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

//===--- SymbolID.h ----------------------------------------------*- 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
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_SYMBOLID_H
#define LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_SYMBOLID_H

#include "llvm/ADT/Hashing.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/raw_ostream.h"
#include <array>
#include <cstddef>
#include <cstdint>
#include <string>

namespace clang {
namespace clangd {

// The class identifies a particular C++ symbol (class, function, method, etc).
//
// As USRs (Unified Symbol Resolution) could be large, especially for functions
// with long type arguments, SymbolID is using truncated SHA1(USR) values to
// guarantee the uniqueness of symbols while using a relatively small amount of
// memory (vs storing USRs directly).
//
// SymbolID can be used as key in the symbol indexes to lookup the symbol.
class SymbolID { … };

inline llvm::hash_code hash_value(const SymbolID &ID) { … }

// Write SymbolID into the given stream. SymbolID is encoded as ID.str().
llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const SymbolID &ID);

} // namespace clangd
} // namespace clang

namespace llvm {
// Support SymbolIDs as DenseMap keys.
template <> struct DenseMapInfo<clang::clangd::SymbolID> { … };
} // namespace llvm

#endif // LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_SYMBOLID_H