[Qt-interest] Qt SDK 4.6 on OS X 10.6: Compile 64bit possible?

[Oliver.Knoll at comit.ch]

Richard wrote on Tuesday, December 08, 2009 4:03 PM:

> > 	seemed to support my assumption: "Qt follows suit and is also 64-bit
> > by default when building for Cocoa (Select this with the -cocoa flag
> > at the configure line or use the -arch x86_64 flag)."  
>
> If you build your app against Qt/Cocoa on Snow Leopard, it should be
> 64 bit (only) by default (on Leopard it will be 32 bit).

Thanks, that is what I understood ("gcc on OS X 10.6 defaults to 64bit, whereas on < 10.6 it defaults to 32bit"). What I actually meant was that above statement from the Qt Labs somehow made me believe that when I downloaded the latest Qt SDK it would also somehow to "default" to 64bit (respective at least to Cocoa instead of Carbon and I would have the choice between 32 and 64 bit builds).

As someone else has also requested in the meantime the documentation on the Qt SDK binary download site should be more descriptive about "what is in the bottle".

Also on the binary "Qt library only" the automatic download really chooses the Carbon by default. I had to cancel that and click on the "Cocoa" build instead. I guess like this many other people - when Mac beginners like me ;) - run into the same Carbon vs Cocoa issue.

But hey!, we survived the "DLL Hell"(tm), the "Manifest Fiasko"(tm)... Welcome to "Carbonated Coconut Confusion"(tm) :))

> > 	One last question, out of curiosity: I am not yet familiar with
> > "Frameworks", but I understand that the "Cocoa" port supports both
> > 32bit and 64bit applications. 

> E.g. the
> /Library/frameworks/QtGui.framework/QtGui binary for the Qt/Cocoa
> package will contain both i386 and x86_64, and as such, be twize the
> size of a build that only supported a single architecture.    

Ok, thanks. So I understand e.g. the QtGui binary really is just one big huge binary, containing both 32bit and 64bit code. In other words, if I really "just want to ship 64bit", I need to compile Qt myself and make sure only the 64bit version is compiled - given the "32bit and 64bit Qt" I can't decide "only extract the 64bit Qt libraries and put alongside my app".

It is all pretty new for me this Mac development, your help very much appreciated!

Thanks, Oliver
-- 
Oliver Knoll
Dipl. Informatik-Ing. ETH
COMIT AG - ++41 79 520 95 22