//===- DeclLookups.h - Low-level interface to all names in a DC -*- 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

//

//===----------------------------------------------------------------------===//

//

//  This file defines DeclContext::all_lookups_iterator.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_AST_DECLLOOKUPS_H

#define LLVM_CLANG_AST_DECLLOOKUPS_H

#include "clang/AST/ASTContext.h"

#include "clang/AST/DeclBase.h"

#include "clang/AST/DeclContextInternals.h"

#include "clang/AST/DeclarationName.h"

#include "clang/AST/ExternalASTSource.h"

#include <cstddef>

#include <iterator>

namespace clang {

/// all_lookups_iterator - An iterator that provides a view over the results

/// of looking up every possible name.

class DeclContext::all_lookups_iterator {

  StoredDeclsMap::iterator It, End;

public:

  using value_type = lookup_result;

  using reference = lookup_result;

  using pointer = lookup_result;

  using iterator_category = std::forward_iterator_tag;

  using difference_type = std::ptrdiff_t;

  all_lookups_iterator() = default;

  all_lookups_iterator(StoredDeclsMap::iterator It,

                       StoredDeclsMap::iterator End)

      : It(It), End(End) {}

  DeclarationName getLookupName() const { return It->first; }

  reference operator*() const { return It->second.getLookupResult(); }

  pointer operator->() const { return It->second.getLookupResult(); }

  all_lookups_iterator& operator++() {

    // Filter out using directives. They don't belong as results from name

    // lookup anyways, except as an implementation detail. Users of the API

    // should not expect to get them (or worse, rely on it).

    do {

      ++It;

    } while (It != End &&

             It->first == DeclarationName::getUsingDirectiveName());

    return *this;

  }

  all_lookups_iterator operator++(int) {

    all_lookups_iterator tmp(*this);

    ++(*this);

    return tmp;

  }

  friend bool operator==(all_lookups_iterator x, all_lookups_iterator y) {

    return x.It == y.It;

  }

  friend bool operator!=(all_lookups_iterator x, all_lookups_iterator y) {

    return x.It != y.It;

  }

};

inline DeclContext::lookups_range DeclContext::lookups() const {

  DeclContext *Primary = const_cast<DeclContext*>(this)->getPrimaryContext();

  if (Primary->hasExternalVisibleStorage())

    getParentASTContext().getExternalSource()->completeVisibleDeclsMap(Primary);

  if (StoredDeclsMap *Map = Primary->buildLookup())

    return lookups_range(all_lookups_iterator(Map->begin(), Map->end()),

                         all_lookups_iterator(Map->end(), Map->end()));

  // Synthesize an empty range. This requires that two default constructed

  // versions of these iterators form a valid empty range.

  return lookups_range(all_lookups_iterator(), all_lookups_iterator());

}

inline DeclContext::lookups_range

DeclContext::noload_lookups(bool PreserveInternalState) const {

  DeclContext *Primary = const_cast<DeclContext*>(this)->getPrimaryContext();

  if (!PreserveInternalState)

    Primary->loadLazyLocalLexicalLookups();

  if (StoredDeclsMap *Map = Primary->getLookupPtr())

    return lookups_range(all_lookups_iterator(Map->begin(), Map->end()),

                         all_lookups_iterator(Map->end(), Map->end()));

  // Synthesize an empty range. This requires that two default constructed

  // versions of these iterators form a valid empty range.

  return lookups_range(all_lookups_iterator(), all_lookups_iterator());

}

} // namespace clang

#endif // LLVM_CLANG_AST_DECLLOOKUPS_H