"LLVM GCC 4.2" is used by default in initial release 4. (i.e.: LLVM server with GCC 4.2 analyzer).
You can verify this by creating a new project, selecting the main goal of the project (bit at the top of the left panel), and then select the "Build Settings" option in the main area. If you then select βAllβ (default is βBasicβ) and scroll down, you will see βLLVM GCC 4.2β, selected by default.
, , GCC 4.2 ( Xcode 3.x) LLVM.
( Xcode 3.2.x) Xcode 3.2.1 GCC CLANG LLVM demystification .