Mail Archives: cygwin/2004/06/15/13:54:08
Hi,
> And the answer there will probably be that if your code depends on
whether
> this function is a macro or a real function then your code is not valid C.
> The C language spec specifically says that implementations are free to
> provide library functions as macros as well as functions. See
>
> http://www.opengroup.org/onlinepubs/009695399/basedefs/math.h.html
>
> and in particular the lines that say "The following shall be declared as
> functions and may also be defined as macros. Function prototypes shall be
> provided."
>
> So if your code has a problem with that, your code does not comply with
> the C language spec.
>
> cheers,
> DaveK
Dave,
To be fair, the original poster described the exact problem:
> log2 as macro is hard to use in projects that also define a log2 function.
I'm not sure how your link can be reconciled with this, but at a guess,
projects that define a log2() function are expected to follow "#include
<math.h>" with "#undef log2".
Yes, you are correct, we do this now in this way. Cygwin is the only
environment for which we have to do this and I just don't like it. It means
we have to include math.h in a header file where we don't need it. A change
to a function would make life easier.
Johnny
--
Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Problem reports: http://cygwin.com/problems.html
Documentation: http://cygwin.com/docs.html
FAQ: http://cygwin.com/faq/
- Raw text -