#define _GNU_SOURCE         /* See feature_test_macros(7) */

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <string.h>

#define DEBUG

#ifdef DEBUG
#define dprintf(...)                                            \
    do {                                                        \
	char msg[1024];                                         \
	sprintf(msg, __VA_ARGS__);                              \
	fprintf(stderr, "%s,%s", __FUNCTION__, msg);            \
    } while (0);
#define eprintf(...)                                            \
    do {                                                        \
	char msg[1024];                                         \
	sprintf(msg, __VA_ARGS__);                              \
	fprintf(stderr, "%s,%s", __FUNCTION__, msg);            \
    } while (0);
#else
#define dprintf(...) do {  } while (0)
#define eprintf(...) do {  } while (0)
#endif

#define CHKANDJUMP(cond, err, ...)                                      \
    do {                                                                \
		if(cond) {                                                      \
			eprintf(__VA_ARGS__);                                       \
			ret = err;                                                  \
			goto fn_fail;                                               \
		}                                                               \
    } while(0)

int sz_anon[] = {
	4 * (1ULL<<10),
	2 * (1ULL<<20),
	1 * (1ULL<<30),
	134217728};

#define SZ_INDEX 0
#define NUM_AREAS 1

int main(int argc, char** argv) {
	int i;
	void* mem;
	void* newmem;
	int ret = 0;

	mem = mmap(0, sz_anon[SZ_INDEX], PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
	CHKANDJUMP(mem == MAP_FAILED, 255, "mmap failed\n");
	*((unsigned long*)mem) = 0x123456789abcdef0;

	newmem = mremap(mem, sz_anon[SZ_INDEX], sz_anon[SZ_INDEX + 1], MREMAP_MAYMOVE);
	CHKANDJUMP(newmem == MAP_FAILED, 255, "mmap failed\n");
	*((unsigned long*)mem) = 0xbeefbeefbeefbeef;

	munmap(newmem, sz_anon[SZ_INDEX + 1]);
	
 fn_exit:
	return ret;
 fn_fail:
	goto fn_exit;
}