/////////////////////////////////////////////////////////////////////////////
// Name: wx/dynlib.h
// Purpose: Dynamic library loading classes
// Author: Guilhem Lavaux, Vadim Zeitlin, Vaclav Slavik
// Modified by:
// Created: 20/07/98
// Copyright: (c) 1998 Guilhem Lavaux
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#ifndef _WX_DYNLIB_H__
#define _WX_DYNLIB_H__
#include "wx/defs.h"
#if wxUSE_DYNLIB_CLASS
#include "wx/string.h"
#include "wx/dynarray.h"
class WXDLLIMPEXP_FWD_BASE wxDynamicLibraryDetailsCreator;
// ----------------------------------------------------------------------------
// conditional compilation
// ----------------------------------------------------------------------------
#if defined(__WINDOWS__)
typedef WXHMODULE wxDllType;
#elif defined(HAVE_DLOPEN)
#include <dlfcn.h>
typedef void *wxDllType;
#elif defined(__WXMAC__)
#include <CodeFragments.h>
typedef CFragConnectionID wxDllType;
#else
#error "Dynamic Loading classes can't be compiled on this platform, sorry."
#endif
// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------
enum wxDLFlags
{
wxDL_LAZY = 0x00000001, // resolve undefined symbols at first use
// (only works on some Unix versions)
wxDL_NOW = 0x00000002, // resolve undefined symbols on load
// (default, always the case under Win32)
wxDL_GLOBAL = 0x00000004, // export extern symbols to subsequently
// loaded libs.
wxDL_VERBATIM = 0x00000008, // attempt to load the supplied library
// name without appending the usual dll
// filename extension.
// this flag is obsolete, don't use
wxDL_NOSHARE = 0x00000010, // load new DLL, don't reuse already loaded
// (only for wxPluginManager)
wxDL_QUIET = 0x00000020, // don't log an error if failed to load
// this flag is dangerous, for internal use of wxMSW only, don't use at all
// and especially don't use directly, use wxLoadedDLL instead if you really
// do need it
wxDL_GET_LOADED = 0x00000040, // Win32 only: return handle of already
// loaded DLL or NULL otherwise; Unload()
// should not be called so don't forget to
// Detach() if you use this function
wxDL_DEFAULT = wxDL_NOW // default flags correspond to Win32
};
enum wxDynamicLibraryCategory
{
wxDL_LIBRARY, // standard library
wxDL_MODULE // loadable module/plugin
};
enum wxPluginCategory
{
wxDL_PLUGIN_GUI, // plugin that uses GUI classes
wxDL_PLUGIN_BASE // wxBase-only plugin
};
// ----------------------------------------------------------------------------
// macros
// ----------------------------------------------------------------------------
// when loading a function from a DLL you always have to cast the returned
// "void *" pointer to the correct type and, even more annoyingly, you have to
// repeat this type twice if you want to declare and define a function pointer
// all in one line
//
// this macro makes this slightly less painful by allowing you to specify the
// type only once, as the first parameter, and creating a variable of this type
// called "pfn<name>" initialized with the "name" from the "dynlib"
#define wxDYNLIB_FUNCTION(type, name, dynlib) \
type pfn ## name = (type)(dynlib).GetSymbol(wxT(#name))
// a more convenient function replacing wxDYNLIB_FUNCTION above
//
// it uses the convention that the type of the function is its name suffixed
// with "_t" but it doesn't define a variable but just assigns the loaded value
// to it and also allows to pass it the prefix to be used instead of hardcoding
// "pfn" (the prefix can be "m_" or "gs_pfn" or whatever)
//
// notice that this function doesn't generate error messages if the symbol
// couldn't be loaded, the caller should generate the appropriate message
#define wxDL_INIT_FUNC(pfx, name, dynlib) \
pfx ## name = (name ## _t)(dynlib).RawGetSymbol(#name)
#ifdef __WINDOWS__
// same as wxDL_INIT_FUNC() but appends 'A' or 'W' to the function name, see
// wxDynamicLibrary::GetSymbolAorW()
#define wxDL_INIT_FUNC_AW(pfx, name, dynlib) \
pfx ## name = (name ## _t)(dynlib).GetSymbolAorW(#name)
#endif // __WINDOWS__
// the following macros can be used to redirect a whole library to a class and
// check at run-time if the library is present and contains all required
// methods
//
// notice that they are supposed to be used inside a class which has "m_ok"
// member variable indicating if the library had been successfully loaded
// helper macros constructing the name of the variable storing the function
// pointer and the name of its type from the function name
#define wxDL_METHOD_NAME(name) m_pfn ## name
#define wxDL_METHOD_TYPE(name) name ## _t
// parameters are:
// - rettype: return type of the function, e.g. "int"
// - name: name of the function, e.g. "foo"
// - args: function signature in parentheses, e.g. "(int x, int y)"
// - argnames: the names of the parameters in parentheses, e.g. "(x, y)"
// - defret: the value to return if the library wasn't successfully loaded
#define wxDL_METHOD_DEFINE( rettype, name, args, argnames, defret ) \
typedef rettype (* wxDL_METHOD_TYPE(name)) args ; \
wxDL_METHOD_TYPE(name) wxDL_METHOD_NAME(name); \
rettype name args \
{ return m_ok ? wxDL_METHOD_NAME(name) argnames : defret; }
#define wxDL_VOIDMETHOD_DEFINE( name, args, argnames ) \
typedef void (* wxDL_METHOD_TYPE(name)) args ; \
wxDL_METHOD_TYPE(name) wxDL_METHOD_NAME(name); \
void name args \
{ if ( m_ok ) wxDL_METHOD_NAME(name) argnames ; }
#define wxDL_METHOD_LOAD(lib, name) \
wxDL_METHOD_NAME(name) = \
(wxDL_METHOD_TYPE(name)) lib.GetSymbol(#name, &m_ok); \
if ( !m_ok ) return false
// ----------------------------------------------------------------------------
// wxDynamicLibraryDetails: contains details about a loaded wxDynamicLibrary
// ----------------------------------------------------------------------------
class WXDLLIMPEXP_BASE wxDynamicLibraryDetails
{
public:
// ctor, normally never used as these objects are only created by
// wxDynamicLibrary::ListLoaded()
wxDynamicLibraryDetails() { m_address = NULL; m_length = 0; }
// get the (base) name
wxString GetName() const { return m_name; }
// get the full path of this object
wxString GetPath() const { return m_path; }
// get the load address and the extent, return true if this information is
// available
bool GetAddress(void **addr, size_t *len) const
{
if ( !m_address )
return false;
if ( addr )
*addr = m_address;
if ( len )
*len = m_length;
return true;
}
// return the version of the DLL (may be empty if no version info)
wxString GetVersion() const
{
return m_version;
}
private:
wxString m_name,
m_path,
m_version;
void *m_address;
size_t m_length;
friend class wxDynamicLibraryDetailsCreator;
};
WX_DECLARE_USER_EXPORTED_OBJARRAY(wxDynamicLibraryDetails,
wxDynamicLibraryDetailsArray,
WXDLLIMPEXP_BASE);
// ----------------------------------------------------------------------------
// wxDynamicLibrary: represents a handle to a DLL/shared object
// ----------------------------------------------------------------------------
class WXDLLIMPEXP_BASE wxDynamicLibrary
{
public:
// 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();
// return the platform standard DLL extension (with leading dot)
static wxString GetDllExt(wxDynamicLibraryCategory cat = wxDL_LIBRARY);
wxDynamicLibrary() : m_handle(NULL) { }
wxDynamicLibrary(const wxString& libname, int flags = wxDL_DEFAULT)
: m_handle(NULL)
{
Load(libname, flags);
}
// NOTE: this class is (deliberately) not virtual, do not attempt
// to use it polymorphically.
~wxDynamicLibrary() { Unload(); }
// return true if the library was loaded successfully
bool IsLoaded() const { return m_handle != NULL; }
// load the library with the given name (full or not), return true if ok
bool Load(const wxString& libname, int flags = wxDL_DEFAULT);
// raw function for loading dynamic libs: always behaves as if
// wxDL_VERBATIM were specified and doesn't log error message if the
// library couldn't be loaded but simply returns NULL
static wxDllType RawLoad(const wxString& libname, int flags = wxDL_DEFAULT);
// attach to an existing handle
void Attach(wxDllType h) { Unload(); m_handle = h; }
// detach the library object from its handle, i.e. prevent the object from
// unloading the library in its dtor -- the caller is now responsible for
// doing this
wxDllType Detach() { wxDllType h = m_handle; m_handle = NULL; return h; }
// unload the given library handle (presumably returned by Detach() before)
static void Unload(wxDllType handle);
// unload the library, also done automatically in dtor
void Unload() { if ( IsLoaded() ) { Unload(m_handle); m_handle = NULL; } }
// Return the raw handle from dlopen and friends.
wxDllType GetLibHandle() const { return m_handle; }
// check if the given symbol is present in the library, useful to verify if
// a loadable module is our plugin, for example, without provoking error
// messages from GetSymbol()
bool HasSymbol(const wxString& name) const
{
bool ok;
DoGetSymbol(name, &ok);
return ok;
}
// resolve a symbol in a loaded DLL, such as a variable or function name.
// 'name' 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, or NULL if an error occurred
// or the symbol wasn't found.
void *GetSymbol(const wxString& name, bool *success = NULL) const;
// low-level version of GetSymbol()
static void *RawGetSymbol(wxDllType handle, const wxString& name);
void *RawGetSymbol(const wxString& name) const
{
return RawGetSymbol(m_handle, name);
}
#ifdef __WINDOWS__
// this function is useful for loading functions from the standard Windows
// DLLs: such functions have an 'A' (in ANSI build) or 'W' (in Unicode, or
// wide character build) suffix if they take string parameters
static void *RawGetSymbolAorW(wxDllType handle, const wxString& name)
{
return RawGetSymbol
(
handle,
name +
#if wxUSE_UNICODE
L'W'
#else
'A'
#endif
);
}
void *GetSymbolAorW(const wxString& name) const
{
return RawGetSymbolAorW(m_handle, name);
}
#endif // __WINDOWS__
// return all modules/shared libraries in the address space of this process
//
// returns an empty array if not implemented or an error occurred
static wxDynamicLibraryDetailsArray ListLoaded();
// return platform-specific name of dynamic library with proper extension
// and prefix (e.g. "foo.dll" on Windows or "libfoo.so" on Linux)
static wxString CanonicalizeName(const wxString& name,
wxDynamicLibraryCategory cat = wxDL_LIBRARY);
// return name of wxWidgets plugin (adds compiler and version info
// to the filename):
static wxString
CanonicalizePluginName(const wxString& name,
wxPluginCategory cat = wxDL_PLUGIN_GUI);
// return plugin directory on platforms where it makes sense and empty
// string on others:
static wxString GetPluginsDirectory();
// Return the load address of the module containing the given address or
// NULL if not found.
//
// If path output parameter is non-NULL, fill it with the full path to this
// module disk file on success.
static void* GetModuleFromAddress(const void* addr, wxString* path = NULL);
#ifdef __WINDOWS__
// return the handle (HMODULE/HINSTANCE) of the DLL with the given name
// and/or containing the specified address: for XP and later systems only
// the address is used and the name is ignored but for the previous systems
// only the name (which may be either a full path to the DLL or just its
// base name, possibly even without extension) is used
//
// the returned handle reference count is not incremented so it doesn't
// need to be freed using FreeLibrary() but it also means that it can
// become invalid if the DLL is unloaded
static WXHMODULE MSWGetModuleHandle(const wxString& name, void *addr);
#endif // __WINDOWS__
protected:
// common part of GetSymbol() and HasSymbol()
void* DoGetSymbol(const wxString& name, bool* success = NULL) const;
// log the error after an OS dynamic library function failure
static void ReportError(const wxString& msg,
const wxString& name = wxString());
// the handle to DLL or NULL
wxDllType m_handle;
// no copy ctor/assignment operators (or we'd try to unload the library
// twice)
wxDECLARE_NO_COPY_CLASS(wxDynamicLibrary);
};
#ifdef __WINDOWS__
// ----------------------------------------------------------------------------
// wxLoadedDLL is a MSW-only internal helper class allowing to dynamically bind
// to a DLL already loaded into the project address space
// ----------------------------------------------------------------------------
class wxLoadedDLL : public wxDynamicLibrary
{
public:
wxLoadedDLL(const wxString& dllname)
: wxDynamicLibrary(dllname, wxDL_GET_LOADED | wxDL_VERBATIM | wxDL_QUIET)
{
}
~wxLoadedDLL()
{
Detach();
}
};
#endif // __WINDOWS__
// ----------------------------------------------------------------------------
// Interesting defines
// ----------------------------------------------------------------------------
#define WXDLL_ENTRY_FUNCTION() \
extern "C" WXEXPORT const wxClassInfo *wxGetClassFirst(); \
const wxClassInfo *wxGetClassFirst() { \
return wxClassInfo::GetFirst(); \
}
#endif // wxUSE_DYNLIB_CLASS
#endif // _WX_DYNLIB_H__
