Using iOS 7 SDK with llvm-gcc-4.2

Question

I've installed xcode 5 and noticed that gcc compiler is deprecated. Assuming that I don't want to switch to Apple LLVM 5.0, here come my questions:

Is it possible to use iOS7 SDK and still compile in llvm-gcc-4.2?

If yes, how to do this?

If you don't know if that's possible, please don't post answers like "use clang, man", because they are not actually answering the questions I've posted.

Answer 1

Apple has removed the support for llvm-gcc-4.2 in XCode 5. Even if you install and change your base sdk to 6.1 sdk, you won't be able to build using llvm-gcc-4.2. So your only option is to continue using XCode 4.x if you want to use llvm-gcc-4.2.

Answer 2

LLVM-GCC is not included in Xcode 5.

I got above line from https://developer.apple.com/library/ios/documentation/DeveloperTools/Conceptual/WhatsNewXcode/Articles/xcode_5_0.html

So the question is what to use instead of llvm-gcc ?

Answer 3

Is it possible to use iOS7 SDK and still compile in llvm-gcc-4.2?

If you want to compile your whole app using llvm-gcc-4.2: Probably not. I haven't checked this myself, but the iOS 7 headers would only need to add a single dependency on a clang feature missing in llvm-gcc-4.2 and you're swimming in compile errors. You may be able to hack your way through them, but it would likely be easier (not to mention more future-proof) to suck it up and upgrade to clang.

If you only need to compile some of your app using llvm-gcc-4.2: Sure, as long as you don't need to import any iOS 7 headers in the parts that you build with llvm-gcc-4.2.

You could try moving the problematic bits off to a static library, compiling that with gcc, then linking in to the final app, built with clang. You won't be able to target 64-bit, as llvm-gcc-4.2 doesn't can't generate armv8 code, but it should work otherwise.

One caveat: If your static lib uses C++, there may be some problems due to ABI and std library differences. But those are solvable problems, at least.

Answer 4

You could use homebrew to install the gcc version you need. Most probably all your Makefiles will need to be corrected (sigh)

I did:

brew search gcc

And the results:

homebrew/versions/gcc43     
homebrew/versions/gcc45 
homebrew/versions/gcc47    
homebrew/versions/gcc49
homebrew/versions/gcc44
homebrew/versions/gcc45
homebrew/versions/gcc48    
homebrew/versions/llvm-gcc28
homebrew/dupes/apple-gcc42