… empty structs

For #40954

Change-Id: I6a30aed31a16e820817f4ca5c7f591222e922946
Reviewed-on: https://go-review.googlesource.com/c/go/+/277432
Trust: Ian Lance Taylor <[email protected]>
Reviewed-by: Keith Randall <[email protected]>
(cherry picked from commit 129bb19)
Reviewed-on: https://go-review.googlesource.com/c/go/+/278573
Run-TryBot: Ian Lance Taylor <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>

…o release-branch.go1.15

Change-Id: I0b607475b3d767b712bfb3c9a350b32f3491517c

Fixes #43797

Change-Id: I3d791d0ac9ce0b523c78c649aaf5e339a7f63b76
Reviewed-on: https://go-review.googlesource.com/c/go/+/284797
Trust: Jay Conrod <[email protected]>
Run-TryBot: Jay Conrod <[email protected]>
Reviewed-by: Bryan C. Mills <[email protected]>
TryBot-Result: Go Bot <[email protected]>
(cherry picked from commit be28e5a)
Reviewed-on: https://go-review.googlesource.com/c/go/+/284799

… that support them

Fixes #43793

Change-Id: I3bf022a28b194f0089ea96d93e56bbd9fb7e0aa8
Reviewed-on: https://go-review.googlesource.com/c/go/+/285056
Trust: Roland Shoemaker <[email protected]>
Run-TryBot: Roland Shoemaker <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>

… source is volatile

Current optimization: When we copy a->b and then b->c, we might as well
copy a->c instead of b->c (then b might be dead and go away).

*Except* if a is a volatile location (might be clobbered by a call).
In that case, we really do want to copy a immediately, because there
might be a call before we can do the a->c copy.

User calls can't happen in between, because the rule matches up the
memory states. But calls inserted for memory barriers, particularly
runtime.typedmemmove, can.

(I guess we could introduce a register-calling-convention version
of runtime.typedmemmove, but that seems a bigger change than this one.)

Fixes #43575

Change-Id: Ifa518bb1a6f3a8dd46c352d4fd54ea9713b3eb1a
Reviewed-on: https://go-review.googlesource.com/c/go/+/282492
Trust: Keith Randall <[email protected]>
Trust: Josh Bleecher Snyder <[email protected]>
Run-TryBot: Keith Randall <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Josh Bleecher Snyder <[email protected]>
(cherry picked from commit 304f769)
Reviewed-on: https://go-review.googlesource.com/c/go/+/282558
Trust: Dmitri Shuralyov <[email protected]>

This test needs to run in GOPATH mode. It broke when a go.mod file was
added to github.com/golang/example. This change sets GO111MODULE=off,
which matches master since CL 255051.

Fixes #43861

Change-Id: I9ea109a99509fac3185756a0f0d852a84c677bf5
Reviewed-on: https://go-review.googlesource.com/c/go/+/285956
Trust: Jay Conrod <[email protected]>
Run-TryBot: Jay Conrod <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Bryan C. Mills <[email protected]>

Updates bundled http2 to x/net git rev 16c2bbf55 for:

	http2: send a nil error if we cancel a delayed body write
	https://golang.org/cl/288013

	http2: wait until the request body has been written
	https://golang.org/cl/288012

Created by:

go mod edit -replace=golang.org/x/net=golang.org/x/[email protected]
GOFLAGS='-mod=mod' go generate -run=bundle std
go mod edit -dropreplace=golang.org/x/net
go get -d golang.org/x/[email protected]
go mod tidy
go mod vendor

Fixes #42539

Change-Id: I299c6d4a67ebc036e45c978e4d03cba73717b363
Reviewed-on: https://go-review.googlesource.com/c/go/+/288112
Trust: Damien Neil <[email protected]>
Run-TryBot: Damien Neil <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>

…oking cgo

Previously, if CC was a path without separators (like gcc or clang),
we'd look it up in PATH in cmd/go using internal/execabs.LookPath,
then pass the resolved path to cgo in CC.

This caused a regression: if the directory in PATH containing CC has a
space, cgo splits it and interprets it as multiple arguments.

With this change, cmd/go no longer resolves CC before invoking
cgo. cgo does the path lookup on each invocation. This reverts the
security fix CL 284780, but that was redundant with the addition of
internal/execabs (CL 955304), which still protects us.

NOTE: This CL includes a related test fix from CL 286292.

Fixes #43860

Change-Id: I65d91a1e303856df8653881eb6e2e75a3bf95c49
Reviewed-on: https://go-review.googlesource.com/c/go/+/285873
Trust: Jay Conrod <[email protected]>
Run-TryBot: Jay Conrod <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Bryan C. Mills <[email protected]>
(cherry picked from commit a2cef9b)
Reviewed-on: https://go-review.googlesource.com/c/go/+/285954
Run-TryBot: Dmitri Shuralyov <[email protected]>

…resource section

The resource symbol may have been copied to the mmap'd
output buffer. If so, certain conditions can cause that
mmap'd output buffer to be munmap'd before we get a chance
to use it. To avoid any issues we copy the data to the heap
when the resource symbol exists.

Fixes #42384

Change-Id: I32ef5420802d7313a3d965b8badfbcfb9f0fba4a
GitHub-Last-Rev: 7b0f430
GitHub-Pull-Request: #42427
Reviewed-on: https://go-review.googlesource.com/c/go/+/268018
Run-TryBot: Carlos Amedee <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Russ Cox <[email protected]>
Reviewed-by: Cherry Zhang <[email protected]>
Reviewed-by: Than McIntosh <[email protected]>
Trust: Carlos Amedee <[email protected]>

…e reader

The code in the Go object file reader was casting a pointer to mmaped
memory into a large array prior to performing a read of the
relocations section:

	return (*[1<<20]Reloc)(unsafe.Pointer(&r.b[off]))[:n:n]

For very large object files, this artificial array isn't large enough
(that is, there are more than 1048576 relocs to read), so update the
code to use a larger artifical array size.

Fixes #43214.
Updates #41621.

Change-Id: Ic047c8aef4f8a3839f2e7e3594bce652ebd6bd5b
Reviewed-on: https://go-review.googlesource.com/c/go/+/278492
Run-TryBot: Than McIntosh <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Cherry Zhang <[email protected]>
Reviewed-by: Jeremy Faller <[email protected]>
Trust: Than McIntosh <[email protected]>
(cherry picked from commit f4e7a6b)
Reviewed-on: https://go-review.googlesource.com/c/go/+/278673

…Waiting status

Before this CL, the following sequence was possible:

* GC scavenger starts and sets up scavenge.timer
* GC calls readyForScavenger, but sysmon is sleeping
* program calls runtime.GOMAXPROCS to shrink number of processors
* procresize destroys a P, the one that scavenge.timer is on
* (*pp).destroy calls moveTimers, which gets to the scavenger timer
* scavenger timer is timerWaiting, and moveTimers clears t.pp
* sysmon wakes up and calls wakeScavenger
* wakeScavengers calls stopTimer on scavenger.timer, still timerWaiting
* stopTimer calls deltimer which loads t.pp, which is still nil
* stopTimer tries to increment deletedTimers on nil t.pp, and crashes

The point of vulnerability is the time that t.pp is set to nil by
moveTimers and the time that t.pp is set to non-nil by moveTimers,
which is a few instructions at most. So it's not likely and in
particular is quite unlikely on x86. But with a more relaxed memory
model the area of vulnerability can be somewhat larger. This appears
to tbe the cause of two builder failures in a few months on linux-mips.

This CL fixes the problem by making moveTimers change the status from
timerWaiting to timerMoving while t.pp is clear. That will cause
deltimer to wait until the status is back to timerWaiting, at which
point t.pp has been set again.

For #43712
Fixes #43833

Change-Id: I66838319ecfbf15be66c1fac88d9bd40e2295852
Reviewed-on: https://go-review.googlesource.com/c/go/+/284775
Trust: Ian Lance Taylor <[email protected]>
Reviewed-by: Michael Knyszek <[email protected]>
Reviewed-by: Michael Pratt <[email protected]>
(cherry picked from commit d2d155d)
Reviewed-on: https://go-review.googlesource.com/c/go/+/287092
Run-TryBot: Carlos Amedee <[email protected]>

Fixes #43406

Change-Id: I7d2b70098a4ba4dcb325fb0be076043789b86135
Reviewed-on: https://go-review.googlesource.com/c/go/+/280312
Run-TryBot: Elias Naur <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Ian Lance Taylor <[email protected]>
Trust: Elias Naur <[email protected]>
(cherry picked from commit 1d78139)
Reviewed-on: https://go-review.googlesource.com/c/go/+/289149

Change-Id: Ic8824cabbc8ae62360e0cda4b7c5604db7d405f3
Reviewed-on: https://go-review.googlesource.com/c/go/+/289694
Run-TryBot: Carlos Amedee <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Alexander Rakoczy <[email protected]>
Trust: Alexander Rakoczy <[email protected]>
Trust: Carlos Amedee <[email protected]>