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//===--------------- LLJITWithCustomObjectLinkingLayer.cpp ----------------===//
//
// 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 a custom object linking layer (we
// use ObjectLinkingLayer, which is backed by JITLink, as an example).
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/StringMap.h"
#include "llvm/ExecutionEngine/JITLink/JITLink.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;
const llvm::StringRef TestMod =
R"(
define i32 @callee() {
entry:
ret i32 7
}
define i32 @entry() {
entry:
%0 = call i32 @callee()
ret i32 %0
}
)";
class MyPlugin : public ObjectLinkingLayer::Plugin {
public:
// The modifyPassConfig callback gives us a chance to inspect the
// MaterializationResponsibility and target triple for the object being
// linked, then add any JITLink passes that we would like to run on the
// link graph. A pass is just a function object that is callable as
// Error(jitlink::LinkGraph&). In this case we will add two passes
// defined as lambdas that call the printLinkerGraph method on our
// plugin: One to run before the linker applies fixups and another to
// run afterwards.
void modifyPassConfig(MaterializationResponsibility &MR, const Triple &TT,
jitlink::PassConfiguration &Config) override {
Config.PostPrunePasses.push_back([this](jitlink::LinkGraph &G) -> Error {
printLinkGraph(G, "Before fixup:");
return Error::success();
});
Config.PostFixupPasses.push_back([this](jitlink::LinkGraph &G) -> Error {
printLinkGraph(G, "After fixup:");
return Error::success();
});
}
void notifyLoaded(MaterializationResponsibility &MR) override {
dbgs() << "Loading object defining " << MR.getSymbols() << "\n";
}
Error notifyEmitted(MaterializationResponsibility &MR) override {
dbgs() << "Emitted object defining " << MR.getSymbols() << "\n";
return Error::success();
}
private:
void printLinkGraph(jitlink::LinkGraph &G, StringRef Title) {
constexpr JITTargetAddress LineWidth = 16;
dbgs() << "--- " << Title << "---\n";
for (auto &S : G.sections()) {
dbgs() << " section: " << S.getName() << "\n";
for (auto *B : S.blocks()) {
dbgs() << " block@" << formatv("{0:x16}", B->getAddress()) << ":\n";
if (B->isZeroFill())
continue;
JITTargetAddress InitAddr = B->getAddress() & ~(LineWidth - 1);
JITTargetAddress StartAddr = B->getAddress();
JITTargetAddress EndAddr = B->getAddress() + B->getSize();
auto *Data = reinterpret_cast<const uint8_t *>(B->getContent().data());
for (JITTargetAddress CurAddr = InitAddr; CurAddr != EndAddr;
++CurAddr) {
if (CurAddr % LineWidth == 0)
dbgs() << " " << formatv("{0:x16}", CurAddr) << ": ";
if (CurAddr < StartAddr)
dbgs() << " ";
else
dbgs() << formatv("{0:x-2}", Data[CurAddr - StartAddr]) << " ";
if (CurAddr % LineWidth == LineWidth - 1)
dbgs() << "\n";
}
if (EndAddr % LineWidth != 0)
dbgs() << "\n";
dbgs() << "\n";
}
}
}
};
int main(int argc, char *argv[]) {
// Initialize LLVM.
InitLLVM X(argc, argv);
InitializeNativeTarget();
InitializeNativeTargetAsmPrinter();
cl::ParseCommandLineOptions(argc, argv, "LLJITWithObjectLinkingLayerPlugin");
ExitOnErr.setBanner(std::string(argv[0]) + ": ");
// 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.
// We attach our plugin in to the newly created ObjectLinkingLayer before
// returning it.
auto J = ExitOnErr(
LLJITBuilder()
.setJITTargetMachineBuilder(std::move(JTMB))
.setObjectLinkingLayerCreator(
[&](ExecutionSession &ES, const Triple &TT) {
// Create ObjectLinkingLayer.
auto ObjLinkingLayer = std::make_unique<ObjectLinkingLayer>(
ES, std::make_unique<jitlink::InProcessMemoryManager>());
// Add an instance of our plugin.
ObjLinkingLayer->addPlugin(std::make_unique<MyPlugin>());
return ObjLinkingLayer;
})
.create());
auto M = ExitOnErr(parseExampleModule(TestMod, "test-module"));
ExitOnErr(J->addIRModule(std::move(M)));
// Look up the JIT'd function, cast it to a function pointer, then call it.
auto EntrySym = ExitOnErr(J->lookup("entry"));
auto *Entry = (int (*)())EntrySym.getAddress();
int Result = Entry();
outs() << "---Result---\n"
<< "entry() = " << Result << "\n";
return 0;
}
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