//===- Hello.cpp - Example code from "Writing an LLVM Pass" ---------------===// // // The LLVM Compiler Infrastructure // // This file was developed by the LLVM research group and is distributed under // the University of Illinois Open Source License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file implements two versions of the LLVM "Hello World" pass described // in docs/WritingAnLLVMPass.html // //===----------------------------------------------------------------------===// #include "llvm/Pass.h" #include "llvm/Function.h" #include <iostream> using namespace llvm; namespace { // Hello - The first implementation, without getAnalysisUsage. struct Hello : public FunctionPass { virtual bool runOnFunction(Function &F) { std::cerr << "Hello: " << F.getName() << "\n"; return false; } }; RegisterOpt<Hello> X("hello", "Hello World Pass"); // Hello2 - The second implementation with getAnalysisUsage implemented. struct Hello2 : public FunctionPass { virtual bool runOnFunction(Function &F) { std::cerr << "Hello: " << F.getName() << "\n"; return false; } // We don't modify the program, so we preserve all analyses virtual void getAnalysisUsage(AnalysisUsage &AU) const { AU.setPreservesAll(); }; }; RegisterOpt<Hello2> Y("hello2", "Hello World Pass (with getAnalysisUsage implemented)"); }