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Commit Graph

985 Commits

Author SHA1 Message Date
Ian Lance Taylor
eaf5235f98 misc/cgo/testsanitizers: don't run tsan tests on old clang
Fixes #14570.

Change-Id: Ief84a14585bfc209e38cdf15702c2f54ba759714
Reviewed-on: https://go-review.googlesource.com/20057
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
2016-03-01 00:56:14 +00:00
Ian Lance Taylor
f4717a902e misc/cgo/testsanitizers: test that tsan links
Update #14559.

Change-Id: I92603602e5d0a5fcae43f3084f234ff606447190
Reviewed-on: https://go-review.googlesource.com/20056
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-29 17:56:28 +00:00
Ian Lance Taylor
1df5183f4c misc/cgo/testsanitizers: report stderr if go run tsan*.go fails
Update #14559.

Change-Id: I8894f8e16902685f55a21d902199fbe0905f0558
Reviewed-on: https://go-review.googlesource.com/20050
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
2016-02-29 14:58:15 +00:00
Ian Lance Taylor
c8ef0df06c cmd/cgo: add hooks for thread sanitizer
When Go code is used with C code compiled with -fsanitize=thread, adds
thread sanitizer calls so that correctly synchronized Go code does not
cause spurious failure reports from the thread sanitizer.  This may
cause some false negatives, but for the thread sanitizer what is most
important is avoiding false positives.

Change-Id: If670e4a6f2874c7a2be2ff7db8728c6036340a52
Reviewed-on: https://go-review.googlesource.com/17421
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
2016-02-28 04:56:17 +00:00
kortschak
c86dbbe1b9 misc/cgo/fortran: clean up after successful helloworld.90 build
Change-Id: If03185a21e088c9b383a82c14d649805f00c8042
Reviewed-on: https://go-review.googlesource.com/20000
Reviewed-by: Minux Ma <minux@golang.org>
2016-02-28 04:30:41 +00:00
Ian Lance Taylor
71cc445cf9 cmd/cgo: recognize known C typedefs as types
Fixes #14483.

Change-Id: I0cddfe27fd8d00ba85659d0b618410e39ebf45cb
Reviewed-on: https://go-review.googlesource.com/19860
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-02-27 22:51:51 +00:00
Jeff R. Allen
ee177279a0 misc/cgo: fix wrong quote character
Single quotes to not expand variables inside of them.

Change-Id: I4a0622c0aebfc1c3f9d299f93f7a8253893b5858
Reviewed-on: https://go-review.googlesource.com/13661
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-02-26 19:39:51 +00:00
Derek Shockey
90fea9d09a misc/git: Fix non-literal period in pre-commit grep
Looks like this was intended to match a literal period to restrict
this to `.go` files, but in POSIX grep, the unescaped period matches
any character.

Change-Id: I20e00323baa9e9631792eff5035966297665bbee
Reviewed-on: https://go-review.googlesource.com/19880
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-02-26 19:06:38 +00:00
kortschak
a337e30620 cmd/dist: don't run fortran test if fortran compilation fails
Fixes #14498.

Change-Id: I4cfab3e45898466179cefbd31c6f7f796da82363
Reviewed-on: https://go-review.googlesource.com/19874
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-25 23:52:28 +00:00
kortschak
50c38d46e8 cmd/go, go/build: add support for Fortran
This change adds support for Fortran files (.f, .F, .for, .f90) to the
go tool, in a similar fashion to Objective-C/C++. Only gfortran is
supported out of the box so far but leaves other Fortran compiler
toolchains the ability to pass the correct link options via CGO_LDFLAGS.
A simple test (misc/cgo/fortran) has been added and plugged into the
general test infrastructure. This test is only enabled when the $FC
environment variable is defined (or if 'gfortran' was found in $PATH.)

Derived from CL 4114.

Change-Id: Ifc855091942f95c6e9b17d91c17ceb4eee376408
Reviewed-on: https://go-review.googlesource.com/19670
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-24 15:06:38 +00:00
Matthew Dempsky
1a94431a78 cmd/cgo: support multiple-value special form in VarDecl
Fixes #13930.

Change-Id: I124b7d31d1f2be05b7f23dafd1e52d9f3f02f3f0
Reviewed-on: https://go-review.googlesource.com/18623
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-02-18 20:12:20 +00:00
Russ Cox
558a213d55 build: mv cmd/vendor cmd/internal/unvendor
And update two imports in cmd/internal/objfile/disasm.go.
This makes GO15VENDOREXPERIMENT=0 ./make.bash work.
For Go 1.7 we will move it back.

Fixes #14236.

Change-Id: I429c9af4baff8496f83d113b1b03b90e309f4f48
Reviewed-on: https://go-review.googlesource.com/19384
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-09 20:36:08 +00:00
Ian Lance Taylor
e97096661e runtime: handle kindString in cgoCheckArg
It's awkward to get a string value in cgoCheckArg, but SWIG testing
revealed that it is possible.  The new handling of extra files in the
ptr.go test emulates what SWIG does with an exported function that
returns a string.

Change-Id: I453717f867b8a49499576c28550e7c93053a0cf8
Reviewed-on: https://go-review.googlesource.com/19020
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2016-01-27 22:50:37 +00:00
Russ Cox
e7ce1ba88c misc/cgo/test: disable sigaltstack test on darwin/386
It doesn't work there ("out of memory") and doesn't really matter.
Fixes build (now that we enable cgo on the darwin/386 builder.)

Change-Id: I1d91e51ecb88c54eae39ac9a76f2c0b4e45263b0
Reviewed-on: https://go-review.googlesource.com/19004
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-01-27 22:27:05 +00:00
Ian Lance Taylor
1aab7b9626 cmd/link: add -extar option to set ar program for c-archive
People who want to use -buildmode=c-archive in unusual cross-compilation
setups will need something like this.  It could also be done via (yet
another) environment variable but I use -extar by analogy with the
existing -extld.

Change-Id: I354cfabc4c470603affd13cd946997b3a24c0e6c
Reviewed-on: https://go-review.googlesource.com/18913
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-01-26 18:52:36 +00:00
Russ Cox
544f28a25e misc/cgo/test: fix test on darwin/386 with cgo enabled
Apparently the darwin/386 builder does not enable cgo.
This failure turned up running

	GOARCH=386 GOHOSTARCH=386 ./all.bash

on my Mac.

Change-Id: Ia2487c4fd85d4b0f9f564880f22d9fde379946c3
Reviewed-on: https://go-review.googlesource.com/18859
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-01-24 20:21:29 +00:00
Michael Hudson-Doyle
cd9fc3ebfb cmd/link: allow symbols from .a files to override those from .so files
https://golang.org/s/execmodes defines rules for how multiple codes of a go
package work when they end up in the address space of a single process, but
currently the linker blows up in this situation. Fix that by loading all .a
files before any .so files and ignoring duplicate symbols found when loading
shared libraries.

I know this is very very late for 1.6 but at least it should clearly not have
any effect when shared libraries are not in use.

Change-Id: I512ac912937e7502ff58eb5628b658ecce3c38e5
Reviewed-on: https://go-review.googlesource.com/18714
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
2016-01-20 19:53:53 +00:00
Joe Sylve
9efc46f1cb cmd/go: -buildmode=c-shared should work on darwin/386
* Enable c-shared buildmode on darwin/386
* dyld does not support text relocation on i386. Add -read_only_relocs suppress flag to linker

Fixes #13904

Change-Id: I9adbd20d3f36ce9bbccf1bffb746b391780d088f
Reviewed-on: https://go-review.googlesource.com/18500
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2016-01-13 18:24:38 +00:00
Russ Cox
fac8202c3f runtime: make NumGoroutine and Stack agree not to include system goroutines
[Repeat of CL 18343 with build fixes.]

Before, NumGoroutine counted system goroutines and Stack (usually) didn't show them,
which was inconsistent and confusing.

To resolve which way they should be consistent, it seems like

	package main
	import "runtime"
	func main() { println(runtime.NumGoroutine()) }

should print 1 regardless of internal runtime details. Make it so.

Fixes #11706.

Change-Id: If26749fec06aa0ff84311f7941b88d140552e81d
Reviewed-on: https://go-review.googlesource.com/18432
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Russ Cox <rsc@golang.org>
2016-01-13 01:46:01 +00:00
Ian Lance Taylor
21b4f234c7 runtime: for c-archive/c-shared, install signal handlers synchronously
The previous behaviour of installing the signal handlers in a separate
thread meant that Go initialization raced with non-Go initialization if
the non-Go initialization also wanted to install signal handlers.  Make
installing signal handlers synchronous so that the process-wide behavior
is predictable.

Update #9896.

Change-Id: Ice24299877ec46f8518b072a381932d273096a32
Reviewed-on: https://go-review.googlesource.com/18150
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-01-09 00:58:38 +00:00
Ian Lance Taylor
d91ec5bb40 cmd/cgo, runtime: recognize unsafe.Pointer(&s[0]) in cgo pointer checks
It's fairly common to call cgo functions with conversions to
unsafe.Pointer or other C types.  Apply the simpler checking of address
expressions when possible when the address expression occurs within a
type conversion.

Change-Id: I5187d4eb4d27a6542621c396cad9ee4b8647d1cd
Reviewed-on: https://go-review.googlesource.com/18391
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2016-01-08 03:56:30 +00:00
Ian Lance Taylor
2586af47f6 misc/cgo/testcarchive,testcshared: deflake tests
After a failure on the build dashboard I tested testcarchive test 2 and
found that it failed an average of 1 in 475 runs on my laptop.  With
this change it ran over 50,000 times without failing.  I bumped up the
other iteration limits to correspond.

Change-Id: I0155c68161a2c2a09ae25c91e9269f1e8702628d
Reviewed-on: https://go-review.googlesource.com/18309
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-01-07 01:32:29 +00:00
Ian Lance Taylor
a7cad52e04 runtime: preserve signal stack when calling Go on C thread
When calling a Go function on a C thread, if the C thread already has an
alternate signal stack, use that signal stack instead of installing a
new one.

Update #9896.

Change-Id: I62aa3a6a4a1dc4040fca050757299c8e6736987c
Reviewed-on: https://go-review.googlesource.com/18108
Reviewed-by: Russ Cox <rsc@golang.org>
2016-01-06 23:11:42 +00:00
Ian Lance Taylor
934e055f41 runtime: call msanwrite on object passed to runtime/cgo
Avoids an msan error when runtime/cgo is explicitly rebuilt with
-fsanitize=memory.

Fixes #13815.

Change-Id: I70308034011fb308b63585bcd40b0d1e62ec93ef
Reviewed-on: https://go-review.googlesource.com/18263
Reviewed-by: Russ Cox <rsc@golang.org>
2016-01-06 04:04:42 +00:00
Russ Cox
f2c36df9a2 misc/cgo/testcshared: print a little more about GOROOT on failure
For #13789.

Change-Id: I83973298a35afcf55627f0a72223098306a51f4b
Reviewed-on: https://go-review.googlesource.com/18233
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-01-05 14:19:24 +00:00
Ian Lance Taylor
a7d2b4d7ce runtime: disable a signal by restoring the original disposition
Fixes #13034.
Fixes #13042.
Update #9896.

Change-Id: I189f381090223dd07086848aac2d69d2c00d80c4
Reviewed-on: https://go-review.googlesource.com/18062
Reviewed-by: Russ Cox <rsc@golang.org>
2016-01-05 00:25:50 +00:00
Didier Spezia
dc5315c341 build: prevent the entire repo to be wiped out by cgo test scripts
Following the parallelization of some tests, a race condition can
occur in testcarchive, testshared and testcshared.

In some cases, it can result in the go env GOROOT command returning
corrupted data, which are then passed to a rm command.

Make the shell script more robust by not trusting the result of
the go env GOROOT command. It does not really fix the issue, but
at least prevent the entire repository to be deleted.

Updates #13789

Change-Id: Iaf04a7bd078ed3a82e724e35c4b86e6f756f2a2f
Reviewed-on: https://go-review.googlesource.com/18173
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2016-01-04 19:56:30 +00:00
Dan Peterson
0f3c229030 runtime: fix sigaltstack test Skipf format string
Change-Id: I9485ecbd9d546893e4f0db846b08d835fa7515d7
Reviewed-on: https://go-review.googlesource.com/18140
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-12-24 18:34:18 +00:00
Ian Lance Taylor
f7e51c1320 runtime: adjust gsignal stack to current signal stack
If non-Go code calls sigaltstack before a signal is received, use
sigaltstack to determine the current signal stack and set the gsignal
stack to use it.  This makes the Go runtime more robust in the face of
non-Go code.  We still can't handle a disabled signal stack or a signal
triggered with SA_ONSTACK clear, but we now give clear errors for those
cases.

Fixes #7227.
Update #9896.

Change-Id: Icb1607e01fd6461019b6d77d940e59b3aed4d258
Reviewed-on: https://go-review.googlesource.com/18102
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
2015-12-24 17:00:04 +00:00
Ian Lance Taylor
94ff47939a misc/cgo/testcarchive: skip test4 on darwin/{arm,arm64}
Fixes #13701.

Change-Id: I9825864d23aeba1971cf5f581e1e59ac4c9b87fd
Reviewed-on: https://go-review.googlesource.com/18090
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-12-22 16:16:02 +00:00
Ian Lance Taylor
fbdfa99246 runtime: for c-archive/c-shared, don't install unnecessary signal handlers
Only install signal handlers for synchronous signals that become
run-time panics.  Set the SA_ONSTACK flag for other signal handlers as
needed.

Fixes #13028.
Update #12465.
Update #13034.
Update #13042.

Change-Id: I28375e70641f60630e10f3c86e24b6e4f8a35cc9
Reviewed-on: https://go-review.googlesource.com/17903
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-12-18 22:27:38 +00:00
Shenghou Ma
a766d8e59c cmd/cgo: map C unsigned char back to _Ctype_uchar in error messages
Fixes #13635.

Change-Id: Icab4a45567f435f002a8f6c85db9538acf054a70
Reviewed-on: https://go-review.googlesource.com/17863
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-12-16 22:13:17 +00:00
Ian Lance Taylor
dcc821faf8 misc/cgo/gmp: change pi.go to use standard Go copyright header
This file is not part of the benchmark shootout, and we wrote it, so use
the usual copyright header, not a partial version of the shootout
license.

Fixes #13575.

Change-Id: Ib610e2ad82914b4ef096a2424cfffe3383db2d5b
Reviewed-on: https://go-review.googlesource.com/17715
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-12-11 13:29:46 +00:00
Russ Cox
05390a0793 misc/cgo/stdio: reenable tests
The build tags are necessary to keep "go build" in that directory
building only stdio.go, but we have to arrange for test/run.go to
treat them as satisfied.

Fixes #12625.

Change-Id: Iec0cb2fdc2c9b24a4e0530be25e940aa0cc9552e
Reviewed-on: https://go-review.googlesource.com/17454
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-12-05 21:24:30 +00:00
Russ Cox
b5e2ec8bbe misc/cgo/testcshared: use fd 100 instead of fd 10 for back-channel communication
There is a report that fd 10 is already in use when run on some OS X machines.
I don't see how, and I can't reproduce the problem on my own OS X machine,
but it's easy enough to fix.

Fixes #12161.

Change-Id: I73511bdd91258ecda181d60d2829add746d1198b
Reviewed-on: https://go-review.googlesource.com/17451
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-12-05 03:56:23 +00:00
Mohit Agarwal
70d558be8f misc/cgo/testsanitizers: check linux major/minor versions
Fix a typo in de5b386; using `$ver` to determine linux major/minor
versions would produce those for clang, use `$linuxver` instead.

Updates #12898.

Change-Id: I2c8e84ad02749fceaa958afd65e558bb0b08dddb
Reviewed-on: https://go-review.googlesource.com/17323
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-12-03 21:22:27 +00:00
Russ Cox
de5b386157 misc/cgo/testsanitizers: do not run with clang < 3.8 and Linux ≥ 4.1
These are simply incompatible. Clang fixed the bug but not in older versions.

Fixes #12898.

Change-Id: I74a3fd9134dadab6d0f074f8fd09e00d64558d7a
Reviewed-on: https://go-review.googlesource.com/17254
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-12-03 14:48:46 +00:00
Ian Lance Taylor
5a049aa4a6 cmd/cgo: error, not panic, if not enough arguments to function
Fixes #13423.

Change-Id: I41bb45790cca36c57a107796f0eca61287acb2a9
Reviewed-on: https://go-review.googlesource.com/17332
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-12-02 21:02:28 +00:00
Ian Lance Taylor
17360accab cmd/cgo: make the char * pointer in GoString const
This makes it more convenient for C code to use GoString with string
constants.  Since Go string values are immutable, the const qualifier is
appropriate in C.

Change-Id: I5fb3cdce2ce5079f1f0467a1544bb3a1eb27b811
Reviewed-on: https://go-review.googlesource.com/17067
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-11-29 16:55:40 +00:00
Matthew Dempsky
10cb39afc4 cmd/cgo: fix C.complexfloat and C.complexdouble
This also fixes an unintended behavior where C's "complex float" and
"complex double" types were interchangeable with Go's "complex64" and
"complex128" types.

Fixes #13402.

Change-Id: I73f96d9a4772088d495073783c6982e9634430e8
Reviewed-on: https://go-review.googlesource.com/17208
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-11-25 23:06:59 +00:00
Matthew Dempsky
de640d369d cmd/cgo: handle another Clang DWARF quirk
Without the fix:

    $ CC=clang-3.5 ./test.bash
    misc/cgo/errors/test.bash: BUG: expected error output to contain "C.ushort" but saw:
    # command-line-arguments
    ./issue13129.go:13: cannot use int(0) (type int) as type C.unsignedshort in assignment

Fixes #13129.

Change-Id: I2c019d2d000f5bfa3e33c477e533aff97031a84f
Reviewed-on: https://go-review.googlesource.com/17207
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-11-25 21:13:41 +00:00
Ian Lance Taylor
0417872809 cmd/cgo: ignore vars with no name or type if they have a AttrSpecification
Fixes #13344.

Change-Id: I33c6721fd33d144c85c87840ddf27ce15aa72328
Reviewed-on: https://go-review.googlesource.com/17151
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
2015-11-23 04:04:07 +00:00
Mohit Agarwal
54bd5a71d3 misc/cgo/testshared: add format specifier in Errorf calls
Found by cmd/vet

Change-Id: I29dd207ecd40fe703054e8ad4e81b3267ca89da2
Reviewed-on: https://go-review.googlesource.com/17160
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-11-21 10:19:16 +00:00
Ian Lance Taylor
5005a33987 cmd/cgo: put the real C function in the dynamic symbol table
In the past, cgo generated Go code and C code.  The C code was linked
into a shared library.  The Go code was built into an executable that
dynamically linked against that shared library.  C wrappers were
exported from the shared library, and the Go code called them.

It was all a long time ago, but in order to permit C code to call back
into Go, somebody implemented #pragma dynexport (https://golang.org/cl/661043)
to export a Go symbol into the dynamic symbol table.  Then that same
person added code to cgo to recognize //export comments
(https://golang.org/cl/853042).  The //export comments were implemented
by generating C code, to be compiled by GCC, that would refer to C code,
to be compiled by 6c, that would call the Go code.  The GCC code would
go into a shared library.  The code compiled by 6c would be in the Go
executable.  The GCC code needed to refer to the 6c code, so the 6c
function was marked with #pragma dynexport.  The important point here is
that #pragma dynexport was used to expose an internal detail of the
implementation of an exported function, because at the time it was
necessary.

Moving forward to today, cgo no longer generates a shared library and 6c
no longer exists.  It's still true that we have a function compiled by
GCC that refers to a wrapper function now written in Go.  In the normal
case today we are doing an external link, and we use a
//go:cgo_export_static function to make the Go wrapper function visible
to the C code under a known name.

The #pragma dynexport statement has become a //go:cgo_export_dynamic
comment on the Go code.  That comment only takes effect when doing
internal linking.  The comment tells the linker to put the symbol in the
dynamic symbol table.  That still makes sense for the now unusual case
of using internal linking with a shared library.

However, all the changes to this code have carefully preserved the
property that the //go:cgo_export_dynamic comment refers to an internal
detail of the implementation of an exported function.  That was
necessary a long time ago, but no longer makes sense.

This CL changes the code to put the actual C-callable function into the
dynamic symbol table.  I considered dropping the comment entirely, but
it turns out that there is even a test for this, so I preserved it.

Change-Id: I66a7958e366e5974363099bfaa6ba862ca327849
Reviewed-on: https://go-review.googlesource.com/17061
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
2015-11-20 00:19:07 +00:00
Ian Lance Taylor
0e2c635788 cmd/cgo, runtime: exported Go functions can't return a Go pointer
Update #12416.

Change-Id: Iccbcb12709d1ca9bea87274f44f93cfcebadb070
Reviewed-on: https://go-review.googlesource.com/17048
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-11-19 18:28:39 +00:00
Ian Lance Taylor
be1ef46775 runtime: add optional expensive check for invalid cgo pointer passing
If you set GODEBUG=cgocheck=2 the runtime package will use the write
barrier to detect cases where a Go program writes a Go pointer into
non-Go memory.  In conjunction with the existing cgo checks, and the
not-yet-implemented cgo check for exported functions, this should
reliably detect all cases (that do not import the unsafe package) in
which a Go pointer is incorrectly shared with C code.  This check is
optional because it turns on the write barrier at all times, which is
known to be expensive.

Update #12416.

Change-Id: I549d8b2956daa76eac853928e9280e615d6365f4
Reviewed-on: https://go-review.googlesource.com/16899
Reviewed-by: Russ Cox <rsc@golang.org>
2015-11-16 18:39:06 +00:00
Ian Lance Taylor
754f707f5f cmd/link, cmd/go, cmd/dist: use copy of libgcc.a for internal linking
Change the linker to use a copy of the C compiler support library,
libgcc.a, when doing internal linking.  This will be used to satisfy any
undefined symbols referenced by host objects.

Change the dist tool to copy the support library into a new directory
tree under GOROOT/pkg/libgcc.  This ensures that libgcc is available
even when building Go programs on a system that has no C compiler.  The
C compiler is required when building the Go installation in the first
place, but is not required thereafter.

Change the go tool to not link libgcc into cgo objects.

Correct the linker handling of a weak symbol in an ELF input object to
not always create a new symbol, but to use an existing symbol if there
is one; this is necessary on freebsd-amd64, where libgcc contains a weak
definition of compilerrt_abort_impl.

Fixes #9510.

Change-Id: I1ab28182263238d9bcaf6a42804e5da2a87d8778
Reviewed-on: https://go-review.googlesource.com/16741
Reviewed-by: Russ Cox <rsc@golang.org>
2015-11-14 18:56:17 +00:00
Brad Fitzpatrick
9f38d66857 misc/sortac: add tool to sort the AUTHORS and CONTRIBUTORS files
I keep losing this utility, used as part of other tools to auto-update
the AUTHORS and CONTRIBUTORS files.  Check it in to the repo so I
don't lose it, and so others can use it as well.

Updates #12042

Change-Id: Ib5886b85799087aaaddcec4c81169e2726322c05
Reviewed-on: https://go-review.googlesource.com/16824
Reviewed-by: Russ Cox <rsc@golang.org>
2015-11-12 17:07:09 +00:00
Ian Lance Taylor
880a689124 runtime: don't call msanread when running on the system stack
The runtime is not instrumented, but the calls to msanread in the
runtime can sometimes refer to the system stack.  An example is the call
to copy in stkbucket in mprof.go.  Depending on what C code has done,
the system stack may appear uninitialized to msan.

Change-Id: Ic21705b9ac504ae5cf7601a59189302f072e7db1
Reviewed-on: https://go-review.googlesource.com/16660
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-11-11 06:04:04 +00:00
Ian Lance Taylor
8f3f2ccac0 runtime: mark cgo callback results as written for msan
This is a fix for the -msan option when using cgo callbacks.  A cgo
callback works by writing out C code that puts a struct on the stack and
passes the address of that struct into Go.  The result parameters are
fields of the struct.  The Go code will write to the result parameters,
but the Go code thinks it is just writing into the Go stack, and
therefore won't call msanwrite.  This CL adds a call to msanwrite in the
cgo callback code so that the C knows that results were written.

Change-Id: I80438dbd4561502bdee97fad3f02893a06880ee1
Reviewed-on: https://go-review.googlesource.com/16611
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-11-11 05:58:19 +00:00