wxWidgets/include/wx/dynload.h
Ron Lee 7c1e2b4401 reimplemented sanity checks that were lost/broken in the regrettably
far to hasty last minute pushmepullyou api changes.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@13131 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
2001-12-20 12:06:11 +00:00

228 lines
7.5 KiB
C++

/////////////////////////////////////////////////////////////////////////////
// Name: dynload.h
// Purpose: Dynamic loading framework
// Author: Ron Lee, David Falkinder, Vadim Zeitlin and a cast of 1000's
// (derived in part from dynlib.cpp (c) 1998 Guilhem Lavaux)
// Modified by:
// Created: 03/12/01
// RCS-ID: $Id$
// Copyright: (c) 2001 Ron Lee <ron@debian.org>
// Licence: wxWindows license
/////////////////////////////////////////////////////////////////////////////
#ifndef _WX_DYNAMICLOADER_H__
#define _WX_DYNAMICLOADER_H__
#ifdef __GNUG__
#pragma interface "dynload.h"
#endif
// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------
#include "wx/defs.h"
#if wxUSE_DYNAMIC_LOADER
#include "wx/hash.h"
#include "wx/module.h"
// Ugh, I'd much rather this was typesafe, but no time
// to rewrite wxHashTable right now..
typedef wxHashTable wxDLManifest;
typedef wxHashTable wxDLImports;
// ----------------------------------------------------------------------------
// conditional compilation
// ----------------------------------------------------------------------------
// Note: WXPM/EMX has to be tested first, since we want to use
// native version, even if configure detected presence of DLOPEN.
#if defined(__WXPM__) || defined(__EMX__)
#define INCL_DOS
#include <os2.h>
typedef HMODULE wxDllType;
#elif defined(HAVE_DLOPEN)
#include <dlfcn.h>
typedef void *wxDllType;
#elif defined(HAVE_SHL_LOAD)
#include <dl.h>
typedef shl_t wxDllType;
#elif defined(__WINDOWS__)
#include <windows.h> // needed to get HMODULE
typedef HMODULE wxDllType;
#elif defined(__DARWIN__)
typedef void *wxDllType;
#elif defined(__WXMAC__)
typedef CFragConnectionID wxDllType;
#else
#error "wxLibrary can't be compiled on this platform, sorry."
#endif
// LoadLibrary is defined in windows.h as LoadLibraryA, but wxDllLoader
// method should be called LoadLibrary, not LoadLibraryA or LoadLibraryW!
#if defined(__WIN32__) && defined(LoadLibrary)
# include "wx/msw/winundef.h"
#endif
// ---------------------------------------------------------------------------
// wxDllLoader
// ---------------------------------------------------------------------------
// Cross platform wrapper for dlopen and friends.
// There are no instances of this class, it simply
// serves as a namespace for its static member functions.
class WXDLLEXPORT wxDllLoader
{
public:
// libname may be either the full path to the file or just the filename
// in which case the library is searched for in all standard locations.
// The platform specific library extension is automatically appended.
static wxDllType Load(const wxString& name);
// The same as Load, except 'name' is searched for without modification.
static wxDllType LoadLibrary(const wxString& name);
static void UnloadLibrary(wxDllType dll);
// return a valid handle for the main program itself or NULL if
// back linking is not supported by the current platform (e.g. Win32)
static wxDllType GetProgramHandle();
// resolve a symbol in a loaded DLL, such as a variable or function
// name. dllHandle is a handle previously returned by LoadLibrary(),
// symbol is the (possibly mangled) name of the symbol.
// (use extern "C" to export unmangled names)
//
// Since it is perfectly valid for the returned symbol to actually be
// NULL, that is not always indication of an error. Pass and test the
// parameter 'success' for a true indication of success or failure to
// load the symbol.
//
// Returns a pointer to the symbol on success.
static void *GetSymbol(wxDllType dllHandle, const wxString &name, bool *success = 0);
// return the platform standard DLL extension (with leading dot)
static const wxString &GetDllExt() { return ms_dllext; }
private:
wxDllLoader(); // forbid construction of objects
static const wxString ms_dllext; // Platform specific shared lib suffix.
};
// ---------------------------------------------------------------------------
// wxDynamicLibrary
// ---------------------------------------------------------------------------
class wxDLManifestEntry
{
public:
static wxDLImports ms_classes; // Static hash of all imported classes.
wxDLManifestEntry( const wxString &libname );
~wxDLManifestEntry();
wxDLManifestEntry *RefLib() { ++m_linkcount; return this; }
bool UnrefLib();
// These two are called by the PluginSentinel on (PLUGGABLE) object
// creation/destruction. There is usually no reason for the user to
// call them directly. We have to separate this from the link count,
// since the two are not interchangeable.
// FIXME: for even better debugging PluginSentinel should register
// the name of the class created too, then we can state
// exactly which object was not destroyed which may be
// difficult to find otherwise. Also this code should
// probably only be active in DEBUG mode, but let's just
// get it right first.
void RefObj() { ++m_objcount; }
void UnrefObj()
{
wxASSERT_MSG( m_objcount > 0, _T("Too many objects deleted??") );
--m_objcount;
}
bool IsLoaded() const { return m_linkcount > 0; }
wxDllType GetLinkHandle() const { return m_handle; }
wxDllType GetProgramHandle() const { return wxDllLoader::GetProgramHandle(); }
void *GetSymbol(const wxString &symbol, bool *success = 0)
{
return wxDllLoader::GetSymbol( m_handle, symbol, success );
}
private:
// Order of these three *is* important, do not change it
wxClassInfo *m_before; // sm_first before loading this lib
wxDllType m_handle; // Handle from dlopen.
wxClassInfo *m_after; // ..and after.
size_t m_linkcount; // Ref count of library link calls
size_t m_objcount; // ..and (pluggable) object instantiations.
wxModuleList m_wxmodules; // any wxModules that we initialised.
void UpdateClassInfo(); // Update the wxClassInfo table
void RestoreClassInfo(); // Restore the original wxClassInfo state.
void RegisterModules(); // Init any wxModules in the lib.
void UnregisterModules(); // Cleanup any wxModules we installed.
DECLARE_NO_COPY_CLASS(wxDLManifestEntry)
};
class WXDLLEXPORT wxDynamicLibrary
{
public:
// Static accessors.
static wxDLManifestEntry *Link(const wxString &libname);
static bool Unlink(const wxString &libname);
// Instance methods.
wxDynamicLibrary(const wxString &libname);
~wxDynamicLibrary();
bool IsLoaded() const { return m_entry && m_entry->IsLoaded(); }
void *GetSymbol(const wxString &symbol, bool *success = 0)
{
return m_entry->GetSymbol( symbol, success );
}
private:
static wxDLManifest ms_manifest; // Static hash of loaded libs.
wxDLManifestEntry *m_entry; // Cache our entry in the manifest.
// We could allow this class to be copied if we really
// wanted to, but not without modification.
DECLARE_NO_COPY_CLASS(wxDynamicLibrary)
};
#endif // wxUSE_DYNAMIC_LOADER
#endif // _WX_DYNAMICLOADER_H__
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