我在跑狮子。我有gcc的这两个版本，两者都声称是相同的，但diff声称二进制文件不同。我试图在OS X上了解gcc的情况。它们之间有什么区别？
$ /usr/bin/gcc-4.2 --version
i686-apple-darwin11-llvm-gcc-4.2 (GCC) 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.9.00)
Copyright (C) 2007 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ /usr/bin/i686-apple-darwin11-llvm-gcc-4.2 --version
i686-apple-darwin11-llvm-gcc-4.2 (GCC) 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.9.00)
Copyright (C) 2007 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ diff /usr/bin/gcc-4.2 /usr/bin/i686-apple-darwin11-llvm-gcc-4.2
Binary files /usr/bin/gcc-4.2 and /usr/bin/i686-apple-darwin11-llvm-gcc-4.2 differ