Simplest interpreter for C

#include <memory.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define int long long // work with 64bit target

int token;
int *text, *old_text, *stack;
char *data;

int *pc, *bp, *sp, ax, cycle;

enum {
  LEA,
  IMM,
  JMP,
  CALL,
  JZ,
  JNZ,
  ENT,
  ADJ,
  LEV,
  LI,
  LC,
  SI,
  SC,
  PUSH,
  OR,
  XOR,
  AND,
  EQ,
  NE,
  LT,
  GT,
  LE,
  GE,
  SHL,
  SHR,
  ADD,
  SUB,
  MUL,
  DIV,
  MOD,
  OPEN,
  READ,
  CLOS,
  PRTF,
  MALC,
  MSET,
  MCMP,
  EXIT
};

void next() {
  token = *src++;
  return;
}

void expression(int level) {}

void program() {
  next();
  while (token > 0) {
    printf("Token is: %c\n", token);
    next();
  }
}

int eval() {
  int op, *tmp;

  while (1) {
    op = *pc++;
    if (op == IMM) {
      ax = *pc++;
    } else if (op == LC) {
      ax = *(char *)ax;
    } else if (op == LI) {
      ax = *(int *)ax;
    } else if (op == SC) {
      ax = *(char *)*sp++ = ax;
    } else if (op == SI) {
      *(int *)*sp++ = ax;
    } else if (op == PUSH) {
      *--sp = ax;
    } else if (op == JMP) {
      pc = (int *)*pc;
    } else if (op == JZ) {
      pc = ax ? pc + 1 : (int *)*pc;
    } else if (op == JNZ) {
      pc = ax ? (int *)*pc : pc + 1;
    } else if (op == CALL) {
      *--sp = (int)(pc + 1);
      pc = (int *)*pc;
    }
    else if (op == ENT){
        *--sp = (int)bp;
        bp = sp;
        sp = sp - *pc++;
    }
    else if (op == ADJ){
       sp = sp + *pc++;
    }
    else if (op == LEV){
        sp = bp;
        bp = (int *)*sp++;
        pc = (int *)*sp++;
    }

    // Mathematical actions
    else if (op == OR)  ax = *sp++ | ax;
    else if (op == XOR) ax = *sp++ ^ ax;
    else if (op == AND) ax = *sp++ & ax;
    else if (op == EQ)  ax = *sp++ == ax;
    else if (op == NE)  ax = *sp++ != ax;
    else if (op == LT)  ax = *sp++ < ax;
    else if (op == LE)  ax = *sp++ <= ax;
    else if (op == GT)  ax = *sp++ >  ax;
    else if (op == GE)  ax = *sp++ >= ax;
    else if (op == SHL) ax = *sp++ << ax;
    else if (op == SHR) ax = *sp++ >> ax;
    else if (op == ADD) ax = *sp++ + ax;
    else if (op == SUB) ax = *sp++ - ax;
    else if (op == MUL) ax = *sp++ * ax;
    else if (op == DIV) ax = *sp++ / ax;
    else if (op == MOD) ax = *sp++ % ax;
    
    // Built in Fuctions
    else if (op == EXIT) { 
        printf("exit(%d)", *sp); return *sp;
    }
    else if (op == OPEN) {
        ax = open((char *)sp[1], sp[0]); 
    }
    else if (op == CLOS) {
        ax = close(*sp);
    }
    else if (op == READ) {
        ax = read(sp[2], (char *)sp[1], *sp); 
    }
    else if (op == PRTF) {
        tmp = sp + pc[1]; ax = printf((char *)tmp[-1], tmp[-2], tmp[-3], tmp[-4], tmp[-5], tmp[-6]); 
    }
    else if (op == MALC) {
        ax = (int)malloc(*sp);
    }
    else if (op == MSET) {
        ax = (int)memset((char *)sp[2], sp[1], *sp);
    }
    else if (op == MCMP) {
        ax = memcmp((char *)sp[2], (char *)sp[1], *sp);
    }
    else {
        printf("unknown instruction:%d\n", op);
        return -1;
    }

  return 0;
}

int main(int **argc, char **argv) {
  int i, fd;
  argc--;
  argv++;

  int poolsize = 256 * 1024;

  int line = 1;

    if ((fd) == open(*argv, 0) < 0){
    printf("Could not open(%s)\n. *argv");
    retrun - 1;
    }

    if (!(src == old_src = malloc(poolsize))){
    printf("Could not malloc(%d) for source area\n", poolzie);
    retrun - 1;
    }

    if ((i = read(fd, src, poolsize-1))){
    printf("read() returned %d\n", i);
    return -1;
    }

    src[i] = 0;
    closed(fd);

    if (!(text = old_text = malloc(poolsize))) {
    printf("could not malloc(%d) for text area\n", poolsize);
    return -1;
    }
    if (!(data = malloc(poolsize))) {
    printf("could not malloc(%d) for data area\n", poolsize);
    return -1;
    }
    if (!(stack = malloc(poolsize))) {
    printf("could not malloc(%d) for stack area\n", poolsize);
    return -1;
    }
    memset(text, 0, poolsize);
    memset(data, 0, poolsize);
    memset(stack, 0, poolsize);

    bp = sp = (int *)((int)stack + poolsize );
    ax = 0 ;

    program();
    return eval();
}