I got a complaint that cgo output triggers warnings with
-Wdeclaration-after-statement. I don't think it's worth testing for
this--C has permitted declarations after statements since C99--but it is
easy enough to fix. It may break again; so it goes.
This CL also fixes errno handling to avoid getting confused if the tsan
functions happen to change the global errno variable.
Change-Id: I0ec7c63a6be5653ef44799d134c8d27cb5efa441
Reviewed-on: https://go-review.googlesource.com/22686
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
https://golang.org/cl/10173 intrduced msigsave, ensureSigM and
_SigUnblock but didn't enable the new signal save/restore mechanism for
SIG{HUP,INT,QUIT,ABRT,TERM} on DragonFly BSD, FreeBSD and OpenBSD.
At present, it looks like they have the implementation. This change
enables the new mechanism on DragonFly BSD, FreeBSD and OpenBSD the same
as Darwin, NetBSD.
Change-Id: Ifb4b4743b3b4f50bfcdc7cf1fe1b59c377fa2a41
Reviewed-on: https://go-review.googlesource.com/18657
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Add a C.CBytes function to copy a Go byte slice into C memory. This
returns an unsafe.Pointer, since that is what needs to be passed to
C.free, and the data is often opaque bytes anyway.
Fixes#14838
Change-Id: Ic7bc29637eb6f1f5ee409b3898c702a59833a85a
Reviewed-on: https://go-review.googlesource.com/20762
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Latest version of gcc (tdm-1) 5.1.0 refuses to compile our code
on windows/386 (see issue for details). Rewrite the code.
Fixes#14328
Change-Id: I70f4f063282bd2958cd2175f3974369dd49dd8dc
Reviewed-on: https://go-review.googlesource.com/20008
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
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>
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>
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>
[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>
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>
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>
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>
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>
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>
When using gccgo it's OK if a pointer passed to C remains on the stack.
Gccgo does not have the clear distinction between C and Go stacks.
Change-Id: I3af9dd6fe078214ab16d9d8dad2d206608d7891d
Reviewed-on: https://go-review.googlesource.com/16774
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
This implements part of the proposal in issue 12416 by adding dynamic
checks for passing pointers from Go to C. This code is intended to be
on at all times. It does not try to catch every case. It does not
implement checks on calling Go functions from C.
The new cgo checks may be disabled using GODEBUG=cgocheck=0.
Update #12416.
Change-Id: I48de130e7e2e83fb99a1e176b2c856be38a4d3c8
Reviewed-on: https://go-review.googlesource.com/16003
Reviewed-by: Russ Cox <rsc@golang.org>
This is, in effect, what the gc toolchain does. It fixes cases where Go
code refers to a C global variable; without this, if the global variable
was the only thing visible in the C code, the generated cgo file might
not get pulled in from the archive, leaving the Go variable
uninitialized.
This was reported against gccgo as https://gcc.gnu.org/PR68255 .
Change-Id: I3e769dd174f64050ebbff268fbbf5e6fab1e2a1b
Reviewed-on: https://go-review.googlesource.com/16775
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Replace the confusing game where a frame size of $-8 would suppress the
implicit setting up of a stack frame with a nice explicit flag.
The code to set up the function prologue is still a little confusing but better
than it was.
Change-Id: I1d49278ff42c6bc734ebfb079998b32bc53f8d9a
Reviewed-on: https://go-review.googlesource.com/15670
Reviewed-by: Minux Ma <minux@golang.org>
Fixes these warnings from go vet:
buildid_linux.go:25: no formatting directive in Fatalf call
callback.go:180: arg pc[i] for printf verb %p of wrong type: uintptr
env.go:34: possible misuse of unsafe.Pointer
issue7665.go:22: possible misuse of unsafe.Pointer
Change-Id: I83811b9c10c617139713a626b4a34ab05564d4fe
Reviewed-on: https://go-review.googlesource.com/15802
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Glibc uses some special signals for special thread operations. These
signals will be used in programs that use cgo and invoke certain glibc
functions, such as setgid. In order for this to work, these signals
need to not be masked by any thread. Before this change, they were
being masked by programs that used os/signal.Notify, because it
carefully masks all non-thread-specific signals in all threads so that a
dedicated thread will collect and report those signals (see ensureSigM
in signal1_unix.go).
This change adds the two glibc special signals to the set of signals
that are unmasked in each thread.
Fixes#12498.
Change-Id: I797d71a099a2169c186f024185d44a2e1972d4ad
Reviewed-on: https://go-review.googlesource.com/14297
Reviewed-by: David Crawshaw <crawshaw@golang.org>
It's because runtime links to ntdll, and ntdll exports a couple
incompatible libc functions. We must link to msvcrt first and
then try ntdll.
Fixes#12030.
Change-Id: I0105417bada108da55f5ae4482c2423ac7a92957
Reviewed-on: https://go-review.googlesource.com/14472
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
In order to fix issue #9401 the compiler was changed to add a padding
byte to any non-empty Go struct that ends in a zero-sized field. That
causes the Go version of such a C struct to have a different size than
the C struct, which can considerable confusion. Change cgo so that it
discards any such zero-sized fields, so that the Go and C structs are
the same size.
This is a change from previous releases, in that it used to be
possible to refer to a zero-sized trailing field (by taking its
address), and with this change it no longer is. That is unfortunate,
but something has to change. It seems better to visibly break
programs that do this rather than to silently break programs that rely
on the struct sizes being the same.
Update #9401.
Fixes#11925.
Change-Id: I3fba3f02f11265b3c41d68616f79dedb05b81225
Reviewed-on: https://go-review.googlesource.com/12864
Reviewed-by: Russ Cox <rsc@golang.org>
The one in misc/makerelease/makerelease.go is particularly bad and
probably warrants rotating our keys.
I didn't update old weekly notes, and reverted some changes involving
test code for now, since we're late in the Go 1.5 freeze. Otherwise,
the rest are all auto-generated changes, and all manually reviewed.
Change-Id: Ia2753576ab5d64826a167d259f48a2f50508792d
Reviewed-on: https://go-review.googlesource.com/12048
Reviewed-by: Rob Pike <r@golang.org>
Fix build error when CL=clang introduced by CL 10173.
Change-Id: I8edf210787a9803280c0779ff710c7e634a820d6
Reviewed-on: https://go-review.googlesource.com/10341
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Ian proposed an improved way of handling signals masks in Go, motivated
by a problem where the Android java runtime expects certain signals to
be blocked for all JVM threads. Discussion here
https://groups.google.com/forum/#!topic/golang-dev/_TSCkQHJt6g
Ian's text is used in the following:
A Go program always needs to have the synchronous signals enabled.
These are the signals for which _SigPanic is set in sigtable, namely
SIGSEGV, SIGBUS, SIGFPE.
A Go program that uses the os/signal package, and calls signal.Notify,
needs to have at least one thread which is not blocking that signal,
but it doesn't matter much which one.
Unix programs do not change signal mask across execve. They inherit
signal masks across fork. The shell uses this fact to some extent;
for example, the job control signals (SIGTTIN, SIGTTOU, SIGTSTP) are
blocked for commands run due to backquote quoting or $().
Our current position on signal masks was not thought out. We wandered
into step by step, e.g., http://golang.org/cl/7323067 .
This CL does the following:
Introduce a new platform hook, msigsave, that saves the signal mask of
the current thread to m.sigsave.
Call msigsave from needm and newm.
In minit grab set up the signal mask from m.sigsave and unblock the
essential synchronous signals, and SIGILL, SIGTRAP, SIGPROF, SIGSTKFLT
(for systems that have it).
In unminit, restore the signal mask from m.sigsave.
The first time that os/signal.Notify is called, start a new thread whose
only purpose is to update its signal mask to make sure signals for
signal.Notify are unblocked on at least one thread.
The effect on Go programs will be that if they are invoked with some
non-synchronous signals blocked, those signals will normally be
ignored. Previously, those signals would mostly be ignored. A change
in behaviour will occur for programs started with any of these signals
blocked, if they receive the signal: SIGHUP, SIGINT, SIGQUIT, SIGABRT,
SIGTERM. Previously those signals would always cause a crash (unless
using the os/signal package); with this change, they will be ignored
if the program is started with the signal blocked (and does not use
the os/signal package).
./all.bash completes successfully on linux/amd64.
OpenBSD is missing the implementation.
Change-Id: I188098ba7eb85eae4c14861269cc466f2aa40e8c
Reviewed-on: https://go-review.googlesource.com/10173
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This doesn't test much with gccgo, but at least it builds now, and the
test does, unsurprisingly, pass. A proper test would require adding
assembly files in GCC syntax for all platforms that gccgo supports,
which would be infeasible.
Also added copyright headers to the asm files.
Change-Id: Icea5af29d7d521a0681506ddb617a79705b76d33
Reviewed-on: https://go-review.googlesource.com/9417
Reviewed-by: Minux Ma <minux@golang.org>
This memory is untyped and can't be used anymore.
The next version of SWIG won't need it.
Change-Id: I592b287c5f5186975ee09a9b28d8efe3b57134e7
Reviewed-on: https://go-review.googlesource.com/8956
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Because there is no libgcc.
Change-Id: I3b3f80791a1db4c2b7318f81a115972cd2237f07
Signed-off-by: Shenghou Ma <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/8786
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Only documentation / comment changes. Update references to
point to golang.org permalinks or go.googlesource.com/go.
References in historical release notes under doc are left as is.
Change-Id: Icfc14e4998723e2c2d48f9877a91c5abef6794ea
Reviewed-on: https://go-review.googlesource.com/4060
Reviewed-by: Ian Lance Taylor <iant@golang.org>
On Darwin/ARM, because libSystem doesn't provide functions for
__sync_fetch_and_add, and only clang can inline that function,
skip the test when building with GCC.
Change-Id: Id5e9d8f9bbe1e6bcb2f381f0f66cf68aa95277c7
Reviewed-on: https://go-review.googlesource.com/2125
Reviewed-by: Ian Lance Taylor <iant@golang.org>
While we're here, rename TestIssue7234 to Test7234 for consistency
with other tests.
Fixes#9557.
Change-Id: I22b0a212b31e7b4f199f6a70deb73374beb80f84
Reviewed-on: https://go-review.googlesource.com/2654
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This test is doing pointer graph manipulation from C, and we
cannot support that with concurrent GC. The wbshadow mode
correctly diagnoses missing write barriers.
Disable the test in that mode for now. There is a bigger issue
behind it, namely SWIG, but for now we are focused on making
all.bash pass with wbshadow enabled.
Change-Id: I55891596d4c763e39b74082191d4a5fac7161642
Reviewed-on: https://go-review.googlesource.com/2346
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
Use typedmemmove, typedslicecopy, and adjust reflect.call
to execute the necessary write barriers.
Found with GODEBUG=wbshadow=2 mode.
Eventually that will run automatically, but right now
it still detects other missing write barriers.
Change-Id: Iec5b5b0c1be5589295e28e5228e37f1a92e07742
Reviewed-on: https://go-review.googlesource.com/2312
Reviewed-by: Keith Randall <khr@golang.org>
For Go 1.5, we can use go:linkname rather than assembly thunk for gc.
Gccgo already has support for //extern.
Change-Id: I5505aa247dd5b555112f7261ed2f192c81cf0bdf
Signed-off-by: Shenghou Ma <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/1888
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
issue9400_linux.go did not build on 386 because it used a constant
that was larger than a 32-bit int in a ... argument. Fix this by
casting the constant to uint64 (to match how the constant is being
used).
Change-Id: Ie8cb64c3910382a41c7852be7734a62f0b2d5a21
Reviewed-on: https://go-review.googlesource.com/2060
Reviewed-by: Ian Lance Taylor <iant@golang.org>
These signals are used by glibc to broadcast setuid/setgid to all
threads and to send pthread cancellations. Unlike other signals, the
Go runtime does not intercept these because they must invoke the libc
handlers (see issues #3871 and #6997). However, because 1) these
signals may be issued asynchronously by a thread running C code to
another thread running Go code and 2) glibc does not set SA_ONSTACK
for its handlers, glibc's signal handler may be run on a Go stack.
Signal frames range from 1.5K on amd64 to many kilobytes on ppc64, so
this may overflow the Go stack and corrupt heap (or other stack) data.
Fix this by ensuring that these signal handlers have the SA_ONSTACK
flag (but not otherwise taking over the handler).
This has been a problem since Go 1.1, but it's likely that people
haven't encountered it because it only affects setuid/setgid and
pthread_cancel.
Fixes#9600.
Change-Id: I6cf5f5c2d3aa48998d632f61f1ddc2778dcfd300
Reviewed-on: https://go-review.googlesource.com/1887
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Gccgo can only get a backtrace for the currently running thread, which
means that it can only get a backtrace for goroutines currently running
Go code. When a goroutine is running C code, gccgo has no way to stop
it and get the backtrace. This test is all about getting a backtrace
of goroutines running C code, so it can't work for gccgo.
Change-Id: I2dff4403841fb544da7396562ab1193875fc14c3
Reviewed-on: https://go-review.googlesource.com/1904
Reviewed-by: Minux Ma <minux@golang.org>
