Formatting fixes and include file hygiene.

PiperOrigin-RevId: 240346890
Change-Id: I1a9617f10a62a848b6314a6196512e016ae02643

sandboxed_api/embed_file.h

@@ -15,7 +15,6 @@
 #ifndef SANDBOXED_API_EMBED_FILE_H_
 #define SANDBOXED_API_EMBED_FILE_H_
 
-#include <string>
 #include <vector>
 
 #include "sandboxed_api/file_toc.h"

sandboxed_api/examples/stringop/lib/stringop.cc

@@ -50,7 +50,7 @@ extern "C" int reverse_string(sapi::LenValStruct* input) {
 
   // Free old value.
   free(input->data);
-  // Replace pointer to our new std::string.
+  // Replace pointer to our new string.
   input->data = new_buf;
   return 1;
 }

sandboxed_api/sandbox.h

@@ -16,6 +16,7 @@
 #define SANDBOXED_API_SANDBOX_H_
 
 #include <memory>
+#include <string>
 #include <vector>
 
 #include "sandboxed_api/file_toc.h"
@@ -71,7 +72,8 @@ class Sandbox {
 
   // Makes a call to the sandboxee.
   template <typename... Args>
-  ::sapi::Status Call(const std::string& func, v::Callable* ret, Args&&... args) {
+  ::sapi::Status Call(const std::string& func, v::Callable* ret,
+                      Args&&... args) {
     static_assert(sizeof...(Args) <= FuncCall::kArgsMax,
                   "Too many arguments to sapi::Sandbox::Call()");
     return Call(func, ret, {std::forward<Args>(args)...});

sandboxed_api/sandbox2/comms.cc

@@ -500,7 +500,7 @@ socklen_t Comms::CreateSockaddrUn(sockaddr_un* sun) {
   bzero(sun->sun_path, sizeof(sun->sun_path));
   // Create an 'abstract socket address' by specifying a leading null byte. The
   // remainder of the path is used as a unique name, but no file is created on
-  // the filesystem. No need to NUL-terminate the std::string.
+  // the filesystem. No need to NUL-terminate the string.
   // See `man 7 unix` for further explanation.
   strncpy(&sun->sun_path[1], socket_name_.c_str(), sizeof(sun->sun_path) - 1);
 

sandboxed_api/sandbox2/docs/getting-started.md

@@ -23,9 +23,9 @@ This is the simplest and safest way to use sandboxing. For examples see
 #include "sandboxed_api/sandbox2/executor.h"
 
 std::string path = "path/to/binary";
-std::vector<string> args = {path};  // args[0] will become the sandboxed
+std::vector<std::string> args = {path};  // args[0] will become the sandboxed
-                                    // process' argv[0], typically the path
+                                         // process' argv[0], typically the
-                                    // to the binary.
+                                         // path to the binary.
 auto executor = absl::make_unique<sandbox2::Executor>(path, args);
 ```
 

sandboxed_api/sandbox2/executor.h

@@ -105,9 +105,11 @@ class Executor final {
                  /*fork_client=*/nullptr) {}
 
   // Delegate constructor that gets called by the public ones.
-  Executor(int exec_fd, const std::string& path, const std::vector<std::string>& argv,
+  Executor(int exec_fd, const std::string& path,
-           const std::vector<std::string>& envp, bool enable_sandboxing_pre_execve,
+           const std::vector<std::string>& argv,
-           pid_t libunwind_sbox_for_pid, ForkClient* fork_client);
+           const std::vector<std::string>& envp,
+           bool enable_sandboxing_pre_execve, pid_t libunwind_sbox_for_pid,
+           ForkClient* fork_client);
 
   // Creates a copy of the environment
   static std::vector<std::string> CopyEnviron();

sandboxed_api/sandbox2/forkserver.h

@@ -19,6 +19,7 @@
 #define SANDBOXED_API_SANDBOX2_FORKSERVER_H_
 
 #include <sys/types.h>
+
 #include <string>
 #include <vector>
 

sandboxed_api/sandbox2/monitor.cc

@@ -93,7 +93,8 @@ Monitor::Monitor(Executor* executor, Policy* policy, Notify* notify)
       setup_counter_(new absl::BlockingCounter(1)),
       done_(false),
       wait_for_execve_(executor->enable_sandboxing_pre_execve_) {
-  std::string path = absl::GetFlag(FLAGS_sandbox2_danger_danger_permit_all_and_log);
+  std::string path =
+      absl::GetFlag(FLAGS_sandbox2_danger_danger_permit_all_and_log);
   if (!path.empty()) {
     log_file_ = std::fopen(path.c_str(), "a+");
     PCHECK(log_file_ != nullptr) << "Failed to open log file '" << path << "'";

sandboxed_api/sandbox2/mounts.cc

@@ -192,7 +192,7 @@ std::string GetPlatform(absl::string_view interpreter) {
 
   auto split = file::SplitPath(fixed_path);
   absl::string_view cur = split.first;
-  std::string final_part = std::string(split.second);
+  auto final_part = std::string(split.second);
 
   while (cur != "/") {
     auto split = file::SplitPath(cur);

sandboxed_api/sandbox2/mounts_test.cc

@@ -29,7 +29,6 @@
 using sapi::IsOk;
 using sapi::StatusIs;
 using ::testing::Eq;
-using ::testing::StrEq;
 
 namespace sandbox2 {
 namespace {

sandboxed_api/sandbox2/namespace.cc

@@ -29,7 +29,6 @@
 
 #include <cstdio>
 #include <cstring>
-#include <string>
 #include <utility>
 
 #include "absl/strings/str_cat.h"

sandboxed_api/sandbox2/namespace.h

@@ -22,6 +22,7 @@
 
 #include <cstdint>
 #include <memory>
+#include <string>
 
 #include "absl/base/macros.h"
 #include "sandboxed_api/sandbox2/mounts.h"
@@ -40,7 +41,8 @@ class Namespace final {
   Namespace(const Namespace&) = delete;
   Namespace& operator=(const Namespace&) = delete;
 
-  Namespace(bool allow_unrestricted_networking, Mounts mounts, std::string hostname);
+  Namespace(bool allow_unrestricted_networking, Mounts mounts,
+            std::string hostname);
 
   void DisableUserNamespace();
 

sandboxed_api/sandbox2/policy_test.cc

@@ -186,7 +186,8 @@ TEST(MinimalTest, MinimalBinaryWorks) {
 // Test that we can sandbox a minimal non-static binary returning 0.
 TEST(MinimalTest, MinimalSharedBinaryWorks) {
   SKIP_SANITIZERS_AND_COVERAGE;
-  const std::string path = GetTestSourcePath("sandbox2/testcases/minimal_dynamic");
+  const std::string path =
+      GetTestSourcePath("sandbox2/testcases/minimal_dynamic");
   std::vector<std::string> args = {path};
   auto executor = absl::make_unique<Executor>(path, args);
 
@@ -212,7 +213,8 @@ TEST(MinimalTest, MinimalSharedBinaryWorks) {
 // Test that the AllowSystemMalloc helper works as expected.
 TEST(MallocTest, SystemMallocWorks) {
   SKIP_SANITIZERS_AND_COVERAGE;
-  const std::string path = GetTestSourcePath("sandbox2/testcases/malloc_system");
+  const std::string path =
+      GetTestSourcePath("sandbox2/testcases/malloc_system");
   std::vector<std::string> args = {path};
   auto executor = absl::make_unique<Executor>(path, args);
 

sandboxed_api/sandbox2/policybuilder.cc

@@ -624,7 +624,8 @@ PolicyBuilder& PolicyBuilder::DangerDefaultAllowAll() {
   return ValidatePath(path);
 }
 
-::sapi::StatusOr<std::string> PolicyBuilder::ValidatePath(absl::string_view path) {
+::sapi::StatusOr<std::string> PolicyBuilder::ValidatePath(
+    absl::string_view path) {
   std::string fixed_path = file::CleanPath(path);
   if (fixed_path != path) {
     return ::sapi::InvalidArgumentError(absl::StrCat(

sandboxed_api/sandbox2/policybuilder.h

@@ -487,7 +487,8 @@ class PolicyBuilder final {
 
   std::vector<sock_filter> ResolveBpfFunc(BpfFunc f);
 
-  static ::sapi::StatusOr<std::string> ValidateAbsolutePath(absl::string_view path);
+  static ::sapi::StatusOr<std::string> ValidateAbsolutePath(
+      absl::string_view path);
   static ::sapi::StatusOr<std::string> ValidatePath(absl::string_view path);
 
   void StoreDescription(PolicyBuilderDescription* pb_description);

sandboxed_api/sandbox2/policybuilder_test.cc

@@ -17,6 +17,7 @@
 #include <syscall.h>
 #include <unistd.h>
 
+#include <string>
 #include <utility>
 
 #include <glog/logging.h>
@@ -56,7 +57,8 @@ class PolicyBuilderPeer {
 
   int policy_size() const { return builder_->output_->user_policy_.size(); }
 
-  static ::sapi::StatusOr<std::string> ValidateAbsolutePath(absl::string_view path) {
+  static ::sapi::StatusOr<std::string> ValidateAbsolutePath(
+      absl::string_view path) {
     return PolicyBuilder::ValidateAbsolutePath(path);
   }
 
@@ -154,7 +156,8 @@ TEST_F(PolicyBuilderTest, TestValidateAbsolutePath) {
   }
 }
 
-std::string PolicyBuilderTest::Run(std::vector<std::string> args, bool network) {
+std::string PolicyBuilderTest::Run(std::vector<std::string> args,
+                                   bool network) {
   PolicyBuilder builder;
   // Don't restrict the syscalls at all.
   builder.DangerDefaultAllowAll();

sandboxed_api/sandbox2/result.h

@@ -107,7 +107,9 @@ class Result {
   // The stacktrace must be sometimes fetched before SetExitStatusCode is
   // called, because after WIFEXITED() or WIFSIGNALED() the process is just a
   // zombie.
-  void SetStackTrace(const std::string& stack_trace) { stack_trace_ = stack_trace; }
+  void SetStackTrace(const std::string& stack_trace) {
+    stack_trace_ = stack_trace;
+  }
 
   void LoadRegs(pid_t pid) {
     auto regs = absl::make_unique<Regs>(pid);
@@ -150,13 +152,13 @@ class Result {
   // OK if the sandbox process exited normally with an exit code of 0.
   ::sapi::Status ToStatus() const;
 
-  // Returns a descriptive std::string for final result.
+  // Returns a descriptive string for final result.
   std::string ToString() const;
 
-  // Converts StatusEnum to a std::string.
+  // Converts StatusEnum to a string.
   static std::string StatusEnumToString(StatusEnum value);
 
-  // Converts ReasonCodeEnum to a std::string.
+  // Converts ReasonCodeEnum to a string.
   static std::string ReasonCodeEnumToString(ReasonCodeEnum value);
 
   rusage* GetRUsageMonitor() { return &rusage_monitor_; }

sandboxed_api/sandbox2/sandbox2_test.cc

@@ -59,8 +59,8 @@ TEST(SandboxCoreDumpTest, AbortWithoutCoreDumpReturnsSignaled) {
   Sandbox2 sandbox(std::move(executor), std::move(policy));
   auto result = sandbox.Run();
 
-  ASSERT_EQ(result.final_status(), Result::SIGNALED);
+  ASSERT_THAT(result.final_status(), Eq(Result::SIGNALED));
-  EXPECT_EQ(result.reason_code(), SIGABRT);
+  EXPECT_THAT(result.reason_code(), Eq(SIGABRT));
 }
 
 // Test that with TSYNC we are able to sandbox when multithreaded and with no

sandboxed_api/sandbox2/sanitizer.cc

@@ -31,6 +31,7 @@
 #include <cstring>
 #include <fstream>
 #include <sstream>
+#include <string>
 #include <utility>
 #include <vector>
 

sandboxed_api/sandbox2/sanitizer.h

@@ -19,7 +19,6 @@
 #define SANDBOXED_API_SANDBOX2_SANITIZER_H_
 
 #include <set>
-#include <string>
 
 #include "absl/base/macros.h"
 

sandboxed_api/sandbox2/sanitizer_test.cc

@@ -51,7 +51,7 @@ namespace sandbox2 {
 namespace {
 
 // Runs a new process and returns 0 if the process terminated with 0.
-static int RunTestcase(const std::string& path, const std::vector<std::string>& args) {
+int RunTestcase(const std::string& path, const std::vector<std::string>& args) {
   pid_t pid = fork();
   if (pid < 0) {
     PLOG(ERROR) << "fork()";
@@ -79,7 +79,7 @@ static int RunTestcase(const std::string& path, const std::vector<std::string>&
   }
 }
 
-static bool IsFdOpen(int fd) {
+bool IsFdOpen(int fd) {
   int ret = fcntl(fd, F_GETFD);
   if (ret == -1) {
     VLOG(1) << "FD: " << fd << " is closed";

sandboxed_api/sandbox2/stack-trace.cc

@@ -62,7 +62,8 @@ class StackTracePeer {
                                            const Mounts& mounts);
 
   static bool LaunchLibunwindSandbox(const Regs* regs, const Mounts& mounts,
-                                     UnwindResult* result, const std::string& delim);
+                                     UnwindResult* result,
+                                     const std::string& delim);
 };
 
 std::unique_ptr<Policy> StackTracePeer::GetPolicy(pid_t target_pid,

sandboxed_api/sandbox2/stack-trace_test.cc

@@ -153,7 +153,8 @@ TEST(StackTraceTest, ForkEnterNsLibunwindDoesNotLeakFDs) {
   SKIP_SANITIZERS_AND_COVERAGE;
   // Get list of open FDs in the global forkserver.
   pid_t forkserver_pid = GetGlobalForkServerPid();
-  std::string forkserver_fd_path = absl::StrCat("/proc/", forkserver_pid, "/fd");
+  std::string forkserver_fd_path =
+      absl::StrCat("/proc/", forkserver_pid, "/fd");
   size_t filecount_before = FileCountInDirectory(forkserver_fd_path);
 
   TemporaryFlagOverride<bool> temp_override(

sandboxed_api/sandbox2/testcases/ipc.cc

@@ -15,8 +15,8 @@
 // A binary that uses comms and client, to receive FDs by name, communicate
 // with them, sandboxed or not.
 
-#include <stdio.h>
+#include <cstdio>
-#include <stdlib.h>
+#include <cstdlib>
 #include <string>
 
 #include "absl/strings/numbers.h"

sandboxed_api/sandbox2/util.cc

@@ -296,7 +296,7 @@ std::string GetSignalName(int signo) {
   auto pos = path.find('\0');
   if (pos == std::string::npos) {
     return ::sapi::FailedPreconditionError(absl::StrCat(
-        "No NUL-byte inside the C std::string '", absl::CHexEscape(path), "'"));
+        "No NUL-byte inside the C string '", absl::CHexEscape(path), "'"));
   }
   path.resize(pos);
   return path;

sandboxed_api/sandbox2/util.h

@@ -31,7 +31,7 @@ namespace sandbox2 {
 namespace util {
 
 // Converts an array of char* (terminated by a nullptr, like argv, or environ
-// arrays), to an std::vector<string>.
+// arrays), to an std::vector<std::string>.
 void CharPtrArrToVecString(char* const* arr, std::vector<std::string>* vec);
 
 // Converts a vector of strings to a newly allocated array. The array is limited

sandboxed_api/sandbox2/util/fileops.cc

@@ -59,7 +59,8 @@ bool GetCWD(std::string* result) {
 
 // Makes a path absolute with respect to base. Returns true on success. Result
 // may be an alias of base or filename.
-bool MakeAbsolute(const std::string& filename, const std::string& base, std::string* result) {
+bool MakeAbsolute(const std::string& filename, const std::string& base,
+                  std::string* result) {
   if (filename.empty()) {
     return false;
   }
@@ -95,10 +96,10 @@ std::string MakeAbsolute(const std::string& filename, const std::string& base) {
 }
 
 bool RemoveLastPathComponent(const std::string& file, std::string* output) {
-  // Point idx at the last non-slash in the std::string. This should mark the last
+  // Point idx at the last non-slash in the string. This should mark the last
   // character of the base name.
   auto idx = file.find_last_not_of('/');
-  // If no non-slash is found, we have all slashes or an empty std::string. Return
+  // If no non-slash is found, we have all slashes or an empty string. Return
   // the appropriate value and false to indicate there was no path component to
   // remove.
   if (idx == std::string::npos) {
@@ -114,7 +115,7 @@ bool RemoveLastPathComponent(const std::string& file, std::string* output) {
   // Point idx at the last slash before the base name.
   idx = file.find_last_of('/', idx);
   // If we don't find a slash, then we have something of the form "file/*", so
-  // just return the empty std::string.
+  // just return the empty string.
   if (idx == std::string::npos) {
     output->clear();
   } else {
@@ -189,7 +190,8 @@ bool Exists(const std::string& filename, bool fully_resolve) {
                         : lstat64(filename.c_str(), &st)) != -1;
 }
 
-bool ListDirectoryEntries(const std::string& directory, std::vector<std::string>* entries,
+bool ListDirectoryEntries(const std::string& directory,
+                          std::vector<std::string>* entries,
                           std::string* error) {
   errno = 0;
   std::unique_ptr<DIR, void (*)(DIR*)> dir{opendir(directory.c_str()),
@@ -266,7 +268,8 @@ bool DeleteRecursively(const std::string& filename) {
   return true;
 }
 
-bool CopyFile(const std::string& old_path, const std::string& new_path, int new_mode) {
+bool CopyFile(const std::string& old_path, const std::string& new_path,
+              int new_mode) {
   {
     std::ifstream input(old_path, std::ios_base::binary);
     std::ofstream output(new_path,

sandboxed_api/sandbox2/util/fileops.h

@@ -72,7 +72,8 @@ bool Exists(const std::string& filename, bool fully_resolve);
 // On error, false is returned and error is set to a description of the
 // error. The filenames in entries are just the basenames of the
 // files found.
-bool ListDirectoryEntries(const std::string& directory, std::vector<std::string>* entries,
+bool ListDirectoryEntries(const std::string& directory,
+                          std::vector<std::string>* entries,
                           std::string* error);
 
 // Deletes the specified file or directory, including any sub-directories.
@@ -81,7 +82,8 @@ bool DeleteRecursively(const std::string& filename);
 // Copies a file from one location to another. The file will be overwritten  if
 // it already exists. If it does not exist, its mode will be new_mode. Returns
 // true on success. On failure, a partial copy of the file may remain.
-bool CopyFile(const std::string& old_path, const std::string& new_path, int new_mode);
+bool CopyFile(const std::string& old_path, const std::string& new_path,
+              int new_mode);
 
 // Makes filename absolute with respect to base. Returns an empty string on
 // failure.

sandboxed_api/sandbox2/util/maps_parser.cc

@@ -18,16 +18,18 @@
 
 namespace sandbox2 {
 
-::sapi::StatusOr<std::vector<MapsEntry>> ParseProcMaps(const std::string& contents) {
+::sapi::StatusOr<std::vector<MapsEntry>> ParseProcMaps(
-  // Note: The format std::string
+    const std::string& contents) {
+  // Note: The format string
   //       https://github.com/torvalds/linux/blob/v4.14/fs/proc/task_mmu.c#L289
-  //       changed to a non-format std::string implementation
+  //       changed to a non-format string implementation
   //       (show_vma_header_prefix()).
   static constexpr char kFormatString[] =
       "%lx-%lx %c%c%c%c %lx %x:%x %lu %1023s";
   static constexpr size_t kFilepathLength = 1023;
 
-  std::vector<std::string> lines = absl::StrSplit(contents, '\n', absl::SkipEmpty());
+  std::vector<std::string> lines =
+      absl::StrSplit(contents, '\n', absl::SkipEmpty());
   std::vector<MapsEntry> entries;
   for (const auto& line : lines) {
     MapsEntry entry{};

sandboxed_api/sandbox2/util/maps_parser.h

@@ -16,6 +16,7 @@
 #define SANDBOXED_API_SANDBOX2_UTIL_MAPS_PARSER_H_
 
 #include <cstdint>
+#include <string>
 #include <vector>
 
 #include "sandboxed_api/util/status.h"
@@ -37,7 +38,8 @@ struct MapsEntry {
   std::string path;
 };
 
-::sapi::StatusOr<std::vector<MapsEntry>> ParseProcMaps(const std::string& contents);
+::sapi::StatusOr<std::vector<MapsEntry>> ParseProcMaps(
+    const std::string& contents);
 
 }  // namespace sandbox2
 

sandboxed_api/sandbox2/util/path.cc

@@ -67,7 +67,7 @@ std::pair<absl::string_view, absl::string_view> SplitPath(
 }
 
 std::string CleanPath(const absl::string_view unclean_path) {
-  std::string path = std::string(unclean_path);
+  auto path = std::string(unclean_path);
   const char* src = path.c_str();
   std::string::iterator dst = path.begin();
 

sandboxed_api/sandbox2/util/strerror_test.cc

@@ -45,7 +45,7 @@ TEST(StrErrorTest, InvalidErrorCode) {
 TEST(StrErrorTest, MultipleThreads) {
   // In this test, we will start up 2 threads and have each one call StrError
   // 1000 times, each time with a different errnum. We expect that
-  // StrError(errnum) will return a std::string equal to the one returned by
+  // StrError(errnum) will return a string equal to the one returned by
   // strerror(errnum), if the code is known. Since strerror is known to be
   // thread-hostile, collect all the expected strings up front.
   constexpr int kNumCodes = 1000;

sandboxed_api/sandbox2/util/temp_file.cc

@@ -43,7 +43,8 @@ sapi::StatusOr<std::pair<std::string, int>> CreateNamedTempFile(
   return std::pair<std::string, int>{std::move(name_template), fd};
 }
 
-sapi::StatusOr<std::string> CreateNamedTempFileAndClose(absl::string_view prefix) {
+sapi::StatusOr<std::string> CreateNamedTempFileAndClose(
+    absl::string_view prefix) {
   auto result_or = CreateNamedTempFile(prefix);
   if (result_or.ok()) {
     std::string path;

sandboxed_api/sandbox2/util/temp_file.h

@@ -15,6 +15,8 @@
 #ifndef SANDBOXED_API_SANDBOX2_UTIL_TEMP_FILE_H_
 #define SANDBOXED_API_SANDBOX2_UTIL_TEMP_FILE_H_
 
+#include <string>
+
 #include "sandboxed_api/util/statusor.h"
 
 namespace sandbox2 {
@@ -27,7 +29,8 @@ sapi::StatusOr<std::pair<std::string, int>> CreateNamedTempFile(
 // Creates a temporary file under a path starting with prefix. File is not
 // unlinked and its path is returned. FD of the created file is closed just
 // after creation.
-sapi::StatusOr<std::string> CreateNamedTempFileAndClose(absl::string_view prefix);
+sapi::StatusOr<std::string> CreateNamedTempFileAndClose(
+    absl::string_view prefix);
 
 // Creates a temporary directory under a path starting with prefix.
 // Returns the path of the created directory.

sandboxed_api/sandbox2/util_test.cc

@@ -16,6 +16,8 @@
 
 #include <unistd.h>
 
+#include <string>
+
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include "sandboxed_api/sandbox2/testing.h"

sandboxed_api/util/status_internal.h

@@ -44,8 +44,8 @@ struct status_type_traits {
 
   template <typename StatusU>
   static auto CheckMinimalApi(...) -> decltype(std::false_type());
-  using minimal_api_type = decltype(
+  using minimal_api_type = decltype(CheckMinimalApi<StatusT>(
-      CheckMinimalApi<StatusT>(static_cast<StatusT*>(0), static_cast<int*>(0),
+      static_cast<StatusT*>(0), static_cast<int*>(0),
       static_cast<std::string*>(0), static_cast<bool*>(0)));
 
  public:

sandboxed_api/util/statusor_test.cc

@@ -106,7 +106,9 @@ struct StringCtor {
 struct StringVectorCtor {
   using value_type = std::vector<std::string>;
 
-  std::vector<std::string> operator()() { return {kStringElement, kErrorMessage}; }
+  std::vector<std::string> operator()() {
+    return {kStringElement, kErrorMessage};
+  }
 };
 
 bool operator==(const Foo& lhs, const Foo& rhs) {

sandboxed_api/var_abstract.h

@@ -16,6 +16,7 @@
 #define SANDBOXED_API_VAR_ABSTRACT_H_
 
 #include <memory>
+#include <string>
 #include <type_traits>
 
 #include "absl/base/macros.h"
@@ -55,10 +56,10 @@ class Var {
   // Returns the type of the variable.
   virtual Type GetType() const = 0;
 
-  // Returns a std::string representation of the variable type.
+  // Returns a string representation of the variable type.
   virtual std::string GetTypeString() const = 0;
 
-  // Returns a std::string representation of the variable value.
+  // Returns a string representation of the variable value.
   virtual std::string ToString() const = 0;
 
   virtual ~Var();