Fix array initialization with array holes

Fast mode access arrays must be converted back to normal if the array hole count reaches the limit during the initializtaion. This patch fixes jerryscript-project#3075. JerryScript-DCO-1.0-Signed-off-by: Robert Fancsik [email protected]
rerobika · Sep 6, 2019 · 735c70d · 735c70d
1 parent 57f389d
commit 735c70d
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Showing 4 changed files with 69 additions and 16 deletions.
diff --git a/jerry-core/ecma/operations/ecma-array-object.c b/jerry-core/ecma/operations/ecma-array-object.c
@@ -186,13 +186,6 @@ ecma_fast_array_convert_to_normal (ecma_object_t *object_p) /**< fast access mod
   ecma_deref_object (object_p);
 } /* ecma_fast_array_convert_to_normal */
 
-/**
- * Maximum number of array holes in a fast mode access array.
- * If the number of holes exceeds this limit, the array is converted back
- * to normal property list based array.
- */
-#define ECMA_FAST_ARRAY_MAX_HOLE_COUNT 32
-
 #if ENABLED (JERRY_SYSTEM_ALLOCATOR)
 /**
  * Maximum length of the array length to allocate fast mode access for it

diff --git a/jerry-core/ecma/operations/ecma-array-object.h b/jerry-core/ecma/operations/ecma-array-object.h
@@ -25,6 +25,13 @@
  * @{
  */
 
+/**
+ * Maximum number of array holes in a fast mode access array.
+ * If the number of holes exceeds this limit, the array is converted back
+ * to normal property list based array.
+ */
+#define ECMA_FAST_ARRAY_MAX_HOLE_COUNT 32
+
 /**
  * Flags for ecma_op_array_object_set_length
  */

diff --git a/jerry-core/vm/vm.c b/jerry-core/vm/vm.c
@@ -1668,23 +1668,58 @@ vm_loop (vm_frame_ctx_t *frame_ctx_p) /**< frame context */
           ecma_extended_object_t *ext_array_obj_p = (ecma_extended_object_t *) array_obj_p;
           uint32_t old_length = ext_array_obj_p->u.array.length;
 
-          JERRY_ASSERT (ext_array_obj_p->u.array.is_fast_mode);
+          if (JERRY_LIKELY (ext_array_obj_p->u.array.is_fast_mode))
+          {
+            ecma_value_t *values_p = ecma_fast_array_extend (array_obj_p, old_length + values_length);
 
-          ecma_value_t *values_p = ecma_fast_array_extend (array_obj_p, old_length + values_length);
+            for (uint32_t i = 0; i < values_length; i++)
+            {
+              values_p[old_length + i] = stack_top_p[i];
 
-          for (uint32_t i = 0; i < values_length; i++)
-          {
-            values_p[old_length + i] = stack_top_p[i];
+              if (JERRY_UNLIKELY (ecma_is_value_array_hole (stack_top_p[i])))
+              {
+                ext_array_obj_p->u.array.hole_count++;
+              }
+              else if (ecma_is_value_object (stack_top_p[i]))
+              {
+                ecma_deref_object (ecma_get_object_from_value (stack_top_p[i]));
+              }
+            }
 
-            if (JERRY_UNLIKELY (ecma_is_value_array_hole (stack_top_p[i])))
+            if (JERRY_UNLIKELY (ext_array_obj_p->u.array.length > ECMA_FAST_ARRAY_MAX_HOLE_COUNT))
             {
-              ext_array_obj_p->u.array.hole_count++;
+              ecma_fast_array_convert_to_normal (array_obj_p);
             }
-            else if (ecma_is_value_object (stack_top_p[i]))
+          }
+          else
+          {
+            for (uint32_t i = 0; i < values_length; i++)
             {
-              ecma_deref_object (ecma_get_object_from_value (stack_top_p[i]));
+              if (!ecma_is_value_array_hole (stack_top_p[i]))
+              {
+                ecma_string_t *index_str_p = ecma_new_ecma_string_from_uint32 (old_length + i);
+
+                ecma_property_value_t *prop_value_p;
+
+                prop_value_p = ecma_create_named_data_property (array_obj_p,
+                                                                index_str_p,
+                                                                ECMA_PROPERTY_CONFIGURABLE_ENUMERABLE_WRITABLE,
+                                                                NULL);
+
+                ecma_deref_ecma_string (index_str_p);
+                prop_value_p->value = stack_top_p[i];
+
+                if (ecma_is_value_object (stack_top_p[i]))
+                {
+                  ecma_free_value (stack_top_p[i]);
+                }
+
+              }
             }
+
+            ext_array_obj_p->u.array.length = old_length + values_length;
           }
+
           continue;
         }
         case VM_OC_PUSH_UNDEFINED_BASE:

diff --git a/tests/jerry/regression-test-issue-3072.js b/tests/jerry/regression-test-issue-3072.js
@@ -0,0 +1,18 @@
+// Copyright JS Foundation and other contributors, http://js.foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+var arr = [ , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ];
+arr [4294967294] = 0
+assert (arr.length === 4294967295);
+assert (arr[4294967294] === 0);