object-introspection/oi/type_graph/AddChildren.h
2023-07-26 18:01:38 +01:00

80 lines
2.3 KiB
C++

/*
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* 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
*
* http://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.
*/
#pragma once
#include <functional>
#include <unordered_set>
#include <vector>
#include "PassManager.h"
#include "Types.h"
#include "Visitor.h"
struct drgn_type;
namespace oi::detail {
class SymbolService;
}
namespace oi::detail::type_graph {
class DrgnParser;
class TypeGraph;
/*
* AddChildren
*
* Populates the "children" field of Class types.
*
* DWARF only stores a mapping of [child -> parent], but sometimes we want the
* invserse: [parent -> child]. We must iterate over every single type to build
* up our own inverse mapping, before applying it to the relevant type nodes.
*
* This is expensive and only useful for types which make use of dynamic
* inheritance hierarchies (e.g. polymorphism), so is not done as part of the
* standard DrgnParser stage.
*/
class AddChildren final : public RecursiveVisitor {
public:
static Pass createPass(DrgnParser& drgnParser, SymbolService& symbols);
AddChildren(TypeGraph& typeGraph, DrgnParser& drgnParser)
: typeGraph_(typeGraph), drgnParser_(drgnParser) {
}
using RecursiveVisitor::accept;
void accept(Type& type) override;
void visit(Class& c) override;
private:
void enumerateChildClasses(SymbolService& symbols);
void enumerateClassChildren(
struct drgn_type* type,
std::vector<std::reference_wrapper<Class>>& children);
void recordChildren(drgn_type* type);
std::unordered_set<Type*> visited_;
TypeGraph& typeGraph_;
DrgnParser& drgnParser_;
// Mapping of parent classes to child classes, using names for keys, as drgn
// pointers returned from a type iterator will not match those returned from
// enumerating types in the normal way.
std::unordered_map<std::string, std::vector<drgn_type*>> childClasses_;
};
} // namespace oi::detail::type_graph