Revert "Implement rewind: drop one or more frames from the debugger."

runtime/vm/service.cc

Index: runtime/vm/service.cc
diff --git a/runtime/vm/service.cc b/runtime/vm/service.cc
index deedaed5e3fc3d01f6b51d43cf9b2ea79e716060..5e34b4a9a4b17984245b32efc0db562261a07ba0 100644
--- a/runtime/vm/service.cc
+++ b/runtime/vm/service.cc
@@ -2988,57 +2988,18 @@ static bool GetVMTimeline(Thread* thread, JSONStream* js) {
 }
 
 
-static const char* const step_enum_names[] = {
-    "None", "Into", "Over", "Out", "Rewind", "OverAsyncSuspension", NULL,
-};
-
-
-static const Debugger::ResumeAction step_enum_values[] = {
-    Debugger::kContinue,   Debugger::kStepInto,
-    Debugger::kStepOver,   Debugger::kStepOut,
-    Debugger::kStepRewind, Debugger::kStepOverAsyncSuspension,
-    Debugger::kContinue,  // Default value
-};
-
-
 static const MethodParameter* resume_params[] = {
-    RUNNABLE_ISOLATE_PARAMETER,
-    new EnumParameter("step", false, step_enum_names),
-    new UIntParameter("frameIndex", false), NULL,
+    RUNNABLE_ISOLATE_PARAMETER, NULL,
 };
 
 
 static bool Resume(Thread* thread, JSONStream* js) {
   const char* step_param = js->LookupParam("step");
-  Debugger::ResumeAction step = Debugger::kContinue;
-  if (step_param != NULL) {
-    step = EnumMapper(step_param, step_enum_names, step_enum_values);
-  }
-#if defined(TARGET_ARCH_DBC)
-  if (step == Debugger::kStepRewind) {
-    js->PrintError(kCannotResume,
-                   "Rewind not yet implemented on this architecture");
-    return true;
-  }
-#endif
-  intptr_t frame_index = 1;
-  const char* frame_index_param = js->LookupParam("frameIndex");
-  if (frame_index_param != NULL) {
-    if (step != Debugger::kStepRewind) {
-      // Only rewind supports the frameIndex parameter.
-      js->PrintError(
-          kInvalidParams,
-          "%s: the 'frameIndex' parameter can only be used when rewinding",
-          js->method());
-      return true;
-    }
-    frame_index = UIntParameter::Parse(js->LookupParam("frameIndex"));
-  }
   Isolate* isolate = thread->isolate();
   if (isolate->message_handler()->is_paused_on_start()) {
     // If the user is issuing a 'Over' or an 'Out' step, that is the
     // same as a regular resume request.
-    if (step == Debugger::kStepInto) {
+    if ((step_param != NULL) && (strcmp(step_param, "Into") == 0)) {
       isolate->debugger()->EnterSingleStepMode();
     }
     isolate->message_handler()->set_should_pause_on_start(false);
@@ -3067,18 +3028,31 @@ static bool Resume(Thread* thread, JSONStream* js) {
     PrintSuccess(js);
     return true;
   }
-  if (isolate->debugger()->PauseEvent() == NULL) {
-    js->PrintError(kIsolateMustBePaused, NULL);
+  if (isolate->debugger()->PauseEvent() != NULL) {
+    if (step_param != NULL) {
+      if (strcmp(step_param, "Into") == 0) {
+        isolate->debugger()->SetSingleStep();
+      } else if (strcmp(step_param, "Over") == 0) {
+        isolate->debugger()->SetStepOver();
+      } else if (strcmp(step_param, "Out") == 0) {
+        isolate->debugger()->SetStepOut();
+      } else if (strcmp(step_param, "OverAsyncSuspension") == 0) {
+        if (!isolate->debugger()->SetupStepOverAsyncSuspension()) {
+          js->PrintError(kInvalidParams,
+                         "Isolate must be paused at an async suspension point");
+          return true;
+        }
+      } else {
+        PrintInvalidParamError(js, "step");
+        return true;
+      }
+    }
+    isolate->SetResumeRequest();
+    PrintSuccess(js);
     return true;
   }
 
-  const char* error = NULL;
-  if (!isolate->debugger()->SetResumeAction(step, frame_index, &error)) {
-    js->PrintError(kCannotResume, error);
-    return true;
-  }
-  isolate->SetResumeRequest();
-  PrintSuccess(js);
+  js->PrintError(kIsolateMustBePaused, NULL);
   return true;
 }