deps: cherry-pick 88f8fe1 from upstream V8

Original commit message: Fix collection iterator preview with deleted entries We used to assume that we know the remaining entries returned by the iterator based on the current index. However, that is not accurate, since entries skipped by the current index could be deleted. In the new approach, we allocate conservatively and shrink the result. R=neis@chromium.org Bug: v8:8433 Change-Id: I38a3004dc3af292daabb454bb76f38d65ef437e8 Reviewed-on: https://chromium-review.googlesource.com/c/1325966 Commit-Queue: Yang Guo <yangguo@chromium.org> Reviewed-by: Georg Neis <neis@chromium.org> Cr-Commit-Position: refs/heads/master@{#57360} [The backport to v10.x resolves merge conflicts due to a different way of accessing the “hole” value in V8, different signatures of the `Handle` constructor and the `Shrink()` method, and neighbouring-line conflicts in the test file.] Refs: v8/v8@88f8fe1 Fixes: #27882 Backport-PR-URL: #27894 PR-URL: #24514 Refs: #24053 Reviewed-By: Michaël Zasso <targos@protonmail.com> Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Gus Caplan <me@gus.host> Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
BethGriggs · Jul 31, 2019 · May 13, 2019 · May 2, 2019 · Nov 20, 2018 · Jun 4, 2019
commit 8f780e8f99742e4a2d3a482033de42ee3fe85637
diff --git a/common.gypi b/common.gypi
@@ -33,7 +33,7 @@
 
     # Reset this number to 0 on major V8 upgrades.
     # Increment by one for each non-official patch applied to deps/v8.
-    'v8_embedder_string': '-node.52',
+    'v8_embedder_string': '-node.53',
 
     # Enable disassembler for `--print-code` v8 options
     'v8_enable_disassembler': 1,

diff --git a/deps/v8/src/api.cc b/deps/v8/src/api.cc
@@ -7143,31 +7143,32 @@ enum class MapAsArrayKind {
 i::Handle<i::JSArray> MapAsArray(i::Isolate* isolate, i::Object* table_obj,
                                  int offset, MapAsArrayKind kind) {
   i::Factory* factory = isolate->factory();
-  i::Handle<i::OrderedHashMap> table(i::OrderedHashMap::cast(table_obj));
-  if (offset >= table->NumberOfElements()) return factory->NewJSArray(0);
-  int length = (table->NumberOfElements() - offset) *
-               (kind == MapAsArrayKind::kEntries ? 2 : 1);
-  i::Handle<i::FixedArray> result = factory->NewFixedArray(length);
+  i::Handle<i::OrderedHashMap> table(i::OrderedHashMap::cast(table_obj),
+                                     isolate);
+  const bool collect_keys =
+      kind == MapAsArrayKind::kEntries || kind == MapAsArrayKind::kKeys;
+  const bool collect_values =
+      kind == MapAsArrayKind::kEntries || kind == MapAsArrayKind::kValues;
+  int capacity = table->UsedCapacity();
+  int max_length =
+      (capacity - offset) * ((collect_keys && collect_values) ? 2 : 1);
+  i::Handle<i::FixedArray> result = factory->NewFixedArray(max_length);
   int result_index = 0;
   {
     i::DisallowHeapAllocation no_gc;
-    int capacity = table->UsedCapacity();
     i::Oddball* the_hole = isolate->heap()->the_hole_value();
-    for (int i = 0; i < capacity; ++i) {
+    for (int i = offset; i < capacity; ++i) {
       i::Object* key = table->KeyAt(i);
       if (key == the_hole) continue;
-      if (offset-- > 0) continue;
-      if (kind == MapAsArrayKind::kEntries || kind == MapAsArrayKind::kKeys) {
-        result->set(result_index++, key);
-      }
-      if (kind == MapAsArrayKind::kEntries || kind == MapAsArrayKind::kValues) {
-        result->set(result_index++, table->ValueAt(i));
-      }
+      if (collect_keys) result->set(result_index++, key);
+      if (collect_values) result->set(result_index++, table->ValueAt(i));
     }
   }
-  DCHECK_EQ(result_index, result->length());
-  DCHECK_EQ(result_index, length);
-  return factory->NewJSArrayWithElements(result, i::PACKED_ELEMENTS, length);
+  DCHECK_GE(max_length, result_index);
+  if (result_index == 0) return factory->NewJSArray(0);
+  result->Shrink(result_index);
+  return factory->NewJSArrayWithElements(result, i::PACKED_ELEMENTS,
+                                         result_index);
 }
 
 }  // namespace
@@ -7250,25 +7251,28 @@ namespace {
 i::Handle<i::JSArray> SetAsArray(i::Isolate* isolate, i::Object* table_obj,
                                  int offset) {
   i::Factory* factory = isolate->factory();
-  i::Handle<i::OrderedHashSet> table(i::OrderedHashSet::cast(table_obj));
-  int length = table->NumberOfElements() - offset;
-  if (length <= 0) return factory->NewJSArray(0);
-  i::Handle<i::FixedArray> result = factory->NewFixedArray(length);
+  i::Handle<i::OrderedHashSet> table(i::OrderedHashSet::cast(table_obj),
+                                     isolate);
+  // Elements skipped by |offset| may already be deleted.
+  int capacity = table->UsedCapacity();
+  int max_length = capacity - offset;
+  if (max_length == 0) return factory->NewJSArray(0);
+  i::Handle<i::FixedArray> result = factory->NewFixedArray(max_length);
   int result_index = 0;
   {
     i::DisallowHeapAllocation no_gc;
-    int capacity = table->UsedCapacity();
     i::Oddball* the_hole = isolate->heap()->the_hole_value();
-    for (int i = 0; i < capacity; ++i) {
+    for (int i = offset; i < capacity; ++i) {
       i::Object* key = table->KeyAt(i);
       if (key == the_hole) continue;
-      if (offset-- > 0) continue;
       result->set(result_index++, key);
     }
   }
-  DCHECK_EQ(result_index, result->length());
-  DCHECK_EQ(result_index, length);
-  return factory->NewJSArrayWithElements(result, i::PACKED_ELEMENTS, length);
+  DCHECK_GE(max_length, result_index);
+  if (result_index == 0) return factory->NewJSArray(0);
+  result->Shrink(result_index);
+  return factory->NewJSArrayWithElements(result, i::PACKED_ELEMENTS,
+                                         result_index);
 }
 }  // namespace
 

diff --git a/deps/v8/test/cctest/test-api.cc b/deps/v8/test/cctest/test-api.cc
@@ -28066,3 +28066,217 @@ TEST(BigIntAPI) {
     CHECK_EQ(word_count, 2);
   }
 }
+
+TEST(PreviewSetIteratorEntriesWithDeleted) {
+  LocalContext env;
+  v8::HandleScope handle_scope(env->GetIsolate());
+  v8::Local<v8::Context> context = env.local();
+
+  {
+    // Create set, delete entry, create iterator, preview.
+    v8::Local<v8::Object> iterator =
+        CompileRun("var set = new Set([1,2,3]); set.delete(1); set.keys()")
+            ->ToObject(context)
+            .ToLocalChecked();
+    bool is_key;
+    v8::Local<v8::Array> entries =
+        iterator->PreviewEntries(&is_key).ToLocalChecked();
+    CHECK(!is_key);
+    CHECK_EQ(2, entries->Length());
+    CHECK_EQ(2, entries->Get(context, 0)
+                    .ToLocalChecked()
+                    ->Int32Value(context)
+                    .FromJust());
+    CHECK_EQ(3, entries->Get(context, 1)
+                    .ToLocalChecked()
+                    ->Int32Value(context)
+                    .FromJust());
+  }
+  {
+    // Create set, create iterator, delete entry, preview.
+    v8::Local<v8::Object> iterator =
+        CompileRun("var set = new Set([1,2,3]); set.keys()")
+            ->ToObject(context)
+            .ToLocalChecked();
+    CompileRun("set.delete(1);");
+    bool is_key;
+    v8::Local<v8::Array> entries =
+        iterator->PreviewEntries(&is_key).ToLocalChecked();
+    CHECK(!is_key);
+    CHECK_EQ(2, entries->Length());
+    CHECK_EQ(2, entries->Get(context, 0)
+                    .ToLocalChecked()
+                    ->Int32Value(context)
+                    .FromJust());
+    CHECK_EQ(3, entries->Get(context, 1)
+                    .ToLocalChecked()
+                    ->Int32Value(context)
+                    .FromJust());
+  }
+  {
+    // Create set, create iterator, delete entry, iterate, preview.
+    v8::Local<v8::Object> iterator =
+        CompileRun("var set = new Set([1,2,3]); var it = set.keys(); it")
+            ->ToObject(context)
+            .ToLocalChecked();
+    CompileRun("set.delete(1); it.next();");
+    bool is_key;
+    v8::Local<v8::Array> entries =
+        iterator->PreviewEntries(&is_key).ToLocalChecked();
+    CHECK(!is_key);
+    CHECK_EQ(1, entries->Length());
+    CHECK_EQ(3, entries->Get(context, 0)
+                    .ToLocalChecked()
+                    ->Int32Value(context)
+                    .FromJust());
+  }
+  {
+    // Create set, create iterator, delete entry, iterate until empty, preview.
+    v8::Local<v8::Object> iterator =
+        CompileRun("var set = new Set([1,2,3]); var it = set.keys(); it")
+            ->ToObject(context)
+            .ToLocalChecked();
+    CompileRun("set.delete(1); it.next(); it.next();");
+    bool is_key;
+    v8::Local<v8::Array> entries =
+        iterator->PreviewEntries(&is_key).ToLocalChecked();
+    CHECK(!is_key);
+    CHECK_EQ(0, entries->Length());
+  }
+  {
+    // Create set, create iterator, delete entry, iterate, trigger rehash,
+    // preview.
+    v8::Local<v8::Object> iterator =
+        CompileRun("var set = new Set([1,2,3]); var it = set.keys(); it")
+            ->ToObject(context)
+            .ToLocalChecked();
+    CompileRun("set.delete(1); it.next();");
+    CompileRun("for (var i = 4; i < 20; i++) set.add(i);");
+    bool is_key;
+    v8::Local<v8::Array> entries =
+        iterator->PreviewEntries(&is_key).ToLocalChecked();
+    CHECK(!is_key);
+    CHECK_EQ(17, entries->Length());
+    for (uint32_t i = 0; i < 17; i++) {
+      CHECK_EQ(i + 3, entries->Get(context, i)
+                          .ToLocalChecked()
+                          ->Int32Value(context)
+                          .FromJust());
+    }
+  }
+}
+
+TEST(PreviewMapIteratorEntriesWithDeleted) {
+  LocalContext env;
+  v8::HandleScope handle_scope(env->GetIsolate());
+  v8::Local<v8::Context> context = env.local();
+
+  {
+    // Create map, delete entry, create iterator, preview.
+    v8::Local<v8::Object> iterator = CompileRun(
+                                         "var map = new Map();"
+                                         "var key = {}; map.set(key, 1);"
+                                         "map.set({}, 2); map.set({}, 3);"
+                                         "map.delete(key);"
+                                         "map.values()")
+                                         ->ToObject(context)
+                                         .ToLocalChecked();
+    bool is_key;
+    v8::Local<v8::Array> entries =
+        iterator->PreviewEntries(&is_key).ToLocalChecked();
+    CHECK(!is_key);
+    CHECK_EQ(2, entries->Length());
+    CHECK_EQ(2, entries->Get(context, 0)
+                    .ToLocalChecked()
+                    ->Int32Value(context)
+                    .FromJust());
+    CHECK_EQ(3, entries->Get(context, 1)
+                    .ToLocalChecked()
+                    ->Int32Value(context)
+                    .FromJust());
+  }
+  {
+    // Create map, create iterator, delete entry, preview.
+    v8::Local<v8::Object> iterator = CompileRun(
+                                         "var map = new Map();"
+                                         "var key = {}; map.set(key, 1);"
+                                         "map.set({}, 2); map.set({}, 3);"
+                                         "map.values()")
+                                         ->ToObject(context)
+                                         .ToLocalChecked();
+    CompileRun("map.delete(key);");
+    bool is_key;
+    v8::Local<v8::Array> entries =
+        iterator->PreviewEntries(&is_key).ToLocalChecked();
+    CHECK(!is_key);
+    CHECK_EQ(2, entries->Length());
+    CHECK_EQ(2, entries->Get(context, 0)
+                    .ToLocalChecked()
+                    ->Int32Value(context)
+                    .FromJust());
+    CHECK_EQ(3, entries->Get(context, 1)
+                    .ToLocalChecked()
+                    ->Int32Value(context)
+                    .FromJust());
+  }
+  {
+    // Create map, create iterator, delete entry, iterate, preview.
+    v8::Local<v8::Object> iterator = CompileRun(
+                                         "var map = new Map();"
+                                         "var key = {}; map.set(key, 1);"
+                                         "map.set({}, 2); map.set({}, 3);"
+                                         "var it = map.values(); it")
+                                         ->ToObject(context)
+                                         .ToLocalChecked();
+    CompileRun("map.delete(key); it.next();");
+    bool is_key;
+    v8::Local<v8::Array> entries =
+        iterator->PreviewEntries(&is_key).ToLocalChecked();
+    CHECK(!is_key);
+    CHECK_EQ(1, entries->Length());
+    CHECK_EQ(3, entries->Get(context, 0)
+                    .ToLocalChecked()
+                    ->Int32Value(context)
+                    .FromJust());
+  }
+  {
+    // Create map, create iterator, delete entry, iterate until empty, preview.
+    v8::Local<v8::Object> iterator = CompileRun(
+                                         "var map = new Map();"
+                                         "var key = {}; map.set(key, 1);"
+                                         "map.set({}, 2); map.set({}, 3);"
+                                         "var it = map.values(); it")
+                                         ->ToObject(context)
+                                         .ToLocalChecked();
+    CompileRun("map.delete(key); it.next(); it.next();");
+    bool is_key;
+    v8::Local<v8::Array> entries =
+        iterator->PreviewEntries(&is_key).ToLocalChecked();
+    CHECK(!is_key);
+    CHECK_EQ(0, entries->Length());
+  }
+  {
+    // Create map, create iterator, delete entry, iterate, trigger rehash,
+    // preview.
+    v8::Local<v8::Object> iterator = CompileRun(
+                                         "var map = new Map();"
+                                         "var key = {}; map.set(key, 1);"
+                                         "map.set({}, 2); map.set({}, 3);"
+                                         "var it = map.values(); it")
+                                         ->ToObject(context)
+                                         .ToLocalChecked();
+    CompileRun("map.delete(key); it.next();");
+    CompileRun("for (var i = 4; i < 20; i++) map.set({}, i);");
+    bool is_key;
+    v8::Local<v8::Array> entries =
+        iterator->PreviewEntries(&is_key).ToLocalChecked();
+    CHECK(!is_key);
+    CHECK_EQ(17, entries->Length());
+    for (uint32_t i = 0; i < 17; i++) {
+      CHECK_EQ(i + 3, entries->Get(context, i)
+                          .ToLocalChecked()
+                          ->Int32Value(context)
+                          .FromJust());
+    }
+  }
+}