[fpc-devel]PowerPC, TypInfo

[Mattias Gaertner]

On Sun, 15 Aug 2004 03:18:59 +0200  Mattias Gaertner
<nc-gaertnma at netcologne.de> wrote:

> On Sat, 14 Aug 2004 23:59:55 +0200  Jonas Maebe <jonas at zeus.ugent.be>
> wrote:
> 
> > 
> > On 14 aug 2004, at 21:07, Mattias Gaertner wrote:
> > 
> > >> The GetOrdProp is used to read boolean values. It reads a longint and
> > >> applies "and $ff" to get only the lowest byte. Under PowerPC the 
> > >> boolean
> > >> value is stored just like under i386 in the first byte. Reading the
> > >> longint under i386 works, but of course it does not under powerpc.
> > >[...]
> > > I just found out, that this is also the case for ShortInt, SmallInt, 
> > > Word
> > > and Byte, but not for enums.
> > 
> > To me, the fact that it always reads a longint regardless of the size 
> > of the property seems to be inherently wrong. What if the last field of 
> > a class is a byte? Then you can read past the end of the class, 
> > possibly into unallocated memory causing a crash, no?
> 
> Good point.
> Looking at SetOrdProp, I see, that it works correct with PByte, PWord,
> PLongInt. 
> So GetOrdProp is buggy.
> 
> I will send a patch, when I completed the other tests. 

Attached patch was tested under i386 and ppc.


Mattias

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