1//===-- UnifyFunctionExitNodes.h - Ensure fn's have one return --*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This pass is used to ensure that functions have at most one return and one 11// unwind instruction in them. Additionally, it keeps track of which node is 12// the new exit node of the CFG. If there are no return or unwind instructions 13// in the function, the getReturnBlock/getUnwindBlock methods will return a null 14// pointer. 15// 16//===----------------------------------------------------------------------===// 17 18#ifndef LLVM_TRANSFORMS_UNIFYFUNCTIONEXITNODES_H 19#define LLVM_TRANSFORMS_UNIFYFUNCTIONEXITNODES_H 20 21#include "llvm/Pass.h" 22 23namespace llvm { 24 25struct UnifyFunctionExitNodes : public FunctionPass { 26 BasicBlock *ReturnBlock, *UnwindBlock, *UnreachableBlock; 27public: 28 static char ID; // Pass identification, replacement for typeid 29 UnifyFunctionExitNodes() : FunctionPass(ID), 30 ReturnBlock(0), UnwindBlock(0) { 31 initializeUnifyFunctionExitNodesPass(*PassRegistry::getPassRegistry()); 32 } 33 34 // We can preserve non-critical-edgeness when we unify function exit nodes 35 virtual void getAnalysisUsage(AnalysisUsage &AU) const; 36 37 // getReturn|Unwind|UnreachableBlock - Return the new single (or nonexistent) 38 // return, unwind, or unreachable basic blocks in the CFG. 39 // 40 BasicBlock *getReturnBlock() const { return ReturnBlock; } 41 BasicBlock *getUnwindBlock() const { return UnwindBlock; } 42 BasicBlock *getUnreachableBlock() const { return UnreachableBlock; } 43 44 virtual bool runOnFunction(Function &F); 45}; 46 47Pass *createUnifyFunctionExitNodesPass(); 48 49} // End llvm namespace 50 51#endif 52