/******************************************************************************
 * Copyright (C) 2015-2020 Dibyendu Majumdar
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 ******************************************************************************/
#include <ravi_llvmcodegen.h>
#include <ravijit.h>
// Important to include the C++ header files (ravi_llvmcodegen.h) before following
// (ravi_jitshared.h) as the Lua headers define macros that mess with C++ headers
#include <ravi_jitshared.h>

/*
 * Implementation Notes:
 * Each Lua function is compiled into an LLVM Module/Function
 * This strategy allows functions to be garbage collected as normal by Lua
 * See issue #78 for changes to this (wip)
 */

namespace ravi {

// This is just to avoid initializing LLVM repeatedly -
// see below
static std::atomic_int init;

static const char *errortext[] = {"integer expected",
                                  "number expected",
                                  "integer[] expected",
                                  "number[] expected",
                                  "table expected",
                                  "upvalue of integer type, cannot be set to non integer value",
                                  "upvalue of number type, cannot be set to non number value",
                                  "upvalue of integer[] type, cannot be set to non integer[] value",
                                  "upvalue of number[] type, cannot be set to non number[] value",
                                  "upvalue of table type, cannot be set to non table value",
                                  "for llimit must be a number",
                                  "for step must be a number",
                                  "for initial value must be a number",
                                  "array index is out of bounds",
                                  "string expected",
                                  "closure expected",
                                  "type mismatch: wrong userdata type",
                                  NULL};

static void raise_error(lua_State *L, int errorcode) {
  assert(errorcode >= 0 && errorcode <= Error_type_mismatch);
  luaG_runerror(L, errortext[errorcode]);
}

static struct {
  const char *name;
  void *address;
} global_syms[] = {{"lua_absindex", reinterpret_cast<void *>(lua_absindex)},
                   {"lua_gettop", reinterpret_cast<void *>(lua_gettop)},
                   {"lua_settop", reinterpret_cast<void *>(lua_settop)},
                   {"lua_pushvalue", reinterpret_cast<void *>(lua_pushvalue)},
                   {"lua_rotate", reinterpret_cast<void *>(lua_rotate)},
                   {"lua_copy", reinterpret_cast<void *>(lua_copy)},
                   {"lua_checkstack", reinterpret_cast<void *>(lua_checkstack)},
                   {"lua_xmove", reinterpret_cast<void *>(lua_xmove)},
                   {"lua_isnumber", reinterpret_cast<void *>(lua_isnumber)},
                   {"lua_isstring", reinterpret_cast<void *>(lua_isstring)},
                   {"lua_iscfunction", reinterpret_cast<void *>(lua_iscfunction)},
                   {"lua_isinteger", reinterpret_cast<void *>(lua_isinteger)},
                   {"lua_isuserdata", reinterpret_cast<void *>(lua_isuserdata)},
                   {"lua_type", reinterpret_cast<void *>(lua_type)},
                   {"lua_typename", reinterpret_cast<void *>(lua_typename)},
                   {"lua_tonumberx", reinterpret_cast<void *>(lua_tonumberx)},
                   {"lua_tointegerx", reinterpret_cast<void *>(lua_tointegerx)},
                   {"lua_toboolean", reinterpret_cast<void *>(lua_toboolean)},
                   {"lua_tolstring", reinterpret_cast<void *>(lua_tolstring)},
                   {"lua_rawlen", reinterpret_cast<void *>(lua_rawlen)},
                   {"lua_tocfunction", reinterpret_cast<void *>(lua_tocfunction)},
                   {"lua_touserdata", reinterpret_cast<void *>(lua_touserdata)},
                   {"lua_tothread", reinterpret_cast<void *>(lua_tothread)},
                   {"lua_topointer", reinterpret_cast<void *>(lua_topointer)},
                   {"lua_arith", reinterpret_cast<void *>(lua_arith)},
                   {"lua_rawequal", reinterpret_cast<void *>(lua_rawequal)},
                   {"lua_compare", reinterpret_cast<void *>(lua_compare)},
                   {"lua_pushnil", reinterpret_cast<void *>(lua_pushnil)},
                   {"lua_pushnumber", reinterpret_cast<void *>(lua_pushnumber)},
                   {"lua_pushinteger", reinterpret_cast<void *>(lua_pushinteger)},
                   {"lua_pushlstring", reinterpret_cast<void *>(lua_pushlstring)},
                   {"lua_pushstring", reinterpret_cast<void *>(lua_pushstring)},
                   {"lua_pushvfstring", reinterpret_cast<void *>(lua_pushvfstring)},
                   {"lua_pushfstring", reinterpret_cast<void *>(lua_pushfstring)},
                   {"lua_pushcclosure", reinterpret_cast<void *>(lua_pushcclosure)},
                   {"lua_pushboolean", reinterpret_cast<void *>(lua_pushboolean)},
                   {"lua_pushlightuserdata", reinterpret_cast<void *>(lua_pushlightuserdata)},
                   {"lua_pushthread", reinterpret_cast<void *>(lua_pushthread)},
                   {"lua_getglobal", reinterpret_cast<void *>(lua_getglobal)},
                   {"lua_gettable", reinterpret_cast<void *>(lua_gettable)},
                   {"lua_getfield", reinterpret_cast<void *>(lua_getfield)},
                   {"lua_geti", reinterpret_cast<void *>(lua_geti)},
                   {"lua_rawget", reinterpret_cast<void *>(lua_rawget)},
                   {"lua_rawgeti", reinterpret_cast<void *>(lua_rawgeti)},
                   {"lua_rawgetp", reinterpret_cast<void *>(lua_rawgetp)},
                   {"lua_createtable", reinterpret_cast<void *>(lua_createtable)},
                   {"lua_newuserdata", reinterpret_cast<void *>(lua_newuserdata)},
                   {"lua_getmetatable", reinterpret_cast<void *>(lua_getmetatable)},
                   {"lua_getuservalue", reinterpret_cast<void *>(lua_getuservalue)},
                   {"lua_setglobal", reinterpret_cast<void *>(lua_setglobal)},
                   {"lua_settable", reinterpret_cast<void *>(lua_settable)},
                   {"lua_setfield", reinterpret_cast<void *>(lua_setfield)},
                   {"lua_seti", reinterpret_cast<void *>(lua_seti)},
                   {"lua_rawset", reinterpret_cast<void *>(lua_rawset)},
                   {"lua_rawseti", reinterpret_cast<void *>(lua_rawseti)},
                   {"lua_rawsetp", reinterpret_cast<void *>(lua_rawsetp)},
                   {"lua_setmetatable", reinterpret_cast<void *>(lua_setmetatable)},
                   {"lua_setuservalue", reinterpret_cast<void *>(lua_setuservalue)},
                   {"lua_gc", reinterpret_cast<void *>(lua_gc)},
                   {"lua_error", reinterpret_cast<void *>(lua_error)},
                   {"lua_next", reinterpret_cast<void *>(lua_next)},
                   {"lua_concat", reinterpret_cast<void *>(lua_concat)},
                   {"lua_len", reinterpret_cast<void *>(lua_len)},
                   {"lua_stringtonumber", reinterpret_cast<void *>(lua_stringtonumber)},
                   {"luaF_close", reinterpret_cast<void *>(luaF_close)},
                   {"raise_error", reinterpret_cast<void *>(raise_error)},
                   {"luaV_tonumber_", reinterpret_cast<void *>(luaV_tonumber_)},
                   {"luaV_tointeger", reinterpret_cast<void *>(luaV_tointeger)},
                   {"luaD_poscall", reinterpret_cast<void *>(luaD_poscall)},
                   {"luaV_equalobj", reinterpret_cast<void *>(luaV_equalobj)},
                   {"luaV_lessthan", reinterpret_cast<void *>(luaV_lessthan)},
                   {"luaV_lessequal", reinterpret_cast<void *>(luaV_lessequal)},
                   {"luaV_execute", reinterpret_cast<void *>(luaV_execute)},
                   {"luaV_gettable", reinterpret_cast<void *>(luaV_gettable)},
                   {"luaV_settable", reinterpret_cast<void *>(luaV_settable)},
                   {"luaD_precall", reinterpret_cast<void *>(luaD_precall)},
                   {"raviV_op_newtable", reinterpret_cast<void *>(raviV_op_newtable)},
                   {"luaO_arith", reinterpret_cast<void *>(luaO_arith)},
                   {"raviV_op_newarrayint", reinterpret_cast<void *>(raviV_op_newarrayint)},
                   {"raviV_op_newarrayfloat", reinterpret_cast<void *>(raviV_op_newarrayfloat)},
                   {"raviV_op_setlist", reinterpret_cast<void *>(raviV_op_setlist)},
                   {"raviV_op_concat", reinterpret_cast<void *>(raviV_op_concat)},
                   {"raviV_op_closure", reinterpret_cast<void *>(raviV_op_closure)},
                   {"raviV_op_vararg", reinterpret_cast<void *>(raviV_op_vararg)},
                   {"luaV_objlen", reinterpret_cast<void *>(luaV_objlen)},
                   {"luaV_forlimit", reinterpret_cast<void *>(luaV_forlimit)},
                   {"raviV_op_setupval", reinterpret_cast<void *>(raviV_op_setupval)},
                   {"raviV_op_setupvali", reinterpret_cast<void *>(raviV_op_setupvali)},
                   {"raviV_op_setupvalf", reinterpret_cast<void *>(raviV_op_setupvalf)},
                   {"raviV_op_setupvalai", reinterpret_cast<void *>(raviV_op_setupvalai)},
                   {"raviV_op_setupvalaf", reinterpret_cast<void *>(raviV_op_setupvalaf)},
                   {"raviV_op_setupvalt", reinterpret_cast<void *>(raviV_op_setupvalt)},
                   {"luaD_call", reinterpret_cast<void *>(luaD_call)},
                   {"raviH_set_int", reinterpret_cast<void *>(raviH_set_int)},
                   {"raviH_set_float", reinterpret_cast<void *>(raviH_set_float)},
                   {"raviV_check_usertype", reinterpret_cast<void *>(raviV_check_usertype)},
                   {"luaT_trybinTM", reinterpret_cast<void *>(luaT_trybinTM)},
                   {"raviV_gettable_sskey", reinterpret_cast<void *>(raviV_gettable_sskey)},
                   {"raviV_settable_sskey", reinterpret_cast<void *>(raviV_settable_sskey)},
                   {"raviV_gettable_i", reinterpret_cast<void *>(raviV_gettable_i)},
                   {"raviV_settable_i", reinterpret_cast<void *>(raviV_settable_i)},
                   {"printf", reinterpret_cast<void *>(printf)},
                   {"puts", reinterpret_cast<void *>(puts)},
                   {nullptr, nullptr}};

// Construct the JIT compiler state
// The JIT compiler state will be attached to the
// lua_State - all compilation activity happens
// in the context of the JIT State
RaviJITState::RaviJITState()
    : auto_(false),
      enabled_(true),
      opt_level_(2),
      size_level_(0),
      verbosity_(0),
      tracehook_enabled_(false),
      validation_(false),
      use_dmrc_(false),
      gcstep_(300),
      min_code_size_(150),
      min_exec_count_(50),
      allocated_modules_(0),
      compiling_(false) {
  // LLVM needs to be initialized else
  // ExecutionEngine cannot be created
  // This needs to be an atomic check although LLVM docs
  // say that it is okay to call these functions more than once
  if (init == 0) {
    llvm::InitializeNativeTarget();
    llvm::InitializeNativeTargetAsmPrinter();
    llvm::InitializeNativeTargetAsmParser();
    // TODO see email trail on resolving symbols in process
    llvm::sys::DynamicLibrary::LoadLibraryPermanently(nullptr);
    init++;
  }
  triple_ = llvm::sys::getProcessTriple();
  if (::getenv("RAVI_USE_DMRC_LLVM"))
    use_dmrc_ = true;

#if USE_ORCv2_JIT

  auto JTMB = llvm::cantFail(llvm::orc::JITTargetMachineBuilder::detectHost());
  JTMB.setCodeGenOptLevel(llvm::CodeGenOpt::Default);
  auto dataLayout = llvm::cantFail(JTMB.getDefaultDataLayoutForTarget());
  TM = llvm::cantFail(JTMB.createTargetMachine());
  ES = llvm::make_unique<llvm::orc::ExecutionSession>();
  ObjectLayer = llvm::make_unique<llvm::orc::RTDyldObjectLinkingLayer>(
      *ES, []() { return llvm::make_unique<llvm::SectionMemoryManager>(); });
  CompileLayer = llvm::make_unique<llvm::orc::IRCompileLayer>(*ES, *ObjectLayer, llvm::orc::SimpleCompiler(*TM));
  OptimizeLayer = llvm::make_unique<llvm::orc::IRTransformLayer>(
      *ES, *CompileLayer, [this](llvm::orc::ThreadSafeModule TSM, const llvm::orc::MaterializationResponsibility &R) {
        return this->optimizeModule(std::move(TSM), R);
      });
  DL = llvm::make_unique<llvm::DataLayout>(std::move(dataLayout));
  Mangle = llvm::make_unique<llvm::orc::MangleAndInterner>(*ES, *this->DL);
  Ctx = llvm::make_unique<llvm::orc::ThreadSafeContext>(llvm::make_unique<llvm::LLVMContext>());
#if LLVM_VERSION_MAJOR >= 9
  ES->getMainJITDylib().setGenerator(llvm::cantFail(llvm::orc::DynamicLibrarySearchGenerator::GetForCurrentProcess(DL->getGlobalPrefix())));
#else
  ES->getMainJITDylib().setGenerator(llvm::cantFail(llvm::orc::DynamicLibrarySearchGenerator::GetForCurrentProcess(*DL)));
#endif
  types_ = llvm::make_unique<LuaLLVMTypes>(*Ctx->getContext());

#else

#if defined(_WIN32) && (!defined(_WIN64) || LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR < 7)
  // On Windows we get compilation error saying incompatible object format
  // Reading posts on mailing lists I found that the issue is that COEFF
  // format is not supported and therefore we need to set -elf as the object
  // format; LLVM 3.7 onwards COEFF is supported
  triple_ += "-elf";
#endif
  context_ = std::unique_ptr<llvm::LLVMContext>(new llvm::LLVMContext());

#if USE_ORC_JIT
  auto target = llvm::EngineBuilder().selectTarget();
  TM = std::unique_ptr<llvm::TargetMachine>(target);
  TM->setO0WantsFastISel(true);  // enable FastISel when -O0 is used
  DL = std::unique_ptr<llvm::DataLayout>(new llvm::DataLayout(TM->createDataLayout()));

#if LLVM_VERSION_MAJOR >= 8
  StringPool = std::make_shared<llvm::orc::SymbolStringPool>();
  ES = std::unique_ptr<llvm::orc::ExecutionSession>(new llvm::orc::ExecutionSession(StringPool));
  ObjectLayer = std::unique_ptr<ObjectLayerT>(new ObjectLayerT(*ES, [this](llvm::orc::VModuleKey K) {
    return ObjectLayerT::Resources{std::make_shared<llvm::SectionMemoryManager>(), Resolvers[K]};
  }));
#else
  ObjectLayer =
      std::unique_ptr<ObjectLayerT>(new ObjectLayerT([]() { return std::make_shared<llvm::SectionMemoryManager>(); }));
#endif

  CompileLayer = std::unique_ptr<CompileLayerT>(new CompileLayerT(*ObjectLayer, llvm::orc::SimpleCompiler(*TM)));

#if LLVM_VERSION_MAJOR >= 8
  OptimizeLayer = std::unique_ptr<OptimizerLayerT>(new OptimizerLayerT(
      *CompileLayer, [this](std::unique_ptr<llvm::Module> M) { return optimizeModule(std::move(M)); }));
  CompileCallbackManager = cantFail(llvm::orc::createLocalCompileCallbackManager(TM->getTargetTriple(), *ES, 0));
  CompileOnDemandLayer = std::unique_ptr<CODLayerT>(new CODLayerT(
      *ES, *OptimizeLayer, [&](llvm::orc::VModuleKey K) { return Resolvers[K]; },
      [&](llvm::orc::VModuleKey K, std::shared_ptr<llvm::orc::SymbolResolver> R) { Resolvers[K] = std::move(R); },
      [](llvm::Function &F) { return std::set<llvm::Function *>({&F}); }, *CompileCallbackManager,
      llvm::orc::createLocalIndirectStubsManagerBuilder(TM->getTargetTriple())));
#else
  OptimizeLayer = std::unique_ptr<OptimizerLayerT>(new OptimizerLayerT(
      *CompileLayer, [this](std::shared_ptr<llvm::Module> M) { return optimizeModule(std::move(M)); }));
#endif

#endif

  types_ = std::unique_ptr<LuaLLVMTypes>(new LuaLLVMTypes(*context_));

#endif  // USE_ORCv2_JIT

  // Register global symbols
#if USE_ORCv2_JIT
  auto &JD = ES->getMainJITDylib();
  llvm::orc::MangleAndInterner mangle(*ES, *this->DL);
  llvm::orc::SymbolMap Symbols;
  for (int i = 0; global_syms[i].name != nullptr; i++) {
    Symbols.insert({mangle(global_syms[i].name),
                    llvm::JITEvaluatedSymbol(llvm::pointerToJITTargetAddress(global_syms[i].address),
                                             llvm::JITSymbolFlags(llvm::JITSymbolFlags::FlagNames::Absolute))});
  }
  llvm::cantFail(JD.define(llvm::orc::absoluteSymbols(Symbols)), "Failed to install extern symbols");
#else
  for (int i = 0; global_syms[i].name != nullptr; i++) {
    llvm::sys::DynamicLibrary::AddSymbol(global_syms[i].name, global_syms[i].address);
  }
#endif
}

// Destroy the JIT state freeing up any
// functions that were compiled
RaviJITState::~RaviJITState() { assert(allocated_modules_ == 0); }

#if USE_ORC_JIT || USE_ORCv2_JIT
#if USE_ORCv2_JIT
llvm::Expected<llvm::orc::ThreadSafeModule> RaviJITState::optimizeModule(
    llvm::orc::ThreadSafeModule TSM, const llvm::orc::MaterializationResponsibility &R) {
#else
#if LLVM_VERSION_MAJOR >= 8
std::unique_ptr<llvm::Module> RaviJITState::optimizeModule(std::unique_ptr<llvm::Module> M) {
#else
std::shared_ptr<llvm::Module> RaviJITState::optimizeModule(std::shared_ptr<llvm::Module> M) {
#endif
#endif
  using llvm::legacy::FunctionPassManager;
  using llvm::legacy::PassManager;

#if USE_ORCv2_JIT
  auto M = TSM.getModule();
#endif
  if (get_verbosity() >= 1)
    M->print(llvm::errs(), nullptr, false, true);
  if (get_verbosity() >= 3)
    TM->Options.PrintMachineCode = 1;
  else
    TM->Options.PrintMachineCode = 0;
  if (get_optlevel() == 0)
    TM->Options.EnableFastISel = 1;
  else
    TM->Options.EnableFastISel = 0;

  // We use the PassManagerBuilder to setup optimization
  // passes - the PassManagerBuilder allows easy configuration of
  // typical C/C++ passes corresponding to O0, O1, O2, and O3 compiler options
  // If dumpAsm is true then the generated assembly code will be
  // dumped to stderr

  llvm::PassManagerBuilder pmb;

  pmb.OptLevel = get_optlevel();
  pmb.SizeLevel = get_sizelevel();
  {
    // Create a function pass manager for this engine
    auto FPM = llvm::make_unique<FunctionPassManager>(&*M);
    pmb.populateFunctionPassManager(*FPM);
    FPM->doInitialization();
    // Run the optimizations over all functions in the module being added to
    // the JIT.
    // llvm::dbgs() << "Before optimization:\n" << *M << "-->\n";
    for (auto &F : *M)
      FPM->run(F);
  }
  std::string codestr;
  {
    llvm::raw_string_ostream ostream(codestr);
    llvm::buffer_ostream formatted_stream(ostream);

    std::unique_ptr<PassManager> MPM(new PassManager());
    pmb.populateModulePassManager(*MPM);

    for (int i = 0; get_verbosity() == 2 && i < 1; i++) {
      if (!TM) {
        llvm::errs() << "unable to dump assembly\n";
        break;
      }
      if (TM->addPassesToEmitFile(*MPM, formatted_stream,
#if LLVM_VERSION_MAJOR >= 7
                                  nullptr,  // DWO output file
#endif
                                  llvm::TargetMachine::CGFT_AssemblyFile)) {
        llvm::errs() << "unable to add passes for generating assemblyfile\n";
        break;
      }
    }
    MPM->run(*M);
    // llvm::dbgs() << "After optimization:\n" << *M << "-->\n";
  }
  if (get_verbosity() == 2 && codestr.length() > 0)
    llvm::errs() << codestr << "\n";

#if USE_ORCv2_JIT
  return TSM;
#else
  return M;
#endif
}

#endif

void RaviJITState::addGlobalSymbol(const std::string &name, void *address) {
  llvm::sys::DynamicLibrary::AddSymbol(name, address);
}

#if USE_ORCv2_JIT
llvm::Error RaviJITState::addModule(std::unique_ptr<llvm::Module> M) {
  return OptimizeLayer->add(ES->getMainJITDylib(), llvm::orc::ThreadSafeModule(std::move(M), *Ctx));
}
#elif USE_ORC_JIT
RaviJITState::ModuleHandle RaviJITState::addModule(std::unique_ptr<llvm::Module> M) {
#if LLVM_VERSION_MAJOR >= 8
  // Create a new VModuleKey.
  llvm::orc::VModuleKey K = ES->allocateVModule();
  // Build a resolver and associate it with the new key.
  Resolvers[K] =
      createLegacyLookupResolver(*ES,
                                 [this](const std::string &Name) -> llvm::JITSymbol {
                                   if (auto Sym = CompileLayer->findSymbol(Name, false))
                                     return Sym;
                                   else if (auto Err = Sym.takeError())
                                     return std::move(Err);
                                   if (auto SymAddr = llvm::RTDyldMemoryManager::getSymbolAddressInProcess(Name))
                                     return llvm::JITSymbol(SymAddr, llvm::JITSymbolFlags::Exported);
                                   return nullptr;
                                 },
                                 [](llvm::Error Err) { cantFail(std::move(Err), "lookupFlags failed"); });
  // Add the module to the JIT with the new key.
  llvm::cantFail(CompileOnDemandLayer->addModule(K, std::move(M)));
  return K;
#else
  // 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 = llvm::orc::createLambdaResolver(
      [&](const std::string &Name) {
        if (auto Sym = OptimizeLayer->findSymbol(Name, false))
          return Sym;
        return llvm::JITSymbol(nullptr);
      },
      [](const std::string &Name) {
        if (auto SymAddr = llvm::RTDyldMemoryManager::getSymbolAddressInProcess(Name))
          return llvm::JITSymbol(SymAddr, llvm::JITSymbolFlags::Exported);
        return llvm::JITSymbol(nullptr);
      });

  // Add the set to the JIT with the resolver we created above and a newly
  // created SectionMemoryManager.
  return llvm::cantFail(OptimizeLayer->addModule(std::move(M), std::move(Resolver)));
#endif
}

llvm::JITSymbol RaviJITState::findSymbol(const std::string &Name) {
  std::string MangledName;
  llvm::raw_string_ostream MangledNameStream(MangledName);
  llvm::Mangler::getNameWithPrefix(MangledNameStream, Name, *DL);
#if LLVM_VERSION_MAJOR >= 8
  return CompileOnDemandLayer->findSymbol(MangledNameStream.str(), false);
#else
  // Note that the LLVM tutorial uses true below but that appears to
  // cause a failure in lookup
  return OptimizeLayer->findSymbol(MangledNameStream.str(), false);
#endif
}

void RaviJITState::removeModule(ModuleHandle H) {
#if LLVM_VERSION_MAJOR >= 8
  if (H) {
    llvm::cantFail(CompileOnDemandLayer->removeModule(H));
  }
#else
  llvm::cantFail(OptimizeLayer->removeModule(H));
#endif
}
#endif

void RaviJITState::dump() { types_->dump(); }

static std::atomic_int module_id;

RaviJITModule::RaviJITModule(RaviJITState *owner)
    : owner_(owner)
#if !USE_ORC_JIT
      ,
      module_(nullptr),
      engine_(nullptr)
#elif !USE_ORCv2_JIT
      ,
      module_handle_(0)
#endif
{
  int myid = module_id++;
  char buf[40];
  snprintf(buf, sizeof buf, "ravi_module_%d", myid);
  std::string moduleName(buf);
#if USE_ORCv2_JIT
  module_ = std::unique_ptr<llvm::Module>(new llvm::Module(moduleName, owner->context()));
  module_->setDataLayout(owner_->getDataLayout());
#elif USE_ORC_JIT
  module_ = std::unique_ptr<llvm::Module>(new llvm::Module(moduleName, owner->context()));
  module_->setDataLayout(owner_->getTargetMachine().createDataLayout());
#else
  module_ = new llvm::Module(moduleName, owner->context());
#endif
  if (myid == 0) {
    // Extra validation to check that the LLVM sizes match Lua sizes
    auto layout = std::unique_ptr<llvm::DataLayout>(new llvm::DataLayout(module()));
    // auto valueSize = layout->getTypeAllocSize(owner->types()->ValueT);
    // auto valueSizeOf = sizeof(Value);
    // auto TvalueSize = layout->getTypeAllocSize(owner->types()->TValueT);
    // auto TvalueSizeOf = sizeof(TValue);
    // printf("Value %d %d Tvalue %d %d\n", (int)valueSize, (int)valueSizeOf,
    // (int)TvalueSize, (int)TvalueSizeOf);
    assert(sizeof(Value) == layout->getTypeAllocSize(owner->types()->ValueT));
    assert(sizeof(TValue) == layout->getTypeAllocSize(owner->types()->TValueT));
    assert(sizeof(UTString) == layout->getTypeAllocSize(owner->types()->TStringT));
    assert(sizeof(Udata) == layout->getTypeAllocSize(owner->types()->UdataT));
    assert(sizeof(CallInfo) == layout->getTypeAllocSize(owner->types()->CallInfoT));
    assert(sizeof(lua_State) == layout->getTypeAllocSize(owner->types()->lua_StateT));
  }
#if !USE_ORC_JIT
#if defined(_WIN32) && (!defined(_WIN64) || LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR < 7)
  // On Windows we get error saying incompatible object format
  // Reading posts on mailing lists I found that the issue is that COEFF
  // format is not supported and therefore we need to set
  // -elf as the object format; LLVM 3.7 onwards COEFF is supported
  module_->setTargetTriple(owner->triple());
#endif
#if LLVM_VERSION_MAJOR > 3 || LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR > 5
  // LLVM 3.6.0 change
  std::unique_ptr<llvm::Module> module(module_);
  llvm::EngineBuilder builder(std::move(module));
#else
  llvm::EngineBuilder builder(module_);
  builder.setUseMCJIT(true);
#endif
  builder.setEngineKind(llvm::EngineKind::JIT);
  std::string errStr;
  builder.setErrorStr(&errStr);
  engine_ = builder.create();
  if (!engine_) {
    fprintf(stderr, "FATAL ERROR: could not create ExecutionEngine: %s\n", errStr.c_str());
    abort();
    return;
  }
#endif
  owner->incr_allocated_modules();
}

RaviJITModule::~RaviJITModule() {
#if !USE_ORC_JIT
  if (engine_)
    delete engine_;
  else if (module_)
    // if engine was created then we don't need to delete the
    // module as it would have been deleted by the engine
    delete module_;
#elif !USE_ORCv2_JIT
  owner()->removeModule(module_handle_);
#endif
  owner_->decr_allocated_modules();
#if 1
  // fprintf(stderr, "module destroyed\n");
#endif
}

int RaviJITModule::addFunction(RaviJITFunction *f) {
  int id = functions_.size();
  functions_.push_back(f);
  return id;
}

void RaviJITModule::removeFunction(RaviJITFunction *f) {
  lua_assert(functions_[f->getId()] == f);
  functions_[f->getId()] = nullptr;
}

RaviJITFunction::RaviJITFunction(lua_CFunction *p, const std::shared_ptr<RaviJITModule> &module,
                                 llvm::FunctionType *type, llvm::GlobalValue::LinkageTypes linkage,
                                 const std::string &name)
    : module_(module), name_(name), function_(nullptr), ptr_(nullptr), func_ptrptr_(p) {
  auto M = module_->module();
  lua_assert(M);
  function_ = llvm::Function::Create(type, linkage, name, M);
  id_ = module_->addFunction(this);
}

RaviJITFunction::RaviJITFunction(lua_CFunction *p, const std::shared_ptr<RaviJITModule> &module,
                                 const std::string &name)
    : module_(module), name_(name), ptr_(nullptr), func_ptrptr_(p) {
  auto M = module_->module();
  lua_assert(M);
  function_ = M->getFunction(name);
  id_ = module_->addFunction(this);
}

RaviJITFunction::~RaviJITFunction() {
  // Remove this function from parent
  // fprintf(stderr, "function destroyed\n");
  module_->removeFunction(this);
}

// This is noop when ORC api is enabled
// Retained for backward compatibility
void RaviJITModule::runpasses(bool dumpAsm) {
#if !USE_ORC_JIT
  if (!module_)
    return;

#if LLVM_VERSION_MAJOR > 3 || LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR >= 7
  using llvm::legacy::FunctionPassManager;
  using llvm::legacy::PassManager;
#else
  using llvm::FunctionPassManager;
  using llvm::PassManager;
#endif

  // We use the PassManagerBuilder to setup optimization
  // passes - the PassManagerBuilder allows easy configuration of
  // typical C/C++ passes corresponding to O0, O1, O2, and O3 compiler options
  // If dumpAsm is true then the generated assembly code will be
  // dumped to stderr

  llvm::PassManagerBuilder pmb;
  pmb.OptLevel = owner_->get_optlevel();
  pmb.SizeLevel = owner_->get_sizelevel();

  {
    // Create a function pass manager for this engine
    std::unique_ptr<FunctionPassManager> FPM(new FunctionPassManager(module_));

// Set up the optimizer pipeline.  Start with registering info about how the
// target lays out data structures.
#if LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR == 6
    // LLVM 3.6.0 change
    module_->setDataLayout(engine_->getDataLayout());
    FPM->add(new llvm::DataLayoutPass());
#elif LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR == 5
    // LLVM 3.5.0
    auto target_layout = engine_->getTargetMachine()->getDataLayout();
    module_->setDataLayout(target_layout);
    FPM->add(new llvm::DataLayoutPass(*engine_->getDataLayout()));
#elif LLVM_VERSION_MAJOR > 3 || LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR >= 7
// Apparently no need to set DataLayout
#else
#error Unsupported LLVM version
#endif
    pmb.populateFunctionPassManager(*FPM);
    FPM->doInitialization();
    for (int i = 0; i < functions_.size(); i++) {
      if (functions_[i] == nullptr)
        continue;
      FPM->run(*functions_[i]->function());
    }
  }

  std::string codestr;
  {
    // In LLVM 3.7 for some reason the string is not saved
    // until the stream is destroyed - even though there is a
    // flush; so we introduce a scope here to ensure destruction
    // of the stream
    llvm::raw_string_ostream ostream(codestr);
#if LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR < 7
    llvm::formatted_raw_ostream formatted_stream(ostream);
#else
    llvm::buffer_ostream formatted_stream(ostream);
#endif

    // Also in 3.7 the pass manager seems to hold on to the stream
    // so we need to ensure that the stream outlives the pass manager
    std::unique_ptr<PassManager> MPM(new PassManager());
#if LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR == 6
    MPM->add(new llvm::DataLayoutPass());
#elif LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR == 5
    MPM->add(new llvm::DataLayoutPass(*engine_->getDataLayout()));
#endif
    pmb.populateModulePassManager(*MPM);

    for (int i = 0; dumpAsm && i < 1; i++) {
      llvm::TargetMachine *TM = engine_->getTargetMachine();
      if (!TM) {
        llvm::errs() << "unable to dump assembly\n";
        break;
      }
      if (TM->addPassesToEmitFile(*MPM, formatted_stream,
#if LLVM_VERSION_MAJOR >= 7
                                  nullptr,  // DWO output file
#endif
                                  llvm::TargetMachine::CGFT_AssemblyFile)) {
        llvm::errs() << "unable to add passes for generating assemblyfile\n";
        break;
      }
    }
    MPM->run(*module_);

// Note that in 3.7 this flus appears to have no effect
#if LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR <= 7
    formatted_stream.flush();
#endif
  }
  if (dumpAsm && codestr.length() > 0)
    llvm::errs() << codestr << "\n";
#endif
}

void RaviJITModule::finalize(bool doDump) {
  lua_assert(module_);
  if (!module_)
    return;
#if !USE_ORC_JIT
  // Following will generate very verbose dump when machine code is
  // produced below
  llvm::TargetMachine *TM = engine_->getTargetMachine();
  // TM->setOptLevel(llvm::CodeGenOpt::None);
  if (doDump) {
    TM->Options.PrintMachineCode = 1;
  }

  // Upon creation, MCJIT holds a pointer to the Module object
  // that it received from EngineBuilder but it does not immediately
  // generate code for this module. Code generation is deferred
  // until either the MCJIT::finalizeObject method is called
  // explicitly or a function such as MCJIT::getPointerToFunction
  // is called which requires the code to have been generated.
  engine_->finalizeObject();
#elif !USE_ORCv2_JIT
  // With ORC api, the module gets compiled when it is added
  // The optimization passes are run via the callback
  module_handle_ = owner()->addModule(std::move(module_));
#else
  llvm::cantFail(owner()->addModule(std::move(module_)));
#endif
  for (int i = 0; i < functions_.size(); i++) {
    if (functions_[i] == nullptr)
      continue;
    functions_[i]->setFunctionPtr();
  }
}

// Retrieve the JITed function from the
// execution engine and store it in ptr_
// Also associate the JITed function with the
// Lua Proto structure
void RaviJITFunction::setFunctionPtr() {
  lua_assert(ptr_ == nullptr);
  // function_ may be nullptr if it was obtained by name from the module, so
  // we need to check that
#if !USE_ORC_JIT
  if (function_) {
    ptr_ = engine()->getPointerToFunction(function_);
    *func_ptrptr_ = (lua_CFunction)ptr_;
  }
#else
  if (function_) {
    auto symbol = owner()->findSymbol(name());
    if (symbol) {
#if USE_ORCv2_JIT
      ptr_ = (void *)(intptr_t)(symbol->getAddress());
#else
      ptr_ = (void *)(intptr_t)llvm::cantFail(symbol.getAddress());
#endif
      *func_ptrptr_ = (lua_CFunction)ptr_;
    }
  }
#endif
}

llvm::Function *RaviJITModule::addExternFunction(llvm::FunctionType *type, void *address, const std::string &name) {
  auto fn = external_symbols_.find(name);
  if (fn != external_symbols_.end())
    return fn->second;
  llvm::Function *f = llvm::Function::Create(type, llvm::Function::ExternalLinkage, name, module());
  f->setDoesNotThrow();
  // We should have been able to call
  // engine_->addGlobalMapping() but this doesn't work
  // See http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-April/071856.html
  // See bug report http://llvm.org/bugs/show_bug.cgi?id=20656
  // following will call DynamicLibrary::AddSymbol
  owner_->addGlobalSymbol(name, address);
  external_symbols_[name] = f;
  return f;
}

void RaviJITModule::dump() {
#if LLVM_VERSION_MAJOR < 5
  if (module_)
    module_->dump();
#endif
}

// Dumps the machine code
// Will execute the passes as required by currently set
// optimization level; this may or may not match the actual
// JITed code which would have used the optimzation level set at the
// time of compilation
void RaviJITModule::dumpAssembly() { runpasses(true); }

std::unique_ptr<RaviJITState> RaviJITStateFactory::newJITState() {
  return std::unique_ptr<RaviJITState>(new RaviJITState());
}
}  // namespace ravi

// Initialize the JIT State and attach it to the
// Global Lua State
// If a JIT State already exists then this function
// will return -1
int raviV_initjit(struct lua_State *L) {
  global_State *G = G(L);
  if (G->ravi_state != NULL)
    return -1;
  ravi_State *jit = (ravi_State *)calloc(1, sizeof(ravi_State));
  jit->jit = new ravi::RaviJITState();
  jit->code_generator = new ravi::RaviCodeGenerator((ravi::RaviJITState *)jit->jit);
  G->ravi_state = jit;
  return 0;
}

// Free up the JIT State
void raviV_close(struct lua_State *L) {
  global_State *G = G(L);
  if (G->ravi_state == NULL)
    return;
  delete G->ravi_state->code_generator;
  delete G->ravi_state->jit;
  free(G->ravi_state);
}

// Compile a Lua function
// If JIT is turned off then compilation is skipped
// Compilation occurs if either auto compilation is ON (subject to some
// thresholds)
// or if a manual compilation request was made
// Returns true if compilation was successful
int raviV_compile(struct lua_State *L, struct Proto *p, ravi_compile_options_t *options) {
  if (p->ravi_jit.jit_function)
    return 1;
  global_State *G = G(L);
  if (G->ravi_state == NULL)
    return 0;
  if (!G->ravi_state->jit->is_enabled()) {
    return 0;
  }
  if (G->ravi_state->jit->get_compiling_flag()) {
    return 0;
  }
  bool doCompile = (bool)(options && options->manual_request != 0);
  if (!doCompile && G->ravi_state->jit->is_auto()) {
    if (p->ravi_jit.jit_flags == RAVI_JIT_FLAG_HASFORLOOP) /* function has fornum loop, so compile */
      doCompile = true;
    else if (p->sizecode > G->ravi_state->jit->get_mincodesize()) /* function is long so compile */
      doCompile = true;
    else {
      if (p->ravi_jit.execution_count < G->ravi_state->jit->get_minexeccount()) /* function has been executed many
                                                                                   times so compile */
        p->ravi_jit.execution_count++;
      else
        doCompile = true;
    }
  }
  if (doCompile) {
    auto module = std::make_shared<ravi::RaviJITModule>(G->ravi_state->jit);
    if (G->ravi_state->jit->is_use_dmrc() ? G->ravi_state->code_generator->alt_compile(L, p, module, options)
                                          : G->ravi_state->code_generator->compile(L, p, module, options)) {
      module->runpasses();
      module->finalize(G->ravi_state->jit->get_verbosity() == 3);
    }
  }
  return p->ravi_jit.jit_function != nullptr;
}

// Compile a bunch of Lua functions
// And put them all in one module
// Returns true if compilation was successful
int raviV_compile_n(struct lua_State *L, struct Proto *p[], int n, ravi_compile_options_t *options) {
  global_State *G = G(L);
  int count = 0;
  if (G->ravi_state->jit->get_compiling_flag())
    return 0;
  auto module = std::make_shared<ravi::RaviJITModule>(G->ravi_state->jit);
  for (int i = 0; i < n; i++) {
    if (G->ravi_state->jit->is_use_dmrc() ? G->ravi_state->code_generator->alt_compile(L, p[i], module, options)
                                          : G->ravi_state->code_generator->compile(L, p[i], module, options))
      count++;
  }
  if (count) {
    module->runpasses();
    module->finalize(G->ravi_state->jit->get_verbosity() == 3);
  }
  return count > 0;
}

// Free the JIT compiled function
// Note that this is called by the garbage collector
void raviV_freeproto(struct lua_State *L, struct Proto *p) {
  ravi::RaviJITFunction *f = reinterpret_cast<ravi::RaviJITFunction *>(p->ravi_jit.jit_data);
  if (f)
    delete f;
  p->ravi_jit.jit_status = RAVI_JIT_NOT_COMPILED;
  p->ravi_jit.jit_function = NULL;
  p->ravi_jit.jit_data = NULL;
  p->ravi_jit.execution_count = 0;
}

// Dump the LLVM IR
void raviV_dumpIR(struct lua_State *L, struct Proto *p) {
  if (p->ravi_jit.jit_status == RAVI_JIT_COMPILED) /* compiled */ {
    ravi::RaviJITFunction *f = reinterpret_cast<ravi::RaviJITFunction *>(p->ravi_jit.jit_data);
    if (f)
      f->dump();
  }
}

// Dump the LLVM ASM
void raviV_dumpASM(struct lua_State *L, struct Proto *p) {
  if (p->ravi_jit.jit_status == RAVI_JIT_COMPILED) /* compiled */ {
    ravi::RaviJITFunction *f = reinterpret_cast<ravi::RaviJITFunction *>(p->ravi_jit.jit_data);
    if (f)
      f->dumpAssembly();
  }
}

void raviV_setminexeccount(lua_State *L, int value) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return;
  G->ravi_state->jit->set_minexeccount(value);
}
int raviV_getminexeccount(lua_State *L) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return 0;
  return G->ravi_state->jit->get_minexeccount();
}

void raviV_setmincodesize(lua_State *L, int value) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return;
  G->ravi_state->jit->set_mincodesize(value);
}
int raviV_getmincodesize(lua_State *L) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return 0;
  return G->ravi_state->jit->get_mincodesize();
}

void raviV_setauto(lua_State *L, int value) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return;
  G->ravi_state->jit->set_auto(value != 0);
}
int raviV_getauto(lua_State *L) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return 0;
  return G->ravi_state->jit->is_auto();
}

// Turn on/off the JIT compiler
void raviV_setjitenabled(lua_State *L, int value) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return;
  G->ravi_state->jit->set_enabled(value != 0);
}
int raviV_getjitenabled(lua_State *L) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return 0;
  return G->ravi_state->jit->is_enabled();
}

void raviV_setoptlevel(lua_State *L, int value) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return;
  G->ravi_state->jit->set_optlevel(value);
}
int raviV_getoptlevel(lua_State *L) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return 0;
  return G->ravi_state->jit->get_optlevel();
}

void raviV_setsizelevel(lua_State *L, int value) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return;
  G->ravi_state->jit->set_sizelevel(value);
}
int raviV_getsizelevel(lua_State *L) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return 0;
  return G->ravi_state->jit->get_sizelevel();
}

void raviV_setverbosity(lua_State *L, int value) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return;
  G->ravi_state->jit->set_verbosity(value);
}
int raviV_getverbosity(lua_State *L) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return 0;
  return G->ravi_state->jit->get_verbosity();
}

void raviV_setvalidation(lua_State *L, int value) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return;
  G->ravi_state->jit->set_validation(value != 0);
}
int raviV_getvalidation(lua_State *L) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return 0;
  return G->ravi_state->jit->get_validation();
}

void raviV_setgcstep(lua_State *L, int value) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return;
  G->ravi_state->jit->set_gcstep(value);
}
int raviV_getgcstep(lua_State *L) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return 0;
  return G->ravi_state->jit->get_gcstep();
}

// Turn on/off the JIT compiler
void raviV_settraceenabled(lua_State *L, int value) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return;
  G->ravi_state->jit->set_tracehook_enabled(value != 0);
}
int raviV_gettraceenabled(lua_State *L) {
  global_State *G = G(L);
  if (!G->ravi_state)
    return 0;
  return G->ravi_state->jit->is_tracehook_enabled();
}

extern "C" int ravi_compile_C(lua_State *L) { return 0; }