[d8] remove utility context.

We only use it to store the Stringify function to format
REPL output. This is overkill and introduces issues with
security tokens.

R=jochen@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1845833002

Cr-Commit-Position: refs/heads/master@{#35158}

src/d8.cc

@@ -251,7 +251,7 @@ CounterCollection* Shell::counters_ = &local_counters_;
 base::LazyMutex Shell::context_mutex_;
 const base::TimeTicks Shell::kInitialTicks =
     base::TimeTicks::HighResolutionNow();
-Global<Context> Shell::utility_context_;
+Global<Function> Shell::stringify_function_;
 base::LazyMutex Shell::workers_mutex_;
 bool Shell::allow_new_workers_ = true;
 i::List<Worker*> Shell::workers_;
@@ -412,24 +412,7 @@ bool Shell::ExecuteString(Isolate* isolate, Local<String> source,
       }
 #if !defined(V8_SHARED)
     } else {
-      v8::TryCatch try_catch(isolate);
-      v8::Local<v8::Context> context =
-          v8::Local<v8::Context>::New(isolate, utility_context_);
-      v8::Context::Scope context_scope(context);
-      Local<Object> global = context->Global();
-      Local<Value> fun =
-          global->Get(context, String::NewFromUtf8(isolate, "Stringify",
-                                                   v8::NewStringType::kNormal)
-                                   .ToLocalChecked()).ToLocalChecked();
-      Local<Value> argv[1] = {result};
-      Local<Value> s;
-      if (!Local<Function>::Cast(fun)
-               ->Call(context, global, 1, argv)
-               .ToLocal(&s)) {
-        return true;
-      }
-      DCHECK(!try_catch.HasCaught());
-      v8::String::Utf8Value str(s);
+      v8::String::Utf8Value str(Stringify(isolate, result));
       fwrite(*str, sizeof(**str), str.length(), stdout);
       printf("\n");
     }
@@ -906,11 +889,11 @@ void Shell::Version(const v8::FunctionCallbackInfo<v8::Value>& args) {
 void Shell::ReportException(Isolate* isolate, v8::TryCatch* try_catch) {
   HandleScope handle_scope(isolate);
 #ifndef V8_SHARED
-  Local<Context> utility_context;
+  Local<Context> context;
   bool enter_context = !isolate->InContext();
   if (enter_context) {
-    utility_context = Local<Context>::New(isolate, utility_context_);
-    utility_context->Enter();
+    context = Local<Context>::New(isolate, evaluation_context_);
+    context->Enter();
   }
 #endif  // !V8_SHARED
   v8::String::Utf8Value exception(try_catch->Exception());
@@ -954,7 +937,7 @@ void Shell::ReportException(Isolate* isolate, v8::TryCatch* try_catch) {
   }
   printf("\n");
 #ifndef V8_SHARED
-  if (enter_context) utility_context->Exit();
+  if (enter_context) context->Exit();
 #endif  // !V8_SHARED
 }
 
@@ -1057,47 +1040,37 @@ void Shell::AddHistogramSample(void* histogram, int sample) {
   counter->AddSample(sample);
 }
 
-
-void Shell::InstallUtilityScript(Isolate* isolate) {
-  HandleScope scope(isolate);
-  // If we use the utility context, we have to set the security tokens so that
-  // utility, evaluation and debug context can all access each other.
-  Local<ObjectTemplate> global_template = CreateGlobalTemplate(isolate);
-  utility_context_.Reset(isolate, Context::New(isolate, NULL, global_template));
-  v8::Local<v8::Context> utility_context =
-      v8::Local<v8::Context>::New(isolate, utility_context_);
-  v8::Local<v8::Context> evaluation_context =
+// Turn a value into a human-readable string.
+Local<String> Shell::Stringify(Isolate* isolate, Local<Value> value) {
+  v8::Local<v8::Context> context =
       v8::Local<v8::Context>::New(isolate, evaluation_context_);
-  utility_context->SetSecurityToken(Undefined(isolate));
-  evaluation_context->SetSecurityToken(Undefined(isolate));
-  v8::Context::Scope context_scope(utility_context);
-
-  // Run the d8 shell utility script in the utility context
+  if (stringify_function_.IsEmpty()) {
     int source_index = i::NativesCollection<i::D8>::GetIndex("d8");
-  i::Vector<const char> shell_source =
+    i::Vector<const char> source_string =
         i::NativesCollection<i::D8>::GetScriptSource(source_index);
-  i::Vector<const char> shell_source_name =
+    i::Vector<const char> source_name =
         i::NativesCollection<i::D8>::GetScriptName(source_index);
     Local<String> source =
-      String::NewFromUtf8(isolate, shell_source.start(), NewStringType::kNormal,
-                          shell_source.length()).ToLocalChecked();
+        String::NewFromUtf8(isolate, source_string.start(),
+                            NewStringType::kNormal, source_string.length())
+            .ToLocalChecked();
     Local<String> name =
-      String::NewFromUtf8(isolate, shell_source_name.start(),
-                          NewStringType::kNormal,
-                          shell_source_name.length()).ToLocalChecked();
+        String::NewFromUtf8(isolate, source_name.start(),
+                            NewStringType::kNormal, source_name.length())
+            .ToLocalChecked();
     ScriptOrigin origin(name);
     Local<Script> script =
-      Script::Compile(utility_context, source, &origin).ToLocalChecked();
-  script->Run(utility_context).ToLocalChecked();
-  // Mark the d8 shell script as native to avoid it showing up as normal source
-  // in the debugger.
-  i::Handle<i::Object> compiled_script = Utils::OpenHandle(*script);
-  i::Handle<i::Script> script_object = compiled_script->IsJSFunction()
-      ? i::Handle<i::Script>(i::Script::cast(
-          i::JSFunction::cast(*compiled_script)->shared()->script()))
-      : i::Handle<i::Script>(i::Script::cast(
-          i::SharedFunctionInfo::cast(*compiled_script)->script()));
-  script_object->set_type(i::Script::TYPE_EXTENSION);
+        Script::Compile(context, source, &origin).ToLocalChecked();
+    stringify_function_.Reset(
+        isolate, script->Run(context).ToLocalChecked().As<Function>());
+  }
+  Local<Function> fun = Local<Function>::New(isolate, stringify_function_);
+  Local<Value> argv[1] = {value};
+  v8::TryCatch try_catch(isolate);
+  MaybeLocal<Value> result =
+      fun->Call(context, Undefined(isolate), 1, argv).ToLocalChecked();
+  if (result.IsEmpty()) return String::Empty(isolate);
+  return result.ToLocalChecked().As<String>();
 }
 #endif  // !V8_SHARED
 
@@ -2220,8 +2193,6 @@ MaybeLocal<Value> Shell::DeserializeValue(Isolate* isolate,
                                           int* offset) {
   DCHECK(offset);
   EscapableHandleScope scope(isolate);
-  // This function should not use utility_context_ because it is running on a
-  // different thread.
   Local<Value> result;
   SerializationTag tag = data.ReadTag(offset);
 
@@ -2502,17 +2473,11 @@ int Shell::Main(int argc, char* argv[]) {
     // Run interactive shell if explicitly requested or if no script has been
     // executed, but never on --test
     if (options.use_interactive_shell()) {
-#ifndef V8_SHARED
-      InstallUtilityScript(isolate);
-#endif  // !V8_SHARED
       RunShell(isolate);
     }
 
     // Shut down contexts and collect garbage.
     evaluation_context_.Reset();
-#ifndef V8_SHARED
-    utility_context_.Reset();
-#endif  // !V8_SHARED
     CollectGarbage(isolate);
   }
   OnExit(isolate);

src/d8.h

@@ -446,7 +446,7 @@ class Shell : public i::AllStatic {
   static Global<Context> evaluation_context_;
   static base::OnceType quit_once_;
 #ifndef V8_SHARED
-  static Global<Context> utility_context_;
+  static Global<Function> stringify_function_;
   static CounterMap* counter_map_;
   // We statically allocate a set of local counters to be used if we
   // don't want to store the stats in a memory-mapped file
@@ -462,7 +462,7 @@ class Shell : public i::AllStatic {
   static i::List<SharedArrayBuffer::Contents> externalized_shared_contents_;
 
   static Counter* GetCounter(const char* name, bool is_histogram);
-  static void InstallUtilityScript(Isolate* isolate);
+  static Local<String> Stringify(Isolate* isolate, Local<Value> value);
 #endif  // !V8_SHARED
   static void Initialize(Isolate* isolate);
   static void RunShell(Isolate* isolate);

src/d8.js

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+(function() {
 "use strict";
 
 // A more universal stringify that supports more types than JSON.
@@ -89,3 +90,6 @@ function StringifyProxy(proxy, depth) {
   }
   return '[' + proxy_type + ' Proxy ' + Stringify(info_object, depth-1) + ']';
 }
+
+return Stringify;
+})();