Currently, package runtime contains the definition of reflect.call,
even though it's just a jump to runtime.reflectcall. This "push"
symbol is confusing, since it's not clear where the definition of
reflect.call comes from when you're in the reflect package.
Replace this with a "pull" symbol: the runtime now defines only
runtime.reflectcall and package reflect uses a go:linkname to access
this symbol directly. This makes it clear where reflect.call is coming
from without any spooky action at a distance and eliminates all of the
definitions of reflect.call in the runtime.
Change-Id: I3ec73cd394efe9df8d3061a57c73aece2e7048dd
Reviewed-on: https://go-review.googlesource.com/c/148657
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
This cleanup was proposed in CL 148937. The branch is already ended with
a continue, so remove continues from subbranches and use an else-if.
Change-Id: Iaf6eb57afc84e25862f99a342f5824e315bcdcb7
Reviewed-on: https://go-review.googlesource.com/c/148922
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This change fixes incorrect formatting in mheap.go (the result of my
previous heap scavenging changes) and map_test.go.
Change-Id: I2963687504abdc4f0cdf2f0c558174b3bc0ed2df
Reviewed-on: https://go-review.googlesource.com/c/148977
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
We have an existing optimization that recognizes
memory moves of the form A -> B -> C and converts
them into A -> C, in the hopes that the store to
B will be end up being dead and thus eliminated.
However, when A, B, and C are large types,
the front end sometimes emits VarDef ops for the moves.
This change adds an optimization to match that pattern.
This required changing an old compiler test.
The test assumed that a temporary was required
to deal with a large return value.
With this optimization in place, that temporary
ended up being eliminated.
Triggers 649 times during 'go build -a std cmd'.
Cuts 16k off cmd/go.
name old object-bytes new object-bytes delta
Template 507kB ± 0% 507kB ± 0% -0.15% (p=0.008 n=5+5)
Unicode 225kB ± 0% 225kB ± 0% ~ (all equal)
GoTypes 1.85MB ± 0% 1.85MB ± 0% ~ (all equal)
Flate 328kB ± 0% 328kB ± 0% ~ (all equal)
GoParser 402kB ± 0% 402kB ± 0% -0.00% (p=0.008 n=5+5)
Reflect 1.41MB ± 0% 1.41MB ± 0% -0.20% (p=0.008 n=5+5)
Tar 458kB ± 0% 458kB ± 0% ~ (all equal)
XML 601kB ± 0% 599kB ± 0% -0.21% (p=0.008 n=5+5)
Change-Id: I9b5f25c8663a0b772ad1ee51fa61f74b74d26dd3
Reviewed-on: https://go-review.googlesource.com/c/143479
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Munday <mike.munday@ibm.com>
These issues were found by the new vet's nilness check. The variables
were already checked against nil, so remove extra checks.
Change-Id: Ie252ccfcc755f3d06f691f354bf13d5a623fe17b
Reviewed-on: https://go-review.googlesource.com/c/148937
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
When a goroutine enters a syscall, its M unwires from its P to allow
the P to be retaken by another M if the syscall is slow. The M retains a
reference to its old P, however, so that if its old P has not been
retaken when the syscall returns, it can quickly reacquire that P.
The implementation, however, was confusing, as it left the reference to
the potentially-retaken P in m.p, which implied that the P was still
wired.
Make the code clearer by enforcing the invariant that m.p is never
stale. entersyscall now moves m.p to m.oldp and sets m.p to 0;
exitsyscall does the reverse, provided m.oldp has not been retaken.
With this scheme in place, the issue described in #27660 (assertion
failures in the race detector) would have resulted in a clean segfault
instead of silently corrupting memory.
Change-Id: Ib3e03623ebed4f410e852a716919fe4538858f0a
Reviewed-on: https://go-review.googlesource.com/c/148899
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
n.Type and n.Left.Type are used heavily. Give them useful names.
We generate the type word frequently. Make it a closure.
(We don't want to generate it up front, since there are some code
paths that don't need it, and generating it has side-effects.)
Simplify and document the final call construction.
Follow-up to address feedback on CL 147360.
Change-Id: I251134a55cf80d8b1676280a345d150f2288c09a
Reviewed-on: https://go-review.googlesource.com/c/147538
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
With this change, callbacks returned by syscall/js.NewCallback
get executed synchronously. This is necessary for the APIs of
many JavaScript libraries.
A callback triggered during a call from Go to JavaScript gets executed
on the same goroutine. A callback triggered by JavaScript's event loop
gets executed on an extra goroutine.
Fixes#26045Fixes#27441
Change-Id: I591b9e85ab851cef0c746c18eba95fb02ea9e85b
Reviewed-on: https://go-review.googlesource.com/c/142004
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Create a new node for OSLICEHEADER nodes to ensure typechecks are applied.
Add nil checks for OSLICEHEADER type and pointer parameters
for better error messages when these are not set.
Improve formatting of OSLICEHEADER nodes in compiler error messages.
Change-Id: Idea8f41bb4beb636f0e1fc381ff8d79b1d44fbae
Reviewed-on: https://go-review.googlesource.com/c/146997
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
It can be used to set the Go language version used by the module.
RELNOTES=yes
Updates #28221
Change-Id: Ief0dd185c01195a17be20dff8627c80943c436e7
Reviewed-on: https://go-review.googlesource.com/c/147282
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
When creating a go.mod file, add a go statement mentioning the current
Go version. We can be reasonably confident that the current version is
able to build the module. This is as described in the language
transition proposal at https://golang.org/issue/28221.
Updates #28221
Change-Id: I70a99b3a53f4b6c0288da07473c5a71bb28cd86f
Reviewed-on: https://go-review.googlesource.com/c/147281
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
This issue was found by the new vet's nilness check. _defer was already
checked against nil, so don't check it again.
Change-Id: I78725eaec7234b262b3c941e06441ca57f82bdd9
Reviewed-on: https://go-review.googlesource.com/c/148917
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This works around what appears to be a bug in current clang (2018-11-09).
Details are in the comment in the code.
Change-Id: Ib4783b6c03d531c69ebc4cb0ac023bea5bee7d40
Reviewed-on: https://go-review.googlesource.com/c/148819
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
cgocall could previously invoke the race detector on an M whose P had
been retaken. The race detector would attempt to use the P-local state
from this stale P, racing with the thread that was actually wired to
that P. The result was memory corruption of ThreadSanitizer's internal
data structures that presented as hard-to-understand assertion failures
and segfaults.
Reorder cgocall so that it always acquires a P before invoking the race
detector, and add a test that stresses the interaction between cgo and
the race detector to protect against future bugs of this kind.
Fixes#27660.
Change-Id: Ide93f96a23490314d6647547140e0a412a97f0d4
Reviewed-on: https://go-review.googlesource.com/c/148717
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
This change fixes a bug wherein freeing a scavenged span that didn't
coalesce with any neighboring spans would result in that span getting
scavenged again. This case may actually be a common occurance because
"freeing" span trimmings and newly-grown spans end up using the same
codepath. On systems where madvise is relatively expensive, this can
have a large performance impact.
This change also cleans up some of this logic in freeSpanLocked since
a number of factors made the coalescing code somewhat difficult to
reason about with respect to scavenging. Notably, the way the
needsScavenge boolean is handled could be better expressed and the
inverted conditions (e.g. !after.released) can make things even more
confusing.
Fixes#28595.
Change-Id: I75228dba70b6596b90853020b7c24fbe7ab937cf
Reviewed-on: https://go-review.googlesource.com/c/147559
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
During walkexpr, we were assessing whether shifts were bounded.
However, that information was dropped on the floor during SSA conversion.
The SSA backend already finds all bounded shifts that walkexpr could have,
and at negligible extra cost (0.02% in alloc, CPU undetectable).
Change-Id: Ieda1af1a2a3ec99bfdc2b0b704c9b80ce8a34486
Reviewed-on: https://go-review.googlesource.com/c/148897
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This change makes use of the cc versions of the AND, OR, XOR
instructions, omitting the need for a CMP instruction.
In many test programs and in the go binary, this reduces the
size of 20-30 functions by at least 1 instruction, many in
runtime.
Testcase added to test/codegen/comparisons.go
Change-Id: I6cc1ca8b80b065d7390749c625bc9784b0039adb
Reviewed-on: https://go-review.googlesource.com/c/143059
Reviewed-by: Carlos Eduardo Seo <cseo@linux.vnet.ibm.com>
Reviewed-by: Michael Munday <mike.munday@ibm.com>
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
When main.main returns, the process exits, so there's no need to cancel contexts.
This change was initially reviewed as
https://go-review.googlesource.com/c/go/+/106915/4
but somehow I messed up and committed patchset 5, which was
effectively empty.
Change-Id: Ic4250eb6563af9bc734e429aafc7081ca7d0e012
Reviewed-on: https://go-review.googlesource.com/c/148758
Reviewed-by: Alan Donovan <adonovan@google.com>
This change introduces two optimizations together,
one for recursive and one for non-recursive stacks.
For recursive stacks, we introduce the new entry
at the beginning of the cache, so it can be found first.
This adds an extra read and write.
While we're here, switch from fastrandn, which does a multiply,
to fastrand % n, which does a shift.
For non-recursive stacks, split the cache from [16]pcvalueCacheEnt
into [2][8]pcvalueCacheEnt, and add a very cheap associative lookup.
name old time/op new time/op delta
StackCopyPtr-8 118ms ± 1% 106ms ± 2% -9.56% (p=0.000 n=17+18)
StackCopy-8 95.8ms ± 1% 87.0ms ± 3% -9.11% (p=0.000 n=19+20)
StackCopyNoCache-8 135ms ± 2% 139ms ± 1% +3.06% (p=0.000 n=19+18)
During make.bash, the association function used has this return distribution:
percent count return value
53.23% 678797 1
46.74% 596094 0
It is definitely not perfect, but it is pretty good,
and that's all we need.
Change-Id: I2cabb1d26b99c5111bc28f427016a2a5e6c620fd
Reviewed-on: https://go-review.googlesource.com/c/110564
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Pointers to compound objects (structs, slices, arrays, maps) are only
followed by fmt if the pointer is at the top level of an argument. This
is to minimise the chances of fmt running into loops.
However, vet did not follow this rule. It likely doesn't help that fmt
does not document that restriction well, which is being tracked in
#28625.
Updates #27672.
Change-Id: Ie9bbd9b974eda5ab9a285986d207ef92fca4453e
Reviewed-on: https://go-review.googlesource.com/c/147997
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>
fmt's godoc reads:
For compound objects, the elements are printed using these
rules, recursively, laid out like this:
struct: {field0 field1 ...}
array, slice: [elem0 elem1 ...]
maps: map[key1:value1 key2:value2 ...]
pointer to above: &{}, &[], &map[]
That is, a pointer to a struct, array, slice, or map, can be correctly
printed by fmt if the type pointed to can be printed without issues.
vet was only following this rule for pointers to structs, omitting
arrays, slices, and maps. Fix that, and add tests for all the
combinations.
Updates #27672.
Change-Id: Ie61ebe1fffc594184f7b24d7dbf72d7d5de78309
Reviewed-on: https://go-review.googlesource.com/c/147758
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>
This optimization is not sound if A, B, or C
might overlap with each other.
Thanks to Michael Munday for pointing this
out during the review of CL 143479.
This reduces the number of times this optimization
triggers during make.bash from 386 to 74.
This is unfortunate, but I don't see an obvious way around it,
short of souping up the disjointness analysis.
name old object-bytes new object-bytes delta
Template 507kB ± 0% 507kB ± 0% +0.13% (p=0.008 n=5+5)
Unicode 225kB ± 0% 225kB ± 0% ~ (all equal)
GoTypes 1.85MB ± 0% 1.85MB ± 0% +0.02% (p=0.008 n=5+5)
Flate 328kB ± 0% 328kB ± 0% ~ (all equal)
GoParser 402kB ± 0% 402kB ± 0% ~ (all equal)
Reflect 1.41MB ± 0% 1.41MB ± 0% ~ (all equal)
Tar 457kB ± 0% 458kB ± 0% +0.20% (p=0.008 n=5+5)
XML 600kB ± 0% 601kB ± 0% +0.03% (p=0.008 n=5+5)
Change-Id: Ida408cb627145ba9faf473a78606f050c2f3f51c
Reviewed-on: https://go-review.googlesource.com/c/145208
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Munday <mike.munday@ibm.com>
This CL add support for converting a returned cursor (presented
to this package as a driver.Rows) and scanning it into a *Rows.
Fixes#28515
Change-Id: Id8191c568dc135af9e5e8555efcd01987708edcb
Reviewed-on: https://go-review.googlesource.com/c/145738
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Cleans things up quite a bit.
There's still a few more, like runtime.cmpstring, which might also
be worth fixing.
Change-Id: Ide18dd621efc129cc686db223f47fa0b044b5580
Reviewed-on: https://go-review.googlesource.com/c/148578
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
The environment variable is no longer necessary as we now plan to
transition to the new vet by replacing it in a single step,
and we really don't want to add more environment variables.
Fixes#28636
Change-Id: Ib85e5c0d61213b7b9f6a53d9376fec29525df971
Reviewed-on: https://go-review.googlesource.com/c/148497
Run-TryBot: Alan Donovan <adonovan@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
This is a simple tweak to allow a bit more mid-stack inlining.
In cases like this:
func f() {
g()
}
We'd really like to inline f into its callers. It can't hurt.
We implement this optimization by making calls a bit cheaper, enough
to afford a single call in the function body, but not 2.
The remaining budget allows for some argument modification, or perhaps
a wrapping conditional:
func f(x int) {
g(x, 0)
}
func f(x int) {
if x > 0 {
g()
}
}
Update #19348
Change-Id: Ifb1ea0dd1db216c3fd5c453c31c3355561fe406f
Reviewed-on: https://go-review.googlesource.com/c/147361
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: David Chase <drchase@google.com>
Add unexported unlinkat, openat, and fstatat calls, so that
the internal/syscall/unix package can use them.
Change-Id: I1df81ecae6427211dd392ec68c9f020fe131a526
Reviewed-on: https://go-review.googlesource.com/c/148457
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Now, this is embarrassing. While preparing CL 142818, I noticed a
possible vulnerability in the existing code which I was rewriting. I
took a note to go back and assess if it was indeed an issue, and in case
start the security release process. The note unintentionally slipped
into the commit. Fortunately, there was no vulnerability.
What caught my eye was that I had fixed the calculation of the minimum
encrypted payload length from
roundUp(explicitIVLen+macSize+1, blockSize)
to (using the same variable names)
explicitIVLen + roundUp(macSize+1, blockSize)
The explicit nonce sits outside of the encrypted payload, so it should
not be part of the value rounded up to the CBC block size.
You can see that for some values of the above, the old result could be
lower than the correct value. An unexpectedly short payload might cause
a panic during decryption (a DoS vulnerability) or even more serious
issues due to the constant time code that follows it (see for example
Yet Another Padding Oracle in OpenSSL CBC Ciphersuites [1]).
In practice, explicitIVLen is either zero or equal to blockSize, so it
does not change the amount of rounding up necessary and the two
formulations happen to be identical. Nothing to see here.
It looked more suspicious than it is in part due to the fact that the
explicitIVLen definition moved farther into hc.explicitNonceLen() and
changed name from IV (which suggests a block length) to nonce (which
doesn't necessarily). But anyway it was never meant to surface or be
noted, except it slipped, so here we are for a boring explanation.
[1] https://blog.cloudflare.com/yet-another-padding-oracle-in-openssl-cbc-ciphersuites/
Change-Id: I365560dfe006513200fa877551ce7afec9115fdf
Reviewed-on: https://go-review.googlesource.com/c/147637
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Miscellaneous additional conversions from raw syscalls
to using their libc equivalent.
Update #17490
Change-Id: If9ab22cc1d676c1f20fb161ebf02b0c28f71585d
Reviewed-on: https://go-review.googlesource.com/c/148257
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Pass the Go language version specified in the go.mod file to
cmd/compile.
Also, change the behavior when the go.mod file requests a Go version
that is later than the current one. Previously cmd/go would give a
fatal error in this situation. With this change it attempts the
compilation, and if (and only if) the compilation fails it adds a note
saying that the requested Go version is newer than the known version.
This is as described in https://golang.org/issue/28221.
Updates #28221.
Change-Id: I46803813e7872d4a418a3fd5299880be3b73a971
Reviewed-on: https://go-review.googlesource.com/c/147278
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
This will be used by later commits in this sequence.
Updates #28221
Change-Id: I2b22b9f88a0183636cde9509606f03f079eb33f1
Reviewed-on: https://go-review.googlesource.com/c/147277
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
There are still some references to the bare Syscall functions
in the stdlib. I will root those out in a following CL.
(This CL is big enough as it is.)
Most are in vendor directories:
cmd/vendor/golang.org/x/sys/unix/
vendor/golang_org/x/net/route/syscall.go
syscall/bpf_bsd.go
syscall/exec_unix.go
syscall/flock.go
Update #17490
Change-Id: I69ab707811530c26b652b291cadee92f5bf5c1a4
Reviewed-on: https://go-review.googlesource.com/c/141639
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Elias Naur <elias.naur@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
It is possible to create certain recursive type declarations involving
alias types which cause the type-checker to produce an (invalid) type
for the alias because it is not yet available. By type-checking alias
declarations in a 2nd phase, the problem is mitigated a bit since it
requires more convoluted alias declarations for the problem to appear.
Also re-enable testing of fixedbugs/issue27232.go again (which was the
original cause for this change).
Updates #28576.
Change-Id: If6f9656a95262e6575b01c4a003094d41551564b
Reviewed-on: https://go-review.googlesource.com/c/147597
Reviewed-by: Alan Donovan <adonovan@google.com>
