This CL adds support of precise stack scan using stack maps to
the runtime. The stack maps are generated by the compiler (if
supported). Each safepoint is associated with a (real or dummy)
landing pad, and its "type info" in the exception table is a
pointer to the stack map. When a stack is scanned, the stack map
is found by the stack unwinding code by inspecting the exception
table (LSDA).
For precise stack scan we need to unwind the stack. There are
three cases:
- If a goroutine is scanning its own stack, it can unwind the
stack and scan the frames.
- If a goroutine is scanning another, stopped, goroutine, it
cannot directly unwind the target stack. We handle this by
switching (runtime.gogo) to the target g, letting it unwind
and scan the stack, and switch back.
- If we are scanning a goroutine that is blocked in a syscall,
we send a signal to the target goroutine's thread, and let the
signal handler unwind and scan the stack. Extra care is needed
as this races with enter/exit syscall.
Currently this is only implemented on linux.
Reviewed-on: https://go-review.googlesource.com/c/140518
From-SVN: r266832
In buildmodeinit, the c-archive buildmode is flagged as invalid
on linux/ppc64 for gccgo when it should be valid. This happens
because the check against the gccgo flag is done after the checks
for valid GOOS/GOARCH pairs instead of before as is done for all
other buildmode cases in this switch. This corrects the problem and
allows several of the gccgo gotools testcases to pass on linux/ppc64.
Updates #29046
Reviewed-on: https://go-review.googlesource.com/c/152137
From-SVN: r266764
For inlined function bodies we're going to need to refer to variables,
so change the existing export data to add a '$' to names that look
like identifiers: true, false, nil, convert.
While we're here drop an unnecessary space character after operators.
Reviewed-on: https://go-review.googlesource.com/c/150067
From-SVN: r266529
Create a framework for putting function bodies in export data. At
present only empty functions will be put there, and they will be
ignored on import. Later patches will get this to the point of
supporting inlining of (some) functions defined in other packages.
Reviewed-on: https://go-review.googlesource.com/c/150061
From-SVN: r266490
PR go/88060
syscall: always define _AT_FDCWD and IPv6MTUInfo
They aren't defined by old versions of glibc, but are required by the
code in syscall_linux.go.
Reviewed-on: https://go-review.googlesource.com/c/150697
From-SVN: r266333
The code to implement new-style gccgo name mangling had a recipe that
didn't quite match the one in the compiler (incorrect handling for
'.'). This showed up as a failure in the gotools cgo test if the
directory containing the test run included a "." character.
Reviewed-on: https://go-review.googlesource.com/c/147917
From-SVN: r265981
PR bootstrap/82856
libgo: update to autoconf 2.69 and automake 1.15.1
Initial patch from Joseph Myers.
Reviewed-on: https://go-review.googlesource.com/c/146417
From-SVN: r265701
Fix asm name directive for the C version of log/syslog.syslog_c,
which didn't get included in the recent name mangling change.
Reviewed-on: https://go-review.googlesource.com/c/145017
From-SVN: r265533
The current implementation of Gogo::pkgpath_for_symbol was written in
a way that allowed two distinct package paths to map to the same
symbol, which could cause collisions at link- time or compile-time.
Switch to a better mangling scheme to insure that we get a unique
packagepath symbol for each package. In the new scheme instead of having
separate mangling schemes for identifiers and package paths, the
main identifier mangler ("go_encode_id") now handles mangling of
both packagepath characters and identifier characters.
The new mangling scheme is more intrusive: "foo/bar.Baz" is mangled as
"foo..z2fbar.Baz" instead of "foo_bar.Baz". To mitigate this, this
patch also adds a demangling capability so that function names
returned from runtime.CallersFrames are converted back to their
original unmangled form.
Changing the pkgpath_for_symbol scheme requires updating a number of
//go:linkname directives and C "__asm__" directives to match the new
scheme, as well as updating the 'gotest' driver (which makes
assumptions about the correct mapping from pkgpath symbol to package
name).
Fixesgolang/go#27534.
Reviewed-on: https://go-review.googlesource.com/c/135455
From-SVN: r265510
PR go/87661
runtime: remove unused armArch, hwcap and hardDiv
After CL 140057 these are only written but never read in gccgo.
Reviewed-on: https://go-review.googlesource.com/c/141077
From-SVN: r265439
Introduce a new "types" command to the export data to record the
number of types and the size of their export data. It is immediately
followed by new "type" commands that can be indexed. Parse all the
exported types immediately so that we register them, but parse other
type data only as needed.
Reviewed-on: https://go-review.googlesource.com/c/143022
From-SVN: r265409
Previously when export data referred to a type that was not defined in
a directly imported package, we would write the package name as
additional information in the type's export data. That approach
required all type information to be read in order. This patch changes
the compiler to find all references to indirectly imported packages,
and write them out as an indirectimport line in the import data. This
will permit us to read exported type data out of order.
The type traversal used to find indirect imports is a little more
complicated than necessary in preparation for later patches in this
series.
Reviewed-on: https://go-review.googlesource.com/c/143020
From-SVN: r265296
The export data, which is approximately readable and looks something
like Go, was first implemented back when Go still used semicolons.
Drop the semicolons, to make it look slightly more Go like and make it
slightly smaller.
This updates the compiler and the gccgoimporter package.
This introduces a new version of the export data. There are going to
be more changes to the export data, so this version is still subject
to change.
Reviewed-on: https://go-review.googlesource.com/c/143018
From-SVN: r265284
LLVM doesn't support non-call exception. This test was passing
more or less by luck: if the faulting instruction is between two
calls with the same landing pad (in instruction layout order,
not the program's logic order), it generates a merged PC range
that covers the faulting instruction. If the instruction layout
order changes, or it uses two different (but may be degenerate)
landing pads, this doesn't work.
Reviewed-on: https://go-review.googlesource.com/c/140517
From-SVN: r264985
Use inline assembly in the implementation of internal_cpu.xgetbv as
opposed to a call to the intrinsic _xgetbv(), since non-gcc compilers
(e.g. clang) may or may not have support for it.
Reviewed-on: https://go-review.googlesource.com/c/140137
From-SVN: r264882
This reportedly happens on CentOS 5.11. The real code will work fine;
this test is assuming that the unexported slice function will handle
the splice, but if pipe2 does not work then it doesn't. The relevant
code in internal/poll/splice_linux.go says "Falling back to pipe is
possible, but prior to 2.6.29 splice returns -EAGAIN instead of 0 when
the connection is closed."
Reviewed-on: https://go-review.googlesource.com/138838
From-SVN: r264793
This is enough to let libgo build when configured using
--with-multilib-list=m64,m32,mx32. I don't have an x32-enabled kernel
so I haven't tested whether it executes correctly.
For https://gcc.gnu.org/PR87470
Reviewed-on: https://go-review.googlesource.com/138817
From-SVN: r264772
Rewrite the arm64 AES hashing code from gc assembler to C code using
intrinsics. The resulting code generates the same hash code for the
same input as the gc code--that doesn't matter as such, but testing it
ensures that the C code does something useful.
Reviewed-on: https://go-review.googlesource.com/138535
From-SVN: r264771
On Alpha GNU/Linux there is no geteuid system call, there is only
getresuid. The raw geteuid system call is only used for testing, so
just skip the test if it's not available.
Reviewed-on: https://go-review.googlesource.com/137655
From-SVN: r264647
In internal/bytealg correct a +build tag to never build indexbyte_generic.go
for the gofrontend, where we always use indexbyte_native.go.
For internal/cpu let the Makefile define CacheLineSize using goarch.sh,
rather than trying to enumerate all the possibilities in cpu_ARCH.go files.
In internal/poll call the C fcntl function rather than using SYS_FCNTL.
Change mksysinfo.sh to ensure that F_GETPIPE_SZ is always defined,
and check that in internal/poll.
Reviewed-on: https://go-review.googlesource.com/137256
From-SVN: r264572
This permits TestScript to work when gccgo is not installed.
Previous testing was using a previously installed gccgo, not the newly
built one.
This revealed that the testing of whether an internal package is
permitted was incorrect for standard library packages, since the
uninstalled gccgo can see internal packages in the uninstalled libgo.
Fix the internal package tests.
This permitted removing a couple of gccgo-specific changes in the
testsuite.
Reviewed-on: https://go-review.googlesource.com/137255
From-SVN: r264570
Reviewed-on: https://go-review.googlesource.com/136435
gotools/:
* Makefile.am (mostlyclean-local): Run chmod on check-go-dir to
make sure it is writable.
(check-go-tools): Likewise.
(check-vet): Copy internal/objabi to check-vet-dir.
* Makefile.in: Rebuild.
From-SVN: r264546
In 1.11 writebarrierptr is going away, so change the compiler to call
gcWriteBarrier instead. We weren't using gcWriteBarrier before;
adjust the implementation to use the putFast method.
This revealed a problem in the kickoff function. When using cgo,
kickoff can be called on the g0 of an m allocated by newExtraM. In
that case the m will generally have a p, but systemstack may be called
by wbBufFlush as part of flushing the write barrier buffer. At that
point the buffer is full, so we can not do a write barrier. So adjust
the existing code in kickoff so that in the case where we are g0,
don't do any write barrier at all.
Reviewed-on: https://go-review.googlesource.com/131395
From-SVN: r264295
In the sweep code we can sometimes see incorrect counts when
conservative stack scanning causes us to grey an object that we
earlier decided could be freed. We already ignored this check, but
adjust this case to maintain correct span counts when it happens.
This gives us slightly more correct numbers in MemStats, and helps
avoid a rare failure in TestReadMemStats.
Also fix the free index, and cope with finding a full span when
allocating a new one.
Reviewed-on: https://go-review.googlesource.com/134216
From-SVN: r264294
Unlike the gc runtime, libgo stores traceback information in location
structs, which contain strings. Therefore, copying location structs
around appears to require write barriers, although in fact write
barriers are never important because the strings are never allocated
in Go memory. They come from libbacktrace.
Some of the generated write barriers come at times when write barriers
are not permitted. For example, exitsyscall, marked
nowritebarrierrec, calls exitsyscallfast which calls traceGoSysExit
which calls traceEvent which calls traceStackID which calls
trace.stackTab.put which copies location values into memory allocated
by tab.newStack. This write barrier can be invoked when there is no
p, causing a crash.
This change fixes the problem by ensuring that location values are
copied around in the tracing code with no write barriers.
This was found by fixing the compiler to fully implement
//go:nowritebarrierrec; CL to follow.
Reviewed-on: https://go-review.googlesource.com/134226
From-SVN: r264282
To reduce the amount of time spent in write barrier processing
(specifically runtime.bulkBarrierPreWrite), add support for building a
'GC roots index', basically a sorted list of all roots, so as to
allow more efficient lookups of gcdata structures for globals. The
previous implementation worked on the raw (unsorted) roots list
itself, which did not scale well.
Reviewed-on: https://go-review.googlesource.com/132595
From-SVN: r264276
This is the gofrontend version of https://golang.org/cl/91796.
This is part of that CL, just the compiler change and required runtime
changes, in preparation for updating libgo to 1.11.
Relevant part of original CL description:
The hmap field in the maptype is only used by the runtime to check the sizes of
the hmap structure created by the compiler and runtime agree.
Comments are already present about the hmap structure definitions in the
compiler and runtime needing to be in sync.
Reviewed-on: https://go-review.googlesource.com/130976
From-SVN: r263941
This is a port of https://golang.org/cl/109596 to the gofrontend, in
preparation for updating libgo to 1.11.
Original CL description:
getcallersp is intrinsified, and so the dummy arg is no longer
needed. Remove it, as well as a few dummy args that are solely
to feed getcallersp.
Reviewed-on: https://go-review.googlesource.com/131116
From-SVN: r263840
Fix up the testing package to insure that execution traces
work properly (e.g. "-test.trace=<XXX>" command line option). The
call to stop tracing and emit the output file was stubbed out.
Reviewed-on: https://go-review.googlesource.com/128275
From-SVN: r263363
When writing stack frames to the pprof CPU profile machinery, it is
very important to insure that the frames emitted do not contain any
frames corresponding to artifacts of the profiling process itself
(signal handlers, sigprof, etc). This patch changes runtime.sigprof to
strip out those frames from the raw stack generated by
"runtime.callers".
Fixesgolang/go#26595.
Reviewed-on: https://go-review.googlesource.com/126175
From-SVN: r263035
The libffi library doesn't understand zero-sized objects.
When we see a zero-sized field in a struct, just skip it when
converting to the FFI data structures. There is no value to pass in
any case, so not telling libffi about the field doesn't affect
anything.
The test case for this is https://golang.org/cl/123316.
Fixesgolang/go#26335
Reviewed-on: https://go-review.googlesource.com/123335
From-SVN: r262651
PR go/86331
os: check return value as well as error from waitid
https://gcc.gnu.org/PR86331 indicates that if a signal handler runs it
is possible for syscall.Syscall6 to return a non-zero errno value even
if no error occurs. That is a problem in general, but this fix will
let us work around the general problem for the specific case of
calling waitid.
Reviewed-on: https://go-review.googlesource.com/121595
From-SVN: r262313
USING_SPLIT_STACK is configured as defined/undefined, not 0/1.
Most of the places test USING_SPLIT_STACK with #ifdef, with a
few exceptions. This CL fixes the exceptions.
Reviewed-on: https://go-review.googlesource.com/120596
From-SVN: r261980
