In 4 years the ELF debugger support plugin wasn't adapted to other
object formats or debugging approaches. After the renaming NFC in
https://github.com/llvm/llvm-project/pull/168343, this patch tailors the
plugin to ELF and section load-address patching. It allows removal of
abstractions and consolidate processing steps with the newly enabled
AllocActions from https://github.com/llvm/llvm-project/pull/168343.
The key change is to process debug sections in one place in a
post-allocation pass. Since we can handle the endianness of the ELF file
the single `visitSectionLoadAddresses()` visitor function now, we don't
need to track debug objects and sections in template classes anymore. We
keep using the `DebugObject` class and drop `DebugObjectSection`,
`ELFDebugObjectSection<ELFT>` and `ELFDebugObject`.
Furthermore, we now use the allocation's working memory for load-address
fixups directly. We can drop the `WritableMemoryBuffer` from the debug
object and most of the `finalizeWorkingMemory()` step, which saves one
copy of the entire debug object buffer. Inlining `finalizeAsync()` into
the pre-fixup pass simplifies quite some logic.
We still track `RegisteredObjs` here, because we want to free memory
once the corresponding code is freed. There will be a follow-up patch
that turns it into a dealloc action.
In 4 years the plugin wasn't adapted to other object formats. This patch
makes it specific for ELF, which will allow to remove some abstractions
down the line. It also moves the plugin from LLVMOrcJIT into
LLVMOrcDebugging, which didn't exist back then.
The `DebugObjectManagerPlugin` implements debugger support for ELF
platforms with the GDB JIT Interface. It emits a separate debug object
allocation in addition to the LinkGraph's own allocation. This used to
happen in the plugin's `notifyEmitted()` callback, i.e. after the
LinkGraph's allocation was finalized. In the meantime, it had to block
finalization of the corresponding materialization unit to make sure that
the debugger can register the object before the code runs.
This patch switches the plugin to use an allocation action instead. We
can remove the `notifyEmitted()` hook and implement all steps as JITLink
passes.
We just replaced SmallSet<T *, N> with SmallPtrSet<T *, N>, bypassing
the redirection found in SmallSet.h. With that, we no longer need to
include SmallSet.h in many files.
This patch replaces SmallSet<T *, N> with SmallPtrSet<T *, N>. Note
that SmallSet.h "redirects" SmallSet to SmallPtrSet for pointer
element types:
template <typename PointeeType, unsigned N>
class SmallSet<PointeeType*, N> : public SmallPtrSet<PointeeType*, N>
{};
We only have 140 instances that rely on this "redirection", with the
vast majority of them under llvm/. Since relying on the redirection
doesn't improve readability, this patch replaces SmallSet with
SmallPtrSet for pointer element types.
Currently, `DIContext::getLineInfoForAddress` and
`DIContext::getLineInfoForDataAddress` returns empty DILineInfo when the
debug info is missing for the given address. This is not differentiable
with the case when debug info is found for the given address but the
debug info is default value (filename:linenum is <invalid>:0).
This change wraps the return types of `DIContext::getLineInfoForAddress`
and `DIContext::getLineInfoForDataAddress` with `std::optional`.
The debug section map was using MachO section names (with the "__" prefix), but
DWARFContext expects section names with the object format prefix stripped off.
This was preventing DWARFContext from accessing the debug_str section,
resulting in bogus source name strings.
Use SymbolStringPtr for Symbol names in LinkGraph. This reduces string interning
on the boundary between JITLink and ORC, and allows pointer comparisons (rather
than string comparisons) between Symbol names. This should improve the
performance and readability of code that bridges between JITLink and ORC (e.g.
ObjectLinkingLayer and ObjectLinkingLayer::Plugins).
To enable use of SymbolStringPtr a std::shared_ptr<SymbolStringPool> is added to
LinkGraph and threaded through to its construction sites in LLVM and Bolt. All
LinkGraphs that are to have symbol names compared by pointer equality must point
to the same SymbolStringPool instance, which in ORC sessions should be the pool
attached to the ExecutionSession.
---------
Co-authored-by: Lang Hames <lhames@gmail.com>
[ORC] Re-land https://github.com/llvm/llvm-project/pull/81826
This patch adds two plugins: VTuneSupportPlugin.cpp and
JITLoaderVTune.cpp. The testing is done in a manner similar to
llvm-jitlistener. Currently, we only support the old version of Intel
VTune API.
This patch adds two plugins: VTuneSupportPlugin.cpp and
JITLoaderVTune.cpp. The testing is done in a manner similar to
llvm-jitlistener. Currently, we only support the old version of Intel
VTune API.
This pull request is stacked on top of
https://github.com/llvm/llvm-project/pull/81825
This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::{starts,ends}_with in C++20.
I'm planning to deprecate and eventually remove
StringRef::{starts,ends}with.
Allow C-API users to debug their JITed code via the GDB JIT Interface.
This is currently supported on ELF and MachO based platforms. On
other systems `LLVMOrcLLJITEnableDebugSupport()` returns an error.
This patch adds a new C-API header `LLJITUtils.h`, which can host
further advanced JIT features in the future. Using the header requires
linking against LLVMOrcDebugging.
Note that llvm::support::endianness has been renamed to
llvm::endianness while becoming an enum class as opposed to an
enum. This patch replaces support::{big,little,native} with
llvm::endianness::{big,little,native}.
Now that llvm::support::endianness has been renamed to
llvm::endianness, we can use the shorter form. This patch replaces
support::endianness with llvm::endianness.
Now that llvm::support::endianness has been renamed to
llvm::endianness, we can use the shorter form. This patch replaces
support::endianness::{big,little,native} with
llvm::endianness::{big,little,native}.
Without this patch, we pass G.getEndianness() as one of the parameters
to DWARFContext::create. The problem is that G.getEndianness() is of:
enum endianness {big, little, native};
whereas DWARFContext::create is expecting "bool isLittleEndian". That
is, we are relying on an implicit conversion to convert big and little
to false and true, respectively.
When we migrate llvm::support::endianness to std::endian in future, we
can no longer rely on an implicit conversion because std::endian is
declared with "enum class". Even if we could, the conversion would
not be guaranteed to work because, for example, libcxx defines:
enum class endian {
little = 0xDEAD,
big = 0xFACE,
:
where big and little are not boolean values.
This patch fixes the problem by properly converting G.getEndianness()
to a boolean value.
At line 191, `addSymbol` takes the name by reference but does not make
an internal copy to the string, meaning the local
`optional<std::string>` would get freed and leave Orc with a dangling
pointer. Fix this by just using an `optional<StringRef>` instead.
This re-applies db51e572893, which was reverted in 05b1a2cb3e6 due to bot
failures. The DebuggerSupportPlugin now depends on DWARF, so it has been moved
to the new OrcDebugging library (as has the enableDebuggerSupport API).
This patch adds line numbers to perf jitdump records emitted by the
PerfSupportPlugin, by parsing and using a DWARFContext from preserved debug
sections.
To avoid making the OrcJIT library depend on DebugInfoDWARF this patch
introduces a new OrcDebugging library.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D146391
