: //===- examples/ModuleMaker/ModuleMaker.cpp - Example project ---*- C++ -*-===//

: //

: //                     The LLVM Compiler Infrastructure

: //

: // This file is distributed under the University of Illinois Open Source

: // License. See LICENSE.TXT for details.

: //

: //===----------------------------------------------------------------------===//

: //

: // This programs is a simple example that creates an LLVM module "from scratch",

: // emitting it as a bitcode file to standard out.  This is just to show how

: // LLVM projects work and to demonstrate some of the LLVM APIs.

: //

: //===----------------------------------------------------------------------===//

: 

: #include "llvm/Bitcode/ReaderWriter.h"

: #include "llvm/IR/Constants.h"

: #include "llvm/IR/DerivedTypes.h"

: #include "llvm/IR/Instructions.h"

: #include "llvm/IR/LLVMContext.h"

: #include "llvm/IR/Module.h"

: #include "llvm/Support/raw_ostream.h"

: using namespace llvm;

: 

: int main() {

:   LLVMContext Context;

: 

:   // Create the "module" or "program" or "translation unit" to hold the

:   // function

:   Module *M = new Module("test", Context);

: 

:   // Create the main function: first create the type 'int ()'

:   FunctionType *FT =

:     FunctionType::get(Type::getInt32Ty(Context), /*not vararg*/false);

: 

:   // By passing a module as the last parameter to the Function constructor,

:   // it automatically gets appended to the Module.

:   Function *F = Function::Create(FT, Function::ExternalLinkage, "main", M);

: 

:   // Add a basic block to the function... again, it automatically inserts

:   // because of the last argument.

:   BasicBlock *BB = BasicBlock::Create(Context, "EntryBlock", F);

: 

:   // Get pointers to the constant integers...

:   Value *Two = ConstantInt::get(Type::getInt32Ty(Context), 2);

:   Value *Three = ConstantInt::get(Type::getInt32Ty(Context), 3);

: 

:   // Create the add instruction... does not insert...

:   Instruction *Add = BinaryOperator::Create(Instruction::Add, Two, Three,

:                                             "addresult");

: 

:   // explicitly insert it into the basic block...

:   BB->getInstList().push_back(Add);

: 

:   // Create the return instruction and add it to the basic block

:   BB->getInstList().push_back(ReturnInst::Create(Context, Add));

: 

:   // Output the bitcode file to stdout

:   WriteBitcodeToFile(M, outs());

: 

:   // Delete the module and all of its contents.

:   delete M;

:   return 0;

: }