Fixes #8517.

LGTM=dvyukov, alex.brainman
R=golang-codereviews, dvyukov, alex.brainman
CC=golang-codereviews
https://golang.org/cl/145890044

Update #8690

If liblink determines that the host doesn't support TLS it replaces the MRC call with a BL runtime.tls_read_fallback. The problem is save_g doesn't expect anyone to make any BL calls and hasn't setup its own link register properly so when runtime.tls_read_fallback returns the LR points to save_g, not save_g's caller so the RET at the end of the function turns into an infinite loop.

This fix is only a proof of concept, I think the real fix should go into liblink as its MRC substitution is not as transparent as expected.

LGTM=rsc
R=rsc, minux
CC=golang-codereviews
https://golang.org/cl/143050043

Fixes #8008.

LGTM=adg
R=golang-codereviews, nightlyone, adg
CC=golang-codereviews
https://golang.org/cl/138630045

We can't assume all those addresses are unmapped.
But at least one should be.

What we're really testing is that the program doesn't crash.

Fixes #8542.

LGTM=iant
R=golang-codereviews, iant, minux
CC=golang-codereviews
https://golang.org/cl/144120043

We mark DBG_PRINTEXCEPTION_C messages in VEH handler
as handled, thus preventing debugger from seeing them.
I don't see reason for doing that. The comment warns
of crashes, but I added test and don't see any crashes.

This is also simplify VEH handler before making
changes to fix issue 8006.

Update #8006

LGTM=rsc
R=golang-codereviews, rsc
CC=golang-codereviews
https://golang.org/cl/146800043

Fixes #7859.

LGTM=r
R=adonovan, r
CC=golang-codereviews
https://golang.org/cl/136710043

It fixes the TestRemoveAllRace test introduced
in CL 145860043.

LGTM=bradfitz
R=rsc, bradfitz
CC=golang-codereviews
https://golang.org/cl/147820044

This is to simplify VEH handler before making
changes to fix issue 8006.

Update #8006

LGTM=adg, rsc
R=golang-codereviews, adg, rsc
CC=golang-codereviews
https://golang.org/cl/138630043

Same fix as for SysUnused.
Fixes #8038.

LGTM=iant, alex.brainman
R=golang-codereviews, iant, alex.brainman
CC=golang-codereviews
https://golang.org/cl/147820043

The current Windows build failure happens because by
default runtime frames are excluded from stack traces.
Apparently the Windows breakpoint path dies with an
ordinary panic, while the Unix path dies with a throw.
Breakpoint is a strange function and I don't mind that it's
a little different on the two operating systems.

The panic squelches runtime frames but the throw shows them,
because throw is considered something that shouldn't have
happened at all, so as much detail as possible is wanted.

The runtime exclusion is meant to prevents printing too much noise
about internal runtime details. But exported functions are
not internal details, so show exported functions.
If the program dies because you called runtime.Breakpoint,
it's okay to see that frame.
This makes the Breakpoint test show Breakpoint in the
stack trace no matter how it is handled.

Should fix Windows build.
Tested on Unix by changing Breakpoint to fault instead
of doing a breakpoint.

TBR=brainman
CC=golang-codereviews
https://golang.org/cl/143300043

This fixes a couple of problems that occur when the linker
removes its temporary directory on Windows.  The linker only
creates and removes a temporary directory when doing external
linking.  Windows does not yet support external linking.
Therefore, these problems are only seen when using a
cross-compiler hosted on Windows.

In lib9, FindFirstFileW returns just the file name, not the
full path name.  Don't assume that we will find a slash.
Changed the code to work either way just in case.

In ld, Windows requires that files be closed before they are
removed, so close the output file before we might try to
remove it.

Fixes #8723.

LGTM=alex.brainman
R=golang-codereviews, alex.brainman
CC=golang-codereviews
https://golang.org/cl/141690043

It's just fundamentally incompatible with
Windows' pickiness about removing things
that are in use.

TBR=brainman
CC=golang-codereviews
https://golang.org/cl/142270043

LGTM=adg
R=adg
CC=golang-codereviews
https://golang.org/cl/143290043

Fixes #8738.

LGTM=adg
R=golang-codereviews, adg
CC=golang-codereviews
https://golang.org/cl/143260045

Fixes #8332.

LGTM=dvyukov
R=golang-codereviews, dvyukov
CC=golang-codereviews
https://golang.org/cl/138650044

Fixes #5397.

LGTM=adg
R=gri, adg
CC=golang-codereviews, rsc
https://golang.org/cl/144110044

Since CL 130990043, the GOTRACEBACK variable is
only used when the GODEBUG variable is set.
This change restores the original behavior.

LGTM=rsc
R=golang-codereviews, aram, gobot, r, rsc
CC=golang-codereviews
https://golang.org/cl/132520043

In Go 1.3 the runtime called panicstring to report errors like
divide by zero or memory faults. Now we call panic (gopanic)
with pre-allocated error values. That new path is missing the
checking that panicstring did, so add it there.

The only call to panicstring left is in cnew, which is problematic
because if it fails, probably the heap is corrupt. In that case,
calling panicstring creates a new errorCString (no allocation there),
but then panic tries to print it, invoking errorCString.Error, which
does a string concatenation (allocating), which then dies.
Replace that one panicstring with a throw: cnew is for allocating
runtime data structures and should never ask for an inappropriate
amount of memory.

With panicstring gone, delete newErrorCString, errorCString.
While we're here, delete newErrorString, not called by anyone.
(It can't be: that would be C code calling Go code that might
block or grow the stack.)

Found while debugging a malloc corruption.
This resulted in 'panic during panic' instead of a more useful message.

LGTM=khr
R=khr
CC=golang-codereviews
https://golang.org/cl/138290045

Fixes #7776.

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews, r
https://golang.org/cl/145860043

It fails about 25% of the time on OS X.
I don't know what it's trying to do.
Created issue 8764 to correct this, but for now disable.

LGTM=bradfitz, mikioh.mikioh
R=bradfitz, mikioh.mikioh
CC=golang-codereviews
https://golang.org/cl/144070044

Replace typeLock with copy-on-write map using atomic.Value.

benchmark                               old ns/op     new ns/op     delta
BenchmarkEndToEndPipe                   7722          7709          -0.17%
BenchmarkEndToEndPipe-2                 5114          4344          -15.06%
BenchmarkEndToEndPipe-4                 3192          2429          -23.90%
BenchmarkEndToEndPipe-8                 1833          1438          -21.55%
BenchmarkEndToEndPipe-16                1332          983           -26.20%
BenchmarkEndToEndPipe-32                1444          675           -53.25%
BenchmarkEndToEndByteBuffer             6474          6019          -7.03%
BenchmarkEndToEndByteBuffer-2           4280          2810          -34.35%
BenchmarkEndToEndByteBuffer-4           2264          1774          -21.64%
BenchmarkEndToEndByteBuffer-8           1275          979           -23.22%
BenchmarkEndToEndByteBuffer-16          1257          753           -40.10%
BenchmarkEndToEndByteBuffer-32          1342          644           -52.01%
BenchmarkEndToEndArrayByteBuffer        727725        671349        -7.75%
BenchmarkEndToEndArrayByteBuffer-2      394079        320473        -18.68%
BenchmarkEndToEndArrayByteBuffer-4      211785        178175        -15.87%
BenchmarkEndToEndArrayByteBuffer-8      141003        118857        -15.71%
BenchmarkEndToEndArrayByteBuffer-16     139249        86367         -37.98%
BenchmarkEndToEndArrayByteBuffer-32     144128        73454         -49.04%

LGTM=r
R=golang-codereviews, r
CC=golang-codereviews
https://golang.org/cl/147720043

Converting an integer to an interface{} allocates as of CL 130240043.

Fixes #8617.

LGTM=r
R=r
CC=golang-codereviews, khr
https://golang.org/cl/141700043

To clarify the dependency of NaCl platform.

LGTM=adg
R=golang-codereviews, adg
CC=golang-codereviews
https://golang.org/cl/143830044

It is left from the time when Value was implemented in assembly.
Now it is implemented in Go and race detector understands Go.
In particular the atomic operations must provide
all necessary synchronization.

LGTM=adg
R=golang-codereviews, adg
CC=golang-codereviews, khr, rsc
https://golang.org/cl/145880043

Example output:
gc26(1): 1+0+1038+0 us, 0 -> 1 MB, 19074 (88777-69703) objects, 5 gs, 184/0/0 sweeps, 0(0) handoff, 0(0) steal, 0/0/0 yields
It's useful to understand long scan times,
because goroutine traceback is slow.

LGTM=khr
R=golang-codereviews, khr
CC=golang-codereviews, rsc
https://golang.org/cl/136310044

benchmark                    old ns/op     new ns/op     delta
BenchmarkEncode              8641055       8646829       +0.07%

Fixes #7792.

LGTM=r
R=r
CC=dbathgate, golang-codereviews
https://golang.org/cl/147730043

Generated by a+c.

R=gobot
CC=golang-codereviews
https://golang.org/cl/142200043

We could probably free the G structures as well, but
for the allg list.  Leaving that for another day.

Fixes #8287

LGTM=rsc
R=golang-codereviews, dvyukov, khr, rsc
CC=golang-codereviews
https://golang.org/cl/145010043

The logic here is copied from mgc0.c's scanframe.
Mostly it is messages although the minsize code is new
(and I believe necessary).

I am hoping to get more information about the current
arm build failures (or, if it's the minsize thing, fix them).

TBR=khr
R=khr
CC=golang-codereviews
https://golang.org/cl/143180043

Should fix nacl/arm build.

TBR=minux
CC=golang-codereviews
https://golang.org/cl/145070043

CC=golang-codereviews
https://golang.org/cl/145050043

Fixes #8734.

LGTM=r, bradfitz, dvyukov
R=bradfitz, r, dvyukov
CC=golang-codereviews, iant, khr
https://golang.org/cl/143150043

CC=golang-codereviews
https://golang.org/cl/144050043

It will be 8K on windows because it needs 4K for the OS.
Similarly, plan9 will be 4K.

On linux/amd64, reduces size of 100,000 goroutines
from ~819MB to ~245MB.

Update #7514

LGTM=dvyukov
R=golang-codereviews, dvyukov, khr, aram
CC=golang-codereviews
https://golang.org/cl/145790043

For real this time.

LGTM=minux
R=golang-codereviews, minux
CC=golang-codereviews
https://golang.org/cl/141640043

CC=golang-codereviews
https://golang.org/cl/145800043

A Value provides an atomic load and store of a consistently typed value.
It's intended to be used with copy-on-write idiom (see the example).

Performance:
BenchmarkValueRead	50000000	        21.7 ns/op
BenchmarkValueRead-2	200000000	         8.63 ns/op
BenchmarkValueRead-4	300000000	         4.33 ns/op

TBR=rsc
R=golang-codereviews
CC=golang-codereviews
https://golang.org/cl/136710045

The liblink code to insert the FUNCDATA for a stack map
from the Go prototype was not correct for ARM
(different data structure layout).

Also, sync/atomic was missing some Go prototypes
for ARM-specific functions.

TBR=r
CC=golang-codereviews
https://golang.org/cl/143160045

semacquire might need to park the currently running G.  It can
only park if called from the G stack (because it has no way of
saving the M stack state).  So all calls to semacquire must come
from the G stack.

The three violators are GOMAXPROCS, ReadMemStats, and WriteHeapDump.
This change moves the semacquire call earlier, out of their C code
and into their Go code.

This seldom caused bugs because semacquire seldom actually had
to park the caller.  But it did happen intermittently.

Fixes #8749

LGTM=dvyukov
R=golang-codereviews, dvyukov, bradfitz
CC=golang-codereviews
https://golang.org/cl/144940043

CC=golang-codereviews
https://golang.org/cl/138530044