Cherry Zhang [Fri, 18 Oct 2019 21:08:35 +0000 (17:08 -0400)]
[dev.link] cmd/link: assign special indices for builtin functions
Compiler-generated function references (e.g. call to
runtime.newobject) appear frequently. We assign special indices
for them, so they don't need to be referenced by name.
Cherry Zhang [Fri, 18 Oct 2019 16:11:56 +0000 (12:11 -0400)]
[dev.link] cmd/link: use string map for name lookup
As we no longer include static symbols into the name lookup table,
it is basically just two maps, one for ABI0, one for ABIInternal.
Just use two maps instead. It may be slightly faster to use
string-keyed maps than struct-keyed maps (still need performance
data to confirm).
For now, allow external symbols being referenced by name, as
external objects don't use index.
Change-Id: I60cedaa7346fce7535970780bc67f93c82160646
Reviewed-on: https://go-review.googlesource.com/c/go/+/201999
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Jeremy Faller <jeremy@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>
Cherry Zhang [Fri, 18 Oct 2019 15:19:32 +0000 (11:19 -0400)]
[dev.link] cmd/link: do not put static symbols into name lookup table
Since the previous CL, we will not reference static symbols by
name. Therefore no need to put them into the name lookup table.
On Linux/ARM, in runtime/internal/atomic/sys_linux_arm.s, the
kernelcas function has a definition and a reference written in
two different forms, one with package prefix, one without. This
way, the assembler cannot know they are the same symbol, only the
linker knows. This is quite unusual, unify the names to so the
assembler can resolve it to index.
Cherry Zhang [Fri, 18 Oct 2019 14:30:04 +0000 (10:30 -0400)]
[dev.link] cmd/internal/obj: use index for static symbols
In assembly we always reference symbols by name. But for static
symbols, as they are reachable only within the current file, we
can assign them local indices and use the indices to reference
them. The index is only meaningful locally, and it is fine.
Cherry Zhang [Thu, 17 Oct 2019 01:42:18 +0000 (21:42 -0400)]
[dev.link] cmd: reference symbols by name when linking against Go shared library
When building a program that links against Go shared libraries,
it needs to reference symbols defined in the shared library. At
compile time, we don't know where the shared library boundary is.
If we reference a symbol in package p by index, and package p is
actually part of a shared library, we cannot resolve the index at
link time, as the linker doesn't see the object file of p.
So when linking against Go shared libraries, always use named
reference for now.
To do this, the compiler needs to know whether we will be linking
against Go shared libraries. The -dynlink flag kind of indicates
that (as the document says), but currently it is actually
overloaded: it is also used when building a plugin or a shared
library, which is self-contained (if -linkshared is not otherwise
specified) and could use index for symbol reference. So we
introduce another compiler flag, -linkshared, specifically for
linking against Go shared libraries. The go command will pass
this flag if its -linkshared flag is specified
("go build -linkshared").
There may be better way to handle this. For example, we can
put the symbol indices in a special section in the shared library
that the linker can read. Or we can generate some per-package
description file to include the indices. (Currently we generate
a .shlibname file for each package that is included in a shared
library, which contains the path of the library. We could
consider extending this.) That said, this CL is a stop-gap
solution. And it is no worse than the old object files.
If we were to redesign the build system so that the shared
library boundary is known at compile time, we could use indices
for symbol references that do not cross shared library boundary,
as well as doing other things better.
Cherry Zhang [Thu, 17 Oct 2019 22:42:38 +0000 (18:42 -0400)]
[dev.link] cmd/link: allow either of duplicated symbols being dupok
If two symbols have the same name, the old code allows either one
being dupok (preferably both, but either is ok). Currently, the
new code only works when the new symbol being dupok (or both).
Allow only old symbol being dupok as well.
One example for this is the tls_g variable on ARM64 and PPC64
when the race detector is enabled.
cmd/internal/obj/arm64: add support of NOOP instruction
This patch uses symbol NOOP to support arm64 instruction NOP. In
arm64, NOP stands for that No Operation does nothing, other than
advance the value of the program counter by 4. This instruction
can be used for instruction alignment purposes. This patch uses
NOOP to support arm64 instruction NOP, because we have a generic
"NOP" instruction, which is a zero-width pseudo-instruction.
In arm64, instruction NOP is an alias of HINT #0. This patch adds
test cases for instruction HINT #0.
Alberto Donizetti [Sat, 28 Sep 2019 17:02:15 +0000 (19:02 +0200)]
math/bits: add Rem, Rem32, Rem64
The Div functions in math/bits (Div, Div32, and Div64) compute both
quotients and remainders, but they panic if the quotients do not not
fit a 32/64 uint.
Since, on the other hand, the remainder will always fit the size of
the divisor, it is useful to have Div variants that only compute the
remainder, and don't panic on a quotient overflow.
This change adds to the math/bits package three new functions:
Rem(hi, lo, y uint) uint
Rem32(hi, lo, y uint32) uint32
Rem64(hi, lo, y uint64) uint64
which can be used to compute (hi,lo)%y even when the quotient
overflows the uint size.
Fixes #28970
Change-Id: I119948429f737670c5e5ceb8756121e6a738dbdc
Reviewed-on: https://go-review.googlesource.com/c/go/+/197838
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
Robert Griesemer [Thu, 17 Oct 2019 23:28:38 +0000 (16:28 -0700)]
go/types: don't update the underlying type of an imported type
Updating the underlying type of an imported type (even though
is was set to the same type again) leads to a race condition
if the imported package is imported by separate, concurrently
type-checked packages.
Matthew Dempsky [Thu, 17 Oct 2019 20:16:15 +0000 (13:16 -0700)]
cmd/compile: fix -d=checkptr for named unsafe.Pointer types
We need to explicitly convert pointers to unsafe.Pointer before
passing to the runtime checkptr instrumentation in case the user
declared their own type with underlying type unsafe.Pointer.
Updates #22218.
Fixes #34966.
Change-Id: I3baa2809d77f8257167cd78f57156f819130baa8
Reviewed-on: https://go-review.googlesource.com/c/go/+/201782
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
Cherry Zhang [Thu, 17 Oct 2019 05:17:42 +0000 (01:17 -0400)]
[dev.link] cmd/link: restore export data hash
With the previous CL, the export data will not change whether it
is compiled with -dynlink flag or not. Restore the export data
hash, and reenable plugin version check.
TODO: it may be still better to just generate a fingerprint for
each package at compile time.
Cherry Zhang [Thu, 17 Oct 2019 05:11:23 +0000 (01:11 -0400)]
[dev.link] cmd/compile: pass index through when re-exporting
When we re-export an imported symbol that has an index, we should
pass the index through. Currently, if the symbol is not
referenced in the generated machine code, it does not get
assigned a package index, and the exporter will not export its
symbol index. Let the exporter handle this case -- if the symbol
has a symbol index but not a package index, still export its
symbol index. This is safe as referenced-by-name symbols always
have their package indices set to a special value.
This should reduce the number of referenced-by-name symbols, and
also make the export data more stable, less dependent on codegen
details.
Matthew Dempsky [Thu, 17 Oct 2019 19:31:07 +0000 (12:31 -0700)]
cmd/compile: escape unsafe.Pointer conversions when -d=checkptr
This CL tweaks escape analysis to treat unsafe.Pointer(ptr) as an
escaping operation when -d=checkptr is enabled. This allows better
detection of unsafe pointer arithmetic and conversions, because the
runtime checkptr instrumentation can currently only detect object
boundaries for heap objects, not stack objects.
Updates #22218.
Fixes #34959.
Change-Id: I856812cc23582fe4d0d401592583323e95919f28
Reviewed-on: https://go-review.googlesource.com/c/go/+/201781
Run-TryBot: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Than McIntosh [Wed, 16 Oct 2019 20:21:42 +0000 (16:21 -0400)]
[dev.link] cmd/link: new loader method for reading relocations in batch
Add a new loader.Relocs method that reads all of the relocations for a
symbol into a slice. Handy in cases where the client knows in advance
that it wants to visit all the relocations on a symbol (as opposed to
just one or two).
Change-Id: I1a420513e160c8bb4b90c9824ae8d5b5de060c15
Reviewed-on: https://go-review.googlesource.com/c/go/+/201721
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Jeremy Faller <jeremy@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
Keith Randall [Thu, 17 Oct 2019 19:31:53 +0000 (12:31 -0700)]
regexp: skip long-running benchmarks if -short is specified
This CL helps race.bash finish in a reasonable amount of
time. Otherwise the Match/Hard1/32M benchmark takes over 1200 seconds
to finish on arm64, triggering a timeout. With this change the regexp
benchmarks as a whole take only about a minute.
Bryan C. Mills [Thu, 17 Oct 2019 13:57:42 +0000 (09:57 -0400)]
os/exec: re-enable TestExtraFiles checks skipped on various OSes
The issues associated with these skipped checks are closed.
If they are working around unfixed bugs, the issues should remain open.
If they are working around unfixable properties of the system, the skips
should refer to those properties rather than closed issues.
Than McIntosh [Wed, 16 Oct 2019 14:39:58 +0000 (10:39 -0400)]
[dev.link] cmd/link: remove unused slow paths from BytesAt/StringAt
This change removes the NewReader function (no longer used by objdump)
and prunes away the now unused code paths from Reader.BytesAt and
Reader.StringAt, which helps with performance. At the moment the
reader operates by always ingesting the entire object file (either via
direct read or by mmap), meaning that there will always be a slice
available for us to index into.
Change-Id: I3af7396effe19e50ed594fe8d82fd2d15465687c
Reviewed-on: https://go-review.googlesource.com/c/go/+/201437
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com> Reviewed-by: Jeremy Faller <jeremy@golang.org>
Than McIntosh [Wed, 16 Oct 2019 13:29:56 +0000 (09:29 -0400)]
[dev.link] cmd/link: record go.itablink symbols during object file read
Change the new loader to keep a note of the set of "go.itablink.*"
symbols (using a small map), and add a method that clients can use to
query whether a given global index corresponds to a "go.itablink.*"
sym. This eliminates one instance of raw symbol name reading/matching
during new deadcode, which should produce a minor speedup.
Than McIntosh [Wed, 16 Oct 2019 13:13:59 +0000 (09:13 -0400)]
[dev.link] cmd: add flag to mark gotype symbols
Add a flag bit to mark symbols in the new object file as containing Go
type information. The use of a flag eliminates the need to do symbol
name matching as part of the new dead code elimination pass, which
should produce a minor speedup.
Change-Id: Iec8700e1139e2c4e310644c0766379865d2d6f82
Reviewed-on: https://go-review.googlesource.com/c/go/+/201399
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Jeremy Faller <jeremy@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
Than McIntosh [Wed, 16 Oct 2019 12:54:58 +0000 (08:54 -0400)]
[dev.link] cmd: convert symbol "shared" flag to object file flag
For the new object file format, don't tag individual symbols with a
"shared" flag, since that characteristic is better off as an attribute
of the containing object file as opposed to the individual symbol. Add
a new flags field in the object file header and put a bit in the flags
if the shared flags is in effect during compilation.
Change-Id: I2cf6d33bf7bf2fd8a7614ae0cd6ef03914777498
Reviewed-on: https://go-review.googlesource.com/c/go/+/201398
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Jeremy Faller <jeremy@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
Matthew Dempsky [Wed, 13 Feb 2019 03:40:42 +0000 (19:40 -0800)]
cmd/compile: add -d=checkptr to validate unsafe.Pointer rules
This CL adds -d=checkptr as a compile-time option for adding
instrumentation to check that Go code is following unsafe.Pointer
safety rules dynamically. In particular, it currently checks two
things:
1. When converting unsafe.Pointer to *T, make sure the resulting
pointer is aligned appropriately for T.
2. When performing pointer arithmetic, if the result points to a Go
heap object, make sure we can find an unsafe.Pointer-typed operand
that pointed into the same object.
These checks are currently disabled for the runtime, and can also be
disabled through a new //go:nocheckptr annotation. The latter is
necessary for functions like strings.noescape, which intentionally
violate safety rules to workaround escape analysis limitations.
Fixes #22218.
Change-Id: If5a51273881d93048f74bcff10a3275c9c91da6a
Reviewed-on: https://go-review.googlesource.com/c/go/+/162237
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
Eugene Kalinin [Fri, 28 Jun 2019 20:59:49 +0000 (23:59 +0300)]
encoding/json: correct caller's name in encoding errors
1. Change mapencode.encode to use fmt.Error rather than MarshalerError.
MarshalerError refer to MarshalJSON, but mapencode.encode does not use that.
2. Add sourceFunc field to MarshalerError to record the name of the function
that creates the error, so that the Error method can report it correctly.
Fixes #29753
Change-Id: I186c2fac8470ae2f9e300501de3730face642230
Reviewed-on: https://go-review.googlesource.com/c/go/+/184119
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Cherry Zhang [Wed, 16 Oct 2019 19:44:04 +0000 (15:44 -0400)]
[dev.link] cmd/link: add basic shared library support in newobj mode
This CL adds basic shared library support in newobj mode. This is
not complete -- there are still tests in misc/cgo/testshared
failing. But at least a simple program works, and some tests
there pass.
Add the mechanism of loading external symbols with contents.
(Before, external symbols are always contentless.) This may
potentially be also used for other host objects.
Michael Munday [Wed, 16 Oct 2019 20:49:09 +0000 (21:49 +0100)]
crypto/ecdsa: remove s390x assembly
This a revert of CL 174437 and follow up fix CL 201317.
The s390x assembly in this package makes use of an instruction
(specifically KDSA) which is not supported by the current build
machine. Remove this assembly for now, we can revisit this
functionality once we have a newer build machine and can ensure
that this assembly is well tested.
Emmanuel T Odeke [Wed, 2 Oct 2019 20:36:27 +0000 (13:36 -0700)]
io/ioutil: support predictable prefix,suffix for TempDir with *
Allow TempDir to create directories with predictable
prefixes and suffixes, separated by the last "*", for example:
"prefix*suffix"
will now expand to
"prefix" + <RANDOM_VALUE> + "suffix"
RELNOTE=yes
Fixes #33805.
Change-Id: I85fa73ae6a684ce820d1810c82a60765eb9c4a42
Reviewed-on: https://go-review.googlesource.com/c/go/+/198488
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Dan Scales [Mon, 24 Jun 2019 19:59:22 +0000 (12:59 -0700)]
cmd/compile, cmd/link, runtime: make defers low-cost through inline code and extra funcdata
Generate inline code at defer time to save the args of defer calls to unique
(autotmp) stack slots, and generate inline code at exit time to check which defer
calls were made and make the associated function/method/interface calls. We
remember that a particular defer statement was reached by storing in the deferBits
variable (always stored on the stack). At exit time, we check the bits of the
deferBits variable to determine which defer function calls to make (in reverse
order). These low-cost defers are only used for functions where no defers
appear in loops. In addition, we don't do these low-cost defers if there are too
many defer statements or too many exits in a function (to limit code increase).
When a function uses open-coded defers, we produce extra
FUNCDATA_OpenCodedDeferInfo information that specifies the number of defers, and
for each defer, the stack slots where the closure and associated args have been
stored. The funcdata also includes the location of the deferBits variable.
Therefore, for panics, we can use this funcdata to determine exactly which defers
are active, and call the appropriate functions/methods/closures with the correct
arguments for each active defer.
In order to unwind the stack correctly after a recover(), we need to add an extra
code segment to functions with open-coded defers that simply calls deferreturn()
and returns. This segment is not reachable by the normal function, but is returned
to by the runtime during recovery. We set the liveness information of this
deferreturn() to be the same as the liveness at the first function call during the
last defer exit code (so all return values and all stack slots needed by the defer
calls will be live).
I needed to increase the stackguard constant from 880 to 896, because of a small
amount of new code in deferreturn().
The -N flag disables open-coded defers. '-d defer' prints out the kind of defer
being used at each defer statement (heap-allocated, stack-allocated, or
open-coded).
Cost of defer statement [ go test -run NONE -bench BenchmarkDefer$ runtime ]
With normal (stack-allocated) defers only: 35.4 ns/op
With open-coded defers: 5.6 ns/op
Cost of function call alone (remove defer keyword): 4.4 ns/op
Text size increase (including funcdata) for go cmd without/with open-coded defers: 0.09%
The average size increase (including funcdata) for only the functions that use
open-coded defers is 1.1%.
The cost of a panic followed by a recover got noticeably slower, since panic
processing now requires a scan of the stack for open-coded defer frames. This scan
is required, even if no frames are using open-coded defers:
Cost of panic and recover [ go test -run NONE -bench BenchmarkPanicRecover runtime ]
Without open-coded defers: 62.0 ns/op
With open-coded defers: 255 ns/op
A CGO Go-to-C-to-Go benchmark got noticeably faster because of open-coded defers:
CGO Go-to-C-to-Go benchmark [cd misc/cgo/test; go test -run NONE -bench BenchmarkCGoCallback ]
Without open-coded defers: 443 ns/op
With open-coded defers: 347 ns/op
Fazlul Shahriar [Wed, 16 Oct 2019 02:58:40 +0000 (22:58 -0400)]
net: fix multicast and IPv6 related issues on Plan 9
Fix issues that make these tests pass:
- TestDialerLocalAddr: return error if local address is not IPv4 for
"tcp4" network.
- TestInterfaceAddrs, TestInterfaceUnicastAddrs: don't assume each
interface has only one address. It may have more than one or none.
- TestConcurrentPreferGoResolversDial: should be skipped on Plan 9.
- TestListenMulticastUDP: remove IP from `announce` command and don't
mix IPv4 address with IPv6 address in `addmulti` command.
Than McIntosh [Mon, 14 Oct 2019 14:06:37 +0000 (10:06 -0400)]
[dev.link] cmd/link/internal/objfile: relocate loader to new package
Third change of several to update the loader API to reflect the final
consensus version of the loader API as described in Cherry's doc.
This piece:
- move objfile.Loader into its own separate package, and update
clients accordingly.
This includes a few minor cleanups, including converting a couple
of loader-related functions to methods, and privatizing some of the
loader methods such as ToGlobal/ToLocal.
Change-Id: Iae20585751a45491d8b19dcffc096aadae6bbfc6
Reviewed-on: https://go-review.googlesource.com/c/go/+/200998
Run-TryBot: Than McIntosh <thanm@google.com> Reviewed-by: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Agniva De Sarker [Sat, 12 Oct 2019 15:43:28 +0000 (21:13 +0530)]
cmd/internal/obj/wasm,cmd/link/internal/wasm: add fast path for writeUleb128
While building a simple hello world binary, there are total 858277 calls
to writeUleb during the assembler phase out of which 836625 (97%) are less than 7 bits.
Using a simple micro-benchmark like this:
func BenchmarkUleb(b *testing.B) {
var buf bytes.Buffer
for i := 0; i < b.N; i++ {
writeUleb128(&buf, 42)
buf.Reset()
}
}
We get the following results with the fast path enabled.
name old time/op new time/op delta
Uleb-4 8.45ns ± 2% 7.51ns ± 2% -11.16% (p=0.000 n=10+10)
Applying the time taken to the number of calls, we get roughly 6% improvement
in total time taken for writeUleb128.
We also apply the change to the function in linker to make it consistent.
Cherry Zhang [Tue, 15 Oct 2019 21:51:32 +0000 (17:51 -0400)]
cmd/compile: on Wasm and AIX, let deferred nil function panic at invocation
The Go spec requires
If a deferred function value evaluates to nil, execution
panics when the function is invoked, not when the "defer"
statement is executed.
On Wasm and AIX, currently we actually emit a nil check at the
point of defer statement, which will make it panic too early.
This CL fixes this.
Also, on Wasm, now the nil function will be passed through
deferreturn to jmpdefer, which does an explicit nil check and
calls sigpanic if it is nil. This sigpanic, being called from
assembly, is ABI0. So change the assembler backend to also
handle sigpanic in ABI0.
Robert Griesemer [Tue, 15 Oct 2019 20:44:22 +0000 (13:44 -0700)]
math/big: make Rat accessors safe for concurrent use
Do not modify the underlying Rat denominator when calling
one of the accessors Float32, Float64; verify that we don't
modify the Rat denominator when calling Inv, Sign, IsInt, Num.
Fixes #34919.
Reopens #33792.
Change-Id: Ife6d1252373f493a597398ee51e7b5695b708df5
Reviewed-on: https://go-review.googlesource.com/c/go/+/201205 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Cherry Zhang [Sat, 12 Oct 2019 05:05:03 +0000 (01:05 -0400)]
[dev.link] cmd/link: let cgo import overwrite contentless data symbol
A contentless data symbol may be a declaration of a cgo-imported
variable, e.g.
//go:cgo_import_dynamic xxx
var xxx uintptr
In this case, we want to mark the symbol imported, instead of
defined with zero value.
We used to load cgo directives before loading the object file, so
we'll mark the symbol SDYNIMPORT first. But in newobj mode,
currently we load cgo directives later. Letting SDYNIMPORT
overwrite contentless data symbol makes it work in both ordering.
Cherry Zhang [Fri, 11 Oct 2019 21:43:32 +0000 (17:43 -0400)]
[dev.link] cmd/link: add dupok symbols resolved to another package to textp
When a dupok symbol is resolved to another package, we still need
to record its presence in the current package, as the trampoline
pass expects packages are laid out in dependency order. At the
point after deadcode where we populate symbol contents for
reachable symbols (add relocations and read symbol data), make a
note of the dupok text symbols for each package. Later in
addToTextp we will visit packages in dependency order, process
the dup text symbol list for each package and select a final lib
for each dup text symbol.
Cherry Zhang [Tue, 8 Oct 2019 21:22:20 +0000 (17:22 -0400)]
[dev.link] cmd/internal/obj, cmd/link: add InlTree in new object files
Add InlTree to the FuncInfo aux symbol in new object files.
In the linker, change InlinedCall.Func from a Symbol to a string,
as we only use its Name. (There was a use of Func.File, but that
use is not correct anyway.) So we don't need to create a Symbol
if not necessary.
Cherry Zhang [Tue, 8 Oct 2019 19:35:36 +0000 (15:35 -0400)]
[dev.link] cmd/link: implement symbol overwrite logic
If two defined symbols have the same name, one contentless and
one with content, the one with content "wins". This is mainly for
go:linkname on data symbols. Support this logic in newobj mode.
Introduce an "overwrite" mechanism, letting one symbol overwrite
another. This machanism could later be used for the linker
overwriting symbol contents (e.g. -X flag).
Cherry Zhang [Tue, 8 Oct 2019 01:10:41 +0000 (21:10 -0400)]
[dev.link] cmd/internal/obj, cmd/link: use aux symbol for DWARF symbols
Use the auxiliary symbol mechanism to connect the text symbol and
its associated DWARF symbols. This way, the linker can track the
DWARF symbols from the text symbol, without looking up special
names.
Currently, in the linker this is only used in the deadcode pass
to track which DWARF symbols are used and need to load. Later
passes still use name lookup for now.
Cherry Zhang [Sat, 5 Oct 2019 02:05:41 +0000 (22:05 -0400)]
[dev.link] cmd/link: create sym.Symbols after deadcode in newobj mode
With the new object files, now we can run the deadcode pass on
indices instead of Symbol structs, so we can delay creating
Symbols after the deadcode pass. Then we only need to create
reachable symbols.
Not create Symbols in LoadNew and LoadRefs, and recombine
LoadReloc into LoadFull.
Split loadcgo into two parts: the first finds root symbols, the
second create Symbols and sets attributes. The first runs before
the deadcode pass, while the second runs after.
TODO: currently there are still symbols that are not marked
reachable but still used. This includes DWARF symbols, file
symbols, and type symbols that are referenced by DWARF symbols.
We still need to create them (conservatively).
Ian Lance Taylor [Tue, 15 Oct 2019 14:12:26 +0000 (07:12 -0700)]
time: avoid or clarify CEST
In the tzdata database CEST is not recognized as a timezone name.
It is used as the abbreviated name for daylight saving time in
Central Europe. Avoid using CEST in documentation as it suggests
that programs can parse dates that use CEST, which will typically
fail on Unix systems.
Updates #34913
Change-Id: I4b22f7d06607eb5b066812a48af58edd95498286
Reviewed-on: https://go-review.googlesource.com/c/go/+/201197
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Bryan C. Mills <bcmills@google.com>
Michael Anthony Knyszek [Mon, 14 Oct 2019 17:33:36 +0000 (17:33 +0000)]
runtime: call goready in wakeScavenger instead of ready
This changes fixes an oversight in wakeScavenger which would cause ready
to be called off of the system stack. This change makes it so that
wakeScavenger calls goready, which switches to the system stack before
calling ready.
Fixes #34773.
Change-Id: Icb13f180b4d8fdd47c921eac1b896e3dd49e43b3
Reviewed-on: https://go-review.googlesource.com/c/go/+/200999
Run-TryBot: Michael Knyszek <mknyszek@google.com> Reviewed-by: Keith Randall <khr@golang.org>
David Chase [Wed, 9 Oct 2019 22:06:06 +0000 (18:06 -0400)]
cmd/compile: preserve statements in late nilcheckelim optimization
When a subsequent load/store of a ptr makes the nil check of that pointer
unnecessary, if their lines differ, change the line of the load/store
to that of the nilcheck, and attempt to rehome the load/store position
instead.
This fix makes profiling less accurate in order to make panics more
informative.
Fixes #33724
Change-Id: Ib9afaac12fe0d0320aea1bf493617facc34034b3
Reviewed-on: https://go-review.googlesource.com/c/go/+/200197
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
Daniel Martí [Sun, 13 Oct 2019 21:33:18 +0000 (22:33 +0100)]
cmd/go: refuse -w with an invalid GO111MODULE
It was possible to get 'go env' to break itself:
$ go env -w GO111MODULE=bad
$ go env
go: unknown environment setting GO111MODULE=bad
We already check if the variable name is known. In some cases like
GO111MODULE, we also know what the variable's valid values are. Enforce
it when writing the variable, not just when fetching it.
Fixes #34880.
Change-Id: I10d682087c69f3445f314fd4473644f694e255f7
Reviewed-on: https://go-review.googlesource.com/c/go/+/200867
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Jay Conrod <jayconrod@google.com> Reviewed-by: Bryan C. Mills <bcmills@google.com>
Cherry Zhang [Wed, 9 Oct 2019 14:22:02 +0000 (10:22 -0400)]
[dev.link] cmd/internal/goobj2: separate Autolib from Pkglist in new object file
In CL 196030 we decided to combine the imported package list
(Autolib) and referenced package list (PkgIdx, or Pkglist).
However, in some cases the Autolib list may contain file name,
instead of package path, e.g.
https://go.googlesource.com/go/+/refs/heads/dev.link/src/cmd/compile/internal/gc/main.go#1181
And the linker needs that to locate the file. This mostly happens
with direct invocation of the compiler and linker (i.e., not
through "go build").
Instead of letting the linker make guess of the file name based
on the package path, make Autolib a separate list.
Giovanni Bajo [Sat, 12 Oct 2019 23:30:51 +0000 (01:30 +0200)]
cmd/compile: in poset, change the way inequality is recorded
Before this CL, inequality was recorded in a bit matrix using
SSA IDs. This allowed to record inequality for SSA values that
we didn't know any relation in the partial order of. Unfortunately,
this also means that inequality is harder to use within the poset
itself as there is not fast way to map from internal poset indices
and SSA values.
Since we will need to check for inequality in following CLs within
code that lost track of SSA values, switch to use a bit matrix
of poset indices instead. This requires always allocate a poset
node (as a new root) for values that are first seen in a SetNonEqual
call, but it doesn't sound like a big problem. The other solution
(creating and maintaining a reverse map from poset indices to SSA
values) seem more complicated and memory hungry.
Change-Id: Ic917485abbe70aef7ad6fa98408e5430328b6cd9
Reviewed-on: https://go-review.googlesource.com/c/go/+/196782
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: David Chase <drchase@google.com>
Giovanni Bajo [Sat, 21 Sep 2019 23:26:50 +0000 (01:26 +0200)]
cmd/compile: in poset, make constant handling more flexible
Currently, constants in posets, in addition to being stored in
a DAG, are also stored as SSA values in a slice. This allows to
quickly go through all stored constants, but it's not easy to search
for a specific constant.
Following CLs will benefit from being able to quickly find
a constants by value in the poset, so change the constants
structure to a map. Since we're at it, don't store it as
*ssa.Value: poset always uses dense uint32 indices when
referring a node, so just switch to it.
Using a map also forces us to have a single node per
constant value: this is a good thing in the first place,
so this CL also make sure we never create two nodes for
the same constant value.
Change-Id: I099814578af35f935ebf14bc4767d607021f5f8b
Reviewed-on: https://go-review.googlesource.com/c/go/+/196781
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: David Chase <drchase@google.com>
Giovanni Bajo [Sat, 21 Sep 2019 23:34:13 +0000 (01:34 +0200)]
cmd/compile: add debugging mode for poset
Add an internal mode to simplify debugging of posets
by checking the integrity after every mutation. Turn
it on within SSA checked builds.
Change-Id: Idaa8277f58e5bce3753702e212cea4d698de30ca
Reviewed-on: https://go-review.googlesource.com/c/go/+/196780
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: David Chase <drchase@google.com>
Emmanuel T Odeke [Sat, 12 Oct 2019 00:27:33 +0000 (20:27 -0400)]
net/http: fix and lock-in Client.Do docs on request cancelation
Fixes the docs to correctly match the implementation
and also adds a test locking-in the behavior to prevent
any accidental future regressions on the docs.
Matthew Dempsky [Sat, 12 Oct 2019 23:21:55 +0000 (16:21 -0700)]
cmd/compile: move some ONAME-specific flags from Node to Name
The IsClosureVar, IsOutputParamHeapAddr, Assigned, Addrtaken,
InlFormal, and InlLocal flags are only interesting for ONAME nodes, so
it's better to set these flags on Name.flags instead of Node.flags.
Two caveats though:
1. Previously, we would set Assigned and Addrtaken on the entire
expression tree involved in an assignment or addressing operation.
However, the rest of the compiler only actually cares about knowing
whether the underlying ONAME (if any) was assigned/addressed.
2. This actually requires bumping Name.flags from bitset8 to bitset16,
whereas it doesn't allow shrinking Node.flags any. However, Name has
some trailing padding bytes, so expanding Name.flags doesn't cost any
memory.
Emmanuel T Odeke [Sun, 13 Oct 2019 22:07:06 +0000 (15:07 -0700)]
net/http: fix Transport panic with nil Request.Header
For Go 1.13 we introduced Header.Clone and it returns
nil if a nil Header is cloned. Unfortunately, though,
this exported Header.Clone nil behavior differed from
the old Go 1.12 and earlier internal header clone
behavior which always returned non-nil Headers.
This CL fixes the places where that distinction mattered.
Cherry Zhang [Sat, 12 Oct 2019 01:51:01 +0000 (21:51 -0400)]
[dev.link] cmd/link: on AIX, use relocation to locate target symbol from TOC symbol
On AIX, a TOC symbol always has a relocation to its target symbol.
Instead of using name lookup to locate the target symbol, we can
just use the relocation.
Using name lookup, besides being less efficient, needs to provide
the right symbol version. In this particular case, we are looking
for a data symbol so it is almost always version 0. But in case
that it is a text symbol, we may get an ABIALIAS symbol, which
does not have its Sect set.
Cherry Zhang [Sat, 12 Oct 2019 05:07:31 +0000 (01:07 -0400)]
[dev.link] cmd/internal/obj: sort ctxt.Data on AIX
On AIX, TOC symbols may be created and added to ctxt.Data
concurrently. To ensure reproducible builds, sort ctxt.Data.
This implements the same logic as WriteObjFile does for old
object files.
Cherry Zhang [Tue, 8 Oct 2019 22:21:22 +0000 (18:21 -0400)]
[dev.link] cmd/link: support reflect.Type.Method tracking in deadcode2
When reflect.Type.Method is called, all exported methods from a
reachable type need to be conservatively live. When such a
function is called, the compiler sets an attribute to the
function, and the linker needs to check that attribute. Implement
this in the index-based deadcode pass.
Unify symbol flags and FuncInfo flags to make things simpler. In
particular, the deadcode pass can check the reflectMethod
attribute without reading in and decoding FuncInfo.
Agniva De Sarker [Sun, 13 Oct 2019 15:03:47 +0000 (20:33 +0530)]
cmd/go/internal/work: fix error while passing custom vet tool
For GOROOT packages, we were adding -unsafeptr=false to prevent unsafe.Pointer
checks. But the flag also got passed to invocations of go vet with a custom
vet tool. To prevent this from happening, we add this flag only when no
tools are passed.
Fixes #34053
Change-Id: I8bcd637fd8ec423d597fcdab2a0ceedd20786019
Reviewed-on: https://go-review.googlesource.com/c/go/+/200957
Run-TryBot: Agniva De Sarker <agniva.quicksilver@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Jay Conrod <jayconrod@google.com>
Matthew Dempsky [Sat, 12 Oct 2019 23:05:34 +0000 (16:05 -0700)]
cmd/compile: remove Addable flag
This flag is supposed to indicate whether the expression is
"addressable"; but in practice, we infer this from other
attributes about the expression (e.g., n.Op and n.Class()).