Compiling bug when use vortex branch

[wangzhenyu32]

Command:
cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=RelWithDebInfo -DLLVM_ENABLE_PROJECTS="clang" -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi;libunwind" -DLLVM_ABI_BREAKING_CHECKS=FORCE_OFF -DLLVM_INCLUDE_EXAMPLES=OFF -DLLVM_INCLUDE_TESTS=OFF -DBUILD_SHARED_LIBS=True -DCMAKE_INSTALL_PREFIX=$LLVM_VORTEX -DLLVM_BUILD_TESTS=False -DDEFAULT_SYSROOT=$RISCV_TOOLCHAIN_PATH/riscv32-unknown-elf -DLLVM_DEFAULT_TARGET_TRIPLE="riscv32-unknown-elf" -DLLVM_TARGETS_TO_BUILD="RISCV" ../llvm

Error:
CMake Error at /root/llvm/libunwind/src/CMakeLists.txt:86 (message):
Compiler doesn't support generation of unwind tables if exception support
is disabled. Building libunwind DSO with runtime dependency on C++ ABI
library is not supported.

-- Configuring incomplete, errors occurred!
See also "/root/llvm/build/runtimes/runtimes-bins/CMakeFiles/CMakeOutput.log".
See also "/root/llvm/build/runtimes/runtimes-bins/CMakeFiles/CMakeError.log".
make[2]: *** [runtimes/CMakeFiles/runtimes.dir/build.make:107: runtimes/runtimes-stamps/runtimes-configure] Error 1
make[1]: *** [CMakeFiles/Makefile2:27681: runtimes/CMakeFiles/runtimes.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs....
[ 98%] Building CXX object tools/opt/CMakeFiles/opt.dir/PassPrinters.cpp.o
[ 98%] Building CXX object tools/llvm-reduce/CMakeFiles/llvm-reduce.dir/deltas/ReduceGlobalVars.cpp.o
[ 98%] Building CXX object tools/opt/CMakeFiles/opt.dir/PrintSCC.cpp.o
[ 98%] Building CXX object tools/opt/CMakeFiles/opt.dir/opt.cpp.o
[ 98%] Building CXX object tools/llvm-reduce/CMakeFiles/llvm-reduce.dir/deltas/ReduceMetadata.cpp.o
[ 98%] Linking CXX executable ../../../../bin/c-index-test
[ 98%] Building CXX object tools/llvm-reduce/CMakeFiles/llvm-reduce.dir/deltas/ReduceArguments.cpp.o
[ 98%] Built target c-index-test
[100%] Building CXX object tools/llvm-reduce/CMakeFiles/llvm-reduce.dir/deltas/ReduceBasicBlocks.cpp.o
[100%] Building CXX object tools/llvm-reduce/CMakeFiles/llvm-reduce.dir/deltas/ReduceInstructions.cpp.o
[100%] Linking CXX executable ../../bin/llvm-reduce
[100%] Built target llvm-reduce
[100%] Linking CXX executable ../../bin/opt
[100%] Built target opt
make: *** [Makefile:152: all] Error 2