For example, the following program is valid:

	type T struct {
		f interface{}
	}

	func main() {
		fmt.Printf("%s", T{"foo"}) // prints {foo}
	}

Since the field is of type interface{}, we might have any value in it.
For example, if we had T{3}, fmt would complain. However, not knowing
what the type under the interface is, we must be conservative.

However, as shown in #17798, we should issue an error if the field's
type is statically known to implement the error or fmt.Stringer
interfaces. In those cases, the user likely wanted the %s format to call
those methods. Keep the vet error in those cases.

While at it, add more field type test cases, such as custom error types,
and interfaces that extend the error interface.

Fixes #23563.

Change-Id: I063885955555917c59da000391b603f0d6dce432
Reviewed-on: https://go-review.googlesource.com/90516
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

The current code encodes the wrong option value in the binary.

The fix reconstructs the function opxrrr() that does not encode the option
value into the binary value when arguments is sign or zero-extended register.

Add the relevant test cases and negative tests.

Fixes #23501
Change-Id: Ie5850ead2ad08d9a235a5664869aac5051762f1f
Reviewed-on: https://go-review.googlesource.com/88876
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Updates #23694

Change-Id: I5fdad8cceacb8bbc85ca2661eb6482aa80343656
Reviewed-on: https://go-review.googlesource.com/92075
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The speed of feature development for these products outpaces the
standard Go 6-month release cycle tied to this page. The cost of
maintaining this list is becoming a burden as we make every
attempt at being impartial. As of this writing, we believe feature
lists belong on the pages of the editors/IDEs themselves.

Change-Id: Ie2dfe0e0d47d203c913373e58cbb65cb0fb14d0c
Reviewed-on: https://go-review.googlesource.com/91976Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Otherwise we get into a dependency loop as we try to apply coverage
analysis to sync/atomic when the coverage analysis itself requires
sync/atomic.

Fixes #23694

Change-Id: I3a74ef3881ec5c6197ed348acc7f9e175417f6c7
Reviewed-on: https://go-review.googlesource.com/91875
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Was improperly bypassed in a couple places.

Change-Id: I13426b3efe68b9e67324c283540d0ef7b81b3d41
Reviewed-on: https://go-review.googlesource.com/91636
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

The old and exp packages listed in gccgoinstallation_test.go have been
removed from gccgo. Remove them from the test.

Fixes #20932

Change-Id: I04a5148e18dccef332904b836c42098b55f2516c
Reviewed-on: https://go-review.googlesource.com/91656
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The dlopen function returns an opaque handle, and it is possible for
it to look like a Go pointer, causing garbage collector and cgo
confusion.

Fixes #23663

Change-Id: Id080e2bbcee8cfa7ac4a457a927f96949eb913f8
Reviewed-on: https://go-review.googlesource.com/91596
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

The EBNF production

	Function = Signature FunctionBody .

was used in FunctionDecl, MethodDecl, and FunctionLit, but only
for the latter it shortened the syntax slightly.

This change "inlines" Function which simplifies FunctionDecl and
MethodDecl and gets rid of the Function production.

This has no impact on the specified language. Also, the Function
production is never referred to by the prose, so it's safe to
remove it from the spec.

Finally, neither go/ast nor go/parser have a representation of
this production via a corresponding node or parse function, so
no possibly valuable documentation is lost, either.

Change-Id: Ia2875d31c6ec2d2079081ef481e50bad4f43c694
Reviewed-on: https://go-review.googlesource.com/91515Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

Fixes #23653.

Change-Id: Ic1e3c8f156ae576cfb5da1b4d082d4b12fae114f
Reviewed-on: https://go-review.googlesource.com/91317
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

CL 91097 added TestNoCache. However, this
test is failing on Plan 9 because the HOME
environment variable doesn't contain the
home directory where the Go cache is located.

This change fixes the TestNoCache test
by using the home environment variable
instead of HOME on Plan 9.

Fixes #23644.

Change-Id: Icfb7a7a4c2852f159c93032b4081411628a2787f
Reviewed-on: https://go-review.googlesource.com/91216
Run-TryBot: David du Colombier <0intro@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

preparePanic must set all registers expected by Go runtime conventions
in case the sigpanic is being injected into C code. However, on
mips64x it fails to restore RSB (R28). As a result, if C code modifies
RSB and then raises a signal that turns into a sigpanic call, sigpanic
may crash when it attempts to lock runtime.debuglock (the first global
it references).

Fix this by restoring RSB in the signal context using the same
convention as main and sigtramp.

Fixes #23641.

Change-Id: Ib47e83df89e2a3eece10f480e4e91ce9e4424388
Reviewed-on: https://go-review.googlesource.com/91156
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Currently, gentraceback suppresses the "unexpected return pc" error
for sigpanic's caller if the M was running C code.

However, there are various situations where a sigpanic is injected
into C code that can cause traceback to unwind *past* the sigpanic
before realizing that it's in trouble (the traceback beyond the
sigpanic will be wrong).

Rather than try to fix these issues for Go 1.10, this CL simply
disables complaining about unexpected return PCs if we're in cgo
regardless of whether or not they're from the sigpanic frame. Go 1.9
never complained about unexpected return PCs when printing, so this is
simply a step closer to the old behavior.

This should fix the openbsd-386 failures on the dashboard, though this
issue could affect any architecture.

Fixes #23640.

Change-Id: I8c32c1ee86a70d2f280661ed1f8caf82549e324b
Reviewed-on: https://go-review.googlesource.com/91136
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

The getdents64 syscall is only available for mips64/mips64le starting
with Linux kernel 3.10. Since mips64le requires at least 4.8 according
to [1] (regarding #16848) using it should be fine.

[1] https://golang.org/wiki/MinimumRequirements

This CL changes the binary layout of type Dirent for mips64/mips64le,
but not the public API. But since the currently used layout doesn't
match the struct linux_dirent returned by the getdents syscall this
should be fine as well.

Fixes #23624

Change-Id: Iaa7306fa6e4442ad2fed41c60b37627a7314f117
Reviewed-on: https://go-review.googlesource.com/91055Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

The fix is CL 91035.

Build only with gccgo at the moment, as it hits issue #23546.

Updates #23545.

Change-Id: I3a1367bb31b04773d31f71016f8fd7bd1855d7b5
Reviewed-on: https://go-review.googlesource.com/89735
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #23638

Change-Id: I51967290448217f371fc7aba9259918ee9857143
Reviewed-on: https://go-review.googlesource.com/91097
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

If we're running C code and the code panics, the runtime will inject a
call to sigpanic into the C code just like it would into Go code.
However, the return PC from this sigpanic will be in C code. We used
to silently abort the traceback if we didn't recognize a return PC, so
this went by quietly. Now we're much louder because in general this is
a bad thing. However, in this one particular case, it's fine, so if
we're in cgo and are looking at the return PC of sigpanic, silence the
debug output.

Fixes #23576.

Change-Id: I03d0c14d4e4d25b29b1f5804f5e9ccc4f742f876
Reviewed-on: https://go-review.googlesource.com/90896
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

asmcgocall switches to the system stack and aligns the SP, so
gentraceback both can't unwind over it when it appears on the system
stack (it'll read some uninitialized stack slot as the return PC).
There's also no point in unwinding over it, so don't.

Updates #23576.

Change-Id: Idfcc9599c7636b80dec5451cb65ae892b4611981
Reviewed-on: https://go-review.googlesource.com/90895
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This happens in a chroot and so causes failures when packaging Go 1.10 for
Debian/Ubuntu.

Change-Id: I817038c237e584ce185b2168f8c7a10b9ef27b43
Reviewed-on: https://go-review.googlesource.com/90875
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Upstream PRs: https://github.com/google/pprof/pull/305,
https://github.com/google/pprof/pull/306.

Change-Id: I28969118f52ee08fcaf3572ad5da015ae756fd7a
Reviewed-on: https://go-review.googlesource.com/90935
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Also close </li> tags.

Fixes #23614

Change-Id: Icabcd577ef7df43e54d2b0068ee54614ba65bea1
Reviewed-on: https://go-review.googlesource.com/90815Reviewed-by: Cherry Zhang <cherryyz@google.com>

Executing

$ go tool dist test -run=^go_test:cmd/fix$

leaves a number of directories (fix_cgo_typecheck*) in TMPDIR.

Change-Id: Ia5bdc2f7d884333771d50365063faf514ebf6eae
Reviewed-on: https://go-review.googlesource.com/90795
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Updates #22912
Fixes #23610

Change-Id: Id1c91fc3f040412d5931dba40e430685793f8eea
Reviewed-on: https://go-review.googlesource.com/90715
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

For example, the following program is valid:

	func main() {
		fmt.Printf("%[1]d", 1, 2, 3)
	}

If any of the formats are indexed, fmt will not complain about unused
extra arguments. See #22867 for more detail.

Make vet follow the same logic, to avoid erroring on programs that would
run without fmt complaining.

Fixes #23564.

Change-Id: Ic9dede5d4c37d1cd4fa24714216944897b5bb7cc
Reviewed-on: https://go-review.googlesource.com/90495
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

vet was quiet for []stringer, but not for [N]stringer. The source of the
problem was how the recursive call used .Elem().Underlying() for arrays,
but .Elem() for slices. In the first case, the named type is dropped,
thus losing all information of attached methods.

Be consistent across slices and arrays, by dropping the Underlying call
that is causing trouble. Add regression tests too, including cases where
the element type does not implement fmt.Stringer.

Fixes #23552.

Change-Id: I0fde07d101f112d5768be0a79207ef0b3dc45f2e
Reviewed-on: https://go-review.googlesource.com/90455
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

vet recorded what types had String methods defined on them, but it did
not record whether the receivers were pointer types. That information is
important, as the following program is valid:

	type T string

	func (t *T) String() string {
		return fmt.Sprint(&t) // prints address
	}

Teach vet that, if *T is Stringer, **T is not.

Fixes #23550.

Change-Id: I1062e60e6d82e789af9cca396546db6bfc3541e8
Reviewed-on: https://go-review.googlesource.com/90417
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

The problem is that vet complains about 0 as a Printf flag in some
situations where fmt allows it but probably shouldn't. The two
need to be brought in line, but it's too late in the release cycle.

The situation is messy and should be resolved properly in 1.11. This
CL is a simple fix to disable a spurious complaint for 1.10 that will be
resolved in a more thorough way in 1.11.

The workaround is just to be silent about flag 0, as suggested in
issue 23605.

Fixes #23605
Update #23498

Change-Id: Ice1a4f4d86845d70c1340a0a6430d74e5de9afd4
Reviewed-on: https://go-review.googlesource.com/90695
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I802bc11d90d414e7313dd11842a04fd6b591ea06
Reviewed-on: https://go-review.googlesource.com/90595Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: If928b14f6cd89b1d78745e8bc7a081ccbd7fd38f
Reviewed-on: https://go-review.googlesource.com/90515Reviewed-by: Ian Lance Taylor <iant@golang.org>

CL 13166, CL 13342 and CL 33425 skipped external tests
on freebsd/arm, linux/arm and linux/mips.

This CL does the same for plan9/arm to reduce test time
on plan9/arm and prevent the Go builder to time out.

Change-Id: I16fcc5d8010a354f480673b8c4a8a11dbc833557
Reviewed-on: https://go-review.googlesource.com/90416
Run-TryBot: David du Colombier <0intro@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I7bf1a93d3377acccdd3a34c5dcef7863310496e0
Reviewed-on: https://go-review.googlesource.com/89955Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #23570.

Change-Id: I462ada2960d710c2c94dc22a59d292703d83f612
Reviewed-on: https://go-review.googlesource.com/90255Reviewed-by: Russ Cox <rsc@golang.org>

recover determines whether it's being called by a deferred frame by
matching its caller's argument frame pointer with the one recorded in
the panic object. That means its caller needs a valid and unique
argument frame pointer, so it must not be inlined.

With this fix, test/recover.go passes with -l=4.

Fixes #23557.

Change-Id: I1f32a624c49e387cfc67893a0829bb248d69c3d4
Reviewed-on: https://go-review.googlesource.com/90035
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Previously we allowed drivers to modify the row buffer used to scan
values when closing Rows. This is no longer acceptable and can lead
to data races.

Fixes #23519

Change-Id: I91820a6266ffe52f95f40bb47307d375727715af
Reviewed-on: https://go-review.googlesource.com/89936
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: Id2332332ba5ff5a3ae6e58882743aa25359c02f6
Reviewed-on: https://go-review.googlesource.com/89675Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Provide a fresh conversion table for TestConversions as it gets
modified on each test.

Change-Id: I6e2240d0c3455451271a6879e994b82222c3d44c
Reviewed-on: https://go-review.googlesource.com/89595
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

In Plan 9, each OS thread has its own independent working directory,
so the Go runtime for Plan 9 needs to coordinate Chdir and Getwd
operations to keep the working directory consistent for all goroutines.

The function os.Getwd in Plan 9 should always call syscall.Getwd
to retrieve the common working directory.  Failure to do this was
the cause of (at least some of) the intermittent failures in the
Plan 9 builders with a seemingly spurious "file does not exist"
message, when a thread's working directory had been removed in
another thread.

Change-Id: Ifb834ad025ee39578234ad3b04d08bc98e939291
Reviewed-on: https://go-review.googlesource.com/89575Reviewed-by: David du Colombier <0intro@gmail.com>
Run-TryBot: David du Colombier <0intro@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

If you use -coverpkg=all you get coverage for all packages in the build.
Go 1.9 used a global counter for all the GoCover variables, so that they
were distinct for the entire build. The global counter caused problems
with caching, so we switched to a per-package counter. But now the
GoCover_0 in one package may be dot-imported into another and
conflict with the GoCover_0 in that other package.

Reestablish (overwhelmingly likely) global uniqueness of GoCover
variables by appending an _xxxxxxxxxxxx suffix, where the x's are
the prefix of the SHA256 hash of the import path. The point is only
to avoid accidents, not to defeat people determined to break the tools.

Fixes #23432.

Change-Id: I3088eceebbe35174f2eefe8d558b7c8b59d3eeac
Reviewed-on: https://go-review.googlesource.com/89135Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: If8609dd7c4bdc261056804759ec254f8af0156df
Reviewed-on: https://go-review.googlesource.com/89417Reviewed-by: Ian Lance Taylor <iant@golang.org>

pprof expects the samples are scaled and reflects unsampled numbers.
The legacy profile parser uses the sampling period in the output
and multiplies all values with the period.

https://github.com/google/pprof/blob/0138a3cd6dad6f94495ba0b5c3a5c124f04ae011/profile/legacy_profile.go#L815

Apply the same scaling when we output the mutex profile
in the pprof proto format.

Block profile shares the same code, but how to infer unsampled
values is unclear. Legacy profile parser doesn't do anything special
so we do nothing for block profile here.

Tested by checking the profiles reported with debug=0 (proto format)
are similar to the profiles computed from legacy format profile
when the profile rate is a non-trivial number (e.g. 2) manually.

Change-Id: Iaa33f92051deed67d8be43ddffc7c1016db566ca
Reviewed-on: https://go-review.googlesource.com/89295Reviewed-by: Peter Weinberger <pjw@google.com>