function_flow_graph_mdindex.h

// Copyright 2011-2024 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef MATCH_FUNCTION_FLOW_GRAPH_MDINDEX_H_
#define MATCH_FUNCTION_FLOW_GRAPH_MDINDEX_H_

#include "third_party/absl/strings/str_cat.h"
#include "third_party/zynamics/bindiff/match/call_graph.h"

namespace security::bindiff {

// Matches functions based on their structure using the MD index. Since the MD
// index takes a topological graph ordering as one of it's inputs we can
// parametrize it by whether we sort the graph vertices into levels following
// calls from the entrypoint (top down) or callers from the exit points (bottom
// up).
class MatchingStepFlowGraphMdIndex : public MatchingStep {
 public:
  explicit MatchingStepFlowGraphMdIndex(Direction direction)
      : MatchingStep(
            absl::StrCat("function: MD index matching (flowgraph MD index, ",
                         direction == kTopDown ? "top down)" : "bottom up)"),
            absl::StrCat("Function: MD Index (Flow Graph MD Index, ",
                         direction == kTopDown ? "Top Down)" : "Bottom Up)")),
        direction_(direction) {}

  bool FindFixedPoints(const FlowGraph* primary_parent,
                       const FlowGraph* secondary_parent,
                       FlowGraphs& flow_graphs_1, FlowGraphs& flow_graphs_2,
                       MatchingContext& context, MatchingSteps& matching_steps,
                       const MatchingStepsFlowGraph& default_steps) override;

 private:
  void GetUnmatchedFlowGraphsByMdIndex(const FlowGraphs& flow_graphs,
                                       FlowGraphDoubleMap& flow_graphs_map);
  Direction direction_;
};

}  // namespace security::bindiff

#endif  // MATCH_FUNCTION_FLOW_GRAPH_MDINDEX_H_