On 23/07/2012 20:05, Ángel González wrote:
On 23/07/12 12:35, Jan Smets wrote:
Can anyone help me hacking this in or at least give me some hints how
to do this.
(e.g, how do I know if value is used twice in the if()?) I had a
look at c-family/c-common.c but I don't see how this can be done.
Any help is appreciated.
Thanks
- Jan
I would
a) Replace all such usages with a macro like: CHECK_RANGE(value,
tSomeType_MIN, tSomeType_MAX) (or you could have a macro per type and
the min & max hardcoded on each one). This makes easy to change the
implementation later or even disable it depending on the compilation.
b) Instead of doing the check, convert it to a call to an inline
function. If ((foo < min) || (foo > max)) will give the warning, but
if (check_range(foo, min, max)) won't, even if it's defined as:
static inline int check_range(int value, int min, int max) {
return (value < min) || (value > max);
}
and thus completely optimized inline [you can also mark it as
__attribute__((always_inline)) if you want to force it, it still won't
warn... yet].
||
I did consider these options. But they're not user friendly IMHO. I can
surely tell 300 devs about this macro/inlined function. But how many
will remember this after a month? A year ?
The result is that people start avoiding MIN checks in their code and
functionality gets broken.
So I still prefer a way to disable this checking when there is a
larger-than and less-than compare of the same variables in the same if()
block.
Where do I start? I don't expect people to do this for me, but I could
use some pointers to get started.
Thanks
- Jan
