PATCH: ppc fix 2

Greg Turner gmturner007 at
Wed Oct 30 10:13:36 CST 2002

On Wednesday 30 October 2002 07:22 am, Marcus Meissner wrote:
> 	Fixed LITTLE_ENDIAN_32_READ macro to at least compile.

btw, this seems to imply that even with the parentheses fix, it's still 
not right... is that the case?  You seem like somebody who's up on PPC 
issues.  Note that this is only intended to support UINT32's (I'll make 
that clearer by changing the macro names in an upcoming patch).

There is another issue with the DataRepresentation stuff that I didn't 
think of until this morning.  NDR allows several different modes in 
terms of endianness, float representation, signed int representation, 
etc.  MS takes advantage of this by having different "native" data 
representations, based on the platform.  Looking at the Platform SDK 
rpcndr.h, for example, PPC gets big-endian, i386 gets little-endian.

Then, it seems, they implement their marshall/unmarshall code in terms 
of these "native" representations.  I'm deducing this from the 
MIDL-generated stub code; that code compares the DataRepresentation 
coming off the wire to the native DataRepresentation; if there's a 
mismatch, it converts before calling the unmarshall code (currently the 
conversion functions are unimplemented in wine).

What this all means, I think, is that my implementation is wrong for 
non-i386 platforms.  I was hard-coding the native data representation 
to little-endian (the i386 way).  This will work for i386, but for 
other platforms, it will break against precompiled binaries, because 
the assumed native data representation is compiled right in to the 
executable via #define's.  To fix, I think I need to have per-platform 
native DataRepresentations like microsoft, and change the 
marshall/unmarshall code to use it.

Anyhow, just thinking aloud there, and, I guess, hoping that if I'm 
getting this all wrong, someone will correct me.   My original question 
is the main one: are the semantics of my macro's wrong, or just the 
parentheses thing?


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