This reverts commit bd837745.

Reason for revert: This broke ELF layout on arm, arm64, mips*, mips64*, ppc64*, and s390x.

Change-Id: I56a27b76e6f4b22ce39a99790af9116f8687eee9
Reviewed-on: https://go-review.googlesource.com/118675Reviewed-by: Heschi Kreinick <heschi@google.com>
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #25852

Change-Id: I35c630367c8f1934dcffc0b0e08891d55a903518
Reviewed-on: https://go-review.googlesource.com/118560
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Bonventre <andybons@golang.org>

Like on other architectures, use rawSyscallNoError for Linux syscalls
that don't return an error and convert all applicable occurences of
RawSyscall to use it instead.

This was missed in CL 84485 because mkall.sh doesn't support
mipsx/mips64x, so add the corresponding entries as well.

Updates #22924

Change-Id: I762cbee0827140b9890c4a10830e0b4cd33de92f
Reviewed-on: https://go-review.googlesource.com/118655
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This commit changes wasm_exec.js to not depend on the existence of
performance.timeOrigin. The field is not yet supported on all
browsers, e.g. it is unavailable on Safari.

Change-Id: I6cd3834376c1c55424c29166fde1219f0d4d338f
Reviewed-on: https://go-review.googlesource.com/118617Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The pprof tool utilizes attributes of mapping entries
such as HasFunctions to determine whether the profile
includes necessary symbol information.
If none of the attributes is set, pprof tool tries to
read the corresponding binary to use for local symbolization.
If the binary doesn't exist, it prints out error messages.

Go runtime generated profiles without any of the attributes
set so the pprof tool always printed out the error messages.
The error messages became more obvious with the new
terminal support that uses red color for error messages.

Go runtime can symbolize all Go symbols and generate
self-contained profile for pure Go program. Thus, there
is no reason for the pprof tool to look for the copy of
the binary. So, this CL sets one of the attributes
(HasFunctions) true if all PCs in samples look fully
symbolized.

For non-pure Go program, however, it's possible that
symbolization of non-Go PCs is incomplete. In this case,
we need to leave the attributes all false so pprof can attempt
to symbolize using the local copy of the binary if available.
It's hard to determine whether a mapping includes non-Go
code. Instead, this CL checks PCs from collected samples.
If unsuccessful symbolization is observed, it skips setting
the HasFunctions attribute.

Fixes #25743

Change-Id: I5108be45bbc37ab486d145fa03e7ce37d88fad50
Reviewed-on: https://go-review.googlesource.com/118275
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This is needed in addition to CL 110066 in order to be able to generate
Go type definitions for linux/riscv64 in the golang.org/x/sys/unix
package.

Change-Id: I4a27e6424aaea63283b55bd4f73b958b41f29d72
Reviewed-on: https://go-review.googlesource.com/118618
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

CL 108156 added -cgo and -export,
but in the usage line it added -cgo and -list.
CL 117015 correctly added -export to the usage line.
All that remains is to remove -list.

Change-Id: I8cc5cfc78bc6b52080ae1b861f92620a8f18b53f
Reviewed-on: https://go-review.googlesource.com/118375
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I9d2d25df067ca573589db5ff18296a5ec33866be
Reviewed-on: https://go-review.googlesource.com/118595Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I3ac25cf1770b5ac0d36690c37615b3badd27463d
Reviewed-on: https://go-review.googlesource.com/118455Reviewed-by: Rob Pike <r@golang.org>

Change-Id: Iea5c705dd58f9b83fbeb0500defcc08c34716169
GitHub-Last-Rev: 35702c784e2329fe3e44947430d246f8cdb04645
GitHub-Pull-Request: golang/go#25858
Reviewed-on: https://go-review.googlesource.com/118536Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Separated out panic handling for bimporter and importer so that
the handler can consider the current version and report a better
error.

Added new export data test for export data version 999 (created
by changing the compiler temporarily) and verifying expected
error message.

Fixes #25856.

Change-Id: Iaafec07b79499154ef7c007341783fa07c57f24d
Reviewed-on: https://go-review.googlesource.com/118496
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

In an effort to help others avoid the issues I've hit due to lack of
symlink support under GOPATH, I've added a note of warning to the
Workspaces section.

I have not changed the contents of go help gopath, because on reflection
it seems this change alone may be sufficient.

Fixes #21320

Change-Id: Ib8969bf12cecad878e89ff66b5864bbf3caaf219
Reviewed-on: https://go-review.googlesource.com/61930Reviewed-by: Ian Lance Taylor <iant@golang.org>

name              old time/op   new time/op   delta
EncodeToString-4   35.5µs ± 7%   33.3µs ± 6%  -6.27%   (p=0.008 n=10+9)
DecodeString-4      120µs ± 7%    113µs ± 8%  -5.88%  (p=0.011 n=10+10)

name              old speed     new speed     delta
EncodeToString-4  231MB/s ± 8%  247MB/s ± 5%  +6.55%   (p=0.008 n=10+9)
DecodeString-4    109MB/s ± 7%  116MB/s ± 8%  +6.27%  (p=0.011 n=10+10)

Change-Id: I60bf962464179e35b1711617adbc45a822eaece5
Reviewed-on: https://go-review.googlesource.com/45876Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I0bbb53cad9a7c464ab1cfca381128f33496813ff
Reviewed-on: https://go-review.googlesource.com/49130Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I3a83c63f4db2e46fd96f373378a429896e93f9d1
Reviewed-on: https://go-review.googlesource.com/48861Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This commit changes sys.Wasm to sys.WASM, as requested on
https://groups.google.com/forum/#!topic/golang-dev/VquDxlhjPkg

Change-Id: I30a208c34576a8bb49b9beb524203d71df8fdf1c
Reviewed-on: https://go-review.googlesource.com/118395Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Currently these two forms of layout are done in a single pass. This
makes it difficult to compress DWARF sections because that must be
done after relocations are applied, which must happen after virtual
address layout, but we can't layout the file until we've compressed
the DWARF sections.

Fix this by separating the two layout steps. In the process, we can
also unify the copy-pasted code in Link.address to compute file
offsets. Currently, each instance of this is slightly different, but
there's no reason for it to be. For example, we don't perform
PEFILEALIGN alignment on Segrodata or Selreltodata even when HeadType
== Hwindows, but it turns out it doesn't matter whether you do or
don't because these segments simply don't exist on Windows. Hence, in
the unified code path, we do this alignment for all segments.
Likewise, there are two ways of computing Fileoff:
  seg.Vaddr - prev.Vaddr + prev.Fileoff
and
  prev.Fileoff + uint64(Rnd(int64(prev.Filelen), int64(*FlagRound)))
At the moment, these always have the same value, but the latter will
continue to work after we start compressing sections on disk.

Tested by comparing test binaries for all packages in std before and
after this change for GOOS={linux,windows,darwin,plan9}. All binaries
are identical.

For #11799.

Change-Id: If09f28771bb4d78dd392fd58b8d7c9d5f22b0b9f
Reviewed-on: https://go-review.googlesource.com/111682
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Before this CL, if you had GOCACHE=/some/dir, then the cmd/go tests used it.
But if you were relying on the implicit behavior that GOCACHE being empty
meant an appropriate system-specific cache directory, then the cmd/go tests
ran with no cache at all, which makes them about 4X slower.

During all.bash GOCACHE is set to a fresh temporary directory and is therefore
already getting proper caching; this CL mainly helps people running 'go test cmd/go'
by hand.

Change-Id: I7c322ca79b877c1d0a3b448b95d5354fbfcba7f8
Reviewed-on: https://go-review.googlesource.com/118320
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

ARM64 manual says it is "constrained unpredictable" if the src
and dst registers of STLXRB are same, although it doesn't seem
to cause any problem on real hardwares so far. Fix by allocating
a different register to hold the updated value for
AtomicAnd8/Or8. We do this by making the ops returns <val,mem>
like AtomicAdd, although val will not be used elsewhere.

Fixes #25823.

Change-Id: I735b9822f99877b3c7aee67a65e62b7278dc40df
Reviewed-on: https://go-review.googlesource.com/117976
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Wei Xiao <Wei.Xiao@arm.com>

Fixes #25834

Change-Id: I33e58dabfd04b84dfee1a9a3796796b5d19862e7
Reviewed-on: https://go-review.googlesource.com/118295
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

The original fix (https://go-review.googlesource.com/c/go/+/35831)
for this issue was incorrect as it reported cycles in cases where
it shouldn't.

Instead, use a different approach: A type cycle containing aliases
is only a cycle if there are no type definitions. As soon as there
is a type definition, alias expansion terminates and there is no
cycle.

Approach: Split sprint_depchain into two non-recursive and more
easily understandable functions (cycleFor and cycleTrace),
and use those instead for cycle reporting. Analyze the cycle
returned by cycleFor before issueing an alias cycle error.

Also: Removed original fix (main.go) which introduced a separate
crash (#23823).

Fixes #18640.
Fixes #23823.
Fixes #24939.

Change-Id: Ic3707a9dec40a71dc928a3e49b4868c5fac3d3b7
Reviewed-on: https://go-review.googlesource.com/118078Reviewed-by: Matthew Dempsky <mdempsky@google.com>

Updates golang/go#23122

Change-Id: I2d6769101cdd580901cb08a3027d787fa438d4bc
Reviewed-on: https://go-review.googlesource.com/117975Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Also:
 - Add extra SystemStack space for darwin/arm64 just
like for darwin/arm.
 - Removed redundant stack alignment; the arm64 hardware enforces
 the 16 byte alignment.
 - Save and restore the g registers at library initialization.
 - Zero g registers since libpreinit can call libc functions
 that in turn use asmcgocall. asmcgocall requires an initialized g.
 - Change asmcgocall to work even if no g is set. The change mimics
 amd64.

Change-Id: I1b8c63b07cfec23b909c0d215b50dc229f8adbc8
Reviewed-on: https://go-review.googlesource.com/117176
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

sigaction, sigprocmask, sigaltstack, and raiseproc.

Fix bug in mstart_stub where we weren't saving callee-saved registers,
so if an m finished the pthread library calling mstart_stub would
sometimes fail.

Update #17490
Update #22805

Change-Id: Ie297ede0997910aa956834e49e85711b90cdfaa7
Reviewed-on: https://go-review.googlesource.com/116875
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Previously, go/doc would only consider functions and slices that
return types of T or any number of pointers to T: *T, **T, etc. This
change expands the definition of a constructor to include functions
that return arrays of a type (or pointer to that type) in its first
return.

With this change, the following return types also classify a function
as a constructor of type T:

[1]T
[1]*T
[1]**T
(and so on)

Fixes #22856.

Change-Id: I37957c5f2d6a7b2ceeb3fbaef359057f2039393d
Reviewed-on: https://go-review.googlesource.com/85355
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

Change-Id: I5704a07375fc672ac70c1f4e8df6f4fff760b4bf
Reviewed-on: https://go-review.googlesource.com/118117
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Change-Id: I88855dfa3166e90386c90bf6220be0596dab3c0d
Reviewed-on: https://go-review.googlesource.com/118175Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I67aac387359378cf7aa8f7cafa6557ebf1338baf
Reviewed-on: https://go-review.googlesource.com/118176Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Previously the Transport had good support for 100 Continue responses,
but other 1xx informational responses were returned as-is.

But per https://tools.ietf.org/html/rfc7231#section-6.2:

> A client MUST be able to parse one or more 1xx responses received
> prior to a final response, even if the client does not expect one. A
> user agent MAY ignore unexpected 1xx responses.

We weren't doing that. Instead, we were returning any 1xx that wasn't
100 as the final result.

With this change we instead loop over up to 5 (arbitrary) 1xx
responses until we find the final one, returning an error if there's
more than 5. The limit is just there to guard against malicious
servers and to have _some_ limit.

By default we ignore the 1xx responses, unless the user defines the
new httptrace.ClientTrace.Got1xxResponse hook, which is an expanded
version of the previous ClientTrace.Got100Continue.

Still remaining:

* httputil.ReverseProxy work. (From rfc7231#section-6.2: "A proxy MUST
  forward 1xx responses unless the proxy itself requested the
  generation of the 1xx response."). Which would require:

* Support for an http.Handler to generate 1xx informational responses.

Those can happen later. Fixing the Transport to be resilient to others
using 1xx in the future without negotiation (as is being discussed
with HTTP status 103) is most important for now.

Updates #17739

Change-Id: I55aae8cd978164643fccb9862cd60a230e430486
Reviewed-on: https://go-review.googlesource.com/116855
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

On dragonfly, freebsd and solaris the sendfile syscall does not update
the read position of the source fd. Update it after sendfile so
successive calls start at the correct position.

Fixes #25809

Change-Id: Iaac79f89704b75b8038d4bb60eaf793a262cdd8f
Reviewed-on: https://go-review.googlesource.com/117895
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I4e339b7c359a7cdb0933f7624ce190086c9c3599
Reviewed-on: https://go-review.googlesource.com/118155Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>

Setting GOROOT is no longer necessary for custom installation as of 1.10 (reference: https://go-review.googlesource.com/c/go/+/42533). Fixes #25002

Change-Id: Ic3980833ac437b7a20b951df33805ad1071a40ce
GitHub-Last-Rev: 156bf6510a21266bfb8397e564635278aa3bb1e5
GitHub-Pull-Request: golang/go#25190
Reviewed-on: https://go-review.googlesource.com/110435Reviewed-by: Ian Lance Taylor <iant@golang.org>

This CL takes advantage of the ability to record vet-specific export data,
added in CL 108558, to save information about observed printf wrappers.
Then calls to those wrappers from other packages can be format-checked.
This found a few real mistakes using previously-unrecognized printf
wrappers in cmd/compile. It will no doubt find real mistakes in external code.

Change-Id: I9c29c92d89bbdc984571a174a96e6054585e9cd4
Reviewed-on: https://go-review.googlesource.com/108559
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>

Updates #23445

Change-Id: I4b09073e53b1cf04de698b711fb5fb0d08bc02df
Reviewed-on: https://go-review.googlesource.com/118077Reviewed-by: Ian Lance Taylor <iant@golang.org>

This CL makes it possible for vet to write down notes about one package
and then access those notes later, when analyzing other code importing
that package. This is much like what the compiler does with its own export
data for type-checking, so we call it "vet-export" data or vetx data.

The next CL in the stack makes vet actually use this functionality.

Change-Id: Ic70043ab407dfbfdb3f30eaea7c0e3c8197009cf
Reviewed-on: https://go-review.googlesource.com/108558
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>

Fixes #25827

Change-Id: I6736c3ac061ca32aac2eb68b01ba53a179d68cf4
Reviewed-on: https://go-review.googlesource.com/118076
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

Keep searching for a package that is both findable and importable. The
current code would always guarantee that a package was findable but
exited if it was not importable.

Fixes #25478

Change-Id: I237b7dfafb930cae02538c4a2e4d5ce0c1058478
Reviewed-on: https://go-review.googlesource.com/114295Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

For memmove/memclr using jump tables only reduces overall
function performance for both amd64 and 386.

Benchmarks for 32-bit memclr:

	name            old time/op    new time/op    delta
	Memclr/5-8        8.01ns ± 0%    8.94ns ± 2%  +11.59%  (p=0.000 n=9+9)
	Memclr/16-8       9.05ns ± 0%    9.49ns ± 0%   +4.81%  (p=0.000 n=8+8)
	Memclr/64-8       9.15ns ± 0%    9.49ns ± 0%   +3.76%  (p=0.000 n=9+10)
	Memclr/256-8      16.6ns ± 0%    16.6ns ± 0%     ~     (p=1.140 n=10+9)
	Memclr/4096-8      179ns ± 0%     166ns ± 0%   -7.26%  (p=0.000 n=9+8)
	Memclr/65536-8    3.36µs ± 1%    3.31µs ± 1%   -1.48%  (p=0.000 n=10+9)
	Memclr/1M-8       59.5µs ± 3%    60.5µs ± 2%   +1.67%  (p=0.009 n=10+10)
	Memclr/4M-8        239µs ± 3%     245µs ± 0%   +2.49%  (p=0.004 n=10+8)
	Memclr/8M-8        618µs ± 2%     614µs ± 1%     ~     (p=0.315 n=10+8)
	Memclr/16M-8      1.49ms ± 2%    1.47ms ± 1%   -1.11%  (p=0.029 n=10+10)
	Memclr/64M-8      7.06ms ± 1%    7.05ms ± 0%     ~     (p=0.573 n=10+8)
	[Geo mean]        3.36µs         3.39µs        +1.14%

For less predictable data, like loop iteration dependant sizes,
branch table still shows 2-5% worse results.
It also makes code slightly more complicated.

This CL removes TODO note that directly suggest trying this
optimization out. That encourages people to spend their time
in a quite hopeless endeavour.

The code used to implement branch table used a 32/64-entry table
with pointers to TEXT blocks that implemented every associated
label work. Most last entries point to "loop" code that is
a fallthrough for all other sizes that do not map into specialized
routines. The only inefficiency is extra MOVL/MOVQ required
to fetch table pointer itself as MOVL $sym<>(SB)(AX*4) is not valid
in Go asm (it works in other assemblers):

	TEXT ·memclrNew(SB), NOSPLIT, $0-8
        	MOVL    ptr+0(FP), DI
        	MOVL    n+4(FP), BX
        	// Handle 0 separately.
        	TESTL   BX, BX
        	JEQ     _0
        	LEAL    -1(BX), CX // n-1
        	BSRL    CX, CX
		// AX or X0 zeroed inside every text block.
       		MOVL    $memclrTable<>(SB), AX
        	JMP     (AX)(CX*4)
	_0:
        	RET

Change-Id: I4f706931b8127f85a8439b95834d5c2485a5d1bf
Reviewed-on: https://go-review.googlesource.com/115678
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

CL 115975 changed TestGoExec to check symbol types.
However, this test is failing on Plan 9, because
there is no read-only data segment symbol on Plan 9.

This change fixes TestGoExec to replace the check
of read-only data segment symbol (R) by data segment
symbol (D) on Plan 9.

Fixes #25820.

Change-Id: I7164cd9056fa1dfcd1dc1b0f87653290c14c85fa
Reviewed-on: https://go-review.googlesource.com/118035
Run-TryBot: David du Colombier <0intro@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Currently .DepOnly is set when go list -test is invoked to help
distinguish those packages that matched the command line spec from those
which are dependencies (of test packages). This is also useful when
calling go list -deps for the same reason.

Change-Id: Ifc0e68dad0fd01355928793ef803691dee5f4f29
Reviewed-on: https://go-review.googlesource.com/112755
Run-TryBot: Paul Jolly <paul@myitcv.org.uk>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>