trampoline_graph.h

// This file if part of the llir-opt project.
// Licensing information can be found in the LICENSE file.
// (C) 2018 Nandor Licker. All rights reserved.
 
#pragma once
 
#include <unordered_map>
#include <set>
#include <stack>
 
class Func;
class Prog;
class Value;
 
 
class TrampolineGraph final {
public:
  TrampolineGraph(const Prog *prog);
 
  bool NeedsTrampoline(ConstRef<Value> callee);
 
private:
 
  void BuildGraph(const Prog *prog);
 
  void Visit(const Func *func);
 
private:
  struct Node {
    std::set<const Func *> Out;
    unsigned Index = 0;
    unsigned LowLink = 0;
    bool OnStack = false;
    bool Trampoline = false;
  };
  std::unordered_map<const Func *, Node> graph_;
 
  unsigned index_ = 1;
  std::stack<const Func *> stack_;
};