From 79bc5d02208935bad827e5c2a42a0fd2d2ef6e9e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Istv=C3=A1n=20K=C3=A1d=C3=A1r?= <ikadar@inf.u-szeged.hu>
Date: Wed, 27 Jul 2016 16:35:25 +0200
Subject: [PATCH] Bugfixes related to low memory conditions.
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 - Bugfix for removing property hashmap in ecma_gc_run.
 - Fixed bug in ecma_create_property() caused by the new property pair allocation.

JerryScript-DCO-1.0-Signed-off-by: István Kádár ikadar@inf.u-szeged.hu
---
 jerry-core/ecma/base/ecma-gc.c      | 13 ++++++----
 jerry-core/ecma/base/ecma-helpers.c | 40 +++++++++++++++++++----------
 2 files changed, 34 insertions(+), 19 deletions(-)

diff --git a/jerry-core/ecma/base/ecma-gc.c b/jerry-core/ecma/base/ecma-gc.c
index 8731b02a6..707a4ed47 100644
--- a/jerry-core/ecma/base/ecma-gc.c
+++ b/jerry-core/ecma/base/ecma-gc.c
@@ -549,12 +549,15 @@ ecma_gc_run (jmem_free_unused_memory_severity_t severity) /**< gc severity */
     {
       JERRY_ASSERT (ecma_gc_is_object_visited (obj_iter_p));
 
-      ecma_property_header_t *prop_iter_p = ecma_get_property_list (obj_iter_p);
-
-      if (prop_iter_p != NULL
-          && ECMA_PROPERTY_GET_TYPE (prop_iter_p->types + 0) == ECMA_PROPERTY_TYPE_HASHMAP)
+      if (!ecma_is_lexical_environment (obj_iter_p)
+          || ecma_get_lex_env_type (obj_iter_p) == ECMA_LEXICAL_ENVIRONMENT_DECLARATIVE)
       {
-        ecma_property_hashmap_free (obj_iter_p);
+        ecma_property_header_t *prop_iter_p = ecma_get_property_list (obj_iter_p);
+        if (prop_iter_p != NULL
+            && ECMA_PROPERTY_GET_TYPE (prop_iter_p->types + 0) == ECMA_PROPERTY_TYPE_HASHMAP)
+        {
+          ecma_property_hashmap_free (obj_iter_p);
+        }
       }
 
       obj_iter_p = ecma_gc_get_object_next (obj_iter_p);
diff --git a/jerry-core/ecma/base/ecma-helpers.c b/jerry-core/ecma/base/ecma-helpers.c
index f38072c3e..948d6aaf7 100644
--- a/jerry-core/ecma/base/ecma-helpers.c
+++ b/jerry-core/ecma/base/ecma-helpers.c
@@ -401,26 +401,21 @@ ecma_create_property (ecma_object_t *object_p, /**< the object */
   JERRY_ASSERT (ECMA_PROPERTY_PAIR_ITEM_COUNT == 2);
 
   jmem_cpointer_t *property_list_head_p = &object_p->property_list_or_bound_object_cp;
-  bool has_hashmap = false;
-
-  if (*property_list_head_p != ECMA_NULL_POINTER)
-  {
-    /* If the first entry is a hashmap, it is skipped. */
-    ecma_property_header_t *first_property_p = ECMA_GET_NON_NULL_POINTER (ecma_property_header_t,
-                                                                          *property_list_head_p);
-
-    if (ECMA_PROPERTY_GET_TYPE (first_property_p->types + 0) == ECMA_PROPERTY_TYPE_HASHMAP)
-    {
-      property_list_head_p = &first_property_p->next_property_cp;
-      has_hashmap = true;
-    }
-  }
 
   if (*property_list_head_p != ECMA_NULL_POINTER)
   {
     /* If the first entry is free (deleted), it is reused. */
     ecma_property_header_t *first_property_p = ECMA_GET_NON_NULL_POINTER (ecma_property_header_t,
                                                                           *property_list_head_p);
+    bool has_hashmap = false;
+
+    if (ECMA_PROPERTY_GET_TYPE (first_property_p->types + 0) == ECMA_PROPERTY_TYPE_HASHMAP)
+    {
+      property_list_head_p = &first_property_p->next_property_cp;
+      first_property_p = ECMA_GET_NON_NULL_POINTER (ecma_property_header_t,
+                                                    *property_list_head_p);
+      has_hashmap = true;
+    }
 
     JERRY_ASSERT (ECMA_PROPERTY_IS_PROPERTY_PAIR (first_property_p));
 
@@ -457,6 +452,23 @@ ecma_create_property (ecma_object_t *object_p, /**< the object */
   /* Otherwise we create a new property pair and use its second value. */
   ecma_property_pair_t *first_property_pair_p = ecma_alloc_property_pair ();
 
+  /* Need to query property_list_head_p again and recheck the existennce
+   * of property hasmap, because ecma_alloc_property_pair may delete them. */
+  property_list_head_p = &object_p->property_list_or_bound_object_cp;
+  bool has_hashmap = false;
+
+  if (*property_list_head_p != ECMA_NULL_POINTER)
+  {
+    ecma_property_header_t *first_property_p = ECMA_GET_NON_NULL_POINTER (ecma_property_header_t,
+                                                                          *property_list_head_p);
+
+    if (ECMA_PROPERTY_GET_TYPE (first_property_p->types + 0) == ECMA_PROPERTY_TYPE_HASHMAP)
+    {
+      property_list_head_p = &first_property_p->next_property_cp;
+      has_hashmap = true;
+    }
+  }
+
   /* Just copy the previous value (no need to decompress, compress). */
   first_property_pair_p->header.next_property_cp = *property_list_head_p;
   first_property_pair_p->header.types[0].type_and_flags = ECMA_PROPERTY_TYPE_DELETED;