1 //===--- XRefs.h -------------------------------------------------*- 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 // Features that traverse references between symbols.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_XREFS_H
14 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_XREFS_H
15 
16 #include "Protocol.h"
17 #include "SourceCode.h"
18 #include "index/Index.h"
19 #include "index/SymbolID.h"
20 #include "index/SymbolLocation.h"
21 #include "support/Path.h"
22 #include "clang/AST/ASTTypeTraits.h"
23 #include "clang/AST/Type.h"
24 #include "clang/Format/Format.h"
25 #include "clang/Index/IndexSymbol.h"
26 #include "llvm/ADT/Optional.h"
27 #include "llvm/Support/raw_ostream.h"
28 #include <vector>
29 
30 namespace clang {
31 namespace syntax {
32 class Token;
33 class TokenBuffer;
34 } // namespace syntax
35 namespace clangd {
36 class ParsedAST;
37 
38 // Describes where a symbol is declared and defined (as far as clangd knows).
39 // There are three cases:
40 //  - a declaration only, no definition is known (e.g. only header seen)
41 //  - a declaration and a distinct definition (e.g. function declared in header)
42 //  - a declaration and an equal definition (e.g. inline function, or class)
43 // For some types of symbol, e.g. macros, definition == declaration always.
44 struct LocatedSymbol {
45   // The (unqualified) name of the symbol.
46   std::string Name;
47   // The canonical or best declaration: where most users find its interface.
48   Location PreferredDeclaration;
49   // Where the symbol is defined, if known. May equal PreferredDeclaration.
50   llvm::Optional<Location> Definition;
51   // SymbolID of the located symbol if available.
52   SymbolID ID;
53 };
54 llvm::raw_ostream &operator<<(llvm::raw_ostream &, const LocatedSymbol &);
55 /// Get definition of symbol at a specified \p Pos.
56 /// Multiple locations may be returned, corresponding to distinct symbols.
57 std::vector<LocatedSymbol> locateSymbolAt(ParsedAST &AST, Position Pos,
58                                           const SymbolIndex *Index = nullptr);
59 
60 // Tries to provide a textual fallback for locating a symbol by looking up the
61 // word under the cursor as a symbol name in the index.
62 // The aim is to pick up references to symbols in contexts where
63 // AST-based resolution does not work, such as comments, strings, and PP
64 // disabled regions.
65 // (This is for internal use by locateSymbolAt, and is exposed for testing).
66 std::vector<LocatedSymbol>
67 locateSymbolTextually(const SpelledWord &Word, ParsedAST &AST,
68                       const SymbolIndex *Index, const std::string &MainFilePath,
69                       ASTNodeKind NodeKind);
70 
71 // Try to find a proximate occurrence of `Word` as an identifier, which can be
72 // used to resolve it.
73 // (This is for internal use by locateSymbolAt, and is exposed for testing).
74 const syntax::Token *findNearbyIdentifier(const SpelledWord &Word,
75                                           const syntax::TokenBuffer &TB);
76 
77 /// Get all document links
78 std::vector<DocumentLink> getDocumentLinks(ParsedAST &AST);
79 
80 /// Returns highlights for all usages of a symbol at \p Pos.
81 std::vector<DocumentHighlight> findDocumentHighlights(ParsedAST &AST,
82                                                       Position Pos);
83 
84 struct ReferencesResult {
85   // Bitmask describing whether the occurrence is a declaration, definition etc.
86   enum ReferenceAttributes : unsigned {
87     Declaration = 1 << 0,
88     Definition = 1 << 1,
89     // The occurrence is an override of the target base method.
90     Override = 1 << 2,
91   };
92   struct Reference {
93     Location Loc;
94     unsigned Attributes = 0;
95   };
96   std::vector<Reference> References;
97   bool HasMore = false;
98 };
99 llvm::raw_ostream &operator<<(llvm::raw_ostream &,
100                               const ReferencesResult::Reference &);
101 
102 /// Returns implementations at a specified \p Pos:
103 ///   - overrides for a virtual method;
104 ///   - subclasses for a base class;
105 std::vector<LocatedSymbol> findImplementations(ParsedAST &AST, Position Pos,
106                                                const SymbolIndex *Index);
107 
108 /// Returns references of the symbol at a specified \p Pos.
109 /// \p Limit limits the number of results returned (0 means no limit).
110 ReferencesResult findReferences(ParsedAST &AST, Position Pos, uint32_t Limit,
111                                 const SymbolIndex *Index = nullptr);
112 
113 /// Get info about symbols at \p Pos.
114 std::vector<SymbolDetails> getSymbolInfo(ParsedAST &AST, Position Pos);
115 
116 /// Find the record type references at \p Pos.
117 const CXXRecordDecl *findRecordTypeAt(ParsedAST &AST, Position Pos);
118 
119 /// Given a record type declaration, find its base (parent) types.
120 std::vector<const CXXRecordDecl *> typeParents(const CXXRecordDecl *CXXRD);
121 
122 /// Get type hierarchy information at \p Pos.
123 llvm::Optional<TypeHierarchyItem> getTypeHierarchy(
124     ParsedAST &AST, Position Pos, int Resolve, TypeHierarchyDirection Direction,
125     const SymbolIndex *Index = nullptr, PathRef TUPath = PathRef{});
126 
127 void resolveTypeHierarchy(TypeHierarchyItem &Item, int ResolveLevels,
128                           TypeHierarchyDirection Direction,
129                           const SymbolIndex *Index);
130 
131 /// Get call hierarchy information at \p Pos.
132 std::vector<CallHierarchyItem>
133 prepareCallHierarchy(ParsedAST &AST, Position Pos, PathRef TUPath);
134 
135 std::vector<CallHierarchyIncomingCall>
136 incomingCalls(const CallHierarchyItem &Item, const SymbolIndex *Index);
137 
138 /// Returns all decls that are referenced in the \p FD except local symbols.
139 llvm::DenseSet<const Decl *> getNonLocalDeclRefs(ParsedAST &AST,
140                                                  const FunctionDecl *FD);
141 } // namespace clangd
142 } // namespace clang
143 
144 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANGD_XREFS_H
145