//===-- DynamicLinker.cpp - Implement DynamicLinker interface -------------===//
// 
//                     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.
// 
//===----------------------------------------------------------------------===//
//
// Lightweight interface to dynamic library linking and loading, and dynamic
// symbol lookup functionality, in whatever form the operating system
// provides it.
//
// Possible future extensions include support for the HPUX shl_load()
// interface, the Mac OS X NSLinkModule() interface, and the Windows
// LoadLibrary() interface.
//
// Note that we assume that if dlopen() is available, then dlsym() is too.
//
//===----------------------------------------------------------------------===//

#include "Support/DynamicLinker.h"
#include "Config/dlfcn.h"
#include <cassert>

namespace llvm {

bool LinkDynamicObject (const char *filename, std::string *ErrorMessage) {
#if defined (HAVE_DLOPEN)
  if (dlopen (filename, RTLD_NOW | RTLD_GLOBAL) == 0) {
    if (ErrorMessage) *ErrorMessage = dlerror ();
    return true;
  }
  return false;
#else
  assert (0 && "Dynamic object linking not implemented for this platform");
#endif
}

void *GetAddressOfSymbol (const char *symbolName) {
#if defined (HAVE_DLOPEN)
#ifdef RTLD_DEFAULT
  return dlsym (RTLD_DEFAULT, symbolName);
#else
  static void* CurHandle = dlopen(0, RTLD_LAZY);
  return dlsym(CurHandle, symbolName);
#endif
#else
  assert (0 && "Dynamic symbol lookup not implemented for this platform");
#endif
}

// soft, cushiony C++ interface.
void *GetAddressOfSymbol (const std::string &symbolName) {
  return GetAddressOfSymbol (symbolName.c_str ());
}

} // End llvm namespace