shithub: cstory

ref: d9929a8e1fb5f2ae8c5532aea16c8d3dc04bd9a0
dir: /external/SDL2/test/testloadso.c/

/*
  Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely.
*/

/* Test program to test dynamic loading with the loadso subsystem.
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "SDL.h"

typedef int (*fntype) (const char *);

int
main(int argc, char *argv[])
{
    int retval = 0;
    int hello = 0;
    const char *libname = NULL;
    const char *symname = NULL;
    void *lib = NULL;
    fntype fn = NULL;

    if (argc != 3) {
        const char *app = argv[0];
        SDL_Log("USAGE: %s <library> <functionname>\n", app);
        SDL_Log("       %s --hello <lib with puts()>\n", app);
        return 1;
    }

    /* Initialize SDL */
    if (SDL_Init(0) < 0) {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize SDL: %s\n", SDL_GetError());
        return 2;
    }

    if (strcmp(argv[1], "--hello") == 0) {
        hello = 1;
        libname = argv[2];
        symname = "puts";
    } else {
        libname = argv[1];
        symname = argv[2];
    }

    lib = SDL_LoadObject(libname);
    if (lib == NULL) {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "SDL_LoadObject('%s') failed: %s\n",
                libname, SDL_GetError());
        retval = 3;
    } else {
        fn = (fntype) SDL_LoadFunction(lib, symname);
        if (fn == NULL) {
            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "SDL_LoadFunction('%s') failed: %s\n",
                    symname, SDL_GetError());
            retval = 4;
        } else {
            SDL_Log("Found %s in %s at %p\n", symname, libname, fn);
            if (hello) {
                SDL_Log("Calling function...\n");
                fflush(stdout);
                fn("     HELLO, WORLD!\n");
                SDL_Log("...apparently, we survived.  :)\n");
                SDL_Log("Unloading library...\n");
                fflush(stdout);
            }
        }
        SDL_UnloadObject(lib);
    }
    SDL_Quit();
    return retval;
}