include/wx/dynload.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:         dynload.h
   3 // Purpose:      Dynamic loading framework
   4 // Author:       Ron Lee, David Falkinder, Vadim Zeitlin and a cast of 1000's
   5 //               (derived in part from dynlib.cpp (c) 1998 Guilhem Lavaux)
   6 // Modified by:
   7 // Created:      03/12/01
   8 // RCS-ID:       $Id$
   9 // Copyright:    (c) 2001 Ron Lee <ron@debian.org>
  10 // Licence:      wxWindows license
  11 /////////////////////////////////////////////////////////////////////////////
  12
  13 #ifndef _WX_DYNAMICLOADER_H__
  14 #define _WX_DYNAMICLOADER_H__
  15
  16 #if defined(__GNUG__) && !defined(__APPLE__)
  17 #pragma interface "dynload.h"
  18 #endif
  19
  20 // ----------------------------------------------------------------------------
  21 // headers
  22 // ----------------------------------------------------------------------------
  23
  24 #include "wx/defs.h"
  25
  26 #if wxUSE_DYNAMIC_LOADER
  27
  28 #include "wx/hashmap.h"
  29 #include "wx/module.h"
  30
  31 // FIXME: can this go in private.h or something too??
  32 #if defined(__WXPM__) || defined(__EMX__)
  33 #define INCL_DOS
  34 #include <os2.h>
  35 #endif
  36
  37 #ifdef __WXMSW__
  38 #include "wx/msw/private.h"
  39 #endif
  40
  41 class WXDLLEXPORT wxPluginLibrary;
  42
  43 WX_DECLARE_EXPORTED_STRING_HASH_MAP(wxPluginLibrary *, wxDLManifest);
  44 typedef wxDLManifest wxDLImports;
  45
  46 // ----------------------------------------------------------------------------
  47 // conditional compilation
  48 // ----------------------------------------------------------------------------
  49
  50     // Note: WXPM/EMX has to be tested first, since we want to use
  51     // native version, even if configure detected presence of DLOPEN.
  52
  53 #if defined(__WXPM__) || defined(__EMX__) || defined(__WINDOWS__)
  54 typedef HMODULE             wxDllType;
  55 #elif defined(HAVE_DLOPEN)
  56 #include <dlfcn.h>
  57 typedef void               *wxDllType;
  58 #elif defined(HAVE_SHL_LOAD)
  59 #include <dl.h>
  60 typedef shl_t               wxDllType;
  61 #elif defined(__DARWIN__)
  62 typedef void               *wxDllType;
  63 #elif defined(__WXMAC__)
  64 typedef CFragConnectionID   wxDllType;
  65 #else
  66 #error "Dynamic Loading classes can't be compiled on this platform, sorry."
  67 #endif
  68
  69
  70 // ---------------------------------------------------------------------------
  71 // wxDynamicLibrary
  72 // ---------------------------------------------------------------------------
  73
  74 //FIXME:  This class isn't really common at all, it should be moved
  75 //        into platform dependent files.
  76
  77 // NOTE: this class is (deliberately) not virtual, do not attempt
  78 //       to use it polymorphically.
  79
  80 enum wxDLFlags
  81 {
  82     wxDL_LAZY       = 0x00000001,   // resolve undefined symbols at first use
  83     wxDL_NOW        = 0x00000002,   // resolve undefined symbols on load
  84     wxDL_GLOBAL     = 0x00000004,   // export extern symbols to subsequently
  85                                     // loaded libs.
  86     wxDL_VERBATIM   = 0x00000008,   // Attempt to load the supplied library
  87                                     // name without appending the usual dll
  88                                     // filename extension.
  89
  90     wxDL_NOSHARE    = 0x00000010,   // load new DLL, don't reuse already loaded
  91
  92     // FIXME: why? (VZ)
  93 #ifdef __osf__
  94     wxDL_DEFAULT    = wxDL_LAZY
  95 #else
  96     wxDL_DEFAULT    = wxDL_LAZY | wxDL_GLOBAL
  97 #endif
  98 };
  99
 100
 101 class WXDLLEXPORT wxDynamicLibrary
 102 {
 103 public:
 104
 105         // return a valid handle for the main program itself or NULL if
 106         // back linking is not supported by the current platform (e.g. Win32)
 107
 108     static wxDllType         GetProgramHandle();
 109
 110         // return the platform standard DLL extension (with leading dot)
 111
 112     static const wxChar *GetDllExt() { return ms_dllext; }
 113
 114     wxDynamicLibrary() : m_handle(0) {}
 115     wxDynamicLibrary(wxString libname, int flags = wxDL_DEFAULT)
 116         : m_handle(0)
 117     {
 118         Load(libname, flags);
 119     }
 120     ~wxDynamicLibrary() { Unload(); }
 121
 122         // return TRUE if the library was loaded successfully
 123
 124     bool IsLoaded() const { return m_handle != 0; }
 125
 126         // load the library with the given name
 127         // (full or not), return TRUE on success
 128
 129     bool Load(wxString libname, int flags = wxDL_DEFAULT);
 130
 131         // unload the library, also done automatically in dtor
 132
 133     void Unload();
 134
 135         // Return the raw handle from dlopen and friends.
 136
 137     wxDllType GetLibHandle() const { return m_handle; }
 138
 139         // resolve a symbol in a loaded DLL, such as a variable or function
 140         // name.  'name' is the (possibly mangled) name of the symbol.
 141         // (use extern "C" to export unmangled names)
 142         //
 143         // Since it is perfectly valid for the returned symbol to actually be
 144         // NULL, that is not always indication of an error.  Pass and test the
 145         // parameter 'success' for a true indication of success or failure to
 146         // load the symbol.
 147         //
 148         // Returns a pointer to the symbol on success, or NULL if an error
 149         // occurred or the symbol wasn't found.
 150
 151     void *GetSymbol(const wxString& name, bool *success = 0) const;
 152
 153 #if WXWIN_COMPATIBILITY_2_2
 154     operator bool() const { return IsLoaded(); }
 155 #endif
 156
 157 protected:
 158
 159         // Platform specific shared lib suffix.
 160
 161     static const wxChar *ms_dllext;
 162
 163         // the handle to DLL or NULL
 164
 165     wxDllType m_handle;
 166
 167         // no copy ctor/assignment operators
 168         // or we'd try to unload the library twice
 169
 170     DECLARE_NO_COPY_CLASS(wxDynamicLibrary)
 171 };
 172
 173
 174 // ---------------------------------------------------------------------------
 175 // wxPluginLibrary
 176 // ---------------------------------------------------------------------------
 177
 178 // NOTE: Do not attempt to use a base class pointer to this class.
 179 //       wxDL is not virtual and we deliberately hide some of it's
 180 //       methods here.
 181 //
 182 //       Unless you know exacty why you need to, you probably shouldn't
 183 //       instantiate this class directly anyway, use wxPluginManager
 184 //       instead.
 185
 186 class WXDLLEXPORT wxPluginLibrary : public wxDynamicLibrary
 187 {
 188 public:
 189
 190     static wxDLImports* ms_classes;  // Static hash of all imported classes.
 191
 192     wxPluginLibrary( const wxString &libname, int flags = wxDL_DEFAULT );
 193     ~wxPluginLibrary();
 194
 195     wxPluginLibrary  *RefLib();
 196     bool              UnrefLib();
 197
 198         // These two are called by the PluginSentinel on (PLUGGABLE) object
 199         // creation/destruction.  There is usually no reason for the user to
 200         // call them directly.  We have to separate this from the link count,
 201         // since the two are not interchangeable.
 202
 203         // FIXME: for even better debugging PluginSentinel should register
 204         //        the name of the class created too, then we can state
 205         //        exactly which object was not destroyed which may be
 206         //        difficult to find otherwise.  Also this code should
 207         //        probably only be active in DEBUG mode, but let's just
 208         //        get it right first.
 209
 210     void  RefObj() { ++m_objcount; }
 211     void  UnrefObj()
 212     {
 213         wxASSERT_MSG( m_objcount > 0, _T("Too many objects deleted??") );
 214         --m_objcount;
 215     }
 216
 217         // Override/hide some base class methods
 218
 219     bool  IsLoaded() const { return m_linkcount > 0; }
 220     void  Unload() { UnrefLib(); }
 221
 222 private:
 223
 224     wxClassInfo    *m_before;       // sm_first before loading this lib
 225     wxClassInfo    *m_after;        // ..and after.
 226
 227     size_t          m_linkcount;    // Ref count of library link calls
 228     size_t          m_objcount;     // ..and (pluggable) object instantiations.
 229     wxModuleList    m_wxmodules;    // any wxModules that we initialised.
 230
 231     void    UpdateClassInfo();      // Update the wxClassInfo table
 232     void    RestoreClassInfo();     // Restore the original wxClassInfo state.
 233     void    RegisterModules();      // Init any wxModules in the lib.
 234     void    UnregisterModules();    // Cleanup any wxModules we installed.
 235
 236     DECLARE_NO_COPY_CLASS(wxPluginLibrary)
 237 };
 238
 239
 240 class WXDLLEXPORT wxPluginManager
 241 {
 242 public:
 243
 244         // Static accessors.
 245
 246     static wxPluginLibrary    *LoadLibrary( const wxString &libname,
 247                                             int flags = wxDL_DEFAULT );
 248     static bool                UnloadLibrary(const wxString &libname);
 249
 250         // This is used by wxDllLoader.  It's wrapped in the compatibility
 251         // macro because it's of arguable use outside of that.
 252
 253 #if WXWIN_COMPATIBILITY_2_2
 254     static wxPluginLibrary *GetObjectFromHandle(wxDllType handle);
 255 #endif
 256
 257         // Instance methods.
 258
 259     wxPluginManager() : m_entry(NULL) {};
 260     wxPluginManager(const wxString &libname, int flags = wxDL_DEFAULT)
 261     {
 262         Load(libname, flags);
 263     }
 264     ~wxPluginManager() { Unload(); }
 265
 266     bool   Load(const wxString &libname, int flags = wxDL_DEFAULT);
 267     void   Unload();
 268
 269     bool   IsLoaded() const { return m_entry && m_entry->IsLoaded(); }
 270     void  *GetSymbol(const wxString &symbol, bool *success = 0)
 271     {
 272         return m_entry->GetSymbol( symbol, success );
 273     }
 274
 275     static void CreateManifest() { ms_manifest = new wxDLManifest(wxKEY_STRING); }
 276     static void ClearManifest() { delete ms_manifest; ms_manifest = NULL; }
 277
 278 private:
 279     // return the pointer to the entry for the library with given name in
 280     // ms_manifest or NULL if none
 281     static wxPluginLibrary *FindByName(const wxString& name)
 282     {
 283         const wxDLManifest::iterator i = ms_manifest->find(name);
 284
 285         return i == ms_manifest->end() ? NULL : i->second;
 286     }
 287
 288     static wxDLManifest* ms_manifest;  // Static hash of loaded libs.
 289     wxPluginLibrary*     m_entry;      // Cache our entry in the manifest.
 290
 291     // We could allow this class to be copied if we really
 292     // wanted to, but not without modification.
 293     DECLARE_NO_COPY_CLASS(wxPluginManager)
 294 };
 295
 296
 297 // ---------------------------------------------------------------------------
 298 // wxDllLoader
 299 // ---------------------------------------------------------------------------
 300
 301     //  Cross platform wrapper for dlopen and friends.
 302     //  There are no instances of this class, it simply
 303     //  serves as a namespace for its static member functions.
 304
 305 #if WXWIN_COMPATIBILITY_2_2
 306 class WXDLLEXPORT wxDllLoader
 307 {
 308 public:
 309
 310     static wxDllType    LoadLibrary(const wxString& name, bool *success = NULL);
 311     static void         UnloadLibrary(wxDllType dll);
 312
 313     static wxDllType GetProgramHandle() { return wxDynamicLibrary::GetProgramHandle(); }
 314
 315     static void *GetSymbol(wxDllType dllHandle, const wxString &name, bool *success = 0);
 316
 317     static wxString GetDllExt() { return wxDynamicLibrary::GetDllExt(); }
 318
 319 private:
 320
 321     wxDllLoader();                    // forbid construction of objects
 322 };
 323 #endif
 324
 325 #endif  // wxUSE_DYNAMIC_LOADER
 326 #endif  // _WX_DYNAMICLOADER_H__
 327