how to pack data structures (i386)?

[Andi Kleen]

Will Menninger <william.l.menninger@boeing.com> writes:

> Hello,
> 
> I've found gcc to be an extremely reliable compiler.  Thanks for your
> efforts.  I have a question for you:
> 
> I'm using gcc (2.7.something) with an i386 system.  Is there a compiler
> option or a #pragma statement I can use to have it pack data structures
> as tightly as possible (e.g. not pad char's out to 4-bytes)?

See the gcc manual, "C extensions", "Variable attributes" 
Basically you add __attribute__((packed)) to a structure definition.
Newer gcc should also be able to understand #pragma pack for compatibility,
not sure if 2.7.* does though; it's a rather old compiler.



-Andi