1//===- UnresolvedSet.h - Unresolved sets of declarations --------*- 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 the UnresolvedSet class, which is used to store
10//  collections of declarations in the AST.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_AST_UNRESOLVEDSET_H
15#define LLVM_CLANG_AST_UNRESOLVEDSET_H
16
17#include "clang/AST/DeclAccessPair.h"
18#include "clang/Basic/LLVM.h"
19#include "clang/Basic/Specifiers.h"
20#include "llvm/ADT/ArrayRef.h"
21#include "llvm/ADT/SmallVector.h"
22#include "llvm/ADT/iterator.h"
23#include <cstddef>
24#include <iterator>
25
26namespace clang {
27
28class NamedDecl;
29
30/// The iterator over UnresolvedSets.  Serves as both the const and
31/// non-const iterator.
32class UnresolvedSetIterator : public llvm::iterator_adaptor_base<
33                                  UnresolvedSetIterator, DeclAccessPair *,
34                                  std::random_access_iterator_tag, NamedDecl *,
35                                  std::ptrdiff_t, NamedDecl *, NamedDecl *> {
36  friend class ASTUnresolvedSet;
37  friend class OverloadExpr;
38  friend class UnresolvedSetImpl;
39
40  explicit UnresolvedSetIterator(DeclAccessPair *Iter)
41      : iterator_adaptor_base(Iter) {}
42  explicit UnresolvedSetIterator(const DeclAccessPair *Iter)
43      : iterator_adaptor_base(const_cast<DeclAccessPair *>(Iter)) {}
44
45public:
46  // Work around a bug in MSVC 2013 where explicitly default constructed
47  // temporaries with defaulted ctors are not zero initialized.
48  UnresolvedSetIterator() : iterator_adaptor_base(nullptr) {}
49
50  NamedDecl *getDecl() const { return I->getDecl(); }
51  void setDecl(NamedDecl *ND) const { return I->setDecl(ND); }
52  AccessSpecifier getAccess() const { return I->getAccess(); }
53  void setAccess(AccessSpecifier AS) { I->setAccess(AS); }
54  const DeclAccessPair &getPair() const { return *I; }
55
56  NamedDecl *operator*() const { return getDecl(); }
57  NamedDecl *operator->() const { return **this; }
58};
59
60/// A set of unresolved declarations.
61class UnresolvedSetImpl {
62  using DeclsTy = SmallVectorImpl<DeclAccessPair>;
63
64  // Don't allow direct construction, and only permit subclassing by
65  // UnresolvedSet.
66private:
67  template <unsigned N> friend class UnresolvedSet;
68
69  UnresolvedSetImpl() = default;
70  UnresolvedSetImpl(const UnresolvedSetImpl &) = default;
71  UnresolvedSetImpl &operator=(const UnresolvedSetImpl &) = default;
72
73  // FIXME: Switch these to "= default" once MSVC supports generating move ops
74  UnresolvedSetImpl(UnresolvedSetImpl &&) {}
75  UnresolvedSetImpl &operator=(UnresolvedSetImpl &&) { return *this; }
76
77public:
78  // We don't currently support assignment through this iterator, so we might
79  // as well use the same implementation twice.
80  using iterator = UnresolvedSetIterator;
81  using const_iterator = UnresolvedSetIterator;
82
83  iterator begin() { return iterator(decls().begin()); }
84  iterator end() { return iterator(decls().end()); }
85
86  const_iterator begin() const { return const_iterator(decls().begin()); }
87  const_iterator end() const { return const_iterator(decls().end()); }
88
89  ArrayRef<DeclAccessPair> pairs() const { return decls(); }
90
91  void addDecl(NamedDecl *D) {
92    addDecl(D, AS_none);
93  }
94
95  void addDecl(NamedDecl *D, AccessSpecifier AS) {
96    decls().push_back(DeclAccessPair::make(D, AS));
97  }
98
99  /// Replaces the given declaration with the new one, once.
100  ///
101  /// \return true if the set changed
102  bool replace(const NamedDecl* Old, NamedDecl *New) {
103    for (DeclsTy::iterator I = decls().begin(), E = decls().end(); I != E; ++I)
104      if (I->getDecl() == Old)
105        return (I->setDecl(New), true);
106    return false;
107  }
108
109  /// Replaces the declaration at the given iterator with the new one,
110  /// preserving the original access bits.
111  void replace(iterator I, NamedDecl *New) { I.I->setDecl(New); }
112
113  void replace(iterator I, NamedDecl *New, AccessSpecifier AS) {
114    I.I->set(New, AS);
115  }
116
117  void erase(unsigned I) { decls()[I] = decls().pop_back_val(); }
118
119  void erase(iterator I) { *I.I = decls().pop_back_val(); }
120
121  void setAccess(iterator I, AccessSpecifier AS) { I.I->setAccess(AS); }
122
123  void clear() { decls().clear(); }
124  void set_size(unsigned N) { decls().set_size(N); }
125
126  bool empty() const { return decls().empty(); }
127  unsigned size() const { return decls().size(); }
128
129  void append(iterator I, iterator E) { decls().append(I.I, E.I); }
130
131  template<typename Iter> void assign(Iter I, Iter E) { decls().assign(I, E); }
132
133  DeclAccessPair &operator[](unsigned I) { return decls()[I]; }
134  const DeclAccessPair &operator[](unsigned I) const { return decls()[I]; }
135
136private:
137  // These work because the only permitted subclass is UnresolvedSetImpl
138
139  DeclsTy &decls() {
140    return *reinterpret_cast<DeclsTy*>(this);
141  }
142  const DeclsTy &decls() const {
143    return *reinterpret_cast<const DeclsTy*>(this);
144  }
145};
146
147/// A set of unresolved declarations.
148template <unsigned InlineCapacity> class UnresolvedSet :
149    public UnresolvedSetImpl {
150  SmallVector<DeclAccessPair, InlineCapacity> Decls;
151};
152
153
154} // namespace clang
155
156#endif // LLVM_CLANG_AST_UNRESOLVEDSET_H
157