Re: crash upon startup in GWorkcenter, Recycler, ProjectCenter and Gorm

[Richard Frith-Macdonald]

> On 23 Dec 2017, at 09:42, Richard Frith-Macdonald 
> <richard.frith-macdonald@theengagehub.com> wrote:
> 
> 
> 
>> On 23 Dec 2017, at 09:32, Richard Frith-Macdonald 
>> <richard.frith-macdonald@theengagehub.com> wrote:
>> 
>> 
>> So the difference between the offsets in the runtime (correct) and the 
>> compiler (wrong) was 16 bytes, with the runtime thinking the strruct size 
>> was 32 and trhe compiler thinking it was 16;
>> 
>> It seems the compiler is sizing the structure as if it contained a pointer 
>> and two integers when it should actually be two pointers and three integers;
> 
> No, my mistake, that's rubbish ... on a 64bit processor the fieldds only 
> occupy 28 bytes, so the 32 byte offset is produced by alignment rules 
> rounding up to a 16byte boundery.
> In that case, the offsets calculated by the compiler would be consistent with 
> it ignoring the two __unsafe_unretained pointers.  Perhaps that is a clue?

It occurs to me that this is not anything like that simple :-(

While the compiler is getting the offset to _gcontext wrong, it's still getting 
the offset to the next ivar (_runLoopInfo) correct, so it can't just be that 
it's calcularing the size of the struct incorrectly.