Change from using __go_set_closure to passing the closure
value in the static chain field. Uses new backend support for
setting the closure chain in a call from C via
__builtin_call_with_static_chain. Uses new support in libffi
for Go closures.
The old architecture specific support for reflect.MakeFunc is
removed, replaced by the libffi support.
All work done by Richard Henderson.
* go-gcc.cc (Gcc_backend::call_expression): Add chain_expr argument.
(Gcc_backend::static_chain_variable): New method.
From-SVN: r219776
The version from the master repository seems to be appropriate
for OpenSolaris but not for Solaris itself. Solaris 11.2
proper does not define TCP_KEEPIDLE or TCP_KEEPINTVL.
From-SVN: r219749
A recent libffi upgrade caused the reflect test to fail on
386. The problem case is a function that returns an empty
struct--a struct with no fields. The libffi library does not
recognize the existence of empty structs, presumably since
they can't happen in C. To work around this, the Go interface
to the libffi library changes an empty struct to void. This
normally works fine, but with the new libffi upgrade it fails
for a function that returns an empty struct. On 386 a
function that returns a struct is expected to pop the hidden
pointer when it returns. So when we convert an empty struct
to void, libffi is calling a function that pops the hidden
pointer but does not expect that to happen.
In the older version of libffi, this didn't matter, because
the libffi code for 386 used a frame pointer, so the fact that
the stack pointer was wonky when the function returned was
ignored as the stack pointer was immediately replaced by the
saved frame pointer. In the newer version of libffi, the 386
code is more efficient and does not use a frame pointer, and
therefore it matters whether libffi expects the function to
pop the hidden pointer or not.
This patch changes libgo to convert an empty to a struct with
a single field of type void. This seems to be enough to get
the test cases working again.
Of course the real fix would be to change libffi to handle
empty types, but as libffi uses size == 0 as a marker for an
uninitialized type, that would be a non-trivial change.
From-SVN: r219701
This upgrades all of libgo other than the runtime package to
the Go 1.4 release. In Go 1.4 much of the runtime was
rewritten into Go. Merging that code will take more time and
will not change the API, so I'm putting it off for now.
There are a few runtime changes anyhow, to accomodate other
packages that rely on minor modifications to the runtime
support.
The compiler changes slightly to add a one-bit flag to each
type descriptor kind that is stored directly in an interface,
which for gccgo is currently only pointer types. Another
one-bit flag (gcprog) is reserved because it is used by the gc
compiler, but gccgo does not currently use it.
There is another error check in the compiler since I ran
across it during testing.
gotools/:
* Makefile.am (go_cmd_go_files): Sort entries. Add generate.go.
* Makefile.in: Rebuild.
From-SVN: r219627
Don't look it up on PATH. This lets a go tool built as part
of a GCC build use the gccgo from the same build.
Also pass -c when assembling a .s file with gccgo.
From-SVN: r219358
Fix an unusual C to Go callback case. Newly created C threads
call into Go code, forcing the Go code to allocate new M and G
structures. While executing Go code, the stack is split. The
Go code then returns. Returning from a Go callback is treated
as entering a system call, so the G gcstack field is set to
point to the Go stack. In this case, though, we were called
from a newly created C thread, so we drop the extra M and G
structures. The C thread then exits.
Then a new C thread calls into Go code, reusing the previously
created M and G. The Go code requires a larger stack frame,
causing the old stack segment to be unmapped and a new stack
segment allocated. At this point the gcstack field is
pointing to the old stack segment.
Then a garbage collection occurs. The garbage collector sees
that the gcstack field is not nil, so it scans it as the first
stack segment. Unfortunately it points to memory that was
unmapped. So the program crashes.
The fix is simple: when handling extra G structures created
for callbacks from new C threads, clear the gcstack field.
From-SVN: r218699
Different compilers may have different release cadences or ABI
incompatibilities, so it does not make sense to use the same library
name for runtime libraries intended for different compilers.
This CL causes a libgo built by llgo to receive the name libgo-llgo.
Likewise, libgobegin is named libgobegin-llgo.
From-SVN: r217583
From Dominik Vogt.
* libgo/go/syscall/libcall_linux_s390.go: New file for s390 support.
* libgo/go/syscall/syscall_linux_s390.go: Ditto.
* libgo/go/syscall/libcall_linux_s390x.go: New file for s390x support.
* libgo/go/syscall/syscall_linux_s390x.go: Ditto.
* libgo/go/runtime/pprof/pprof.go (printStackRecord): Support s390 and
s390x.
* libgo/runtime/runtime.c (runtime_cputicks): Add support for s390 and
s390x
* libgo/mksysinfo.sh: Ditto.
(upcase_fields): New helper function
* libgo/go/debug/elf/file.go (applyRelocations): Implement relocations
on s390x.
(applyRelocationsS390x): Ditto.
(DWARF): Ditto.
* libgo/go/debug/elf/elf.go (R_390): New constants for S390 relocations.
(r390Strings): Ditto.
(String): Helper function for S390 relocations.
(GoString): Ditto.
* libgo/go/reflect/makefuncgo_s390.go: New file.
(S390MakeFuncStubGo): Implementation of s390 abi.
* libgo/go/reflect/makefuncgo_s390x.go: New file.
(S390xMakeFuncStubGo): Implementation of s390x abi.
* libgo/go/reflect/makefunc_s390.c: New file.
(makeFuncStub): s390 and s390x specific implementation of function.
* libgo/go/reflect/makefunc.go
(MakeFunc): Add support for s390 and s390x.
(makeMethodValue): Ditto.
(makeValueMethod): Ditto.
* libgo/Makefile.am (go_reflect_makefunc_s_file): Ditto.
(go_reflect_makefunc_file): Ditto.
* libgo/go/reflect/makefunc_dummy.c: Ditto.
* libgo/runtime/runtime.h (__go_makefunc_can_recover): Export prototype
for use in makefunc_s390.c.
(__go_makefunc_returning): Ditto.
* libgo/go/syscall/exec_linux.go (forkAndExecInChild): Fix order of the
arguments of the clone system call for s390[x].
* libgo/configure.ac (is_s390): New variable.
(is_s390x): Ditto
(LIBGO_IS_S390): Ditto.
(LIBGO_IS_S390X): Ditto.
(GOARCH): Support s390 and s390x.
* libgo/go/go/build/build.go (cgoEnabled): Ditto.
* libgo/go/go/build/syslist.go (goarchList): Ditto.
From-SVN: r217106
Backport https://codereview.appspot.com/155450044 from the
master Go library. Original description:
I came across this while debugging a GC problem in gccgo.
There is code in assignTo and cvtT2I that handles assignment
to all interface values. It allocates an empty interface even
if the real type is a non-empty interface. The fields are
then set for a non-empty interface, but the memory is recorded
as holding an empty interface. This means that the GC has
incorrect information.
This is extremely unlikely to fail, because the code in the GC
that handles empty interfaces looks like this:
obj = nil;
typ = eface->type;
if(typ != nil) {
if(!(typ->kind&KindDirectIface) || !(typ->kind&KindNoPointers))
obj = eface->data;
In the current runtime the condition is always true--if
KindDirectIface is set, then KindNoPointers is clear--and we
always want to set obj = eface->data. So the question is what
happens when we incorrectly store a non-empty interface value
in memory marked as an empty interface. In that case
eface->type will not be a *rtype as we expect, but will
instead be a pointer to an Itab. We are going to use this
pointer to look at a *rtype kind field. The *rtype struct
starts out like this:
type rtype struct {
size uintptr
hash uint32 // hash of type; avoids computation in hash tables
_ uint8 // unused/padding
align uint8 // alignment of variable with this type
fieldAlign uint8 // alignment of struct field with this type
kind uint8 // enumeration for C
An Itab always has at least two pointers, so on a
little-endian 64-bit system the kind field will be the high
byte of the second pointer. This will normally be zero, so
the test of typ->kind will succeed, which is what we want.
On a 32-bit system it might be possible to construct a failing
case by somehow getting the Itab for an interface with one
method to be immediately followed by a word that is all ones.
The effect would be that the test would sometimes fail and the
GC would not mark obj, leading to an invalid dangling
pointer. I have not tried to construct this test.
I noticed this in gccgo, where this error is much more likely
to cause trouble for a rather random reason: gccgo uses a
different layout of rtype, and in gccgo the kind field happens
to be the low byte of a pointer, not the high byte.
From-SVN: r216489
We want to create goroutines with a small stack, at least on
systems where split stacks are supported. We don't need to
create threads with a small stack.
From-SVN: r216353
PR go/60406
runtime: Check callers in can_recover if return address doesn't match.
Also use __builtin_extract_return_address and tighten up the
checks in FFI code.
Fixes PR 60406.
From-SVN: r216003
PR go/61877
refect: fix direct call of variadic method value
As reported in bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61877
gcc mainline has regressed in this. This CL adds the tests proposed
for the main Go repository:
https://codereview.appspot.com/151280043/https://codereview.appspot.com/152060043/
restores the code from the amd64/386 path that makes this work and
was lost when the Go 1.3 stdlib was merged and changes the FFI path
to call into the same helper code as the amd64/386 path.
I've only tested this on amd64 but I did test a version that was
patched to unconditionally take the FFI path.
From-SVN: r215859
This supports clang, which by default issues warnings about
unused command line arguments, a habit that interacts poorly
with configure scripts.
From-SVN: r215699
If the compiler inlines this function into kickoff, it may reuse
the TLS block address to load g. However, this is not necessarily
correct, as the call to g->entry in kickoff may cause the TLS
address to change. If the wrong value is loaded for g->status in
runtime_goexit, it may cause a runtime panic.
By marking the function as noinline we prevent the compiler from
reusing the TLS address.
From-SVN: r215484
The Go frontend passes closures through to functions using the
functions __go_set_closure and __go_get_closure. The
expectation is that there are no function calls between
set_closure and get_closure. However, it turns out that there
can be function calls if some of the function arguments
require type conversion to an interface type. Converting to
an interface type can allocate memory, and that can in turn
trigger a garbage collection, and that can in turn call pool
cleanup functions that may call __go_set_closure. So the
called function can see the wrong closure value, which is bad.
This patch fixes the problem in two different ways. First, we
move all type conversions in function arguments into temporary
variables so that they can not appear before the call to
__go_set_closure. (This required shifting the flatten phase
after the simplify_thunk phase, since the latter expects to
work with unconverted argument types.) Second, we fix the
memory allocation function to preserve the closure value
across any possible garbage collection.
A test case is the libgo database/sql check run with the
environment variable GOGC set to 1.
From-SVN: r213932
PR other/61895
runtime: Ignore small argv[0] file for backtrace.
Reportedly in some cases Docker starts processes with argv[0]
pointing to an empty file. That would cause libgo to pass
that empty file to libbacktrace, which would then fail to do
any backtraces. Everything should work fine if libbacktrace
falls back to /proc/self/exe.
This patch to libgo works around the problem by ignoring
argv[0] if it is a small file, or if stat fails. This is not
a perfect fix but it's an unusual problem.
From-SVN: r213513
