update GCC on mac os x 10.7.4

Dear,

I need a newer version of gcc to compile libgimli (http://sourceforge.net/projects/libgimli/) under mac os x 10.7.4. I already tried macports, homebrew and compiling from hand, but I keep getting errors. Below is the error if I use Homebrew. How should I proceed?

hecking for x86_64-apple-darwin11.4.0-gcc... /private/tmp/homebrew-gcc-4.7.0-OLFi/gcc-4.7.0/build/./gcc/xgcc -B/private/tmp/homebrew-gcc-4.7.0-OLFi/gcc-4.7.0/build/./gcc/ -B/usr/local/Cellar/gcc/4.7.0/gcc/x86_64-apple-darwin11.4.0/bin/ -B/usr/local/Cellar/gcc/4.7.0/gcc/x86_64-apple-darwin11.4.0/lib/ -isystem /usr/local/Cellar/gcc/4.7.0/gcc/x86_64-apple-darwin11.4.0/include -isystem /usr/local/Cellar/gcc/4.7.0/gcc/x86_64-apple-darwin11.4.0/sys-include

checking for suffix of object files... configure: error: in `/private/tmp/homebrew-gcc-4.7.0-OLFi/gcc-4.7.0/build/x86_64-apple-darwin11.4.0 /libgcc':

configure: error: cannot compute suffix of object files: cannot compile

See `config.log' for more details.

make[2]: *** [configure-stage1-target-libgcc] Error 1

make[1]: *** [stage1-bubble] Error 2

make: *** [bootstrap] Error 2

==> Build Environment

CPU: quad-core 64-bit sandybridge

MacOS: 10.7.4-x86_64

Xcode: 4.3.2

"--use-clang" was specified

CC: /usr/bin/clang

CXX: /usr/bin/clang++ => /usr/bin/clang

CFLAGS: -Os -w -pipe -march=native -Qunused-arguments -m64

CXXFLAGS: -Os -w -pipe -march=native -Qunused-arguments -m64 -U_GLIBCXX_DEBUG -U_GLIBCXX_DEBUG_PEDANTIC

LDFLAGS: -arch x86_64

MAKEFLAGS: -j4

Error: Failed executing: make bootstrap (.rb:)

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https://github.com/mxcl/homebrew/wiki/reporting-bugs