llvm/clang-tools-extra/clangd/index/FileIndex.h

//===--- FileIndex.h - Index for files. ---------------------------- C++-*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// FileIndex implements SymbolIndex for symbols from a set of files. Symbols are
// maintained at source-file granularity (e.g. with ASTs), and files can be
// updated dynamically.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_FILEINDEX_H
#define LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_FILEINDEX_H

#include "Headers.h"
#include "clang-include-cleaner/Record.h"
#include "index/Index.h"
#include "index/Merge.h"
#include "index/Ref.h"
#include "index/Relation.h"
#include "index/Serialization.h"
#include "index/Symbol.h"
#include "support/MemoryTree.h"
#include "support/Path.h"
#include "clang/Lex/Preprocessor.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include <memory>
#include <optional>
#include <vector>

namespace clang {
class ASTContext;
namespace clangd {
class ParsedAST;

/// Select between in-memory index implementations, which have tradeoffs.
enum class IndexType { … };

/// How to handle duplicated symbols across multiple files.
enum class DuplicateHandling { … };

/// A container of slabs associated with a key. It can be updated at key
/// granularity, replacing all slabs belonging to a key with a new set. Keys are
/// usually file paths/uris.
///
/// This implements snapshot semantics. Each update will create a new snapshot
/// for all slabs of the Key. Snapshots are managed with shared pointers that
/// are shared between this class and the users. For each key, this class only
/// stores a pointer pointing to the newest snapshot, and an outdated snapshot
/// is deleted by the last owner of the snapshot, either this class or the
/// symbol index.
///
/// The snapshot semantics keeps critical sections minimal since we only need
/// locking when we swap or obtain references to snapshots.
class FileSymbols { … };

/// This manages symbols from files and an in-memory index on all symbols.
/// FIXME: Expose an interface to remove files that are closed.
class FileIndex : public MergedIndex { … };

SlabTuple;

/// Retrieves symbols and refs of local top level decls in \p AST (i.e.
/// `AST.getLocalTopLevelDecls()`).
/// Exposed to assist in unit tests.
SlabTuple indexMainDecls(ParsedAST &AST);

/// Index declarations from \p AST and macros from \p PP that are declared in
/// included headers.
SlabTuple indexHeaderSymbols(llvm::StringRef Version, ASTContext &AST,
                             Preprocessor &PP,
                             const include_cleaner::PragmaIncludes &PI);

/// Takes slabs coming from a TU (multiple files) and shards them per
/// declaration location.
struct FileShardedIndex { … };

} // namespace clangd
} // namespace clang

#endif // LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_FILEINDEX_H