deparse_graph.h

 
#ifndef BACKENDS_TOFINO_BF_P4C_PARDE_CLOT_DEPARSE_GRAPH_H_
#define BACKENDS_TOFINO_BF_P4C_PARDE_CLOT_DEPARSE_GRAPH_H_
 
#include "bf-p4c/lib/boost_graph.h"
#include "bf-p4c/phv/phv_fields.h"
 
// Declare a type and boost property for DeparseGraph vertices.
namespace boost {
enum vertex_deparse_graph_t { vertex_deparse_graph };
BOOST_INSTALL_PROPERTY(vertex, deparse_graph);
}  // namespace boost
 
class DeparseGraph {
 public:
    struct NodeInfo {
        const IR::Constant *constant;
 
        const PHV::Field *field;
 
        bool isConstant() const { return constant; }
        bool isField() const { return field; }
 
        // This seems to be required by Boost, but breaks the representation invariant that at
        // least one of @constant and @field is non-null. :(
        NodeInfo() : constant(nullptr), field(nullptr) {}
 
        explicit NodeInfo(const IR::Constant *constant) : constant(constant), field(nullptr) {
            BUG_CHECK(constant, "Created a deparse graph node with a null constant");
        }
 
        explicit NodeInfo(const PHV::Field *field) : constant(nullptr), field(field) {
            BUG_CHECK(field, "Created a deparse graph node with a null field");
        }
    };
 
 private:
    typedef boost::adjacency_list<boost::vecS, boost::vecS,
                                  boost::bidirectionalS,  // Directed edges.
                                  NodeInfo                // Label vertices with NodeInfo.
                                  >
        Graph;
 
 public:
    using Node = typename Graph::vertex_descriptor;
 
    Node addField(const PHV::Field *f);
 
    Node addConst(const IR::Constant *c);
 
    bool addEdge(Node src, Node dst);
 
    bool canReach(const PHV::Field *f1, const PHV::Field *f2) const;
 
    const std::vector<NodeInfo> nodesBetween(const PHV::Field *f1, const PHV::Field *f2) const;
 
    void clear();
 
 private:
    Graph g;
 
    ordered_set<const PHV::Field *> fields;
 
    std::map<const PHV::Field *, Node> fieldToVertex;
 
    mutable Reachability<Graph> reachability;
 
 public:
    DeparseGraph() : reachability(g) {}
};
 
#endif /* BACKENDS_TOFINO_BF_P4C_PARDE_CLOT_DEPARSE_GRAPH_H_ */