Does Objective-C compile to native code or byte-code?

Question

On OS X, does Objective-C compile to native code or byte-code?

Can Objective-C programs be compiled on Linux?

Answer 1

Objective-C is compiled to native code by either GCC or LLVM[*]. You can compile ObjC programs on Linux (the generic GCC will happily support ObjC, though it uses a different runtime library than either of the Apple ones). For a cross-platform API similar to Cocoa (i.e. derived from Cocoa) which will happily work on Linux and let you port some code between OS X and Linux, check out GNUstep: http://www.gnustep.org

[*]In fact, LLVM internally compiles the Objective-C to an internal bitcode representation, then to code for the target machine, so perhaps the answer is "both"…

Answer 2

Objective-C is a variant of C. It compiles to native code.

Answer 3

Yes, Objective-C compiles to machine code.

Objective-C compilers exist for Linux, but Cocoa is an OS X-only technology. I've heard of an open replacement called GNUstep, but don't know much about it.

Answer 4

It's native.

There is GNUstep which an Open Source implementation of the NeXT OpenStep specification written in Objective-C. Their implementation of the Cocoa API is not a direct match so a direct compilation without porting is not possible.