also, when statically building itabs, compare *types.Sym instead of
name alone so that method sets with duplicate non-exported methods are
handled correctly.
Fixes#24693.
Change-Id: I2db8a3d6e80991a71fef5586a15134b6de116269
Reviewed-on: https://go-review.googlesource.com/105039
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
A package's height is defined as the length of the longest import path
between itself and a leaf package (i.e., package with no imports).
We can't rely on knowing the path of the package being compiled, so
package height is useful for defining a package ordering.
Updates #24693.
Change-Id: I965162c440b6c5397db91b621ea0be7fa63881f1
Reviewed-on: https://go-review.googlesource.com/105038
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Previously, constant pointer-typed expressions could use either Mpint
or NilVal as their Val depending on their construction, but const.go
expects each type to have a single corresponding Val kind.
This CL changes pointer-typed expressions to exclusively use Mpint.
Fixes#21221.
Change-Id: I6ba36c9b11eb19a68306f0b296acb11a8c254c41
Reviewed-on: https://go-review.googlesource.com/105315
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
This used to be duplicated in methcmp and siglt, because Sig used its
own representation for Syms. Instead, just use Syms, and add a
(*Sym).Less method that both methcmp and siglt can use.
Also, prune some impossible cases purportedly related to blank
methods: the Go spec disallows blank methods in interface method sets,
and addmethod drops blank methods without actually recording them in
the type's method set.
Passes toolstash-check.
Updates #24693.
Change-Id: I24e981659b68504d71518160486989a82505f513
Reviewed-on: https://go-review.googlesource.com/105936
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
When I added the text/template/parse lines, I thought that both removed
and added APIs should be listed here (i.e. both -pkg and +pkg lines).
However that was wrong, as one can see by reading cmd/api/goapi.go, or
seeing how removing the +pkg lines does not break the API test.
Change-Id: I0a8dcd6db44762dadb58728acfb844bf118c9d45
Reviewed-on: https://go-review.googlesource.com/105376
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Multi-byte comparison operations were used on amd64, arm64, i386
and s390x for comparisons with constant arrays, but only amd64 and
i386 for comparisons with string constants. This CL combines the
check for platform capability, since they have the same requirements,
and also enables both on ppc64le which also supports load merging.
Note that these optimizations currently use little endian byte order
which results in byte reversal instructions on s390x. This should
be fixed at some point.
Change-Id: Ie612d13359b50c77f4d7c6e73fea4a59fa11f322
Reviewed-on: https://go-review.googlesource.com/102558
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
If one is somewhat new to the command line or shell, it might be
surprising that changes applied to a file like $HOME/.profile will
seemingly not take effect, even if new shells are started.
Add a note about how shells usually only load these when the user logs
into a machine, to minimize the amount of people stuck and confused by
this.
Fixes#24756.
Change-Id: Ic68d8c97933f3f080b151a107633ecad76a163a4
Reviewed-on: https://go-review.googlesource.com/105557
Reviewed-by: Agniva De Sarker <agniva.quicksilver@gmail.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
