shithub: cstory

ref: 5cc1d5ac018d4c00f11cb31a9ab6fdc6a0a4b3f4
dir: /external/SDL2/test/testloadso.c/

/*
  Copyright (C) 1997-2019 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;
}