//===- 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/ExecutionEngine/ExecutionEngine.h"
#include "llvm/ExecutionEngine/JITSymbol.h"
#include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
#include "llvm/ExecutionEngine/SectionMemoryManager.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/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 <memory>
#include <string>
#include <vector>

namespace llvm {
namespace orc {

class KaleidoscopeJIT {
private:
  std::unique_ptr<TargetMachine> TM;
  const DataLayout DL;
  RTDyldObjectLinkingLayer ObjectLayer;
  IRCompileLayer<decltype(ObjectLayer), SimpleCompiler> CompileLayer;

public:
  using ModuleHandle = decltype(CompileLayer)::ModuleSetHandleT;

  KaleidoscopeJIT()
      : TM(EngineBuilder().selectTarget()), DL(TM->createDataLayout()),
        CompileLayer(ObjectLayer, SimpleCompiler(*TM)) {
    llvm::sys::DynamicLibrary::LoadLibraryPermanently(nullptr);
  }

  TargetMachine &getTargetMachine() { return *TM; }

  ModuleHandle addModule(std::unique_ptr<Module> M) {
    // Build our symbol resolver:
    // Lambda 1: Look back into the JIT itself to find symbols that are part of
    //           the same "logical dylib".
    // Lambda 2: Search for external symbols in the host process.
    auto Resolver = createLambdaResolver(
        [&](const std::string &Name) {
          if (auto Sym = CompileLayer.findSymbol(Name, false))
            return Sym;
          return JITSymbol(nullptr);
        },
        [](const std::string &Name) {
          if (auto SymAddr =
                RTDyldMemoryManager::getSymbolAddressInProcess(Name))
            return JITSymbol(SymAddr, JITSymbolFlags::Exported);
          return JITSymbol(nullptr);
        });

    // Build a singleton module set to hold our module.
    std::vector<std::unique_ptr<Module>> Ms;
    Ms.push_back(std::move(M));

    // Add the set to the JIT with the resolver we created above and a newly
    // created SectionMemoryManager.
    return CompileLayer.addModuleSet(std::move(Ms),
                                     make_unique<SectionMemoryManager>(),
                                     std::move(Resolver));
  }

  JITSymbol findSymbol(const std::string Name) {
    std::string MangledName;
    raw_string_ostream MangledNameStream(MangledName);
    Mangler::getNameWithPrefix(MangledNameStream, Name, DL);
    return CompileLayer.findSymbol(MangledNameStream.str(), true);
  }

  void removeModule(ModuleHandle H) {
    CompileLayer.removeModuleSet(H);
  }
};

} // end namespace orc
} // end namespace llvm

#endif // LLVM_EXECUTIONENGINE_ORC_KALEIDOSCOPEJIT_H