Re: [stunnel-users] [PATCH] Fix undefined aliasing in libwrap.c

----- "Michal Trojnara" <[email protected]> wrote:

Miloslav Trmac wrote:

...

The attached patch changes the code not to access a part of a char[...] array using an int *, which is undefined in ISO C.

Casting pointers is undefined? No (as long as alignment restrictions are not violated), but accessing an object of one type via a pointer of other type is undefined for most combinations of the types.

Where did you find it? In the C standard :) Besides, GCC warns quite loudly.

http://mail-index.netbsd.org/tech-kern/2003/08/11/0001.html is a good description of the issue. Mirek