delta/go-git.git/src, branch dev.unified

[dev.unified] all: merge master (85d87b9) into dev.unified

2022-08-04T17:12:28+00:00

Merge List:

+ 2022-08-04 85d87b9c75 all: update vendored golang.org/x dependencies for Go 1.20 development
+ 2022-08-04 fb1bfd4d37 all: remove pre-Go 1.17 workarounds
+ 2022-08-04 44ff9bff0c runtime: clean up panic and deadlock lock ranks
+ 2022-08-04 f42dc0de74 runtime: make the lock rank DAG make more sense
+ 2022-08-04 d29a0282e9 runtime: add mayAcquire annotation for finlock
+ 2022-08-04 c5be4ed7df runtime: add missing trace lock edges
+ 2022-08-04 2b8a9a484f runtime: generate the lock ranking from a DAG description
+ 2022-08-04 ddfd639408 runtime: delete unused lock ranks
+ 2022-08-04 426ea5702b internal/dag: add a Graph type and make node order deterministic
+ 2022-08-04 d37cc9a8cd go/build, internal/dag: lift DAG parser into an internal package
+ 2022-08-04 ab0a94c6d3 cmd/dist: require Go 1.17 for building Go
+ 2022-08-04 1e3c19f3fe runtime: support riscv64 SV57 mode
+ 2022-08-03 f28fa952b5 make.bat, make.rc: show bootstrap toolchain version
+ 2022-08-03 87384801dc cmd/asm: update package doc to describe "-p" option
+ 2022-08-03 c6a2dada0d net: disable TestIPv6WriteMsgUDPAddrPortTargetAddrIPVersion [sic] on DragonflyBSD
+ 2022-08-02 29b9a328d2 runtime: trivial replacements of g in remaining files
+ 2022-08-02 c647264619 runtime: trivial replacements of g in signal_unix.go
+ 2022-08-02 399f50c9d7 runtime: tricky replacements of g in traceback.go
+ 2022-08-02 4509e951ec runtime: tricky replacements of g in proc.go
+ 2022-08-02 4400238ec8 runtime: trivial replacements of _g_ in remaining files
+ 2022-08-02 5999a28de8 runtime: trivial replacements of _g_ in os files
+ 2022-08-02 0e18cf6d09 runtime: trivial replacements of _g_ in GC files
+ 2022-08-02 4358a53a97 runtime: trivial replacements of _g_ in proc.go
+ 2022-08-02 b486518964 runtime: tricky replacements of _g_ in os3_solaris.go
+ 2022-08-02 54a0ab3f7b runtime: tricky replacements of _g_ in os3_plan9.go
+ 2022-08-02 4240ff764b runtime: tricky replacements of _g_ in signal_windows.go
+ 2022-08-02 8666d89ca8 runtime: tricky replacements of _g_ in signal_unix.go
+ 2022-08-02 74cee276fe runtime: tricky replacements of _g_ in trace.go
+ 2022-08-02 222799fde6 runtime: tricky replacements of _g_ in mgc.go
+ 2022-08-02 e9d7f54a1a runtime: tricky replacements of _g_ in proc.go
+ 2022-08-02 5e8d261918 runtime: rename _p_ to pp
+ 2022-08-02 0ad2ec6596 runtime: clean up dopanic_m
+ 2022-08-02 7e952962df runtime: clean up canpanic
+ 2022-08-02 9dbc0f3556 runtime: fix outdated g.m comment in traceback.go
+ 2022-08-02 d723df76da internal/goversion: update Version to 1.20
+ 2022-08-02 1b7e71e8ae all: disable tests that fail on Alpine
+ 2022-08-01 f2a9f3e2e0 test: improve generic type assertion test
+ 2022-08-01 27038b70f8 cmd/compile: fix wrong dict pass condition for type assertions
+ 2022-08-01 e99f53fed9 doc: move Go 1.19 release notes to x/website
+ 2022-08-01 8b13a073a1 doc: mention removal of cmd/compile's -importmap and -installsuffix flags
+ 2022-08-01 e95fd4c238 doc/go1.19: fix typo: EM_LONGARCH -> EM_LOONGARCH
+ 2022-08-01 dee3efd9f8 doc/go1.19: fix a few links that were missing trailing slashes
+ 2022-07-30 f32519e5fb runtime: fix typos
+ 2022-07-29 9a2001a8cc cmd/dist: always pass -short=true with -quick
+ 2022-07-28 5c8ec89cb5 doc/go1.19: minor adjustments and links
+ 2022-07-28 417be37048 doc/go1.19: improve the loong64 release notes
+ 2022-07-28 027855e8d8 os/exec: add GODEBUG setting to opt out of ErrDot changes

Change-Id: Idc0fbe93978c0dff7600b90a2c3ecc067fd9f5f2

all: update vendored golang.org/x dependencies for Go 1.20 development

2022-08-04T17:12:04+00:00

Go 1.20 development is just beginning. This is a time to update all
golang.org/x/... module versions that contribute packages to the std
and cmd modules in the standard library to latest master versions.

This CL holds back some of the available updates to the x/net module
due to go.dev/issue/54259. It'll be updated in a later separate pass.
x/tools is also held back a bit to avoid pulling in too new of x/net.

For #36905.
For #53812.
Updates #54259.

Change-Id: Iaefe6a343a02cc5ceb85c15125882d64dd372627
Reviewed-on: https://go-review.googlesource.com/c/go/+/421334
Reviewed-by: Dmitri Shuralyov 
Run-TryBot: Dmitri Shuralyov 
TryBot-Result: Gopher Robot 
Reviewed-by: Matthew Dempsky 
Auto-Submit: Dmitri Shuralyov

all: remove pre-Go 1.17 workarounds

2022-08-04T17:05:18+00:00

The Go bootstrap toolchain requirement is now Go 1.17.
We can finally delete all these pre-Go 1.17 workarounds.

For #44505.

Change-Id: I59d4dff1cde23da022892b5b6a116eb3dbad9ce4
Reviewed-on: https://go-review.googlesource.com/c/go/+/420903
Auto-Submit: Dmitri Shuralyov 
Run-TryBot: Russ Cox 
Reviewed-by: Austin Clements 
TryBot-Result: Gopher Robot

runtime: clean up panic and deadlock lock ranks

2022-08-04T15:31:49+00:00

I'm not entirely sure why these locks are currently ranked "deadlock <
panic" since we drop panic before acquiring deadlock, and we actually
want deadlock to be below panic because panic is implicitly below
everything else and we want deadlock to be, too. My best guess is that
we had this edge because we intentionally acquire deadlock twice to
deadlock, and that causes the lock rank checking to panic on the
second acquire.

Fix this in a more sensible way by capturing that deadlock can be
acquired in a self-cycle and flipping the rank to "panic < deadlock"
to express that deadlock needs to be under all other locks, just like
panic.

For #53789.

Change-Id: I8809e5d102ce473bd3ace0ba07bf2200ef60263f
Reviewed-on: https://go-review.googlesource.com/c/go/+/418719
TryBot-Result: Gopher Robot 
Reviewed-by: Michael Pratt 
Run-TryBot: Austin Clements

runtime: make the lock rank DAG make more sense

2022-08-04T15:31:48+00:00

This groups, comments, and generally reorganizes the lock rank graph
description by subsystem. It also introduces several pseudo-nodes that
more cleanly describe the inherent layering of lock ranks by
subsystem.

I believe this doesn't actually change the graph, but haven't verified
this.

For #53789.

Change-Id: I72f332f5a23b8217c7dc1b21411631ad48cee4b0
Reviewed-on: https://go-review.googlesource.com/c/go/+/418718
TryBot-Result: Gopher Robot 
Run-TryBot: Austin Clements 
Reviewed-by: Michael Pratt

runtime: add mayAcquire annotation for finlock

2022-08-04T15:31:46+00:00

We're missing lock edges to finlock that happen only rarely. Anything
that calls mallocgc can potentially trigger sweeping, which can
potentially queue a finalizer, which acquires finlock. While this can
happen on any malloc, it happens relatively rarely, so we simply
haven't seen some of the lock edges that could happen.

Add a mayAcquire annotation to mallocgc to capture the possibility of
acquiring finlock.

With this change, we add "fin" to the set of "malloc" locks. Several
of these edges were already there, but not quite all of them.

This was found by inspecting the rank graph for things that didn't
make sense.

For #53789.

Change-Id: Idc10ce6f250596b0c07ba07ac93f2198fb38c22b
Reviewed-on: https://go-review.googlesource.com/c/go/+/418717
Run-TryBot: Austin Clements 
Reviewed-by: Michael Pratt 
TryBot-Result: Gopher Robot

runtime: add missing trace lock edges

2022-08-04T15:31:45+00:00

We're missing lock edges to trace.lock that happen only rarely. Any
trace event can potentially fill up a trace buffer and acquire
trace.lock in order to flush the buffer, but this happens relatively
rarely, so we simply haven't seen some of these lock edges that could
happen.

With this change, we promote "fin, notifyList < traceStackTab" to
"fin, notifyList < trace" and now everything that emits trace events
with a P enters the tracer lock ranks via "trace", rather than some
things entering at "trace" and others at "traceStackTab".

This was found by inspecting the rank graph for things that didn't
make sense.

Ideally we would add a mayAcquire annotation that any trace event can
potentially acquire trace.lock, but there are actually cases that
violate this ranking right now. This is #53979. The chance of a lock
cycle is extremely low given the number of conditions that have to
happen simultaneously.

For #53789.

Change-Id: Ic65947d27dee88d2daf639b21b2c9d37552f0ac0
Reviewed-on: https://go-review.googlesource.com/c/go/+/418716
Reviewed-by: Michael Pratt 
Run-TryBot: Austin Clements 
TryBot-Result: Gopher Robot

runtime: generate the lock ranking from a DAG description

2022-08-04T15:31:44+00:00

Currently, the runtime lock rank graph is maintained manually in a
large set of arrays that give the partial order and a manual
topological sort of this partial order. Any changes to the rank graph
are difficult to reason about and hard to review, as well as likely to
cause merge conflicts. Furthermore, because the partial order is
manually maintained, it's not actually transitively closed (though
it's close), meaning there are many cases where rank a can be acquired
before b and b before c, but a cannot be acquired before c. While this
isn't technically wrong, it's very strange in the context of lock
ordering.

Replace all of this with a much more compact, readable, and
maintainable description of the rank graph written in the internal/dag
graph language. We statically generate the runtime structures from
this description, which has the advantage that the parser doesn't have
to run during runtime initialization and the structures can live in
static data where they can be accessed from any point during runtime
init.

The current description was automatically generated from the existing
partial order, combined with a transitive reduction. This ensures it's
correct, but it could use some manual messaging to call out the
logical layers and add some structure.

We do lose the ad hoc string names of the lock ranks in this
translation, which could mostly be derived from the rank constant
names, but not always. I may bring those back but in a more uniform
way.

We no longer need the tests in lockrank_test.go because they were
checking that we manually maintained the structures correctly.

Fixes #53789.

Change-Id: I54451d561b22e61150aff7e9b8602ba9737e1b9b
Reviewed-on: https://go-review.googlesource.com/c/go/+/418715
Run-TryBot: Austin Clements 
Reviewed-by: Michael Pratt 
TryBot-Result: Gopher Robot

runtime: delete unused lock ranks

2022-08-04T15:31:43+00:00

For #53789.

Change-Id: Ic7379afcfdcc47b541bac9b44b5bc6b43604fc0a
Reviewed-on: https://go-review.googlesource.com/c/go/+/418714
Reviewed-by: Michael Pratt 
TryBot-Result: Gopher Robot 
Run-TryBot: Austin Clements

internal/dag: add a Graph type and make node order deterministic

2022-08-04T15:31:42+00:00

The go/types package doesn't care about node ordering because it's
just querying paths in the graph, but we're about to use this for the
runtime lock graph, and there we want determinism.

For #53789.

Change-Id: Ic41329bf2eb9a3a202f97c21c761ea588ca551c8
Reviewed-on: https://go-review.googlesource.com/c/go/+/418593
Reviewed-by: Michael Pratt 
TryBot-Result: Gopher Robot 
Run-TryBot: Austin Clements