Switch the primary implementation of EPC lookupSymbols to be async,
keeping a synchronous wrapper for compatibility. Use the new async
implementation inside EPCDynamicLibrarySearchGenerator to work
working towards a fully async search generator.
Provide an asynchronous lookup API for EPCGenericDylibManager and adopt
that from the SimpleRemoteEPC. This enables an end-to-end async
EPCDynamicLibrarySearchGenerator. Note: currently we keep the current
per-dlhandle lookup model, but a future improvement could do a single
async call for a given lookup operation.
Adds a function to create a LinkGraph of absolute symbols, and a
callback in dynamic library search generators to enable using it to
expose its symbols to the platform/orc runtime. This allows e.g. using
__orc_rt_run_program to run a precompiled function that was found via
dlsym. Ideally we would use this in llvm-jitlink's own search generator,
but it will require more work to align with the Process/Platform
JITDylib split, so not handled here.
As part of this change we need to handle LinkGraphs that only have
absolute symbols.
This migrates the dylib manager lookup and related APIs to replace
ExecutorAddress with ExecutorSymbolDef so that in the future we can
model JITSymbolFlags for these symbols. The current change should be NFC
as we are only setting the Exported symbol flag.
ExecutorAddr was introduced in b8e5f918166 as an eventual replacement for
JITTargetAddress. ExecutorSymbolDef is introduced in this patch as a
replacement for JITEvaluatedSymbol: ExecutorSymbolDef is an (ExecutorAddr,
JITSymbolFlags) pair, where JITEvaluatedSymbol was a (JITTargetAddress,
JITSymbolFlags) pair.
A number of APIs had already migrated from JITTargetAddress to ExecutorAddr,
but many of ORC's internals were still using the older type. This patch aims
to address that.
Some public APIs are affected as well. If you need to migrate your APIs you can
use the following operations:
* ExecutorAddr::toPtr replaces jitTargetAddressToPointer and
jitTargetAddressToFunction.
* ExecutorAddr::fromPtr replace pointerToJITTargetAddress.
* ExecutorAddr(JITTargetAddress) creates an ExecutorAddr value from a
JITTargetAddress.
* ExecutorAddr::getValue() creates a JITTargetAddress value from an
ExecutorAddr.
JITTargetAddress and JITEvaluatedSymbol will remain in JITSymbol.h for now, but
the aim will be to eventually deprecate and remove these types (probably when
MCJIT and RuntimeDyld are deprecated).
Updates tpctypes::DylibHandle to be an ExecutorAddr (rather than a uint64_t),
and SimpleExecutorDylibManager to hold and return raw OS handle values (as
ExecutorAddrs) rather than index values into a map of DynamicLibrary instances.
This will allow clients to use EPCGenericDylibManager in contexts where the
existing DynamicLibrary interface is too limited to be used. (e.g. to look up
JIT symbols in a dylib that was loaded with RTLD_LOCAL).
Wrapper function call and dispatch handler helpers are moved to
ExecutionSession, and existing EPC-based tools are re-written to take an
ExecutionSession argument instead.
Requiring an ExecutorProcessControl instance simplifies existing EPC based
utilities (which only need to take an ES now), and should encourage more
utilities to use the EPC interface. It also simplifies process termination,
since the session can automatically call ExecutorProcessControl::disconnect
(previously this had to be done manually, and carefully ordered with the
rest of JIT tear-down to work correctly).
This is a first step towards consistently using the term 'executor' for the
process that executes JIT'd code. I've opted for 'executor' as the preferred
term over 'target' as target is already heavily overloaded ("the target
machine for the executor" is much clearer than "the target machine for the
target").
