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.
