This will simplify integration of this code into LLVM -- The
Simple-Packed-Serialization code can be copied near-verbatim, but
WrapperFunctionResult will require more adaptation.
WrapperFunctionResult is a C++ wrapper for __orc_rt_CWrapperFunctionResult
that automatically manages the underlying struct.
The Simple Packed Serialization (SPS) utilities support a simple serialization
scheme for wrapper function argument and result buffers:
Primitive typess (bool, char, int8_t, and uint8_t, int16_t, uint16_t, int32_t,
uint32_t, int64_t, uint64_t) are serialized in little-endian form.
SPSTuples are serialized by serializing each of the tuple members in order
without padding.
SPSSequences are serialized by serializing a sequence length (as a uint64_t)
followed by each of the elements of the sequence in order without padding.
Serialization/deserialization always involves a pair of SPS type tag (a tag
representing the serialized format to use, e.g. uint32_t, or
SPSTuple<bool, SPSString>) and a concrete type to be serialized from or
deserialized to (uint32_t, std::pair<bool, std::string>). Serialization for new
types can be implemented by specializing the SPSSerializationTraits type.
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.
These will be used for error propagation and handling in the ORC runtime.
The implementations of these types are cut-down versions of the error
support in llvm/Support/Error.h. Most advice on llvm::Error and llvm::Expected
(e.g. from the LLVM Programmer's manual) applies equally to __orc_rt::Error
and __orc_rt::Expected. The primary difference is the mechanism for testing
and handling error types: The ORC runtime uses a new 'error_cast' operation
to replace the handleErrors family of functions. See error_cast comments in
error.h.
This is a substitute for std::apply, which we can't use until we move to c++17.
apply_tuple will be used in upcoming the upcoming wrapper-function utils code.
Add unit test infrastructure for the ORC runtime, plus a cut-down
extensible_rtti system and extensible_rtti unit test.
Removes the placeholder.cpp source file.
Differential Revision: https://reviews.llvm.org/D102080
Lang Hames