June
2nd,
2020
- CREATED
출처 : http://kernelnewbies.org/FAQ/DoWhile0
MACRO 사용시 do - while(0) 를 사용하는 이유에 대한 article.
번역할 필요없이 코드만 한번씩 들여다봐도 직관적으로 이해할 수 있다.
Why do a lot of #defines in the kernel use do { … } while(0)?
There are a couple of reasons:
- (from Dave Miller) Empty statements give a warning from the compiler so this is why you see #define FOO do { } while(0).
- (from Dave Miller) It gives you a basic block in which to declare local variables.
- (from Ben Collins) It allows you to use more complex macros in conditional code. Imagine a macro of several lines of code like:
#define FOO(x) \
printf("arg is %s\n", x); \
do_something_useful(x);
– SNIP – 위 링크 참조
