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//===-- UnifyFunctionExitNodes.h - Ensure fn's have one return --*- C++ -*-===//
// The LLVM Compiler Infrastructure
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
// This pass is used to ensure that functions have at most one return and one
// unwind instruction in them. Additionally, it keeps track of which node is
// the new exit node of the CFG. If there are no return or unwind instructions
// in the function, the getReturnBlock/getUnwindBlock methods will return a null
// pointer.
#include "llvm/Pass.h"
namespace llvm {
struct UnifyFunctionExitNodes : public FunctionPass {
BasicBlock *ReturnBlock, *UnwindBlock, *UnreachableBlock;
static char ID; // Pass identification, replacement for typeid
UnifyFunctionExitNodes() : FunctionPass(ID),
ReturnBlock(nullptr), UnwindBlock(nullptr) {
// We can preserve non-critical-edgeness when we unify function exit nodes
void getAnalysisUsage(AnalysisUsage &AU) const override;
// getReturn|Unwind|UnreachableBlock - Return the new single (or nonexistent)
// return, unwind, or unreachable basic blocks in the CFG.
BasicBlock *getReturnBlock() const { return ReturnBlock; }
BasicBlock *getUnwindBlock() const { return UnwindBlock; }
BasicBlock *getUnreachableBlock() const { return UnreachableBlock; }
bool runOnFunction(Function &F) override;
Pass *createUnifyFunctionExitNodesPass();
} // End llvm namespace