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Commit Graph

40124 Commits

Author SHA1 Message Date
Brian Kessler
68819fb6d2 cmd/compile: add signed divisibility by power of 2 rules
For powers of two (c=1<<k), the divisibility check x%c == 0 can be made
just by checking the trailing zeroes via a mask x&(c-1)==0 even for signed
integers.  This avoids division fixups when just divisibility check is needed.

To apply this rule the generic divisibility rule for  A%B = A-(A/B*B) is disabled
on the "opt" pass, but this does not affect generated code as this rule is applied
later.

The speed up on amd64 due to elimination of unneccessary fixup code is ~55%:

name                     old time/op  new time/op  delta
DivconstI64-4            2.08ns ± 0%  2.07ns ± 0%     ~     (p=0.079 n=5+5)
DivisiblePow2constI64-4  1.78ns ± 1%  0.81ns ± 1%  -54.55%  (p=0.008 n=5+5)
DivconstU64-4            2.08ns ± 0%  2.08ns ± 0%     ~     (p=1.000 n=5+5)
DivconstI32-4            1.53ns ± 0%  1.53ns ± 0%     ~     (all equal)
DivisiblePow2constI32-4  1.79ns ± 1%  0.81ns ± 4%  -54.75%  (p=0.008 n=5+5)
DivconstU32-4            1.78ns ± 1%  1.78ns ± 1%     ~     (p=1.000 n=5+5)
DivconstI16-4            1.54ns ± 2%  1.53ns ± 0%     ~     (p=0.333 n=5+4)
DivisiblePow2constI16-4  1.78ns ± 0%  0.79ns ± 1%  -55.39%  (p=0.000 n=4+5)
DivconstU16-4            1.00ns ± 5%  0.99ns ± 1%     ~     (p=0.730 n=5+5)
DivconstI8-4             1.54ns ± 0%  1.53ns ± 0%     ~     (p=0.714 n=4+5)
DivisiblePow2constI8-4   1.78ns ± 0%  0.80ns ± 0%  -55.06%  (p=0.000 n=5+4)
DivconstU8-4             0.93ns ± 1%  0.95ns ± 1%   +1.72%  (p=0.024 n=5+5)

A follow-up CL will address the general case of x%c == 0 for signed integers.

Updates #15806

Change-Id: I0d284863774b1bc8c4ce87443bbaec6103e14ef4
Reviewed-on: https://go-review.googlesource.com/c/go/+/168038
Reviewed-by: Keith Randall <khr@golang.org>
2019-04-23 20:35:54 +00:00
Keith Randall
8515d9cf65 runtime: randomize package initialization order in race mode
This is one small step to force people to not depend on the order of
initialization of packages which are not explicitly ordered by import
directives. Similar to randomizing map iteration order, this makes
sure people aren't depending on the behavior of the current release,
so that we can change the order in future releases without breaking
everyone.

Maybe one day we can randomize always, but for now we do it just in
race mode. (We would need to measure the impact on startup time before
we enabled it always.)

RELNOTE=yes

Change-Id: I99026394796125974c5f2c3660a88becb92c9df3
Reviewed-on: https://go-review.googlesource.com/c/go/+/170318
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2019-04-23 17:58:12 +00:00
Keith Randall
fd788a86b6 cmd/compile: always mark atColumn1 results as statements
In 31618, we end up comparing the is-stmt-ness of positions
to repurpose real instructions as inline marks. If the is-stmt-ness
doesn't match, we end up not being able to remove the inline mark.

Always use statement-full positions to do the matching, so we
always find a match if there is one.

Also always use positions that are statements for inline marks.

Fixes #31618

Change-Id: Idaf39bdb32fa45238d5cd52973cadf4504f947d5
Reviewed-on: https://go-review.googlesource.com/c/go/+/173324
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2019-04-23 17:39:11 +00:00
Matthew Dempsky
a152dd0438 cmd/compile: respect -newescape in genwrapper
Noticed while preparing a CL for Go 1.14 to remove esc.go.

Change-Id: Ic12be33f5b16c8424d85f373fa450247be086078
Reviewed-on: https://go-review.googlesource.com/c/go/+/173298
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-04-23 17:33:29 +00:00
Michael Munday
f0fdbb1e8b math: consolidate assembly stub implementations
Where assembly functions are just jumps to the Go implementation
put them into a stubs_<arch>.s file. This reduces the number of
files considerably and makes it easier to see what is really
implemented in assembly.

I've also run the stubs files through asmfmt to format them in
a more consistent way.

Eventually we should replace these 'stub' assembly files with
a pure Go implementation now that we have mid-stack inlining
(see #31362).

Change-Id: If5b2022dcc23e1299f1b7ba79884f1b1263d0f7f
Reviewed-on: https://go-review.googlesource.com/c/go/+/173398
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-04-23 14:50:16 +00:00
Benny Siegert
3d63166232 A: Add Maya Rashish (individual CLA)
Change-Id: I1380229c250a6100dc7e0bcf59be8df425a3efac
Reviewed-on: https://go-review.googlesource.com/c/go/+/173399
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-04-23 14:40:30 +00:00
Benny Siegert
d0fadb93c2 doc: update wording in contribution guide
The top right menu in Gerrit is now a gear icon, and the link
has a slightly different title.

Change-Id: I3f5d194f31ad09a99416a45db392aa4b5c7d98ff
Reviewed-on: https://go-review.googlesource.com/c/go/+/173400
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-04-23 14:39:25 +00:00
Nikhil Benesch
213d1cf3ca cmd/go: include AR env var in gccgo build IDs
The gccgo toolchain uses the archiver specified by the AR environment
variable, or `ar` by default. Teach the build ID to take the value of
this environment variable into account, since different archivers can
produce different results.

Fix #30046.

Change-Id: Ia6821258d54eecedb9026afc38a515cd564c45cb
Reviewed-on: https://go-review.googlesource.com/c/go/+/160897
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2019-04-23 14:38:17 +00:00
Russ Cox
d92bc7a55a encoding/json: document HTML escaping in Compact
Make explicit that Compact does HTML escaping.

Fixes #30357.

Change-Id: I4648f8f3e907d659db977d07253f716df6e07d7b
Reviewed-on: https://go-review.googlesource.com/c/go/+/173417
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-04-23 14:22:20 +00:00
Russ Cox
b51c157025 cmd/go: move runtime/debug.modinfo to runtime.modinfo
It is easier to ensure that the symbol is always present
if we move it to package runtime. Avoids init-time work.
Also moves it next to buildVersion, the other similar symbol.

Setting up for "go version <binary>".

For #31624.

Change-Id: I943724469ce6992153e701257eb6f12da88c8e4e
Reviewed-on: https://go-review.googlesource.com/c/go/+/173341
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-04-23 14:21:30 +00:00
Shubham Sharma
fac3b5d05e net: add IsNotFound field to DNSError
This adds the ability to determine if a lookup error was
due to a non-existent hostname. Previously users needed
to do string matching on the DNSError.Err value.

Fixes #28635

Change-Id: If4bd3ad32cbc2db5614f2c6b72e0a9161d813efa
Reviewed-on: https://go-review.googlesource.com/c/go/+/168597
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-04-23 14:11:33 +00:00
Daniel Martí
7e08c7f43d encoding/json: index names for the struct decoder
In the common case, structs have a handful of fields and most inputs
match struct field names exactly.

The previous code would do a linear search over the fields, stopping at
the first exact match, and otherwise using the first case insensitive
match.

This is unfortunate, because it means that for the common case, we'd do
a linear search with bytes.Equal. Even for structs with only two or
three fields, that is pretty wasteful.

Worse even, up until the exact match was found via the linear search,
all previous fields would run their equalFold functions, which aren't
cheap even in the simple case.

Instead, cache a map along with the field list that indexes the fields
by their name. This way, a case sensitive field search doesn't involve a
linear search, nor does it involve any equalFold func calls.

This patch should also slightly speed up cases where there's a case
insensitive match but not a case sensitive one, as then we'd avoid
calling bytes.Equal on all the fields. Though that's not a common case,
and there are no benchmarks for it.

name           old time/op    new time/op    delta
CodeDecoder-8    11.0ms ± 0%    10.6ms ± 1%  -4.42%  (p=0.000 n=9+10)

name           old speed      new speed      delta
CodeDecoder-8   176MB/s ± 0%   184MB/s ± 1%  +4.62%  (p=0.000 n=9+10)

name           old alloc/op   new alloc/op   delta
CodeDecoder-8    2.28MB ± 0%    2.28MB ± 0%    ~     (p=0.725 n=10+10)

name           old allocs/op  new allocs/op  delta
CodeDecoder-8     76.9k ± 0%     76.9k ± 0%    ~     (all equal)

Updates #28923.

Change-Id: I9929c1f06c76505e5b96914199315dbdaae5dc76
Reviewed-on: https://go-review.googlesource.com/c/go/+/172918
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-04-23 05:54:51 +00:00
Josh Bleecher Snyder
980a57a84b cmd/compile: clean up string/bytes/runes conversion code
Combine the OBYTES2STR and ORUNES2STR cases, as they are identical.

Clean up the construction, commenting, and spacing of the other cases,
and make them all match.

Passes toolstash-check.

Change-Id: I1be8a528927caeb15e49cb12ca0f11c0827dadd9
Reviewed-on: https://go-review.googlesource.com/c/go/+/173322
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-23 02:14:40 +00:00
Russ Cox
f0e9754696 cmd/go: add env -w and env -u to set and unset default env vars
Setting environment variables for go command configuration
is too difficult and system-specific. This CL adds go env -w,
to change the default settings more easily, in a portable way.
It also adds go env -u, to unset those changes.

See https://golang.org/design/30411-env for details.

Fixes #30411.

Change-Id: I36e83f55b666459f8f7f482432a4a6ee015da71d
Reviewed-on: https://go-review.googlesource.com/c/go/+/171137
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
2019-04-23 00:58:08 +00:00
Matthew Dempsky
e40dffe55a cmd/compile: refactor visitBottomUp to use inspectList
Passes toolstash-check.

Change-Id: I02efba7bab3ea49d87c8472bbb99116565bf8423
Reviewed-on: https://go-review.googlesource.com/c/go/+/173321
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-04-22 23:03:04 +00:00
Matthew Dempsky
ef2806e4ab cmd/compile: change visitBottomUp from post-order traversal to pre-order
No meaningful change, but allows the followup CL to pass
toolstash-check.

Change-Id: I1d852c97838be3f84cf795bc9daec9b15c705956
Reviewed-on: https://go-review.googlesource.com/c/go/+/173320
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-22 23:02:46 +00:00
Benoit Sigoure
415da714fa net/http: document that Basic Auth may require URL encoding
Explicitly warn callers that no URL encoding is performed and
that they might need to do it.

Fixes #31577

Change-Id: I52dc3fd2798ba8c3652d4a967b1c5c48eb69f43b
Reviewed-on: https://go-review.googlesource.com/c/go/+/173319
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-04-22 22:54:41 +00:00
Tyler Bui-Palsulich
1f0c102a57 cmd/go: expand cannot determine module path error
See suggestion 2 of #31543 by thepudds.

We may want to expand 'go help mod init' in the future to document what
the module path should look like.

Change-Id: Ia559fa96fda871e011d53f42a803175abc512202
Reviewed-on: https://go-review.googlesource.com/c/go/+/173318
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
2019-04-22 21:39:57 +00:00
Shawn Elliott
e6ae4e86ad cmd/go/internal/generate: stop premature variable substitution in commands
go:generate commands passed no arguments are currently subject
to premature variable substitution due to mistakenly assuming append
guarantees a copy.  The change fixes this by forcing a slice copy at
each invocation of a command.

The previous code assumed that append would always generate a
copy of its inputs. However, append wouldn't create a copy if there was
no need to increase capacity and it would just return the original
input slice. This resulted in premature variable substitutions in
the "master word list" of generate commands, thus yielding incorrect
results across multiple invocations of the same command when the
body contained substitutions e.g. environment variables, moreover
these can change during the lifetime of go:generate processing a
file.

Note that this behavior would not manifest itself if any arguments were
passed to the command, because append would make a copy of the slice
as it needed to increase its capacity.   The "hacky" work-around was to
always pass at least one argument to any command, even if the
command ignores it.  e.g.,
       //go:generate MyNoArgsCmd ' '

This CL fixes that issue and removes the need for the hack mentioned
above.

Fixes #31608

Change-Id: I782ac2234bd7035a37f61c101ee4aee38ed8d29f
GitHub-Last-Rev: 796d343019
GitHub-Pull-Request: golang/go#31527
Reviewed-on: https://go-review.googlesource.com/c/go/+/172580
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
2019-04-22 18:34:50 +00:00
Keith Randall
43001a0dc9 cmd/compile: use correct package name for stack object symbol
Stack object generation code was always using the local package name
for its symbol. Normally that doesn't matter, as we usually only
compile functions in the local package. But for wrappers, the compiler
generates functions which live in other packages. When there are two
other packages with identical functions to wrap, the same name appears
twice, and the compiler goes boom.

Fixes #31252

Change-Id: I7026eebabe562cb159b8b6046cf656afd336ba25
Reviewed-on: https://go-review.googlesource.com/c/go/+/171464
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2019-04-22 17:40:48 +00:00
Maya Rashish
d1f43ccef7 runtime: use named macros on NetBSD
It will use the full names that appear in netbsd's /usr/include/sys/syscall.h names.
This adds some compat-goo (sys_sigprocmask->SYS_sigprocmask14), which might not be pretty, but the information about whether the compat version is used is probably important, as Go will keep using interfaces even after they are considered compatibility, which has caused problems in the past.
also, the same names appear in ktrace (with the numbers).

Change-Id: Idc1bb254ee33757a39ba224d91e8fbb0331e2149
GitHub-Last-Rev: b915e8f8a3
GitHub-Pull-Request: golang/go#31594
Reviewed-on: https://go-review.googlesource.com/c/go/+/173158
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-22 17:19:23 +00:00
Austin Clements
744fcfec4e runtime: improve mstart comments
Some of the comments were unclear or outdated.

Change-Id: I02e01bf60def0074c1fa760e94aa992e9e4969b9
Reviewed-on: https://go-review.googlesource.com/c/go/+/172987
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
2019-04-22 16:01:16 +00:00
Daniel Martí
fe1afe8d4c encoding/json: avoid work when unquoting strings
We can work out how many bytes can be unquoted trivially in
rescanLiteral, which already iterates over a string's bytes.

Removing the extra loop in unquoteBytes simplifies the function and
speeds it up, especially when decoding simple strings, which are common.

While at it, we can remove unnecessary checks like len(s)<2 and
s[0]=='"'. Add a comment explaining why.

name           old time/op    new time/op    delta
CodeDecoder-8    11.2ms ± 0%    11.1ms ± 1%  -1.63%  (p=0.000 n=9+10)

name           old speed      new speed      delta
CodeDecoder-8   173MB/s ± 0%   175MB/s ± 1%  +1.66%  (p=0.000 n=9+10)

Updates #28923.

Change-Id: I2436a3a7f8148a2f7a6a4cdbd7dec6b32ef5e20c
Reviewed-on: https://go-review.googlesource.com/c/go/+/151157
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-04-22 15:07:38 +00:00
erifan01
d17d41e58d math/big: optimize mulAddVWW on arm64 for better performance
Unroll the cycle 4 times to reduce load overhead.

Benchmarks:
name                old time/op    new time/op    delta
MulAddVWW/1-8         15.9ns ± 0%    11.9ns ± 0%  -24.92%  (p=0.000 n=8+8)
MulAddVWW/2-8         16.1ns ± 0%    13.9ns ± 1%  -13.82%  (p=0.000 n=8+8)
MulAddVWW/3-8         18.9ns ± 0%    17.3ns ± 0%   -8.47%  (p=0.000 n=8+8)
MulAddVWW/4-8         21.7ns ± 0%    19.5ns ± 0%  -10.14%  (p=0.000 n=8+8)
MulAddVWW/5-8         25.1ns ± 0%    22.5ns ± 0%  -10.27%  (p=0.000 n=8+8)
MulAddVWW/10-8        41.6ns ± 0%    40.0ns ± 0%   -3.79%  (p=0.000 n=8+8)
MulAddVWW/100-8        368ns ± 0%     363ns ± 0%   -1.36%  (p=0.000 n=8+8)
MulAddVWW/1000-8      3.52µs ± 0%    3.52µs ± 0%   -0.14%  (p=0.000 n=8+8)
MulAddVWW/10000-8     35.1µs ± 0%    35.1µs ± 0%   -0.01%  (p=0.000 n=7+6)
MulAddVWW/100000-8     351µs ± 0%     351µs ± 0%   +0.15%  (p=0.038 n=8+8)

Change-Id: I052a4db286ac6e4f3293289c7e9a82027da0405e
Reviewed-on: https://go-review.googlesource.com/c/go/+/155780
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-04-22 14:45:16 +00:00
erifan01
f8f265b9cf cmd/compile: intrinsify math/bits.Sub64 for arm64
This CL instrinsifies Sub64 with arm64 instruction sequence NEGS, SBCS,
NGC and NEG, and optimzes the case of borrowing chains.

Benchmarks:
name              old time/op       new time/op       delta
Sub-64            2.500000ns +- 0%  2.048000ns +- 1%  -18.08%  (p=0.000 n=10+10)
Sub32-64          2.500000ns +- 0%  2.500000ns +- 0%     ~     (all equal)
Sub64-64          2.500000ns +- 0%  2.080000ns +- 0%  -16.80%  (p=0.000 n=10+7)
Sub64multiple-64  7.090000ns +- 0%  2.090000ns +- 0%  -70.52%  (p=0.000 n=10+10)

Change-Id: I3d2664e009a9635e13b55d2c4567c7b34c2c0655
Reviewed-on: https://go-review.googlesource.com/c/go/+/159018
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-22 14:40:20 +00:00
Austin Clements
db42bb3b70 runtime: error formatting fix
g.m is an muintptr, but we want to print it in hex like a pointer.

Change-Id: Ifc48ed77fb2e93cff7a49d98adc7b9679d26c3b1
Reviewed-on: https://go-review.googlesource.com/c/go/+/172988
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-04-22 14:08:47 +00:00
Josh Bleecher Snyder
68d4b1265e cmd/compile: reduce bits.Div64(0, lo, y) to 64 bit division
With this change, these two functions generate identical code:

func f(x uint64) (uint64, uint64) {
	return bits.Div64(0, x, 5)
}

func g(x uint64) (uint64, uint64) {
	return x / 5, x % 5
}

Updates #31582

Change-Id: Ia96c2e67f8af5dd985823afee5f155608c04a4b6
Reviewed-on: https://go-review.googlesource.com/c/go/+/173197
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-20 19:34:03 +00:00
Maya Rashish
d23cba683e all: add start of netbsd/arm64 support
This works well enough to run some code natively on arm64, but not well enough for more complicated code. I've been suggested to start a pull request anyway.

Updates #30824

Change-Id: Ib4f63e0e8a9edfc862cf65b5f1b0fbf9a8a1628e
GitHub-Last-Rev: b01b105e04
GitHub-Pull-Request: golang/go#29398
Reviewed-on: https://go-review.googlesource.com/c/go/+/155739
Run-TryBot: Benny Siegert <bsiegert@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>
2019-04-20 15:02:01 +00:00
Maya Rashish
78f0de10ec runtime: move linux specific code into linux specific files
Allows us to stop whitelisting this error on many OS/arch combinations

XXX I'm not sure I am running vet correctly, and testing all platforms right.

Change-Id: I29f548bd5f4a63bd13c4d0667d4209c75c886fd9
GitHub-Last-Rev: 52f6ff4a6b
GitHub-Pull-Request: golang/go#31583
Reviewed-on: https://go-review.googlesource.com/c/go/+/173157
Run-TryBot: Benny Siegert <bsiegert@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>
2019-04-20 14:20:24 +00:00
Bryan C. Mills
a1c481d851 cmd/go: only add a 'go' directive on 'go mod tidy' or when a conversion occurs
If the go.mod file exists and is empty, we initialize it from any of
various formats supported by legacy dependency-management tools.

We also initialize the 'go' directive at that point: we know that the
go.mod file is incomplete, because it does not reflect the information
in the legacy configuration file, and since we know that the go.mod
file is incomplete, we should complete it with as much information as
we have — including the version of the language currently in use.

However, if there is no legacy configuration file present, then we
cannot infer that the go.mod file is incomplete: it may correctly
specify a module without external dependencies. In that case, we
should not initialize the 'go' directive either: the user will not be
expecting unnecessary edits to the go.mod file, and we generally do
not make unnecessary-but-helpful edits unless 'go mod tidy' is invoked
explicitly.

Fixes #30790
Fixes #31100

Change-Id: I05a7872bce54a917c10d910cd9a616cab52e2730
Reviewed-on: https://go-review.googlesource.com/c/go/+/169877
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-04-19 21:16:38 +00:00
Matthew Dempsky
9f9e17a82f cmd/compile: fix ICE from go/defer call to variadic function
The special case logic for go/defer arguments in Escape.call was
scattered around a bit and was somewhat inconsistently handled across
different types of function calls and parameters. This CL pulls the
logic out into a separate callStmt method that's used uniformly for
all kinds of function calls and arguments.

Fixes #31573.

Change-Id: Icdcdf611754dc3fcf1af7cb52879fb4b73a7a31f
Reviewed-on: https://go-review.googlesource.com/c/go/+/173019
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-04-19 20:45:14 +00:00
David Chase
376ce8c880 cmd/compile: shortcut intrinsic inlining AFTER getcallerXX check
A check in inl.go to prevent inlining of functions calling
either getcallerpc or getcallersp does not work when these
functions are intrinsics. Swap checks to fix.

Includes test.

No bug, this was discovered in the course of a ridiculous
experiment with inlining.

Change-Id: Ie1392523bb89882d586678f2674e1a4eadc5e431
Reviewed-on: https://go-review.googlesource.com/c/go/+/172217
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-04-19 20:18:29 +00:00
Than McIntosh
dc193dee15 go/internal/gccgoimporter: improve alias handling for anonymous fields
The code in the parser that deals with anonymous structure fields
records the fact that a field is anonymous, then tries to install a proxy
name for the field based on the name of the type used to declare
the field. If that type was an alias, the current recipe for determining
the proxy name was not working properly; enhance the code to recover
and report the alias name used.

Fixes #31540.

Change-Id: I9b7369ed558a288b56d85170c6f1144daf5228eb
Reviewed-on: https://go-review.googlesource.com/c/go/+/172603
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-04-19 19:47:53 +00:00
Than McIntosh
4590abe072 cmd/link: adjust whitelist for -strictdups checking for plan9
Add a couple of additional entries to the white list used to screen
out errors for builtin functions; these correspond to cases
that appear to come up only on the plan9 builder.

Updates #31503.

Change-Id: I48ab942ab2894240efe651ec7b7eace7aa5cb45e
Reviewed-on: https://go-review.googlesource.com/c/go/+/172986
Reviewed-by: David du Colombier <0intro@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-19 19:47:04 +00:00
Yuval Pavel Zholkover
059f2d4a46 os: disable the use of netpoll on directories as well on *BSDs
Follow up CL 156379.

Updates #19093

Change-Id: I5ea3177fc5911d3af71cbb32584249e419e9d4a3
Reviewed-on: https://go-review.googlesource.com/c/go/+/172937
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-04-19 19:24:47 +00:00
Bryan C. Mills
14b5b4a2a1 cmd/go/internal/modload: fix boundary conditions in matchPackages
This makes the boundary logic of matchPackages consistent with
modload.dirInModule.

Previously, matchPackages always stopped at go.mod file, even within
the vendor tree. However, we do not guarantee that the vendor tree is
free of such files in general.

matchPackages also issued needless stat operations for modules in the
module cach, which we already know to be free of nested modules. On
systems with slow filesystems (such as macOS), those extra calls could
potentially slow package matching considerably.

Change-Id: I71979ab752e1d3971b370b37085d30502690413b
Reviewed-on: https://go-review.googlesource.com/c/go/+/172985
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
2019-04-19 18:37:41 +00:00
Cherry Zhang
dbe32284ff cmd/link: mmap object data
This resurrects CL 121198, except that this time we map read-only.

In case that we need to apply relocations to the symbol's
content that is backed by read-only memory, we do our own copy-
on-write. This can happen if we failed to mmap the output file,
or we build for Wasm.

Memory profile for building k8s.io/kubernetes/cmd/kube-apiserver
on Linux/AMD64:

Old (before this sequence of CLs):
inuse_space 1598.75MB total
669.87MB 41.90% 41.90%   669.87MB 41.90%  cmd/link/internal/objfile.(*objReader).readSlices

New:
inuse_space 1280.45MB total
441.18MB 34.46% 34.46%   441.18MB 34.46%  cmd/link/internal/objfile.(*objReader).readSlices

Change-Id: I6b4d29d6eee9828089ea3120eb38c212db21330b
Reviewed-on: https://go-review.googlesource.com/c/go/+/170741
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-19 18:25:56 +00:00
Cherry Zhang
f957a7e357 cmd/link: apply relocations later
Move the phase of applying relocations later, after the sections
and segments are written to the mmap'd output region. Then apply
relocations directly in the output region, instead of the input.
So the input slices we read in don't need to be modified.

This is in preparation for mmap'ing input files read-only.

Change-Id: If9c80657b4469da36aec5a9ab6acf664f5af8fa0
Reviewed-on: https://go-review.googlesource.com/c/go/+/170739
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-04-19 18:25:33 +00:00
Cherry Zhang
248444d5eb cmd/link: apply DWARF relocations while doing compression
We are preparing for applying relocations to the output buffer.
However, for DWARF compression, relocations need to be applied
before compression, but we don't have an output buffer at that
time. We also cannot delay DWARF compression to when we mmap the
output file, because we need the size of the DWARF sections to
compute the file size.

Instead of applying all the relocations together, we apply
relocations in DWARF sections one symbol at a time, right before
it is writing out for compression. As the symbol content may be
in read-only memory (in the future), we use a temporary buffer
for applying the relocations, and immediately write it out.

If compression is not used, relocations are still applied all
together.

This is in preparation for mmap'ing input files read-only.

Change-Id: Iae6d2dd71313897d5054bcc458d3bb78075b30c3
Reviewed-on: https://go-review.googlesource.com/c/go/+/171397
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-04-19 18:25:20 +00:00
Cherry Zhang
15a31bd9c8 cmd/link: apply R_DWARFFILEREF later
Apply R_DWARFFILEREF relocations later, along with other
relocations, so that we don't modify symbols' contents before
they are written to the output buffer.

This is in preparation for mmap'ing input files read-only.

Change-Id: I8e9ffb2f05acf8f198589b8770f277beb3847541
Reviewed-on: https://go-review.googlesource.com/c/go/+/170740
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-04-19 18:25:09 +00:00
Cherry Zhang
b2f94d3e88 cmd/link: mmap output file
Use mmap for writing most of the output file content,
specifically, the sections and segments. After layout, we
already know the sizes and file offsets for the sections and
segments. So we can just write the bytes by copying to a mmap'd
backing store.

The writing of the output file is split into two parts. The first
part writes the sections and segments to the mmap'd region. The
second part writes some extra content, for which we don't know
the size, so we use direct file IO.

This is in preparation for mmap'ing input files read-only.

Change-Id: I9f3b4616a9f96bfd5c940d74c50aacd6d330f7d2
Reviewed-on: https://go-review.googlesource.com/c/go/+/170738
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-04-19 18:24:44 +00:00
Bryan C. Mills
47150aafbf cmd/go/internal/modfetch: comment on known bug in isVendoredPackage
Fixes #31562

Change-Id: Ida30dd8071eccb6b490ab89a1de087038fe26796
Reviewed-on: https://go-review.googlesource.com/c/go/+/172977
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
2019-04-19 18:08:17 +00:00
Brad Fitzpatrick
64e29f94e2 internal/goversion: add new package, move Go 1.x constant there out of go/build
Found by Josh, who says in the bug that it shrinks cmd/compile by 1.6 MB (6.5%).

Fixes #31563

Change-Id: I35127af539630e628a0a4f2273af519093536c38
Reviewed-on: https://go-review.googlesource.com/c/go/+/172997
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2019-04-19 18:04:35 +00:00
Cherry Zhang
97252f620f runtime: suppress thread event prints in gdb test
Pass "set print thread-events off" to gdb to suppress thread
event prints, like "[New Thread 0xe7b83b40 (LWP 18609)]". We
don't check them, and the extra output may confuse our other
checks, in particular, checkCleanBacktrace.

Hopefully fixes #31569.

Change-Id: I6549e1280da7afa1d2e38da2b2fa7cc18c2f0373
Reviewed-on: https://go-review.googlesource.com/c/go/+/172980
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-19 17:12:13 +00:00
Ian Lance Taylor
4a11914130 bootstrap.bash: make source writable before cleaning
Otherwise the "git clean" command fails with errors like
    rm: cannot remove '/home/iant/go-linux-ppc64-bootstrap/pkg/mod/golang.org/x/text@v0.0.0-20170915032832-14c0d48ead0c/encoding/simplifiedchinese/all.go': Permission denied

Change-Id: Iecfb1fed6d59819d7fdceb9e391a2b3f81ea620c
Reviewed-on: https://go-review.googlesource.com/c/go/+/172998
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-19 17:04:30 +00:00
Ian Lance Taylor
4c236b9b09 cmd/link: require cgo support for TestSectionsWithSameName
The test doesn't really require cgo, but it does require that we know
the right flags to use to run the C compiler, and that is not
necessarily correct if we don't support cgo.

Fixes #31565

Change-Id: I04dc8db26697caa470e91ad712376aa621cf765d
Reviewed-on: https://go-review.googlesource.com/c/go/+/172981
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-19 17:03:55 +00:00
Kai Dong
5ccaf2c6ad sync: update comment
Comment update.

Change-Id: If0d054216f9953f42df04647b85c38008b85b026
GitHub-Last-Rev: 133b4670be
GitHub-Pull-Request: golang/go#31539
Reviewed-on: https://go-review.googlesource.com/c/go/+/172700
Reviewed-by: Austin Clements <austin@google.com>
2019-04-19 16:15:36 +00:00
Josh Bleecher Snyder
4aeac68c92 runtime, cmd/compile: re-order PCDATA and FUNCDATA indices
The pclntab encoding supports writing only some PCDATA and FUNCDATA values.
However, the encoding is dense: The max index in use determines the space used.
We should thus choose a numbering in which frequently used indices are smaller.

This change re-orders the PCDATA and FUNCDATA indices using that principle,
using a quick and dirty instrumentation to measure index frequency.

It shrinks binaries by about 0.5%.

Updates #6853

file      before    after     Δ       %       
go        14745044  14671316  -73728  -0.500% 
addr2line 4305128   4280552   -24576  -0.571% 
api       6095800   6058936   -36864  -0.605% 
asm       4930928   4906352   -24576  -0.498% 
buildid   2881520   2861040   -20480  -0.711% 
cgo       4896584   4867912   -28672  -0.586% 
compile   25868408  25770104  -98304  -0.380% 
cover     5319656   5286888   -32768  -0.616% 
dist      3654528   3634048   -20480  -0.560% 
doc       4719672   4691000   -28672  -0.607% 
fix       3418312   3393736   -24576  -0.719% 
link      6137952   6109280   -28672  -0.467% 
nm        4250536   4225960   -24576  -0.578% 
objdump   4665192   4636520   -28672  -0.615% 
pack      2297488   2285200   -12288  -0.535% 
pprof     14735332  14657508  -77824  -0.528% 
test2json 2834952   2818568   -16384  -0.578% 
trace     11679964  11618524  -61440  -0.526% 
vet       8452696   8403544   -49152  -0.581% 

Change-Id: I30665dce57ec7a52e7d3c6718560b3aa5b83dd0b
Reviewed-on: https://go-review.googlesource.com/c/go/+/171760
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-04-19 15:40:42 +00:00
Josh Bleecher Snyder
c1544ff906 cmd/compile: move phi tighten after critical
The phi tighten pass moves rematerializable phi args
to the immediate predecessor of the phis.
This reduces value lifetimes for regalloc.

However, the critical edge removal pass can introduce
new blocks, which can change what a block's
immediate precedessor is. This can result in tightened
phi args being spilled unnecessarily.

This change moves the phi tighten pass after the
critical edge pass, when the block structure is stable.

This improves the code generated for

func f(s string) bool { return s == "abcde" }

Before this change:

"".f STEXT nosplit size=44 args=0x18 locals=0x0
	0x0000 00000 (x.go:3)	MOVQ	"".s+16(SP), AX
	0x0005 00005 (x.go:3)	CMPQ	AX, $5
	0x0009 00009 (x.go:3)	JNE	40
	0x000b 00011 (x.go:3)	MOVQ	"".s+8(SP), AX
	0x0010 00016 (x.go:3)	CMPL	(AX), $1684234849
	0x0016 00022 (x.go:3)	JNE	36
	0x0018 00024 (x.go:3)	CMPB	4(AX), $101
	0x001c 00028 (x.go:3)	SETEQ	AL
	0x001f 00031 (x.go:3)	MOVB	AL, "".~r1+24(SP)
	0x0023 00035 (x.go:3)	RET
	0x0024 00036 (x.go:3)	XORL	AX, AX
	0x0026 00038 (x.go:3)	JMP	31
	0x0028 00040 (x.go:3)	XORL	AX, AX
	0x002a 00042 (x.go:3)	JMP	31

Observe the duplicated blocks at the end.
After this change:

"".f STEXT nosplit size=40 args=0x18 locals=0x0
	0x0000 00000 (x.go:3)	MOVQ	"".s+16(SP), AX
	0x0005 00005 (x.go:3)	CMPQ	AX, $5
	0x0009 00009 (x.go:3)	JNE	36
	0x000b 00011 (x.go:3)	MOVQ	"".s+8(SP), AX
	0x0010 00016 (x.go:3)	CMPL	(AX), $1684234849
	0x0016 00022 (x.go:3)	JNE	36
	0x0018 00024 (x.go:3)	CMPB	4(AX), $101
	0x001c 00028 (x.go:3)	SETEQ	AL
	0x001f 00031 (x.go:3)	MOVB	AL, "".~r1+24(SP)
	0x0023 00035 (x.go:3)	RET
	0x0024 00036 (x.go:3)	XORL	AX, AX
	0x0026 00038 (x.go:3)	JMP	31

Change-Id: I12c81aa53b89456cb5809aa5396378245f3beda9
Reviewed-on: https://go-review.googlesource.com/c/go/+/172597
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-04-19 15:39:53 +00:00
Bryan C. Mills
d68ac59113 {,cmd/}vendor: rerun 'go mod vendor' to prune ignored files
Updates #31088

Change-Id: Ia126e4e83ac5cb12c2c4151d5e5c975497598f24
Reviewed-on: https://go-review.googlesource.com/c/go/+/172979
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-04-19 15:36:19 +00:00