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| //===-- LLJITWithJITLink.cpp - Configure LLJIT to use ObjectLinkingLayer --===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file shows how to switch LLJIT to use ObjectLinkingLayer (which is
// backed by JITLink) rather than RTDyldObjectLinkingLayer (which is backed by
// RuntimeDyld). Using JITLink as the underlying allocator enables use of
// small code model in JIT'd code.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/StringMap.h"
#include "llvm/ExecutionEngine/JITLink/JITLinkMemoryManager.h"
#include "llvm/ExecutionEngine/Orc/LLJIT.h"
#include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h"
#include "llvm/Support/InitLLVM.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/raw_ostream.h"
#include "../ExampleModules.h"
using namespace llvm;
using namespace llvm::orc;
ExitOnError ExitOnErr;
int main(int argc, char *argv[]) {
// Initialize LLVM.
InitLLVM X(argc, argv);
InitializeNativeTarget();
InitializeNativeTargetAsmPrinter();
cl::ParseCommandLineOptions(argc, argv, "HowToUseLLJIT");
ExitOnErr.setBanner(std::string(argv[0]) + ": ");
// Define an in-process JITLink memory manager.
jitlink::InProcessMemoryManager MemMgr;
// Detect the host and set code model to small.
auto JTMB = ExitOnErr(JITTargetMachineBuilder::detectHost());
JTMB.setCodeModel(CodeModel::Small);
// Create an LLJIT instance with an ObjectLinkingLayer as the base layer.
auto J =
ExitOnErr(LLJITBuilder()
.setJITTargetMachineBuilder(std::move(JTMB))
.setObjectLinkingLayerCreator([&](ExecutionSession &ES,
const Triple &TT) {
return std::make_unique<ObjectLinkingLayer>(ES, MemMgr);
})
.create());
auto M = ExitOnErr(parseExampleModule(Add1Example, "add1"));
ExitOnErr(J->addIRModule(std::move(M)));
// Look up the JIT'd function, cast it to a function pointer, then call it.
auto Add1Sym = ExitOnErr(J->lookup("add1"));
int (*Add1)(int) = (int (*)(int))Add1Sym.getAddress();
int Result = Add1(42);
outs() << "add1(42) = " << Result << "\n";
return 0;
}
|