delta/go-git.git/src/runtime, branch dev.typeparams

[dev.typeparams] all: merge master (46fd547) into dev.typeparams

2021-08-12T19:43:12+00:00

Conflicts:

- src/go/types/check_test.go

  CL 324730 on dev.typeparams changed the directory paths in TestCheck,
  TestExamples, and TestFixedbugs and renamed checkFiles to testFiles;
  whereas CL 337529 on master added a new test case just above them and
  that used checkFiles.

Merge List:

+ 2021-08-12 46fd547d89 internal/goversion: update Version to 1.18
+ 2021-08-12 5805efc78e doc/go1.17: remove draft notice
+ 2021-08-12 39634e7dae CONTRIBUTORS: update for the Go 1.17 release
+ 2021-08-12 095bb790e1 os/exec: re-enable LookPathTest/16
+ 2021-08-11 dea23e9ca8 src/make.*: make --no-clean flag a no-op that prints a warning
+ 2021-08-11 d4c0ed26ac doc/go1.17: linker passes -I to extld as -Wl,--dynamic-linker
+ 2021-08-10 1f9c9d8530 doc: use "high address/low address" instead of "top/bottom"
+ 2021-08-09 f1dce319ff cmd/go: with -mod=vendor, don't panic if there are duplicate requirements
+ 2021-08-09 7aeaad5c86 runtime/cgo: when using msan explicitly unpoison cgoCallers
+ 2021-08-08 507cc341ec doc: add example for conversion from slice expressions to array ptr
+ 2021-08-07 891547e2d4 doc/go1.17: fix a typo introduced in CL 335135
+ 2021-08-06 8eaf4d16bc make.bash: do not overwrite GO_LDSO if already set
+ 2021-08-06 63b968f4f8 doc/go1.17: clarify Modules changes
+ 2021-08-06 70546f6404 runtime: allow arm64 SEH to be called if illegal instruction
+ 2021-08-05 fd45e267c2 runtime: warn that KeepAlive is not an unsafe.Pointer workaround
+ 2021-08-04 6e738868a7 net/http: speed up and deflake TestCancelRequestWhenSharingConnection
+ 2021-08-02 8a7ee4c51e io/fs: don't use absolute path in DirEntry.Name doc
+ 2021-07-31 b8ca6e59ed all: gofmt
+ 2021-07-30 b7a85e0003 net/http/httputil: close incoming ReverseProxy request body
+ 2021-07-29 70fd4e47d7 runtime: avoid possible preemption when returning from Go to C
+ 2021-07-28 9eee0ed439 cmd/go: fix go.mod file name printed in error messages for replacements
+ 2021-07-28 b39e0f461c runtime: don't crash on nil pointers in checkptrAlignment
+ 2021-07-27 7cd10c1149 cmd/go: use .mod instead of .zip to determine if version has go.mod file
+ 2021-07-27 c8cf0f74e4 cmd/go: add missing flag in UsageLine
+ 2021-07-27 7ba8e796c9 testing: clarify T.Name returns a distinct name of the running test
+ 2021-07-27 33ff155970 go/types: preserve untyped constants on the RHS of a shift expression
+ 2021-07-26 840e583ff3 runtime: correct variable name in comment
+ 2021-07-26 bfbb288574 runtime: remove adjustTimers counter
+ 2021-07-26 9c81fd53b3 cmd/vet: add missing copyright header

Change-Id: Ia80604d24c6f4205265683024e3100769cf32065

[dev.typeparams] runtime, internal/bytealg: remove regabi fallback code on AMD64

2021-08-11T17:08:54+00:00

As we commit to always enabling register ABI on AMD64, remove the
fallback code.

Change-Id: I30556858ba4bac367495fa94f6a8682ecd771196
Reviewed-on: https://go-review.googlesource.com/c/go/+/341152
Trust: Cherry Mui 
Run-TryBot: Cherry Mui 
TryBot-Result: Go Bot 
Reviewed-by: Michael Knyszek 
Reviewed-by: Austin Clements

[dev.typeparams] internal/buildcfg: always enable regabi on AMD64

2021-08-11T16:59:43+00:00

In Go 1.17 we added register ABI on AMD64 on Linux/macOS/Windows
as a GOEXPERIMENT, on by default. In Go 1.18, we commit to always
enabling register ABI on AMD64.

Now "go build" for AMD64 always have goexperiment.regabi* tags
set. However, at bootstrapping cmd/dist does not set the tags
when building go_bootstrap. For this to work, unfortunately, we
need to hard-code AMD64 to use register ABI in runtime code.

Change-Id: I0b31e678e186b9cdeeb8502cd9e38ed0d7e72d4f
Reviewed-on: https://go-review.googlesource.com/c/go/+/341151
Trust: Cherry Mui 
Run-TryBot: Cherry Mui 
TryBot-Result: Go Bot 
Reviewed-by: Michael Knyszek 
Reviewed-by: Austin Clements

doc: use "high address/low address" instead of "top/bottom"

2021-08-10T01:13:06+00:00

The current document uses the "top" and "bottom" when talking
about the address within a frame, which may easily lead to
misunderstandings. This patch directly uses "high address"
and "low address" to make the expression clearer.

Change-Id: I7469330bbdc158672d7f0314fe6680ebdd9ab79a
Reviewed-on: https://go-review.googlesource.com/c/go/+/339369
Trust: fannie zhang 
Reviewed-by: Austin Clements 
Reviewed-by: Cherry Mui

[dev.typeparams] cmd/compile: simplify interface conversions

2021-08-09T16:10:20+00:00

Simplify the implementation of interface conversions in the compiler.
Don't pass fields that aren't needed (the data word, usually) to the runtime.

For generics, we need to put a dynamic type in an interface. The new
dataWord function is exactly what we need (the type word will come
from a dictionary).

Change-Id: Iade5de5c174854b65ad248f35c7893c603f7be3d
Reviewed-on: https://go-review.googlesource.com/c/go/+/340029
Trust: Keith Randall 
Trust: Dan Scales 
Run-TryBot: Keith Randall 
TryBot-Result: Go Bot 
Reviewed-by: Dan Scales

runtime/cgo: when using msan explicitly unpoison cgoCallers

2021-08-09T14:48:39+00:00

This avoids an incorrect msan uninitialized memory report when using
runtime.SetCgoTraceback when a signal occurs while the fifth argument
register is undefined. See the issue for more details.

Fixes #47543

Change-Id: I3d1b673e2c93471ccdae0171a99b88b5a6062840
Reviewed-on: https://go-review.googlesource.com/c/go/+/339902
Trust: Ian Lance Taylor 
Run-TryBot: Ian Lance Taylor 
TryBot-Result: Go Bot 
Reviewed-by: Austin Clements

runtime: allow arm64 SEH to be called if illegal instruction

2021-08-06T16:51:12+00:00

DLLs built with recent Microsoft toolchains for ARM64 test for ARMv8.1
atomics by potentially calling an illegal instruction, and then trapping
the exception to disable use of them by way of a structured exception
handler. However, vectored exception handlers are always called before
structured exception handlers. When LoadLibrary-ing DLLs that do this
probing during initialization, our lastcontinuehandler winds up being
called, and then crashing, but actually it should give execution back to
the library to handle the exception and fix up the state. So special
case this for arm64 with illegal instructions, and hope that we're not
masking other things in external DLLs that might more fatally trigger an
illegal instruction exception.

Updates #47576.

Change-Id: I341ab99cd8d513ae999b75596749d49779072022
Reviewed-on: https://go-review.googlesource.com/c/go/+/340070
Trust: Jason A. Donenfeld 
Run-TryBot: Jason A. Donenfeld 
TryBot-Result: Go Bot 
Reviewed-by: Brad Fitzpatrick 
Reviewed-by: Russ Cox

runtime: warn that KeepAlive is not an unsafe.Pointer workaround

2021-08-05T20:22:31+00:00

Even experienced users occasionally mistake that runtime.KeepAlive can
be used as a workaround for following the unsafe.Pointer safety rules,
but it cannot. Add an explicit warning to this effect to dissuade
users from trying to use it as such.

Fixes #47562.

Change-Id: I842e33a3e1c080933c6b1bd1b6318448adbf495c
Reviewed-on: https://go-review.googlesource.com/c/go/+/340269
Trust: Matthew Dempsky 
Reviewed-by: Ian Lance Taylor

[dev.typeparams] runtime: handle d.link carefully when freeing a defer

2021-08-04T15:51:58+00:00

CL 339396 allowed stack copying on entry to and during freedefer, but
this introduced a subtle bug: if d is heap-allocated, and d.link
points to a stack-allocated defer, stack copying during freedefer can
briefly introduce a stale pointer, which the garbage collector can
discover and panic about. This happens because d has already been
unlinked from the defer chain when freedefer is called, so stack
copying won't update stack pointers in it.

Fix this by making freedefer nosplit again and immediately clearing
d.link.

This should fix the longtest builders, which currently fail on
GOMAXPROCS=2 runtime -cpu=1,2,4 -quick in the TestDeferHeapAndStack
test.

This seems like the simplest fix, but it just deals with the subtlety
rather than eliminating it. Really, every call site of freedefer (of
which there are surprisingly many) has hidden subtlety between
unlinking the defer and calling freedefer. We could consolidate the
subtlety into each call site by requiring that they unlink the defer
and set d.link to nil before calling freedefer. freedefer could check
this condition like it checks that various other fields have already
been zeroed. A more radical option is to replace freedefer with
"popDefer", which would both pop the defer off the link and take care
of freeing it. There would still be a brief moment of subtlety, but it
would be in one place, in popDefer. Annoyingly, *almost* every call to
freedefer just pops the defer from the head of the G's list, but
there's one place when handling open-coded defers where we have to
remove a defer from the middle of the list. I'm inclined to first fix
that subtlety by only expanding open-coded defer records when they're
at the head of the defer list, and then revisit the popDefer idea.

Change-Id: I3130d2542c01a421a5d60e8c31f5379263219627
Reviewed-on: https://go-review.googlesource.com/c/go/+/339730
Trust: Austin Clements 
Run-TryBot: Austin Clements 
TryBot-Result: Go Bot 
Reviewed-by: Cherry Mui

[dev.typeparams] runtime: simplify freedefer

2021-08-03T21:23:25+00:00

Currently, freedefer manually zeros all the fields in the _defer
because simply assigning _defer{} used to cause a nosplit stack
overflow. freedefer is no longer nosplit, so go back to the simpler,
more robust code.

Change-Id: I881f557bab3b1ee7ab29b68e7fb56d0fe6d35d8d
Reviewed-on: https://go-review.googlesource.com/c/go/+/339669
Trust: Austin Clements 
Run-TryBot: Austin Clements 
TryBot-Result: Go Bot 
Reviewed-by: Cherry Mui