> Date: Wed, 07 Dec 2005 09:18:53 +0100 > From: "Jan Beulich" <[EMAIL PROTECTED]>
Just for the record (in case someone else has the same thoughts) and because I'd already written most of the reply, I also replied to your first email. See last for your follow-up. > What has the alignment of type 'long long' to do with structure > packing? Only the obvious(?): if long long is usually padded in a structure, then marking it with attribute-packed has effect. IIUC for netware, you pack everything in structures *except* long long, which you pad to 32-bit alignment. Right? If not, then the warning emission machinery is wrong. > Structure packing is exactly to override the alignment of the > type. And in the given situation, alignment of 'long long' is at least > 32 (bits), whereas BITS_PER_UNIT is 8, and hence the attribute is really > not ignored (because the alignment gets overridden in order to pack the > field), hence the expectation of a warning here seems wrong. If not, can > you explain what it is that makes you expect a warning here? If "long long" is packed by default then a target default_packed *should* get the "is ignored" warning. On the other hand, if the warning is considered correct as emitted, you need to write something like a default_packed_except_long_long testsuite thingy and use that here. See default_packed bits. And later: >It should not only check TYPE_ALIGN (), but also consider current >structure packing in effect (and consequently, it should also be emitted >e.g. when #pragma pack(1) is in effect on a target that doesn't default >to packed structures). Agreed. I'd be happy to see this. brgds, H-P
