function inorder($root)
gcc version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00)
configure:3438: $? = 0
configure:3427: gcc -V >&5
llvm-gcc-4.2: argument to `-V' is missing
configure:3438: $? = 1
configure:3427: gcc -qversion >&5
i686-apple-darwin11-llvm-gcc-4.2: no input files
configure:3438: $? = 1