This is a port of https://golang.org/cl/18150 to the gccgo runtime.
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.
Reviewed-on: https://go-review.googlesource.com/19494
From-SVN: r233393
PR go/66904
cmd/go: fix "#cgo pkg-config:" comments with gccgo
Copy of https://golang.org/cl/18790 by Michael Hudson-Doyle.
The unique difficulty of #cgo pkg-config is that the linker flags are recorded
when the package is compiled but (obviously) must be used when the package is
linked into an executable -- so the flags need to be stored on disk somewhere.
As it happens cgo already writes out a _cgo_flags file: nothing uses it
currently, but this change adds it to the lib$pkg.a file when compiling a
package, reads it out when linking (and passes a version of the .a file with
_cgo_flags stripped out of it to the linker). It's all fairly ugly but it works
and I can't really think of any way of reducing the essential level of
ugliness.
Update golang/go#11739.
GCC PR 66904.
Reviewed-on: https://go-review.googlesource.com/19431
From-SVN: r233290
PR go/69511
runtime: change G gcstack_size field to size_t
Because its address is passed to __splitstack_find, which expects size_t*.
From Dominik Vogt in GCC PR 69511.
Reviewed-on: https://go-review.googlesource.com/19429
From-SVN: r233260
This fixes the long-standing bug in which the testing package misreports
the file/line of an error.
Reviewed-on: https://go-review.googlesource.com/19179
From-SVN: r233098
PR 68980
libgo/testsuite: portable ps usage in gotest
gotest is using "ps" to list descendant sleep
processes in its timeout handling, grepping
the command name.
We are currently using the "cmd" ps output
formatter, which is non-portable. We should
use "comm" which is part of the POSIX
standard, and outputs only the command name
and not the arguments.
Fixes https://gcc.gnu.org/PR68980
Reviewed-on: https://go-review.googlesource.com/18426
From-SVN: r232234
This change updates mksysinfo.sh so it correctly
includes the define NLA_HDRLEN in the syscall package.
Fixes golang/go/#13629
Reviewed-on: https://go-review.googlesource.com/17893
From-SVN: r231796
PR go/61303
runtime: don't overallocate in select code
If we've already allocated an fd_set, don't allocate another one.
Also, don't bother to read from rdwake if it wasn't returned in select.
Fixes https://gcc.gnu.org/PR61303.
Reviewed-on: https://go-review.googlesource.com/17243
From-SVN: r230922
PR go/68496
reflect: Allocate space for FFI functions returning a zero-sized type.
The libffi library does not understand zero-sized types. We represent
them as a struct with a single field of type void. If such a type is
returned from a function, libffi will copy 1 byte of data. Allocate
space for that byte, although we won't use it.
Fixes https://gcc.gnu.org/PR68496.
Reviewed-on: https://go-review.googlesource.com/17175
From-SVN: r230776
PR go/65785
net: don't run multicast listen test on nil interface in short mode
This is a backport of https://golang.org/cl/17154.
The gccgo bug report https://gcc.gnu.org/PR65785 points out that the
multicast listen tests will use the network even with -test.short.
Fix test by checking testing.Short with a nil interface.
Reviewed-on: https://go-review.googlesource.com/17158
From-SVN: r230695
When using the go command built from gccgo to build and
install a go tool, use the value from runtime GCCGOTOOLDIR as
the install directory.
This also fixes the output from 'go tool' when used with the
gccgo-built go command, to only include the go tools and not
other binaries found in the same directory.
Reviewed-on: https://go-review.googlesource.com/16516
From-SVN: r230677
Before Solaris 12 the sendfile function is found in -lsendfile, so look
for it there.
Solaris 12 adds some more types that use _in6_addr_t, that need to be
edited in mksysinfo.
Patch by Rainer Orth.
Reviewed-on: https://go-review.googlesource.com/16779
From-SVN: r230132
PR go/68255
cmd/go: always use --whole-archive for gccgo packages
This is a backport of https://golang.org/cl/16775.
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 .
Reviewed-on: https://go-review.googlesource.com/16778
From-SVN: r230120
PR go/66138
reflect, encoding/json, encoding/xml: fix unexported embedded structs
Bring in three changes from the master Go repository. These changes
will be in Go 1.6, but they are appropriate for gccgo now because they
resolve a long-standing discrepancy between how gc and gccgo handle the
PkgPath field for embedded unexported struct fields. The core issue is
described at https://golang.org/cl/7247. This has been reported against
gccgo as https://gcc.gnu.org/PR66138.
The three changes being brought over are:
https://golang.org/cl/14010
reflect: adjust access to unexported embedded structs
This CL changes reflect to allow access to exported fields and
methods in unexported embedded structs for gccgo and after gc
has been adjusted to disallow access to embedded unexported structs.
Adresses #12367, #7363, #11007, and #7247.
https://golang.org/cl/14011
encoding/json: check for exported fields in embedded structs
Addresses issue #12367.
https://golang.org/cl/14012
encoding/xml: check for exported fields in embedded structs
Addresses issue #12367.
Reviewed-on: https://go-review.googlesource.com/16723
From-SVN: r229907
Only build net/hook_cloexec.go on GNU/Linux and FreeBSD, because those
are the only systems with accept4.
Add syscall/libcall_bsd.go to define sendfile for *BSD and Solaris.
Revert tcpsockopt_solaris.go back to the earlier version, so that it
works on Solaris 10.
Always pass the address of a Pid_t value to TIOCGPGRP and TIOCSPGRP.
Include <unistd.h> in runtime/go-varargs.c.
Reviewed-on: https://go-review.googlesource.com/16719
From-SVN: r229880
I managed to add a new --goarch option to gotest without noticing that
the script already had one. Worse, they set different variables.
Remove the old option in favor of the new one.
Reviewed-on: https://go-review.googlesource.com/16613
From-SVN: r229734
When not using split stacks, libgo allocate large stacks for each
goroutine. On a 64-bit system, libgo allocates a maximum of 128G for
the Go heap, and allocates 4M for each stack. When the stacks are
allocated from the Go heap, the result is that a program can only create
32K goroutines, which is not enough for an active Go server. This patch
changes libgo to allocate the stacks using mmap directly, rather than
allocating them out of the Go heap. This change is only done for 64-bit
systems when not using split stacks. When using split stacks, the
stacks are allocated using mmap directly anyhow. On a 32-bit system,
there is no maximum size for the Go heap, or, rather, the maximum size
is the available address space anyhow.
Reviewed-on: https://go-review.googlesource.com/16531
From-SVN: r229636
Type descriptors picked up a zero field because the gc map
implementation used it. However, it's since been dropped by the gc
library. It was never used by gccgo. Drop it now in preparation for
upgrading to the Go 1.5 library.
Reviewed-on: https://go-review.googlesource.com/16486
From-SVN: r229546
Change the type descriptor hash and equal functions from C code pointers
to Go func values. This permits them to be set to a Go function
closure. This is in preparation for the Go 1.5, so that we can use a
closure for the hash/equal functions returned by the new reflect.ArrayOf
function.
Reviewed-on: https://go-review.googlesource.com/16485
From-SVN: r229541
This patch adds an easy way to write tests for expected multiline
output. For example we can test carets and underlines for
a particular diagnostic with:
/* { dg-begin-multiline-output "" }
typedef struct _GMutex GMutex;
^~~~~~~
{ dg-end-multiline-output "" } */
multiline.exp is used by prune.exp; hence we need to load it before
prune.exp via *load_gcc_lib* for the testsuites of the various
non-"gcc" support libraries (e.g. boehm-gc).
gcc/testsuite/ChangeLog:
* lib/multiline.exp: New file.
* lib/prune.exp: Load multiline.exp.
(prune_gcc_output): Call into multiline.exp to handle any
multiline output directives.
* lib/libgo.exp: Load multiline.exp before prune.exp, using
load_gcc_lib.
boehm-gc/ChangeLog:
* testsuite/lib/boehm-gc.exp: Load multiline.exp before
prune.exp, using load_gcc_lib.
libatomic/ChangeLog:
* testsuite/lib/libatomic.exp: Load multiline.exp before
prune.exp, using load_gcc_lib.
libgomp/ChangeLog:
* testsuite/lib/libgomp.exp: Load multiline.exp before prune.exp,
using load_gcc_lib.
libitm/ChangeLog:
* testsuite/lib/libitm.exp: Load multiline.exp before prune.exp,
using load_gcc_lib.
libvtv/ChangeLog:
* testsuite/lib/libvtv.exp: Load multiline.exp before prune.exp,
using load_gcc_lib.
From-SVN: r228655
PR go/67874
net, runtime: Call C library fcntl function rather than syscall.Syscall.
Not all systems define a fcntl syscall; some only have fcntl64.
Fixes GCC PR go/67874.
Reviewed-on: https://go-review.googlesource.com/15497
From-SVN: r228576
If the compiler supports split-stack but we are using a gold linker that
does not, as happens on PPC with current GCC but old gold, then we need
to compile the Go code with -fno-split-stack to avoid a linker error
avoid the inability to call from split-stack code to non-split-stack
code.
Reviewed-on: https://go-review.googlesource.com/14598
From-SVN: r227811
PPC has split-stack support in current GCC, but old version of gold will
reject attempts to link PPC split-stack and non-split-stack code
together. Test for that, and don't compile the C code with
-fsplit-stack if it doesn't work.
Reviewed-on: https://go-review.googlesource.com/14594
From-SVN: r227802
This avoids linker warnings when linking against glibc, as apparently
arm64 GNU/Linux does not support the ustat system call.
Also update to automake 1.11.6, as that is the new GCC standard.
Reviewed-on: https://go-review.googlesource.com/14567
From-SVN: r227777
From Rainer Orth.
Solaris 12 changes the stat_[amc]tim members of struct stat from
timestruc_t to timespec_t for XPG7 compatiblity, thus breaking the libgo
build. The following patch checks for this change and uses the common
stat_atim.go if appropriate.
Reviewed-on: https://go-review.googlesource.com/14495
From-SVN: r227665
If the timeout subshell has no child processes,
the "xargs | kill" will fail. Ensure there is
some input for kill before calling it.
Reviewed-on: https://go-review.googlesource.com/13295
From-SVN: r226719
The struct RawSockaddr contains a field Data which
should be uint8 on ppc64 and ppc64le, but is declared
as int8 in gccgo. This change adds a two new files
which contain the structure declaration for
RawSockaddr, one with the correct types for for ppc64
and ppc64le, and the other for non-ppc64 platforms.
Fixesgolang/go#11469
Reviewed-on: https://go-review.googlesource.com/11946
From-SVN: r226533
This change modifies the "gotest" shell script
to kill all processes, including "sleep", spawned
by the timeout subshell. This prevents the sleep
process from living beyond the gotest process.
BACKGROUND
The "gotest" shell script spawns "sleep" processes
in the background to kill off test cases that run
past their specified timeout. There are commands
included that appear to kill the sleep process,
but they only kill the parent shell, causing the
sleep process to reparent.
The orphaned sleep process can cause issues when
gotest is run under some build systems, such as
Ninja [0]. The particular issue with Ninja is the
method it uses to identify terminated processes:
it creates a pipe, passes the write end to the
child process, and waits for EOF. In the case of
libgo/gotest, the orphaned sleep process inherits
the pipe FD and keeps it open for 4 minutes by
default.
[0] https://github.com/martine/ninja
Reviewed-on: https://go-review.googlesource.com/12227
From-SVN: r226526
PR go/67101
runtime: Remove call to __builtin_frame_address.
__builtin_frame_address was only supposed to use nonzero arguments
for debugging purposes. Calling it with nonzero arguments can have
unpredictable results and uses are now marked unsafe when
-Wframe-address is enabled.
Reviewed-on: https://go-review.googlesource.com/13063
From-SVN: r226525
In a recent change to mksysinfo.sh, a space was missing on
some lines which caused the libgo build to hang on some
systems. This corrects that problem.
Fixesgolang/go#11924
Reviewed-on: https://go-review.googlesource.com/12835
From-SVN: r226366
During the gccgo build define constants from
some header files are processed by mksysinfo.sh and
added to syscall.go. In some cases the constants
are based on macros which are not processed
correctly by mksysinfo.sh. This adds the support
to generate the correct values for the TUN* constants
from linux/if_tun.h.
Fixesgolang/go#11707
Reviewed-on: https://go-review.googlesource.com/12491
From-SVN: r226196
As the removed comment states, if the package being compiled played
certain tricks with pointers that looked like integers, the compiler
might allocate space for new pointers unnecessarily. Since the type
information on the heap is now precise, this logic can be moved to the
runtime.
Reviewed-on: https://go-review.googlesource.com/11581
From-SVN: r225757
The syscall for Getdents in syscall/libcall_linux.go
called Entersyscall and Exitsyscall, causing the
runtime_sched counts for goroutines to be incorrect.
Inconsistent counts caused checkdead in runtime/proc.c
to panic.
Fixesgolang/go#11406
Reviewed-on: https://go-review.googlesource.com/11761
From-SVN: r225745
When libgo is not optimized the static function profilealloc
in malloc.goc shows up in the stack trace. Rename it to
runtime_profilealloc so that runtime/pprof.printStackRecord
ignores it.
From-SVN: r223006
These changes permit using the go tool from the upcoming Go
1.5 release with -buildmode=c-archive to build gccgo code into
an archive file that can be linked with a C program.
From-SVN: r222594
PR go/64683
runtime/pprof: Assume function with no name is in runtime.
GCC PR 65797 causes some of the runtime functions to be
compiled with no name in the debug info. This in turn causes
the runtime/pprof test to fail as reported in GCC PR 64683.
There are no good choices when a function has no name in the
debug info, but here we assume that if we see such a function
while reading the runtime functions, we assume that it is also
a runtime function.
From-SVN: r222200
PR go/65755
compiler, runtime, reflect: Use reflection string for type comparisons.
Change the runtime and reflect libraries to always use only
the type reflection string to determine whether two types are
equal. It previously used the PkgPath and Name values for a
type name, but that required a PkgPath that did not match the
gc compiler.
Change the compiler to use the same PkgPath value as the gc
compiler in all cases.
Change the compiler to put the receiver type in the reflection
string for a type defined inside a method.
From-SVN: r222194
PR go/63731
libgo: Build and install libnetgo.a
libnetgo.a provides the net
package built with the netgo
tag enabled. This provides the
netgo fallback solution for gccgo.
This lib must be explicitly linked
in using the -gccgoflags, so is
not included by default.
From-SVN: r221906
When linking complex packages that use both internal and external tests as well as many dependencies it is critical that the link order be external test package, internal test package, everything else.
This change is a back (forward?) port of the same change that canonical have been maintaining on their fork of the go tool for gccgo. Now that gccgo uses the go tool from upstream, this patch should be applied both to the gofrontend and golang/go repos.
From-SVN: r221800
PR go/65570
libgo/Makefile.am: add runtime/cgo to list of standard packages
The runtime/cgo package is treated specially by the go tool.
It needs to know that it is always available for gccgo.
From-SVN: r221673
PR go/65417
debug/elf: support reading debug info from 32-bit PPC objects
This is a backport of http://golang.org/7590 from the master
Go library.
From-SVN: r221644
PR go/65462
cmd: Fix dependencies for 'go get' with gccgo
Problem described in GCC BZ 65462.
Generate the list of the standard GO package names based on what was built into libgo in the libgo Makefile.
Change the var name from reqPkgSrc to reqStdPkgSrc to clarify it only affects standard GO packages.
Skip the attempted loading of a package only if it is a standard GO package and the flag is set indicating its source is not required to be available.
This requires a corresponding change to gotools to build and link in the new file containing the list of standard GO package names that was generated by the libgo Makefile.
gotools/:
PR go/65462
* Makefile.am (go_cmd_go_files): Add $(libgodir)/zstdpkglist.go.
* Makefile.in: Rebuild.
From-SVN: r221643
PR go/65349
runtime: Don't call malloc from __go_file_line callback.
When crashing, we call runtime_printcreatedby which calls
__go_file_line which used to call the Go malloc. If we are
crashing due to a signal due to heap corruption of some sort,
the GO malloc lock might already be held, leading to a crash
within a crash. Avoid that by assuming that the libbacktrace
strings will stick around, as we already do in go-callers.c.
From-SVN: r221291
From Rainer Orth.
The recent godump changes broke Solaris 11.1+ bootstrap in
libgo: before, gen-sysinfo.so had
type _zone_net_addr_t struct { zna_family uint16; zna_plen uint16; zna_addru struct { znau_addr6 _in6_addr; }; }
which was filtered out by mksysinfo.sh due to the use of
_in6_addr.
After the change, there's now
type _zone_net_addr_t struct { zna_family uint16; zna_plen uint16; zna_addru struct { znau_addr6 [16]byte; Godump_0_align [0]uint32; }; }
instead, not filtered, but added a second time by the
_zone_net_addr_t code in mksysinfo.sh, which leads to
redefinition warnings/errors.
Simply removing the old _zone_net_addr_t fragment fixes this
and restores bootstrap.
From-SVN: r220481
Add memprofilerate as a value recognized
in the GODEBUG env var. The value provided
is used as the new setting for
runtime.MemProfileRate, allowing the user
to adjust memory profiling.
From-SVN: r220470
PR go/64683
runtime/pprof: Let memory profiler test pass if value not collected.
Since gccgo's GC is not precise, the transient value may not
be collected. Let the regexp match that case as well.
From-SVN: r219900
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
This variable is unused apparently as a result of local changes.
gccgo accepts this variable declaration, but other frontends may not.
From-SVN: r212873
PR go/61620
runtime: Don't free tiny blocks in map deletion.
The memory allocator now has a special case for tiny blocks
(smaller than 16 bytes) and they can not be explicitly freed.
From-SVN: r212233
This introduces the "bench" build target, which can be used to run
all benchmarks.
It is also possible to run subsets of benchmarks with the
"package/check" build targets by setting GOBENCH to a matching regex.
From-SVN: r212212
PR go/52583
runtime: Stop backtrace at a few recognized functions.
On x86_64 Solaris the makecontext function does not properly
indicate that it is at the top of the stack. Attempting to
unwind the stack past a call to makecontext tends to crash.
This patch changes libgo to look for certain functions that
are always found at the top of the stack, and to stop
unwinding when it reaches one of those functions. There is
never anything interesting past these functions--that is,
there is never any code written by the user.
From-SVN: r211640
PR go/61498
runtime: Always set gcnext_sp to pointer-aligned address.
The gcnext_sp field is only used on systems that do not use
split stacks. It marks the bottom of the stack for the
garbage collector. This change makes sure that the stack
bottom is always aligned to a pointer value.
Previously the garbage collector would align all the addresses
that it scanned, but it now expects them to be aligned before
scanning.
From-SVN: r211639
This revision was committed January 7, 2014. The next
revision deleted runtime/mfinal.c. That will be done in a
subsequent merge.
This merge changes type descriptors to add a zero field,
pointing to a zero value for that type. This is implemented
as a common variable.
* go-gcc.cc (Gcc_backend::implicit_variable): Add is_common and
alignment parameters. Permit init parameter to be NULL.
From-SVN: r211249
This adds the --without-libatomic configure option, which is useful for building libgo
with a non-gcc compiler.
It disables libgo's dependency on libatomic. This
is useful for platforms where it is known that the libatomic runtime
functions are not required, or where the compiler automatically
provides an implementation of them.
From-SVN: r211065
LLVM's code generator does not currently support split stacks for vararg
functions, so we disable split stacks for the only function that uses this
feature under Clang. This appears to be OK as long as:
- this function only calls non-inlined, internal-linkage (hence no dynamic
loader) functions compiled with split stacks (i.e. go_vprintf), which can
allocate more stack space as required;
- this function itself does not occupy more than BACKOFF bytes of stack space
(see libgcc/config/i386/morestack.S).
These conditions are currently known to be satisfied by Clang on x86-32 and
x86-64. Note that signal handlers receive slightly less stack space than they
would normally do if they happen to be called while this function is being
run. If this turns out to be a problem we could consider increasing BACKOFF.
From-SVN: r211037
This includes the use of __complex and __builtin_ functions where
unprefixed entities would suffice, and the use of a union for
bit-casting between types.
From-SVN: r211036
PR go/60931
runtime: Fix garbage collector issue with non 4kB system page size
The go garbage collector tracks memory in terms of 4kB pages.
Most of the code checks getpagesize() at runtime and does the
right thing.
On a 64kB ppc64 box I see SEGVs in long running processes
which has been diagnosed as a bug in scavengelist.
scavengelist does a madvise(MADV_DONTNEED) without rounding
the arguments to the system page size. A strace of one of the
failures shows the problem:
madvise(0xc211030000, 4096, MADV_DONTNEED) = 0
The kernel rounds the length up to 64kB and we mark 60kB of
valid data as no longer needed.
Round start up to a system page and end down before calling
madvise.
From-SVN: r209777
A gccgo language extension allows a function to be declared multiple
times. Avoid the use of this extension by dedeplicating declarations
in mksyscall.awk.
From-SVN: r209508
Avoid the use of a gccgo language extension which allows unsafe.Sizeof
to accept a type by passing an expression of the relevant type.
From-SVN: r209503
This patch fixes a rare but serious bug. The Go garbage
collector only examines Go stacks. When Go code calls a
function that is not written in Go, it first calls
syscall.Entersyscall. Entersyscall records the position of
the Go stack pointer and saves a copy of all the registers.
If the garbage collector runs while the thread is executing
the non-Go code, the garbage collector fetches the stack
pointer and registers from the saved location.
Entersyscall saves the registers using the getcontext
function. Unfortunately I didn't consider the possibility
that Entersyscall might itself change a register before
calling getcontext. This only matters for callee-saved
registers, as caller-saved registers would be visible on the
saved stack. And it only matters if Entersyscall is compiled
to save and modify a callee-saved register before it calls
getcontext. And it only matters if a garbage collection
occurs while the non-Go code is executing. And it only
matters if the only copy of a valid Go pointer happens to be
in the callee-saved register when Entersyscall is called.
When all those conditions are true, the Go pointer might get
collected incorrectly, leading to memory corruption.
This patch tries to avoid the problem by splitting
Entersyscall into two functions. The first is a simple
function that just calls getcontext and then calls the rest of
Entersyscall. This should fix the problem, provided the
simple Entersyscall function does not itself modify any
callee-saved registers before calling getcontext. That seems
to be true on the systems I checked. But since the argument
to getcontext is an offset from a TLS variable, it won't be
true on a system which needs to save callee-saved registers in
order to get the address of a TLS variable. I don't know why
any system would work that way, but I don't know how to rule
it out. I think that on any such system this will have to be
implemented in assembler. I can't put the ucontext_t
structure on the stack, because this function can not split
stacks, and the ucontext_t structure is large enough that it
could cause a stack overflow.
From-SVN: r208390
Before this, the heap location used on a 64-bit system was not
available to user-space on arm64, so the "32-bit" strategy ended up
being used. So use somewhere that is available, and for bonus points
is far away from where the kernel allocates address space by default.
From-SVN: r207977
The spans array is allocated in runtime_mallocinit. On a
32-bit system the number of entries in the spans array is
MaxArena32 / PageSize, which (2U << 30) / (1 << 12) == (1 << 19).
So we are allocating an array that can hold 19 bits for an
index that can hold 20 bits. According to the comment in the
function, this is intentional: we only allocate enough spans
(and bitmaps) for a 2G arena, because allocating more would
probably be wasteful.
But since the span index is simply the upper 20 bits of the
memory address, this scheme only works if memory addresses are
limited to the low 2G of memory. That would be OK if we were
careful to enforce it, but we're not. What we are careful to
enforce, in functions like runtime_MHeap_SysAlloc, is that we
always return addresses between the heap's arena_start and
arena_start + MaxArena32.
We generally get away with it because we start allocating just
after the program end, so we only run into trouble with
programs that allocate a lot of memory, enough to get past
address 0x80000000.
This changes the code that computes a span index to subtract
arena_start on 32-bit systems just as we currently do on
64-bit systems.
From-SVN: r206501
I am reliably informed that the architecture name and letter for the
plan9/inferno compilers for 64-bit ARM systems will be "arm64" and "7"
respectively, so let's get that bit in nice and early.
From Michael Hudson-Doyle.
https://codereview.appspot.com/34830045/
From-SVN: r206374
On Solaris, if you do a in-progress connect, and then the
server accepts and closes the socket, the client's later
attempt to complete the connect will fail with EINVAL. Handle
this case by assuming that the connect succeeded. This code
is weird enough that it is implemented as Solaris-only so that
it doesn't hide a real error on a different OS.
See http://golang.org/issue/6828.
From-SVN: r206232
PR go/59506
net: use DialTimeout in TestSelfConnect
Backported from master repository.
This avoids problems with systems that take a long time to
find out nothing is listening, while still testing for the
self-connect misfeature since a self-connect should be fast.
With this we may be able to remove the test for non-Linux
systems.
Tested (on GNU/Linux) by editing selfConnect in
tcpsock_posix.go to always return false and verifying that
TestSelfConnect then fails with and without this change.
Idea from Uros Bizjak.
From-SVN: r206224
When a 386 function returns a struct, it needs to return using
an rtd instruction that pops the hidden struct parameter off
the stack. That wasn't happening.
From-SVN: r205551
In particular this means that the names Getsockname returns are not
truncated to 26 characters.
Fixes issue 6829
https://codereview.appspot.com/31840043/
From-SVN: r205368
