llvm-project/llvm/examples/Kaleidoscope/include/KaleidoscopeJIT.h

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//===- KaleidoscopeJIT.h - A simple JIT for Kaleidoscope --------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Contains a simple JIT definition for use in the kaleidoscope tutorials.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_EXECUTIONENGINE_ORC_KALEIDOSCOPEJIT_H
#define LLVM_EXECUTIONENGINE_ORC_KALEIDOSCOPEJIT_H
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/ExecutionEngine/ExecutionEngine.h"
#include "llvm/ExecutionEngine/JITSymbol.h"
#include "llvm/ExecutionEngine/Orc/CompileUtils.h"
#include "llvm/ExecutionEngine/Orc/IRCompileLayer.h"
#include "llvm/ExecutionEngine/Orc/LambdaResolver.h"
#include "llvm/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.h"
#include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
#include "llvm/ExecutionEngine/SectionMemoryManager.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Mangler.h"
#include "llvm/Support/DynamicLibrary.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include <algorithm>
#include <map>
#include <memory>
#include <string>
#include <vector>
namespace llvm {
namespace orc {
class KaleidoscopeJIT {
public:
using ObjLayerT = RTDyldObjectLinkingLayer;
using CompileLayerT = IRCompileLayer<ObjLayerT, SimpleCompiler>;
KaleidoscopeJIT()
: Resolver(createLegacyLookupResolver(
ES,
[this](const std::string &Name) {
return ObjectLayer.findSymbol(Name, true);
},
[](Error Err) { cantFail(std::move(Err), "lookupFlags failed"); })),
TM(EngineBuilder().selectTarget()), DL(TM->createDataLayout()),
ObjectLayer(ES,
[this](VModuleKey) {
return ObjLayerT::Resources{
std::make_shared<SectionMemoryManager>(), Resolver};
}),
CompileLayer(ObjectLayer, SimpleCompiler(*TM)) {
llvm::sys::DynamicLibrary::LoadLibraryPermanently(nullptr);
}
TargetMachine &getTargetMachine() { return *TM; }
VModuleKey addModule(std::unique_ptr<Module> M) {
auto K = ES.allocateVModule();
cantFail(CompileLayer.addModule(K, std::move(M)));
ModuleKeys.push_back(K);
return K;
}
void removeModule(VModuleKey K) {
ModuleKeys.erase(find(ModuleKeys, K));
cantFail(CompileLayer.removeModule(K));
}
JITSymbol findSymbol(const std::string Name) {
return findMangledSymbol(mangle(Name));
}
private:
std::string mangle(const std::string &Name) {
std::string MangledName;
{
raw_string_ostream MangledNameStream(MangledName);
Mangler::getNameWithPrefix(MangledNameStream, Name, DL);
}
return MangledName;
}
JITSymbol findMangledSymbol(const std::string &Name) {
#ifdef _WIN32
// The symbol lookup of ObjectLinkingLayer uses the SymbolRef::SF_Exported
// flag to decide whether a symbol will be visible or not, when we call
// IRCompileLayer::findSymbolIn with ExportedSymbolsOnly set to true.
//
// But for Windows COFF objects, this flag is currently never set.
// For a potential solution see: https://reviews.llvm.org/rL258665
// For now, we allow non-exported symbols on Windows as a workaround.
const bool ExportedSymbolsOnly = false;
#else
const bool ExportedSymbolsOnly = true;
#endif
// Search modules in reverse order: from last added to first added.
// This is the opposite of the usual search order for dlsym, but makes more
// sense in a REPL where we want to bind to the newest available definition.
for (auto H : make_range(ModuleKeys.rbegin(), ModuleKeys.rend()))
if (auto Sym = CompileLayer.findSymbolIn(H, Name, ExportedSymbolsOnly))
return Sym;
// If we can't find the symbol in the JIT, try looking in the host process.
if (auto SymAddr = RTDyldMemoryManager::getSymbolAddressInProcess(Name))
return JITSymbol(SymAddr, JITSymbolFlags::Exported);
#ifdef _WIN32
// For Windows retry without "_" at beginning, as RTDyldMemoryManager uses
// GetProcAddress and standard libraries like msvcrt.dll use names
// with and without "_" (for example "_itoa" but "sin").
if (Name.length() > 2 && Name[0] == '_')
if (auto SymAddr =
RTDyldMemoryManager::getSymbolAddressInProcess(Name.substr(1)))
return JITSymbol(SymAddr, JITSymbolFlags::Exported);
#endif
return nullptr;
}
ExecutionSession ES;
std::shared_ptr<SymbolResolver> Resolver;
std::unique_ptr<TargetMachine> TM;
const DataLayout DL;
ObjLayerT ObjectLayer;
CompileLayerT CompileLayer;
std::vector<VModuleKey> ModuleKeys;
};
} // end namespace orc
} // end namespace llvm
#endif // LLVM_EXECUTIONENGINE_ORC_KALEIDOSCOPEJIT_H