The android emulator builders is running out of space after CL 165797
copied most of GOROOT to the device.
The pkg directory is by far the largest, so only include what seems
necessary to build the x/ repositories: pkg/android_$GOARCH and
pkg/tool/android_$GOARCH.
While here, rename the device root directory to match the exec
wrapper name and make sure the deferred cleanups actually run before
os.Exit.
Hopefully fixes the emulator builders.
Updates #23824
Change-Id: I4d1e3ab2c89fd1e5818503d323ddb87f073094da
Reviewed-on: https://go-review.googlesource.com/c/go/+/166397
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This also updates the vendored-in versions of several packages: 'go
mod vendor' selects a consistent version of each module, but we had
previously vendored an ad-hoc selection of packages.
Notably, x/crypto/hkdf was previously vendored in at a much newer
commit than the rest of x/crypto. Bringing the rest of x/crypto up to
that commit introduced an import of golang.org/x/sys/cpu, which broke
the js/wasm build, requiring an upgrade of x/sys to pick up CL 165749.
Updates #30228
Updates #30241
Updates #25822
Change-Id: I5b3dbc232b7e6a048a158cbd8d36137af1efb711
Reviewed-on: https://go-review.googlesource.com/c/go/+/164623
Reviewed-by: Filippo Valsorda <filippo@golang.org>
This change preserves the maximum versions from cmd/vendor/vendor.json
where feasible, but bumps the versions of x/sys (for CL 162987) and
x/tools (for CL 162989 and CL 160837) so that 'go test all' passes in
module mode when run from a working directory in src/cmd.
A small change to cmd/vet (not vendored) was necessary to preserve its
flag behavior given a pristine copy of x/tools; see CL 162989 for more
detail.
This change was generated by running 'go mod vendor' at CL 164622.
(Welcoooome to the fuuuuuture!)
Updates #30228
Updates #30241
Change-Id: I889590318dc857d4a6e20c3023d09a27128d8255
Reviewed-on: https://go-review.googlesource.com/c/go/+/164618
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Two tests (load_le_byte8_uint64_inv and load_be_byte8_uint64)
pass but the generated code isn't actually correct.
The test regexp provides a false negative, as it matches the
MOVQ (SP), BP instruction in the epilogue.
Combined loads never worked for these cases - the test was added in error
as part of a batch and not noticed because of the above false match.
Normalize the amd64/386 tests to always negative match on narrower
loads and OR.
Change-Id: I256861924774d39db0e65723866c81df5ab5076f
Reviewed-on: https://go-review.googlesource.com/c/go/+/166837
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
os.Pipe is not implemented on wasm/js so for that purpose use
a temporary file for js/wasm. This change creates two versions
of runExample:
* runExample verbatim that still uses os.Pipe for non js/wasm
* runExample that uses a temporary file
Also added a TODO to re-unify these function versions back into
example.go wasm/js gets an os.Pipe implementation.
Change-Id: I9f418a49b2c397e1667724c7442b7bbe8942225e
Reviewed-on: https://go-review.googlesource.com/c/go/+/165357
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
I want to be able to write
MOV(Q|Q|L|L|L|W|W|B)loadidx(1|8|1|4|8|1|2|1)
instead of
MOV(Qloadidx1|Qloadidx8|Lloadidx1|Lloadidx4|Lloadidx8|Wloadidx1|Wloadidx2|Bloadidx1)
in rewrite rules.
Both are fairly cryptic and hard to review, but the former
is at least compact, which helps to not obscure the structure
of the rest of the rule.
Support that by adjusting rulegen's expansion.
Instead of looking for an op that begins with "(", ends with " ",
and has exactly one set of parens in it, look for everything of the
form "(...|...)".
That has false positives: Go code in the && conditions and AuxInt expressions.
Those are easily checked for syntactically: && conditions are between && and ->,
and AuxInt expressions are inside square brackets.
After ruling out those false positives, we can keep everything else,
regardless of where it is.
No change to the generated code for existing rules.
Change-Id: I5b70a190e268989504f53cb2cce2f9a50170d8a2
Reviewed-on: https://go-review.googlesource.com/c/go/+/166737
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Refactoring only.
This makes it easier to add ops
that do indexed memory loads/stores.
Passes toolstash-check.
Change-Id: I82df0d4154718577ec42106fa1bc76571bf65096
Reviewed-on: https://go-review.googlesource.com/c/go/+/166425
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
If you write a rewrite rule:
(something) && noteRule("X")-> (something)
then rulegen will panic with an error message about commutativity.
The real problem is the lack of a space between the ) and the ->.
Normalize that bit of whitespace too.
Change-Id: Idbd53687cd0398fe275ff2702667688cad05b4ca
Reviewed-on: https://go-review.googlesource.com/c/go/+/166427
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The unprivileged_userns_clone sysctl prevents unpriviledged users from
creating namespaces, which the AmbientCaps test does. It's set to 0 by
default in a few Linux distributions (Debian and Arch, possibly
others), so we need to check it before running the test.
I've verified that setting
echo 1 > /proc/sys/kernel/unprivileged_userns_clone
and then running the test *without this patch* makes it pass, which
proves that checking unprivileged_userns_clone is indeed sufficient.
Fixes#30698
Change-Id: Ib2079b5e714d7f2440ddf979c3e7cfda9a9c5005
Reviewed-on: https://go-review.googlesource.com/c/go/+/166460
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
There are no empty function declarations in package strings anymore, so
strings.s is no longer needed.
Change-Id: I16fe161a9c06804811e98af0ca074f8f46e2f49d
Reviewed-on: https://go-review.googlesource.com/c/go/+/166458
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
While many other call sites have been moved to using the proper
higher-level system loading, these areas were left out. This prevents
DLL directory injection attacks. This includes both the runtime load
calls (using LoadLibrary prior) and the implicitly linked ones via
cgo_import_dynamic, which we move to our LoadLibraryEx. The goal is to
only loosely load kernel32.dll and strictly load all others.
Meanwhile we make sure that we never fallback to insecure loading on
older or unpatched systems.
This is CVE-2019-9634.
Fixes#14959Fixes#28978Fixes#30642
Change-Id: I401a13ed8db248ab1bb5039bf2d31915cac72b93
Reviewed-on: https://go-review.googlesource.com/c/go/+/165798
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
In the normal case, only a few words have to be updated when adding a word to a vector.
When that happens, we can simply copy the rest of the words, which is much faster.
However, the overhead of that makes it prohibitive for small vectors,
so we check the size at the beginning.
The implementation is a bit weird to allow addVW to continued to be inlined; see #30548.
The AddVW benchmarks are surprising, but fully repeatable.
The SubVW benchmarks are more or less as expected.
I expect that removing the indirect function call will
help both and make them a bit more normal.
name old time/op new time/op delta
AddVW/1-8 4.27ns ± 2% 3.81ns ± 3% -10.83% (p=0.000 n=89+90)
AddVW/2-8 4.91ns ± 2% 4.34ns ± 1% -11.60% (p=0.000 n=83+90)
AddVW/3-8 5.77ns ± 4% 5.76ns ± 2% ~ (p=0.365 n=91+87)
AddVW/4-8 6.03ns ± 1% 6.03ns ± 1% ~ (p=0.392 n=80+76)
AddVW/5-8 6.48ns ± 2% 6.63ns ± 1% +2.27% (p=0.000 n=76+74)
AddVW/10-8 9.56ns ± 2% 9.56ns ± 1% -0.02% (p=0.002 n=69+76)
AddVW/100-8 90.6ns ± 0% 18.1ns ± 4% -79.99% (p=0.000 n=72+94)
AddVW/1000-8 865ns ± 0% 85ns ± 6% -90.14% (p=0.000 n=66+96)
AddVW/10000-8 8.57µs ± 2% 1.82µs ± 3% -78.73% (p=0.000 n=99+94)
AddVW/100000-8 84.4µs ± 2% 31.8µs ± 4% -62.29% (p=0.000 n=93+98)
name old time/op new time/op delta
SubVW/1-8 3.90ns ± 2% 4.13ns ± 4% +6.02% (p=0.000 n=92+95)
SubVW/2-8 4.15ns ± 1% 5.20ns ± 1% +25.22% (p=0.000 n=83+85)
SubVW/3-8 5.50ns ± 2% 6.22ns ± 6% +13.21% (p=0.000 n=91+97)
SubVW/4-8 5.99ns ± 1% 6.63ns ± 1% +10.63% (p=0.000 n=79+61)
SubVW/5-8 6.75ns ± 4% 6.88ns ± 2% +1.82% (p=0.000 n=98+73)
SubVW/10-8 9.57ns ± 1% 9.56ns ± 1% -0.13% (p=0.000 n=77+64)
SubVW/100-8 90.3ns ± 1% 18.1ns ± 2% -80.00% (p=0.000 n=75+94)
SubVW/1000-8 860ns ± 4% 85ns ± 7% -90.14% (p=0.000 n=97+99)
SubVW/10000-8 8.51µs ± 3% 1.77µs ± 6% -79.21% (p=0.000 n=100+97)
SubVW/100000-8 84.4µs ± 3% 31.5µs ± 3% -62.66% (p=0.000 n=92+92)
Change-Id: I721d7031d40f245b4a284f5bdd93e7bb85e7e937
Reviewed-on: https://go-review.googlesource.com/c/go/+/164968
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
mustBe was barely over budget, so manually inlining the first flag.kind
call is enough. Add a TODO to reverse that in the future, once the
compiler gets better.
mustBeExported and mustBeAssignable were over budget by a larger amount,
so add slow path functions instead. This is the same strategy used in
the sync package for common methods like Once.Do, for example.
Lots of exported reflect.Value methods call these assert-like unexported
methods, so avoiding the function call overhead in the common case does
shave off a percent from most exported APIs.
Finally, add the methods to TestIntendedInlining.
While at it, replace a couple of uses of the 0 Kind with its descriptive
name, Invalid.
name old time/op new time/op delta
Call-8 68.0ns ± 1% 66.8ns ± 1% -1.81% (p=0.000 n=10+9)
PtrTo-8 8.00ns ± 2% 7.83ns ± 0% -2.19% (p=0.000 n=10+9)
Updates #7818.
Change-Id: Ic1603b640519393f6b50dd91ec3767753eb9e761
Reviewed-on: https://go-review.googlesource.com/c/go/+/166462
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Value.CanInterface and Value.pointer are now inlinable, since we have a
limited form of mid-stack inlining. Their calls to panic were preventing
that in previous Go releases. The other three methods still go over
budget, so update that comment.
In recent commits, sync.Once.Do and multiple lock/unlock methods have
also been made inlinable, so add those as well. They have standalone
tests like test/inline_sync.go already, but it's best if the funcs are
in this global test table too. They aren't inlinable on every platform
yet, though.
Finally, use math/bits.UintSize to check if GOARCH is 64-bit, now that
we can.
Change-Id: I65cc681b77015f7746dba3126637e236dcd494e0
Reviewed-on: https://go-review.googlesource.com/c/go/+/166461
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Using Once.Do is now extremely cheap because the fast path is just an inlined
atomic load of a variable that is written only once and a conditional jump.
This is very beneficial for Once.Do because, due to its nature, the fast path
will be used for every call after the first one.
In a attempt to mimize code size increase, reorder the fields so that the
pointer to Once is also the pointer to Once.done, that is the only field used
in the hot path. This allows to use more compact instruction encodings or less
instructions in the hot path (that is inlined at every callsite).
name old time/op new time/op delta
Once 4.54ns ± 0% 2.06ns ± 0% -54.59% (p=0.000 n=19+16)
Once-4 1.18ns ± 0% 0.55ns ± 0% -53.39% (p=0.000 n=15+16)
Once-16 0.53ns ± 0% 0.17ns ± 0% -67.92% (p=0.000 n=18+17)
linux/amd64 bin/go 14675861 (previous commit 14663387, +12474/+0.09%)
Change-Id: Ie2708103ab473787875d66746d2f20f1d90a6916
Reviewed-on: https://go-review.googlesource.com/c/go/+/152697
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Turns out this makes the fix for 28797 unnecessary, because this order
ensures that the RHS of IsSliceInBounds ops are always nonnegative.
The real reason for this change is that it also makes dealing with
<0 values easier for reporting values in bounds check panics (issue #30116).
Makes cmd/go negligibly smaller.
Update #28797
Change-Id: I1f25ba6d2b3b3d4a72df3105828aa0a4b629ce85
Reviewed-on: https://go-review.googlesource.com/c/go/+/166377
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
In order to allow DWARF with ld, the symbol table is adapted.
In internal linkmode, each package is considered as a .FILE. However,
current version of ld is crashing on a few programs because of
relocations between DWARF symbols. Considering all packages as part of
one .FILE seems to bypass this bug.
As it might be fixed in a future release, the size of each package
in DWARF sections is still retrieved and can be used when it's fixed.
Moreover, it's improving internal linkmode which should have done it
anyway.
Change-Id: If3d023fe118b24b9f0f46d201a4849eee8d5e333
Reviewed-on: https://go-review.googlesource.com/c/go/+/164006
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Symbol name with linker prefix like "type." and "go." is not parsed
correctly and returns the prefix as parts of package name.
So just returns empty string for symbol name start with linker prefix.
Fixes#29551
Change-Id: Idb4ce872345e5781a5a5da2b2146faeeebd9e63b
Reviewed-on: https://go-review.googlesource.com/c/go/+/156397
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
When 'go mod init' is run without a module path, it tries to infer a
module path, based on the current directory (if in GOPATH), import
comments, and vendor configuration files.
It's common for this command to fail the first time a user tries to
create a module in a new project outside GOPATH. This change improves
the wording of the error message to hint that the user should specify
a module path.
Fixes#30678
Change-Id: Iec0352e919dbc8b426ab71eed236fad3929ec671
Reviewed-on: https://go-review.googlesource.com/c/go/+/166319
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
It turns out not to be necessary. Russ expressed a preference for
avoiding module fetches over making 'go mod tidy' work within std and
cmd right away, so for now we will make the loader use the vendor
directory for the standard library even if '-mod=vendor' is not set
explicitly.
Updates #30228
Change-Id: Idf7208e63da8cb7bfe281b93ec21b61d40334947
Reviewed-on: https://go-review.googlesource.com/c/go/+/166357
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Android tests are built on the host and run on the device. To do
that, the exec wrapper copies the test binary and testdata to the device.
To enable many more tests, make the copied environment more like the host:
- Copy all of pkg from GOROOT, not just the android pkg directory.
- Copy any parent testdata directories as well as the package's own.
- Copy *.go files from the package directory. This enables misc/cgo/stdio
and misc/cgo/life tests that were invisible before so disable them explicitly.
- Always copy the GOROOT, even for tests outside GOROOT. This is expensive
but only done once per make.bash.
- Build the go tool for the device and put it in PATH. Set GOCACHE
to a writable directory and disable cgo.
While here, use a single directory for all the exec wrapper files and
delete that once per make.bash as well.
In total, this CL enables many tests in the subrepos that would need skips
without it, in particular the x/tools tests.
Fixes#11452
Updates #23824
Updates #11811
Change-Id: I2e50d8b57db9bc4637f25272a5360c8b2cf4e627
Reviewed-on: https://go-review.googlesource.com/c/go/+/165797
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Currently they aren't marked as deprecated as Godoc, but the comments
mention that they are deprecated. Mark them as officially deprecated.
Fixes#29576
Change-Id: I795c698ac715476023d80579d60932fba4c5edde
Reviewed-on: https://go-review.googlesource.com/c/go/+/156331
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Args were duplicated by a mistake. Found using static analysis tools.
Change-Id: I2f61e09844bc409b1f687d654767332d93dd39a2
Reviewed-on: https://go-review.googlesource.com/c/go/+/164937
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Change-Id: I6638cb0f9ed751c76a29cae62a93a923f18f14f3
Reviewed-on: https://go-review.googlesource.com/c/go/+/164005
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
According to the prctl man page, each capability from the ambient set
must already be present in both the permitted and the inheritable
sets of the process.
exec_linux_test suggests configuring the capabilities in the parent
process. This doesn't look nice, because:
* Capabilities are a per-thread attribute, so we need to use
LockOSThread.
* Need to restore capabilities after creating a process.
* Doesn't work with user namespaces, because a process gets capabilities
when a namespace is created.
Fixes#23152
Change-Id: Iba23e530fc7b9f5182d602fe855f82218f354219
Reviewed-on: https://go-review.googlesource.com/c/go/+/156577
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
"go list -test" constructs a package graph, then creates test packages
for the target. If it encounters an error (for example, a syntax error
in a test file or a test function with the wrong signature), it
reports the error and exits without printing the test packages or
their dependencies, even if the -e flag is given. This is a problem
for tools that operate on test files while users are editing them. For
example, autocomplete may not work while the user is typing.
With this change, a new function, load.TestPackagesAndErrors replaces
TestPackagesFor. The new function attaches errors to the returned test
packages instead of returning immediately. "go list -test" calls this
when the -e flag is set. TestPackagesFor now returns the same error as
before, but it returns non-nil packages so that "go list -test"
without -e can print partial results.
Fixes#28491
Change-Id: I141765c4574eae424d872eb9bf7dd63fdfb85efb
Reviewed-on: https://go-review.googlesource.com/c/go/+/164357
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
If srcDir is within GOROOT, prefer GOROOT.
Otherwise, prefer GOPATH.
The attached tests may seem a bit strange; they will make more sense
in a followup CL.
Updates #16333
Updates #30241
Updates #30228
Change-Id: Ic5f1334cce5e242d7f49080aba083bcf2080dee3
Reviewed-on: https://go-review.googlesource.com/c/go/+/164619
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
The -coverpkg lets users specify a list of packages that should have
coverage instrumentation. This may include packages not transitively
imported by tests. For each tested package, the synthetic main package
imports all covered packages so they can be registered with
testing.RegisterCover. This makes it possible for a main package to
import another main package.
When we compile a package with p.Internal.BuildInfo set (set on main
packages by Package.load in module mode), we set
runtime/debug.modinfo. Multiple main packages may be passed to the
linker because of the above scenario, so this causes duplicate symbol
errors.
This change copies p.Internal.BuildInfo to the synthetic main package
instead of the internal test package. Additionally, it forces main
packages imported by the synthetic test main package to be recompiled
for testing. Recompiled packages won't have p.Internal.BuildInfo set.
Fixes#30374
Change-Id: I06f028d55905039907940ec89d2835f5a1040203
Reviewed-on: https://go-review.googlesource.com/c/go/+/164877
Run-TryBot: Jay Conrod <jayconrod@google.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
With standard-library modules and vendoring, the mapping from import
path to directory within the standard library is no longer entirely
trivial. Fortunately, 'go list' makes that mapping straightforward to
compute.
Updates #30241
Updates #30228
Change-Id: Iddd77c21a527b7acdb30c17bec8b4bbd43e23756
Reviewed-on: https://go-review.googlesource.com/c/go/+/165497
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
If a for loop has a simple condition and begins with a simple
"if x { break; }"; we can simply add "!x" to the loop's condition.
While at it, simplify a few assignments to use the common pattern
"x := staticDefault; if cond { x = otherValue(); }".
Finally, simplify a couple of var declarations.
Change-Id: I413982c6abd32905adc85a9a666cb3819139c19f
Reviewed-on: https://go-review.googlesource.com/c/go/+/165342
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The warnings are not strictly tied to FreeBSD but to the clang version.
People could still be building with an old version of clang even if not
on FreeBSD. The -Wpragmas and -Waddress-of-packed-member warnings were
introduced in clang 4.0, so also adjust the comment accordingly.
This was discussed as part of CL 160777 which introduced these comments.
Updates #27619
Change-Id: I4988ffd08797dcc72cdc264d4abd20a114f70473
Reviewed-on: https://go-review.googlesource.com/c/go/+/165800
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Yuval Pavel Zholkover <paulzhol@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
