Files
clang-p2996/llvm/lib/ExecutionEngine/Orc/TPCEHFrameRegistrar.cpp
Lang Hames 1d0676b54c [ORC] Break up OrcJIT library, add Orc-RPC based remote TargetProcessControl
implementation.

This patch aims to improve support for out-of-process JITing using OrcV2. It
introduces two new class templates, OrcRPCTargetProcessControlBase and
OrcRPCTPCServer, which together implement the TargetProcessControl API by
forwarding operations to an execution process via an Orc-RPC Endpoint. These
utilities are used to implement out-of-process JITing from llvm-jitlink to
a new llvm-jitlink-executor tool.

This patch also breaks the OrcJIT library into three parts:
  -- OrcTargetProcess: Contains code needed by the JIT execution process.
  -- OrcShared: Contains code needed by the JIT execution and compiler
     processes
  -- OrcJIT: Everything else.

This break-up allows JIT executor processes to link against OrcTargetProcess
and OrcShared only, without having to link in all of OrcJIT. Clients executing
JIT'd code in-process should start linking against OrcTargetProcess as well as
OrcJIT.

In the near future these changes will enable:
  -- Removal of the OrcRemoteTargetClient/OrcRemoteTargetServer class templates
     which provided similar functionality in OrcV1.
  -- Restoration of Chapter 5 of the Building-A-JIT tutorial series, which will
     serve as a simple usage example for these APIs.
  -- Implementation of lazy, cross-target compilation in lli's -jit-kind=orc-lazy
     mode.
2020-11-13 17:05:13 +11:00

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//===------ TPCEHFrameRegistrar.cpp - TPC-based eh-frame registration -----===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/ExecutionEngine/Orc/TPCEHFrameRegistrar.h"
#include "llvm/Support/BinaryStreamWriter.h"
namespace llvm {
namespace orc {
Expected<std::unique_ptr<TPCEHFrameRegistrar>>
TPCEHFrameRegistrar::Create(TargetProcessControl &TPC) {
// FIXME: Proper mangling here -- we really need to decouple linker mangling
// from DataLayout.
// Find the addresses of the registration/deregistration functions in the
// target process.
auto ProcessHandle = TPC.loadDylib(nullptr);
if (!ProcessHandle)
return ProcessHandle.takeError();
std::string RegisterWrapperName, DeregisterWrapperName;
if (TPC.getTargetTriple().isOSBinFormatMachO()) {
RegisterWrapperName += '_';
DeregisterWrapperName += '_';
}
RegisterWrapperName += "llvm_orc_registerEHFrameSectionWrapper";
DeregisterWrapperName += "llvm_orc_deregisterEHFrameSectionWrapper";
SymbolLookupSet RegistrationSymbols;
RegistrationSymbols.add(TPC.intern(RegisterWrapperName));
RegistrationSymbols.add(TPC.intern(DeregisterWrapperName));
auto Result = TPC.lookupSymbols({{*ProcessHandle, RegistrationSymbols}});
if (!Result)
return Result.takeError();
assert(Result->size() == 1 && "Unexpected number of dylibs in result");
assert((*Result)[0].size() == 2 &&
"Unexpected number of addresses in result");
auto RegisterEHFrameWrapperFnAddr = (*Result)[0][0];
auto DeregisterEHFrameWrapperFnAddr = (*Result)[0][1];
return std::make_unique<TPCEHFrameRegistrar>(
TPC, RegisterEHFrameWrapperFnAddr, DeregisterEHFrameWrapperFnAddr);
}
Error TPCEHFrameRegistrar::registerEHFrames(JITTargetAddress EHFrameSectionAddr,
size_t EHFrameSectionSize) {
constexpr size_t ArgBufferSize = sizeof(uint64_t) + sizeof(uint64_t);
uint8_t ArgBuffer[ArgBufferSize];
BinaryStreamWriter ArgWriter(
MutableArrayRef<uint8_t>(ArgBuffer, ArgBufferSize),
support::endianness::big);
cantFail(ArgWriter.writeInteger(static_cast<uint64_t>(EHFrameSectionAddr)));
cantFail(ArgWriter.writeInteger(static_cast<uint64_t>(EHFrameSectionSize)));
return TPC.runWrapper(RegisterEHFrameWrapperFnAddr, ArgBuffer).takeError();
}
Error TPCEHFrameRegistrar::deregisterEHFrames(
JITTargetAddress EHFrameSectionAddr, size_t EHFrameSectionSize) {
constexpr size_t ArgBufferSize = sizeof(uint64_t) + sizeof(uint64_t);
uint8_t ArgBuffer[ArgBufferSize];
BinaryStreamWriter ArgWriter(
MutableArrayRef<uint8_t>(ArgBuffer, ArgBufferSize),
support::endianness::big);
cantFail(ArgWriter.writeInteger(static_cast<uint64_t>(EHFrameSectionAddr)));
cantFail(ArgWriter.writeInteger(static_cast<uint64_t>(EHFrameSectionSize)));
return TPC.runWrapper(DeregisterEHFrameWrapperFnAddr, ArgBuffer).takeError();
}
} // end namespace orc
} // end namespace llvm