This is a first step towards allowing programs to pre-link against the ORC
runtime, which would allow us to move some code that is currently in the LLVM
OrcTarget library into the ORC runtime instead.
The C API header has limited utility as-is, but serves as a minimal first step
and provides clients with tools for interacting with wrapper functions.
Reviewed By: beanz
Differential Revision: https://reviews.llvm.org/D127324
* c_api_tests was failing to build after the API change to
__orc_rt_CWrapperFunctionResultAllocate
* wrapper_function_utils_test was causing an assertion failure, because
it was creating a result for `void(void)` with Size = 0, but seeing an
uninitialized pointer, which it considered to be an out-of-bound
error.
I noticed locally that making modifications to c_api.h is not causing
these unit tests to be rebuilt, which may be how the bug slipped in in
the first place.
Differential Revision: https://reviews.llvm.org/D108649
OrcRTCWrapperFunctionResult is a C struct that can be used to return serialized
results from "wrapper functions" -- functions that deserialize an argument
buffer, call through to an actual implementation function, then serialize and
return the result of that function. Wrapper functions allow calls between ORC
and the ORC Runtime to be written using a single signature,
WrapperFunctionResult(const char *ArgData, size_t ArgSize), and without coupling
either side to a particular transport mechanism (in-memory, TCP, IPC, ... the
actual mechanism will be determined by the TargetProcessControl implementation).
OrcRTCWrapperFunctionResult is designed to allow small serialized buffers to
be returned by value, with larger serialized results stored on the heap. They
also provide an error state to report failures in serialization/deserialization.