/************************************************************************* ** DLLoader.hpp ** ** ** ** This file is part of dvisvgm -- a fast DVI to SVG converter ** ** Copyright (C) 2005-2024 Martin Gieseking <martin.gieseking@uos.de> ** ** ** ** This program is free software; you can redistribute it and/or ** ** modify it under the terms of the GNU General Public License as ** ** published by the Free Software Foundation; either version 3 of ** ** the License, or (at your option) any later version. ** ** ** ** This program is distributed in the hope that it will be useful, but ** ** WITHOUT ANY WARRANTY; without even the implied warranty of ** ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ** ** GNU General Public License for more details. ** ** ** ** You should have received a copy of the GNU General Public License ** ** along with this program; if not, see <http://www.gnu.org/licenses/>. ** *************************************************************************/ #ifndef DLLOADER_HPP #define DLLOADER_HPP #include <string> #ifdef _WIN32 #include "windows.hpp" #else #include <dlfcn.h> #endif class DLLoader { public: DLLoader () =delete; explicit DLLoader (const std::string &dlname); DLLoader (DLLoader &&loader) =default; virtual ~DLLoader () {closeLibrary();} bool loaded () const {return _handle != nullptr;} bool loadLibrary (const std::string &dlname); protected: template <typename T> T loadSymbol (const char *name) const; void closeLibrary (); private: #ifdef _WIN32 HINSTANCE _handle; #else void *_handle; #endif }; /** Loads a function or variable from the dynamic/shared library. * @param[in] name name of function/variable to load * @return pointer to loaded symbol, or 0 if the symbol could not be loaded */ template <typename T> T DLLoader::loadSymbol (const char *name) const { if (_handle) { #ifdef _WIN32 return reinterpret_cast<T>(GetProcAddress(_handle, name)); #else return reinterpret_cast<T>(dlsym(_handle, name)); #endif } return nullptr; } #define LOAD_SYMBOL(sym) loadSymbol<decltype(&sym)>(#sym) #endif