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Dynamic_Loading.h
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//Dynamic_Loading.h
#ifndef DYNAMIC_LOADING_H_TRANSPORT
#define DYNAMIC_LOADING_H_TRANSPORT
#include <iostream>
#include <string>
#include "./Misc.h" //Various utilities. FUNCINFO, FUNCERR, etc..
#include "./Dynamic_Loading.h"
// Correct usage syntax is:
//
//funcp = (int (*)(int)) dlsym(...);
//
// or
//
//funcp = (int (*)(int)) load_item_from_library(....);
//
// ala:
// "The cast on the left-hand side is functionally useless and actually
// creates a second problem (the result of a cast is not an lvalue).
// (Note that in C++ you can't use a reinterpret_cast, since that's
// explicitly forbidden for conversion between function pointers and data
// pointers; you must use the old-style C cast.) "
// from http://unix.derkeiler.com/Newsgroups/comp.unix.programmer/2004-05/0241.html.
//
void * load_library(std::string library_name);
void close_library(void *loaded_library);
void * load_item_from_library(void *loaded_library, std::string item_name);
bool check_for_item_in_library(void *loaded_library, std::string item_name);
//----------------------------------------------------------------------------------------------------
//------------------------------------------ Helper Macros -------------------------------------------
//----------------------------------------------------------------------------------------------------
//
// FIXME FIXME FIXME WIP FIXME FIXME FIXME
//
// See http://unix.derkeiler.com/Newsgroups/comp.unix.programmer/2004-05/0241.html :(
// (and the previous message in the thread)
//
//This macro reduces the -pedantic errors of compiling code that looks like this:
// |-----> int (*funcp)(int, std::string); //Pointer to function with int and std::string arguments.
// (void *) funcp = dlsym(handle, symbol);
// which produces, using gcc -pedantic , warnings:
// |-----> "ANSI C forbids the use of cast expressions as lvalues"
// or |
// |-----> "warning: ISO C++ forbids casting between pointer-to-function and pointer-to-object"
// to the warning-free variant:
// |-----> int (*funcp)(int, std::string); //Pointer to function with int and std::string arguments.
// *(void **) (&funcp) = dlsym(handle, symbol);
//
// Usage is NOT required, and warnings will only show up with the -pedantic option (gcc 4.6.2.)
// ____Usage____ is:
// turn:
// |-----> FUNCTION_init_explicit_seed PRNG_seed = reinterpret_cast<FUNCTION_init_explicit_seed>(load_item_from_library(loaded_library, "init_explicit_seed") );
// into:
// |-----> FUNCTION_init_explicit_seed DYN_PED( PRNG_seed) = reinterpret_cast<FUNCTION_init_explicit_seed>(load_item_from_library(loaded_library, "init_explicit_seed") );
//
// and say goodbye to those nasty pedantic warnings :)
//#ifndef DYN_PED
// #define DYN_PED ( x ) *(void **)(&(#x))
//
// typedef void sillywrapperforvoid;
// #define DYN_PED ( x ) *(sillywrapperforvoid **)&
//
// typedef *(void **)& DYN_PED
//
// #define DYN_PED
//#endif
#endif