1 //===--------------- LLJITWithCustomObjectLinkingLayer.cpp ----------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file shows how to switch LLJIT to use a custom object linking layer (we
10 // use ObjectLinkingLayer, which is backed by JITLink, as an example).
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/ADT/StringMap.h"
15 #include "llvm/ExecutionEngine/JITLink/JITLinkMemoryManager.h"
16 #include "llvm/ExecutionEngine/Orc/LLJIT.h"
17 #include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h"
18 #include "llvm/Support/InitLLVM.h"
19 #include "llvm/Support/TargetSelect.h"
20 #include "llvm/Support/raw_ostream.h"
21 
22 #include "../ExampleModules.h"
23 
24 using namespace llvm;
25 using namespace llvm::orc;
26 
27 ExitOnError ExitOnErr;
28 
29 int main(int argc, char *argv[]) {
30   // Initialize LLVM.
31   InitLLVM X(argc, argv);
32 
33   InitializeNativeTarget();
34   InitializeNativeTargetAsmPrinter();
35 
36   cl::ParseCommandLineOptions(argc, argv, "LLJITWithCustomObjectLinkingLayer");
37   ExitOnErr.setBanner(std::string(argv[0]) + ": ");
38 
39   // Detect the host and set code model to small.
40   auto JTMB = ExitOnErr(JITTargetMachineBuilder::detectHost());
41   JTMB.setCodeModel(CodeModel::Small);
42 
43   // Create an LLJIT instance with an ObjectLinkingLayer as the base layer.
44   auto J = ExitOnErr(
45       LLJITBuilder()
46           .setJITTargetMachineBuilder(std::move(JTMB))
47           .setObjectLinkingLayerCreator(
48               [&](ExecutionSession &ES, const Triple &TT) {
49                 return std::make_unique<ObjectLinkingLayer>(
50                     ES, std::make_unique<jitlink::InProcessMemoryManager>());
51               })
52           .create());
53 
54   auto M = ExitOnErr(parseExampleModule(Add1Example, "add1"));
55 
56   ExitOnErr(J->addIRModule(std::move(M)));
57 
58   // Look up the JIT'd function, cast it to a function pointer, then call it.
59   auto Add1Sym = ExitOnErr(J->lookup("add1"));
60   int (*Add1)(int) = (int (*)(int))Add1Sym.getAddress();
61 
62   int Result = Add1(42);
63   outs() << "add1(42) = " << Result << "\n";
64 
65   return 0;
66 }
67