Currently, startpanic_m (which prepares for an unrecoverable panic)
goes out of its way to make it possible to allocate during panic
handling by allocating an mcache if there isn't one.

However, this is both potentially dangerous and unnecessary.
Allocating an mcache is a generally complex thing to do in an already
precarious situation. Specifically, it requires obtaining the heap
lock, and there's evidence that this may be able to deadlock (#23360).
However, it's also unnecessary because we never allocate from the
unrecoverable panic path.

This didn't use to be the case. The call to allocmcache was introduced
long ago, in CL 7388043, where it was in preparation for separating Ms
and Ps and potentially running an M without an mcache. At the time,
after calling startpanic, the runtime could call String and Error
methods on panicked values, which could do anything including
allocating. That was generally unsafe even at the time, and CL 19792
fixed this be pre-printing panic messages before calling startpanic.
As a result, we now no longer allocate after calling startpanic.

This CL not only removes the allocmcache call, but goes a step further
to explicitly disallow any allocation during unrecoverable panic
handling, even in situations where it might be safe. This way, if
panic handling ever does an allocation that would be unsafe in unusual
circumstances, we'll know even if it happens during normal
circumstances.

This would help with debugging #23360, since the deadlock in
allocmcache is currently masking the real failure.

Beyond all.bash, I manually tested this change by adding panics at
various points in early runtime init, signal handling, and the
scheduler to check unusual panic situations.

Change-Id: I85df21e2b4b20c6faf1f13fae266c9339eebc061
Reviewed-on: https://go-review.googlesource.com/88835
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Currently, if a _SigPanic signal arrives in a throwsplit context,
nothing is stopping the runtime from injecting a call to sigpanic that
may attempt to grow the stack. This will fail and, in turn, mask the
real problem.

Fix this by checking for throwsplit in the signal handler itself
before injecting the sigpanic call.

Updates #21431, where this problem is likely masking the real problem.

Change-Id: I64b61ff08e8c4d6f6c0fb01315d7d5e66bf1d3e2
Reviewed-on: https://go-review.googlesource.com/87595
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

When we introduced the notion of alias type declarations, we renamed
"named type" to "defined type" to avoid confusion with types denoted
by aliases and thus are also types with names, or "named types".

Some of the old uses of "named types" remained; this change removes
them.

Now the spec consistently uses the terms:

- "defined type"  for a type declared via a type definition
- "type name"     for any name denoting an (alias or defined) type
- "alias"         for a type name declared in an alias declaration

New prose is encouraged to avoid the term "named type" to counter-
act further confusion.

Fixes #23474.

Change-Id: I5fb59f1208baf958da79cf51ed3eb1411cd18e03
Reviewed-on: https://go-review.googlesource.com/89115Reviewed-by: Rob Pike <r@golang.org>

The current code misassembles VLD1/VST1 instruction with non-zero
offset. The offset is dropped silently without any error message.
The cause of the misassembling is the current code treats argument
(Rn)(Rm) as ZOREG type.

The fix changes the matching rules and considers (Rn)(Rm) as ROFF
type. The fix will report error information when assembles VLD1/VST1
(R8)(R13), [V1.16B].
The fix enables the ARM64Errors test.

Fixes #23448

Change-Id: I3dd518b91e9960131ffb8efcb685cb8df84b70eb
Reviewed-on: https://go-review.googlesource.com/87956Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Except for removing the DRAFT marker, I think these are now ready to go.

Change-Id: I20604f5b135616189a24990db463c7bb5e7d48f1
Reviewed-on: https://go-review.googlesource.com/88975
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This error is returned by os.Mkdir when the directory already exists.

This change fixes some upspin tests.

Change-Id: I9ad5aefebb32dff577726d537b4f3826d79868eb
Reviewed-on: https://go-review.googlesource.com/88656Reviewed-by: David du Colombier <0intro@gmail.com>
Run-TryBot: David du Colombier <0intro@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

When there is no go directory inside the swiglib directory then swig
was installed without Go support. Tests in misc/swig will fail when
swig is installed without Go support.

Add additional checks for the presence of a go directory in the directory
reported by 'swig -go -swiglib' to determine if misc/swig tests should
be run.

This avoids all.bash failing when swig but not swig-go is installed
using macports.

Tested on darwin with swig and with and without swig-go installed
using macports.

Fixes #23469

Change-Id: I173201221554982ea0d9f2bea70a3cb85b297cec
Reviewed-on: https://go-review.googlesource.com/88776Reviewed-by: David Chase <drchase@google.com>

Update golang/go#23515

Change-Id: Id334d8663bf4cbb68f224d1bba4c9ad3855f8aae
Reviewed-on: https://go-review.googlesource.com/89155Reviewed-by: Andrew Gerrand <adg@golang.org>

In earlier versions of Go the "go vet" command would run on regular
source files and test files. That was lost in CL74750.  Bring it back.

This required moving a chunk of code from internal/test to
internal/load. The diff looks big but the code is unchanged.

Fixes #23395

Change-Id: Ie9ec183337e8db81c5fc421d118a22b351b5409e
Reviewed-on: https://go-review.googlesource.com/87636
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Currently, if anything goes wrong when printing a traceback, we simply
cut off the traceback without any further diagnostics. Unfortunately,
right now, we have a few issues that are difficult to debug because
the traceback simply cuts off (#21431, #23484).

This is an attempt to improve the debuggability of traceback failure
by printing a diagnostic message plus a hex dump around the failed
traceback frame when something goes wrong.

The failures look like:

goroutine 5 [running]:
runtime: unexpected return pc for main.badLR2 called from 0xbad
stack: frame={sp:0xc42004dfa8, fp:0xc42004dfc8} stack=[0xc42004d800,0xc42004e000)
000000c42004dea8:  0000000000000001  0000000000000001
000000c42004deb8:  000000c42004ded8  000000c42004ded8
000000c42004dec8:  0000000000427eea <runtime.dopanic+74>  000000c42004ded8
000000c42004ded8:  000000000044df70 <runtime.dopanic.func1+0>  000000c420001080
000000c42004dee8:  0000000000427b21 <runtime.gopanic+961>  000000c42004df08
000000c42004def8:  000000c42004df98  0000000000427b21 <runtime.gopanic+961>
000000c42004df08:  0000000000000000  0000000000000000
000000c42004df18:  0000000000000000  0000000000000000
000000c42004df28:  0000000000000000  0000000000000000
000000c42004df38:  0000000000000000  000000c420001080
000000c42004df48:  0000000000000000  0000000000000000
000000c42004df58:  0000000000000000  0000000000000000
000000c42004df68:  000000c4200010a0  0000000000000000
000000c42004df78:  00000000004c6400  00000000005031d0
000000c42004df88:  0000000000000000  0000000000000000
000000c42004df98:  000000c42004dfb8  00000000004ae7d9 <main.badLR2+73>
000000c42004dfa8: <00000000004c6400  00000000005031d0
000000c42004dfb8:  000000c42004dfd0 !0000000000000bad
000000c42004dfc8: >0000000000000000  0000000000000000
000000c42004dfd8:  0000000000451821 <runtime.goexit+1>  0000000000000000
000000c42004dfe8:  0000000000000000  0000000000000000
000000c42004dff8:  0000000000000000
main.badLR2(0x0)
	/go/src/runtime/testdata/testprog/badtraceback.go:42 +0x49

For #21431, #23484.

Change-Id: I8718fc76ced81adb0b4b0b4f2293f3219ca80786
Reviewed-on: https://go-review.googlesource.com/89016
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Change-Id: I689ccfb8452a170629425dc97da503b28766c6f9
Reviewed-on: https://go-review.googlesource.com/89035Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: Id71c1ccb584fb308f1615c0ed1255cc8b44bf675
Reviewed-on: https://go-review.googlesource.com/88256
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

On an android/amd64 emulator, $HOME points to / which is not writable.
Ignore the error in the pprof driver test.

With this, androidtest.sh on android/amd64 and android/386 passes.

Upstream pull request https://github.com/google/pprof/pull/295.

Change-Id: If919d7f44530a977fd044631ad01bac87d32deaa
Reviewed-on: https://go-review.googlesource.com/88817
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>

Change-Id: I14eeda85f279d1082ea9f2ac590b848ac13b1daa
Reviewed-on: https://go-review.googlesource.com/87023
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

Fix breakage introduced in CL 70530.

Change-Id: I87f3da6b20554d4f405a1143b0d894c5953b63aa
Reviewed-on: https://go-review.googlesource.com/88516
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>

Introduce GOANDROID_ADB_FLAGS for additional flags to adb invocations.
With GOANDROID_ADG_FLAGS, the Android builders can distinguish between
emulator and device builds.

Change-Id: I11729926a523ee27f6a3795cb2cfb64a9454f0a5
Reviewed-on: https://go-review.googlesource.com/88795
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>

When running locally, it will redirect properly to golang.org/dl/
(see https://github.com/golang/tools/blob/master/cmd/godoc/dl.go).

This is to support domains in prod other than golang.org.

Change-Id: I6d3051fcd7e06a86442324a64d781d8ad95c624f
Reviewed-on: https://go-review.googlesource.com/88679Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes #23480

Change-Id: I33b4bdc60b9983ab62d87bfa0ae3ff33304269c0
Reviewed-on: https://go-review.googlesource.com/88515Reviewed-by: Rob Pike <r@golang.org>

Change-Id: Ic7a5d3118754b34ab0652fcef889259a03baebc3
Reviewed-on: https://go-review.googlesource.com/88536Reviewed-by: Ian Lance Taylor <iant@golang.org>

When casting between *C.CFTypeRef and *unsafe.Pointer, we used to be
able to do the cast directly. Now with C.CFTypeRef being a uintptr
instead of an unsafe.Pointer, we need an intermediate cast.

Add the insertion of the intermediate cast to the cftype fix module.

Fixes #23091

Change-Id: I891be2f4a08cfd7de1cc4c6ab841b1e0d8c388a6
Reviewed-on: https://go-review.googlesource.com/88175Reviewed-by: Robert Griesemer <gri@golang.org>

This change expands the documentation for Verify to mention the name
constraints and EKU behaviour.

Change-Id: Ifc80faa6077c26fcc1d2a261ad1d14c00fd13b23
Reviewed-on: https://go-review.googlesource.com/87300Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This causes a performance regression for some calls.

Fixes #23424.
Updates #6853.

Change-Id: Id1db652d5aca0ce631a3417c0c056d6637fefa9e
Reviewed-on: https://go-review.googlesource.com/88135
Run-TryBot: Caleb Spare <cespare@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

cgo uses the presence of these functions to determine whether
a given type is in the CFTypeRef hierarchy and thus should be
a uintptr instead of a pointer. But if the *GetTypeID functions
aren't used by the user code, then they won't be present in the
cgo output, and thus cmd/fix won't see them.

Use the simpler rule that anything ending in *Ref should be
rewritten. This could over-rewrite, but I don't see a simpler
solution. Unlike cgo, it is easy to edit the output to fix any
issues. And fix is a much rarer operation than cgo.

This is a revert of portions of CL 87616.

Update #23091

Change-Id: I74ecd9fb25490a3d279b372e107248452bb62185
Reviewed-on: https://go-review.googlesource.com/88075
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

Fixes #23443.

Change-Id: If60c39b582ee5308e9fa902f93c1b6ae7890346c
Reviewed-on: https://go-review.googlesource.com/87975Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

If a file uses cgo, incorporate the types generated by running cgo.

Update #23091

Change-Id: I10958fa7fd6027c2c96a9fd8a9658de35439719f
Reviewed-on: https://go-review.googlesource.com/87616Reviewed-by: Robert Griesemer <gri@golang.org>

Cgo currently maps CFTypeRef and its subtypes to unsafe.Pointer
or a pointer to a named empty struct.

However, Darwin sometimes encodes some of CFTypeRef's subtypes as a
few int fields packed in a pointer wrapper. This hackery confuses the
Go runtime as the pointers can look like they point to things that
shouldn't be pointed at.

Switch CFTypeRef and its subtypes to map to uintptr.

Detecting the affected set of types is tricky, there are over 200 of
them, and the set isn't static across Darwin versions. Fortunately,
downcasting from CFTypeRef to a subtype requires calling CFGetTypeID,
getting a CFTypeID token, and comparing that with a known id from a
*GetTypeID() call. So we can find all the type names by detecting all
the *GetTypeID() prototypes and rewriting the corresponding *Ref types
to uintptr. This strategy covers all the cases I've checked and is
unlikely to have a false positive.

Update #23091.

Change-Id: I487eb4105c9b4785ba564de9c38d472c8c9a76ac
Reviewed-on: https://go-review.googlesource.com/87615
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

We used a mix of both before.

I've never heard anybody say "an arr-double you mutex" when speaking.

Fixes #23457

Change-Id: I802b5eb2339f885ca9d24607eeda565763165298
Reviewed-on: https://go-review.googlesource.com/87896Reviewed-by: Andrew Bonventre <andybons@golang.org>

CL 67332 created the fast no-syscall path for time.Now in High Sierra
but managed to break Sierra and older by forcing them into the slow
syscall path: the version check based on commpage version was wrong.

This CL uses the Darwin version number instead.

The assembly diff is noisy because many variables had to be
renamed, but the only actual change is the version check.

Fixes #23419.

Change-Id: Ie31ef5fb88f66d1517a8693942a7fb6100c213b0
Reviewed-on: https://go-review.googlesource.com/87655
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

The tool was moved to tools/Testing/selftests within the Linux kernel
source tree. Adjust the URL in the comments of vdso_linux.go

Change-Id: I86b9cae4b898c4a45bc7c54891ce6ead91a22670
Reviewed-on: https://go-review.googlesource.com/87815Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I248cb10a2e24f089600c13e86da251970c773d95
Reviewed-on: https://go-review.googlesource.com/87662Reviewed-by: Ian Lance Taylor <iant@golang.org>

The cgo checker was issuing an error with cgocheck=2 when a timer
bucket was stored in a pollDesc. The pollDesc values are allocated
using persistentalloc, so they are not in the Go heap. The code is OK
since timer bucket pointers point into a global array, and as such are
never garbage collected or moved.

Mark timersBucket notinheap to avoid the problem. timersBucket values
only occur in the global timers array.

Fixes #23435

Change-Id: I835f31caafd54cdacc692db5989de63bb49e7697
Reviewed-on: https://go-review.googlesource.com/87637
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

I found the previous text choppy and hard to follow, and in putting
this CL together, based entirely on the existing text, I found
several details that seemed misleading to me.

This is my attempt to make the text simultaneously easier to
understand, more complete, and more precise. I may have failed in
all three, but I wanted to try.

Change-Id: I088cb457f6fcad8f2b40236949cc3ac43455e600
Reviewed-on: https://go-review.googlesource.com/87735Reviewed-by: Russ Cox <rsc@golang.org>

Updates #19957

Change-Id: I8e2e3837db9e5e69b7102f9bd5831fe78ac60cfc
Reviewed-on: https://go-review.googlesource.com/87335
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

Fixes #23190

Change-Id: I96805aaab44ddaae6098b4e3af30f9e52585eae0
Reviewed-on: https://go-review.googlesource.com/87675
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

After CL 69831, addTransitiveLinkDeps ensures that all dependencies of
a link appear in Deps. We no longer need to traverse through all
actions to find them. And the old scheme of looking through all the
actions and assuming we would see shared library actions before
libraries they depend on no longer works.

Now that we have complete deps, change to a simpler scheme in which we
find the shared libraries in the deps, and then use that to sort the
deps into archives and shared libraries.

Fixes #22224

Change-Id: I14fcc773ac59b6f5c2965cc04d4ed962442cc89e
Reviewed-on: https://go-review.googlesource.com/87497
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Fixes #20708.

Change-Id: I2db450947b64b8b5af3822c7fbcc3e99746ae9d7
Reviewed-on: https://go-review.googlesource.com/87496Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Every few months we get a new error report claiming that there
is a typo in the spec related to this specific example. Clearly,
the fact that two types with the same identifier are identical
seems exceedingly obvious to readers; thus the example seems not
worth the trouble. Removing it.

For #9226.
For #22202.
For #22495.
For #23096.
For #23409.

There may be more.

Change-Id: I003ba79dc460ffb028a4ecb5f29efd60f2551912
Reviewed-on: https://go-review.googlesource.com/87417Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Change-Id: I085870d978a3a560588711882c77060d136d867a
Reviewed-on: https://go-review.googlesource.com/87415
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I8688a47ae83f6719f6134c64fb3d3f2aa275c641
Reviewed-on: https://go-review.googlesource.com/87158
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: I13afaa894292bd566510b40a5e4bbbe4d72d4d08
Reviewed-on: https://go-review.googlesource.com/87395Reviewed-by: Ian Lance Taylor <iant@golang.org>