Fixes #4470.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6949073

Replacement for GOEXPERIMENT=zerostack, easier to use.
Does not require a separate toolchain.

R=ken2
CC=golang-dev
https://golang.org/cl/6996051

remove zerostack compiler experiment; will do at link time instead

««« original CL description
cmd/gc: add GOEXPERIMENT=zerostack to clear stack on function entry

This is expensive but it might be useful in cases where
people are suffering from false positives during garbage
collection and are willing to trade the CPU time for getting
rid of the false positives.

On the other hand it only eliminates false positives caused
by other function calls, not false positives caused by dead
temporaries stored in the current function call.

The 5g/6g/8g changes were pulled out of the history, from
the last time we needed to do this (to work around a goto bug).
The code in go.h, lex.c, pgen.c is new but tiny.

R=ken2
CC=golang-dev
https://golang.org/cl/6938073
»»»

R=ken2
CC=golang-dev
https://golang.org/cl/7002051

When using subexpressions ($1) as replacements, when they either don't exist or values weren't found causes a panic.
This patch ensures that the match location isn't -1, to prevent out of bounds errors.
Fixes #3816.

R=franciscossouza, rsc
CC=golang-dev
https://golang.org/cl/6931049

Generated by addca.

R=gobot
CC=golang-dev
https://golang.org/cl/7007051

EDE2 is a rare DES mode that can be implemented with crypto/des, but
it's somewhat non-obvious so this CL adds an example of doing so.

Fixes #3537.

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/6721056

Fixes #4579.

R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/7000051

Fixes #4562.

R=ken2
CC=golang-dev
https://golang.org/cl/7008044

Fixes #3559.

This makes Marshal handle fields marked ",any" instead of ignoring
them. That makes Marshal more symmetrical with Unmarshal, which seems
to have been a design goal.

Note some test cases were changed, because this patch changes
marshalling behavior. I think the previous behavior was buggy, but
there's still a backward-compatibility question to consider.

R=rsc
CC=golang-dev, n13m3y3r
https://golang.org/cl/6938068

R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/7003049

Also restore the smallintconst case for binary ops.

Fixes #3835.

R=daniel.morsing, rsc
CC=golang-dev
https://golang.org/cl/6999043

Most benchmarks are within the 3% margin of error. This code path is quite common in the fmt package.

linux/arm, Freescale iMX.53 (cortex-a8)

fmt:
benchmark                      old ns/op    new ns/op    delta
BenchmarkSprintfEmpty                925          785  -15.14%
BenchmarkSprintfString              5050         5039   -0.22%
BenchmarkSprintfInt                 4425         4406   -0.43%
BenchmarkSprintfIntInt              5802         5762   -0.69%
BenchmarkSprintfPrefixedInt         7029         6541   -6.94%
BenchmarkSprintfFloat              10278        10083   -1.90%
BenchmarkManyArgs                  18558        17606   -5.13%
BenchmarkScanInts               15592690     15415360   -1.14%
BenchmarkScanRecursiveInt       25155020     25050900   -0.41%

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6921056

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6996046

Taken from upstream pprof.

Fixes #4564.

R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/6952045

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6997043

Fixes #4557.

R=dave, rsc
CC=golang-dev
https://golang.org/cl/6946078

This disables checks for limited address space
and unlimited stack. They are not required for Go.
Fixes #4577.

R=golang-dev, iant
CC=golang-dev, kamil.kisiel, minux.ma
https://golang.org/cl/7003045

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7006043

Avoids unlink the underlying file before the socket close.

R=golang-dev, dave
CC=golang-dev
https://golang.org/cl/7004044

R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/6944066

Followup to 6971049.

R=bradfitz
CC=golang-dev
https://golang.org/cl/6970049

Fixes #4580.

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/7002043

A fatal error used to happen when escassign-ing a multiple
function return to a single node. However, the situation
naturally appears when using "go f(g())" or "defer f(g())",
because g() is escassign-ed to sink.

Fixes #4529.

R=golang-dev, lvd, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6920060

Fixes #4309.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6974045

Fixes #4543.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6971050

This guarantees that powers of two return exact answers.

We could do a multiprecision approximation for the
rest of the answer too, but this seems like it should be
good enough.

Fixes #4567.

R=golang-dev, iant, remyoudompheng
CC=golang-dev
https://golang.org/cl/6943074

Enable cgo on OpenBSD.

The OpenBSD ld.so(1) does not currently support PT_TLS sections. Work
around this by fixing up the TCB that has been provided by librthread
and reallocating a TCB with additional space for TLS. Also provide a
wrapper for pthread_create, allowing zeroed TLS to be allocated for
threads created externally to Go.

Joint work with Shenghou Ma (minux).

Requires change 6846064.

Fixes #3205.

R=golang-dev, minux.ma, iant, rsc, iant
CC=golang-dev
https://golang.org/cl/6853059

The OpenBSD ld.so(1) does not currently support PT_TLS and refuses
to load ELF binaries that contain PT_TLS sections. Do not emit PT_TLS
sections - we will handle this appropriately in runtime/cgo instead.

R=golang-dev, minux.ma, iant
CC=golang-dev
https://golang.org/cl/6846064

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6968049

Fixes #4550.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6973048

If a handler did a panic(nil), the connection was never closed.

Fixes #4050

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/6971049

Fixes #4345.

Benchmarks are promising,

benchmark         old ns/op    new ns/op    delta
BenchmarkPrint     14716391     14747131   +0.21%

benchmark         old ns/op    new ns/op    delta
BenchmarkParse      8846219      8809343   -0.42%

benchmark          old MB/s     new MB/s  speedup
BenchmarkParse         6.61         6.64    1.00x

Also includes additional tests to improve token.FileSet coverage.

R=dvyukov, gri
CC=golang-dev
https://golang.org/cl/6968044

Update #4354.

Add a test to expose the race in the FileSet position cache.

R=dvyukov, gri
CC=fullung, golang-dev
https://golang.org/cl/6940078

R=golang-dev, agl, iant
CC=golang-dev
https://golang.org/cl/6955043

caught by https://github.com/lyda/misspell-check.

R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/6949072

cmd/go: pass gccgoflags at the end of gccgo command line, warn if user passes the wrong toolchain options

R=iant
CC=golang-dev
https://golang.org/cl/6940082

runtime: use "mp" and "gp" instead of "m" and "g" for local variable name to avoid confusion with the global "m" and "g".

R=golang-dev, minux.ma, rsc
CC=bradfitz, golang-dev
https://golang.org/cl/6939064

Generated by addca.

R=gobot
CC=golang-dev
https://golang.org/cl/6945079

For CL 6853059.

R=jsing, rsc
CC=golang-dev
https://golang.org/cl/6938076

For Linux/{386,arm}, FreeBSD/{386,amd64,arm}, NetBSD/{386,amd64}, OpenBSD/{386,amd64}.
Note: our Darwin implementation already has ns resolution.

Linux/386 (Core i7-2600 @ 3.40GHz, kernel 3.5.2-gentoo)
benchmark       old ns/op    new ns/op    delta
BenchmarkNow          110          118   +7.27%

Linux/ARM (ARM Cortex-A8 @ 800MHz, kernel 2.6.32.28 android)
benchmark       old ns/op    new ns/op    delta
BenchmarkNow          625          542  -13.28%

Linux/ARM (ARM Cortex-A9 @ 1GHz, Pandaboard)
benchmark       old ns/op    new ns/op    delta
BenchmarkNow          992          909   -8.37%

FreeBSD 9-REL-p1/amd64 (Dell R610 Server with Xeon X5650 @ 2.67GHz)
benchmark       old ns/op    new ns/op    delta
BenchmarkNow          699          695   -0.57%

FreeBSD 9-REL-p1/amd64 (Atom D525 @ 1.80GHz)
benchmark       old ns/op    new ns/op    delta
BenchmarkNow         1553         1658   +6.76%

OpenBSD/amd64 (Dell E6410 with i5 CPU M 540 @ 2.53GHz)
benchmark       old ns/op    new ns/op    delta
BenchmarkNow         1262         1236   -2.06%

OpenBSD/i386 (Asus eeePC 701 with Intel Celeron M 900MHz - locked to 631MHz)
benchmark       old ns/op    new ns/op    delta
BenchmarkNow         5089         5043   -0.90%

NetBSD/i386 (VMware VM with Core i5 CPU @ 2.7GHz)
benchmark       old ns/op    new ns/op    delta
BenchmarkNow          277          278   +0.36%

NetBSD/amd64 (VMware VM with Core i5 CPU @ 2.7Ghz)
benchmark       old ns/op    new ns/op    delta
BenchmarkNow          103          105   +1.94%

Thanks Maxim Khitrov, Joel Sing, and Dave Cheney for providing benchmark data.

R=jsing, dave, rsc
CC=golang-dev
https://golang.org/cl/6820120