clang-tools-extra/clangd/index/Serialization.h

   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
  33 namespace clang {
  34 namespace clangd {
  35
  36 enum class IndexFileFormat {
  37   RIFF, // Versioned binary format, suitable for production use.
  38   YAML, // Human-readable format, suitable for experiments and debugging.
  39 };
  40
  41 // Holds the contents of an index file that was read.
  42 struct IndexFileIn {
  43   llvm::Optional<SymbolSlab> Symbols;
  44   llvm::Optional<RefSlab> Refs;
  45   llvm::Optional<RelationSlab> Relations;
  46   // Keys are URIs of the source files.
  47   llvm::Optional<IncludeGraph> Sources;
  48   // This contains only the Directory and CommandLine.
  49   llvm::Optional<tooling::CompileCommand> Cmd;
  50 };
  51 // Parse an index file. The input must be a RIFF or YAML file.
  52 llvm::Expected<IndexFileIn> readIndexFile(llvm::StringRef, SymbolOrigin);
  53
  54 // Specifies the contents of an index file to be written.
  55 struct IndexFileOut {
  56   const SymbolSlab *Symbols = nullptr;
  57   const RefSlab *Refs = nullptr;
  58   const RelationSlab *Relations = nullptr;
  59   // Keys are URIs of the source files.
  60   const IncludeGraph *Sources = nullptr;
  61   // TODO: Support serializing Dex posting lists.
  62   IndexFileFormat Format = IndexFileFormat::RIFF;
  63   const tooling::CompileCommand *Cmd = nullptr;
  64
  65   IndexFileOut() = default;
  66   IndexFileOut(const IndexFileIn &I)
  67       : Symbols(I.Symbols ? I.Symbols.getPointer() : nullptr),
  68         Refs(I.Refs ? I.Refs.getPointer() : nullptr),
  69         Relations(I.Relations ? I.Relations.getPointer() : nullptr),
  70         Sources(I.Sources ? I.Sources.getPointer() : nullptr),
  71         Cmd(I.Cmd ? I.Cmd.getPointer() : nullptr) {}
  72 };
  73 // Serializes an index file.
  74 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const IndexFileOut &O);
  75
  76 // Convert a single symbol to YAML, a nice debug representation.
  77 std::string toYAML(const Symbol &);
  78 std::string toYAML(const std::pair<SymbolID, ArrayRef<Ref>> &);
  79 std::string toYAML(const Relation &);
  80 std::string toYAML(const Ref &);
  81
  82 // Build an in-memory static index from an index file.
  83 // The size should be relatively small, so data can be managed in memory.
  84 std::unique_ptr<SymbolIndex> loadIndex(llvm::StringRef Filename,
  85                                        SymbolOrigin Origin, bool UseDex = true);
  86
  87 } // namespace clangd
  88 } // namespace clang
  89
  90 #endif