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      1 //===- DeclLookups.h - Low-level interface to all names in a DC -*- C++ -*-===//
      2 //
      3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
      4 // See https://llvm.org/LICENSE.txt for license information.
      5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
      6 //
      7 //===----------------------------------------------------------------------===//
      8 //
      9 //  This file defines DeclContext::all_lookups_iterator.
     10 //
     11 //===----------------------------------------------------------------------===//
     12 
     13 #ifndef LLVM_CLANG_AST_DECLLOOKUPS_H
     14 #define LLVM_CLANG_AST_DECLLOOKUPS_H
     15 
     16 #include "clang/AST/ASTContext.h"
     17 #include "clang/AST/DeclBase.h"
     18 #include "clang/AST/DeclContextInternals.h"
     19 #include "clang/AST/DeclarationName.h"
     20 #include "clang/AST/ExternalASTSource.h"
     21 #include <cstddef>
     22 #include <iterator>
     23 
     24 namespace clang {
     25 
     26 /// all_lookups_iterator - An iterator that provides a view over the results
     27 /// of looking up every possible name.
     28 class DeclContext::all_lookups_iterator {
     29   StoredDeclsMap::iterator It, End;
     30 
     31 public:
     32   using value_type = lookup_result;
     33   using reference = lookup_result;
     34   using pointer = lookup_result;
     35   using iterator_category = std::forward_iterator_tag;
     36   using difference_type = std::ptrdiff_t;
     37 
     38   all_lookups_iterator() = default;
     39   all_lookups_iterator(StoredDeclsMap::iterator It,
     40                        StoredDeclsMap::iterator End)
     41       : It(It), End(End) {}
     42 
     43   DeclarationName getLookupName() const { return It->first; }
     44 
     45   reference operator*() const { return It->second.getLookupResult(); }
     46   pointer operator->() const { return It->second.getLookupResult(); }
     47 
     48   all_lookups_iterator& operator++() {
     49     // Filter out using directives. They don't belong as results from name
     50     // lookup anyways, except as an implementation detail. Users of the API
     51     // should not expect to get them (or worse, rely on it).
     52     do {
     53       ++It;
     54     } while (It != End &&
     55              It->first == DeclarationName::getUsingDirectiveName());
     56 
     57     return *this;
     58   }
     59 
     60   all_lookups_iterator operator++(int) {
     61     all_lookups_iterator tmp(*this);
     62     ++(*this);
     63     return tmp;
     64   }
     65 
     66   friend bool operator==(all_lookups_iterator x, all_lookups_iterator y) {
     67     return x.It == y.It;
     68   }
     69 
     70   friend bool operator!=(all_lookups_iterator x, all_lookups_iterator y) {
     71     return x.It != y.It;
     72   }
     73 };
     74 
     75 inline DeclContext::lookups_range DeclContext::lookups() const {
     76   DeclContext *Primary = const_cast<DeclContext*>(this)->getPrimaryContext();
     77   if (Primary->hasExternalVisibleStorage())
     78     getParentASTContext().getExternalSource()->completeVisibleDeclsMap(Primary);
     79   if (StoredDeclsMap *Map = Primary->buildLookup())
     80     return lookups_range(all_lookups_iterator(Map->begin(), Map->end()),
     81                          all_lookups_iterator(Map->end(), Map->end()));
     82 
     83   // Synthesize an empty range. This requires that two default constructed
     84   // versions of these iterators form a valid empty range.
     85   return lookups_range(all_lookups_iterator(), all_lookups_iterator());
     86 }
     87 
     88 inline DeclContext::lookups_range
     89 DeclContext::noload_lookups(bool PreserveInternalState) const {
     90   DeclContext *Primary = const_cast<DeclContext*>(this)->getPrimaryContext();
     91   if (!PreserveInternalState)
     92     Primary->loadLazyLocalLexicalLookups();
     93   if (StoredDeclsMap *Map = Primary->getLookupPtr())
     94     return lookups_range(all_lookups_iterator(Map->begin(), Map->end()),
     95                          all_lookups_iterator(Map->end(), Map->end()));
     96 
     97   // Synthesize an empty range. This requires that two default constructed
     98   // versions of these iterators form a valid empty range.
     99   return lookups_range(all_lookups_iterator(), all_lookups_iterator());
    100 }
    101 
    102 } // namespace clang
    103 
    104 #endif // LLVM_CLANG_AST_DECLLOOKUPS_H
    105