On Wednesday, July 6, 2011 12:14 CEST, David Chisnall <[email protected]> wrote: > On 6 Jul 2011, at 11:02, David Chisnall wrote: > > > On 6 Jul 2011, at 10:55, Sebastian Reitenbach wrote: > > > >> Error: Instance variables in NSTextTable overlap superclass NSTextBlock. > >> Offset of first instance variable, _layoutAlgorithm, is 196. Last > >> instance variable in superclass, _widthType, ends at offset 148. This > >> probably means that you are subclassing aclass from a library, which has > >> changed in a binary-incompatibleway. > > > > I think this is a bug in how libobjc2 is calculating sizes. The last ivar > > of NSTextBlock is an array of arrays, and my guess is that the runtime > > thinks that it is smaller than it is. > > Having said that, I can't actually reproduce this, and objc_sizeof_type() > seems to return the same size as sizeof() for me when I copy the last ivar > into a file and test it. > > Both of these numbers look a bit wrong. For me, class_getInstanceSize() > returns 172 for NSTextBlock, so unless you've got some very strict alignment > requirements 196 looks too large. The header doesn't seem to have been > modified for a long time, so I'm not sure how it could happen. IIRC, the alignment is fairly strict on sparc64, but I'm not an expert ;)
> > Can you tell me from the debugger: > > - What the type encoding of the last ivar is > - What the calculated size of the last ivar is Do you can give me a hint how I can figure this out? At which frame stack I should potentially go, or where to set a breakpoint, and what to enter? > - How big void* is on your platform (gdb) print sizeof(void*) $1 = 8 Sebastian > > David > > -- Sent from my brain > _______________________________________________ Discuss-gnustep mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnustep
