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Commit Graph

28504 Commits

Author SHA1 Message Date
Joe Tsai
c52dff0727 doc/go1.7.html: make RFC an actual link
Change-Id: I5e8dad0c2534b5c3654cf0a0b51a38186d627a3c
Reviewed-on: https://go-review.googlesource.com/23582
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-05-31 21:17:23 +00:00
Ian Lance Taylor
2256e38978 runtime: update pprof binary header URL
The code has moved from code.google.com to github.com.

Change-Id: I0cc9eb69b3fedc9e916417bc7695759632f2391f
Reviewed-on: https://go-review.googlesource.com/23523
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2016-05-31 21:10:20 +00:00
Michael Hudson-Doyle
2c1791b13b cmd/link: suppress PIE whenever externally linking with a sanitizer
golang.org/issue/15443 complained that a race-enabled PIE binary crashed at
startup, but other ways of linking in tsan (or other sanitizers) such as

 #cgo CFLAGS: -fsanitize=thread
 #cgo LDFLAGS: -fsanitize=thread

have the same problem. Pass -no-pie to the host linker (if supported) if any
-fsanitizer=foo cgo LDFLAG is seen when linking.

Fixes #15887

Change-Id: Id799770f8d045f6f40fa8c463563937a5748d1a8
Reviewed-on: https://go-review.googlesource.com/23535
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-05-31 20:57:57 +00:00
Michael Hudson-Doyle
2a6544b604 cmd/go, cmd/link: set LC_ALL=C when checking if host compiler supports -no-pie
Fixes #15900

Change-Id: Ieada5f4e3b3b2ae358414e013f3090b4b820569b
Reviewed-on: https://go-review.googlesource.com/23536
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-05-31 20:57:21 +00:00
Ian Lance Taylor
66736880ca runtime/cgo: add TSAN acquire/release calls
Add TSAN acquire/release calls to runtime/cgo to match the ones
generated by cgo.  This avoids a false positive race around the malloc
memory used in runtime/cgo when other goroutines are simultaneously
calling malloc and free from cgo.

These new calls will only be used when building with CGO_CFLAGS and
CGO_LDFLAGS set to -fsanitize=thread, which becomes a requirement to
avoid all false positives when using TSAN.  These are needed not just
for runtime/cgo, but also for any runtime package that uses cgo (such as
net and os/user).

Add an unused attribute to the _cgo_tsan_acquire and _cgo_tsan_release
functions, in case there are no actual cgo function calls.

Add a test that checks that setting CGO_CFLAGS/CGO_LDFLAGS avoids a
false positive report when using os/user.

Change-Id: I0905c644ff7f003b6718aac782393fa219514c48
Reviewed-on: https://go-review.googlesource.com/23492
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
2016-05-31 20:53:16 +00:00
Josh Bleecher Snyder
0e13dbc1a9 cmd/compile: disallow multiple nil cases in a type switch
Fixes #15898.

Change-Id: I66e2ad21f283563c7142aa820f0354711d964768
Reviewed-on: https://go-review.googlesource.com/23573
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
2016-05-31 20:31:00 +00:00
Joe Tsai
7cd6cae6a6 compress/flate: use seperate const block for exported constants
As rendered on https://tip.golang.org/pkg/compress/flate/, there is an
extra new-line because of the unexported constants in the same block.

<<<
const (
    NoCompression      = 0
    BestSpeed          = 1
    BestCompression    = 9
    DefaultCompression = -1
    HuffmanOnly        = -2 // Disables match search and only does Huffman entropy reduction.

)
>>>

Instead, seperate the exported compression level constants into its own
const block. This is both more readable and also fixes the issue.

Change-Id: I60b7966c83fb53356c02e4640d05f55a3bee35b7
Reviewed-on: https://go-review.googlesource.com/23557
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-31 18:28:44 +00:00
Ian Lance Taylor
4223294eab runtime/pprof, cmd/pprof: fix profiling for PIE
In order to support pprof for position independent executables, pprof
needs to adjust the PC addresses stored in the profile by the address at
which the program is loaded. The legacy profiling support which we use
already supports recording the GNU/Linux /proc/self/maps data
immediately after the CPU samples, so do that. Also change the pprof
symbolizer to use the information, if available, when looking up
addresses in the Go pcline data.

Fixes #15714.

Change-Id: I4bf679210ef7c51d85cf873c968ce82db8898e3e
Reviewed-on: https://go-review.googlesource.com/23525
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
2016-05-31 13:02:09 +00:00
Andrew Gerrand
87ee12cece crypto/tls: reduce size of buffer in throughput benchmarks
The Windows builders run the throughput benchmarks really slowly with a
64kb buffer. Lowering it to 16kb brings the performance back into line
with the other builders.

This is a work-around to get the build green until we can figure out why
the Windows builders are slow with the larger buffer size.

Update #15899

Change-Id: I215ebf115e8295295c87f3b3e22a4ef1f9e77f81
Reviewed-on: https://go-review.googlesource.com/23574
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-05-31 05:40:37 +00:00
Richard Miller
8e6e9e8381 syscall: plan9 - mark gbit16 as go:nosplit
This is a correction to CL 22610.  The gbit16 function is called in
StartProcess between fork and exec, and therefore must not split the
stack.  Normally it's inlined so this is not an issue, but on one
occasion I've observed it to be compiled without inlining, and the
result was a panic.  Mark it go:nosplit to be safe.

Change-Id: I0381754397b766431bf406d9767c73598d23b901
Reviewed-on: https://go-review.googlesource.com/23560
Reviewed-by: David du Colombier <0intro@gmail.com>
Run-TryBot: David du Colombier <0intro@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-05-31 04:53:19 +00:00
Andrew Gerrand
b3f98d7a42 sync: document that RWMutex read locks may not be held recursively
Fixes #15418

Change-Id: Ibc51d602eb28819d0e44e5ca13a5c61573e4111c
Reviewed-on: https://go-review.googlesource.com/23570
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
2016-05-31 00:22:56 +00:00
Josh Bleecher Snyder
d2c92f8453 path/filepath: prevent infinite recursion on Windows on UNC input
This is a minimal fix to prevent this and
other possible future infinite recursion.
We can put in a proper fix for UNC in Go 1.8.

Updates #15879

Change-Id: I3653cf5891bab8511adf66fa3c1a1d8912d1a293
Reviewed-on: https://go-review.googlesource.com/23572
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-05-31 00:11:32 +00:00
Andrew Gerrand
81a8f1a794 doc: remove remnant mention of io.SizedReaderAt from Go 1.7 docs
Updates #15810

Change-Id: I37f14a0ed1f5ac24ea2169a7e65c0469bfddd928
Reviewed-on: https://go-review.googlesource.com/23559
Reviewed-by: Michael McGreevy <mcgreevy@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-05-30 05:24:16 +00:00
Mikio Hara
dc5b5239e8 net: don't call forceCloseSockets in non-TestMain functions
forceCloseSockets is just designed as a kingston valve for TestMain
function and is not suitable to keep track of inflight sockets.

Fixes #15525.

Change-Id: Id967fe5b8da99bb08b699cc45e07bbc3dfc3ae3d
Reviewed-on: https://go-review.googlesource.com/23505
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-30 03:30:14 +00:00
Augusto Roman
4e01c132d0 doc: correct release notes for non-string map keys in encoding/json
The original draft mentioned support for json.Marshaler, but that's
not the case.  JSON supports only string keys (not arbitrary JSON)
so only encoding.TextMarshaller is supported.

Change-Id: I7788fc23ac357da88e92aa0ca17b513260840cee
Reviewed-on: https://go-review.googlesource.com/23529
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-05-30 01:09:51 +00:00
Keith Randall
1739657513 cmd/compile: shift tests, fix triple-shift rules
Add a bunch of tests for shifts.

Fix triple-shift rules to always take constant shifts as 64 bits.
(Earlier rules always promote shift amounts to 64 bits.)
Add overflow checks.

Increases generic rule coverage to 91%

Change-Id: I6b42d368d19d36ac482dbb8e0d4f67e30ad7145d
Reviewed-on: https://go-review.googlesource.com/23555
Reviewed-by: Todd Neal <todd@tneal.org>
2016-05-29 20:36:21 +00:00
Keith Randall
79f7ccf2c3 cmd/compile: add constant fold comparison tests
Increases generic.rules coverage from 91% to 95%.

Change-Id: I981eb94f3cd10d2f87c836576a43786787a25d83
Reviewed-on: https://go-review.googlesource.com/23556
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Todd Neal <todd@tneal.org>
2016-05-29 20:23:55 +00:00
Joe Tsai
b859a78e0a io: use SeekStart, SeekCurrent, and SeekEnd in io.Seeker documentation
The documentation previously used C style enumerations: 0, 1, 2.
While this is pretty much universally correct, it does not help a user
become aware of the existence of the SeekStart, SeekCurrent, and SeekEnd
constants. Thus, we should use them in the documentation to direct people's
attention to them.

Updates #6885

Change-Id: I44b5e78d41601c68a0a1c96428c853df53981d52
Reviewed-on: https://go-review.googlesource.com/23551
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-05-29 06:52:45 +00:00
Joe Tsai
4969b46a31 doc/go1.7.html: update documentation regarding compress/flate
Document the following:
* That the algorithmic changes are still compliant with RFC 1951. I remember
people having questions regarding this issue, and it would be good to re-assure
them that it is still standards compliant.
* io.EOF can now be returned early (c27efce66b)
* Use the term "decompress" when referred to as an action. The term "uncompressed"
or "decompressed" are both valid as ways to represent the current state of the data.

Change-Id: Ie29ebce709357359e7c36d3e7f3d53b260eaadfa
Reviewed-on: https://go-review.googlesource.com/23552
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-05-29 06:52:39 +00:00
Emmanuel Odeke
24996832c6 net/http/httputil: fix typos in deprecation comments
Fixes #15868

Change-Id: I4e4471e77091309c4ea1d546b2c4f20dfbb4314e
Reviewed-on: https://go-review.googlesource.com/23550
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-05-28 23:44:32 +00:00
Robert Griesemer
795809b5c7 go/types: better debugging output for init order computation
Also: Added some test cases for issue #10709.
No impact when debugging output is disabled (default).

For #10709.

Change-Id: I0751befb222c86d46225377a674f6bad2990349e
Reviewed-on: https://go-review.googlesource.com/23442
Reviewed-by: Alan Donovan <adonovan@google.com>
2016-05-27 23:39:38 +00:00
Ilya Tocar
429bbf3312 strings: fix and reenable amd64 Index for 17-31 byte strings
Fixes #15689

Change-Id: I56d0103738cc35cd5bc5e77a0e0341c0dd55530e
Reviewed-on: https://go-review.googlesource.com/23440
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Nigel Tao <nigeltao@golang.org>
2016-05-27 22:57:32 +00:00
Keith Randall
42da35c699 cmd/compile: SSA, don't let write barrier clobber return values
When we do *p = f(), we might need to copy the return value from
f to p with a write barrier.  The write barrier itself is a call,
so we need to copy the return value of f to a temporary location
before we call the write barrier function.  Otherwise, the call
itself (specifically, marshalling the args to typedmemmove) will
clobber the value we're trying to write.

Fixes #15854

Change-Id: I5703da87634d91a9884e3ec098d7b3af713462e7
Reviewed-on: https://go-review.googlesource.com/23522
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-27 22:11:45 +00:00
Russ Cox
3a6a41868e doc: mention frame pointers in Go 1.7 release notes
For #15840.

Change-Id: I2ecf5c7b00afc2034cf3d7a1fd78636a908beb67
Reviewed-on: https://go-review.googlesource.com/23517
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2016-05-27 20:32:25 +00:00
Austin Clements
496cf215cf crypto/tls: gofmt
Commit fa3543e introduced formatting errors.

Change-Id: I4b921f391a9b463cefca4318ad63b70ae6ce6865
Reviewed-on: https://go-review.googlesource.com/23514
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
2016-05-27 19:11:48 +00:00
Austin Clements
e149624ebb cmd/compile/internal/gc: gofmt
Commit 36a80c5 introduced formatting errors.

Change-Id: I6d5b231200cd7abcd5b94c1a3f4e99f10ee11c4f
Reviewed-on: https://go-review.googlesource.com/23513
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
2016-05-27 19:08:39 +00:00
Mikio Hara
53af0d3476 crypto/tls: fix race in Benchmark{Throughput,Latency}
Fixes #15864.

Change-Id: Ic12aa3654bf0b7e4a26df20ea92d07d7efe7339c
Reviewed-on: https://go-review.googlesource.com/23504
Reviewed-by: David Chase <drchase@google.com>
2016-05-27 19:05:38 +00:00
Mikio Hara
b0b2f7d6dd net/http/httptrace: fix nit in test
Change-Id: I6dc3666398b4cd7a7195bb9c0e321fa8b733fa15
Reviewed-on: https://go-review.googlesource.com/23502
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-27 18:47:40 +00:00
Mikio Hara
c340f4867b runtime: skip TestGdbBacktrace on netbsd
Also adds missing copyright notice.

Updates #15603.

Change-Id: Icf4bb45ba5edec891491fe5f0039a8a25125d168
Reviewed-on: https://go-review.googlesource.com/23501
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-27 18:47:08 +00:00
Austin Clements
6a86dbe75f runtime: always call stackfree on the system stack
Currently when the garbage collector frees stacks of dead goroutines
in markrootFreeGStacks, it calls stackfree on a regular user stack.
This is a problem, since stackfree manipulates the stack cache in the
per-P mcache, so if it grows the stack or gets preempted in the middle
of manipulating the stack cache (which are both possible since it's on
a user stack), it can easily corrupt the stack cache.

Fix this by calling markrootFreeGStacks on the system stack, so that
all calls to stackfree happen on the system stack. To prevent this bug
in the future, mark stack functions that manipulate the mcache as
go:systemstack.

Fixes #15853.

Change-Id: Ic0d1c181efb342f134285a152560c3a074f14a3d
Reviewed-on: https://go-review.googlesource.com/23511
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-27 17:53:21 +00:00
Austin Clements
966baedfea runtime: record Python stack on TestGdbPython failure
For #15599.

Change-Id: Icc2e58a3f314b7a098d78fe164ba36f5b2897de6
Reviewed-on: https://go-review.googlesource.com/23481
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-05-27 16:46:05 +00:00
Russ Cox
fa3543e337 crypto/tls: adjust dynamic record sizes to grow arithmetically
The current code, introduced after Go 1.6 to improve latency on
low-bandwidth connections, sends 1 kB packets until 1 MB has been sent,
and then sends 16 kB packets (the maximum record size).

Unfortunately this decreases throughput for 1-16 MB responses by 20% or so.

Following discussion on #15713, change cutoff to 128 kB sent
and also grow the size allowed for successive packets:
1 kB, 2 kB, 3 kB, ..., 15 kB, 16 kB.
This fixes the throughput problems: the overhead is now closer to 2%.

I hope this still helps with latency but I don't have a great way to test it.
At the least, it's not worse than Go 1.6.

Comparing MaxPacket vs DynamicPacket benchmarks:

name              maxpkt time/op  dyn. time/op delta
Throughput/1MB-8    5.07ms ± 7%   5.21ms ± 7%  +2.73%  (p=0.023 n=16+16)
Throughput/2MB-8   15.7ms ±201%    8.4ms ± 5%    ~     (p=0.604 n=20+16)
Throughput/4MB-8    14.3ms ± 1%   14.5ms ± 1%  +1.53%  (p=0.000 n=16+16)
Throughput/8MB-8    26.6ms ± 1%   26.8ms ± 1%  +0.47%  (p=0.003 n=19+18)
Throughput/16MB-8   51.0ms ± 1%   51.3ms ± 1%  +0.47%  (p=0.000 n=20+20)
Throughput/32MB-8    100ms ± 1%    100ms ± 1%  +0.24%  (p=0.033 n=20+20)
Throughput/64MB-8    197ms ± 0%    198ms ± 0%  +0.56%   (p=0.000 n=18+7)

The small MB runs are bimodal in both cases, probably GC pauses.
But there's clearly no general slowdown anymore.

Fixes #15713.

Change-Id: I5fc44680ba71812d24baac142bceee0e23f2e382
Reviewed-on: https://go-review.googlesource.com/23487
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-05-27 16:34:57 +00:00
Russ Cox
52c2db7e6d doc/go1.7.html: fix broken sentence
Change-Id: Ia540c890767dcb001d3b3b55d98d9517b13b21da
Reviewed-on: https://go-review.googlesource.com/23510
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-05-27 16:33:59 +00:00
Russ Cox
605e751b53 net/http: change Transport.Dialer to Transport.DialContext
New in Go 1.7 so still possible to change.
This allows implementations not tied to *net.Dialer.

Fixes #15748.

Change-Id: I5fabbf13c7f1951c06587a4ccd120def488267ce
Reviewed-on: https://go-review.googlesource.com/23489
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-05-27 16:26:42 +00:00
Russ Cox
36a80c5941 cmd/compile: clean up, document Node closure fields
Requested during CL 23431.

Change-Id: I513ae42166b3a9fcfe51231ff55c163ab672e7d2
Reviewed-on: https://go-review.googlesource.com/23485
Reviewed-by: David Chase <drchase@google.com>
2016-05-27 15:33:10 +00:00
Russ Cox
93369001c7 cmd/compile: delete Func.Outer
This was just storage for a linked list.

Change-Id: I850e8db1e1f5e72410f5c904be9409179b56a94a
Reviewed-on: https://go-review.googlesource.com/23484
Reviewed-by: David Chase <drchase@google.com>
2016-05-27 15:33:01 +00:00
Russ Cox
cedc7c8f20 doc/go1.7.html: incorporate Rob's comments from CL 23379
For #15810.

Change-Id: Ib529808f664392feb9b36770f3d3d875fcb54528
Reviewed-on: https://go-review.googlesource.com/23488
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-27 15:28:51 +00:00
Emmanuel Odeke
65dd08197e doc/go1.7: document signal name printing during panics
Document new behavior about signal name printing
in panics as per CL golang.org/cl/22753.

For #15810

Change-Id: I9c677d5dd779b41e82afa25e3c797d8e739600d3
Reviewed-on: https://go-review.googlesource.com/23493
Reviewed-by: Russ Cox <rsc@golang.org>
2016-05-27 14:50:42 +00:00
Russ Cox
dec1bae916 cmd/compile: additional paranoia and checking in plive.go
The main check here is that liveness now crashes if it finds an instruction
using a variable that should be tracked but is not.

Comments and adjustments in nodarg to explain what's going on and
to remove the "-1" argument added a few months ago, plus a sketch
of a future simplification.

The need for n.Orig in the earlier CL seems to have been an intermediate
problem rather than fundamental: the new explanations in nodarg make
clear that nodarg is not causing the problem I thought, and in fact now
using n instead of n.Orig works fine in plive.go.

Change-Id: I3f5cf9f6e4438a6d27abac7d490e7521545cd552
Reviewed-on: https://go-review.googlesource.com/23450
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-05-27 14:13:11 +00:00
Dmitri Shuralyov
e9228dd949 cmd/go: fixup for parsing SCP-like addresses
This is a fixup change for commit 5cd2944803
that added parsing of SCP-like addresses. To get the expected output
from (*url.URL).String(), Path needs to be set, not RawPath.

Add a test for this, since it has already regressed multiple times.

Updates #11457.

Change-Id: I806f5abbd3cf65e5bdcef01aab872caa8a5b8891
Reviewed-on: https://go-review.googlesource.com/23447
Run-TryBot: Andrew Gerrand <adg@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-05-27 06:28:40 +00:00
Russ Cox
20803b845f cmd/compile: eliminate PPARAMREF
As in the elimination of PHEAP|PPARAM in CL 23393,
this is something the front end can trivially take care of
and then not bother the back ends with.
It also eliminates some suspect (and only lightly exercised)
code paths in the back ends.

I don't have a smoking gun for this one but it seems
more clearly correct.

Change-Id: I3b3f5e669b3b81d091ff1e2fb13226a6f14c69d5
Reviewed-on: https://go-review.googlesource.com/23431
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
2016-05-27 05:16:16 +00:00
Russ Cox
b6dc3e6f66 cmd/compile: fix liveness computation for heap-escaped parameters
The liveness computation of parameters generally was never
correct, but forcing all parameters to be live throughout the
function covered up that problem. The new SSA back end is
too clever: even though it currently keeps the parameter values live
throughout the function, it may find optimizations that mean
the current values are not written back to the original parameter
stack slots immediately or ever (for example if a parameter is set
to nil, SSA constant propagation may replace all later uses of the
parameter with a constant nil, eliminating the need to write the nil
value back to the stack slot), so the liveness code must now
track the actual operations on the stack slots, exposing these
problems.

One small problem in the handling of arguments is that nodarg
can return ONAME PPARAM nodes with adjusted offsets, so that
there are actually multiple *Node pointers for the same parameter
in the instruction stream. This might be possible to correct, but
not in this CL. For now, we fix this by using n.Orig instead of n
when considering PPARAM and PPARAMOUT nodes.

The major problem in the handling of arguments is general
confusion in the liveness code about the meaning of PPARAM|PHEAP
and PPARAMOUT|PHEAP nodes, especially as contrasted with PAUTO|PHEAP.
The difference between these two is that when a local variable "moves"
to the heap, it's really just allocated there to start with; in contrast,
when an argument moves to the heap, the actual data has to be copied
there from the stack at the beginning of the function, and when a
result "moves" to the heap the value in the heap has to be copied
back to the stack when the function returns
This general confusion is also present in the SSA back end.

The PHEAP bit worked decently when I first introduced it 7 years ago (!)
in 391425ae. The back end did nothing sophisticated, and in particular
there was no analysis at all: no escape analysis, no liveness analysis,
and certainly no SSA back end. But the complications caused in the
various downstream consumers suggest that this should be a detail
kept mainly in the front end.

This CL therefore eliminates both the PHEAP bit and even the idea of
"heap variables" from the back ends.

First, it replaces the PPARAM|PHEAP, PPARAMOUT|PHEAP, and PAUTO|PHEAP
variable classes with the single PAUTOHEAP, a pseudo-class indicating
a variable maintained on the heap and available by indirecting a
local variable kept on the stack (a plain PAUTO).

Second, walkexpr replaces all references to PAUTOHEAP variables
with indirections of the corresponding PAUTO variable.
The back ends and the liveness code now just see plain indirected
variables. This may actually produce better code, but the real goal
here is to eliminate these little-used and somewhat suspect code
paths in the back end analyses.

The OPARAM node type goes away too.

A followup CL will do the same to PPARAMREF. I'm not sure that
the back ends (SSA in particular) are handling those right either,
and with the framework established in this CL that change is trivial
and the result clearly more correct.

Fixes #15747.

Change-Id: I2770b1ce3cbc93981bfc7166be66a9da12013d74
Reviewed-on: https://go-review.googlesource.com/23393
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-27 03:19:52 +00:00
Alex Brainman
99d29d5a43 path/filepath: fix globbing of c:\*dir\... pattern
The problem was introduced by the recent filepath.Join change.

Fixes #14949

Change-Id: I7ee52f210e12bbb1369e308e584ddb2c7766e095
Reviewed-on: https://go-review.googlesource.com/23240
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2016-05-27 01:55:31 +00:00
Ian Lance Taylor
b5d18b50ac cmd/cgo: remove -O options when generating compiler errors
The cgo tool generates compiler errors to find out what kind of name it
is using.  Turning on optimization can confuse that process by producing
new unexpected messages.

Fixes #14669.

Change-Id: Idc8e35fd259711ecc9638566b691c11d17140325
Reviewed-on: https://go-review.googlesource.com/23231
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2016-05-27 01:40:30 +00:00
Keith Randall
9369f22b84 cmd/compile: testing harness for checking generated assembly
Add a test which compiles a function and checks the
generated assembly to make sure certain patterns are present.
This test allows us to do white box tests of the compiler
to make sure optimizations don't regress.

Added a few simple tests for now.  More to come.

Change-Id: I4ab5ce5d95b9e04e7d0d9328ffae47b8d1f95e74
Reviewed-on: https://go-review.googlesource.com/23403
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-26 23:07:01 +00:00
Quentin Smith
b1894bb5cc encoding/json: improve Decode example
Decoding a JSON message does not touch unspecified or null fields;
always use a new underlying struct to prevent old field values from
sticking around.

Fixes: #14640

Change-Id: Ica78c208ce104e2cdee1d4e92bf58596ea5587c8
Reviewed-on: https://go-review.googlesource.com/23483
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-05-26 22:40:14 +00:00
Keith Randall
02bf6b5ef9 cmd/compile: add tests for logical simplification rewrite rules
Increases coverage of generic.rules from 72% to 84%.

Change-Id: I1b139aeeb6410d025d49cbe4e4601f6f935ce1e5
Reviewed-on: https://go-review.googlesource.com/23490
Reviewed-by: Todd Neal <todd@tneal.org>
2016-05-26 22:16:52 +00:00
Keith Randall
0e930015c1 cmd/compile: log rules to a file for rule coverage tool
When rules are generated with -log, log rule application to a file.

The file is opened in append mode so multiple calls to the compiler
union their logs.

Change-Id: Ib35c7c85bf58e5909ea9231043f8cbaa6bf278b7
Reviewed-on: https://go-review.googlesource.com/23406
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-05-26 20:37:05 +00:00
Josh Bleecher Snyder
13a5b1faee cmd/compile: improve domorder documentation
domorder has some non-obvious useful properties
that we’re relying on in cse.
Document them and provide an argument that they hold.
While we’re here, do some minor renaming.

The argument is a re-working of a private email
exchange with Todd Neal and David Chase.

Change-Id: Ie154e0521bde642f5f11e67fc542c5eb938258be
Reviewed-on: https://go-review.googlesource.com/23449
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-05-26 20:01:24 +00:00
Marcel van Lohuizen
2deb9209de math/big: using Run for some more benchmarks
Change-Id: I3ede8098f405de5d88e51c8370d3b68446d40744
Reviewed-on: https://go-review.googlesource.com/23428
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2016-05-26 19:14:13 +00:00