[Interest] Building 32-bit Qt 5 on Mac

[Michael Jackson]

On Apr 23, 2012, at 4:32 PM, Nikos Chantziaras wrote:

> On 23/04/12 23:19, Paul Miller wrote:
>> On 4/23/2012 1:19 PM, Stephen Chu wrote:
>>> Will 32-bit build be supported in Qt 5? Or we Mac guys will all have to
>>> force our users to 64-bit land?
>> 
>> I don't know how far back you need to support, but we dropped support
>> for 32 bit Mac last year. Pretty much every Mac built in the last 5
>> years has bee on a 64 bit architecture, and Leopard up has been fully 64
>> bit. We make imaging products and nobody has ever complained about lack
>> of 32 bit. Pretty much everyone in the industry is running Snow Leopard
>> or Lion these days.
> 
> Are there 32bit-only 10.5 systems?  Can it even be installed on a Mac 
> that lacks a 64bit CPU?
> 
> It's a bit difficult to find accurate information.  I ask because Qt 
> supports down to OS X 10.5.  10.4 is not supported (at least not with 
> Cocoa, and Carbon was deprecated by Qt I think).  If 10.5 can't be 
> installed on 32bit Macs, then it makes sense to build for 64bit.
> 
> The same goes for the PowerPC 10.5 Macs though.  Can 10.5 be installed 
> on 32bit-only PPCs?


I am going to do this from memory but www.apple.com is going to be the source for the exact answer.

OS X 10.5 was both PPC and Intel and 32 and 64 bit (Kinda/ sort of).

You could install OS X 10.5 on 32/64 bit PPC and some Intel machines. Apple did early on use the Intel Core Duo and Core Solo which are 32 bit processors. So there are some intel machines that can run OS X 10.5 (even 10.4.11) but only in 32 bit mode.

OS X 10.6 & 10.7 Requirements:
http://support.apple.com/kb/HT4949

OS X 10.5 Requirements:
http://support.apple.com/kb/HT3759

The question you need to ask yourself is how many of your customers are still using OS X 10.5? If you have a relatively "new" app I would ditch 32 bit support and just go with 64 bit support from here on out. If you have some sort of custom app for an internal IT department or something special where you need to support back to OS X 10.5 I would just stick with Qt 4.7.4 which should have support for building all the way back to 10.5 with Cocoa or Carbon.

Hope that helps.
Mike Jackson