llvm/llvm/include/llvm/Support/CFGDiff.h

//===- CFGDiff.h - Define a CFG snapshot. -----------------------*- 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
//
//===----------------------------------------------------------------------===//
//
// This file defines specializations of GraphTraits that allows generic
// algorithms to see a different snapshot of a CFG.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_SUPPORT_CFGDIFF_H
#define LLVM_SUPPORT_CFGDIFF_H

#include "llvm/ADT/GraphTraits.h"
#include "llvm/ADT/iterator.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/Support/CFGUpdate.h"
#include "llvm/Support/type_traits.h"
#include <cassert>
#include <cstddef>
#include <iterator>

// Two booleans are used to define orders in graphs:
// InverseGraph defines when we need to reverse the whole graph and is as such
// also equivalent to applying updates in reverse.
// InverseEdge defines whether we want to change the edges direction. E.g., for
// a non-inversed graph, the children are naturally the successors when
// InverseEdge is false and the predecessors when InverseEdge is true.

namespace llvm {

namespace detail {
template <typename Range>
auto reverse_if_helper(Range &&R, std::integral_constant<bool, false>) { … }

template <typename Range>
auto reverse_if_helper(Range &&R, std::integral_constant<bool, true>) { … }

template <bool B, typename Range> auto reverse_if(Range &&R) { … }
} // namespace detail

// GraphDiff defines a CFG snapshot: given a set of Update<NodePtr>, provides
// a getChildren method to get a Node's children based on the additional updates
// in the snapshot. The current diff treats the CFG as a graph rather than a
// multigraph. Added edges are pruned to be unique, and deleted edges will
// remove all existing edges between two blocks.
template <typename NodePtr, bool InverseGraph = false> class GraphDiff { … };
} // end namespace llvm

#endif // LLVM_SUPPORT_CFGDIFF_H