NewGC: Merge bleeding edge up to 9009.

samples/shell.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
 //       with the distribution.
 //     * Neither the name of Google Inc. nor the names of its
 //       contributors may be used to endorse or promote products derived
 //       from this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <v8.h>
-#include <v8-testing.h>
 #include <assert.h>
-#ifdef COMPRESS_STARTUP_DATA_BZ2
-#include <bzlib.h>
-#endif
 #include <fcntl.h>
 #include <string.h>
 #include <stdio.h>
 #include <stdlib.h>
 
-// When building with V8 in a shared library we cannot use functions which
-// is not explicitly a part of the public V8 API. This extensive use of
-// #ifndef USING_V8_SHARED/#endif is a hack until we can resolve whether to
-// still use the shell sample for testing or change to use the developer
-// shell d8 TODO(1272).
-#if !(defined(USING_V8_SHARED) || defined(V8_SHARED))
-#include "../src/v8.h"
-#endif  // USING_V8_SHARED
-
-#if !defined(_WIN32) && !defined(_WIN64)
-#include <unistd.h>  // NOLINT
+#ifdef COMPRESS_STARTUP_DATA_BZ2
+#error Using compressed startup data is not supported for this sample
 #endif
 
-static void ExitShell(int exit_code) {
-  // Use _exit instead of exit to avoid races between isolate
-  // threads and static destructors.
-  fflush(stdout);
-  fflush(stderr);
-  _exit(exit_code);
-}
+/**
+ * This sample program shows how to implement a simple javascript shell
+ * based on V8.  This includes initializing V8 with command line options,
+ * creating global functions, compiling and executing strings.
+ *
+ * For a more sophisticated shell, consider using the debug shell D8.
+ */
+
 
 v8::Persistent<v8::Context> CreateShellContext();
 void RunShell(v8::Handle<v8::Context> context);
+int RunMain(int argc, char* argv[]);
 bool ExecuteString(v8::Handle<v8::String> source,
                    v8::Handle<v8::Value> name,
                    bool print_result,
                    bool report_exceptions);
 v8::Handle<v8::Value> Print(const v8::Arguments& args);
 v8::Handle<v8::Value> Read(const v8::Arguments& args);
 v8::Handle<v8::Value> Load(const v8::Arguments& args);
 v8::Handle<v8::Value> Quit(const v8::Arguments& args);
 v8::Handle<v8::Value> Version(const v8::Arguments& args);
-v8::Handle<v8::Value> Int8Array(const v8::Arguments& args);
-v8::Handle<v8::Value> Uint8Array(const v8::Arguments& args);
-v8::Handle<v8::Value> Int16Array(const v8::Arguments& args);
-v8::Handle<v8::Value> Uint16Array(const v8::Arguments& args);
-v8::Handle<v8::Value> Int32Array(const v8::Arguments& args);
-v8::Handle<v8::Value> Uint32Array(const v8::Arguments& args);
-v8::Handle<v8::Value> Float32Array(const v8::Arguments& args);
-v8::Handle<v8::Value> Float64Array(const v8::Arguments& args);
-v8::Handle<v8::Value> PixelArray(const v8::Arguments& args);
 v8::Handle<v8::String> ReadFile(const char* name);
 void ReportException(v8::TryCatch* handler);
 
 
-static bool last_run = true;
-
-class SourceGroup {
- public:
-  SourceGroup() :
-#if !(defined(USING_V8_SHARED) || defined(V8_SHARED))
-                  next_semaphore_(v8::internal::OS::CreateSemaphore(0)),
-                  done_semaphore_(v8::internal::OS::CreateSemaphore(0)),
-                  thread_(NULL),
-#endif  // USING_V8_SHARED
-                  argv_(NULL),
-                  begin_offset_(0),
-                  end_offset_(0) { }
-
-#if !(defined(USING_V8_SHARED) || defined(V8_SHARED))
-  ~SourceGroup() {
-    delete next_semaphore_;
-    delete done_semaphore_;
-  }
-#endif  // USING_V8_SHARED
-
-  void Begin(char** argv, int offset) {
-    argv_ = const_cast<const char**>(argv);
-    begin_offset_ = offset;
-  }
-
-  void End(int offset) { end_offset_ = offset; }
-
-  void Execute() {
-    for (int i = begin_offset_; i < end_offset_; ++i) {
-      const char* arg = argv_[i];
-      if (strcmp(arg, "-e") == 0 && i + 1 < end_offset_) {
-        // Execute argument given to -e option directly.
-        v8::HandleScope handle_scope;
-        v8::Handle<v8::String> file_name = v8::String::New("unnamed");
-        v8::Handle<v8::String> source = v8::String::New(argv_[i + 1]);
-        if (!ExecuteString(source, file_name, false, true)) {
-          ExitShell(1);
-          return;
-        }
-        ++i;
-      } else if (arg[0] == '-') {
-        // Ignore other options. They have been parsed already.
-      } else {
-        // Use all other arguments as names of files to load and run.
-        v8::HandleScope handle_scope;
-        v8::Handle<v8::String> file_name = v8::String::New(arg);
-        v8::Handle<v8::String> source = ReadFile(arg);
-        if (source.IsEmpty()) {
-          printf("Error reading '%s'\n", arg);
-          continue;
-        }
-        if (!ExecuteString(source, file_name, false, true)) {
-          ExitShell(1);
-          return;
-        }
-      }
-    }
-  }
-
-#if !(defined(USING_V8_SHARED) || defined(V8_SHARED))
-  void StartExecuteInThread() {
-    if (thread_ == NULL) {
-      thread_ = new IsolateThread(this);
-      thread_->Start();
-    }
-    next_semaphore_->Signal();
-  }
-
-  void WaitForThread() {
-    if (thread_ == NULL) return;
-    if (last_run) {
-      thread_->Join();
-      thread_ = NULL;
-    } else {
-      done_semaphore_->Wait();
-    }
-  }
-#endif  // USING_V8_SHARED
-
- private:
-#if !(defined(USING_V8_SHARED) || defined(V8_SHARED))
-  static v8::internal::Thread::Options GetThreadOptions() {
-    v8::internal::Thread::Options options;
-    options.name = "IsolateThread";
-    // On some systems (OSX 10.6) the stack size default is 0.5Mb or less
-    // which is not enough to parse the big literal expressions used in tests.
-    // The stack size should be at least StackGuard::kLimitSize + some
-    // OS-specific padding for thread startup code.
-    options.stack_size = 2 << 20;  // 2 Mb seems to be enough
-    return options;
-  }
-
-  class IsolateThread : public v8::internal::Thread {
-   public:
-    explicit IsolateThread(SourceGroup* group)
-        : v8::internal::Thread(GetThreadOptions()), group_(group) {}
-
-    virtual void Run() {
-      group_->ExecuteInThread();
-    }
-
-   private:
-    SourceGroup* group_;
-  };
-
-  void ExecuteInThread() {
-    v8::Isolate* isolate = v8::Isolate::New();
-    do {
-      if (next_semaphore_ != NULL) next_semaphore_->Wait();
-      {
-        v8::Isolate::Scope iscope(isolate);
-        v8::HandleScope scope;
-        v8::Persistent<v8::Context> context = CreateShellContext();
-        {
-          v8::Context::Scope cscope(context);
-          Execute();
-        }
-        context.Dispose();
-      }
-      if (done_semaphore_ != NULL) done_semaphore_->Signal();
-    } while (!last_run);
-    isolate->Dispose();
-  }
-
-  v8::internal::Semaphore* next_semaphore_;
-  v8::internal::Semaphore* done_semaphore_;
-  v8::internal::Thread* thread_;
-#endif  // USING_V8_SHARED
-
-  const char** argv_;
-  int begin_offset_;
-  int end_offset_;
-};
+static bool run_shell;
 
 
-static SourceGroup* isolate_sources = NULL;
-
-
-#ifdef COMPRESS_STARTUP_DATA_BZ2
-class BZip2Decompressor : public v8::StartupDataDecompressor {
- public:
-  virtual ~BZip2Decompressor() { }
-
- protected:
-  virtual int DecompressData(char* raw_data,
-                             int* raw_data_size,
-                             const char* compressed_data,
-                             int compressed_data_size) {
-    ASSERT_EQ(v8::StartupData::kBZip2,
-              v8::V8::GetCompressedStartupDataAlgorithm());
-    unsigned int decompressed_size = *raw_data_size;
-    int result =
-        BZ2_bzBuffToBuffDecompress(raw_data,
-                                   &decompressed_size,
-                                   const_cast<char*>(compressed_data),
-                                   compressed_data_size,
-                                   0, 1);
-    if (result == BZ_OK) {
-      *raw_data_size = decompressed_size;
-    }
-    return result;
-  }
-};
-#endif
-
-
-int RunMain(int argc, char* argv[]) {
+int main(int argc, char* argv[]) {
   v8::V8::SetFlagsFromCommandLine(&argc, argv, true);
+  run_shell = (argc == 1);
   v8::HandleScope handle_scope;
   v8::Persistent<v8::Context> context = CreateShellContext();
-  // Enter the newly created execution environment.
-  context->Enter();
   if (context.IsEmpty()) {
     printf("Error creating context\n");
     return 1;
   }
-
-  bool run_shell = (argc == 1);
-  int num_isolates = 1;
-  for (int i = 1; i < argc; i++) {
-    if (strcmp(argv[i], "--isolate") == 0) {
-#if !(defined(USING_V8_SHARED) || defined(V8_SHARED))
-      ++num_isolates;
-#else  // USING_V8_SHARED
-      printf("Error: --isolate not supported when linked with shared "
-             "library\n");
-      ExitShell(1);
-#endif  // USING_V8_SHARED
-    }
-  }
-  if (isolate_sources == NULL) {
-    isolate_sources = new SourceGroup[num_isolates];
-    SourceGroup* current = isolate_sources;
-    current->Begin(argv, 1);
-    for (int i = 1; i < argc; i++) {
-      const char* str = argv[i];
-      if (strcmp(str, "--isolate") == 0) {
-        current->End(i);
-        current++;
-        current->Begin(argv, i + 1);
-      } else if (strcmp(str, "--shell") == 0) {
-        run_shell = true;
-      } else if (strcmp(str, "-f") == 0) {
-        // Ignore any -f flags for compatibility with the other stand-
-        // alone JavaScript engines.
-        continue;
-      } else if (strncmp(str, "--", 2) == 0) {
-        printf("Warning: unknown flag %s.\nTry --help for options\n", str);
-      }
-    }
-    current->End(argc);
-  }
-#if !(defined(USING_V8_SHARED) || defined(V8_SHARED))
-  for (int i = 1; i < num_isolates; ++i) {
-    isolate_sources[i].StartExecuteInThread();
-  }
-#endif  // USING_V8_SHARED
-  isolate_sources[0].Execute();
+  context->Enter();
+  int result = RunMain(argc, argv);
   if (run_shell) RunShell(context);
-#if !(defined(USING_V8_SHARED) || defined(V8_SHARED))
-  for (int i = 1; i < num_isolates; ++i) {
-    isolate_sources[i].WaitForThread();
-  }
-#endif  // USING_V8_SHARED
-  if (last_run) {
-    delete[] isolate_sources;
-    isolate_sources = NULL;
-  }
   context->Exit();
   context.Dispose();
-  return 0;
-}
-
-
-int main(int argc, char* argv[]) {
-  // Figure out if we're requested to stress the optimization
-  // infrastructure by running tests multiple times and forcing
-  // optimization in the last run.
-  bool FLAG_stress_opt = false;
-  bool FLAG_stress_deopt = false;
-  for (int i = 0; i < argc; i++) {
-    if (strcmp(argv[i], "--stress-opt") == 0) {
-      FLAG_stress_opt = true;
-      argv[i] = NULL;
-    } else if (strcmp(argv[i], "--stress-deopt") == 0) {
-      FLAG_stress_deopt = true;
-      argv[i] = NULL;
-    } else if (strcmp(argv[i], "--noalways-opt") == 0) {
-      // No support for stressing if we can't use --always-opt.
-      FLAG_stress_opt = false;
-      FLAG_stress_deopt = false;
-      break;
-    }
-  }
-
-#ifdef COMPRESS_STARTUP_DATA_BZ2
-  BZip2Decompressor startup_data_decompressor;
-  int bz2_result = startup_data_decompressor.Decompress();
-  if (bz2_result != BZ_OK) {
-    fprintf(stderr, "bzip error code: %d\n", bz2_result);
-    exit(1);
-  }
-#endif
-
-  v8::V8::SetFlagsFromCommandLine(&argc, argv, true);
-  int result = 0;
-  if (FLAG_stress_opt || FLAG_stress_deopt) {
-    v8::Testing::SetStressRunType(FLAG_stress_opt
-                                  ? v8::Testing::kStressTypeOpt
-                                  : v8::Testing::kStressTypeDeopt);
-    int stress_runs = v8::Testing::GetStressRuns();
-    for (int i = 0; i < stress_runs && result == 0; i++) {
-      printf("============ Stress %d/%d ============\n",
-             i + 1, stress_runs);
-      v8::Testing::PrepareStressRun(i);
-      last_run = (i == stress_runs - 1);
-      result = RunMain(argc, argv);
-    }
-    printf("======== Full Deoptimization =======\n");
-    v8::Testing::DeoptimizeAll();
-  } else {
-    result = RunMain(argc, argv);
-  }
   v8::V8::Dispose();
-
   return result;
 }
 
 
 // Extracts a C string from a V8 Utf8Value.
 const char* ToCString(const v8::String::Utf8Value& value) {
   return *value ? *value : "<string conversion failed>";
 }
 
 
 // Creates a new execution environment containing the built-in
 // functions.
 v8::Persistent<v8::Context> CreateShellContext() {
   // Create a template for the global object.
   v8::Handle<v8::ObjectTemplate> global = v8::ObjectTemplate::New();
   // Bind the global 'print' function to the C++ Print callback.
   global->Set(v8::String::New("print"), v8::FunctionTemplate::New(Print));
   // Bind the global 'read' function to the C++ Read callback.
   global->Set(v8::String::New("read"), v8::FunctionTemplate::New(Read));
   // Bind the global 'load' function to the C++ Load callback.
   global->Set(v8::String::New("load"), v8::FunctionTemplate::New(Load));
   // Bind the 'quit' function
   global->Set(v8::String::New("quit"), v8::FunctionTemplate::New(Quit));
   // Bind the 'version' function
   global->Set(v8::String::New("version"), v8::FunctionTemplate::New(Version));
 
-  // Bind the handlers for external arrays.
-  global->Set(v8::String::New("Int8Array"),
-              v8::FunctionTemplate::New(Int8Array));
-  global->Set(v8::String::New("Uint8Array"),
-              v8::FunctionTemplate::New(Uint8Array));
-  global->Set(v8::String::New("Int16Array"),
-              v8::FunctionTemplate::New(Int16Array));
-  global->Set(v8::String::New("Uint16Array"),
-              v8::FunctionTemplate::New(Uint16Array));
-  global->Set(v8::String::New("Int32Array"),
-              v8::FunctionTemplate::New(Int32Array));
-  global->Set(v8::String::New("Uint32Array"),
-              v8::FunctionTemplate::New(Uint32Array));
-  global->Set(v8::String::New("Float32Array"),
-              v8::FunctionTemplate::New(Float32Array));
-  global->Set(v8::String::New("Float64Array"),
-              v8::FunctionTemplate::New(Float64Array));
-  global->Set(v8::String::New("PixelArray"),
-              v8::FunctionTemplate::New(PixelArray));
-
   return v8::Context::New(NULL, global);
 }
 
 
 // The callback that is invoked by v8 whenever the JavaScript 'print'
 // function is called.  Prints its arguments on stdout separated by
 // spaces and ending with a newline.
 v8::Handle<v8::Value> Print(const v8::Arguments& args) {
   bool first = true;
   for (int i = 0; i < args.Length(); i++) {
@@ skipping 53 matching lines @@
   return v8::Undefined();
 }
 
 
 // The callback that is invoked by v8 whenever the JavaScript 'quit'
 // function is called.  Quits.
 v8::Handle<v8::Value> Quit(const v8::Arguments& args) {
   // If not arguments are given args[0] will yield undefined which
   // converts to the integer value 0.
   int exit_code = args[0]->Int32Value();
-  ExitShell(exit_code);
+  fflush(stdout);
+  fflush(stderr);
+  exit(exit_code);
   return v8::Undefined();
 }
 
 
 v8::Handle<v8::Value> Version(const v8::Arguments& args) {
   return v8::String::New(v8::V8::GetVersion());
 }
 
 
-void ExternalArrayWeakCallback(v8::Persistent<v8::Value> object, void* data) {
-  free(data);
-  object.Dispose();
-}
-
-
-v8::Handle<v8::Value> CreateExternalArray(const v8::Arguments& args,
-                                          v8::ExternalArrayType type,
-                                          size_t element_size) {
-  assert(element_size == 1 ||
-         element_size == 2 ||
-         element_size == 4 ||
-         element_size == 8);
-  if (args.Length() != 1) {
-    return v8::ThrowException(
-        v8::String::New("Array constructor needs one parameter."));
-  }
-  static const int kMaxLength = 0x3fffffff;
-  size_t length = 0;
-  if (args[0]->IsUint32()) {
-    length = args[0]->Uint32Value();
-  } else if (args[0]->IsNumber()) {
-    double raw_length = args[0]->NumberValue();
-    if (raw_length < 0) {
-      return v8::ThrowException(
-          v8::String::New("Array length must not be negative."));
-    }
-    if (raw_length > kMaxLength) {
-      return v8::ThrowException(
-          v8::String::New("Array length exceeds maximum length."));
-    }
-    length = static_cast<size_t>(raw_length);
-  } else {
-    return v8::ThrowException(
-        v8::String::New("Array length must be a number."));
-  }
-  if (length > static_cast<size_t>(kMaxLength)) {
-    return v8::ThrowException(
-        v8::String::New("Array length exceeds maximum length."));
-  }
-  void* data = calloc(length, element_size);
-  if (data == NULL) {
-    return v8::ThrowException(v8::String::New("Memory allocation failed."));
-  }
-  v8::Handle<v8::Object> array = v8::Object::New();
-  v8::Persistent<v8::Object> persistent_array =
-      v8::Persistent<v8::Object>::New(array);
-  persistent_array.MakeWeak(data, ExternalArrayWeakCallback);
-  persistent_array.MarkIndependent();
-  array->SetIndexedPropertiesToExternalArrayData(data, type, length);
-  array->Set(v8::String::New("length"), v8::Int32::New(length),
-             v8::ReadOnly);
-  array->Set(v8::String::New("BYTES_PER_ELEMENT"),
-             v8::Int32::New(element_size));
-  return array;
-}
-
-
-v8::Handle<v8::Value> Int8Array(const v8::Arguments& args) {
-  return CreateExternalArray(args, v8::kExternalByteArray, sizeof(int8_t));
-}
-
-
-v8::Handle<v8::Value> Uint8Array(const v8::Arguments& args) {
-  return CreateExternalArray(args, v8::kExternalUnsignedByteArray,
-                             sizeof(uint8_t));
-}
-
-
-v8::Handle<v8::Value> Int16Array(const v8::Arguments& args) {
-  return CreateExternalArray(args, v8::kExternalShortArray, sizeof(int16_t));
-}
-
-
-v8::Handle<v8::Value> Uint16Array(const v8::Arguments& args) {
-  return CreateExternalArray(args, v8::kExternalUnsignedShortArray,
-                             sizeof(uint16_t));
-}
-
-v8::Handle<v8::Value> Int32Array(const v8::Arguments& args) {
-  return CreateExternalArray(args, v8::kExternalIntArray, sizeof(int32_t));
-}
-
-
-v8::Handle<v8::Value> Uint32Array(const v8::Arguments& args) {
-  return CreateExternalArray(args, v8::kExternalUnsignedIntArray,
-                             sizeof(uint32_t));
-}
-
-
-v8::Handle<v8::Value> Float32Array(const v8::Arguments& args) {
-  return CreateExternalArray(args, v8::kExternalFloatArray,
-                             sizeof(float));  // NOLINT
-}
-
-
-v8::Handle<v8::Value> Float64Array(const v8::Arguments& args) {
-  return CreateExternalArray(args, v8::kExternalDoubleArray,
-                             sizeof(double));  // NOLINT
-}
-
-
-v8::Handle<v8::Value> PixelArray(const v8::Arguments& args) {
-  return CreateExternalArray(args, v8::kExternalPixelArray, sizeof(uint8_t));
-}
-
-
 // Reads a file into a v8 string.
 v8::Handle<v8::String> ReadFile(const char* name) {
   FILE* file = fopen(name, "rb");
   if (file == NULL) return v8::Handle<v8::String>();
 
   fseek(file, 0, SEEK_END);
   int size = ftell(file);
   rewind(file);
 
   char* chars = new char[size + 1];
   chars[size] = '\0';
   for (int i = 0; i < size;) {
     int read = fread(&chars[i], 1, size - i, file);
     i += read;
   }
   fclose(file);
   v8::Handle<v8::String> result = v8::String::New(chars, size);
   delete[] chars;
   return result;
 }
 
 
+// Process remaining command line arguments and execute files
+int RunMain(int argc, char* argv[]) {
+  for (int i = 1; i < argc; i++) {
+    const char* str = argv[i];
+    if (strcmp(str, "--shell") == 0) {
+      run_shell = true;
+    } else if (strcmp(str, "-f") == 0) {
+      // Ignore any -f flags for compatibility with the other stand-
+      // alone JavaScript engines.
+      continue;
+    } else if (strncmp(str, "--", 2) == 0) {
+      printf("Warning: unknown flag %s.\nTry --help for options\n", str);
+    } else if (strcmp(str, "-e") == 0 && i + 1 < argc) {
+      // Execute argument given to -e option directly.
+      v8::Handle<v8::String> file_name = v8::String::New("unnamed");
+      v8::Handle<v8::String> source = v8::String::New(argv[++i]);
+      if (!ExecuteString(source, file_name, false, true)) return 1;
+    } else {
+      // Use all other arguments as names of files to load and run.
+      v8::Handle<v8::String> file_name = v8::String::New(str);
+      v8::Handle<v8::String> source = ReadFile(str);
+      if (source.IsEmpty()) {
+        printf("Error reading '%s'\n", str);
+        continue;
+      }
+      if (!ExecuteString(source, file_name, false, true)) return 1;
+    }
+  }
+  return 0;
+}
+
+
 // The read-eval-execute loop of the shell.
 void RunShell(v8::Handle<v8::Context> context) {
-  printf("V8 version %s\n", v8::V8::GetVersion());
+  printf("V8 version %s [sample shell]\n", v8::V8::GetVersion());
   static const int kBufferSize = 256;
   // Enter the execution environment before evaluating any code.
   v8::Context::Scope context_scope(context);
   while (true) {
     char buffer[kBufferSize];
     printf("> ");
     char* str = fgets(buffer, kBufferSize, stdin);
     if (str == NULL) break;
     v8::HandleScope handle_scope;
     ExecuteString(v8::String::New(str),
@@ skipping 70 matching lines @@
       printf("^");
     }
     printf("\n");
     v8::String::Utf8Value stack_trace(try_catch->StackTrace());
     if (stack_trace.length() > 0) {
       const char* stack_trace_string = ToCString(stack_trace);
       printf("%s\n", stack_trace_string);
     }
   }
 }