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