PIE binaries can be built by the Go compiler in external link mode with
extldflags="-pie". These binaries support ASLR (address space layout
randomization) when executed on systems with appropriate kernel/dynamic
linker support.

This CL enables some cgo tests to run with -pie as a sanity check (in
addition to the other linker flag combinations they already test).

I have tested this functionality more thoroughly by building the full
compiler testsuite (test/...) and standard library tests with -pie
and executing them remotely on ChromeOS devices for all three linux
architectures (linux_amd64, linux_386, and linux_arm).

Change-Id: I3f644a72e94c3341f3360dfee58db5ec3a591e26
Reviewed-on: https://go-review.googlesource.com/6280Reviewed-by: Ian Lance Taylor <iant@golang.org>

This script is getting very close to complete, and is complex enough
that I'd like to get what's there so far reviewed. With it the builder
is left failing on eight packages. Two of those involve correcting
GOROOT which may need modifications to this script, the others are
either a unix sockets bug I have to hunt down or are caused by lldb
getting stuck on SIGSEGV, a TODO.

Change-Id: I5ff933800167b6764b51ad195da7dcda61d59ff8
Reviewed-on: https://go-review.googlesource.com/6404Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>

Have the implementations of each architecture declare the one-operand,
destination-writing instructions instead of splitting the information between
there and asm.

Change-Id: I44899435011a4a7a398ed03c0801e9f81cc8c905
Reviewed-on: https://go-review.googlesource.com/6490Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: I49cda99f81b754e25fad1483de373f7d07d64808
Reviewed-on: https://go-review.googlesource.com/6452Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>

Broke some tests that assume $GORACE is unset (because it never is).
Those tests are arguably wrong, but this is more robust.

Change-Id: Id56daa160c9e7e01f301c1386791e410bbd5deef
Reviewed-on: https://go-review.googlesource.com/6480Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This is a roll forward of 2adc3bd6. It occurred to me that we will
want this code on both darwin/arm and darwin/arm64. Removing _arm from
the file name conveniently avoids #10032.

Change-Id: I3a96a3e7020907d9307af8f696e26ad55b2060f0
Reviewed-on: https://go-review.googlesource.com/6460Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>

Run rsc.io/grind rev a26569f on C->Go conversions.

The new change in grind is the inlining of goto targets.
If code says 'goto x' and the block starting at label x is unreachable
except through that goto and the code can be moved to where
the goto is without changing the meaning of its variable names,
grind does that move. Simlarly, a goto to a plain return statement
turns into that return statement (even if there are other paths to
the return statement).

Combined, these remove many long-distance gotos, which in turn
makes it possible to reduce the scope of more variable declarations.
(Because gotos can't jump across declarations, the gotos were
keeping the declarations from moving.)

Checked bit-for-bit compatibility with toolstash + buildall.

Reduces compiler runtime in html/template by about 12%.

Change-Id: Id727c0bd7763a61aa22f3daa00aeb8fccbc057a3
Reviewed-on: https://go-review.googlesource.com/6472Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>

There's no point to having them in every GOOS_GOARCH directory,
since they are neither GOOS- nor GOARCH-specific.
(There used to be other headers that were.)

This makes building for additional toolchains easier:
no need to run make.bash at all.

Fixes #10049.

Change-Id: I710ecaafd7a5c8cad85ccd595ea9cb6058f553b3
Reviewed-on: https://go-review.googlesource.com/6471Reviewed-by: Rob Pike <r@golang.org>

Change-Id: I2cae17d3f0d208c7ed1089bc5cb8f81022fcd36e
Reviewed-on: https://go-review.googlesource.com/6470Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>

Replaced by Ctxt.ByteOrder, which uses the standard binary.ByteOrder type.

Change-Id: I06cec0674c153a9ad75ff937f7eb934891effd0b
Reviewed-on: https://go-review.googlesource.com/6450Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Rob Pike <r@golang.org>

This avoids needing every invoked tool to have an identical
computation of the build defaults as the go command does.
It makes sure the tools all know what the go command wants.

Change-Id: I484f15982bfb93c86cde8fc9df7f456505270b87
Reviewed-on: https://go-review.googlesource.com/6409Reviewed-by: Rob Pike <r@golang.org>

Change-Id: Ic74830608fe077b4e97e8ce8009017c1e273c672
Reviewed-on: https://go-review.googlesource.com/6408Reviewed-by: Rob Pike <r@golang.org>

Before this CL, if you are on a darwin/amd64 machine and
cross-compile 9g for a linux/ppc64 machine, when you copy
9g over to that kind of machine and run it, you'll find it thinks
the default object target is darwin/amd64. Not useful.
Make the default target linux/ppc64 in this case. More useful.

Change-Id: I62f2e9cb5f60b3077a922b31cd023a9cb7a6cfda
Reviewed-on: https://go-review.googlesource.com/6407Reviewed-by: Rob Pike <r@golang.org>

OpenBSD's sigprocmask system call passes the signal mask by value
rather than reference, so vars are unnecessary.  Additionally,
declaring "var sigset_all = ^sigset_none" means sigset_all won't be
initialized until runtime_init is called, but the first call to
newosproc happens before then.

I've witnessed Go processes on OpenBSD crash from receiving SIGWINCH
on the newly created OS thread before it finished initializing.

Change-Id: I16995e7e466d5e7e50bcaa7d9490173789a0b4cc
Reviewed-on: https://go-review.googlesource.com/6440Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Move type definitions from chan1.go to chan.go and select.go.
Remove underscores from names.
Make c.buf unsafe.Pointer instead of *uint8.

Change-Id: I75cf8385bdb9f79eb5a7f7ad319495abbacbe942
Reviewed-on: https://go-review.googlesource.com/4900Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>

Currently the test fails if run more than once:

$ go test -v -run=TestChildServeCleansUp -cpu=1,1 net/http/fcgi
=== RUN TestChildServeCleansUp
--- PASS: TestChildServeCleansUp (0.00s)
=== RUN TestChildServeCleansUp
fatal error: all goroutines are asleep - deadlock!

The problem is that the writer mutates test input data,
so it is wrong on the second execution.

Change-Id: I4ca54dd2926c6986b2908023ac65e5e65630ed26
Reviewed-on: https://go-review.googlesource.com/6383Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This fixes runtime's TestBreakpoint on ppc64:
the Breakpoint frame was not showing up in the trace.

It seems like f.frame should be either the frame size
including the saved LR (if any) or the frame size
not including the saved LR.

On ppc64, f.frame is the frame size not including the saved LR.

On arm, f.frame is the frame size not including the saved LR,
except when that's -4, f.frame is 0 instead.

The code here in the runtime expects that f.frame is the frame
size including the saved LR.

Since all three disagree and nothing else uses f.frame anymore,
stop using it here too. Use funcspdelta, which tells us the exact
difference between the FP and SP. If it's zero, LR has not been
saved yet, so the one saved for sigpanic should be recorded.

This fixes TestBreakpoint on both ppc64 and ppc64le.
I don't really understand how it ever worked there.

Change-Id: I2d2c580d5c0252cc8471e828980aeedcab76858d
Reviewed-on: https://go-review.googlesource.com/6430Reviewed-by: Minux Ma <minux@golang.org>

The conversion accidentally dropped the +4 here.

Change-Id: Ic6181a759565c261bc1b084317f693ae249fd036
Reviewed-on: https://go-review.googlesource.com/6451Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: Ie4d8bedb9408372dff64e9a7fd857e1be4ee59e1
Reviewed-on: https://go-review.googlesource.com/6401Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

- Fixed term in preceding section: submitted -> merged.
- Clear transitions between web sites.
- Clarify "types" of G Accounts.
- Less verbose "Configure Git" instructions. [l10n]
- Google uses the term "sign in".
- Mention .gitcookie file created.

Update "Register with Gerrit".
- Link directly to gerrit /login/ .

HTML
- Removed non-ascii "hidden characters".
- Encoded some & and >.

Change-Id: I0d99102def6b32e09b8e42fa40e20227ad5e7568
Reviewed-on: https://go-review.googlesource.com/5892Reviewed-by: Andrew Gerrand <adg@golang.org>

Change-Id: I9b38b3a384722cf000eab18b62f73f90bcb56c5c
Reviewed-on: https://go-review.googlesource.com/6070Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

encountering unknown markers.

Change-Id: Ica86013308d69da2f5b486119235ff693135b2f1
Reviewed-on: https://go-review.googlesource.com/6393Reviewed-by: David Symonds <dsymonds@golang.org>
Run-TryBot: David Symonds <dsymonds@golang.org>

Looks like c2go and gcc disagree about the exact meaning of the
usual arithmetic conversions, in a way that broke 9l's archreloc.
Fix it.

It's very hard for me to see why the original C code did not say
what c2go interpreted it to say, but apparently it did not.
This is why Go has explicit numerical conversions.

Change-Id: I75bd73afd1fa4ce9a53c887e1bd7d1e26ff43ae4
Reviewed-on: https://go-review.googlesource.com/6405Reviewed-by: Russ Cox <rsc@golang.org>

This CL will break any uses of 'go tool 5a' etc.
That is intentional.
Code that invokes an assembler directly should be updated to use go tool asm.

We plan to keep the old5a around for bit-for-bit verification during
the release testing phase, but we plan to remove those tools for the
actual release. Renaming the directory now makes sure that lingering
references to 'go tool 5a' will be caught, changed to use asm, and
tested during the release evaluation.

Change-Id: I98748a7ddb34cc7f1b151c2ef421d3656821f5c2
Reviewed-on: https://go-review.googlesource.com/6366Reviewed-by: Rob Pike <r@golang.org>

Tests sometimes failed with:

ok   mime/internal/quotedprintable      0.606s
ok   mime/multipart                     0.819s
--- FAIL: TestPacketConn (0.10s)
    packetconn_test.go:96: PacketConn.ReadFrom failed: WSARecvFrom udp 127.0.0.1:64156: i/o timeout
FAIL
FAIL    net     3.602s
ok      net/http        4.618s
ok      net/http/cgi    0.576s

Theory: 100 ms is too short. Small timer granularity on Wnidows, or an
allocation in the middle causing a GC sometimes?

In any case, increase it to 500 ms.

Change-Id: I48cc4d600eb168db9f85c0fd05335dd630254c3c
Reviewed-on: https://go-review.googlesource.com/4922Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

Update #8859
Update #10042

Change-Id: Idc7eadb447b73563ce9085e50c2042652442c2d9
Reviewed-on: https://go-review.googlesource.com/6412Reviewed-by: Minux Ma <minux@golang.org>

Change-Id: Ic44d7837aaec58601e5d9cad8da5b958a809f4a0
Reviewed-on: https://go-review.googlesource.com/6400Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Plan 9 provides a /dev/random device to return a
stream of random numbers. However, the method used
to generate random numbers on Plan 9 is slow and
reading from /dev/random may block.

We don't want our Go programs to be significantly
slowed down just to slightly improve the distribution
of hash values.

So, we do the same thing as NaCl and rely exclusively
on extendRandom to generate pseudo-random numbers.

Fixes #10028.

Change-Id: I7e11a9b109c22f23608eb09c406b7c3dba31f26a
Reviewed-on: https://go-review.googlesource.com/6386Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

In CL 6350, Brad fixed the following system calls
to use the program-wide workding directory:

- bind
- chdir
- create
- open
- remove
- stat
- umount
- wstat

However, Russ Cox pointed out that the mount
system call should be fixed as well.

Change-Id: I6139ed11ba449f18c46e95269f4d0e51be7cec48
Reviewed-on: https://go-review.googlesource.com/6385Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

If a method called by fmt triggers a panic, the output usually says
so. However, there is heretofore undocumented special treatment for
a panic caused by formatting a nil value with an Error or String
method: the output is simply "<nil>". Document that behavior.

Change-Id: Id0f79dd0b3487f9d1c74a0856727bba5cc342be4
Reviewed-on: https://go-review.googlesource.com/6410Reviewed-by: David Crawshaw <crawshaw@golang.org>

The go_darwin_arm_exec script now tells lldb to move the working
directory into <bundle>/src/os on startup.

Change-Id: I0ada4969e9ea374f08c84ab736aab2097ac73dd8
Reviewed-on: https://go-review.googlesource.com/6369Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>

issue #10017: TestGdbPython 'print mapvar' is reported to fail on ppc64.
issue #10002: TestGdbPython 'print mapvar' is reported to fail on arm hardfloat.

The testcase now uses plain line number in main.  Unwinding issues are
unrelated to the GDB map prettyprinter feature.

Remove arch-specific t.Skip()s from those two issues.

Fixes #10017
Fixes #10002

Change-Id: I9d50ffe2f3eb7bf65dd17c8c76a2677571de68ba
Reviewed-on: https://go-review.googlesource.com/6267Reviewed-by: Minux Ma <minux@golang.org>

Change-Id: I65b50d2501fe822bc9044a851ac0b3467feadd9f
Reviewed-on: https://go-review.googlesource.com/6330Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

These files were left behind for the C implementation of the assemblers.
They're no longer needed.

This is the last of the cmd/cc directory.

Change-Id: I9231b23c27fead5695000097aeb694824747677d
Reviewed-on: https://go-review.googlesource.com/6367Reviewed-by: Minux Ma <minux@golang.org>

Change-Id: Ic66243674ac1dbf829c7523005e33611cc89ac83
Reviewed-on: https://go-review.googlesource.com/6362Reviewed-by: Rob Pike <r@golang.org>

mv cmd/new5l cmd/5l and so on.

Minimal changes to cmd/dist and cmd/go to keep things building.
More can be deleted in followup CLs.

Change-Id: I1449eca7654ce2580d1f413a56dc4a75f3d4618b
Reviewed-on: https://go-review.googlesource.com/6361Reviewed-by: Rob Pike <r@golang.org>

Change-Id: I783df66d762b52ad3d74340ad5692790cd0ab544
Reviewed-on: https://go-review.googlesource.com/6360Reviewed-by: Rob Pike <r@golang.org>

Change-Id: Ia36fa5e617ceacbbca9f30f4e109d94e515b38ef
Reviewed-on: https://go-review.googlesource.com/6336Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>

Using rsc.io/c2go rev fc8cbfa's run.ld script.

Change-Id: I4d4d14fce96f8ce7a934bf8b9701b84fa9cf772d
Reviewed-on: https://go-review.googlesource.com/6335Reviewed-by: Rob Pike <r@golang.org>

Change-Id: I77ab2bed5884b0763147703fd976d462d036336d
Reviewed-on: https://go-review.googlesource.com/6334Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>