undefined reference when compiling the driver with shared library file

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                          I made a simple memory manager, and I'm trying to compile it using a shared library in the driver.

The shared library files itself compiles fine, however when I compiled the driver by calling the functions in the shared library with my memory manager, it shows me the screenshot below:




Here is my code for the shared.c:

    /* conveniences for casting and declarations */
    typedef block_info* (*MM_CREATE)(size_t, MMPolicy);
    typedef void* (*MM_ALLOCATE)(block_info *, size_t, char *);
    typedef int (*MM_DEALLOCATE)(block_info *, void *);
    typedef void (*MM_DESTROY)(block_info *);

    /* Function pointers retrieved from the shared library */
    typedef struct LibraryFunctions
    {
       MM_CREATE create;
       MM_DESTROY destroy;
       MM_ALLOCATE allocate;
       MM_DEALLOCATE deallocate;
    }LibraryFunctions;

    /* Loads a shared library and returns a pointer to it in libhandle */

    /* Returns SUCCESS, if it successful, otherwise, FAILURE           */
    int load_library(const char *libname, void **libhandle)
    {
    
    *libhandle = dlopen(*libhandle, RTLD_LAZY);
    
    if(!(*libhandle))
    {
        return FAILURE;
    }
    else
    {
        return SUCCESS;
    }
    
    return *libname;
    }
    int get_functions(void *libhandle, 
                   LibraryFunctions *functions, 
                   const char **fn_names)
    {
    functions->create = (MM_CREATE)(intptr_t)dlsym(libhandle, *fn_names);
    
    if(!functions->create)
    {
        return FAILURE;
    }
                     
    functions->destroy = (MM_DESTROY)(intptr_t)dlsym(libhandle, *fn_names);
    
    if(!functions->destroy)
    {
        return FAILURE;
    }
    
    functions->allocate = (MM_ALLOCATE)(intptr_t)dlsym(libhandle, *fn_names);
    
    if(!functions->allocate)
    {
        return FAILURE;
    }
    
    functions->deallocate = (MM_DEALLOCATE)(intptr_t)dlsym(libhandle, *fn_names);
    
    if(!functions->deallocate)
    {
        return FAILURE;
    }
    
    return SUCCESS;
}
Here is part of the driver code to call the shared library:

    void setup(void)
    {
      const char *fn_names[] = {"mm_create", "mm_destroy", "mm_allocate",   "mm_deallocate"};
      LibraryFunctions funs;
      int error;

      error = load_library("./libmemmgr.so", &gLib);
      if (error == FAILURE)
      {
        printf("load_library failed! %s\n", dlerror());
        exit(-1);
      }

      error = get_functions(gLib, &funs, fn_names);
      if (error == FAILURE)
      {
        printf("get_functions failed! %s\n", dlerror());
        exit(-1);
      }

      mmlib_create = funs.create;
      mmlib_destroy = funs.destroy;
      mmlib_allocate = funs.allocate;
      mmlib_deallocate = funs.deallocate;
   }

    void teardown(void)
    {
      dlclose(gLib);
    }

I'm not sure what is causing the errors.
 
edit: So I managed to run the exe file but I failed on "get_functions". Are there any problems with my get_functions?
                        
Asked by TommyLan (35 rep)
Jul 9, 2015, 10:31 PM
Last activity: Nov 7, 2024, 12:14 AM
undefined reference when compiling the driver with shared library file

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