cmake -G"Unix Makefiles"要这样才可以,
D:\My Documents\qtproject\llvm\test_cmake>cmake -G"Unix Makefiles"
-- The C compiler identification is GNU 4.5.0
-- The CXX compiler identification is GNU 4.5.0
-- Check for working C compiler: E:/Programe/MinGW/bin/cc.exe
-- Check for working C compiler: E:/Programe/MinGW/bin/cc.exe -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler: E:/Programe/MinGW/bin/g++.exe
-- Check for working CXX compiler: E:/Programe/MinGW/bin/g++.exe -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Configuring done
-- Generating done
-- Build files have been written to: D:/My Documents/qtproject/llvm/test_cmake