[lkml]   [2007]   [Jun]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 16/16] fix handling of integer constant expressions
>> Here are three independently invalid non-ICEs that sparse doesn't
>> diagnose.
>> extern int f(void);
>> enum { cast_to_ptr = (int) (void *) 0 };
>> enum { cast_to_float = (int) (double) 1 };
> Those two *really* shouldn't fail. I don't care if the C standard says
> so,
> that is *fine*.

GCC doesn't guarantee you this, either.

> In particular, "offsetof()" should be portably able to basically be the
> standard #define, which involves an integer cast from a constant
> pointer.
> That had *better* be a valid constant integer expression, because it's
> very useful.

Yes it's useful. That's why GCC gives you __builtin_offsetof()
for this purpose.

> And I think standards can go screw themselves, and you can make it an
> error with some "--standard-pedantic" switch or similar.
> Standards are just random pieces of paper, for crying out loud! They
> have
> zero relevance in the end.

Sure, as long as you don't care about compatibility across
compilers, what matters is what the compilers you _do_ use
actually implement. And note that GCC doesn't guarantee
you much over what the C standard does. Almost everything
it allows extra is just an implementation side effect.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2007-06-28 11:11    [W:0.083 / U:4.124 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site