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如何从结构的某个域地址得到结构的起始地址？

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struct test 
{
  int a;
  int b;
  float c;
}

如何从struct test的b的地址反推struct test的地址？

 

4 个答复

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windows ddk提供了个经典的宏：

#define CONTAININT_RECORD(address, type, field) \
             ((type*)((PCHAR)(address) - (PCHAR)(&((type*)0)->field)))

linux内核也有个同样功能的宏：

#define container_of(ptr, type, member) ({                  \
    const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
    (type *)( (char *)__mptr - offsetof(type,member) );})
#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)

参考：

浅析container_of(ptr, type, member)

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vote up0vote down

You've got it in one. Couldn't have put it betetr.

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vote up0vote down

Got it! Thanks a lot again for hpelnig me out!

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vote up0vote down

Grade A stuff. I'm unqeustinoably in your debt.

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