[Cryptography] Apple and OpenSSL

[Dennis E. Hamilton]

Brief correction below.

    -----Original Message-----
    From: Dennis E. Hamilton [mailto:dennis.hamilton at acm.org] 
    Sent: Monday, April 21, 2014 14:06
    To: 'Cryptography Mailing List'
    Cc: 'Theodore Ts'o'
    Subject: RE: [Cryptography] Apple and OpenSSL

    [ ... ]

    On calling any of those methods via the ABI, the location of 
    the PPV pointer is always the first parameter.  

    [ ... ]

On calling any of those methods via the ABI, the VALUE of the PPV is always the first parameter, not the location.  So it is a pointer to the PV and the methods are implemented to locate what they need based on that location.

Aside: In C++, interfaces tend to be defined in header files such that this aspect of providing what might happen to be a "this" pointer to an interface method is invisible and taken care of as part of the C++ machinery for access to implementations of abstract objects.  There are ways to do this that are indifferent to where the particular compiler puts transfer vectors when left to its own devices.

 - Dennis