path: root/lib/ExecutionEngine/ExecutionEngine.cpp

//===-- ExecutionEngine.cpp - Common Implementation shared by EEs ---------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the common interface used by the various execution engine
// subclasses.
//
//===----------------------------------------------------------------------===//

#define DEBUG_TYPE "jit"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/ModuleProvider.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Config/alloca.h"
#include "llvm/ExecutionEngine/ExecutionEngine.h"
#include "llvm/ExecutionEngine/GenericValue.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MutexGuard.h"
#include "llvm/System/DynamicLibrary.h"
#include "llvm/System/Host.h"
#include "llvm/Target/TargetData.h"
#include <math.h>
using namespace llvm;

STATISTIC(NumInitBytes, "Number of bytes of global vars initialized");
STATISTIC(NumGlobals  , "Number of global vars initialized");

ExecutionEngine::EECtorFn ExecutionEngine::JITCtor = 0;
ExecutionEngine::EECtorFn ExecutionEngine::InterpCtor = 0;

ExecutionEngine::ExecutionEngine(ModuleProvider *P) : LazyFunctionCreator(0) {
  LazyCompilationDisabled = false;
  Modules.push_back(P);
  assert(P && "ModuleProvider is null?");
}

ExecutionEngine::~ExecutionEngine() {
  clearAllGlobalMappings();
  for (unsigned i = 0, e = Modules.size(); i != e; ++i)
    delete Modules[i];
}

/// removeModuleProvider - Remove a ModuleProvider from the list of modules.
/// Release module from ModuleProvider.
Module* ExecutionEngine::removeModuleProvider(ModuleProvider *P, 
                                              std::string *ErrInfo) {
  for(SmallVector<ModuleProvider *, 1>::iterator I = Modules.begin(), 
        E = Modules.end(); I != E; ++I) {
    ModuleProvider *MP = *I;
    if (MP == P) {
      Modules.erase(I);
      return MP->releaseModule(ErrInfo);
    }
  }
  return NULL;
}

/// FindFunctionNamed - Search all of the active modules to find the one that
/// defines FnName.  This is very slow operation and shouldn't be used for
/// general code.
Function *ExecutionEngine::FindFunctionNamed(const char *FnName) {
  for (unsigned i = 0, e = Modules.size(); i != e; ++i) {
    if (Function *F = Modules[i]->getModule()->getFunction(FnName))
      return F;
  }
  return 0;
}


/// addGlobalMapping - Tell the execution engine that the specified global is
/// at the specified location.  This is used internally as functions are JIT'd
/// and as global variables are laid out in memory.  It can and should also be
/// used by clients of the EE that want to have an LLVM global overlay
/// existing data in memory.
void ExecutionEngine::addGlobalMapping(const GlobalValue *GV, void *Addr) {
  MutexGuard locked(lock);
  
  void *&CurVal = state.getGlobalAddressMap(locked)[GV];
  assert((CurVal == 0 || Addr == 0) && "GlobalMapping already established!");
  CurVal = Addr;
  
  // If we are using the reverse mapping, add it too
  if (!state.getGlobalAddressReverseMap(locked).empty()) {
    const GlobalValue *&V = state.getGlobalAddressReverseMap(locked)[Addr];
    assert((V == 0 || GV == 0) && "GlobalMapping already established!");
    V = GV;
  }
}

/// clearAllGlobalMappings - Clear all global mappings and start over again
/// use in dynamic compilation scenarios when you want to move globals
void ExecutionEngine::clearAllGlobalMappings() {
  MutexGuard locked(lock);
  
  state.getGlobalAddressMap(locked).clear();
  state.getGlobalAddressReverseMap(locked).clear();
}

/// updateGlobalMapping - Replace an existing mapping for GV with a new
/// address.  This updates both maps as required.  If "Addr" is null, the
/// entry for the global is removed from the mappings.
void ExecutionEngine::updateGlobalMapping(const GlobalValue *GV, void *Addr) {
  MutexGuard locked(lock);
  
  // Deleting from the mapping?
  if (Addr == 0) {
    state.getGlobalAddressMap(locked).erase(GV);
    if (!state.getGlobalAddressReverseMap(locked).empty())
      state.getGlobalAddressReverseMap(locked).erase(Addr);
    return;
  }
  
  void *&CurVal = state.getGlobalAddressMap(locked)[GV];
  if (CurVal && !state.getGlobalAddressReverseMap(locked).empty())
    state.getGlobalAddressReverseMap(locked).erase(CurVal);
  CurVal = Addr;
  
  // If we are using the reverse mapping, add it too
  if (!state.getGlobalAddressReverseMap(locked).empty()) {
    const GlobalValue *&V = state.getGlobalAddressReverseMap(locked)[Addr];