Re: [ros-dev] gcc problem or not

[Thomas Weidenmueller]

Hartmut Birr wrote:
> Hi,
>
> I was always the opinion  that the examination of a test condition stops
> if the result can not change again. A test condition like this:
>
> if (pointer == NULL || pointer->member == 0)
>
> should never access pointer->member if pointer is zero. Compared with
> the code above, it is possible that gcc build the result from the right
> side of the OR statement. This may hit a page fault. Is this a bug in gcc?

It should definitely not dereference if it's NULL. The conditions should 
be checked from left to right in this case, no matter how much was 
optimized.

Thomas