| //===- 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 "llvm/ADT/StringExtras.h" |
| #include "llvm/Support/SlowOperationInformer.h" |
| #include "llvm/ADT/Statistic.h" |
| #include <iostream> |
| using namespace llvm; |
| |
| namespace { |
| Statistic<int> HelloCounter("hellocount", |
| "Counts number of functions greeted"); |
| // Hello - The first implementation, without getAnalysisUsage. |
| struct Hello : public FunctionPass { |
| virtual bool runOnFunction(Function &F) { |
| SlowOperationInformer soi("EscapeString"); |
| HelloCounter++; |
| std::string fname = F.getName(); |
| EscapeString(fname); |
| std::cerr << "Hello: " << fname << "\n"; |
| return false; |
| } |
| }; |
| RegisterPass<Hello> X("hello", "Hello World Pass"); |
| |
| // Hello2 - The second implementation with getAnalysisUsage implemented. |
| struct Hello2 : public FunctionPass { |
| virtual bool runOnFunction(Function &F) { |
| SlowOperationInformer soi("EscapeString"); |
| HelloCounter++; |
| std::string fname = F.getName(); |
| EscapeString(fname); |
| std::cerr << "Hello: " << fname << "\n"; |
| return false; |
| } |
| |
| // We don't modify the program, so we preserve all analyses |
| virtual void getAnalysisUsage(AnalysisUsage &AU) const { |
| AU.setPreservesAll(); |
| }; |
| }; |
| RegisterPass<Hello2> Y("hello2", |
| "Hello World Pass (with getAnalysisUsage implemented)"); |
| } |