Commit Graph

14 Commits

Author SHA1 Message Date
Fangrui Song 36c7d79dc4 Remove unneeded cl::ZeroOrMore for cl::opt options
Similar to 557efc9a8b.
This commit handles options where cl::ZeroOrMore is more than one line below
cl::opt.
2022-06-04 00:10:42 -07:00
Lang Hames 16dcbb53dc [ORC] Return ExecutorAddrs rather than JITEvaluatedSymbols from LLJIT::lookup.
Clients don't care about linkage, and ExecutorAddr is much more ergonomic.
2022-05-05 13:56:00 -07:00
Lang Hames 118e953b18 Re-apply "[JITLink] Update JITLink to use ExecutorAddr rather... " with fixes.
This re-applies 133f86e954, which was reverted in
c5965a411c while I investigated bot failures.

The original failure contained an arithmetic conversion think-o (on line 419 of
EHFrameSupport.cpp) that could cause failures on 32-bit platforms. The issue
should be fixed in this patch.
2022-01-06 17:22:21 +11:00
Lang Hames c5965a411c Revert "[JITLink] Update JITLink to use ExecutorAddr rather than..."
This reverts commit 133f86e954 while I investigate
the bot failures at https://lab.llvm.org/buildbot#builders/186/builds/3370.
2022-01-06 15:20:21 +11:00
Lang Hames 133f86e954 [JITLink] Update JITLink to use ExecutorAddr rather than JITTargetAddress.
ExecutorAddr is the preferred representation for executor process addresses now.
2022-01-06 13:48:12 +11:00
Lang Hames 962a2479b5 Re-apply e50aea58d5, "Major JITLinkMemoryManager refactor". with fixes.
Adds explicit narrowing casts to JITLinkMemoryManager.cpp.

Honors -slab-address option in llvm-jitlink.cpp, which was accidentally
dropped in the refactor.

This effectively reverts commit 6641d29b70.
2021-10-11 21:39:00 -07:00
Lang Hames 6641d29b70 Revert "[JITLink][ORC] Major JITLinkMemoryManager refactor."
This reverts commit e50aea58d5 while I
investigate bot failures.
2021-10-11 19:23:41 -07:00
Lang Hames e50aea58d5 [JITLink][ORC] Major JITLinkMemoryManager refactor.
This commit substantially refactors the JITLinkMemoryManager API to: (1) add
asynchronous versions of key operations, (2) give memory manager implementations
full control over link graph address layout, (3) enable more efficient tracking
of allocated memory, and (4) support "allocation actions" and finalize-lifetime
memory.

Together these changes provide a more usable API, and enable more powerful and
efficient memory manager implementations.

To support these changes the JITLinkMemoryManager::Allocation inner class has
been split into two new classes: InFlightAllocation, and FinalizedAllocation.
The allocate method returns an InFlightAllocation that tracks memory (both
working and executor memory) prior to finalization. The finalize method returns
a FinalizedAllocation object, and the InFlightAllocation is discarded. Breaking
Allocation into InFlightAllocation and FinalizedAllocation allows
InFlightAllocation subclassses to be written more naturally, and FinalizedAlloc
to be implemented and used efficiently (see (3) below).

In addition to the memory manager changes this commit also introduces a new
MemProt type to represent memory protections (MemProt replaces use of
sys::Memory::ProtectionFlags in JITLink), and a new MemDeallocPolicy type that
can be used to indicate when a section should be deallocated (see (4) below).

Plugin/pass writers who were using sys::Memory::ProtectionFlags will have to
switch to MemProt -- this should be straightworward. Clients with out-of-tree
memory managers will need to update their implementations. Clients using
in-tree memory managers should mostly be able to ignore it.

Major features:

(1) More asynchrony:

The allocate and deallocate methods are now asynchronous by default, with
synchronous convenience wrappers supplied. The asynchronous versions allow
clients (including JITLink) to request and deallocate memory without blocking.

(2) Improved control over graph address layout:

Instead of a SegmentRequestMap, JITLinkMemoryManager::allocate now takes a
reference to the LinkGraph to be allocated. The memory manager is responsible
for calculating the memory requirements for the graph, and laying out the graph
(setting working and executor memory addresses) within the allocated memory.
This gives memory managers full control over JIT'd memory layout. For clients
that don't need or want this degree of control the new "BasicLayout" utility can
be used to get a segment-based view of the graph, similar to the one provided by
SegmentRequestMap. Once segment addresses are assigned the BasicLayout::apply
method can be used to automatically lay out the graph.

(3) Efficient tracking of allocated memory.

The FinalizedAlloc type is a wrapper for an ExecutorAddr and requires only
64-bits to store in the controller. The meaning of the address held by the
FinalizedAlloc is left up to the memory manager implementation, but the
FinalizedAlloc type enforces a requirement that deallocate be called on any
non-default values prior to destruction. The deallocate method takes a
vector<FinalizedAlloc>, allowing for bulk deallocation of many allocations in a
single call.

Memory manager implementations will typically store the address of some
allocation metadata in the executor in the FinalizedAlloc, as holding this
metadata in the executor is often cheaper and may allow for clean deallocation
even in failure cases where the connection with the controller is lost.

(4) Support for "allocation actions" and finalize-lifetime memory.

Allocation actions are pairs (finalize_act, deallocate_act) of JITTargetAddress
triples (fn, arg_buffer_addr, arg_buffer_size), that can be attached to a
finalize request. At finalization time, after memory protections have been
applied, each of the "finalize_act" elements will be called in order (skipping
any elements whose fn value is zero) as

((char*(*)(const char *, size_t))fn)((const char *)arg_buffer_addr,
                                     (size_t)arg_buffer_size);

At deallocation time the deallocate elements will be run in reverse order (again
skipping any elements where fn is zero).

The returned char * should be null to indicate success, or a non-null
heap-allocated string error message to indicate failure.

These actions allow finalization and deallocation to be extended to include
operations like registering and deregistering eh-frames, TLS sections,
initializer and deinitializers, and language metadata sections. Previously these
operations required separate callWrapper invocations. Compared to callWrapper
invocations, actions require no extra IPC/RPC, reducing costs and eliminating
a potential source of errors.

Finalize lifetime memory can be used to support finalize actions: Sections with
finalize lifetime should be destroyed by memory managers immediately after
finalization actions have been run. Finalize memory can be used to support
finalize actions (e.g. with extra-metadata, or synthesized finalize actions)
without incurring permanent memory overhead.
2021-10-11 19:12:42 -07:00
Lang Hames 70c921267e [ORC] Fix some comments in the LLJITWithObjectLinkingLayerPlugin example. 2021-03-12 19:13:42 -08:00
Lang Hames 4e30b20bdb [JITLink][ORC] Make the LinkGraph available to modifyPassConfig.
This makes the target triple, graph name, and full graph content available
when making decisions about how to populate the linker pass pipeline.

Also updates the LLJITWithObjectLinkingLayerPlugin example to show more
API use, including use of the API changes in this patch.
2021-03-12 18:42:51 -08:00
Stefan Gränitz 6edc3fe598 [Orc] Fix OrcV2Examples after D94690
Differential Revision: https://reviews.llvm.org/D94690
2021-01-15 13:45:46 +01:00
Stefan Gränitz cf905274c6 [Orc] Allow LLJITBuilder's CreateObjectLinkingLayer to return errors
It can be useful for an ObjectLinkingLayerCreator to allow callee errors to get propagated to the builder. Specifically, this is the case when the ObjectLayer uses the EHFrameRegistrationPlugin, because it requires a TPCEHFrameRegistrar and instantiation for it may fail (e.g. if the required registration symbols are missing in the target process).

Reviewed By: lhames

Differential Revision: https://reviews.llvm.org/D94690
2021-01-15 12:53:41 +01:00
Lang Hames 0aec49c853 [ORC] Add support for resource tracking/removal (removable code).
This patch introduces new APIs to support resource tracking and removal in Orc.
It is intended as a thread-safe generalization of the removeModule concept from
OrcV1.

Clients can now create ResourceTracker objects (using
JITDylib::createResourceTracker) to track resources for each MaterializationUnit
(code, data, aliases, absolute symbols, etc.) added to the JIT. Every
MaterializationUnit will be associated with a ResourceTracker, and
ResourceTrackers can be re-used for multiple MaterializationUnits. Each JITDylib
has a default ResourceTracker that will be used for MaterializationUnits added
to that JITDylib if no ResourceTracker is explicitly specified.

Two operations can be performed on ResourceTrackers: transferTo and remove. The
transferTo operation transfers tracking of the resources to a different
ResourceTracker object, allowing ResourceTrackers to be merged to reduce
administrative overhead (the source tracker is invalidated in the process). The
remove operation removes all resources associated with a ResourceTracker,
including any symbols defined by MaterializationUnits associated with the
tracker, and also invalidates the tracker. These operations are thread safe, and
should work regardless of the the state of the MaterializationUnits. In the case
of resource transfer any existing resources associated with the source tracker
will be transferred to the destination tracker, and all future resources for
those units will be automatically associated with the destination tracker. In
the case of resource removal all already-allocated resources will be
deallocated, any if any program representations associated with the tracker have
not been compiled yet they will be destroyed. If any program representations are
currently being compiled then they will be prevented from completing: their
MaterializationResponsibility will return errors on any attempt to update the
JIT state.

Clients (usually Layer writers) wishing to track resources can implement the
ResourceManager API to receive notifications when ResourceTrackers are
transferred or removed. The MaterializationResponsibility::withResourceKeyDo
method can be used to create associations between the key for a ResourceTracker
and an allocated resource in a thread-safe way.

RTDyldObjectLinkingLayer and ObjectLinkingLayer are updated to use the
ResourceManager API to enable tracking and removal of memory allocated by the
JIT linker.

The new JITDylib::clear method can be used to trigger removal of every
ResourceTracker associated with the JITDylib (note that this will only
remove resources for the JITDylib, it does not run static destructors).

This patch includes unit tests showing basic usage. A follow-up patch will
update the Kaleidoscope and BuildingAJIT tutorial series to OrcV2 and will
use this API to release code associated with anonymous expressions.
2020-10-18 21:02:54 -07:00
Lang Hames 633ea07200 [Orc] Add basic OrcV2 C bindings and example.
Renames the llvm/examples/LLJITExamples directory to llvm/examples/OrcV2Examples
since it is becoming a home for all OrcV2 examples, not just LLJIT.

See http://llvm.org/PR31103.
2020-03-14 14:41:22 -07:00