Use pkgimport == nil (or not) to distinguish between
parsing .go source files where "p" exponent specifier
is not allowed and parsing .a or .o export data where
it is.  Use that to control error when p-exponent is
seen.

Fixes #9036

Change-Id: I8924f09c91d4945ef3f20e80a6e544008a94a7e4
Reviewed-on: https://go-review.googlesource.com/10450Reviewed-by: Russ Cox <rsc@golang.org>

This is an automated follow-up to CL 10210.
It was generated with a combination of eg and gofmt -r.

No functional changes. Passes toolstash -cmp.

Change-Id: I35f5897948a270b472d8cf80612071b4b29e9a2b
Reviewed-on: https://go-review.googlesource.com/10253Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

TestGoroutineParallelism can deadlock if the GC runs during the
test. Currently it tries to prevent this by forcing a GC before the
test, but this is best effort and fails completely if GOGC is very low
for testing.

This change replaces this best-effort fix with simply setting GOGC to
off for the duration of the test.

Change-Id: I8229310833f241b149ebcd32845870c1cb14e9f8
Reviewed-on: https://go-review.googlesource.com/10454Reviewed-by: Russ Cox <rsc@golang.org>

Currently when the race detector is enabled, orderexpr always creates
a temporary for slice and append operations. This used to be necessary
because the race detector had a different code path for slice
assignment that required this temporary. Unfortunately, creating this
temporary inhibits the optimization that eliminates write barriers
when a slice is assigned only to change its length or cap. For most
code, this is bad for performance, and in go:nowritebarrier functions
in the runtime, this can mean the difference between compiling and not
compiling.

Now the race detector uses the regular slice assignment code, so
creating this temporary is no longer necessary.

Change-Id: I296042e1edc571b77c407f709c2ff9091c4aa795
Reviewed-on: https://go-review.googlesource.com/10456Reviewed-by: Russ Cox <rsc@golang.org>

Most runtime tests that invoke the compiler to build a sub-test binary
do so with a special environment constructed by testEnv that strips
out environment variables that should apply to the test but not to the
build.

Fix TestGdbPython to use this test environment when invoking go build,
like other tests do.

Change-Id: Iafdf89d4765c587cbebc427a5d61cb8a7e71b326
Reviewed-on: https://go-review.googlesource.com/10455Reviewed-by: Russ Cox <rsc@golang.org>

A decimal represented 0.0 with a 0-length mantissa and undefined
exponent, but the formatting code assumes a valid zero exponent
if the float value is 0.0. The code worked because we allocate a
new decimal value each time and because there's no rounding that
lead to 0.0.

Change-Id: Ifd771d7709de83b87fdbf141786286b4c3e13d4f
Reviewed-on: https://go-review.googlesource.com/10448Reviewed-by: Alan Donovan <adonovan@google.com>

Change-Id: I3a6df0a76d57db7cb6910f4179a6ce380f219a37
Reviewed-on: https://go-review.googlesource.com/10442Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This is dead code that was missed
during the 'go tool compile' migration.

Change-Id: Ice2af8a9ef72f8fd5f82225ee261854d93b659f1
Reviewed-on: https://go-review.googlesource.com/10430Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

It shrinks Prog type from 448 bytes down to 376 bytes on amd64.

It also makes sense, because I don't know of any modern architecture
that have instructions which can write to two destinations, none of
which is a register (even x86 doesn't have such instructions).

Change-Id: I3061f1c9ac93d79ee2b92ecb9049641d0e0f6300
Reviewed-on: https://go-review.googlesource.com/10330Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Russ Cox <rsc@golang.org>

This speeds up sharded builds notably, by 1 second * the number of
tests.

Change-Id: Ib0295c31e4974f3003f72cb16c48949812b6f22b
Reviewed-on: https://go-review.googlesource.com/10460Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: Ibace718452b6dc029c5af5240117f5fc794c38cf
Reviewed-on: https://go-review.googlesource.com/10388Reviewed-by: Alan Donovan <adonovan@google.com>

- factor out handling of sign
- rename bstring, pstring to fmtB, fmtP consistent with fmtE, fmtF
- move all float-to-string conversion functions into ftoa.go
- no functional changes

Change-Id: I5970ecb874dc9c387630b59147d90bda16a5d8e6
Reviewed-on: https://go-review.googlesource.com/10387Reviewed-by: Alan Donovan <adonovan@google.com>

Change-Id: I590ac9e976d4044d1f4f280137ea9b38851a9fc2
Reviewed-on: https://go-review.googlesource.com/10424Reviewed-by: Alan Donovan <adonovan@google.com>

Fixes #10956

Change-Id: If8517094f04250c4f722e1e899a237eb6e170eb9
Reviewed-on: https://go-review.googlesource.com/10421
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>

Added a lineno parameter to treecopy and listtreecopy
(ignored if = 0).  When nodes are copied the copy is
assigned the non-zero lineno (normally this would be
the destination).

Fixes #8183

Change-Id: Iffb767a745093fb89aa08bf8a7692c2f0122be98
Reviewed-on: https://go-review.googlesource.com/10334Reviewed-by: Russ Cox <rsc@golang.org>

Change-Id: I48b5f10d703dba48ec8e67c58d4276befafb5524
Reviewed-on: https://go-review.googlesource.com/10420Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

We already read the address of a gcmask/gcprog out of the type data, but I
didn't know how many bytes to read. But it turns out that it's easy to
calculate, so change to do that. This means that we no longer depend on the
local symbols being present, allowing me to strip the shared libraries for
distribution and make them a lot smaller.

As a bonus, this makes LSym another 24 bytes smaller, down to 296 bytes now.

Change-Id: I379d359e28d63afae6753efd23efdf1fbb716992
Reviewed-on: https://go-review.googlesource.com/10377Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The motivation for this is the innocuous looking test case that is added. This
creates a stack exe -> libdep2.so -> libdep.so -> libruntime.so. The problem
comes from the fact that a function from libdep.so gets inlined all the way
into exe. This (unsurprisingly) means that the object file for exe references
symbols from libdep.so, which means that -ldep needs to be passed when linking
exe and it isn't. The fix is simply to pass it -- there is no harm in passing
it when it's not needed.

The thing is, it's not clear at all in the current code to see how the linker
can know that libdep2 is linked against libdep. It could look through the
DT_NEEDED entries in libdep2 and try to guess which are Go libraries, but it
feels better to be explicit. So this adds another SHT_NOTE section that lists
the shared libraries a shared library was linked against, and makes sure the
complete set of depended upon shared libraries is passed to the external
linker.

Change-Id: I79aa6f98b4db4721d657a7eb7b7f062269bf49e2
Reviewed-on: https://go-review.googlesource.com/10376Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #10959.
Fixes #10960.

Change-Id: I9a81a0e2b8275338d0d1c3f7f7265e0fd91f3de2
Reviewed-on: https://go-review.googlesource.com/10402
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Symonds <dsymonds@golang.org>

This makes for a more stable API for tools (including cmd/link itself) to
extract the abi hash from a shared library and makes it possible at all for a
library that has had the local symbol table removed.

The existing note-writing code only supports writing notes into the very start
of the object file so they are easy to find in core dumps. This doesn't apply
to the "go" notes and means that all notes have to fit into a fixed size
budget. That's annoying now we have more notes (and the next CL will add
another one) so this does a little bit of work to make adding notes that do not
have to go at the start of the file easier and moves the writing of the package
list note over to that mechanism, which lets me revert a hack that increased
the size budget mentioned above for -buildmode=shared builds.

Change-Id: I6077a68d395c8a2bc43dec8506e73c71ef77d9b9
Reviewed-on: https://go-review.googlesource.com/10375Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I8694ee5e5642c31815ae63cd414a3b1fcd9c95b0
Reviewed-on: https://go-review.googlesource.com/10411Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The LSym.Section and Section.Elfsect fields were defined as interface{} but
always had the same concrete type (*Section and *ElfShdr respectively) so just
define them with that type. Reduces size of LSym from 328 to 320 bytes and
reduces best-of-10 maxresident size from 246028k to 238036k when linking
libstd.so.

Change-Id: Ie7112c53e4c2c7ce5fe233b81372aa5633f572e8
Reviewed-on: https://go-review.googlesource.com/10410Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

This allows objdump to disassemble gcc generated binaries on OS X 10.6.

Change-Id: I1a5bfbf7c252e78215ef1f122520689d5ce6ddca
Reviewed-on: https://go-review.googlesource.com/10383Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #10957

Change-Id: I75fe25133dfcebd1682a8058b1c354ec894cc997
Reviewed-on: https://go-review.googlesource.com/10384
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

At some point this code should probably move to cmd/link/internal/ld,
but at least for now just handle c-archive like c-shared.

Change-Id: Ic17656529cb0fe189a37f15e670350ab13bb5276
Reviewed-on: https://go-review.googlesource.com/10385Reviewed-by: Andrew Gerrand <adg@golang.org>

- no "visible" change to spec but for updated date
- retired several outdated TODO items
- filed non-urgent issues 10953, 10954, 10955 for current TODOs

Change-Id: If87ad0fb546c6955a6d4b5801e06e5c7d5695ea2
Reviewed-on: https://go-review.googlesource.com/10382Reviewed-by: Ian Lance Taylor <iant@golang.org>

Add the AddressParser type to allow decoding any charset in
mail addresses.

Fixes #7079

Change-Id: Ic34efb3e3d804a4e17149a6c38cfd73f5f275ab7
Reviewed-on: https://go-review.googlesource.com/10392Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The new lower-level barriers work fine and don't need special handling,
because they appear to the race detector as (visible) ordinary assignments.

Change-Id: I7477d73a3deecbebf68716580678c595cc4151e3
Reviewed-on: https://go-review.googlesource.com/10316Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

It can be useful when debugging to be able to see what the external
linker is doing even when it succeeds.  In particular this permits
passing -v to the external linker to see precisely what it is doing.

Change-Id: Ifed441912d97bbebea20303fdb899e140b380215
Reviewed-on: https://go-review.googlesource.com/10363Reviewed-by: Minux Ma <minux@golang.org>

They will be compiled and added to the archive, just as though the
package used cgo.  In effect all SWIG packages now use cgo anyhow.

Change-Id: I5d5a28ed0ec4295f24036b2834218bc980f080d0
Reviewed-on: https://go-review.googlesource.com/10146Reviewed-by: Minux Ma <minux@golang.org>

Fixes #10806

Change-Id: I1be1f28ad60c913105d8417c42ec1b262f101f72
Reviewed-on: https://go-review.googlesource.com/10391Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Updates #10806

Change-Id: I734d6db026cc7c2e3099a76dc8db8e42b2b90aa7
Reviewed-on: https://go-review.googlesource.com/10390Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Implement the changes from CL 10173 on OpenBSD.

Change-Id: I2db1cd8141fd392a34753a1b8113e2e0401173b9
Reviewed-on: https://go-review.googlesource.com/10342
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

As mentioned in
http://gitweb.dragonflybsd.org/dragonfly.git/commit/727ccde8cce813911d885b7f6ed749dcea68a886,
DragonFly BSD is dropping support for IPv6 IPv4-mapped address.
Unfortunately, on some released versions we see the kernels pretend to
support the feature but actually not (unless tweaking some kernel states
via sysctl.)

To avoid unpredictable behavior, the net package assumes that all
DragonFly BSD kernels don't support IPv6 IPv4-mapped address.

Fixes #10764.

Change-Id: Ic7af3651e0372ec03774432fbb6b2eb0c455e994
Reviewed-on: https://go-review.googlesource.com/10071Reviewed-by: Ian Lance Taylor <iant@golang.org>

Updates #10845.

Change-Id: I4cec670c7db88c50a6e5619e611744e161d73b3c
Reviewed-on: https://go-review.googlesource.com/10131Reviewed-by: Ian Lance Taylor <iant@golang.org>

Float.Format supports the 'b' and 'p' format, both of which print
a binary ('p') exponent. The 'b' format always printed a sign ('+'
or '-') for the exponent; the 'p' format only printed a negative
sign for the exponent. This change makes the two consistent. It
also makes the 'p' format easier to read if the exponent is >= 0.

Also:
- Comments added elsewhere.

Change-Id: Ifd2e01bdafb3043345972ca22a90248d055bd29b
Reviewed-on: https://go-review.googlesource.com/10359Reviewed-by: Alan Donovan <adonovan@google.com>

Fix build error when CL=clang introduced by CL 10173.

Change-Id: I8edf210787a9803280c0779ff710c7e634a820d6
Reviewed-on: https://go-review.googlesource.com/10341Reviewed-by: Ian Lance Taylor <iant@golang.org>

Package-external tests must use the vendored math/big package, not
the original one, otherwise tests may fail if there are discrepancies
in the implementation.

Change-Id: Ic5f0489aa6420ffea1f488633453f871ce1f0f66
Reviewed-on: https://go-review.googlesource.com/10380Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I6ae3534defdae9367e1b856dbb8e846c3263a758
Reviewed-on: https://go-review.googlesource.com/10358Reviewed-by: Alan Donovan <adonovan@google.com>

This resolves the compiler part of issue #10321.

Change-Id: I44b9909f992b37dd34b1c5292decd12de3d3a65e
Reviewed-on: https://go-review.googlesource.com/10355Reviewed-by: Alan Donovan <adonovan@google.com>