xcodebuild necessary on Mac?

[Wang Weijun]

I just installed a brand new Mavericks and go straight to 'bash configure' for jdk9/dev. A dialog pops out asking me to choose between installing Xcode and downloading command line tools. I choose the latter and after they are installed I run configure again, and it shows

  Failed to determine Xcode version.

Looking into common/autoconf/toolchain.m4 and it's running xcodebuild to find out the version. Since this is Mavericks I think it should be 5. So I write my own xcodebuild that shows itself as Xcode 5 and configure passed.

And the build runs fine (after installing XQuartz). So why is xcodebuild necessary? What must I install Xcode to build openjdk? I can see 'gcc --version' showing 'LLVM' and '5.1' words also.

Thanks
Max