datatype misalignment

[simonjacobs]

[R0B]

[simonjacobs]

[R0B]

[R0B]

[simonjacobs]

[Digby]

[Dan East]

[Dan East]

Here is a specific example from the pWolf source. This appears to be exactly the same problem you're encountering, except the code is wrapped in a define. The original code is commented out. My CE alternative is the following 3 lines:<br>[fixed]<br>//Dan East: Alignment problems here:<br>//length = *( ( unsigned short * ) demoptr )++;<br>length = ( * ( ( unsigned char * ) demoptr ) ++ );<br>length |= ( * ( ( unsigned char * ) demoptr ) ++ )<<8;<br>demoptr++;<br>[/fixed]<br><br>Dan East

[Dan East]

Another alignment fix from pWolf, again, almost the exact same thing as the problem you're encountering. This differs from the above example in that it is a 32 bit int instead of a word. "source" is an unsigned char.<br>[fixed]<br>#ifndef _WIN32_WCE<br>expanded = *( long * )source;<br>source += 4; // skip over length<br>#else<br>//Dan East: Workaround for alignment issues<br>expanded = *source++;<br>expanded |= ( *source++ ) << 8;<br>expanded |= ( *source++ ) << 16;<br>expanded |= ( *source++ ) << 24;<br>#endif<br>[/fixed]<br><br>Dan East

[R0B]

Thanks Dan, I will try that now.  Digby, I respect your programing skill and knowledge, but I think that you should relax.  I have tried everything with that "__unaligned" definition, and it won't help in this situation.  I just happedened to post an example where I tried casting __unaligned to see if that would help.  But, it failed to change the code at all.  By the way, you should have used muffins.  And, they don't go on the hood of the car, they go in the trunck.

[R0B]

Ok, I get what you are saying Dan.  Your example is just the reverse of mine.  I have to store the value or the ULONG in *p a byte *.  So, here is my thought.<br><br>*p ++ = (byte)wadfiles[i]->filesize; <br>*p ++ = (byte)wadfiles[i]->filesize <<8;<br>p++;<br><br>Only that won't work because *p ++ = (byte)wadfiles[i]->filesize; would try to store everything in *p, not just the lower byte.  But wait, wouldn't I have to do that four times, since p is a byte, but filesize is a ULONG.  Also, p points to the address of a unsigned char[500].  Would that mess it up at all.  I think that we are getting somewhere, but I could still use more help.<br><br>

[simonjacobs]

Rob: Does this work:<br><br>unsigned char *p = something;<br>ULONG temp = wadfiles->filesize;<br><br>memcpy(p, &temp, 4);<br><br>

[simonjacobs]

sorry, i'm tired, what i meant was:<br><br>memcpy(p,&wadfiles->filesize,4);<br><br>

[simonjacobs]

my theory is that memcpy will take care of the alignment problem <br><br>i am probably wrong as usual.<br><br>it WOULD be funny if all this hassle could have been avoided with a single memcpy command though!