xref: /llvm-project/clang-tools-extra/clangd/index/Serialization.h (revision 61fe67a4017375fd675f75652e857e837f77fa51)
1 //===--- Serialization.h - Binary serialization of index data ----*- 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 provides serialization of indexed symbols and other data.
10 //
11 // It writes sections:
12 //  - metadata such as version info
13 //  - a string table (which is compressed)
14 //  - lists of encoded symbols
15 //
16 // The format has a simple versioning scheme: the format version number is
17 // written in the file and non-current versions are rejected when reading.
18 //
19 // Human-readable YAML serialization is also supported, and recommended for
20 // debugging and experiments only.
21 //
22 //===----------------------------------------------------------------------===//
23 
24 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_SERIALIZATION_H
25 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_SERIALIZATION_H
26 
27 #include "Headers.h"
28 #include "index/Index.h"
29 #include "index/Symbol.h"
30 #include "clang/Tooling/CompilationDatabase.h"
31 #include "llvm/Support/Error.h"
32 #include <optional>
33 
34 namespace clang {
35 namespace clangd {
36 
37 enum class IndexFileFormat {
38   RIFF, // Versioned binary format, suitable for production use.
39   YAML, // Human-readable format, suitable for experiments and debugging.
40 };
41 
42 // Holds the contents of an index file that was read.
43 struct IndexFileIn {
44   std::optional<SymbolSlab> Symbols;
45   std::optional<RefSlab> Refs;
46   std::optional<RelationSlab> Relations;
47   // Keys are URIs of the source files.
48   std::optional<IncludeGraph> Sources;
49   // This contains only the Directory and CommandLine.
50   std::optional<tooling::CompileCommand> Cmd;
51 };
52 // Parse an index file. The input must be a RIFF or YAML file.
53 llvm::Expected<IndexFileIn> readIndexFile(llvm::StringRef, SymbolOrigin);
54 
55 // Specifies the contents of an index file to be written.
56 struct IndexFileOut {
57   const SymbolSlab *Symbols = nullptr;
58   const RefSlab *Refs = nullptr;
59   const RelationSlab *Relations = nullptr;
60   // Keys are URIs of the source files.
61   const IncludeGraph *Sources = nullptr;
62   // TODO: Support serializing Dex posting lists.
63   IndexFileFormat Format = IndexFileFormat::RIFF;
64   const tooling::CompileCommand *Cmd = nullptr;
65 
66   IndexFileOut() = default;
67   IndexFileOut(const IndexFileIn &I)
68       : Symbols(I.Symbols ? &*I.Symbols : nullptr),
69         Refs(I.Refs ? &*I.Refs : nullptr),
70         Relations(I.Relations ? &*I.Relations : nullptr),
71         Sources(I.Sources ? &*I.Sources : nullptr),
72         Cmd(I.Cmd ? &*I.Cmd : nullptr) {}
73 };
74 // Serializes an index file.
75 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const IndexFileOut &O);
76 
77 // Convert a single symbol to YAML, a nice debug representation.
78 std::string toYAML(const Symbol &);
79 std::string toYAML(const std::pair<SymbolID, ArrayRef<Ref>> &);
80 std::string toYAML(const Relation &);
81 std::string toYAML(const Ref &);
82 
83 // Build an in-memory static index from an index file.
84 // The size should be relatively small, so data can be managed in memory.
85 std::unique_ptr<SymbolIndex> loadIndex(llvm::StringRef Filename,
86                                        SymbolOrigin Origin, bool UseDex,
87                                        bool SupportContainedRefs);
88 
89 } // namespace clangd
90 } // namespace clang
91 
92 #endif
93