Start adding vm/cc tests for rewind functionality.

runtime/vm/debugger_test.cc

Index: runtime/vm/debugger_test.cc
diff --git a/runtime/vm/debugger_test.cc b/runtime/vm/debugger_test.cc
index 6096965985244452b1ae141daa5e00e3a1905068..a783ce69ca48faac23155825628626b9d36a5404 100644
--- a/runtime/vm/debugger_test.cc
+++ b/runtime/vm/debugger_test.cc
@@ -3,7 +3,9 @@
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/dart_api_impl.h"
+#include "vm/dart_api_message.h"
 #include "vm/debugger.h"
+#include "vm/message.h"
 #include "vm/unit_test.h"
 
 namespace dart {
@@ -11,6 +13,7 @@ namespace dart {
 #ifndef PRODUCT
 
 DECLARE_FLAG(bool, remove_script_timestamps_for_test);
+DECLARE_FLAG(bool, trace_rewind);
 
 // Search for the formatted string in buffer.
 //
@@ -141,6 +144,204 @@ TEST_CASE(Debugger_PauseEvent) {
   EXPECT(saw_paused_event);
 }
 
+
+static uint8_t* malloc_allocator(uint8_t* ptr,
+                                 intptr_t old_size,
+                                 intptr_t new_size) {
+  void* new_ptr = realloc(reinterpret_cast<void*>(ptr), new_size);
+  return reinterpret_cast<uint8_t*>(new_ptr);
+}
+
+
+const char* rewind_frame_index = "-1";
+
+
+// Build and send a fake resume OOB message for testing purposes.
+void SendResumeMessage(Isolate* isolate) {
+  // Format is: [ oob_type, port, seq, method_name, [keys], [values] ]
+  Dart_CObject msg;
+  Dart_CObject* list_values[6];
+  msg.type = Dart_CObject_kArray;
+  msg.value.as_array.length = 6;
+  msg.value.as_array.values = list_values;
+
+  Dart_CObject oob;
+  oob.type = Dart_CObject_kInt32;
+  oob.value.as_int32 = Message::kServiceOOBMsg;
+  list_values[0] = &oob;
+
+  Dart_CObject reply_port;
+  reply_port.type = Dart_CObject_kNull;
+  list_values[1] = &reply_port;
+
+  Dart_CObject seq;
+  seq.type = Dart_CObject_kNull;
+  list_values[2] = &seq;
+
+  Dart_CObject method_name;
+  method_name.type = Dart_CObject_kString;
+  method_name.value.as_string = const_cast<char*>("resume");
+  list_values[3] = &method_name;
+
+  const int kParamCount = 3;
+  Dart_CObject param_keys;
+  Dart_CObject* param_keys_list[kParamCount];
+  param_keys.type = Dart_CObject_kArray;
+  param_keys.value.as_array.values = param_keys_list;
+  param_keys.value.as_array.length = kParamCount;
+  list_values[4] = &param_keys;
+
+  Dart_CObject param_values;
+  Dart_CObject* param_values_list[kParamCount];
+  param_values.type = Dart_CObject_kArray;
+  param_values.value.as_array.values = param_values_list;
+  param_values.value.as_array.length = kParamCount;
+  list_values[5] = &param_values;
+
+  Dart_CObject param0_name;
+  param0_name.type = Dart_CObject_kString;
+  param0_name.value.as_string = const_cast<char*>("isolateId");
+  param_keys_list[0] = &param0_name;
+
+  Dart_CObject param0_value;
+  param0_value.type = Dart_CObject_kString;
+  const char* isolate_id = Thread::Current()->zone()->PrintToString(
+      ISOLATE_SERVICE_ID_FORMAT_STRING,
+      static_cast<int64_t>(isolate->main_port()));
+  param0_value.value.as_string = const_cast<char*>(isolate_id);
+  param_values_list[0] = &param0_value;
+
+  Dart_CObject param1_name;
+  param1_name.type = Dart_CObject_kString;
+  param1_name.value.as_string = const_cast<char*>("step");
+  param_keys_list[1] = &param1_name;
+
+  Dart_CObject param1_value;
+  param1_value.type = Dart_CObject_kString;
+  param1_value.value.as_string = const_cast<char*>("Rewind");
+  param_values_list[1] = &param1_value;
+
+  Dart_CObject param2_name;
+  param2_name.type = Dart_CObject_kString;
+  param2_name.value.as_string = const_cast<char*>("frameIndex");
+  param_keys_list[2] = &param2_name;
+
+  Dart_CObject param2_value;
+  param2_value.type = Dart_CObject_kString;
+  param2_value.value.as_string = const_cast<char*>(rewind_frame_index);
+  param_values_list[2] = &param2_value;
+
+  {
+    uint8_t* buffer = NULL;
+    ApiMessageWriter writer(&buffer, &malloc_allocator);
+    bool success = writer.WriteCMessage(&msg);
+    ASSERT(success);
+
+    // Post the message at the given port.
+    success = PortMap::PostMessage(new Message(isolate->main_port(), buffer,
+                                               writer.BytesWritten(),
+                                               Message::kOOBPriority));
+    ASSERT(success);
+  }
+}
+
+
+static void RewindOnce(Dart_IsolateId isolate_id,
+                       intptr_t bp_id,
+                       const Dart_CodeLocation& loc) {
+  bool first_time = !saw_paused_event;
+  saw_paused_event = true;
+  if (first_time) {
+    Thread* T = Thread::Current();
+    Isolate* I = T->isolate();
+    I->set_is_runnable(true);

[rmacnak, 2017/01/31 19:21:00]

Weird.

[turnidge, 2017/01/31 19:35:46]

Added a TODO

+    SendResumeMessage(I);
+    I->PauseEventHandler();
+  }
+}
+
+
+TEST_CASE(Debugger_RewindOneFrame_Unoptimized) {
+  SetFlagScope<bool> sfs(&FLAG_trace_rewind, true);
+  saw_paused_event = false;
+  rewind_frame_index = "1";
+
+  const char* kScriptChars =
+      "import 'dart:developer';\n"
+      "\n"
+      "var msg = new StringBuffer();\n"
+      "\n"
+      "foo() {\n"
+      "  msg.write('enter(foo) ');\n"
+      "  debugger();\n"
+      "  msg.write('exit(foo) ');\n"
+      "}\n"
+      "\n"
+      "main() {\n"
+      "  msg.write('enter(main) ');\n"
+      "  foo();\n"
+      "  msg.write('exit(main) ');\n"
+      "  return msg.toString();\n"
+      "}\n";
+  Dart_Handle lib = TestCase::LoadTestScript(kScriptChars, NULL);
+  EXPECT_VALID(lib);
+
+  Dart_SetPausedEventHandler(RewindOnce);
+  Dart_Handle result = Dart_Invoke(lib, NewString("main"), 0, NULL);
+  const char* result_cstr;
+  EXPECT_VALID(result);
+  EXPECT(Dart_IsString(result));
+  EXPECT_VALID(Dart_StringToCString(result, &result_cstr));
+  EXPECT_STREQ("enter(main) enter(foo) enter(foo) exit(foo) exit(main) ",
+               result_cstr);
+  EXPECT(saw_paused_event);
+}
+
+
+TEST_CASE(Debugger_RewindTwoFrames_Unoptimized) {
+  SetFlagScope<bool> sfs(&FLAG_trace_rewind, true);
+  saw_paused_event = false;
+  rewind_frame_index = "2";
+
+  const char* kScriptChars =
+      "import 'dart:developer';\n"
+      "\n"
+      "var msg = new StringBuffer();\n"
+      "\n"
+      "foo() {\n"
+      "  msg.write('enter(foo) ');\n"
+      "  debugger();\n"
+      "  msg.write('exit(foo) ');\n"
+      "}\n"
+      "\n"
+      "bar() {\n"
+      "  msg.write('enter(bar) ');\n"
+      "  foo();\n"
+      "  msg.write('exit(bar) ');\n"
+      "}\n"
+      "\n"
+      "main() {\n"
+      "  msg.write('enter(main) ');\n"
+      "  bar();\n"
+      "  msg.write('exit(main) ');\n"
+      "  return msg.toString();\n"
+      "}\n";
+  Dart_Handle lib = TestCase::LoadTestScript(kScriptChars, NULL);
+  EXPECT_VALID(lib);
+
+  Dart_SetPausedEventHandler(RewindOnce);
+  Dart_Handle result = Dart_Invoke(lib, NewString("main"), 0, NULL);
+  const char* result_cstr;
+  EXPECT_VALID(result);
+  EXPECT(Dart_IsString(result));
+  EXPECT_VALID(Dart_StringToCString(result, &result_cstr));
+  EXPECT_STREQ(
+      "enter(main) enter(bar) enter(foo) enter(bar) enter(foo) "
+      "exit(foo) exit(bar) exit(main) ",
+      result_cstr);
+  EXPECT(saw_paused_event);
+}
+
 #endif  // !PRODUCT
 
 }  // namespace dart