How to save IR to a file and build it to an executable file?

Now I use clang build my .c file to .s file. And I have used the llvm API modify the IR. However, now I can't save my modified IR to a file. I want to use "LLVMWriteBitcodeToFile", but I can't find the struct of "LLVMOpaqueModule"; I want to use "WriteBitcodeToFile", it always show me "type mismatch". And I also want to know how to build an IR file to a executable file.

Next are two methods I use to save a module:

1、First use WriteBitcodeToFile

bool unbuffered = false; 
llvm::raw_ostream ro(unbuffered); 
WriteBitcodeToFile(m, ro); 

2、Second use LLVMWriteBitcodeToFile

const char *Path = "hello2.s"; 
int ans = LLVMWriteBitcodeToFile(m, Path); 

note: m is a point of Module instance