[liveedit] fix stepping after replacing bytecode.

R=mstarzinger@chromium.org
BUG=v8:4765

Review-Url: https://codereview.chromium.org/1973213003
Cr-Commit-Position: refs/heads/master@{#36272}

src/debug/liveedit.cc

@@ -1121,6 +1121,11 @@ void LiveEdit::ReplaceFunctionCode(
       DCHECK(old_code->kind() == Code::FUNCTION);
       ReplaceCodeObject(old_code, new_code);
     }
+    if (shared_info->HasDebugInfo()) {
+      // Existing break points will be re-applied. Reset the debug info here.
+      isolate->debug()->RemoveDebugInfoAndClearFromShared(
+          handle(shared_info->GetDebugInfo()));
+    }
     Handle<Object> code_scope_info = compile_info_wrapper.GetCodeScopeInfo();
     if (code_scope_info->IsFixedArray()) {
       shared_info->set_scope_info(ScopeInfo::cast(*code_scope_info));
@@ -1820,7 +1825,8 @@ static const char* DropActivationsInActiveThreadImpl(Isolate* isolate,
   // Adjust break_frame after some frames has been dropped.
   StackFrame::Id new_id = StackFrame::NO_ID;
   for (int i = bottom_js_frame_index + 1; i < frames.length(); i++) {
-    if (frames[i]->type() == StackFrame::JAVA_SCRIPT) {
+    if (frames[i]->type() == StackFrame::JAVA_SCRIPT ||
+        frames[i]->type() == StackFrame::INTERPRETED) {
       new_id = frames[i]->id();
       break;
     }

src/runtime/runtime-debug.cc

@@ -42,6 +42,9 @@ RUNTIME_FUNCTION(Runtime_DebugBreakOnBytecode) {
   JavaScriptFrameIterator it(isolate);
   isolate->debug()->Break(it.frame());
 
+  // If live-edit has dropped frames, we are not going back to dispatch.
+  if (LiveEdit::SetAfterBreakTarget(isolate->debug())) return Smi::FromInt(0);
+
   // Return the handler from the original bytecode array.
   DCHECK(it.frame()->is_interpreted());
   InterpretedFrame* interpreted_frame =

test/mjsunit/debug-liveedit-exceptions.js

+// Copyright 2016 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.
+
+// Flags: --expose-debug-as debug
+
+Debug = debug.Debug
+
+function BestEditor() {
+  throw 'Emacs';
+}
+
+var exception = null;
+var results = [];
+var log = []
+
+function listener(event, exec_state, event_data, data) {
+  if (event != Debug.DebugEvent.Exception) return;
+  try {
+    var source_line = event_data.sourceLineText();
+    print(source_line);
+    log.push(source_line);
+    switch (results.length) {
+      case 0:
+        Replace(BestEditor, "Emacs", "Eclipse");
+        break;
+      case 1:
+        Replace(BestEditor, "Eclipse", "Vim");
+        break;
+      case 2:
+        break;
+      default:
+        assertUnreachable();
+    }
+  } catch (e) {
+    exception = e;
+  }
+};
+
+function Replace(fun, original, patch) {
+  var script = Debug.findScript(fun);
+  if (fun.toString().indexOf(original) < 0) return;
+  var patch_pos = script.source.indexOf(original);
+  var change_log = [];
+  Debug.LiveEdit.TestApi.ApplySingleChunkPatch(script, patch_pos, original.length, patch, change_log);
+}
+
+Debug.setListener(listener);
+Debug.setBreakOnException();
+
+for (var i = 0; i < 3; i++) {
+  try {
+    BestEditor();
+  } catch (e) {
+    results.push(e);
+  }
+}
+Debug.setListener(null);
+
+assertNull(exception);
+assertEquals(["Emacs", "Eclipse", "Vim"], results);
+print(JSON.stringify(log, 1));
+assertEquals([
+  "  throw 'Emacs';",
+  "  throw 'Eclipse';",
+  "  throw 'Vim';",
+], log);

test/mjsunit/debug-liveedit-stepin.js

@@ -7,8 +7,7 @@
 Debug = debug.Debug
 
 function BestEditor() {
-  var best_editor = "Emacs";
-  return best_editor;
+  return 'Emacs';
 }
 
 var exception = null;
@@ -62,20 +61,15 @@ print(JSON.stringify(log, 1));
 assertEquals([
   "debugger;",
   "results.push(BestEditor());",
-  "  var best_editor = \"Emacs\";",
-  "  return best_editor;","}",
+  "  return 'Emacs';","}",
   "results.push(BestEditor());",
   "results.push(BestEditor());",
-  "  var best_editor = \"Emacs\";",
-  "  return best_editor;",
-  "  var best_editor = \"Eclipse\";",
-  "  return best_editor;","}",
+  "  return 'Emacs';",
+  "  return 'Eclipse';","}",
   "results.push(BestEditor());",
   "results.push(BestEditor());",
-  "  var best_editor = \"Eclipse\";",
-  "  return best_editor;",
-  "  var best_editor = \"Vim\";",
-  "  return best_editor;",
+  "  return 'Eclipse';",
+  "  return 'Vim';",
   "}","results.push(BestEditor());",
   "Debug.setListener(null);"
 ], log);

test/mjsunit/mjsunit.status

@@ -287,10 +287,6 @@
   ############################################################################
   # Ignition
 
-  # TODO(rmcilroy,4765): assertion failures in LiveEdit tests.
-  'debug-liveedit-stepin': [PASS, NO_IGNITION],
-  'debug-liveedit-stack-padding': [PASS, NO_IGNITION],
-
   # TODO(mythria, 4780): Related to type feedback for calls in interpreter.
   'array-literal-feedback': [PASS, NO_IGNITION],
   'regress/regress-4121': [PASS, NO_IGNITION],
@@ -841,10 +837,6 @@
 
 ##############################################################################
 ['ignition or ignition_turbofan', {
-   # TODO(rmcilroy,4765): assertion failures in LiveEdit tests.
-  'debug-liveedit-stepin': [FAIL],
-  'debug-liveedit-stack-padding': [SKIP],
-
   # TODO(mythria, 4780): Related to type feedback for calls in interpreter.
   'array-literal-feedback': [FAIL],
   'regress/regress-4121': [FAIL],