The find-dynamic-unwind-info callback registration APIs in libunwind
limit the number of callbacks that can be registered. If we use multiple
UnwindInfoManager instances, each with their own own callback function
(as was the case prior to this patch) we can quickly exceed this limit
(see https://github.com/llvm/llvm-project/issues/126611).
This patch updates the UnwindInfoManager class to use a singleton
pattern, with the single instance shared between all LLVM JITs in the
process.
This change does _not_ apply to compact unwind info registered through
the ORC runtime (which currently installs its own callbacks).
As a bonus this change eliminates the need to load an IR "bouncer"
module to supply the unique callback for each instance, so support for
compact-unwind can be extended to the llvm-jitlink tools (which does not
support adding IR).
Re-enables compact-unwind support in JITLink, which was reverted in b04847b427d
due to buildbot failures.
The underlying cause for the failures on the buildbots was the lack of
compact-unwind registration support on older Darwin OSes. Since the
CompactUnwindManager pass now removes eh-frames by default we were left with
unwind-info that could not be registered. On x86-64, where eh-frame info is
produced by default the solution is to fall back to using eh-frames. On arm64
we simply can't support exceptions on older OSes.
This patch updates the EHFrameRegistrationPlugin to remove the compact-unwind
section (__LD,__compact_unwind) when installed, forcing use of eh-frames when
the EHFrameRegistrationPlugin is used. In LLJIT, the EHFrameRegistrationPlugin
continues to be used for all non-Darwin platform, and will be added on Darwin
platforms when the a CompactUnwindRegistrationPlugin instance can't be created
(e.g. due to missing support for compact-unwind info registration).
The lit.cfg.py script is updated to check whether the host OSes default unwind
info supports JIT registration, allowing tests to be disabled for older Darwin
OSes on arm64.
This reverts commit d6524c8dfa37634257050ca71d16e117b802181c. This
reverts commit b1bd73700a1fb6f450e0f6f9c405a9c8bde2cae7.
This was causing bot failures on Darwin
https://green.lab.llvm.org/job/llvm.org/job/clang-stage1-cmake-RA-incremental/7315/
Clang.Interpreter.simple-exception.cpp
Clang-Unit.Interpreter/ExceptionTests/_/ClangReplInterpreterExceptionTests/0.1
LLVM.ExecutionEngine/OrcLazy.minimal-throw-catch.ll
https://green.lab.llvm.org/job/llvm.org/job/clang-stage1-RA/3415/
ORC-x86_64-darwin.TestCases/Darwin/Generic.exceptions.cpp
ORC-x86_64-darwin.TestCases/Darwin/x86-64.lljit-ehframe.cpp
This reapplies 4f0325873fa (and follow up patches 26fc07d5d88, a001cc0e6cdc,
c9bc242e387, and fd174f0ff3e), which were reverted in 212cdc9a377 to
investigate bot failures (e.g.
https://lab.llvm.org/buildbot/#/builders/108/builds/8502)
The fix to address the bot failures was landed in d0052ebbe2e. This patch also
restricts construction of the UnwindInfoManager object to Apple platforms (as
it won't be used on other platforms).
This reverts 4f0325873faccfbe171bae4babceb65975ca892e and follow-up patches
(see below) while I investigate some ongoing failures on the buildbots.
---
Revert "[clang-repl] Try to XFAIL testcase on arm32 without affecting arm64
darwin."
This reverts commit fd174f0ff3e793fe96a6663b1488ed159cfe042f.
Revert "[clang-repl] The simple-exception test now passes on arm64-darwin."
This reverts commit c9bc242e387f4a4a3dfcd86561f3ec0ca8a72d62.
Revert "[ORC] Destroy defunct MaterializationUnits outside the session lock."
This reverts commit a001cc0e6cdcfa672b8aff9ce6d14782bb96356a.
Revert "[ORC] Add explicit narrowing casts to fix build errors."
This reverts commit 26fc07d5d88760ad659599184fd10181287d2d9e.
Revert "[ORC] Enable JIT support for the compact-unwind frame info format on
Darwin."
This reverts commit 4f0325873faccfbe171bae4babceb65975ca892e.
For Darwin/arm64 (including Apple Silicon Macs) this will enable exception
handling and stack unwinding in JIT'd code.
Darwin supports two unwind-info formats: DWARF eh-frames and compact-unwind. On
Darwin/x86-64 compilers usually produce both by default, and ORC supported
exceptions and unwinding via eh-frames (same as on Linux), discarding the
redundant compact-unwind info. On Darwin/arm64 compilers typically default to
producing compact-unwind only, with DWARF eh-frames as a fallback for functions
that can't be described in compact-unwind. Since ORC did not previously support
the compact-unwind format and eh-frames were not present ORC was unable to
handle exceptions or unwinding by default in Darwin/arm64 JIT'd code.
This patch enables support for the compact-unwind-info format, and contains
three major moving parts:
(1) The JITLink CompactUnwindManager class is responsible for transforming the
__compact_unwind records produced by the linker into the __unwind_info
tables that libunwind parses during unwinding. To enable this the
CompactUnwindManager class provides three JITLink passes: The
prepareForPrune pass that splits the __compact_unwind section into
single-record blocks, allowing unused records to be dead-stripped; the
processAndReserveUnwindInfo pass that reserves space for the final
__unwind_info section, and the writeUnwindInfo pass that writes the
__unwind_info section.
(2) The OrcTargetProcess UnwindInfoManager class maintains a table of
registered JIT'd __unwind_info and __eh_frame sections, and handles
requests from libunwind for unwind info sections (by registering a callback
with libunwind's __unw_add_find_dynamic_unwind_sections function).
(3) The Orc UnwindInfoRegistrationPlugin, which scans LinkGraphs for
__unwind_info and __eh_frame sections to register with the
UnwindInfoManager.
This commit adds the CompactUnwindManager passes to the default JITLink
pipelines for Darwin/arm64 and Darwin/x86-64, and UnwindInfoManager intances to
the SelfExecutorProcessControl class (when built for apple platforms) and the
llvm-jitlink-executor tool.
The LLJIT class will now create an UnwindInfoRegistrationPlugin when targeting
a process running on Darwin if it detects that an UnwindInfoManager is
available to handle the registrations.
The ORC runtime macho_platform class already supported libunwind callbacks, so
out-of-process execution and unwinding support will work when loading the ORC
runtime.
The llvm-jitlink tool will only support compact-unwind when the orc-runtime is
loaded, as the UnwindInfoRegistrationPlugin requires access to an IR compiler
to load a helper module and llvm-jitlink does not provide an IR compiler.
Make EPCGenericMemoryAccess the default implementation for the MemoryAccess
object in SimpleRemoteEPC, and add support for the WritePointers operation to
OrcTargetProcess (previously this operation was unimplemented and would have
triggered an error if accessed in a remote-JIT setup).
No testcase yet: This functionality requires cross-process JITing to test (or a
much more elaborate unit-test setup). It can be tested once the new top-level
ORC runtime project lands.
By using bootstrap symbols to communicate these addresseses, rather than dlsym
lookups, we no longer need them to be exported from the main executable. On ELF,
where symbols aren't exported from the main executable by default, this
eliminates a common source of missing symbol errors and allows for smaller
executables (if exports from the main executable aren't otherwise needed and
can be removed).
Introduces COFFVCRuntimeBootstrapper that loads/initialize vc runtime libraries. In COFF, we *must* jit-link vc runtime libraries as COFF relocation types have no proper way to deal with out-of-reach data symbols ragardless of linking mode. (even dynamic version msvcrt.lib have tons of static data symbols that must be jit-linked) This class tries to load vc runtime library files from msvc installations with an option to override the path.
There are some complications when dealing with static version of vc runtimes. First, they need static initializers to be ran that requires COFFPlatform support but orc runtime will not be usable before vc runtimes are fully initialized. (as orc runtime will use msvc stl libraries) COFFPlatform that will be introduced in a following up patch will collect static initializers and run them manually in host before boostrapping itself. So, the user will have to do the following.
1. Create COFFPlatform that addes static initializer collecting passes.
2. LoadVCRuntime
3. InitializeVCRuntime
4. COFFPlatform.bootstrap()
Second, the internal crt initialization function had to be reimplemented in orc side. There are other ways of doing this, but this is the simplest implementation that makes platform fully responsible for static initializer. The complication comes from the fact that crt initialization functions (such as acrt_initialize or dllmain_crt_process_attach) actually run all static initializers by traversing from `__xi_a` symbol to `__xi_z`. This requires symbols to be contiguously allocated in sections alphabetically sorted in memory, which is not possible right now and not practical in jit setting. We might ignore emission of `__xi_a` and `__xi_z` symbol and allocate them ourselves, but we have to take extra care after orc runtime boostrap has been done -- as that point orc runtime should be the one running the static initializers.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D130456
...with more fixes.
The original patch was reverted in 3e9cc543f22 due to bot failures caused by
a missing dependence on librt. That issue was fixed in 32d8d23cd0, but that
commit also broke sanitizer bots due to a bug in SimplePackedSerialization:
empty ArrayRef<char>s triggered a zero-byte memcpy from a null source. The
ArrayRef<char> serialization issue was fixed in 67220c2ad7, and this patch has
also been updated with a new custom SharedMemorySegFinalizeRequest message that
should avoid serializing empty ArrayRefs in the first place.
https://reviews.llvm.org/D128544
This reverts commit 32d8d23cd0b2d4d010eb112dfe5216f11b2681f9.
Reason: Broke the UBSan buildbots. See more details on Phabricator:
https://reviews.llvm.org/D128544
The original commit was reverted in 3e9cc543f223 due to buildbot failures, which
should be fixed by the addition of dependencies on librt.
Differential Revision: https://reviews.llvm.org/D128544
This is an implementation of orc::MemoryMapper that maps shared memory
pages in both executor and controller process and writes directly to
them avoiding transferring content over EPC. All allocations are properly
deinitialized automatically on the executor side at shutdown by the
ExecutorSharedMemoryMapperService.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D128544
This reintroduces "[ORC] Introduce EPCGenericRTDyldMemoryManager."
(bef55a2b47a938ef35cbd7b61a1e5fa74e68c9ed) and "[lli] Add ChildTarget dependence
on OrcTargetProcess library." (7a219d801bf2c3006482cf3cbd3170b3b4ea2e1b) which were
reverted in 99951a56842d8e4cd0706cd17a04f77b5d0f6dd0 due to bot failures.
The root cause of the bot failures should be fixed by "[ORC] Fix uninitialized
variable." (0371049277912afc201da721fa659ecef7ab7fba) and "[ORC] Wait for
handleDisconnect to complete in SimpleRemoteEPC::disconnect."
(320832cc9b7e7fea5fc8afbed75c34c4a43287ba).
This reverts commit bef55a2b47a938ef35cbd7b61a1e5fa74e68c9ed while I investigate
failures on some bots. Also reverts "[lli] Add ChildTarget dependence on
OrcTargetProcess library." (7a219d801bf2c3006482cf3cbd3170b3b4ea2e1b) which was
a fallow-up to bef55a2b47a.
EPCGenericRTDyldMemoryMnaager is an EPC-based implementation of the
RuntimeDyld::MemoryManager interface. It enables remote-JITing via EPC (backed
by a SimpleExecutorMemoryManager instance on the executor side) for RuntimeDyld
clients.
The lli and lli-child-target tools are updated to use SimpleRemoteEPC and
SimpleRemoteEPCServer (rather than OrcRemoteTargetClient/Server), and
EPCGenericRTDyldMemoryManager for MCJIT tests.
By enabling remote-JITing for MCJIT and RuntimeDyld-based ORC clients,
EPCGenericRTDyldMemoryManager allows us to deprecate older remote-JITing
support, including OrcTargetClient/Server, OrcRPCExecutorProcessControl, and the
Orc RPC system itself. These will be removed in future patches.
EPCGenericDylibManager provides an interface for loading dylibs and looking up
symbols in the executor, implemented using EPC-calls to functions in the
executor.
SimpleExecutorDylibManager is an executor-side service that provides the
functions used by EPCGenericDylibManager.
SimpleRemoteEPC is updated to use an EPCGenericDylibManager instance to
implement the ExecutorProcessControl loadDylib and lookup methods. In a future
commit these methods will be removed, and clients updated to use
EPCGenericDylibManagers directly.
Finalization and deallocation actions are a key part of the upcoming
JITLinkMemoryManager redesign: They generalize the existing finalization and
deallocate concepts (basically "copy-and-mprotect", and "munmap") to include
support for arbitrary registration and deregistration of parts of JIT linked
code. This allows us to register and deregister eh-frames, TLV sections,
language metadata, etc. using regular memory management calls with no additional
IPC/RPC overhead, which should both improve JIT performance and simplify
interactions between ORC and the ORC runtime.
The SimpleExecutorMemoryManager class provides executor-side support for memory
management operations, including finalization and deallocation actions.
This support is being added in advance of the rest of the memory manager
redesign as it will simplify the introduction of an EPC based
RuntimeDyld::MemoryManager (since eh-frame registration/deregistration will be
expressible as actions). The new RuntimeDyld::MemoryManager will in turn allow
us to remove older remote allocators that are blocking the rest of the memory
manager changes.
This is a small first step towards reorganization of the ORC libraries:
Declarations for types and function names (as strings) to be found in the
"ORC runtime bootstrap" set are moved into OrcRTBridge.h / OrcRTBridge.cpp.
The current implementation of the "ORC runtime bootstrap" functions is moved
into OrcRTBootstrap.h and OrcRTBootstrap.cpp. It is likely that this code will
eventually be moved into ORT-RT proper (in compiler RT).
The immediate goal of this change is to make these bootstrap functions usable
for clients other than SimpleRemoteEPC/SimpleRemoteEPCServer. The first planned
client is a new RuntimeDyld::MemoryManager that will run over EPC, which will
allow us to remove the old OrcRemoteTarget code.
