LLVM build on MinGW

building llvm-2.6

1. download and install MinGW
2. download and install cmake
3. download llvm
4. tar xvzf llvm-2.6.tar.gz
5. mkdir llvm-cmake
6. cd llvm-cmake
7. cmake -G "MinGW Makefiles" ..\llvm-2.6
8. it'll fail
9. open CMakeCache.txt
10. write CMAKE_C_COMPILER_ENVVAR:FILEPATH=C:/MinGW/bin/gcc.exe
11. cmake -G "MinGW Makefiles" ..\llvm-2.6
12. mingw32-make

For llvm 2.7,

1. unzip llvm-2.7
2. unzip clang source under llvm-27/tools/clang
3. cd llvm-cmake
4. cmake -G "MinGW Makefiles" -DCMAKE_INSTALL_PREFIX="/home/opt/llvm" ..\llvm-2.7
5. mingw32-make DESTDIR=C: install