Hello.cpp revision fd93908ae8b9684fe71c239e3c6cfe13ff6a2663
1180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner//===- Hello.cpp - Example code from "Writing an LLVM Pass" ---------------===// 2fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman// 3b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell// The LLVM Compiler Infrastructure 4b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell// 5b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell// This file was developed by the LLVM research group and is distributed under 6b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell// the University of Illinois Open Source License. See LICENSE.TXT for details. 7fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman// 8b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell//===----------------------------------------------------------------------===// 9180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner// 10180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner// This file implements two versions of the LLVM "Hello World" pass described 11180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner// in docs/WritingAnLLVMPass.html 12180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner// 13180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner//===----------------------------------------------------------------------===// 14180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner 15180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner#include "llvm/Pass.h" 16180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner#include "llvm/Function.h" 17a5de823844dc2194ea2fc69359ded9848d6cb6e5Chris Lattner#include <iostream> 18f7703df4968084c18c248c1feea9961c19a32e6aChris Lattnerusing namespace llvm; 19d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 20180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattnernamespace { 21180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner // Hello - The first implementation, without getAnalysisUsage. 22180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner struct Hello : public FunctionPass { 23180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner virtual bool runOnFunction(Function &F) { 24180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner std::cerr << "Hello: " << F.getName() << "\n"; 25180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner return false; 26180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner } 27fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman }; 28180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner RegisterOpt<Hello> X("hello", "Hello World Pass"); 29180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner 30180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner // Hello2 - The second implementation with getAnalysisUsage implemented. 31180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner struct Hello2 : public FunctionPass { 32180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner virtual bool runOnFunction(Function &F) { 33180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner std::cerr << "Hello: " << F.getName() << "\n"; 34180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner return false; 35180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner } 36180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner 37180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner // We don't modify the program, so we preserve all analyses 38180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner virtual void getAnalysisUsage(AnalysisUsage &AU) const { 39180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner AU.setPreservesAll(); 40180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner }; 41fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman }; 42180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner RegisterOpt<Hello2> Y("hello2", "Hello World Pass (with getAnalysisUsage implemented)"); 43180e568a70580e177cda71e354f6620aeaaa1b63Chris Lattner} 44