Since functions exported from DLLs are type-erased, before this patch I
was seeing the new Clang 19 warning `-Wcast-function-type-mismatch`.
This happens when building LLVM on Windows.
Following discussion in
593f708118 (commitcomment-143905744)
LoadLibraryW will lookup dlls in user directories if its search path is
left unrestricted. This is a security vulnerability as one can name a
shared library the same as that of a system dll in order to run
arbitrary code when the shared library is loaded from the path in a user
directory. This change modifies it to only search within sys32 when
loading dbghelp.dll.
When the environment LLVM_ENABLE_SYMBOLIZER_MARKUP is set, if
llvm-symbolizer fails or is disabled, this change will print a backtrace
in llvm-symbolizer markup instead of falling back to in-process
symbolization mechanisms.
This allows llvm-symbolizer to be run on the output later to produce a
high quality backtrace, even for fully-stripped LLVM utilities.
Reviewed By: mcgrathr
Differential Revision: https://reviews.llvm.org/D139750
This fixes the following warning on Windows with latest Clang:
```
[160/3057] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/Signals.cpp.obj
In file included from C:/git/llvm-project/llvm/lib/Support/Signals.cpp:260:
C:/git/llvm-project/llvm/lib/Support/Windows/Signals.inc(834,15): warning: comparison of integers of different signs: 'int' and 'unsigned int' [-Wsign-compare]
if (RetCode == (0xE0000000 | EX_IOERR))
~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~
1 warning generated.```
Apply clang-format on llvm/lib/Support/Windows/ and llvm/lib/Support/Unix/ since .inc files in these folders aren't picked up by default. Eventually we need to add this extension in the monorepo .clang-format file.
Differential Revision: https://reviews.llvm.org/D138714
LLVM contains a helpful function for getting the size of a C-style
array: `llvm::array_lengthof`. This is useful prior to C++17, but not as
helpful for C++17 or later: `std::size` already has support for C-style
arrays.
Change call sites to use `std::size` instead.
Differential Revision: https://reviews.llvm.org/D133429
Prevents deadlock between MiniDumpWriteDump and
CryptAcquireContextW (called via fs::createTemporaryFile) in
WriteWindowsDumpFile.
However, there's no guarantee that deadlock can't still occur between
MiniDumpWriteDump and some other Win32 API call. But that would appear
to be the "accepted" risk of using MiniDumpWriteDump in this manner.
Differential Revision: https://reviews.llvm.org/D129004
Currently the backtrace emitted on windows when llvm-symbolizer is not
available includes addresses which cannot be easily decoded because
the addresses have the containing module's run-time base address added
into them, but we don't know what those base addresses are. This
change emits a module offset rather than an address.
There are a couple of related changes which were included as a result
of the review discussion for this patch:
- I have also removed the parameter printing as it adds noise to the
dump and doesn't seem useful.
- I have added the exception code to the backtrace.
Differential Review: https://reviews.llvm.org/D127915
On Windows certain function from `Signals.h` require that `DbgHelp.dll` is loaded. This typically happens when the main program calls `llvm::InitLLVM`, however in some cases main program doesn't do that (e.g. when the application is using LLDB via `liblldb.dll`). This patch adds a safe guard to prevent crashes. More discussion in
https://reviews.llvm.org/D119009.
Reviewed By: aganea
Differential Revision: https://reviews.llvm.org/D119181
This reverts commit ef8206320769ad31422a803a0d6de6077fd231d2.
- It conflicts with the existing llvm::size in STLExtras, which will now
never be called.
- Calling it without llvm:: breaks C++17 compat
We can build it with -Werror=global-constructors now. This helps
in situation where libSupport is embedded as a shared library,
potential with dlopen/dlclose scenario, and when command-line
parsing or other facilities may not be involved. Avoiding the
implicit construction of these cl::opt can avoid double-registration
issues and other kind of behavior.
Reviewed By: lattner, jpienaar
Differential Revision: https://reviews.llvm.org/D105959
We can build it with -Werror=global-constructors now. This helps
in situation where libSupport is embedded as a shared library,
potential with dlopen/dlclose scenario, and when command-line
parsing or other facilities may not be involved. Avoiding the
implicit construction of these cl::opt can avoid double-registration
issues and other kind of behavior.
Reviewed By: lattner, jpienaar
Differential Revision: https://reviews.llvm.org/D105959
We can build it with -Werror=global-constructors now. This helps
in situation where libSupport is embedded as a shared library,
potential with dlopen/dlclose scenario, and when command-line
parsing or other facilities may not be involved. Avoiding the
implicit construction of these cl::opt can avoid double-registration
issues and other kind of behavior.
Reviewed By: lattner, jpienaar
Differential Revision: https://reviews.llvm.org/D105959
This allows frontend and backend diagnostic files to all go into the
same place. Have it control the Windows (mini-)dump location.
Differential Revision: https://reviews.llvm.org/D99199
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 32ce14e55e5a99dd99c3b4fd4bd0ccaaf2948c30.
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
