[inspector] always include user scripts in the snapshot.

V8 can bundle user scripts in the start up snapshot. These are
shared across contexts, and do not work well context groups.

R=kozyatinskiy@chromium.org
BUG=v8:6274

Review-Url: https://codereview.chromium.org/2836623002
Cr-Commit-Position: refs/heads/master@{#44847}

src/api.cc

@@ -9287,6 +9287,11 @@ bool debug::Script::WasCompiled() const {
          i::Script::COMPILATION_STATE_COMPILED;
 }
 
+bool debug::Script::IsEmbedded() const {
+  i::Handle<i::Script> script = Utils::OpenHandle(this);
+  return script->context_data() == script->GetHeap()->uninitialized_symbol();
+}
+
 int debug::Script::Id() const { return Utils::OpenHandle(this)->id(); }
 
 int debug::Script::LineOffset() const {
@@ -9343,12 +9348,13 @@ MaybeLocal<String> debug::Script::SourceMappingURL() const {
       handle_scope.CloseAndEscape(i::Handle<i::String>::cast(value)));
 }
 
-MaybeLocal<Value> debug::Script::ContextData() const {
+Maybe<int> debug::Script::ContextId() const {
   i::Isolate* isolate = Utils::OpenHandle(this)->GetIsolate();
   i::HandleScope handle_scope(isolate);
   i::Handle<i::Script> script = Utils::OpenHandle(this);
-  i::Handle<i::Object> value(script->context_data(), isolate);
-  return Utils::ToLocal(handle_scope.CloseAndEscape(value));
+  i::Object* value = script->context_data();
+  if (value->IsSmi()) return Just(i::Smi::cast(value)->value());
+  return Nothing<int>();
 }
 
 MaybeLocal<String> debug::Script::Source() const {

src/debug/debug-interface.h

@@ -129,6 +129,7 @@ class V8_EXPORT_PRIVATE Script {
 
   ScriptOriginOptions OriginOptions() const;
   bool WasCompiled() const;
+  bool IsEmbedded() const;
   int Id() const;
   int LineOffset() const;
   int ColumnOffset() const;
@@ -136,7 +137,7 @@ class V8_EXPORT_PRIVATE Script {
   MaybeLocal<String> Name() const;
   MaybeLocal<String> SourceURL() const;
   MaybeLocal<String> SourceMappingURL() const;
-  MaybeLocal<Value> ContextData() const;
+  Maybe<int> ContextId() const;
   MaybeLocal<String> Source() const;
   bool IsWasm() const;
   bool IsModule() const;

src/inspector/v8-debugger-script.cc

@@ -138,11 +138,7 @@ class ActualScript : public V8DebuggerScript {
       m_endColumn = m_startColumn;
     }
 
-    v8::Local<v8::Value> contextData;
-    if (script->ContextData().ToLocal(&contextData) && contextData->IsInt32()) {
-      m_executionContextId =
-          static_cast<int>(contextData.As<v8::Int32>()->Value());
-    }
+    USE(script->ContextId().To(&m_executionContextId));
 
     if (script->Source().ToLocal(&tmp)) {
       m_source = toProtocolString(tmp);

src/inspector/v8-debugger.cc

@@ -29,11 +29,8 @@ inline v8::Local<v8::Boolean> v8Boolean(bool value, v8::Isolate* isolate) {
 
 V8DebuggerAgentImpl* agentForScript(V8InspectorImpl* inspector,
                                     v8::Local<v8::debug::Script> script) {
-  v8::Local<v8::Value> contextData;
-  if (!script->ContextData().ToLocal(&contextData) || !contextData->IsInt32()) {
-    return nullptr;
-  }
-  int contextId = static_cast<int>(contextData.As<v8::Int32>()->Value());
+  int contextId;
+  if (!script->ContextId().To(&contextId)) return nullptr;
   int contextGroupId = inspector->contextGroupId(contextId);
   if (!contextGroupId) return nullptr;
   return inspector->enabledDebuggerAgentForGroup(contextGroupId);
@@ -219,10 +216,12 @@ void V8Debugger::getCompiledScripts(
   for (size_t i = 0; i < scripts.Size(); ++i) {
     v8::Local<v8::debug::Script> script = scripts.Get(i);
     if (!script->WasCompiled()) continue;
-    v8::Local<v8::Value> contextData;
-    if (!script->ContextData().ToLocal(&contextData) || !contextData->IsInt32())
+    if (script->IsEmbedded()) {
+      result.push_back(V8DebuggerScript::Create(m_isolate, script, false));
       continue;
-    int contextId = static_cast<int>(contextData.As<v8::Int32>()->Value());
+    }
+    int contextId;
+    if (!script->ContextId().To(&contextId)) continue;
     if (m_inspector->contextGroupId(contextId) != contextGroupId) continue;
     result.push_back(V8DebuggerScript::Create(m_isolate, script, false));
   }

src/snapshot/startup-serializer.cc

@@ -73,6 +73,9 @@ void StartupSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code,
     Address original_address = Foreign::cast(info->getter())->foreign_address();
     Foreign::cast(info->js_getter())->set_foreign_address(original_address);
     accessor_infos_.Add(info);
+  } else if (obj->IsScript() && Script::cast(obj)->IsUserJavaScript()) {
+    Script::cast(obj)->set_context_data(
+        isolate_->heap()->uninitialized_symbol());
   }
 
   // Object has not yet been serialized.  Serialize it here.

test/inspector/debugger/step-snapshot-expected.txt

+Embedding script 'function c(f, ...args) { return f(...args); }'
+paused
+  }
+  #debugger;
+  c(f, 2);
+
+paused
+  debugger;
+  #c(f, 2);
+}
+
+paused
+function c(f, ...args) { #return f(...args); }
+
+paused
+  function f(x) {
+    #return x * 2;
+  }
+
+paused
+    return x * 2;
+  #}
+  debugger;
+
+paused
+function c(f, ...args) { return f(...args); #}
+
+paused
+  c(f, 2);
+#}
+
+paused
+test(#)

test/inspector/debugger/step-snapshot.js

+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Embed a user function in the snapshot and step through it.
+
+// Flags: --embed 'function c(f, ...args) { return f(...args); }'
+
+InspectorTest.setupScriptMap();
+
+InspectorTest.addScript(`
+function test() {
+  function f(x) {
+    return x * 2;
+  }
+  debugger;
+  c(f, 2);
+}
+//# sourceURL=test.js`);
+
+Protocol.Debugger.onPaused(message => {
+  InspectorTest.log("paused");
+  var frames = message.params.callFrames;
+  InspectorTest.logSourceLocation(frames[0].location);
+  Protocol.Debugger.stepInto();
+})
+
+Protocol.Debugger.enable()
+  .then(() => Protocol.Runtime.evaluate({ expression: 'test()' }))
+  .then(InspectorTest.completeTest);

test/inspector/inspector-test.cc

@@ -589,11 +589,22 @@ int main(int argc, char* argv[]) {
 
   v8::base::Semaphore ready_semaphore(0);
 
+  v8::StartupData startup_data = {nullptr, 0};
+  for (int i = 1; i < argc; ++i) {
+    if (strcmp(argv[i], "--embed") == 0) {
+      argv[i++] = nullptr;
+      printf("Embedding script '%s'\n", argv[i]);
+      startup_data = v8::V8::CreateSnapshotDataBlob(argv[i]);
+      argv[i] = nullptr;
+    }
+  }
+
   TaskRunner::SetupGlobalTasks backend_extensions;
   backend_extensions.emplace_back(new SetTimeoutExtension());
   backend_extensions.emplace_back(new InspectorExtension());
   TaskRunner backend_runner(std::move(backend_extensions), false,
-                            &ready_semaphore);
+                            &ready_semaphore,
+                            startup_data.data ? &startup_data : nullptr);
   ready_semaphore.Wait();
   SendMessageToBackendExtension::set_backend_task_runner(&backend_runner);
   UtilsExtension::set_backend_task_runner(&backend_runner);
@@ -602,7 +613,7 @@ int main(int argc, char* argv[]) {
   frontend_extensions.emplace_back(new UtilsExtension());
   frontend_extensions.emplace_back(new SendMessageToBackendExtension());
   TaskRunner frontend_runner(std::move(frontend_extensions), true,
-                             &ready_semaphore);
+                             &ready_semaphore, nullptr);
   ready_semaphore.Wait();
 
   FrontendChannelImpl frontend_channel(&frontend_runner);
@@ -616,7 +627,7 @@ int main(int argc, char* argv[]) {
 
   for (int i = 1; i < argc; ++i) {
     // Ignore unknown flags.
-    if (argv[i][0] == '-') continue;
+    if (argv[i] == nullptr || argv[i][0] == '-') continue;
 
     bool exists = false;
     v8::internal::Vector<const char> chars =
@@ -631,5 +642,7 @@ int main(int argc, char* argv[]) {
 
   frontend_runner.Join();
   backend_runner.Join();
+
+  delete startup_data.data;
   return 0;
 }

test/inspector/task-runner.cc

@@ -34,9 +34,11 @@ v8::internal::Vector<uint16_t> ToVector(v8::Local<v8::String> str) {
 
 TaskRunner::TaskRunner(TaskRunner::SetupGlobalTasks setup_global_tasks,
                        bool catch_exceptions,
-                       v8::base::Semaphore* ready_semaphore)
+                       v8::base::Semaphore* ready_semaphore,
+                       v8::StartupData* startup_data)
     : Thread(Options("Task Runner")),
       setup_global_tasks_(std::move(setup_global_tasks)),
+      startup_data_(startup_data),
       catch_exceptions_(catch_exceptions),
       ready_semaphore_(ready_semaphore),
       isolate_(nullptr),
@@ -51,6 +53,7 @@ void TaskRunner::InitializeIsolate() {
   v8::Isolate::CreateParams params;
   params.array_buffer_allocator =
       v8::ArrayBuffer::Allocator::NewDefaultAllocator();
+  params.snapshot_blob = startup_data_;
   isolate_ = v8::Isolate::New(params);
   isolate_->SetMicrotasksPolicy(v8::MicrotasksPolicy::kScoped);
   v8::Isolate::Scope isolate_scope(isolate_);

test/inspector/task-runner.h

@@ -45,7 +45,8 @@ class TaskRunner : public v8::base::Thread {
   using SetupGlobalTasks = std::vector<std::unique_ptr<SetupGlobalTask>>;
 
   TaskRunner(SetupGlobalTasks setup_global_tasks, bool catch_exceptions,
-             v8::base::Semaphore* ready_semaphore);
+             v8::base::Semaphore* ready_semaphore,
+             v8::StartupData* startup_data);
   virtual ~TaskRunner();
 
   // Thread implementation.
@@ -78,6 +79,7 @@ class TaskRunner : public v8::base::Thread {
   Task* GetNext(bool only_protocol);
 
   SetupGlobalTasks setup_global_tasks_;
+  v8::StartupData* startup_data_;
   bool catch_exceptions_;
   v8::base::Semaphore* ready_semaphore_;
 

test/inspector/testcfg.py

@@ -5,6 +5,7 @@
 import itertools
 import os
 import re
+import shlex
 
 from testrunner.local import testsuite
 from testrunner.local import utils
@@ -43,7 +44,7 @@ class InspectorProtocolTestSuite(testsuite.TestSuite):
     flags = [] + context.mode_flags
     flags_match = re.findall(FLAGS_PATTERN, source)
     for match in flags_match:
-      flags += match.strip().split()
+      flags += shlex.split(match.strip())
     testname = testcase.path.split(os.path.sep)[-1]
     testfilename = os.path.join(self.root, testcase.path + self.suffix())
     protocoltestfilename = os.path.join(self.root, PROTOCOL_TEST_JS)