clang-tools-extra/clangd/unittests/TestFS.h

   1 //===-- TestFS.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 // Allows setting up fake filesystem environments for tests.
  10 //
  11 //===----------------------------------------------------------------------===//
  12 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_UNITTESTS_TESTFS_H
  13 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_UNITTESTS_TESTFS_H
  14 #include "GlobalCompilationDatabase.h"
  15 #include "support/Path.h"
  16 #include "support/ThreadsafeFS.h"
  17 #include "llvm/ADT/IntrusiveRefCntPtr.h"
  18 #include "llvm/Support/Path.h"
  19 #include "llvm/Support/VirtualFileSystem.h"
  20 #include <optional>
  21
  22 namespace clang {
  23 namespace clangd {
  24
  25 // Builds a VFS that provides access to the provided files, plus temporary
  26 // directories.
  27 llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>
  28 buildTestFS(llvm::StringMap<std::string> const &Files,
  29             llvm::StringMap<time_t> const &Timestamps = {});
  30
  31 // A VFS provider that returns TestFSes containing a provided set of files.
  32 class MockFS : public ThreadsafeFS {
  33 public:
  34   IntrusiveRefCntPtr<llvm::vfs::FileSystem> viewImpl() const override {
  35     auto MemFS = buildTestFS(Files, Timestamps);
  36     if (!OverlayRealFileSystemForModules)
  37       return MemFS;
  38     llvm::IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> OverlayFileSystem =
  39         new llvm::vfs::OverlayFileSystem(llvm::vfs::getRealFileSystem());
  40     OverlayFileSystem->pushOverlay(MemFS);
  41     return OverlayFileSystem;
  42   }
  43
  44   // If relative paths are used, they are resolved with testPath().
  45   llvm::StringMap<std::string> Files;
  46   llvm::StringMap<time_t> Timestamps;
  47   // If true, real file system will be used as fallback for the in-memory one.
  48   // This is useful for testing module support.
  49   bool OverlayRealFileSystemForModules = false;
  50 };
  51
  52 // A Compilation database that returns a fixed set of compile flags.
  53 class MockCompilationDatabase : public GlobalCompilationDatabase {
  54 public:
  55   /// If \p Directory is not empty, use that as the Directory field of the
  56   /// CompileCommand, and as project SourceRoot.
  57   ///
  58   /// If \p RelPathPrefix is not empty, use that as a prefix in front of the
  59   /// source file name, instead of using an absolute path.
  60   MockCompilationDatabase(StringRef Directory = StringRef(),
  61                           StringRef RelPathPrefix = StringRef());
  62
  63   std::optional<tooling::CompileCommand>
  64   getCompileCommand(PathRef File) const override;
  65
  66   std::optional<ProjectInfo> getProjectInfo(PathRef File) const override;
  67
  68   std::vector<std::string> ExtraClangFlags;
  69
  70 private:
  71   StringRef Directory;
  72   StringRef RelPathPrefix;
  73 };
  74
  75 // Returns an absolute (fake) test directory for this OS.
  76 const char *testRoot();
  77
  78 // Returns a suitable absolute path for this OS.
  79 std::string testPath(PathRef File,
  80                      llvm::sys::path::Style = llvm::sys::path::Style::native);
  81
  82 // unittest: is a scheme that refers to files relative to testRoot()
  83 // This anchor is used to force the linker to link in the generated object file
  84 // and thus register unittest: URI scheme plugin.
  85 extern volatile int UnittestSchemeAnchorSource;
  86
  87 } // namespace clangd
  88 } // namespace clang
  89 #endif