macro_x madness heads up

[Andreas Ericsson]

On 11/05/2010 12:12 PM, Ton Voon wrote:
> 
> On 5 Nov 2010, at 09:45, Andreas Ericsson wrote:
> 
>> Using this completely untested program, what output do you get?
>>
>> #include<sys/types.h>
>> #include<stdio.h>
>> #include<unistd.h>
>> #define psize(type) printf("sizeof(" #type ") = %d\n", sizeof(type))
>>
>> int main(int argc, char **argv)
>> {
>> 	psize(time_t);
>> 	psize(__darwin_suseconds_t);
>> 	psize(int);
>> 	psize(long);
>> 	psize(off_t);
>> 	psize(void *);
>> 	psize(long long);
>> 	return 0;
>> }
> 
> I get:
> 
> $ ./a.out
> sizeof(time_t) = 4
> sizeof(__darwin_suseconds_t) = 4
> sizeof(int) = 4
> sizeof(long) = 4
> sizeof(off_t) = 8
> sizeof(void *) = 4
> sizeof(long long) = 8
> 
> macbook 10.5, 32bit.
> 

Basically, size_t == int == long gcc should just shut the fsck up
about those.

time_t == __darwin_suseconds_t. There's no portable way to print
time_t except casting the argument to unsigned long, so I'll do
that.

The only thing that differs between your system and mine is off_t
not being same size as (void *), which is extremely odd indeed.
It really should be the same as a 'long' on all systems (long long
is C99-ish, so we can't really use that).

size_t gets its printf() format spec from C99 as well. The portable
way of printing it without warnings is to cast it to unsigned long
and use %lu in the format string.

Yuck and yuck for such types tbh.

-- 
Andreas Ericsson                   andreas.ericsson at op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231

Considering the successes of the wars on alcohol, poverty, drugs and
terror, I think we should give some serious thought to declaring war
on peace.

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