llvm/llvm/include/llvm/Support/FileCollector.h

//===-- FileCollector.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_SUPPORT_FILECOLLECTOR_H
#define LLVM_SUPPORT_FILECOLLECTOR_H

#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/Support/VirtualFileSystem.h"
#include <mutex>
#include <string>

namespace llvm {
class FileCollectorFileSystem;
class Twine;

class FileCollectorBase { … };

/// Captures file system interaction and generates data to be later replayed
/// with the RedirectingFileSystem.
///
/// For any file that gets accessed we eventually create:
/// - a copy of the file inside Root
/// - a record in RedirectingFileSystem mapping that maps:
///   current real path -> path to the copy in Root
///
/// That intent is that later when the mapping is used by RedirectingFileSystem
/// it simulates the state of FS that we collected.
///
/// We generate file copies and mapping lazily - see writeMapping and copyFiles.
/// We don't try to capture the state of the file at the exact time when it's
/// accessed. Files might get changed, deleted ... we record only the "final"
/// state.
///
/// In order to preserve the relative topology of files we use their real paths
/// as relative paths inside of the Root.
class FileCollector : public FileCollectorBase { … };

} // end namespace llvm

#endif // LLVM_SUPPORT_FILECOLLECTOR_H