1 //===- IdentifierResolver.h - Lexical Scope Name lookup ---------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 // This file defines the IdentifierResolver class, which is used for lexical
10 // scoped lookup, based on declaration names.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_CLANG_SEMA_IDENTIFIERRESOLVER_H
15 #define LLVM_CLANG_SEMA_IDENTIFIERRESOLVER_H
17 #include "clang/Basic/LLVM.h"
18 #include "llvm/ADT/SmallVector.h"
27 class DeclarationName;
35 /// IdentifierResolver - Keeps track of shadowed decls on enclosing
36 /// scopes. It manages the shadowing chains of declaration names and
37 /// implements efficient decl lookup based on a declaration name.
38 class IdentifierResolver {
39 /// IdDeclInfo - Keeps track of information about decls associated
40 /// to a particular declaration name. IdDeclInfos are lazily
41 /// constructed and assigned to a declaration name the first time a
42 /// decl with that declaration name is shadowed in some scope.
45 using DeclsTy = SmallVector<NamedDecl *, 2>;
47 DeclsTy::iterator decls_begin() { return Decls.begin(); }
48 DeclsTy::iterator decls_end() { return Decls.end(); }
50 void AddDecl(NamedDecl *D) { Decls.push_back(D); }
52 /// RemoveDecl - Remove the decl from the scope chain.
53 /// The decl must already be part of the decl chain.
54 void RemoveDecl(NamedDecl *D);
56 /// Insert the given declaration at the given position in the list.
57 void InsertDecl(DeclsTy::iterator Pos, NamedDecl *D) {
66 /// iterator - Iterate over the decls of a specified declaration name.
67 /// It will walk or not the parent declaration contexts depending on how
68 /// it was instantiated.
71 friend class IdentifierResolver;
73 using value_type = NamedDecl *;
74 using reference = NamedDecl *;
75 using pointer = NamedDecl *;
76 using iterator_category = std::input_iterator_tag;
77 using difference_type = std::ptrdiff_t;
79 /// Ptr - There are 2 forms that 'Ptr' represents:
80 /// 1) A single NamedDecl. (Ptr & 0x1 == 0)
81 /// 2) A IdDeclInfo::DeclsTy::iterator that traverses only the decls of the
82 /// same declaration context. (Ptr & 0x1 == 0x1)
84 using BaseIter = IdDeclInfo::DeclsTy::iterator;
86 /// A single NamedDecl. (Ptr & 0x1 == 0)
87 iterator(NamedDecl *D) {
88 Ptr = reinterpret_cast<uintptr_t>(D);
89 assert((Ptr & 0x1) == 0 && "Invalid Ptr!");
92 /// A IdDeclInfo::DeclsTy::iterator that walks or not the parent declaration
93 /// contexts depending on 'LookInParentCtx'.
94 iterator(BaseIter I) {
95 Ptr = reinterpret_cast<uintptr_t>(I) | 0x1;
98 bool isIterator() const { return (Ptr & 0x1); }
100 BaseIter getIterator() const {
101 assert(isIterator() && "Ptr not an iterator!");
102 return reinterpret_cast<BaseIter>(Ptr & ~0x1);
105 void incrementSlowCase();
108 iterator() = default;
110 NamedDecl *operator*() const {
112 return *getIterator();
114 return reinterpret_cast<NamedDecl*>(Ptr);
117 bool operator==(const iterator &RHS) const {
118 return Ptr == RHS.Ptr;
120 bool operator!=(const iterator &RHS) const {
121 return Ptr != RHS.Ptr;
125 iterator& operator++() {
126 if (!isIterator()) // common case.
134 explicit IdentifierResolver(Preprocessor &PP);
135 ~IdentifierResolver();
137 /// begin - Returns an iterator for decls with the name 'Name'.
138 iterator begin(DeclarationName Name);
140 /// end - Returns an iterator that has 'finished'.
145 /// isDeclInScope - If 'Ctx' is a function/method, isDeclInScope returns true
146 /// if 'D' is in Scope 'S', otherwise 'S' is ignored and isDeclInScope returns
147 /// true if 'D' belongs to the given declaration context.
149 /// \param AllowInlineNamespace If \c true, we are checking whether a prior
150 /// declaration is in scope in a declaration that requires a prior
151 /// declaration (because it is either explicitly qualified or is a
152 /// template instantiation or specialization). In this case, a
153 /// declaration is in scope if it's in the inline namespace set of the
155 bool isDeclInScope(Decl *D, DeclContext *Ctx, Scope *S = nullptr,
156 bool AllowInlineNamespace = false) const;
158 /// AddDecl - Link the decl to its shadowed decl chain.
159 void AddDecl(NamedDecl *D);
161 /// RemoveDecl - Unlink the decl from its shadowed decl chain.
162 /// The decl must already be part of the decl chain.
163 void RemoveDecl(NamedDecl *D);
165 /// Insert the given declaration after the given iterator
167 void InsertDeclAfter(iterator Pos, NamedDecl *D);
169 /// Try to add the given declaration to the top level scope, if it
170 /// (or a redeclaration of it) hasn't already been added.
172 /// \param D The externally-produced declaration to add.
174 /// \param Name The name of the externally-produced declaration.
176 /// \returns true if the declaration was added, false otherwise.
177 bool tryAddTopLevelDecl(NamedDecl *D, DeclarationName Name);
180 const LangOptions &LangOpt;
184 IdDeclInfoMap *IdDeclInfos;
186 void updatingIdentifier(IdentifierInfo &II);
187 void readingIdentifier(IdentifierInfo &II);
189 /// FETokenInfo contains a Decl pointer if lower bit == 0.
190 static inline bool isDeclPtr(void *Ptr) {
191 return (reinterpret_cast<uintptr_t>(Ptr) & 0x1) == 0;
194 /// FETokenInfo contains a IdDeclInfo pointer if lower bit == 1.
195 static inline IdDeclInfo *toIdDeclInfo(void *Ptr) {
196 assert((reinterpret_cast<uintptr_t>(Ptr) & 0x1) == 1
197 && "Ptr not a IdDeclInfo* !");
198 return reinterpret_cast<IdDeclInfo*>(
199 reinterpret_cast<uintptr_t>(Ptr) & ~0x1);
205 #endif // LLVM_CLANG_SEMA_IDENTIFIERRESOLVER_H