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 
26 namespace clang {
27 
28 class NamedDecl;
29 
30 /// The iterator over UnresolvedSets.  Serves as both the const and
31 /// non-const iterator.
32 class 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 
UnresolvedSetIterator(DeclAccessPair * Iter)40   explicit UnresolvedSetIterator(DeclAccessPair *Iter)
41       : iterator_adaptor_base(Iter) {}
UnresolvedSetIterator(const DeclAccessPair * Iter)42   explicit UnresolvedSetIterator(const DeclAccessPair *Iter)
43       : iterator_adaptor_base(const_cast<DeclAccessPair *>(Iter)) {}
44 
45 public:
46   // Work around a bug in MSVC 2013 where explicitly default constructed
47   // temporaries with defaulted ctors are not zero initialized.
UnresolvedSetIterator()48   UnresolvedSetIterator() : iterator_adaptor_base(nullptr) {}
49 
getDecl()50   NamedDecl *getDecl() const { return I->getDecl(); }
setDecl(NamedDecl * ND)51   void setDecl(NamedDecl *ND) const { return I->setDecl(ND); }
getAccess()52   AccessSpecifier getAccess() const { return I->getAccess(); }
setAccess(AccessSpecifier AS)53   void setAccess(AccessSpecifier AS) { I->setAccess(AS); }
getPair()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.
61 class UnresolvedSetImpl {
62   using DeclsTy = SmallVectorImpl<DeclAccessPair>;
63 
64   // Don't allow direct construction, and only permit subclassing by
65   // UnresolvedSet.
66 private:
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
UnresolvedSetImpl(UnresolvedSetImpl &&)74   UnresolvedSetImpl(UnresolvedSetImpl &&) {}
75   UnresolvedSetImpl &operator=(UnresolvedSetImpl &&) { return *this; }
76 
77 public:
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 
begin()83   iterator begin() { return iterator(decls().begin()); }
end()84   iterator end() { return iterator(decls().end()); }
85 
begin()86   const_iterator begin() const { return const_iterator(decls().begin()); }
end()87   const_iterator end() const { return const_iterator(decls().end()); }
88 
pairs()89   ArrayRef<DeclAccessPair> pairs() const { return decls(); }
90 
addDecl(NamedDecl * D)91   void addDecl(NamedDecl *D) {
92     addDecl(D, AS_none);
93   }
94 
addDecl(NamedDecl * D,AccessSpecifier AS)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
replace(const NamedDecl * Old,NamedDecl * New)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.
replace(iterator I,NamedDecl * New)111   void replace(iterator I, NamedDecl *New) { I.I->setDecl(New); }
112 
replace(iterator I,NamedDecl * New,AccessSpecifier AS)113   void replace(iterator I, NamedDecl *New, AccessSpecifier AS) {
114     I.I->set(New, AS);
115   }
116 
erase(unsigned I)117   void erase(unsigned I) { decls()[I] = decls().pop_back_val(); }
118 
erase(iterator I)119   void erase(iterator I) { *I.I = decls().pop_back_val(); }
120 
setAccess(iterator I,AccessSpecifier AS)121   void setAccess(iterator I, AccessSpecifier AS) { I.I->setAccess(AS); }
122 
clear()123   void clear() { decls().clear(); }
set_size(unsigned N)124   void set_size(unsigned N) { decls().set_size(N); }
125 
empty()126   bool empty() const { return decls().empty(); }
size()127   unsigned size() const { return decls().size(); }
128 
append(iterator I,iterator E)129   void append(iterator I, iterator E) { decls().append(I.I, E.I); }
130 
assign(Iter I,Iter E)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 
136 private:
137   // These work because the only permitted subclass is UnresolvedSetImpl
138 
decls()139   DeclsTy &decls() {
140     return *reinterpret_cast<DeclsTy*>(this);
141   }
decls()142   const DeclsTy &decls() const {
143     return *reinterpret_cast<const DeclsTy*>(this);
144   }
145 };
146 
147 /// A set of unresolved declarations.
148 template <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