Added first shot at a development shell

src/d8.cc

Index: src/d8.cc
diff --git a/src/d8.cc b/src/d8.cc
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+// Copyright 2008 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 "d8.h"
+#include "debug.h"
+#include "api.h"
+#include "natives.h"
+
+
+namespace v8 {
+
+
+const char* Shell::kHistoryFileName = ".d8_history";
+const char* Shell::kPrompt = "d8> ";
+
+
+LineEditor *LineEditor::first_ = NULL;
+
+
+LineEditor::LineEditor(Type type, const char* name)
+    : type_(type),
+      name_(name),
+      next_(first_) {
+  first_ = this;
+}
+
+
+LineEditor* LineEditor::Get() {
+  LineEditor* current = first_;
+  LineEditor* best = current;
+  while (current != NULL) {
+    if (current->type_ > best->type_)
+      best = current;
+    current = current->next_;
+  }
+  return best;
+}
+
+
+class DumbLineEditor: public LineEditor {
+ public:
+  DumbLineEditor() : LineEditor(LineEditor::DUMB, "dumb") { }
+  virtual i::SmartPointer<char> Prompt(const char* prompt);
+};
+
+
+static DumbLineEditor dumb_line_editor;
+
+
+i::SmartPointer<char> DumbLineEditor::Prompt(const char* prompt) {
+  static const int kBufferSize = 256;
+  char buffer[kBufferSize];
+  printf("%s", prompt);
+  char* str = fgets(buffer, kBufferSize, stdin);
+  return i::SmartPointer<char>(str ? i::OS::StrDup(str) : str);
+}
+
+
+Shell::CounterMap Shell::counter_map_;
+Persistent<Context> Shell::utility_context_;
+Persistent<Context> Shell::evaluation_context_;
+
+
+// Executes a string within the current v8 context.
+bool Shell::ExecuteString(Handle<String> source,
+                          Handle<Value> name,
+                          bool print_result,
+                          bool report_exceptions) {
+  HandleScope handle_scope;
+  TryCatch try_catch;
+  Handle<Script> script = Script::Compile(source, name);
+  if (script.IsEmpty()) {
+    // Print errors that happened during compilation.
+    if (report_exceptions)
+      ReportException(&try_catch);
+    return false;
+  } else {
+    Handle<Value> result = script->Run();
+    if (result.IsEmpty()) {
+      // Print errors that happened during execution.
+      if (report_exceptions)
+        ReportException(&try_catch);
+      return false;
+    } else {
+      if (print_result && !result->IsUndefined()) {
+        // If all went well and the result wasn't undefined then print
+        // the returned value.
+        String::Utf8Value str(result);
+        printf("%s\n", *str);
+      }
+      return true;
+    }
+  }
+}
+
+
+Handle<Value> Shell::Print(const Arguments& args) {
+  bool first = true;
+  for (int i = 0; i < args.Length(); i++) {
+    HandleScope handle_scope;
+    if (first) {
+      first = false;
+    } else {
+      printf(" ");
+    }
+    String::Utf8Value str(args[i]);
+    printf("%s", *str);
+  }
+  printf("\n");
+  return Undefined();
+}
+
+
+Handle<Value> Shell::Load(const Arguments& args) {
+  for (int i = 0; i < args.Length(); i++) {
+    HandleScope handle_scope;
+    String::Utf8Value file(args[i]);
+    Handle<String> source = ReadFile(*file);
+    if (source.IsEmpty()) {
+      return ThrowException(String::New("Error loading file"));
+    }
+    if (!ExecuteString(source, String::New(*file), false, false)) {
+      return ThrowException(String::New("Error executing  file"));
+    }
+  }
+  return Undefined();
+}
+
+
+Handle<Value> Shell::Quit(const Arguments& args) {
+  int exit_code = args[0]->Int32Value();
+  OnExit();
+  exit(exit_code);
+  return Undefined();
+}
+
+
+Handle<Value> Shell::Version(const Arguments& args) {
+  return String::New(V8::GetVersion());
+}
+
+
+void Shell::ReportException(v8::TryCatch* try_catch) {
+  HandleScope handle_scope;
+  String::Utf8Value exception(try_catch->Exception());
+  Handle<Message> message = try_catch->Message();
+  if (message.IsEmpty()) {
+    // V8 didn't provide any extra information about this error; just
+    // print the exception.
+    printf("%s\n", *exception);
+  } else {
+    // Print (filename):(line number): (message).
+    String::Utf8Value filename(message->GetScriptResourceName());
+    int linenum = message->GetLineNumber();
+    printf("%s:%i: %s\n", *filename, linenum, *exception);
+    // Print line of source code.
+    String::Utf8Value sourceline(message->GetSourceLine());
+    printf("%s\n", *sourceline);
+    // Print wavy underline (GetUnderline is deprecated).
+    int start = message->GetStartColumn();
+    for (int i = 0; i < start; i++) {
+      printf(" ");
+    }
+    int end = message->GetEndColumn();
+    for (int i = start; i < end; i++) {
+      printf("^");
+    }
+    printf("\n");
+  }
+}
+
+
+Handle<Array> Shell::GetCompletions(Handle<String> text, Handle<String> full) {
+  HandleScope handle_scope;
+  Context::Scope context_scope(utility_context_);
+  Handle<Object> global = utility_context_->Global();
+  Handle<Value> fun = global->Get(String::New("GetCompletions"));
+  static const int kArgc = 3;
+  Handle<Value> argv[kArgc] = { evaluation_context_->Global(), text, full };
+  Handle<Value> val = Handle<Function>::Cast(fun)->Call(global, kArgc, argv);
+  return handle_scope.Close(Handle<Array>::Cast(val));
+}
+
+
+int* Shell::LookupCounter(const wchar_t* name) {
+  CounterMap::iterator item = counter_map_.find(name);
+  if (item != counter_map_.end()) {
+    Counter* result = (*item).second;
+    return result->GetValuePtr();
+  }
+  Counter* result = new Counter(name);
+  counter_map_[name] = result;
+  return result->GetValuePtr();
+}
+
+
+void Shell::Initialize() {
+  // Set up counters
+  if (i::FLAG_dump_counters)
+    V8::SetCounterFunction(LookupCounter);
+  // Initialize the global objects
+  HandleScope scope;
+  Handle<ObjectTemplate> global_template = ObjectTemplate::New();
+  global_template->Set(String::New("print"), FunctionTemplate::New(Print));
+  global_template->Set(String::New("load"), FunctionTemplate::New(Load));
+  global_template->Set(String::New("quit"), FunctionTemplate::New(Quit));
+  global_template->Set(String::New("version"), FunctionTemplate::New(Version));
+
+  utility_context_ = Context::New(NULL, global_template);
+  utility_context_->SetSecurityToken(Undefined());
+  Context::Scope utility_scope(utility_context_);
+
+  // Install the debugger object in the utility scope
+  i::Debug::Load();
+  i::JSObject* raw_debug = i::Debug::debug_context()->global();
+  i::JSGlobalObject* debug = i::JSGlobalObject::cast(raw_debug);
+  debug->set_security_token(i::Heap::undefined_value());
+  utility_context_->Global()->Set(String::New("$debug"),
+                                  Utils::ToLocal(&raw_debug));
+
+  // Run the d8 shell utility script in the utility context
+  int source_index = i::NativesCollection<i::D8>::GetIndex("d8");
+  i::Vector<const char> shell_source
+      = i::NativesCollection<i::D8>::GetScriptSource(source_index);
+  i::Vector<const char> shell_source_name
+      = i::NativesCollection<i::D8>::GetScriptName(source_index);
+  Handle<String> source = String::New(shell_source.start(),
+                                      shell_source.length());
+  Handle<String> name = String::New(shell_source_name.start(),
+                                    shell_source_name.length());
+  Script::Compile(source, name)->Run();
+
+  // Create the evaluation context
+  evaluation_context_ = Context::New(NULL, global_template);
+  evaluation_context_->SetSecurityToken(Undefined());
+}
+
+
+void Shell::OnExit() {
+  if (i::FLAG_dump_counters) {
+    ::printf("+----------------------------------------+----------+\n");
+    ::printf("| Name                                   | Value    |\n");
+    ::printf("+----------------------------------------+----------+\n");
+    for (CounterMap::iterator i = counter_map_.begin();
+         i != counter_map_.end();
+         i++) {
+      Counter* counter = (*i).second;
+      ::printf("| %-38ls | %8i |\n", counter->name(), counter->value());
+    }
+    ::printf("+----------------------------------------+----------+\n");
+  }
+}
+
+
+// Reads a file into a v8 string.
+Handle<String> Shell::ReadFile(const char* name) {
+  FILE* file = i::OS::FOpen(name, "rb");
+  if (file == NULL) return Handle<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);
+  Handle<String> result = String::New(chars, size);
+  delete[] chars;
+  return result;
+}
+
+
+void Shell::RunShell() {
+  LineEditor* editor = LineEditor::Get();
+  printf("V8 version %s [console: %s]\n", V8::GetVersion(), editor->name());
+  editor->Open();
+  while (true) {
+    HandleScope handle_scope;
+    i::SmartPointer<char> input = editor->Prompt(Shell::kPrompt);
+    if (input.is_empty())
+      break;
+    editor->AddHistory(*input);
+    Handle<String> name = String::New("(d8)");
+    ExecuteString(String::New(*input), name, true, true);
+  }
+  editor->Close();
+  printf("\n");
+}
+
+
+int Shell::Main(int argc, char* argv[]) {
+  i::FlagList::SetFlagsFromCommandLine(&argc, argv, true);
+  Initialize();
+  bool run_shell = (argc == 1);
+  Context::Scope context_scope(evaluation_context_);
+  for (int i = 1; i < argc; i++) {
+    char* str = argv[i];
+    HandleScope handle_scope;
+    Handle<String> file_name = v8::String::New(str);
+    Handle<String> source = ReadFile(str);
+    if (source.IsEmpty()) {
+      printf("Error reading '%s'\n", str);
+      return 1;
+    }
+    if (!ExecuteString(source, file_name, false, true))
+      return 1;
+  }
+  if (run_shell)
+    RunShell();
+  OnExit();
+  return 0;
+}
+}  // v8
+
+
+int main(int argc, char* argv[]) {
+  return v8::Shell::Main(argc, argv);
+}