They are already implicitly convertible to the underlying type, but that
doesn't work in some contexts, and it can be useful to get the
underlying value without needing the remember/guess the right type.
I converted a couple of call sites to demonstrate usefulness, but
there's likely more of them. I know at least of at least a few in LLDB,
but I don't want to make this a cross-project patch.
ArrayRef now has a new constructor that takes a parameter whose type
has data() and size(). This patch migrates:
ArrayRef<T>(X.data(), X.size()
to:
ArrayRef<T>(X)
When JITLink reports an out-of-range error, the underlying reason could
be hidden from the user if it's due to an excessively large target
addend. Add non-zero target addend to the message for clarity.
These are identified by misc-include-cleaner. I've filtered out those
that break builds. Also, I'm staying away from llvm-config.h,
config.h, and Compiler.h, which likely cause platform- or
compiler-specific build failures.
## Purpose
This patch is one in a series of code-mods that annotate LLVM’s public
interface for export. This patch annotates the `llvm/ExecutionEngine`
library. These annotations currently have no meaningful impact on the
LLVM build; however, they are a prerequisite to support an LLVM Windows
DLL (shared library) build.
## Background
This effort is tracked in #109483. Additional context is provided in
[this
discourse](https://discourse.llvm.org/t/psa-annotating-llvm-public-interface/85307),
and documentation for `LLVM_ABI` and related annotations is found in the
LLVM repo
[here](https://github.com/llvm/llvm-project/blob/main/llvm/docs/InterfaceExportAnnotations.rst).
The bulk of these changes were generated automatically using the
[Interface Definition Scanner (IDS)](https://github.com/compnerd/ids)
tool, followed formatting with `git clang-format`.
The following manual adjustments were also applied after running IDS on
Linux:
- Add `LLVM_ABI_FRIEND` to friend member functions declared with
`LLVM_ABI`
- Add `LLVM_ABI` to a subset of private class methods and fields that
require export
- Add `LLVM_ABI` to a small number of symbols that require export but
are not declared in headers
- Add `LLVM_ABI` to a number of `extern "C"` methods that IDS missed
because they're implicitly exported
## Validation
Local builds and tests to validate cross-platform compatibility. This
included llvm, clang, and lldb on the following configurations:
- Windows with MSVC
- Windows with Clang
- Linux with GCC
- Linux with Clang
- Darwin with Clang
When building on i386, both clang and gcc define a builtin 'i386' macro (see
discussion in https://github.com/llvm/llvm-project/pull/137063). This causes
build errors in the JITLink/i386 backend when attempting to build LLVM on i386.
This commit renames the 'i386' backend (namespaces, APIs and files) to 'x86' to
avoid this issue.
R_386_GOT32 was already handled by lowering to
EdgeKind_i386::RequestGOTAndTransformToDelta32FromGOT. R_386_GOT32X is just an
optionally relaxable version of R_386_GOT32, so we can lower to the same edge
kind.
I've left a TODO to add a relaxable edge kind and update the i386 relaxation
optimization in the future, though I'll probably leave this as an exercise for
any i386 aficionados out there. ;)
This patch replaces:
llvm::copy(Src, std::back_inserter(Dst));
with:
llvm::append_range(Dst, Src);
for breavity.
One side benefit is that llvm::append_range eventually calls
llvm::SmallVector::reserve if Dst is of llvm::SmallVector.
Ptrauth relocations can only be fixed up in the executing process, but noalloc
sections do not have any memory in the executing process. Failure to skip
ptrauth edges results in signing instructions that operate on invalid addresses,
leading to segfaults or data corruption.
Ignoring noalloc sections for ptrauth lowering purposes allows the ptrauth
edges to persist until they reach the applyFixup method, at which point they
raise a useful error and cleanly terminate linking.
Part of ongoing work to make core ORC operations asynchronous.
This only affects the runner utilities, not the AllocationActions themselves.
The AllocationActions will be made asynchronous in a future patch.
Signing a null pointer value can, and usually will, result in some high bits
being set, causing null checks to fail. E.g. in
extern void __attribute__((weak_import)) f(void);
void (*p) = &f;
if f is undefined then p should be null (left unsigned).
This patch updates lowerPointer64AuthEdgesToSigningFunction to check for
Pointer64Authenticated edges to null targets. Where found, these edges are
turned into plain Pointer64 edges (which we know from context will write a null
value to the fixup location), and signing instructions for these locations are
omitted from the signing function.
Compact-unwind encodings are more limited than DWARF frame descriptions. For
functions whose frame layout cannot be described by a compact unwind encoding,
the encoding for the function will specify "use DWARF", and the corresponding
unwind-info record will use the low bits of the encoding to point to the FDE
for the function.
We test this with a frame-pointer=none function, since these frame layouts
always triger a fall-back to DWARF on arm64.
SecondLevelPageOffset should be incremented by SecondLevelPageSize bytes, not
one byte.
Failure to calculate the offset correctly leads to corrupted unwind-info (and
consequently broken exceptions / unwinding) when more than one second level
page is needed. Since JITLink's unwind support only produces
UNWIND_SECOND_LEVEL_REGULAR-style pages this would trigger for any file
containing more than 511 functions with unwind info. The included test-case
contains 1022 functions (sufficient for both the current format and any
future implementation that supports UNWIND_SECOND_LEVEL_COMPRESSED pages).
Thanks to @edoardo on discord for spotting this bug!
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).
Transform Pointer64Authenticated edges into KeepAlive edges, rather than
removing them, in order to preserve symbol dependence information.
The lowerPointer64AuthEdgesToSigningFunction pass is responsible for
transforming Pointer64Authenticated edges to a signing function that can be run
in the executing process to initialize global PAC pointers. Removing the edges
entirely in this pass results in loss of dependence tracking, which can in turn
cause ORC to report PAC pointers as ready before the pointers targets have
completed materialization (resulting in a use-before-finalize error, often
manifesting as access to uninitialized / unprotected memory).
This commit addresses the issue by leaving the edges in the graph and simply
changing their kind to KeepAlive, a no-op for fixup purposes but followed for
dependence tracking purposes.
No testcase: this change just allows edge names to be correctly reported in
debug dumps of LinkGraphs. (Previously Pointer64Authenticated edges were
reported as "<Unrecognized edge kind>").
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.
Linker relaxation is not implemented for jitlink now. But if
relaxation is enabled by clang, R_LARCH_RELAX and
R_LARCH_ALIGN relocations will be emitted.
This commit adapts lld's algorithm to jitlink. Currently, only
relaxing R_LARCH_ALIGN is implemented. Other relaxable
relocs can be implemented in the future.
Without this, interpreting C++ code using clang-repl or running
ir using lli when relaxation is enabled will occur error: `JIT
session error: Unsupported loongarch relocation:102: R_LARCH_ALIGN`.
Similar to 310473c536 but only implement align.
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.
This function can be called on a LinkGraph to get an anonymous symbol pointing
to the start of a mach_header / mach_header_64 block with suitable cputype and
cpusubtype values for the LinkGraph, and with filetype = MachO::MH_OBJECT.
This functionality will be used in the upcoming compact-unwind support patch:
For graphs that do not have a suitable existing header to use (indicated by the
presence of a "__jitlink$libunwind_dso_base" symbol) the compact-unwind support
plugin will create a local header to use as the dso-base to report to
libunwind.
x86_64::GOTTableManager and x86_64::PLTTableManager will now look for existing
GOT and PLT sections and re-use existing entries if they're present.
This will be used for an upcoming MachO patch to enable compact unwind support.
This patch is the x86-64 counterpart 42595bdaefb, which added the same
functionality to the GOT and PLT managers for aarch64.
On platfarms where some relocations for eh-frame sections are implicit (e.g.
MachO/x86-64) EHFrameEdgeFixer is responsible for adding edges for the
implicit relocations.
Adds new convenience methods findDefinedSymbolByName, findExternalSymbolByName
and findAbsoluteSymbolByName to the LinkGraph class. These should be used to
find symbols of the given types by name.
COFFLinkGraphBuilder and MachOPlatform are updated to take advantage of the
new methods.
aarch64::GOTTableManager and aarch64::PLTTableManager will now look for
existing GOT and PLT sections and re-use existing entries if they're present.
This will be used for an upcoming MachO patch to enable compact unwind support.
