ENH: Adding kwsys implementation for a DynamicLoader class. Copy from...

ENH: Adding kwsys implementation for a DynamicLoader class. Copy from itkDynamicLoader, with patch from cmDynamicLoader

DynamicLoader.cxx

+/*=========================================================================
+
+  Program:   KWSys - Kitware System Library
+  Module:    DynamicLoader.cxx
+
+  Copyright (c) Kitware, Inc., Insight Consortium.  All rights reserved.
+  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
+
+     This software is distributed WITHOUT ANY WARRANTY; without even
+     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+     PURPOSE.  See the above copyright notices for more information.
+
+=========================================================================*/
+#include "kwsysPrivate.h"
+#include KWSYS_HEADER(DynamicLoader.hxx)
+
+#include KWSYS_HEADER(Configure.hxx)
+
+// Work-around CMake dependency scanning limitation.  This must
+// duplicate the above list of headers.
+#if 0
+# include "DynamicLoader.hxx.in"
+# include "Configure.hxx.in"
+#endif
+
+// This file is actually 3 different implementations.
+// 1. HP machines which uses shl_load
+// 2. Power PC MAC which uses GetSharedLibrary
+// 3. Windows which uses LoadLibrary
+// 4. Most unix systems which use dlopen (default )
+// Each part of the ifdef contains a complete implementation for
+// the static methods of DynamicLoader.  
+
+namespace KWSYS_NAMESPACE
+{
+
+//----------------------------------------------------------------------------
+DynamicLoader::DynamicLoader()
+{
+}
+
+//----------------------------------------------------------------------------
+DynamicLoader::~DynamicLoader()
+{
+}
+
+}
+
+// ---------------------------------------------------------------
+// 1. Implementation for HPUX  machines
+#ifdef __hpux
+#include <dl.h>
+#define DYNAMICLOADER_DEFINED 1
+
+namespace KWSYS_NAMESPACE
+{
+
+//----------------------------------------------------------------------------
+LibHandle DynamicLoader::OpenLibrary(const char* libname )
+{
+  return shl_load(libname, BIND_DEFERRED | DYNAMIC_PATH, 0L);
+}
+
+//----------------------------------------------------------------------------
+int DynamicLoader::CloseLibrary(LibHandle lib)
+{
+  return !shl_unload(lib);
+}
+
+//----------------------------------------------------------------------------
+DynamicLoaderFunction
+DynamicLoader::GetSymbolAddress(LibHandle lib, const char* sym)
+{ 
+  void* addr;
+  int status;
+  
+  status = shl_findsym (&lib, sym, TYPE_PROCEDURE, &addr);
+  void* result = (status < 0) ? (void*)0 : addr;
+  
+  // Hack to cast pointer-to-data to pointer-to-function.
+  return *reinterpret_cast<DynamicLoaderFunction*>(&result);
+}
+
+//----------------------------------------------------------------------------
+const char* DynamicLoader::LibPrefix()
+{ 
+  return "lib";
+}
+
+//----------------------------------------------------------------------------
+const char* DynamicLoader::LibExtension()
+{
+  return ".sl";
+}
+
+//----------------------------------------------------------------------------
+const char* DynamicLoader::LastError()
+{
+  // TODO: Need implementation with errno/strerror
+  /* If successful, shl_findsym returns an integer (int) value zero. If 
+   * shl_findsym cannot find sym, it returns -1 and sets errno to zero. 
+   * If any other errors occur, shl_findsym returns -1 and sets errno to one 
+   * of these values (defined in <errno.h>):
+   * ENOEXEC
+   * A format error was detected in the specified library.
+   * ENOSYM
+   * A symbol on which sym depends could not be found.
+   * EINVAL
+   * The specified handle is invalid.
+   */
+
+  return 0;
+}
+
+} // namespace KWSYS_NAMESPACE
+
+#endif //__hpux
+
+
+// ---------------------------------------------------------------
+// 2. Implementation for Mac OS X 10.2.x and earlier
+#ifdef __APPLE__
+#if MAC_OS_X_VERSION_MIN_REQUIRED < 1030
+#include <mach-o/dyld.h>
+#define DYNAMICLOADER_DEFINED 1
+
+namespace KWSYS_NAMESPACE
+{
+
+//----------------------------------------------------------------------------
+LibHandle DynamicLoader::OpenLibrary(const char* libname )
+{
+  NSObjectFileImageReturnCode rc;
+  NSObjectFileImage image = 0;
+  
+  rc = NSCreateObjectFileImageFromFile(libname, &image);
+  if(!image)
+    {
+    return 0;
+    }
+  return NSLinkModule(image, libname, NSLINKMODULE_OPTION_BINDNOW);
+}
+
+//----------------------------------------------------------------------------
+int DynamicLoader::CloseLibrary( LibHandle lib)
+{
+  DYLD_BOOL success = NSUnLinkModule(lib, NSUNLINKMODULE_OPTION_NONE);
+  return success;
+}
+
+//----------------------------------------------------------------------------
+DynamicLoaderFunction DynamicLoader::GetSymbolAddress(LibHandle /* lib */, const char* sym)
+{ 
+  void *result=0;
+  if(NSIsSymbolNameDefined(sym))
+    {
+    NSSymbol symbol= NSLookupAndBindSymbol(sym);
+    if(symbol)
+      {
+      result = NSAddressOfSymbol(symbol);
+      }
+    }
+  // Hack to cast pointer-to-data to pointer-to-function.
+  return *reinterpret_cast<DynamicLoaderFunction*>(&result);
+}
+
+//----------------------------------------------------------------------------
+const char* DynamicLoader::LibPrefix()
+{ 
+  return "";
+}
+
+//----------------------------------------------------------------------------
+const char* DynamicLoader::LibExtension()
+{
+  return ".dylib";
+}
+
+//----------------------------------------------------------------------------
+const char* DynamicLoader::LastError()
+{
+  return 0;
+}
+
+} // namespace KWSYS_NAMESPACE
+
+#endif //MAC_OS_X_VERSION_MIN_REQUIRED < 1030
+#endif // __APPLE__
+
+// ---------------------------------------------------------------
+// 3. Implementation for Windows win32 code
+#ifdef _WIN32
+#include <windows.h>
+#define DYNAMICLOADER_DEFINED 1
+
+namespace KWSYS_NAMESPACE
+{
+  
+//----------------------------------------------------------------------------
+LibHandle DynamicLoader::OpenLibrary(const char* libname)
+{
+  LibHandle lh;
+#ifdef UNICODE
+  wchar_t libn[MB_CUR_MAX];
+  mbstowcs(libn, libname, MB_CUR_MAX);
+  lh = LoadLibrary(libn);
+#else
+  lh = LoadLibrary(libname);
+#endif
+  return lh;
+}
+
+//----------------------------------------------------------------------------
+int DynamicLoader::CloseLibrary(LibHandle lib)
+{
+  return (int)FreeLibrary(lib);
+}
+
+//----------------------------------------------------------------------------
+DynamicLoaderFunction DynamicLoader::GetSymbolAddress(LibHandle lib, const char* sym)
+{ 
+  void *result;
+#ifdef UNICODE
+  wchar_t wsym[MB_CUR_MAX];
+  mbstowcs(wsym, sym, MB_CUR_MAX);
+  result = GetProcAddress(lib, wsym);
+#else
+  result = (void*)GetProcAddress(lib, sym);
+#endif
+  // Hack to cast pointer-to-data to pointer-to-function.
+  return *reinterpret_cast<DynamicLoaderFunction*>(&result);
+}
+
+//----------------------------------------------------------------------------
+const char* DynamicLoader::LibPrefix()
+{ 
+  return "";
+}
+
+//----------------------------------------------------------------------------
+const char* DynamicLoader::LibExtension()
+{
+  return ".dll";
+}
+
+//----------------------------------------------------------------------------
+const char* DynamicLoader::LastError()
+{
+  LPVOID lpMsgBuf;
+
+  FormatMessage( 
+    FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
+    NULL,
+    GetLastError(),
+    MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
+    (LPTSTR) &lpMsgBuf,
+    0,
+    NULL 
+    );
+  
+  static char* str = 0;
+  delete [] str;
+  str = strcpy(new char[strlen((char*)lpMsgBuf)+1], (char*)lpMsgBuf);
+  // Free the buffer.
+  LocalFree( lpMsgBuf );
+  return str;
+}
+
+} // namespace KWSYS_NAMESPACE
+
+#endif //_WIN32
+
+// ---------------------------------------------------------------
+// 4. Implementation for default UNIX machines.
+// if nothing has been defined then use this
+#ifndef DYNAMICLOADER_DEFINED
+#define DYNAMICLOADER_DEFINED 1
+// Setup for most unix machines
+#include <dlfcn.h>
+
+namespace KWSYS_NAMESPACE
+{
+  
+//----------------------------------------------------------------------------
+LibHandle DynamicLoader::OpenLibrary(const char* libname )
+{
+  return dlopen(libname, RTLD_LAZY);
+}
+
+//----------------------------------------------------------------------------
+int DynamicLoader::CloseLibrary(LibHandle lib)
+{
+  if (lib)
+    {
+    // The function dlclose() returns 0 on success, and non-zero on error.
+    return !(int)dlclose(lib);
+    }
+  // else
+  return 0;
+}
+
+//----------------------------------------------------------------------------
+DynamicLoaderFunction DynamicLoader::GetSymbolAddress(LibHandle lib, const char* sym)
+{ 
+  void* result = dlsym(lib, sym);
+  
+  // Hack to cast pointer-to-data to pointer-to-function.
+  return *reinterpret_cast<DynamicLoaderFunction*>(&result);
+}
+
+//----------------------------------------------------------------------------
+const char* DynamicLoader::LibPrefix()
+{ 
+  return "lib";
+}
+
+//----------------------------------------------------------------------------
+const char* DynamicLoader::LibExtension()
+{
+  return ".so";
+}
+
+//----------------------------------------------------------------------------
+const char* DynamicLoader::LastError()
+{
+  return dlerror(); 
+}
+
+} // namespace KWSYS_NAMESPACE
+
+#endif

DynamicLoader.hxx.in

+/*=========================================================================
+
+  Program:   KWSys - Kitware System Library
+  Module:    DynamicLoader.hxx.in
+
+  Copyright (c) Kitware, Inc., Insight Consortium.  All rights reserved.
+  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
+
+     This software is distributed WITHOUT ANY WARRANTY; without even
+     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+     PURPOSE.  See the above copyright notices for more information.
+
+=========================================================================*/
+#ifndef @KWSYS_NAMESPACE@_DynamicLoader_hxx
+#define @KWSYS_NAMESPACE@_DynamicLoader_hxx
+
+#include <@KWSYS_NAMESPACE@/Configure.h>
+
+namespace @KWSYS_NAMESPACE@
+{
+// Ugly stuff for library handles
+// They are different on several different OS's
+#if defined(__hpux)
+  #include <dl.h>
+  typedef shl_t LibHandle;
+#elif defined(_WIN32)
+  #include <windows.h>
+  typedef HMODULE LibHandle;
+#elif defined(__APPLE__)
+  #include <AvailabilityMacros.h>
+  #if MAC_OS_X_VERSION_MIN_REQUIRED < 1030
+    #include <mach-o/dyld.h>
+    typedef NSModule LibHandle;
+  #else
+    typedef void* LibHandle;
+  #endif
+#else
+  typedef void* LibHandle;
+#endif
+} // namespace @KWSYS_NAMESPACE@
+
+namespace @KWSYS_NAMESPACE@
+{
+// Return type from DynamicLoader::GetSymbolAddress.
+typedef void (*DynamicLoaderFunction)();
+
+/** \class DynamicLoader
+ * \brief Portable loading of dynamic libraries or dll's.
+ *
+ * DynamicLoader provides a portable interface to loading dynamic
+ * libraries or dll's into a process.
+ *
+ * Directory currently works with Windows, Apple, HP-UX and Unix (POSIX)
+ * operating systems
+ */
+
+class @KWSYS_NAMESPACE@_EXPORT DynamicLoader
+{
+public:
+  DynamicLoader();
+  ~DynamicLoader();
+
+  /** Load a dynamic library into the current process.
+   * The returned LibHandle can be used to access the symbols in the
+   * library. */
+  static LibHandle OpenLibrary(const char*);
+
+  /** Attempt to detach a dynamic library from the
+   * process.  A value of true is returned if it is sucessful. */
+  static int CloseLibrary(LibHandle);
+
+  /** Find the address of the symbol in the given library. */
+  static DynamicLoaderFunction GetSymbolAddress(LibHandle, const char*);
+
+  /** Return the library prefix for the given architecture */
+  static const char* LibPrefix();
+
+  /** Return the library extension for the given architecture. */
+  static const char* LibExtension();
+
+  /** Return the last error produced from a calls made on this class. */
+  static const char* LastError();
+}; // End Class: DynamicLoader
+
+} // namespace @KWSYS_NAMESPACE@
+
+#endif