Re: Any interest in buildfarm a member using Apple's llvm-gcc-4.2 or clang?

On Sep 8, 2009, at 4:18 PM, Tom Lane wrote:

> Robert Creager <robert@logicalchaos.org> writes:
>> I'll set up one or  two more 'machines' if there is interest (Snow
>> Leopard)
>
> LLVM, perhaps, though are you sure that llvm and gcc aren't the
> same thing under the hood on SL?  I thought I'd read somewhere that
> Apple had turned gcc into a wrapper around the llvm code generator.

Well, the versions reported are definitely different.

% gcc --version
i686-apple-darwin10-gcc-4.2.1 (GCC) 4.2.1 (Apple Inc. build 5646)

Robert@dhcp-ubrm05-218-133:/usr/local/src/build-farm-3.2_llvm
% /Developer/usr/llvm-gcc-4.2/bin/llvm-gcc-4.2 --version
i686-apple-darwin10-llvm-gcc-4.2 (GCC) 4.2.1 (Based on Apple Inc.  
build 5646) (LLVM build 2118)

And the llvm tools you only get with the Xcode install, and the sizes  
of the two gcc compilers are very different.

And, the llvm version takes the -flto, where the normal one doesn't:

/Developer/usr/llvm-gcc-4.2/bin/llvm-gcc-4.2 -flto main.c -o main_llvm
/usr/bin/gcc-4.2 -flto main.c -o main_gcc
cc1: error: unrecognized command line option "-flto"
make: *** [main_gcc] Error 1
       -flto           Enable LLVM Link Time Optimization.

And, the binaries are different for the same simple program.

So, I'm convinced they are different (where I wasn't sure before).

Later,
Rob