[lldb/Support] Treat empty FileSpec as an invalid file.

lldb/source/Host/common/FileSystem.cpp

@@ -87,6 +87,11 @@ Optional<FileSystem> &FileSystem::InstanceImpl() {
 
 vfs::directory_iterator FileSystem::DirBegin(const FileSpec &file_spec,
                                              std::error_code &ec) {
+  if (!file_spec) {
+    ec = std::error_code(static_cast<int>(errc::no_such_file_or_directory),
+                         std::system_category());
+    return {};
+  }
   return DirBegin(file_spec.GetPath(), ec);
 }
 
@@ -97,6 +102,9 @@ vfs::directory_iterator FileSystem::DirBegin(const Twine &dir,
 
 llvm::ErrorOr<vfs::Status>
 FileSystem::GetStatus(const FileSpec &file_spec) const {
+  if (!file_spec)
+    return std::error_code(static_cast<int>(errc::no_such_file_or_directory),
+                           std::system_category());
   return GetStatus(file_spec.GetPath());
 }
 
@@ -106,6 +114,8 @@ llvm::ErrorOr<vfs::Status> FileSystem::GetStatus(const Twine &path) const {
 
 sys::TimePoint<>
 FileSystem::GetModificationTime(const FileSpec &file_spec) const {
+  if (!file_spec)
+    return sys::TimePoint<>();
   return GetModificationTime(file_spec.GetPath());
 }
 
@@ -117,6 +127,8 @@ sys::TimePoint<> FileSystem::GetModificationTime(const Twine &path) const {
 }
 
 uint64_t FileSystem::GetByteSize(const FileSpec &file_spec) const {
+  if (!file_spec)
+    return 0;
   return GetByteSize(file_spec.GetPath());
 }
 
@@ -133,6 +145,8 @@ uint32_t FileSystem::GetPermissions(const FileSpec &file_spec) const {
 
 uint32_t FileSystem::GetPermissions(const FileSpec &file_spec,
                                     std::error_code &ec) const {
+  if (!file_spec)
+    return sys::fs::perms::perms_not_known;
   return GetPermissions(file_spec.GetPath(), ec);
 }
 
@@ -154,15 +168,15 @@ uint32_t FileSystem::GetPermissions(const Twine &path,
 bool FileSystem::Exists(const Twine &path) const { return m_fs->exists(path); }
 
 bool FileSystem::Exists(const FileSpec &file_spec) const {
-  return Exists(file_spec.GetPath());
+  return file_spec && Exists(file_spec.GetPath());
 }
 
 bool FileSystem::Readable(const Twine &path) const {
   return GetPermissions(path) & sys::fs::perms::all_read;
 }
 
 bool FileSystem::Readable(const FileSpec &file_spec) const {
-  return Readable(file_spec.GetPath());
+  return file_spec && Readable(file_spec.GetPath());
 }
 
 bool FileSystem::IsDirectory(const Twine &path) const {
@@ -173,7 +187,7 @@ bool FileSystem::IsDirectory(const Twine &path) const {
 }
 
 bool FileSystem::IsDirectory(const FileSpec &file_spec) const {
-  return IsDirectory(file_spec.GetPath());
+  return file_spec && IsDirectory(file_spec.GetPath());
 }
 
 bool FileSystem::IsLocal(const Twine &path) const {
@@ -183,7 +197,7 @@ bool FileSystem::IsLocal(const Twine &path) const {
 }
 
 bool FileSystem::IsLocal(const FileSpec &file_spec) const {
-  return IsLocal(file_spec.GetPath());
+  return file_spec && IsLocal(file_spec.GetPath());
 }
 
 void FileSystem::EnumerateDirectory(Twine path, bool find_directories,
@@ -261,6 +275,9 @@ void FileSystem::Resolve(SmallVectorImpl<char> &path) {
 }
 
 void FileSystem::Resolve(FileSpec &file_spec) {
+  if (!file_spec)
+    return;
+
   // Extract path from the FileSpec.
   SmallString<128> path;
   file_spec.GetPath(path);

lldb/unittests/Host/FileSystemTest.cpp

@@ -303,3 +303,29 @@ TEST(FileSystemTest, OpenErrno) {
   EXPECT_EQ(code.value(), ENOENT);
 }
 
+TEST(FileSystemTest, EmptyTest) {
+  FileSpec spec;
+  FileSystem fs;
+
+  {
+    std::error_code ec;
+    fs.DirBegin(spec, ec);
+    EXPECT_EQ(ec.category(), std::system_category());
+    EXPECT_EQ(ec.value(), ENOENT);
+  }
+
+  {
+    llvm::ErrorOr<vfs::Status> status = fs.GetStatus(spec);
+    ASSERT_FALSE(status);
+    EXPECT_EQ(status.getError().category(), std::system_category());
+    EXPECT_EQ(status.getError().value(), ENOENT);
+  }
+
+  EXPECT_EQ(sys::TimePoint<>(), fs.GetModificationTime(spec));
+  EXPECT_EQ(static_cast<uint64_t>(0), fs.GetByteSize(spec));
+  EXPECT_EQ(llvm::sys::fs::perms::perms_not_known, fs.GetPermissions(spec));
+  EXPECT_FALSE(fs.Exists(spec));
+  EXPECT_FALSE(fs.Readable(spec));
+  EXPECT_FALSE(fs.IsDirectory(spec));
+  EXPECT_FALSE(fs.IsLocal(spec));
+}