fun.c

来自「test return point or point as param」· C语言 代码 · 共 70 行

#include <stdio.h>
#include "../inc/Test.h"
#include "../inc/data.h"


S_MmfCtrl * SetData(void)
{
	int sum;
	S_MmfCtrl *pS_MmfCtrl;

	pS_MmfCtrl = &SCtrl;

	sum = checksum(&SCtrl, 100);

	printf("sum is %x\n", sum);

	return pS_MmfCtrl;

}

static checksum(unsigned short *addr, int len)
{
	register int left = len;
	register unsigned short *w = addr;
	register int sum = 0;
	unsigned short answer = 0;

	while(left > 1)
	{
		sum += *w++;
		left -= 2;

		if(left == 1)
		{
			*(unsigned char *)(&answer) = *(unsigned char *)w;
			sum+= answer;
		} 
	}

	sum = (sum >> 16) + (sum & 0xffff);
	sum +=(sum >> 16);
	answer =~sum;
	
	return (answer);

}

int tttt = 9;

int* test(int *p)
{
   
   *p = 1000;
   return &tttt;
}


void test2()
{
	 int *p = NULL;
	 int val = 0;

	 p = &val;

     printf("val = %d, val = %d\n", val,val);
	 p = test(p);
	// *p = 99;
	 
     printf("val = %d, val = %d\n", val,val);
}