LLVM Essentials

Emitting a return statement

A function might return a value or it may return void. Here in our example, we have defined that our function returns an integer. Let's assume that our function returns 0. The first step is to get a 0 value, which can be done using the Constant class.

Builder.CreateRet(Builder.getInt32(0));

The overall code is as follows:

#include "llvm/IR/IRBuilder.h" #include "llvm/IR/LLVMContext.h" #include "llvm/IR/Module.h" #include "llvm/IR/Verifier.h" #include <vector> using namespace llvm; static LLVMContext &Context = getGlobalContext(); static Module *ModuleOb = new Module("my compiler", Context); Function *createFunc(IRBuilder<> &Builder, std::string Name) { FunctionType *funcType = llvm::FunctionType::get(Builder.getInt32Ty(), ...