Revert "Prevent liveedit on or under generators with open activations"

Seems to crash some tests on buildbots.

TBR=ishell@chromium.org
CC=wingo@igalia.com,yangguo@chromium.org
BUG=

Review URL: https://codereview.chromium.org/273433002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21178 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/liveedit-debugger.js

@@ -946,9 +946,7 @@ Debug.LiveEdit = new function() {
       BLOCKED_ON_ACTIVE_STACK: 2,
       BLOCKED_ON_OTHER_STACK: 3,
       BLOCKED_UNDER_NATIVE_CODE: 4,
-      REPLACED_ON_ACTIVE_STACK: 5,
-      BLOCKED_UNDER_GENERATOR: 6,
-      BLOCKED_ACTIVE_GENERATOR: 7
+      REPLACED_ON_ACTIVE_STACK: 5
   };
 
   FunctionPatchabilityStatus.SymbolName = function(code) {

src/liveedit.cc

@@ -1682,6 +1682,11 @@ static const char* DropFrames(Vector<StackFrame*> frames,
 }
 
 
+static bool IsDropableFrame(StackFrame* frame) {
+  return !frame->is_exit();
+}
+
+
 // Describes a set of call frames that execute any of listed functions.
 // Finding no such frames does not mean error.
 class MultipleFunctionTarget {
@@ -1735,20 +1740,12 @@ static const char* DropActivationsInActiveThreadImpl(
 
   bool target_frame_found = false;
   int bottom_js_frame_index = top_frame_index;
-  bool non_droppable_frame_found = false;
-  LiveEdit::FunctionPatchabilityStatus non_droppable_reason;
+  bool c_code_found = false;
 
   for (; frame_index < frames.length(); frame_index++) {
     StackFrame* frame = frames[frame_index];
-    if (frame->is_exit()) {
-      non_droppable_frame_found = true;
-      non_droppable_reason = LiveEdit::FUNCTION_BLOCKED_UNDER_NATIVE_CODE;
-      break;
-    }
-    if (!frame->is_java_script()) continue;
-    if (JavaScriptFrame::cast(frame)->function()->shared()->is_generator()) {
-      non_droppable_frame_found = true;
-      non_droppable_reason = LiveEdit::FUNCTION_BLOCKED_UNDER_GENERATOR;
+    if (!IsDropableFrame(frame)) {
+      c_code_found = true;
       break;
     }
     if (target.MatchActivation(
@@ -1758,15 +1755,15 @@ static const char* DropActivationsInActiveThreadImpl(
     }
   }
 
-  if (non_droppable_frame_found) {
-    // There is a C or generator frame on stack.  We can't drop C frames, and we
-    // can't restart generators.  Check that there are no target frames below
-    // them.
+  if (c_code_found) {
+    // There is a C frames on stack. Check that there are no target frames
+    // below them.
     for (; frame_index < frames.length(); frame_index++) {
       StackFrame* frame = frames[frame_index];
       if (frame->is_java_script()) {
-        if (target.MatchActivation(frame, non_droppable_reason)) {
-          // Fail.
+        if (target.MatchActivation(
+                frame, LiveEdit::FUNCTION_BLOCKED_UNDER_NATIVE_CODE)) {
+          // Cannot drop frame under C frames.
           return NULL;
         }
       }
@@ -1836,47 +1833,6 @@ static const char* DropActivationsInActiveThread(
 }
 
 
-bool LiveEdit::FindActiveGenerators(Handle<FixedArray> shared_info_array,
-                                    Handle<FixedArray> result,
-                                    int len) {
-  Isolate* isolate = shared_info_array->GetIsolate();
-  Heap* heap = isolate->heap();
-  heap->EnsureHeapIsIterable();
-  bool found_suspended_activations = false;
-
-  ASSERT_LE(len, result->length());
-
-  DisallowHeapAllocation no_allocation;
-
-  FunctionPatchabilityStatus active = FUNCTION_BLOCKED_ACTIVE_GENERATOR;
-
-  HeapIterator iterator(heap);
-  HeapObject* obj = NULL;
-  while ((obj = iterator.next()) != NULL) {
-    if (!obj->IsJSGeneratorObject()) continue;
-
-    JSGeneratorObject* gen = JSGeneratorObject::cast(obj);
-    if (gen->is_closed()) continue;
-
-    HandleScope scope(isolate);
-
-    for (int i = 0; i < len; i++) {
-      Handle<JSValue> jsvalue =
-          Handle<JSValue>::cast(FixedArray::get(shared_info_array, i));
-      Handle<SharedFunctionInfo> shared =
-          UnwrapSharedFunctionInfoFromJSValue(jsvalue);
-
-      if (gen->function()->shared() == *shared) {
-        result->set(i, Smi::FromInt(active));
-        found_suspended_activations = true;
-      }
-    }
-  }
-
-  return found_suspended_activations;
-}
-
-
 class InactiveThreadActivationsChecker : public ThreadVisitor {
  public:
   InactiveThreadActivationsChecker(Handle<JSArray> shared_info_array,
@@ -1907,29 +1863,18 @@ Handle<JSArray> LiveEdit::CheckAndDropActivations(
   Isolate* isolate = shared_info_array->GetIsolate();
   int len = GetArrayLength(shared_info_array);
 
-  CHECK(shared_info_array->HasFastElements());
-  Handle<FixedArray> shared_info_array_elements(
-      FixedArray::cast(shared_info_array->elements()));
-
   Handle<JSArray> result = isolate->factory()->NewJSArray(len);
-  Handle<FixedArray> result_elements =
-      JSObject::EnsureWritableFastElements(result);
 
   // Fill the default values.
   for (int i = 0; i < len; i++) {
-    FunctionPatchabilityStatus status = FUNCTION_AVAILABLE_FOR_PATCH;
-    result_elements->set(i, Smi::FromInt(status));
+    SetElementSloppy(
+        result,
+        i,
+        Handle<Smi>(Smi::FromInt(FUNCTION_AVAILABLE_FOR_PATCH), isolate));
   }
 
-  // Scan the heap for active generators -- those that are either currently
-  // running (as we wouldn't want to restart them, because we don't know where
-  // to restart them from) or suspended.  Fail if any one corresponds to the set
-  // of functions being edited.
-  if (FindActiveGenerators(shared_info_array_elements, result_elements, len)) {
-    return result;
-  }
 
-  // Check inactive threads. Fail if some functions are blocked there.
+  // First check inactive threads. Fail if some functions are blocked there.
   InactiveThreadActivationsChecker inactive_threads_checker(shared_info_array,
                                                             result);
   isolate->thread_manager()->IterateArchivedThreads(
@@ -1992,9 +1937,6 @@ const char* LiveEdit::RestartFrame(JavaScriptFrame* frame) {
   if (target.saved_status() == LiveEdit::FUNCTION_BLOCKED_UNDER_NATIVE_CODE) {
     return "Function is blocked under native code";
   }
-  if (target.saved_status() == LiveEdit::FUNCTION_BLOCKED_UNDER_GENERATOR) {
-    return "Function is blocked under a generator activation";
-  }
   return NULL;
 }
 

src/liveedit.h

@@ -89,11 +89,6 @@ class LiveEdit : AllStatic {
                                          Handle<JSValue> orig_function_shared,
                                          Handle<JSValue> subst_function_shared);
 
-  // Find open generator activations, and set corresponding "result" elements to
-  // FUNCTION_BLOCKED_ACTIVE_GENERATOR.
-  static bool FindActiveGenerators(Handle<FixedArray> shared_info_array,
-                                   Handle<FixedArray> result, int len);
-
   // Checks listed functions on stack and return array with corresponding
   // FunctionPatchabilityStatus statuses; extra array element may
   // contain general error message. Modifies the current stack and
@@ -112,9 +107,7 @@ class LiveEdit : AllStatic {
     FUNCTION_BLOCKED_ON_ACTIVE_STACK = 2,
     FUNCTION_BLOCKED_ON_OTHER_STACK = 3,
     FUNCTION_BLOCKED_UNDER_NATIVE_CODE = 4,
-    FUNCTION_REPLACED_ON_ACTIVE_STACK = 5,
-    FUNCTION_BLOCKED_UNDER_GENERATOR = 6,
-    FUNCTION_BLOCKED_ACTIVE_GENERATOR = 7
+    FUNCTION_REPLACED_ON_ACTIVE_STACK = 5
   };
 
   // Compares 2 strings line-by-line, then token-wise and returns diff in form

src/objects-inl.h

@@ -5718,14 +5718,6 @@ bool JSGeneratorObject::is_suspended() {
   return continuation() > 0;
 }
 
-bool JSGeneratorObject::is_closed() {
-  return continuation() == kGeneratorClosed;
-}
-
-bool JSGeneratorObject::is_executing() {
-  return continuation() == kGeneratorExecuting;
-}
-
 JSGeneratorObject* JSGeneratorObject::cast(Object* obj) {
   ASSERT(obj->IsJSGeneratorObject());
   ASSERT(HeapObject::cast(obj)->Size() == JSGeneratorObject::kSize);

src/objects.h

@@ -7460,8 +7460,6 @@ class JSGeneratorObject: public JSObject {
   // cannot be resumed.
   inline int continuation();
   inline void set_continuation(int continuation);
-  inline bool is_closed();
-  inline bool is_executing();
   inline bool is_suspended();
 
   // [operand_stack]: Saved operand stack.

test/mjsunit/harmony/generators-debug-liveedit.js

-// Copyright 2014 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 --harmony-generators
-
-var Debug = debug.Debug;
-var LiveEdit = Debug.LiveEdit;
-
-unique_id = 0;
-
-var Generator = (function*(){}).constructor;
-
-function assertIteratorResult(value, done, result) {
-  assertEquals({value: value, done: done}, result);
-}
-
-function MakeGenerator() {
-  // Prevents eval script caching.
-  unique_id++;
-  return Generator('callback',
-      "/* " + unique_id + "*/\n" +
-      "yield callback();\n" +
-      "return 'Cat';\n");
-}
-
-function MakeFunction() {
-  // Prevents eval script caching.
-  unique_id++;
-  return Function('callback',
-      "/* " + unique_id + "*/\n" +
-      "callback();\n" +
-      "return 'Cat';\n");
-}
-
-// First, try MakeGenerator with no perturbations.
-(function(){
-  var generator = MakeGenerator();
-  function callback() {};
-  var iter = generator(callback);
-  assertIteratorResult(undefined, false, iter.next());
-  assertIteratorResult("Cat", true, iter.next());
-})();
-
-function patch(fun, from, to) {
-  function debug() {
-    var log = new Array();
-    var script = Debug.findScript(fun);
-    var pos = script.source.indexOf(from);
-    try {
-      LiveEdit.TestApi.ApplySingleChunkPatch(script, pos, from.length, to,
-                                             log);
-    } finally {
-      print("Change log: " + JSON.stringify(log) + "\n");
-    }
-  }
-  Debug.ExecuteInDebugContext(debug, false);
-}
-
-// Try to edit a MakeGenerator while it's running, then again while it's
-// stopped.
-(function(){
-  var generator = MakeGenerator();
-
-  var gen_patch_attempted = false;
-  function attempt_gen_patch() {
-    assertFalse(gen_patch_attempted);
-    gen_patch_attempted = true;
-    assertThrows(function() { patch(generator, "'Cat'", "'Capybara'") },
-                 LiveEdit.Failure);
-  };
-  var iter = generator(attempt_gen_patch);
-  assertIteratorResult(undefined, false, iter.next());
-  // Patch should not succeed because there is a live generator activation on
-  // the stack.
-  assertIteratorResult("Cat", true, iter.next());
-  assertTrue(gen_patch_attempted);
-
-  // At this point one iterator is live, but closed, so the patch will succeed.
-  patch(generator, "'Cat'", "'Capybara'");
-  iter = generator(function(){});
-  assertIteratorResult(undefined, false, iter.next());
-  // Patch successful.
-  assertIteratorResult("Capybara", true, iter.next());
-
-  // Patching will fail however when a live iterator is suspended.
-  iter = generator(function(){});
-  assertIteratorResult(undefined, false, iter.next());
-  assertThrows(function() { patch(generator, "'Capybara'", "'Tapir'") },
-               LiveEdit.Failure);
-  assertIteratorResult("Capybara", true, iter.next());
-
-  // Try to patch functions with activations inside and outside generator
-  // function activations.  We should succeed in the former case, but not in the
-  // latter.
-  var fun_outside = MakeFunction();
-  var fun_inside = MakeFunction();
-  var fun_patch_attempted = false;
-  var fun_patch_restarted = false;
-  function attempt_fun_patches() {
-    if (fun_patch_attempted) {
-      assertFalse(fun_patch_restarted);
-      fun_patch_restarted = true;
-      return;
-    }
-    fun_patch_attempted = true;
-    // Patching outside a generator activation must fail.
-    assertThrows(function() { patch(fun_outside, "'Cat'", "'Cobra'") },
-                 LiveEdit.Failure);
-    // Patching inside a generator activation may succeed.
-    patch(fun_inside, "'Cat'", "'Koala'");
-  }
-  iter = generator(function() { return fun_inside(attempt_fun_patches) });
-  assertEquals('Cat',
-               fun_outside(function () {
-                 assertIteratorResult('Koala', false, iter.next());
-                 assertTrue(fun_patch_restarted);
-               }));
-})();

test/mjsunit/mjsunit.status

@@ -183,7 +183,6 @@
   'debug-liveedit-stack-padding': [SKIP],
   'debug-liveedit-restart-frame': [SKIP],
   'debug-liveedit-double-call': [SKIP],
-  'harmony/generators-debug-liveedit': [SKIP],
 
   # BUG(v8:3147). It works on other architectures by accident.
   'regress/regress-conditional-position': [FAIL],
@@ -280,7 +279,6 @@
   'debug-liveedit-stack-padding': [SKIP],
   'debug-liveedit-restart-frame': [SKIP],
   'debug-liveedit-double-call': [SKIP],
-  'harmony/generators-debug-liveedit': [SKIP],
 
   # Currently always deopt on minus zero
   'math-floor-of-div-minus-zero': [SKIP],
@@ -332,7 +330,6 @@
   'debug-liveedit-stack-padding': [SKIP],
   'debug-liveedit-restart-frame': [SKIP],
   'debug-liveedit-double-call': [SKIP],
-  'harmony/generators-debug-liveedit': [SKIP],
 
   # Currently always deopt on minus zero
   'math-floor-of-div-minus-zero': [SKIP],
@@ -353,7 +350,6 @@
   'debug-liveedit-stack-padding': [SKIP],
   'debug-liveedit-restart-frame': [SKIP],
   'debug-liveedit-double-call': [SKIP],
-  'harmony/generators-debug-liveedit': [SKIP],
 
   # This test dumps core for arm.debug, so no reason to expect it to work
   # for NaCl. The other three fuzz-natives tests seem to run fine.