FormattersContainer.h

Go to the documentation of this file.

//===-- FormattersContainer.h -----------------------------------*- 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
//
//===----------------------------------------------------------------------===//

#ifndef LLDB_DATAFORMATTERS_FORMATTERSCONTAINER_H
#define LLDB_DATAFORMATTERS_FORMATTERSCONTAINER_H

#include <functional>
#include <map>
#include <memory>
#include <mutex>
#include <string>

#include "lldb/lldb-public.h"

#include "lldb/Core/ValueObject.h"
#include "lldb/DataFormatters/FormatClasses.h"
#include "lldb/DataFormatters/TypeFormat.h"
#include "lldb/DataFormatters/TypeSummary.h"
#include "lldb/DataFormatters/TypeSynthetic.h"
#include "lldb/Symbol/CompilerType.h"
#include "lldb/Utility/RegularExpression.h"
#include "lldb/Utility/StringLexer.h"

namespace lldb_private {

class IFormatChangeListener {
public:
  virtual ~IFormatChangeListener() = default;

  virtual void Changed() = 0;

  virtual uint32_t GetCurrentRevision() = 0;
};

// if the user tries to add formatters for, say, "struct Foo" those will not
// match any type because of the way we strip qualifiers from typenames this
// method looks for the case where the user is adding a "class","struct","enum"
// or "union" Foo and strips the unnecessary qualifier
static inline ConstString GetValidTypeName_Impl(ConstString type) {
  if (type.IsEmpty())
    return type;

  std::string type_cstr(type.AsCString());
  StringLexer type_lexer(type_cstr);

  type_lexer.AdvanceIf("class ");
  type_lexer.AdvanceIf("enum ");
  type_lexer.AdvanceIf("struct ");
  type_lexer.AdvanceIf("union ");

  while (type_lexer.NextIf({' ', '\t', '\v', '\f'}).first)
    ;

  return ConstString(type_lexer.GetUnlexed());
}

template <typename KeyType, typename ValueType> class FormattersContainer;

template <typename KeyType, typename ValueType> class FormatMap {
public:
  typedef typename ValueType::SharedPointer ValueSP;
  typedef std::vector<std::pair<KeyType, ValueSP>> MapType;
  typedef typename MapType::iterator MapIterator;
  typedef std::function<bool(const KeyType &, const ValueSP &)> ForEachCallback;

  FormatMap(IFormatChangeListener *lst)
      : m_map(), m_map_mutex(), listener(lst) {}

  void Add(KeyType name, const ValueSP &entry) {
    if (listener)
      entry->GetRevision() = listener->GetCurrentRevision();
    else
      entry->GetRevision() = 0;

    std::lock_guard<std::recursive_mutex> guard(m_map_mutex);
    Delete(name);
    m_map.emplace_back(std::move(name), std::move(entry));
    if (listener)
      listener->Changed();
  }

  bool Delete(const KeyType &name) {
    std::lock_guard<std::recursive_mutex> guard(m_map_mutex);
    for (MapIterator iter = m_map.begin(); iter != m_map.end(); ++iter)
      if (iter->first == name) {
        m_map.erase(iter);
        if (listener)
          listener->Changed();
        return true;
      }
    return false;
  }

  void Clear() {
    std::lock_guard<std::recursive_mutex> guard(m_map_mutex);
    m_map.clear();
    if (listener)
      listener->Changed();
  }

  bool Get(const KeyType &name, ValueSP &entry) {
    std::lock_guard<std::recursive_mutex> guard(m_map_mutex);
    for (const auto &pos : m_map)
      if (pos.first == name) {
        entry = pos.second;
        return true;
      }
    return false;
  }

  void ForEach(ForEachCallback callback) {
    if (callback) {
      std::lock_guard<std::recursive_mutex> guard(m_map_mutex);
      for (const auto &pos : m_map) {
        const KeyType &type = pos.first;
        if (!callback(type, pos.second))
          break;
      }
    }
  }

  uint32_t GetCount() { return m_map.size(); }

  ValueSP GetValueAtIndex(size_t index) {
    std::lock_guard<std::recursive_mutex> guard(m_map_mutex);
    if (index >= m_map.size())
      return ValueSP();
    return m_map[index].second;
  }

  // If caller holds the mutex we could return a reference without copy ctor.
  KeyType GetKeyAtIndex(size_t index) {
    std::lock_guard<std::recursive_mutex> guard(m_map_mutex);
    if (index >= m_map.size())
      return {};
    return m_map[index].first;
  }

protected:
  MapType m_map;
  std::recursive_mutex m_map_mutex;
  IFormatChangeListener *listener;

  MapType &map() { return m_map; }

  std::recursive_mutex &mutex() { return m_map_mutex; }

  friend class FormattersContainer<KeyType, ValueType>;
  friend class FormatManager;
};

template <typename KeyType, typename ValueType> class FormattersContainer {
protected:
  typedef FormatMap<KeyType, ValueType> BackEndType;

public:
  typedef typename BackEndType::MapType MapType;
  typedef typename MapType::iterator MapIterator;
  typedef KeyType MapKeyType;
  typedef std::shared_ptr<ValueType> MapValueType;
  typedef typename BackEndType::ForEachCallback ForEachCallback;
  typedef typename std::shared_ptr<FormattersContainer<KeyType, ValueType>>
      SharedPointer;

  friend class TypeCategoryImpl;

  FormattersContainer(std::string name, IFormatChangeListener *lst)
      : m_format_map(lst), m_name(name) {}

  void Add(MapKeyType type, const MapValueType &entry) {
    Add_Impl(std::move(type), entry, static_cast<KeyType *>(nullptr));
  }

  bool Delete(ConstString type) {
    return Delete_Impl(type, static_cast<KeyType *>(nullptr));
  }

  bool Get(ValueObject &valobj, MapValueType &entry,
           lldb::DynamicValueType use_dynamic) {
    CompilerType ast_type(valobj.GetCompilerType());
    bool ret = Get(valobj, ast_type, entry, use_dynamic);
    if (ret)
      entry = MapValueType(entry);
    else
      entry = MapValueType();
    return ret;
  }

  bool Get(ConstString type, MapValueType &entry) {
    return Get_Impl(type, entry, static_cast<KeyType *>(nullptr));
  }

  bool GetExact(ConstString type, MapValueType &entry) {
    return GetExact_Impl(type, entry, static_cast<KeyType *>(nullptr));
  }

  MapValueType GetAtIndex(size_t index) {
    return m_format_map.GetValueAtIndex(index);
  }

  lldb::TypeNameSpecifierImplSP GetTypeNameSpecifierAtIndex(size_t index) {
    return GetTypeNameSpecifierAtIndex_Impl(index,
                                            static_cast<KeyType *>(nullptr));
  }

  void Clear() { m_format_map.Clear(); }

  void ForEach(ForEachCallback callback) { m_format_map.ForEach(callback); }

  uint32_t GetCount() { return m_format_map.GetCount(); }

protected:
  BackEndType m_format_map;
  std::string m_name;

  FormattersContainer(const FormattersContainer &) = delete;
  const FormattersContainer &operator=(const FormattersContainer &) = delete;

  void Add_Impl(MapKeyType type, const MapValueType &entry,
                RegularExpression *dummy) {
    m_format_map.Add(std::move(type), entry);
  }

  void Add_Impl(ConstString type, const MapValueType &entry,
                ConstString *dummy) {
    m_format_map.Add(GetValidTypeName_Impl(type), entry);
  }

  bool Delete_Impl(ConstString type, ConstString *dummy) {
    return m_format_map.Delete(type);
  }

  bool Delete_Impl(ConstString type, RegularExpression *dummy) {
    std::lock_guard<std::recursive_mutex> guard(m_format_map.mutex());
    MapIterator pos, end = m_format_map.map().end();
    for (pos = m_format_map.map().begin(); pos != end; pos++) {
      const RegularExpression &regex = pos->first;
      if (type.GetStringRef() == regex.GetText()) {
        m_format_map.map().erase(pos);
        if (m_format_map.listener)
          m_format_map.listener->Changed();
        return true;
      }
    }
    return false;
  }

  bool Get_Impl(ConstString type, MapValueType &entry, ConstString *dummy) {
    return m_format_map.Get(type, entry);
  }

  bool GetExact_Impl(ConstString type, MapValueType &entry,
                     ConstString *dummy) {
    return Get_Impl(type, entry, static_cast<KeyType *>(nullptr));
  }

  lldb::TypeNameSpecifierImplSP
  GetTypeNameSpecifierAtIndex_Impl(size_t index, ConstString *dummy) {
    ConstString key = m_format_map.GetKeyAtIndex(index);
    if (key)
      return lldb::TypeNameSpecifierImplSP(
          new TypeNameSpecifierImpl(key.GetStringRef(), false));
    else
      return lldb::TypeNameSpecifierImplSP();
  }

  lldb::TypeNameSpecifierImplSP
  GetTypeNameSpecifierAtIndex_Impl(size_t index, RegularExpression *dummy) {
    RegularExpression regex = m_format_map.GetKeyAtIndex(index);
    if (regex == RegularExpression())
      return lldb::TypeNameSpecifierImplSP();
    return lldb::TypeNameSpecifierImplSP(
        new TypeNameSpecifierImpl(regex.GetText().str().c_str(), true));
  }

  bool Get_Impl(ConstString key, MapValueType &value,
                RegularExpression *dummy) {
    llvm::StringRef key_str = key.GetStringRef();
    std::lock_guard<std::recursive_mutex> guard(m_format_map.mutex());
    // Patterns are matched in reverse-chronological order.
    for (const auto &pos : llvm::reverse(m_format_map.map())) {
      const RegularExpression &regex = pos.first;
      if (regex.Execute(key_str)) {
        value = pos.second;
        return true;
      }
    }
    return false;
  }

  bool GetExact_Impl(ConstString key, MapValueType &value,
                     RegularExpression *dummy) {
    std::lock_guard<std::recursive_mutex> guard(m_format_map.mutex());
    for (const auto &pos : m_format_map.map()) {
      const RegularExpression &regex = pos.first;
      if (regex.GetText() == key.GetStringRef()) {
        value = pos.second;
        return true;
      }
    }
    return false;
  }

  bool Get(const FormattersMatchVector &candidates, MapValueType &entry) {
    for (const FormattersMatchCandidate &candidate : candidates) {
      if (Get(candidate.GetTypeName(), entry)) {
        if (candidate.IsMatch(entry) == false) {
          entry.reset();
          continue;
        } else {
          return true;
        }
      }
    }
    return false;
  }
};

} // namespace lldb_private

#endif // LLDB_DATAFORMATTERS_FORMATTERSCONTAINER_H