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 #ifdef __GNUG__
  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/hash.h"
  29 #include "wx/module.h"
  30
  31
  32 // Ugh, I'd much rather this was typesafe, but no time
  33 // to rewrite wxHashTable right now..
  34
  35 typedef wxHashTable wxDLManifest;
  36 typedef wxHashTable wxDLImports;
  37
  38 // ----------------------------------------------------------------------------
  39 // conditional compilation
  40 // ----------------------------------------------------------------------------
  41
  42     // Note: WXPM/EMX has to be tested first, since we want to use
  43     // native version, even if configure detected presence of DLOPEN.
  44
  45 #if defined(__WXPM__) || defined(__EMX__)
  46 #define INCL_DOS
  47 #include <os2.h>
  48     typedef HMODULE wxDllType;
  49 #elif defined(HAVE_DLOPEN)
  50 #include <dlfcn.h>
  51     typedef void *wxDllType;
  52 #elif defined(HAVE_SHL_LOAD)
  53 #include <dl.h>
  54     typedef shl_t wxDllType;
  55 #elif defined(__WINDOWS__)
  56 #include <windows.h>         // needed to get HMODULE
  57     typedef HMODULE wxDllType;
  58 #elif defined(__DARWIN__)
  59     typedef void *wxDllType;
  60 #elif defined(__WXMAC__)
  61     typedef CFragConnectionID wxDllType;
  62 #else
  63 #error "wxLibrary can't be compiled on this platform, sorry."
  64 #endif
  65
  66     // LoadLibrary is defined in windows.h as LoadLibraryA, but wxDllLoader
  67     // method should be called LoadLibrary, not LoadLibraryA or LoadLibraryW!
  68
  69 #if defined(__WIN32__) && defined(LoadLibrary)
  70 #   include "wx/msw/winundef.h"
  71 #endif
  72
  73
  74 // ---------------------------------------------------------------------------
  75 // wxDllLoader
  76 // ---------------------------------------------------------------------------
  77
  78     //  Cross platform wrapper for dlopen and friends.
  79     //  There are no instances of this class, it simply
  80     //  serves as a namespace for its static member functions.
  81
  82 class WXDLLEXPORT wxDllLoader
  83 {
  84 public:
  85
  86         // libname may be either the full path to the file or just the filename
  87         // in which case the library is searched for in all standard locations.
  88         // The platform specific library extension is automatically appended.
  89
  90     static wxDllType    Load(const wxString& name);
  91
  92         // The same as Load, except 'name' is searched for without modification.
  93
  94     static wxDllType    LoadLibrary(const wxString& name);
  95     static void         UnloadLibrary(wxDllType dll);
  96
  97         // return a valid handle for the main program itself or NULL if
  98         // back linking is not supported by the current platform (e.g. Win32)
  99
 100     static wxDllType GetProgramHandle();
 101
 102         // resolve a symbol in a loaded DLL, such as a variable or function
 103         // name.  dllHandle is a handle previously returned by LoadLibrary(),
 104         // symbol is the (possibly mangled) name of the symbol.
 105         // (use extern "C" to export unmangled names)
 106         //
 107         // Since it is perfectly valid for the returned symbol to actually be
 108         // NULL, that is not always indication of an error.  Pass and test the
 109         // parameter 'success' for a true indication of success or failure to
 110         // load the symbol.
 111         //
 112         // Returns a pointer to the symbol on success.
 113
 114     static void *GetSymbol(wxDllType dllHandle, const wxString &name, bool *success = 0);
 115
 116         // return the platform standard DLL extension (with leading dot)
 117
 118     static const wxString &GetDllExt() { return ms_dllext; }
 119
 120 private:
 121
 122     wxDllLoader();                    // forbid construction of objects
 123     static const wxString ms_dllext;  // Platform specific shared lib suffix.
 124 };
 125
 126
 127 // ---------------------------------------------------------------------------
 128 // wxDynamicLibrary
 129 // ---------------------------------------------------------------------------
 130
 131 class wxDLManifestEntry
 132 {
 133 public:
 134
 135     static wxDLImports ms_classes;  // Static hash of all imported classes.
 136
 137     wxDLManifestEntry( const wxString &libname );
 138     ~wxDLManifestEntry();
 139
 140     wxDLManifestEntry  *Ref() { ++m_count; return this; }
 141     bool                Unref() { return (m_count-- < 2) ? (delete this, TRUE) : FALSE; }
 142
 143     bool                IsLoaded() const { return m_count > 0; }
 144
 145     wxDllType           GetLinkHandle() const { return m_handle; }
 146     wxDllType           GetProgramHandle() const { return wxDllLoader::GetProgramHandle(); }
 147     void               *GetSymbol(const wxString &symbol, bool *success = 0)
 148     {
 149         return wxDllLoader::GetSymbol( m_handle, symbol, success );
 150     }
 151
 152 private:
 153
 154         // Order of these three *is* important, do not change it
 155
 156     wxClassInfo          *m_before;    // sm_first before loading this lib
 157     wxDllType             m_handle;    // Handle from dlopen.
 158     wxClassInfo          *m_after;     // ..and after.
 159
 160     size_t                m_count;     // Ref count of Link and Create calls.
 161     wxModuleList          m_wxmodules; // any wxModules that we initialised.
 162
 163     void    UpdateClassInfo();       // Update the wxClassInfo table
 164     void    RestoreClassInfo();      // Restore the original wxClassInfo state.
 165     void    RegisterModules();       // Init any wxModules in the lib.
 166     void    UnregisterModules();     // Cleanup any wxModules we installed.
 167
 168 DECLARE_NO_COPY_CLASS(wxDLManifestEntry)
 169 };
 170
 171
 172 class WXDLLEXPORT wxDynamicLibrary
 173 {
 174 public:
 175
 176         // Static accessors.
 177
 178     static wxDLManifestEntry    *Link(const wxString &libname);
 179     static bool                  Unlink(const wxString &libname);
 180
 181         // Instance methods.
 182
 183     wxDynamicLibrary(const wxString &libname);
 184     ~wxDynamicLibrary();
 185
 186     bool   IsLoaded() const { return m_entry && m_entry->IsLoaded(); }
 187     void  *GetSymbol(const wxString &symbol, bool *success = 0)
 188     {
 189         return m_entry->GetSymbol( symbol, success );
 190     }
 191
 192 private:
 193
 194     static wxDLManifest  ms_manifest;  // Static hash of loaded libs.
 195     wxDLManifestEntry   *m_entry;      // Cache our entry in the manifest.
 196
 197     // We could allow this class to be copied if we really
 198     // wanted to, but not without modification.
 199
 200 DECLARE_NO_COPY_CLASS(wxDynamicLibrary)
 201 };
 202
 203
 204 #endif  // wxUSE_DYNAMIC_LOADER
 205 #endif  // _WX_DYNAMICLOADER_H__
 206
 207 // vi:sts=4:sw=4:et