Questions on the harness example

[symexec]

The harness example included in the README is as follows:

#include <stdio.h>
...
typedef int (__stdcall *IDP_Init_func_t)(int);
typedef int (__stdcall *IDP_GetPlugInInfo_func_t)(int);
...

void fuzz_me(char* filename){

    IDP_Init_func_t IDP_Init_func;
    IDP_GetPlugInInfo_func_t IDP_GetPlugInInfo_func;
...

    /* Harness function #0 */
    int* c0_a0 = (int*) calloc (4096, sizeof(int));    
    LOAD_FUNC(dlllib, IDP_Init);
    int IDP_Init_ret = IDP_Init_func(&c0_a0);
    dbg_printf("IDP_Init, ret = %d\n", IDP_Init_ret); 
    
    /* Harness function #1 */
    int* c1_a0 = (int*) calloc (4096, sizeof(int));    
    LOAD_FUNC(dlllib, IDP_GetPlugInInfo);
    int IDP_GetPlugInInfo_ret = IDP_GetPlugInInfo_func(&c1_a0);
    dbg_printf("IDP_GetPlugInInfo, ret = %d\n", IDP_GetPlugInInfo_ret); 

...
    /* Harness function #66 */
    int* c66_a0 = (int*) calloc (4096, sizeof(int));    
    LOAD_FUNC(dlllib, IDP_CloseImage);
    int IDP_CloseImage_ret = IDP_CloseImage_func(&c66_a0);
    dbg_printf("IDP_CloseImage, ret = %d\n", IDP_CloseImage_ret); 

}


int main(int argc, char ** argv)
{
    if (argc < 2) {
        printf("Usage %s: <input file>\n", argv[0]);
        printf("  e.g., harness.exe input\n");
        exit(1);
    }

    dlllib = LoadLibraryA("%s");
    if (dlllib == NULL){
        dbg_printf("failed to load library, gle = %d\n", GetLastError());
        exit(1);
    }

    char * filename = argv[1];    
    fuzz_me(filename);    
    return 0;
}

Questions:

• The LoadLibraryA call does not accept any DLL name as input. Then how would the corresponding library be loaed?
• The filename passed to the fuzz_me method in never read. Then how would it feed input to the API calls? The broader question is how the input read from the file flows to the APIs.
• According to the function signature, IDP_Init method accepts an int argument. However, a pointer to an integer array was passed during invocation. Is that intended?
• According to the README, afl-fuzz expects a DLL as harness (-harness harness.dll), while the example above is likely to generate a standalone executable that does not even conform the harness API. Can you explain?