How to compile universal libraries on Mac OS X?

Question

This may be a very silly question, but I'm new to developing on Macs and am having a hard time with the universal binaries.

I've got an application that I'm compiling in QT Creator, which according to lipo is producing i386 architecture outputs. As I understand it, that means it is producing Mac OS X 32 bit outputs.

The application depends on two external libraries. One of these libraries I'm compiling by calling ./config first, and then make. ./config states that it is "Configured for darwin-i386-cc". However, after running make, and calling lipo on the result, the architecture is reported as x86_64.

Similarly, I have another external library. That one has no configure script, and I compile it simply by calling make. The output from this one too is x86_64.

How can I compile these two external libraries so that they produce something compatible with my application's i386 output? Better yet, how can I compile these two external libraries to produce universal libraries so I can produce a universal binary from my application that works on both 32 and 64 bit?

Also, based on the current state of the Mac world, are there any other platforms that I should be expected to target to create a proper, user-friendly Mac OS X universal binary?

Answer 1

Finally got it working.

In order to control the architecture of the target, I manually went in and edited the Makefiles.

For one of them, I added to the end of the line that starts with CFLAGS: -arch i386 -arch x86_64 -arch ppc This produced a universal binary.

For the other, when I did the same thing, the compile would error out. I had to cycle through and only put one arch at a time, and then after I produced all three, I called lipo on them with the -create flag to create a universal binary.