EscapeEnumerator.h

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//===-- EscapeEnumerator.h --------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Defines a helper class that enumerates all possible exits from a function,
// including exception handling.
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_TRANSFORMS_UTILS_ESCAPEENUMERATOR_H
#define LLVM_TRANSFORMS_UTILS_ESCAPEENUMERATOR_H
 
#include "llvm/IR/Function.h"
#include "llvm/IR/IRBuilder.h"
 
namespace llvm {
 
class DomTreeUpdater;
 
/// EscapeEnumerator - This is a little algorithm to find all escape points
/// from a function so that "finally"-style code can be inserted. In addition
/// to finding the existing return and unwind instructions, it also (if
/// necessary) transforms any call instructions into invokes and sends them to
/// a landing pad.
class EscapeEnumerator {
  Function &F;
  const char *CleanupBBName;
 
  Function::iterator StateBB, StateE;
  IRBuilder<> Builder;
  bool Done = false;
  bool HandleExceptions;
 
  DomTreeUpdater *DTU;
 
public:
  EscapeEnumerator(Function &F, const char *N = "cleanup",
                   bool HandleExceptions = true, DomTreeUpdater *DTU = nullptr)
      : F(F), CleanupBBName(N), StateBB(F.begin()), StateE(F.end()),
        Builder(F.getContext()), HandleExceptions(HandleExceptions), DTU(DTU) {}
 
  IRBuilder<> *Next();
};
 
}
 
#endif // LLVM_TRANSFORMS_UTILS_ESCAPEENUMERATOR_H