include/llvm/Support/FileCollector.h

   1 //===-- FileCollector.h -----------------------------------------*- 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 #ifndef LLVM_SUPPORT_FILE_COLLECTOR_H
  10 #define LLVM_SUPPORT_FILE_COLLECTOR_H
  11
  12 #include "llvm/ADT/SmallVector.h"
  13 #include "llvm/ADT/StringMap.h"
  14 #include "llvm/ADT/StringSet.h"
  15 #include "llvm/ADT/Twine.h"
  16 #include "llvm/Support/VirtualFileSystem.h"
  17
  18 #include <mutex>
  19
  20 namespace llvm {
  21
  22 /// Collects files into a directory and generates a mapping that can be used by
  23 /// the VFS.
  24 class FileCollector {
  25 public:
  26   FileCollector(std::string Root, std::string OverlayRoot);
  27
  28   void addFile(const Twine &file);
  29
  30   /// Write the yaml mapping (for the VFS) to the given file.
  31   std::error_code writeMapping(StringRef mapping_file);
  32
  33   /// Copy the files into the root directory.
  34   ///
  35   /// When StopOnError is true (the default) we abort as soon as one file
  36   /// cannot be copied. This is relatively common, for example when a file was
  37   /// removed after it was added to the mapping.
  38   std::error_code copyFiles(bool StopOnError = true);
  39
  40   /// Create a VFS that collects all the paths that might be looked at by the
  41   /// file system accesses.
  42   static IntrusiveRefCntPtr<vfs::FileSystem>
  43   createCollectorVFS(IntrusiveRefCntPtr<vfs::FileSystem> BaseFS,
  44                      std::shared_ptr<FileCollector> Collector);
  45
  46 private:
  47   void addFileImpl(StringRef SrcPath);
  48
  49   bool markAsSeen(StringRef Path) { return Seen.insert(Path).second; }
  50
  51   bool getRealPath(StringRef SrcPath, SmallVectorImpl<char> &Result);
  52
  53   void addFileToMapping(StringRef VirtualPath, StringRef RealPath) {
  54     VFSWriter.addFileMapping(VirtualPath, RealPath);
  55   }
  56
  57 protected:
  58   /// Synchronizes adding files.
  59   std::mutex Mutex;
  60
  61   /// The root directory where files are copied.
  62   std::string Root;
  63
  64   /// The root directory where the VFS overlay lives.
  65   std::string OverlayRoot;
  66
  67   /// Tracks already seen files so they can be skipped.
  68   StringSet<> Seen;
  69
  70   /// The yaml mapping writer.
  71   vfs::YAMLVFSWriter VFSWriter;
  72
  73   /// Caches RealPath calls when resolving symlinks.
  74   StringMap<std::string> SymlinkMap;
  75 };
  76
  77 } // end namespace llvm
  78
  79 #endif // LLVM_SUPPORT_FILE_COLLECTOR_H