1 /* +------------------------------------+
2 * | Inspire Internet Relay Chat Daemon |
3 * +------------------------------------+
5 * InspIRCd: (C) 2002-2009 InspIRCd Development Team
6 * See: http://wiki.inspircd.org/Credits
8 * This program is free but copyrighted software; see
9 * the file COPYING for details.
11 * ---------------------------------------------------
17 /** The DLLManager class is able to load a module file by filename,
18 * and locate its init_module symbol.
20 class CoreExport DLLManager : public classbase
24 /** The last error string, or NULL
29 /** This constructor loads the module using dlopen()
30 * @param fname The filename to load. This should be within
33 DLLManager(const char *fname);
34 virtual ~DLLManager();
36 /** Get a symbol using dynamic linking.
37 * @param v A function pointer, pointing at an init_module function
38 * @param sym_name The symbol name to find, usually "init_module"
39 * @return true if the symbol can be found, also the symbol will be put into v.
41 bool GetSymbol(void **v, const char *sym_name);
43 /** Get the last error from dlopen() or dlsym().
44 * @return The last error string, or NULL if no error has occured.
46 const char* LastError()
51 /** The module handle.
52 * This is OS dependent, on POSIX platforms it is a pointer to a function
53 * pointer (yes, really!) and on windows it is a library handle.
58 class CoreExport LoadModuleException : public CoreException
61 /** This constructor can be used to specify an error message before throwing.
63 LoadModuleException(const std::string &message)
64 : CoreException(message, "the core")
68 /** This destructor solves world hunger, cancels the world debt, and causes the world to end.
69 * Actually no, it does nothing. Never mind.
72 virtual ~LoadModuleException() throw() {};
75 class CoreExport FindSymbolException : public CoreException
78 /** This constructor can be used to specify an error message before throwing.
80 FindSymbolException(const std::string &message)
81 : CoreException(message, "the core")
85 /** This destructor solves world hunger, cancels the world debt, and causes the world to end.
86 * Actually no, it does nothing. Never mind.
89 virtual ~FindSymbolException() throw() {};
92 /** This is the highest-level class of the DLLFactory system used to load InspIRCd modules and commands.
93 * All the dirty mucking around with dl*() is done by DLLManager, all this does it put a pretty shell on
94 * it and make it nice to use to load modules and core commands. This class is quite specialised for these
95 * two uses and it may not be useful more generally -- use DLLManager directly for that.
97 template <typename ReturnType> class CoreExport DLLFactory : public DLLManager
100 /** This typedef represents the init_* function within each module or command.
101 * The init_module function is the only exported extern "C" declaration
102 * in any module file. In a cmd_*.cpp file the equivilant is init_command
104 typedef ReturnType * (initfunctype) ();
106 /** Pointer to the init function.
108 initfunctype* init_func;
111 /** Default constructor.
112 * This constructor passes its paramerers down through DLLFactoryBase and then DLLManager
113 * to load the module, then calls the factory function to retrieve a pointer to a ModuleFactory
114 * class. It is then down to the core to call the ModuleFactory::CreateModule() method and
115 * receive a Module* which it can insert into its module lists.
117 DLLFactory(const char *fname, const char *func_name)
118 : DLLManager(fname), init_func(NULL)
120 const char* error = LastError();
124 if(!GetSymbol((void **)&init_func, func_name))
126 throw FindSymbolException("Missing " + std::string(func_name) + "() entrypoint!");
131 throw LoadModuleException(error);
135 /** Calls the 'init_module' C exported function within a module, which
136 * returns a pointer to a Module derived object.
138 ReturnType* CallInit()
150 /** The destructor deletes the ModuleFactory pointer.