[FileCollector] Add a VFS that records FS accesses using the FileCollector

This patch adds a VFS that can be overlaid on top of another VFS
to record file system accesses using the FileCollector.
This can help to gather files that are needed for reproducers.

Differential Revision: https://reviews.llvm.org/D65411

llvm-svn: 367278

1 files changed, 55 insertions, 0 deletions

diff --git a/llvm/unittests/Support/FileCollectorTest.cpp b/llvm/unittests/Support/FileCollectorTest.cpp
index 07e745ce8f2..5505e884aa1 100644
--- a/llvm/unittests/Support/FileCollectorTest.cpp
+++ b/llvm/unittests/Support/FileCollectorTest.cpp
@@ -179,6 +179,44 @@ TEST(FileCollectorTest, recordAndConstructDirectory) {
   ASSERT_TRUE(IsDirectory);
 }
 
+TEST(FileCollectorTest, recordVFSAccesses) {
+  ScopedDir file_root("dir_root", true);
+  ScopedDir subdir(file_root + "/subdir");
+  ScopedDir subdir2(file_root + "/subdir2");
+  ScopedFile a(subdir2 + "/a");
+  ScopedFile b(file_root + "/b");
+  ScopedDir subdir3(file_root + "/subdir3");
+  ScopedFile subdir3a(subdir3 + "/aa");
+  ScopedDir subdir3b(subdir3 + "/subdirb");
+  {
+    ScopedFile subdir3fileremoved(subdir3 + "/removed");
+  }
+
+  // Create file collector and add files.
+  ScopedDir root("copy_files_root", true);
+  std::string root_fs = root.Path.str();
+  auto Collector = std::make_shared<TestingFileCollector>(root_fs, root_fs);
+  auto VFS =
+      FileCollector::createCollectorVFS(vfs::getRealFileSystem(), Collector);
+  VFS->status(a.Path);
+  EXPECT_TRUE(Collector->hasSeen(a.Path));
+
+  VFS->openFileForRead(b.Path);
+  EXPECT_TRUE(Collector->hasSeen(b.Path));
+
+  VFS->status(subdir.Path);
+  EXPECT_TRUE(Collector->hasSeen(subdir.Path));
+
+  std::error_code EC;
+  auto It = VFS->dir_begin(subdir3.Path, EC);
+  EXPECT_FALSE(EC);
+  EXPECT_TRUE(Collector->hasSeen(subdir3.Path));
+  EXPECT_TRUE(Collector->hasSeen(subdir3a.Path));
+  EXPECT_TRUE(Collector->hasSeen(subdir3b.Path));
+  std::string RemovedFileName = (Twine(subdir3.Path) + "/removed").str();
+  EXPECT_FALSE(Collector->hasSeen(RemovedFileName));
+}
+
 #ifndef _WIN32
 TEST(FileCollectorTest, Symlinks) {
   // Root where the original files live.
@@ -239,4 +277,21 @@ TEST(FileCollectorTest, Symlinks) {
     EXPECT_THAT(mapping, testing::Contains(vfs::YAMLVFSEntry(vpath, rpath)));
   }
 }
+
+TEST(FileCollectorTest, recordVFSSymlinkAccesses) {
+  ScopedDir file_root("dir_root", true);
+  ScopedFile a(file_root + "/a");
+  ScopedLink symlink(file_root + "/a", file_root + "/b");
+
+  // Create file collector and add files.
+  ScopedDir root("copy_files_root", true);
+  std::string root_fs = root.Path.str();
+  auto Collector = std::make_shared<TestingFileCollector>(root_fs, root_fs);
+  auto VFS =
+      FileCollector::createCollectorVFS(vfs::getRealFileSystem(), Collector);
+  SmallString<256> Output;
+  VFS->getRealPath(symlink.Path, Output);
+  EXPECT_TRUE(Collector->hasSeen(a.Path));
+  EXPECT_TRUE(Collector->hasSeen(symlink.Path));
+}
 #endif