These workarounds predate proper DWARF support
and are no longer necessary.
Before this patch, running `/usr/bin/symbols go.o`
using the object in the c-archive would fail, causing
App Store rejections.
Fixes #31022 #28997
Change-Id: I6a210b6369c13038777c6e21e874e81afcb50c2f
Reviewed-on: https://go-review.googlesource.com/c/go/+/170377
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Michael Anthony Knyszek [Fri, 29 Mar 2019 16:02:05 +0000 (16:02 +0000)]
runtime: introduce treapForSpan to reduce code duplication
Currently which treap a span should be inserted into/removed from is
checked by looking at the span's properties. This logic is repeated in
four places. As this logic gets more complex, it makes sense to
de-duplicate this, so introduce treapForSpan instead which captures this
logic by returning the appropriate treap for the span.
Michael Anthony Knyszek [Sat, 9 Feb 2019 00:13:37 +0000 (00:13 +0000)]
runtime: add tests for runtime mTreap
This change exports the runtime mTreap in export_test.go and then adds a
series of tests which check that the invariants of the treap are
maintained under different operations. These tests also include tests
for the treap iterator type.
Also, we note that the find() operation on the treap never actually was
best-fit, so the tests just ensure that it returns an appropriately
sized span.
Michael Anthony Knyszek [Thu, 17 Jan 2019 20:05:20 +0000 (20:05 +0000)]
runtime: throw if scavenge necessary during coalescing
Currently when coalescing if two adjacent spans are scavenged, we
subtract their sizes from memstats and re-scavenge the new combined
span. This is wasteful however, since the realignment semantics make
this case of having to re-scavenge impossible.
In realign() inside of coalesce(), there was also a bug: on systems
where physPageSize > pageSize, we wouldn't realign because a condition
had the wrong sign. This wasteful re-scavenging has been masking this
bug this whole time. So, this change fixes that first.
Then this change gets rid of the needsScavenge logic and instead checks
explicitly for the possibility of unscavenged pages near the physical
page boundary. If the possibility exists, it throws. The intent of
throwing here is to catch changes to the runtime which cause this
invariant to no longer hold, at which point it would likely be
appropriate to scavenge the additional pages (and only the additional
pages) at that point.
golang.org/cl/121255 added close and re-open the directory when looping, prevent
us from missing some if previous iteration deleted files.
The CL introdued a bug. If we can not delete all entries in one request,
the looping never exits, causing RemoveAll hangs.
To fix that, simply discard the entries if we can not delete all of them
in one iteration, then continue reading entries and delete them.
Also make sure removeall_at return first error it encounters.
Fixes #29921
Change-Id: I8ec3a4c822d8d2d95d9f1ab71547879da395bc4a
Reviewed-on: https://go-review.googlesource.com/c/go/+/171099
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Keith Randall [Wed, 10 Apr 2019 18:06:58 +0000 (11:06 -0700)]
syscall: store skip count in file descriptor offset
Multiple calls to ReadDirent expect to return subsequent
portions of the directory listing. There's no place to store
our progress other than the file descriptor offset.
Fortunately, the file descriptor offset doesn't need to be
a real offset. We can store any int64 we want there.
Fixes #31368
Change-Id: I49e4e0e7ff707d3e96aa5d43e3b0199531013cde
Reviewed-on: https://go-review.googlesource.com/c/go/+/171477
Run-TryBot: Keith Randall <khr@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Elias Naur [Mon, 8 Apr 2019 21:12:52 +0000 (23:12 +0200)]
runtime: correct the TLS base offset on Android
CL 170955 set tlsg to the Android Q free TLS slot offset in the linker
data (16 on amd64, 8 on 386), offsetting all TLS relative access.
We need the 0'th slot (TLS_SLOT_SELF) at initialization, so
compensate with a corresponding negative offset.
Fixes the android/386 and android/amd64 builders broken by CL 170955.
bytes: optimize ToLower and ToUpper for ASCII-only case
Follow what CL 68370 and CL 76470 did for the respective functions in
package strings.
Also adjust godoc strings to match the respective strings functions and
mention the special case for ASCII-only byte slices which don't need
conversion.
cmd/cover: rename temporary directory prefix for consistency
This change renames the temporary directory prefix for testing to
go-testcover from gotestcover. It looks like other packages have the
"go-" prefix for temporary directories, such as go-build, go-tool-dist
and go-nettest.
OINDREGSP was used only for reading the results of a function call.
In recognition of that fact, rename it to ORESULT.
Along the way, trim down our handling of it to the bare minimum,
and rely on the increased clarity of ORESULT to inline nodarg.
Elias Naur [Sun, 7 Apr 2019 13:02:31 +0000 (15:02 +0200)]
cmd/go/internal/work: make toolchain builds reproducible when buildmode=pie
When buildmode=pie, external linking is forced, and our toolchain build id
will be included in the external build id, resulting in the building of
a toolchain tool will never reach a fixed point id.
More importantly, this change will make make.bash converge on self-hosted
Android builds (Android refuses to run non-PIE executables).
Fixes #31320
Updates #18968
Change-Id: Icb5db9f4b1b688afe37f4dafe261ffda580fa4e7
Reviewed-on: https://go-review.googlesource.com/c/go/+/170942
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Elias Naur [Sun, 7 Apr 2019 14:58:13 +0000 (16:58 +0200)]
cmd/dist: set buildmode=pie on Android
Android refuses to run non-PIE binaries, a restriction already
encoded in the cmd/go tool's buildModeInit function. This CL adds
the necessary flags to cmd/dist to make ./make.bash run on an
Android device.
Change-Id: I162084f573befaa41dcb47a2b78448bce5b83d35
Reviewed-on: https://go-review.googlesource.com/c/go/+/170943
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Keith Randall [Tue, 2 Apr 2019 22:00:54 +0000 (15:00 -0700)]
cmd/compile: get rid of unnecessary inline marks
If no other instruction mentions an inline mark, we can get rid of it.
This normally happens when the inlined function is empty, or when all
of its code is folded into other instructions.
Also use consistent statement-ness for inline mark positions, so that
more of them can be removed in favor of existing instructions.
Michael Anthony Knyszek [Mon, 11 Feb 2019 17:20:59 +0000 (17:20 +0000)]
runtime: use iterator instead of raw node for treap find
Right now the mTreap structure exposes the treapNode structure through
only one interface: find. There's no reason (performance or otherwise)
for exposing this, and we get a cleaner abstraction through the
iterators this way. This change also makes it easier to make changes to
the mTreap implementation without violating its interface.
Michael Anthony Knyszek [Thu, 31 Jan 2019 16:57:29 +0000 (16:57 +0000)]
runtime: merge codepaths in scavengeLargest
This change just makes the code in scavengeLargest easier to reason
about by reducing the number of exit points to the method. It should
still be correct either way because the condition checked at the end
(released > nbytes) will always be false if we return, but this just
makes the code a little easier to maintain.
The Modified field allows representation of extended timestamps, which provide more accuracy than the legacy MS-DOS timestamps.
The FileInfo method provides an implementation of the os.FileInfo interface for files inside archives.
With this change, we make FileInfo use the Modified field, if present, to return more detailed timestamps from its ModTime method.
Fixes #28350
Change-Id: Ia31b5b871a3e61df38a3a1325787ae23ea0b8088
GitHub-Last-Rev: 13e94be3f8ba58717911354146670fc2bc594692
GitHub-Pull-Request: golang/go#28352
Reviewed-on: https://go-review.googlesource.com/c/go/+/144382
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Nigel Tao [Sat, 6 Apr 2019 23:33:36 +0000 (09:33 +1000)]
image: deprecate ZP and ZR
They were added a very long time ago, as a convenience before Go had
struct literals. Today, it is better to use the zero-valued literal. For
example, the compiler cannot prove that ZP or ZR have not been modified.
Change-Id: I7469f1c751e91bf76fe1eab07b5772eccb5d6405
Reviewed-on: https://go-review.googlesource.com/c/go/+/171097 Reviewed-by: Nigel Tao <nigeltao@golang.org>
Keith Randall [Sat, 6 Apr 2019 19:42:51 +0000 (12:42 -0700)]
cmd/compile: remove AUNDEF opcode
This opcode was only used to mark unreachable code for plive to use.
plive now uses the SSA representation, so it knows locations are
unreachable because they are ends of Exit blocks. It doesn't need
these opcodes any more.
These opcodes actually used space in the binary, 2 bytes per undef
on x86 and more for other archs.
runtime: separate stack freeing from stack shrinking
Currently, shrinkstack will free the stack if the goroutine is dead.
There are only two places that call shrinkstack: scanstack, which will
never call it if the goroutine is dead; and markrootFreeGStacks, which
only calls it on dead goroutines.
Clean this up by separating stack freeing out of shrinkstack.
Austin Clements [Tue, 26 Mar 2019 01:16:33 +0000 (21:16 -0400)]
runtime: use acquirem/releasem more widely
We've copy-pasted the pattern of releasem in many places. This CL
replaces almost everywhere that manipulates g.m.locks and g.preempt
with calls to acquirem/releasem. There are a few where we do something
more complicated, like where exitsyscall has to restore the stack
bound differently depending on the preempt flag, which this CL leaves
alone.
Austin Clements [Tue, 26 Mar 2019 02:24:03 +0000 (22:24 -0400)]
runtime: fix sanity check in notetsleep
CL 3660 replaced m.gcing with m.preemptoff, but unintentionally
reversed the sense of part of a sanity check in notetsleep.
Originally, notetsleep required that it be called from g0 or with
preemption disabled (specifically from within the garbage collector).
CL 3660 made it require that it be called from g0 or that preemption
be *enabled*.
I'm not sure why it had the original exception for being called from a
user g within the garbage collector, but the current garbage collector
certainly doesn't need that, and the new condition is completely wrong.
Make the sanity check just require that it's called on g0.
Austin Clements [Sat, 2 Mar 2019 20:16:29 +0000 (15:16 -0500)]
sync: smooth out Pool behavior over GC with a victim cache
Currently, every Pool is cleared completely at the start of each GC.
This is a problem for heavy users of Pool because it causes an
allocation spike immediately after Pools are clear, which impacts both
throughput and latency.
This CL fixes this by introducing a victim cache mechanism. Instead of
clearing Pools, the victim cache is dropped and the primary cache is
moved to the victim cache. As a result, in steady-state, there are
(roughly) no new allocations, but if Pool usage drops, objects will
still be collected within two GCs (as opposed to one).
This victim cache approach also improves Pool's impact on GC dynamics.
The current approach causes all objects in Pools to be short lived.
However, if an application is in steady state and is just going to
repopulate its Pools, then these objects impact the live heap size *as
if* they were long lived. Since Pooled objects count as short lived
when computing the GC trigger and goal, but act as long lived objects
in the live heap, this causes GC to trigger too frequently. If Pooled
objects are a non-trivial portion of an application's heap, this
increases the CPU overhead of GC. The victim cache lets Pooled objects
affect the GC trigger and goal as long-lived objects.
This has no impact on Get/Put performance, but substantially reduces
the impact to the Pool user when a GC happens. PoolExpensiveNew
demonstrates this in the substantially reduction in the rate at which
the "New" function is called.
Austin Clements [Fri, 1 Mar 2019 20:33:33 +0000 (15:33 -0500)]
sync: use lock-free structure for Pool stealing
Currently, Pool stores each per-P shard's overflow in a slice
protected by a Mutex. In order to store to the overflow or steal from
another shard, a P must lock that shard's Mutex. This allows for
simple synchronization between Put and Get, but has unfortunate
consequences for clearing pools.
Pools are cleared during STW sweep termination, and hence rely on
pinning a goroutine to its P to synchronize between Get/Put and
clearing. This makes the Get/Put fast path extremely fast because it
can rely on quiescence-style coordination, which doesn't even require
atomic writes, much less locking.
The catch is that a goroutine cannot acquire a Mutex while pinned to
its P (as this could deadlock). Hence, it must drop the pin on the
slow path. But this means the slow path is not synchronized with
clearing. As a result,
1) It's difficult to reason about races between clearing and the slow
path. Furthermore, this reasoning often depends on unspecified nuances
of where preemption points can occur.
2) Clearing must zero out the pointer to every object in every Pool to
prevent a concurrent slow path from causing all objects to be
retained. Since this happens during STW, this has an O(# objects in
Pools) effect on STW time.
3) We can't implement a victim cache without making clearing even
slower.
This CL solves these problems by replacing the locked overflow slice
with a lock-free structure. This allows Gets and Puts to be pinned the
whole time they're manipulating the shards slice (Pool.local), which
eliminates the races between Get/Put and clearing. This, in turn,
eliminates the need to zero all object pointers, reducing clearing to
O(# of Pools) during STW.
In addition to significantly reducing STW impact, this also happens to
speed up the Get/Put fast-path and the slow path. It somewhat
increases the cost of PoolExpensiveNew, but we'll fix that in the next
CL.
Austin Clements [Fri, 8 Mar 2019 20:01:34 +0000 (15:01 -0500)]
sync: add Pool benchmarks to stress STW and reuse
This adds two benchmarks that will highlight two problems in Pool that
we're about to address.
The first benchmark measures the impact of large Pools on GC STW time.
Currently, STW time is O(# of items in Pools), and this benchmark
demonstrates 70µs STW times.
The second benchmark measures the impact of fully clearing all Pools
on each GC. Typically this is a problem in heavily-loaded systems
because it causes a spike in allocation. This benchmark stresses this
by simulating an expensive "New" function, so the cost of creating new
objects is reflected in the ns/op of the benchmark.
Austin Clements [Fri, 1 Mar 2019 19:54:00 +0000 (14:54 -0500)]
sync: internal dynamically sized lock-free queue for sync.Pool
This adds a dynamically sized, lock-free, single-producer,
multi-consumer queue that will be used in the new Pool stealing
implementation. It's built on top of the fixed-size queue added in the
previous CL.
Austin Clements [Fri, 1 Mar 2019 18:16:37 +0000 (13:16 -0500)]
sync: internal fixed size lock-free queue for sync.Pool
This is the first step toward fixing multiple issues with sync.Pool.
This adds a fixed size, lock-free, single-producer, multi-consumer
queue that will be used in the new Pool stealing implementation.
Jay Conrod [Wed, 9 Jan 2019 21:40:01 +0000 (16:40 -0500)]
cmd/go: parallelize package loading
load.PackageAndErrors now preloads data used to build load.Package
structures. Multiple packages may be preloaded in parallel, so this
parallelizes most of the package loading work.
The actual package construction and error-checking process is still
sequential, since this process needs to detect and report cycles.
Fixes #29758
Change-Id: Icf37e6669836ce8aad076e34fd895f97f4f3f9e2
Reviewed-on: https://go-review.googlesource.com/c/go/+/161397
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Bryan C. Mills <bcmills@google.com>
Austin Clements [Mon, 31 Dec 2018 00:47:27 +0000 (19:47 -0500)]
runtime: ring buffer for binary debug logging
This adds an internal runtime debug log. It uses per-M time-stamped
ring buffers of binary log records. On panic, these buffers are
collected, interleaved, and printed.
The entry-point to the debug log is a new "dlog" function. dlog is
designed so it can be used even from very constrained corners of the
runtime such as signal handlers or inside the write barrier.
The facility is only enabled if the debuglog build tag is set.
Otherwise, it compiles away to a no-op implementation.
The debug log format is also designed so it would be reasonable to
decode from a core dump, though this hasn't been implemented.
grant [Wed, 3 Apr 2019 14:21:21 +0000 (14:21 +0000)]
net: use libSystem bindings for DNS resolution on macos if cgo is unavailable
This change adds directives to link the res_search function in libSystem.
The corresponding Go function is then used in `lookup_darwin.go` for
resolution when cgo is disabled. This makes DNS resolution logic more
reliable as macOS has some unique quirks such as the `/etc/resolver/`
directory for specifying nameservers.
Than McIntosh [Thu, 4 Apr 2019 15:01:22 +0000 (11:01 -0400)]
math/bits: add gccgo-friendly code for compiler bootstrap
When building as part of the bootstrap process, avoid
use of "go:linkname" applied to variables, since this
feature is ill-defined/unsupported for gccgo.
Updates #30771.
Change-Id: Id44d01b5c98d292702e5075674117518cb59e2d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/170737 Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Richard Musiol [Sun, 24 Mar 2019 11:14:27 +0000 (12:14 +0100)]
cmd/compile: add saturating conversions on wasm
This change adds the GOWASM option "satconv" to enable the generation
of experimental saturating (non-trapping) float-to-int conversions.
It improves the performance of the conversion by 42%.
Previously the conversions had already been augmented with helper
functions to have saturating behavior. Now Wasm.rules is always using
the new operation names and wasm/ssa.go is falling back to the helpers
if the feature is not enabled.
The feature is in phase 4 of the WebAssembly proposal process:
https://github.com/WebAssembly/meetings/blob/master/process/phases.md
More information on the feature can be found at:
https://github.com/WebAssembly/nontrapping-float-to-int-conversions/blob/master/proposals/nontrapping-float-to-int-conversion/Overview.md
Robert Griesemer [Thu, 28 Mar 2019 20:32:31 +0000 (13:32 -0700)]
cmd/compile: better recovery after := (rather than =) in declarations
Before this fix, a mistaken := in a (const/type/var) declaration
ended that declaration with an error from which the parser didn't
recover well. This low-cost change will provide a better error
message and lets the parser recover perfectly.
Fixes #31092.
Change-Id: Ic4f94dc5e29dd00b7ef6d53a80dded638e3cea80
Reviewed-on: https://go-review.googlesource.com/c/go/+/169958 Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Keith Randall [Wed, 20 Mar 2019 17:47:17 +0000 (10:47 -0700)]
syscall: avoid _getdirentries64 on darwin
Getdirentries is implemented with the __getdirentries64 function
in libSystem.dylib. That function works, but it's on Apple's
can't-be-used-in-an-app-store-application list.
Implement Getdirentries using the underlying fdopendir/readdir_r/closedir.
The simulation isn't faithful, and could be slow, but it should handle
common cases.
Don't use Getdirentries in the stdlib, use fdopendir/readdir_r/closedir
instead (via (*os.File).readdirnames).
smasher164 [Thu, 7 Feb 2019 08:38:21 +0000 (03:38 -0500)]
cmd/compile: return assignment mismatch error in var declarations
Some var declarations return "extra expression" or "missing expression"
errors when they should return “assignment mismatch” instead. Change
the returned error messages to exhibit the desired behavior.
Fixes #30085.
Change-Id: I7189355fbb0f976d70100779db4f81a9ae64fb11
Reviewed-on: https://go-review.googlesource.com/c/go/+/161558 Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Bryan C. Mills [Tue, 8 Jan 2019 15:34:16 +0000 (10:34 -0500)]
cmd/go/internal/web: reject insecure redirects from secure origins
We rely on SSL certificates to verify the identity of origin servers.
If an HTTPS server redirects through a plain-HTTP URL, that hop can be
compromised. We should allow it only if the user set the -insecure
flag explicitly.
Jay Conrod [Mon, 11 Mar 2019 22:53:08 +0000 (18:53 -0400)]
cmd/go: print require chains in build list errors
mvs.BuildList and functions that invoke it directly (UpgradeAll) now
return an *mvs.BuildListError when there is an error retrieving the
requirements for a module. This new error prints the chain of
requirements from the main module to the module where the error
occurred.
These errors come up most commonly when a go.mod file has an
unexpected module path or can't be parsed for some other reason. It's
currently difficult to debug these errors because it's not clear where
the "bad" module is required from. Tools like "go list -m" and
"go mod why" don't work without the build graph.
Fixes #30661
Change-Id: I3c9d4683dcd9a5d7c259e5e4cc7e1ee209700b10
Reviewed-on: https://go-review.googlesource.com/c/go/+/166984
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Bryan C. Mills <bcmills@google.com>
cmd/go/internal/lockedfile: add a sync.Mutex to lockedfile.Mutex
The compiler (and race detector) don't interpret locking a file as a
synchronization operation, so we add an explicit (and redundant)
sync.Mutex to make that property clear.
The additional synchronization makes it safe to parallelize the tests
in cmd/go/internal/modfetch/coderepo_test.go, which cuts the wall time
of that test by around 50%.
Updates #30550
Change-Id: Ief3479020ebf9e0fee524a4aae5568697727c683
Reviewed-on: https://go-review.googlesource.com/c/go/+/170597
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Daniel Martí <mvdan@mvdan.cc> Reviewed-by: Jay Conrod <jayconrod@google.com>
cmd/go: add a note in help buildmode for c-archive on AIX
As ld on AIX doesn't keep the same layout in .text section,
-Wl,-bnoobjreoder must be passed to gcc when building a C program with a
Go archive.
Change-Id: I89b584cce43ab5792f315192b073923c10d5690e
Reviewed-on: https://go-review.googlesource.com/c/go/+/170538
Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Daniel Martí [Fri, 23 Nov 2018 16:56:23 +0000 (16:56 +0000)]
encoding/json: speed up tokenization of literals
Decoder.Decode and Unmarshal actually scan the input bytes twice - the
first time to check for syntax errors and the length of the value, and
the second to perform the decoding.
It's in the second scan that we actually tokenize the bytes. Since
syntax errors aren't a possibility, we can take shortcuts.
In particular, literals such as quoted strings are very common in JSON,
so we can avoid a lot of work by special casing them.
cmd/go/internal/modload: fix aliasing bug in (*mvsReqs).Required with -mod=vendor
(*mvsReqs).Required assumes that it is safe to mutate the slice
returned by (*mvsReqs).required. In most cases, that was true, but in
the case of -mod=vendor it resulted in unsynchronized (and
potentially interfering) writes to the global vendorList.
splittests already contains most of the tests that cover explode. Add
the missing ones and skip the append test for empty results which would
otherwise lead to an "index out of range" panic.
syscall: on AIX use nsendmsg and nrecvmsg, define SockaddrDatalink
This commit changes sendmsg, recvmsg to use nsendmsg, nrecvmsg on AIX.
These syscalls support the new msghdr structure (with Control
and Controllen) which is needed for golang.org/x/net.
Also define SockaddrDataLink.
Change-Id: I233fbd24f9eb86648e0d4d50c2b56da3626292d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/170537
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Agniva De Sarker [Mon, 7 Jan 2019 16:45:47 +0000 (22:15 +0530)]
image/jpeg: reduce bound checks from idct and fdct
Before -
$gotip build -gcflags="-d=ssa/check_bce/debug=1" fdct.go idct.go
./fdct.go:89:10: Found IsInBounds
./fdct.go:90:10: Found IsInBounds
./fdct.go:91:10: Found IsInBounds
./fdct.go:92:10: Found IsInBounds
./fdct.go:93:10: Found IsInBounds
./fdct.go:94:10: Found IsInBounds
./fdct.go:95:10: Found IsInBounds
./fdct.go:96:10: Found IsInBounds
./idct.go:77:9: Found IsInBounds
./idct.go:77:27: Found IsInBounds
./idct.go:77:45: Found IsInBounds
./idct.go:78:7: Found IsInBounds
./idct.go:78:25: Found IsInBounds
./idct.go:78:43: Found IsInBounds
./idct.go:78:61: Found IsInBounds
./idct.go:79:13: Found IsInBounds
./idct.go:92:13: Found IsInBounds
./idct.go:93:12: Found IsInBounds
./idct.go:94:12: Found IsInBounds
./idct.go:95:12: Found IsInBounds
./idct.go:97:12: Found IsInBounds
./idct.go:98:12: Found IsInBounds
./idct.go:99:12: Found IsInBounds
After -
$gotip build -gcflags="-d=ssa/check_bce/debug=1" fdct.go idct.go
./fdct.go:90:9: Found IsSliceInBounds
./idct.go:76:11: Found IsSliceInBounds
./idct.go:145:11: Found IsSliceInBounds
Ian Lance Taylor [Tue, 2 Apr 2019 22:05:33 +0000 (15:05 -0700)]
misc/cgo/testcarchive: skip TestSignalForwardingExternal on darwin/amd64
On darwin/amd64 the runtime method sigctxt.fixsigcode changes SIGSEGV
signals so that they are never marked SI_USER. CL 169120 changed the
signal handler to call fixsigcode even when the signal is delivered to
a non-Go thread. This breaks TestSignalForwardingExternal, so skip it.
Change-Id: I6740fb5a8f4f854ca69793537a983a696da3b495
Reviewed-on: https://go-review.googlesource.com/c/go/+/170446
Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Elias Naur [Tue, 2 Apr 2019 21:58:43 +0000 (23:58 +0200)]
runtime/cgo: look for android_get_device_api_level in libc.so
The presence of the android_get_device_api_level symbol is used to
detect Android Q or later. Use the suggestion by Ryan Prichard and
look for it in libc.so and not in the entire program where someone
else might have defined it.
Manually tested on an Android Q amd64 emulator and arm64 Pixel.
Package unsafe's safety rules require that pointers converted to
uintptr must be converted back to pointer-type before being stored
into memory. In particular, storing a pointer into a non-pointer-typed
expression does not guarantee the pointer stays valid, even if the
expression refers to a pointer-typed variable.
wasm's StorepNoWB implementation violates these rules by storing a
pointer through a uintptr-typed expression.
This happens to work today because esc.go is lenient in its
implementation of package unsafe's rules, but my escape analysis
rewrite follows them more rigorously, which causes val to be treated
as a non-leaking parameter.
This CL fixes the issue by using a *T-typed expression, where T is
marked //go:notinheap so that the compiler still omits the write
barrier as appropriate.
The certificates argument to verifyServerCertificate must contain
at least one certificate. Simplify the intermediate certificate
handling code accordingly.
Matthew Dempsky [Mon, 1 Apr 2019 21:01:58 +0000 (14:01 -0700)]
cmd/compile: trim more unnecessary escape analysis messages
"leaking closure reference" is redundant for similar reasons as "&x
escapes to heap" for OADDR nodes: the reference itself does not
allocate, and we already report when the referenced variable is moved
to heap.
"mark escaped content" is redundant with "leaking param content".
Alessandro Arzilli [Mon, 25 Feb 2019 12:56:18 +0000 (13:56 +0100)]
compile,link: export package name in debug_info
Add a new custom attribute to compile units containing the package name
of the package (i.e. the name after the 'package' keyword), so that
debuggers can know it when it's different from the last segment
of the package path.
Matthew Dempsky [Mon, 1 Apr 2019 18:58:33 +0000 (11:58 -0700)]
cmd/compile: skip escape analysis diagnostics for OADDR
For most nodes (e.g., OPTRLIT, OMAKESLICE, OCONVIFACE), escape
analysis prints "escapes to heap" or "does not escape" to indicate
whether that node's allocation can be heap or stack allocated.
These messages are also emitted for OADDR, even though OADDR does not
actually allocate anything itself. Moreover, it's redundant because
escape analysis already prints "moved to heap" diagnostics when an
OADDR node like "&x" causes x to require heap allocation.
Because OADDR nodes don't allocate memory, my escape analysis rewrite
doesn't naturally emit the "escapes to heap" / "does not escape"
diagnostics for them. It's also non-trivial to replicate the exact
semantics esc.go uses for OADDR.
Since there are so many of these messages, I'm disabling them in this
CL by themselves. I modified esc.go to suppress the Warnl calls
without any other behavior changes, and then used a shell script to
automatically remove any ERROR messages mentioned by run.go in
"missing error" or "no match for" lines.
Fixes #16300.
Updates #23109.
Change-Id: I3993e2743c3ff83ccd0893f4e73b366ff8871a57
Reviewed-on: https://go-review.googlesource.com/c/go/+/170319
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com> Reviewed-by: David Chase <drchase@google.com>
Mark Ryan [Mon, 18 Mar 2019 14:48:34 +0000 (15:48 +0100)]
cmd/asm: Fix EVEX RIP-relative addressing
AVX-512 instructions that use RIP-relative addressing and require the
R bit of the EVEX prefix to be zero, i.e., instructions that use Z8-Z15 or
Z24-Z31, are incorrectly encoded by the assembler. The reason is that
the location of the offset at which the relative address is to be written
is incorrectly computed when the R bit is clear.
For example,
VMOVUPS bInitX<>+0(SB), Z0
encodes correctly to
62 f1 7c 48 10 05 66 e9 02 00
whereas
VMOVUPS bInitX<>+0(SB), Z8
encodes incorrectly to
62 71 7c 48 10 05 00 56 e9 02 00
Note the extra zero byte between the ModR/M byte (05) and the relative
address starting with 56. This error results in the first byte of the
following instruction being overwritten and typically, a program crash.
This commit fixes the issue in the same way that is fixed for VEX encoded
instructions, by simply not incrementing the offset for EVEX instructions.
Existing test code created for a similar VEX encoding issue (19518) has
been modified to also test for the issue addressed by this commit.