llvm/llvm/include/llvm/XRay/Graph.h

//===-- Graph.h - XRay Graph Class ------------------------------*- 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
//
//===----------------------------------------------------------------------===//
//
// A Graph Datatype for XRay.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_XRAY_GRAPH_H
#define LLVM_XRAY_GRAPH_H

#include <initializer_list>
#include <stdint.h>
#include <type_traits>
#include <utility>

#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/iterator.h"
#include "llvm/Support/Error.h"

namespace llvm {
namespace xray {

/// A Graph object represents a Directed Graph and is used in XRay to compute
/// and store function call graphs and associated statistical information.
///
/// The graph takes in four template parameters, these are:
///  - VertexAttribute, this is a structure which is stored for each vertex.
///    Must be DefaultConstructible, CopyConstructible, CopyAssignable and
///    Destructible.
///  - EdgeAttribute, this is a structure which is stored for each edge
///    Must be DefaultConstructible, CopyConstructible, CopyAssignable and
///    Destructible.
///  - EdgeAttribute, this is a structure which is stored for each variable
///  - VI, this is a type over which DenseMapInfo is defined and is the type
///    used look up strings, available as VertexIdentifier.
///  - If the built in DenseMapInfo is not defined, provide a specialization
///    class type here.
///
/// Graph is CopyConstructible, CopyAssignable, MoveConstructible and
/// MoveAssignable but is not EqualityComparible or LessThanComparible.
///
/// Usage Example Graph with weighted edges and vertices:
///   Graph<int, int, int> G;
///
///   G[1] = 0;
///   G[2] = 2;
///   G[{1,2}] = 1;
///   G[{2,1}] = -1;
///   for(const auto &v : G.vertices()){
///     // Do something with the vertices in the graph;
///   }
///   for(const auto &e : G.edges()){
///     // Do something with the edges in the graph;
///   }
///
/// Usage Example with StrRef keys.
///   Graph<int, double, StrRef> StrG;
///    char va[] = "Vertex A";
///    char vaa[] = "Vertex A";
///    char vb[] = "Vertex B"; // Vertices are referenced by String Refs.
///    G[va] = 0;
///    G[vb] = 1;
///    G[{va, vb}] = 1.0;
///    cout() << G[vaa] << " " << G[{vaa, vb}]; //prints "0 1.0".
///
template <typename VertexAttribute, typename EdgeAttribute,
          typename VI = int32_t>
class Graph { … };
}
}
#endif