On Fri, Aug 18, 2017 at 02:05:10PM +0200, Ulf Hermann wrote: > gcc defaults to using struct layouts that follow the native conventions, > even if __attribute__((packed)) is given. In order to get the layout we > expect, we need to tell gcc to always use the gcc struct layout, at > least for packed structs. To do this, we can use the gcc_struct > attribute. > > This is important, not only for porting to windows, but also potentially > for other platforms, as the bugs resulting from struct layout > differences are rather subtle and hard to find.
I don't have internet access at the moment to lookup the documentation for gcc_struct. And none of the sources I have locally at the moment seem to use gcc_struct. So I am not completely clear on why this is only needed for packed structs. Wouldn't this be a general problem for any struct that might be layed out differently but that we might map to some on-disk data structure? Cheers, Mark
