Before this patch, the CrashRecoveryContext was returning -2 upon a signal, like ExecuteAndWait does. This didn't match the behavior on Windows, where the the exception code was returned.
We now return the signal's code, which optionally allows for re-throwing the signal later. Doing so requires all custom handlers to be removed first, through llvm::sys::unregisterHandlers() which we made a public API.
This is part of https://reviews.llvm.org/D70378
For LLVM on *nix systems, the signal handlers are not run on signals
such as SIGINT due to CTRL-C. See sys::CleanupOnSignal. This makes
sense, as such signals are not really crashes. Prior to this change,
this wasn't the case on Windows, however. This patch changes the Windows
behaviour to be consistent with Linux, and adds testing that verifies
this.
The test uses llvm-symbolizer, but any tool with an interactive mode
would do the job.
Fixes https://bugs.llvm.org/show_bug.cgi?id=45754.
Reviewed by: MaskRay, rnk, aganea
Differential Revision: https://reviews.llvm.org/D79847
llvm-ar is using CompareStringOrdinal which is available
only starting with Windows Vista (WINVER 0x600).
Fix this by hoising WindowsSupport.h, which sets _WIN32_WINNT
to 0x0601, up to llvm/include/llvm/Support and use it in llvm-ar.
Patch by Cristian Adam!
Differential revision: https://reviews.llvm.org/D74599
Copy it instead. Otherwise, key registers (such as RBP) may get zeroed
out by the stack unwinder.
Fixes CrashRecoveryTest.DumpStackCleanup with MSVC in release builds.
Reviewed By: stella.stamenova
Differential Revision: https://reviews.llvm.org/D73809
This patch allows for handling a failure inside a CrashRecoveryContext in the same way as the global exception/signal handler. A failure will have the same side-effect, such as cleanup of temporarty file, printing callstack, calling relevant signal handlers, and finally returning an exception code. This is an optional feature, disabled by default.
This is a support patch for D69825.
Differential Revision: https://reviews.llvm.org/D70568
Allow clients of the llvm library to opt-in to one-shot SIGPIPE
handling, instead of forcing them to undo llvm's SIGPIPE handler
registration (which is brittle).
The current behavior is preserved for all llvm-derived tools (except
lldb) by means of a default-`true` flag in the InitLLVM constructor.
This prevents "IO error" crashes in long-lived processes (lldb is the
motivating example) which both a) load llvm as a dynamic library and b)
*really* need to ignore SIGPIPE.
As llvm signal handlers can be installed when calling into libclang
(say, via RemoveFileOnSignal), thereby overriding a previous SIG_IGN for
SIGPIPE, there is no clean way to opt-out of "exit-on-SIGPIPE" in the
current model.
Differential Revision: https://reviews.llvm.org/D70277
This reverts commit 32ce14e55e.
In post-commit review, Pavel pointed out that there's a simpler way to
ignore SIGPIPE in lldb that doesn't rely on llvm's handlers.
Occasionally, during test teardown, LLDB writes to a closed pipe.
Sometimes the communication is inherently unreliable, so LLDB tries to
avoid being killed due to SIGPIPE (it calls `signal(SIGPIPE, SIG_IGN)`).
However, LLVM's default SIGPIPE behavior overrides LLDB's, causing it to
exit with IO_ERR.
Opt LLDB out of the default SIGPIPE behavior. I expect that this will
resolve some LLDB test suite flakiness (tests randomly failing with
IO_ERR) that we've seen since r344372.
rdar://55750240
Differential Revision: https://reviews.llvm.org/D69148
llvm-svn: 375288
Support SIGINFO (and SIGUSR1 for POSIX purposes) to tell what
long-running jobs are doing, as inspired by BSD tools (including on
macOS), by dumping the current PrettyStackTrace.
This adds a new kind of signal handler for non-fatal "info" signals,
similar to the "interrupt" handler that already exists for SIGINT
(Ctrl-C). It then uses that handler to update a "generation count"
managed by the PrettyStackTrace infrastructure, which is then checked
whenever a PrettyStackTraceEntry is pushed or popped on each
thread. If the generation has changed---i.e. if the user has pressed
Ctrl-T---the stack trace is dumped, though unfortunately it can't
include the deepest entry because that one is currently being
constructed/destructed.
https://reviews.llvm.org/D63750
llvm-svn: 365911
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
The idea behind WindowsSupport.h is that it's in the source directory so
that windows.h'isms don't leak out into the larger LLVM project. To that
end, any symbol that references a symbol from windows.h must be in this
private header, and not in a public header.
However, we had some useful utility functions in WindowsSupport.h which
have no dependency on the Windows API, but still only make sense on
Windows. Those functions should be usable outside of Support since there
is no risk of causing a windows.h leak. Although this introduces some
preprocessor logic in some header files, It's not too egregious and it's
better than the alternative of duplicating a ton of code.
Differential Revision: https://reviews.llvm.org/D47662
llvm-svn: 333798
Summary:
Before this patch, signal handling wasn't signal safe. This leads to real-world
crashes. It used ManagedStatic inside of signals, this can allocate and can lead
to unexpected state when a signal occurs during llvm_shutdown (because
llvm_shutdown destroys the ManagedStatic). It also used cl::opt without custom
backing storage. Some de-allocation was performed as well. Acquiring a lock in a
signal handler is also a great way to deadlock.
We can't just disable signals on llvm_shutdown because the signals might do
useful work during that shutdown. We also can't just disable llvm_shutdown for
programs (instead of library uses of clang) because we'd have to then mark the
pointers as not leaked and make sure all the ManagedStatic uses are OK to leak
and remain so.
Move all of the code to lock-free datastructures instead, and avoid having any
of them in an inconsistent state. I'm not trying to be fancy, I'm not using any
explicit memory order because this code isn't hot. The only purpose of the
atomics is to guarantee that a signal firing on the same or a different thread
doesn't see an inconsistent state and crash. In some cases we might miss some
state (for example, we might fail to delete a temporary file), but that's fine.
Note that I haven't touched any of the backtrace support despite it not
technically being totally signal-safe. When that code is called we know
something bad is up and we don't expect to continue execution, so calling
something that e.g. sets errno is the least of our problems.
A similar patch should be applied to lib/Support/Windows/Signals.inc, but that
can be done separately.
Fix r332428 which I reverted in r332429. I originally used double-wide CAS
because I was lazy, but some platforms use a runtime function for that which
thankfully failed to link (it would have been bad for signal handlers
otherwise). I use a separate flag to guard the data instead.
<rdar://problem/28010281>
Reviewers: dexonsmith
Subscribers: steven_wu, llvm-commits
llvm-svn: 332496
Summary:
Before this patch, signal handling wasn't signal safe. This leads to real-world
crashes. It used ManagedStatic inside of signals, this can allocate and can lead
to unexpected state when a signal occurs during llvm_shutdown (because
llvm_shutdown destroys the ManagedStatic). It also used cl::opt without custom
backing storage. Some de-allocation was performed as well. Acquiring a lock in a
signal handler is also a great way to deadlock.
We can't just disable signals on llvm_shutdown because the signals might do
useful work during that shutdown. We also can't just disable llvm_shutdown for
programs (instead of library uses of clang) because we'd have to then mark the
pointers as not leaked and make sure all the ManagedStatic uses are OK to leak
and remain so.
Move all of the code to lock-free datastructures instead, and avoid having any
of them in an inconsistent state. I'm not trying to be fancy, I'm not using any
explicit memory order because this code isn't hot. The only purpose of the
atomics is to guarantee that a signal firing on the same or a different thread
doesn't see an inconsistent state and crash. In some cases we might miss some
state (for example, we might fail to delete a temporary file), but that's fine.
Note that I haven't touched any of the backtrace support despite it not
technically being totally signal-safe. When that code is called we know
something bad is up and we don't expect to continue execution, so calling
something that e.g. sets errno is the least of our problems.
A similar patch should be applied to lib/Support/Windows/Signals.inc, but that
can be done separately.
<rdar://problem/28010281>
Reviewers: dexonsmith
Subscribers: aheejin, llvm-commits
Differential Revision: https://reviews.llvm.org/D46858
llvm-svn: 332428
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.
Patch produced by
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done
Differential Revision: https://reviews.llvm.org/D46290
llvm-svn: 331272
The commit in SVN r310001 that added support for this actually didn't
use the right struct field for the frame pointer - for ARM, there is
no register named Fp in the CONTEXT struct. On Windows, the R11
register is used as frame pointer.
Differential Revision: https://reviews.llvm.org/D45590
llvm-svn: 329991
These used to be set in the old autoconf build, but the cmake build has had a
"TODO: actually check for these" comment since it was checked in, and they
were set to 1 on mingw unconditionally. It seems safe to say that they always
exist under mingw, so just remove them and assume they're set exactly when on
mingw (with msvc, we use `pragma comment` instead of linking these via flags).
llvm-svn: 328992
looking for it along $PATH. This allows installs of LLVM tools outside of
$PATH to find the symbolizer and produce pretty backtraces if they crash.
llvm-svn: 272232
In the current implementation compiler only prints stack trace
to console after crash. This patch adds saving of minidump
files which contain a useful subset of the information for
further debugging.
Differential Revision: http://reviews.llvm.org/D18216
llvm-svn: 268519
This reverts commit r254363.
load64BitDebugHelp() has the side effect of loading dbghelp and setting
globals. It should be called in no-asserts builds as well as debug
builds.
llvm_unreachable is also not appropriate here, since we actually want to
return if dbghelp couldn't be loaded in a non-asserts build.
llvm-svn: 257384
Summary:
llvm-symbolizer understands both PDBs and DWARF, so it is more likely to
succeed at symbolization. If llvm-symbolizer is unavailable, we will
fall back to dbghelp. This also makes our crash traces more similar
between Windows and Linux.
Reviewers: Bigcheese, zturner, chapuni
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D12884
llvm-svn: 252118
And expose it in Signals.h, allowing clients to call it directly,
possibly LLVMErrorHandler which currently calls RunInterruptHandlers
but not RunSignalHandlers, thus for example not printing the stack
backtrace on Unixish OSes. On Windows it does happen because
RunInterruptHandlers ends up calling the callbacks as well via
Cleanup(). This difference in behaviour and code structures in
*/Signals.inc should be patched in the future.
llvm-svn: 242936
Move CallBacksToRun into the common Signals.cpp, create RunCallBacksToRun()
and use these in both Unix/Signals.inc and Windows/Signals.inc.
Lots of potential code to be merged here.
llvm-svn: 242925
This patch changes linkage with dbghlp.dll for clang from static (at load time)
to on demand (at the first use of required functions). Clang uses dbghlp.dll
only in minor use-cases. First of all in case of crash and in case of plugin load.
The dbghlp.dll library can be absent on system. In this case clang will fail
to load. With lazy load of dbghlp.dll clang can work even if dbghlp.dll
is not available.
Differential Revision: http://reviews.llvm.org/D10737
llvm-svn: 241271
The current crash reporting on Mac OS is only disabled via an environment variable.
This adds a boolean (default false) which can also disable crash reporting.
The only client right now is the unittests which don't ever want crash reporting, but do want to detect killed programs.
Reduces the time to run the APFloat unittests on my machine from
[----------] 47 tests from APFloatTest (51250 ms total)
to
[----------] 47 tests from APFloatTest (765 ms total)
Reviewed by Reid Kleckner and Justin Bogner
llvm-svn: 234353
This will be followed by a change on the clang side to update
the only user of this function with the new version.
Differential Revision: http://reviews.llvm.org/D8074
Reviewed By: Reid Kleckner
llvm-svn: 231392
The first element of STACKFRAME64 is a struct and Clang wants us to put
braces around it's initialization. Instead, drop the zero. The result
should be the same.
llvm-svn: 231387
Alexandre Ganea