Now that we have created a module, the next step is to emit a function. LLVM has an IRBuilder class that is used to generate LLVM IR and print it using the dump function of the Module object. LLVM provides the class llvm::Function to create a function and llvm::FunctionType() to associate a return type for the function. Let's assume that our foo() function returns an integer type.
Function *createFunc(IRBuilder<> &Builder, std::string Name) {
FunctionType *funcType = llvm::FunctionType::get(Builder.getInt32Ty(), false);
Function *fooFunc = llvm::Function::Create(
funcType, llvm::Function::ExternalLinkage, Name, ModuleOb);
return fooFunc;
}Finally, call function verifyFunction() on fooFunc. This function performs a variety of consistency checks on the generated code, to determine if our compiler is doing everything right.
int main(int argc, char *argv[]) {
static IRBuilder<> Builder(Context);
Function *fooFunc = createFunc(Builder...