Fixes #4070.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/7004050

Before this CL, defining the variable worked fine, but then when
the implicit package-level init func was created, that caused a
name collision and a confusing error about the redeclaration.

Also add a test for issue 3705 (func init() needs body).

Fixes #4517.

R=ken2
CC=golang-dev
https://golang.org/cl/7008045

R=remyoudompheng
CC=golang-dev
https://golang.org/cl/7002052

An error during the compilation can be more precise
than an error at link time.

For 'func init', the error happens always: you can't forward
declare an init func because the name gets mangled.

For other funcs, the error happens only with the special
(and never used by hand) -= flag, which tells 6g the
package is pure go.

The go command now passes -= for pure Go packages.

Fixes #3705.

R=ken2
CC=golang-dev
https://golang.org/cl/6996054

Ordinary variable load was assumed to be not worth saving,
but not if one of the function calls later might change
its value.

Fixes #4313.

R=ken2
CC=golang-dev
https://golang.org/cl/6997047

The array skips the first TOKSTART entries.

Fixes #4410.

R=golang-dev, ken2, ken
CC=golang-dev
https://golang.org/cl/6999054

Fixes #3996.

R=ken2
CC=golang-dev
https://golang.org/cl/7001052

When we release memory to the OS, if the OS doesn't want us
to release it (for example, because the program executed
mlockall(MCL_FUTURE)), madvise will fail. Ignore the failure
instead of crashing.

Fixes #3435.

R=ken2
CC=golang-dev
https://golang.org/cl/6998052

benchmark             old ns/op    new ns/op    delta
BenchmarkDefer              165          113  -31.52%
BenchmarkDefer10            155          103  -33.55%
BenchmarkDeferMany          216          158  -26.85%

benchmark            old allocs   new allocs    delta
BenchmarkDefer                1            0  -100.00%
BenchmarkDefer10              1            0  -100.00%
BenchmarkDeferMany            1            0  -100.00%

benchmark             old bytes    new bytes    delta
BenchmarkDefer               64            0  -100.00%
BenchmarkDefer10             64            0  -100.00%
BenchmarkDeferMany           64           66    3.12%

Fixes #2364.

R=ken2
CC=golang-dev
https://golang.org/cl/7001051

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6971048

Close the read side of the pipe.
Fixes #4551.

R=rsc
CC=golang-dev
https://golang.org/cl/6962049

Fixes #3887.

R=golang-dev, daniel.morsing, remyoudompheng, rsc
CC=golang-dev
https://golang.org/cl/6997045

Fixes #4581.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/7000052

Any flag.Value that has an IsBoolFlag method that returns true
will be treated as a bool flag type during parsing.

Fixes #4262.

R=bradfitz, rsc
CC=golang-dev
https://golang.org/cl/6944064

The patch makes the compile user an ordinary package-local
symbol for the name of embedded fields of builtin type.

This is incompatible with the fix delivered for issue 2687
(revision 3c060add43fb) but fixes it in a different way, because
the explicit symbol on the field makes the typechecker able to
find it in lookdot.

Fixes #3552.

R=lvd, rsc, daniel.morsing
CC=golang-dev
https://golang.org/cl/6866047

The typechecking code was doing an extra, unnecessary
indirection.

Fixes #4458.

R=golang-dev, daniel.morsing, rsc
CC=golang-dev
https://golang.org/cl/6998051

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