Warning fixes.

ISO C99 doesn’t support unnamed structs/unions.
Comparison of distinct pointer types lacks a cast.
Dereferencing type-punned pointer will break strict-aliasing rules.
Type of bit-field ‘ext’ is a GCC extension.

JerryScript-DCO-1.0-Signed-off-by: Robert Sipka rsipka.uszeged@partner.samsung.com

19 files changed, 92 insertions, 87 deletions

diff --git a/jerry-core/ecma/base/ecma-globals.h b/jerry-core/ecma/base/ecma-globals.h
index 65de09b2..e806191d 100644
--- a/jerry-core/ecma/base/ecma-globals.h
+++ b/jerry-core/ecma/base/ecma-globals.h
@@ -294,8 +294,8 @@ typedef enum
  */
 typedef struct
 {
-  mem_cpointer_t getter_p : ECMA_POINTER_FIELD_WIDTH; /**< pointer to getter object */
-  mem_cpointer_t setter_p : ECMA_POINTER_FIELD_WIDTH; /**< pointer to setter object */
+  __extension__ mem_cpointer_t getter_p : ECMA_POINTER_FIELD_WIDTH; /**< pointer to getter object */
+  __extension__ mem_cpointer_t setter_p : ECMA_POINTER_FIELD_WIDTH; /**< pointer to setter object */
 } ecma_getter_setter_pointers_t;
 
 /**
@@ -307,7 +307,7 @@ typedef struct __attr_packed___ ecma_property_t
   unsigned int type : 2;
 
   /** Compressed pointer to next property */
-  mem_cpointer_t next_property_p : ECMA_POINTER_FIELD_WIDTH;
+  __extension__ mem_cpointer_t next_property_p : ECMA_POINTER_FIELD_WIDTH;
 
   /** Property's details (depending on Type) */
   union
@@ -316,10 +316,10 @@ typedef struct __attr_packed___ ecma_property_t
     struct __attr_packed___ ecma_named_data_property_t
     {
       /** Value */
-      ecma_value_t value : ECMA_VALUE_SIZE;
+      __extension__ ecma_value_t value : ECMA_VALUE_SIZE;
 
       /** Compressed pointer to property's name (pointer to String) */
-      mem_cpointer_t name_p : ECMA_POINTER_FIELD_WIDTH;
+      __extension__ mem_cpointer_t name_p : ECMA_POINTER_FIELD_WIDTH;
 
       /** Flag indicating whether the property is registered in LCache */
       unsigned int is_lcached : 1;
@@ -338,7 +338,7 @@ typedef struct __attr_packed___ ecma_property_t
     struct __attr_packed___ ecma_named_accessor_property_t
     {
       /** Compressed pointer to property's name (pointer to String) */
-      mem_cpointer_t name_p : ECMA_POINTER_FIELD_WIDTH;
+      __extension__ mem_cpointer_t name_p : ECMA_POINTER_FIELD_WIDTH;
 
       /** Attribute 'Enumerable' (ecma_property_enumerable_value_t) */
       unsigned int enumerable : 1;
@@ -350,7 +350,7 @@ typedef struct __attr_packed___ ecma_property_t
       unsigned int is_lcached : 1;
 
       /** Compressed pointer to pair of pointers - to property's getter and setter */
-      mem_cpointer_t getter_setter_pair_cp : ECMA_POINTER_FIELD_WIDTH;
+      __extension__ mem_cpointer_t getter_setter_pair_cp : ECMA_POINTER_FIELD_WIDTH;
     } named_accessor_property;
 
     /** Description of internal property */
@@ -795,10 +795,10 @@ typedef struct ecma_string_t
     lit_cpointer_t lit_cp;
 
     /** Compressed pointer to an ecma_collection_header_t */
-    mem_cpointer_t collection_cp : ECMA_POINTER_FIELD_WIDTH;
+    __extension__ mem_cpointer_t collection_cp : ECMA_POINTER_FIELD_WIDTH;
 
     /** Compressed pointer to an ecma_number_t */
-    mem_cpointer_t number_cp : ECMA_POINTER_FIELD_WIDTH;
+    __extension__ mem_cpointer_t number_cp : ECMA_POINTER_FIELD_WIDTH;
 
     /** UInt32-represented number placed locally in the descriptor */
     uint32_t uint32_number;
diff --git a/jerry-core/ecma/base/ecma-helpers-string.c b/jerry-core/ecma/base/ecma-helpers-string.c
index cf46e630..f989dcb4 100644
--- a/jerry-core/ecma/base/ecma-helpers-string.c
+++ b/jerry-core/ecma/base/ecma-helpers-string.c
@@ -978,7 +978,7 @@ ecma_compare_ecma_strings_longpath (const ecma_string_t *string1_p, /* ecma-stri
     {
       case ECMA_STRING_CONTAINER_LIT_TABLE:
       {
-        JERRY_ASSERT (string1_p->u.lit_cp.packed_value != string2_p->u.lit_cp.packed_value);
+        JERRY_ASSERT (string1_p->u.lit_cp.u.packed_value != string2_p->u.lit_cp.u.packed_value);
         return false;
       }
       case ECMA_STRING_CONTAINER_MAGIC_STRING:
diff --git a/jerry-core/ecma/base/ecma-helpers.c b/jerry-core/ecma/base/ecma-helpers.c
index b96c19ee..f8f34bbb 100644
--- a/jerry-core/ecma/base/ecma-helpers.c
+++ b/jerry-core/ecma/base/ecma-helpers.c
@@ -1388,7 +1388,7 @@ ecma_bytecode_deref (ecma_compiled_code_t *bytecode_p) /**< byte code pointer */
 
     for (uint32_t i = const_literal_end; i < literal_end; i++)
     {
-      mem_cpointer_t bytecode_cpointer = literal_start_p[i].value.base_cp;
+      mem_cpointer_t bytecode_cpointer = literal_start_p[i].u.value.base_cp;
       ecma_compiled_code_t *bytecode_literal_p = ECMA_GET_NON_NULL_POINTER (ecma_compiled_code_t,
                                                                             bytecode_cpointer);
 
diff --git a/jerry-core/ecma/operations/ecma-objects-arguments.c b/jerry-core/ecma/operations/ecma-objects-arguments.c
index a0a3198f..4483269f 100644
--- a/jerry-core/ecma/operations/ecma-objects-arguments.c
+++ b/jerry-core/ecma/operations/ecma-objects-arguments.c
@@ -138,7 +138,7 @@ ecma_op_create_arguments_object (ecma_object_t *func_obj_p, /**< callee function
            indx++)
       {
         // i.
-        if (literal_p[indx].packed_value == MEM_CP_NULL)
+        if (literal_p[indx].u.packed_value == MEM_CP_NULL)
         {
           continue;
         }
diff --git a/jerry-core/ecma/operations/ecma-reference.h b/jerry-core/ecma/operations/ecma-reference.h
index 1cfd4838..9b25eb17 100644
--- a/jerry-core/ecma/operations/ecma-reference.h
+++ b/jerry-core/ecma/operations/ecma-reference.h
@@ -37,7 +37,7 @@ typedef struct
   ecma_value_t base;
 
   /** referenced name */
-  mem_cpointer_t referenced_name_cp : ECMA_POINTER_FIELD_WIDTH;
+  __extension__ mem_cpointer_t referenced_name_cp : ECMA_POINTER_FIELD_WIDTH;
 
   /** strict reference flag */
   unsigned int is_strict : 1;
diff --git a/jerry-core/jerry-api.h b/jerry-core/jerry-api.h
index 5a76eee6..0913a01f 100644
--- a/jerry-core/jerry-api.h
+++ b/jerry-core/jerry-api.h
@@ -118,12 +118,10 @@ typedef struct jerry_api_value_t
 
     uint32_t v_uint32; /**< number converted 32-bit unsigned integer */
 
-    union
-    {
-      jerry_api_string_t *v_string; /**< pointer to a JS string */
-      jerry_api_object_t *v_object; /**< pointer to a JS object */
-    };
-  };
+    jerry_api_string_t *v_string; /**< pointer to a JS string */
+    jerry_api_object_t *v_object; /**< pointer to a JS object */
+
+  } u;
 } jerry_api_value_t;
 
 /**
diff --git a/jerry-core/jerry-snapshot.h b/jerry-core/jerry-snapshot.h
index 5b35af3b..9c9ce316 100644
--- a/jerry-core/jerry-snapshot.h
+++ b/jerry-core/jerry-snapshot.h
@@ -26,9 +26,9 @@ typedef struct
 {
   uint32_t last_compiled_code_offset; /**< offset of the last compiled code */
   uint32_t lit_table_size; /**< size of literal table */
-  uint32_t is_run_global : 1; /**< flag, indicating whether the snapshot
-                               *   was dumped as 'Global scope'-mode code (true)
-                               *   or as eval-mode code (false) */
+  __extension__ uint32_t is_run_global : 1; /**< flag, indicating whether the snapshot
+                                             *   was dumped as 'Global scope'-mode code (true)
+                                             *   or as eval-mode code (false) */
 } jerry_snapshot_header_t;
 
 /**
diff --git a/jerry-core/jerry.c b/jerry-core/jerry.c
index 7a9006a8..7ad48c02 100644
--- a/jerry-core/jerry.c
+++ b/jerry-core/jerry.c
@@ -205,7 +205,7 @@ jerry_api_value_is_object (const jerry_api_value_t *value_p) /**< pointer to api
 bool
 jerry_api_value_is_function (const jerry_api_value_t *value_p) /**< pointer to api value */
 {
-  return jerry_api_value_is_object (value_p) && jerry_api_is_function (value_p->v_object);
+  return jerry_api_value_is_object (value_p) && jerry_api_is_function (value_p->u.v_object);
 } /* jerry_api_value_is_function */
 
 /**
@@ -217,7 +217,7 @@ bool
 jerry_api_get_boolean_value (const jerry_api_value_t *value_p) /**< pointer to api value */
 {
   JERRY_ASSERT (jerry_api_value_is_boolean (value_p));
-  return value_p->v_bool;
+  return value_p->u.v_bool;
 } /* jerry_api_get_boolean_value */
 
 /**
@@ -237,15 +237,15 @@ jerry_api_get_number_value (const jerry_api_value_t *value_p) /**< pointer to ap
   JERRY_ASSERT (jerry_api_value_is_number (value_p));
   if (value_p->type == JERRY_API_DATA_TYPE_UINT32)
   {
-    return value_p->v_uint32;
+    return value_p->u.v_uint32;
   }
   else if (value_p->type == JERRY_API_DATA_TYPE_FLOAT32)
   {
-    return value_p->v_float32;
+    return value_p->u.v_float32;
   }
   else
   {
-    return value_p->v_float64;
+    return value_p->u.v_float64;
   }
 } /* jerry_api_get_number_value */
 
@@ -258,7 +258,7 @@ jerry_api_string_t *
 jerry_api_get_string_value (const jerry_api_value_t *value_p) /**< pointer to api value */
 {
   JERRY_ASSERT (jerry_api_value_is_string (value_p));
-  return value_p->v_string;
+  return value_p->u.v_string;
 } /* jerry_api_get_string_value */
 
 /**
@@ -270,7 +270,7 @@ jerry_api_object_t *
 jerry_api_get_object_value (const jerry_api_value_t *value_p) /**< pointer to api value */
 {
   JERRY_ASSERT (jerry_api_value_is_object (value_p));
-  return value_p->v_object;
+  return value_p->u.v_object;
 } /* jerry_api_get_object_value */
 
 /**
@@ -318,7 +318,7 @@ jerry_api_create_boolean_value (bool value) /**< bool value from which a jerry_a
 {
   jerry_api_value_t jerry_val;
   jerry_val.type = JERRY_API_DATA_TYPE_BOOLEAN;
-  jerry_val.v_bool = value;
+  jerry_val.u.v_bool = value;
   return jerry_val;
 } /* jerry_api_create_boolean_value */
 
@@ -332,7 +332,7 @@ jerry_api_create_number_value (double value) /**< double value from which a jerr
 {
   jerry_api_value_t jerry_val;
   jerry_val.type = JERRY_API_DATA_TYPE_FLOAT64;
-  jerry_val.v_float64 = value;
+  jerry_val.u.v_float64 = value;
   return jerry_val;
 } /* jerry_api_create_number_value */
 
@@ -345,7 +345,7 @@ jerry_api_create_object_value (jerry_api_object_t *value) /**< jerry_api_object_
 {
   jerry_api_value_t jerry_val;
   jerry_val.type = JERRY_API_DATA_TYPE_OBJECT;
-  jerry_val.v_object = value;
+  jerry_val.u.v_object = value;
   return jerry_val;
 } /* jerry_api_create_object_value */
 
@@ -358,7 +358,7 @@ jerry_api_create_string_value (jerry_api_string_t *value) /**< jerry_api_string_
 {
   jerry_api_value_t jerry_val;
   jerry_val.type = JERRY_API_DATA_TYPE_STRING;
-  jerry_val.v_string = value;
+  jerry_val.u.v_string = value;
   return jerry_val;
 } /* jerry_api_create_string_value */
 
@@ -391,7 +391,7 @@ jerry_api_convert_ecma_value_to_api_value (jerry_api_value_t *out_value_p, /**<
   else if (ecma_is_value_boolean (value))
   {
     out_value_p->type = JERRY_API_DATA_TYPE_BOOLEAN;
-    out_value_p->v_bool = ecma_is_value_true (value);
+    out_value_p->u.v_bool = ecma_is_value_true (value);
   }
   else if (ecma_is_value_number (value))
   {
@@ -399,10 +399,10 @@ jerry_api_convert_ecma_value_to_api_value (jerry_api_value_t *out_value_p, /**<
 
 #if CONFIG_ECMA_NUMBER_TYPE == CONFIG_ECMA_NUMBER_FLOAT32
     out_value_p->type = JERRY_API_DATA_TYPE_FLOAT32;
-    out_value_p->v_float32 = *num;
+    out_value_p->u.v_float32 = *num;
 #elif CONFIG_ECMA_NUMBER_TYPE == CONFIG_ECMA_NUMBER_FLOAT64
     out_value_p->type = JERRY_API_DATA_TYPE_FLOAT64;
-    out_value_p->v_float64 = *num;
+    out_value_p->u.v_float64 = *num;
 #endif /* CONFIG_ECMA_NUMBER_TYPE == CONFIG_ECMA_NUMBER_FLOAT64 */
   }
   else if (ecma_is_value_string (value))
@@ -410,7 +410,7 @@ jerry_api_convert_ecma_value_to_api_value (jerry_api_value_t *out_value_p, /**<
     ecma_string_t *str = ecma_get_string_from_value (value);
 
     out_value_p->type = JERRY_API_DATA_TYPE_STRING;
-    out_value_p->v_string = ecma_copy_or_ref_ecma_string (str);
+    out_value_p->u.v_string = ecma_copy_or_ref_ecma_string (str);
   }
   else if (ecma_is_value_object (value))
   {
@@ -418,7 +418,7 @@ jerry_api_convert_ecma_value_to_api_value (jerry_api_value_t *out_value_p, /**<
     ecma_ref_object (obj);
 
     out_value_p->type = JERRY_API_DATA_TYPE_OBJECT;
-    out_value_p->v_object = obj;
+    out_value_p->u.v_object = obj;
   }
   else
   {
@@ -453,14 +453,14 @@ jerry_api_convert_api_value_to_ecma_value (ecma_value_t *out_value_p, /**< out:
     }
     case JERRY_API_DATA_TYPE_BOOLEAN:
     {
-      *out_value_p = ecma_make_simple_value (api_value_p->v_bool ? ECMA_SIMPLE_VALUE_TRUE : ECMA_SIMPLE_VALUE_FALSE);
+      *out_value_p = ecma_make_simple_value (api_value_p->u.v_bool ? ECMA_SIMPLE_VALUE_TRUE : ECMA_SIMPLE_VALUE_FALSE);
 
       break;
     }
     case JERRY_API_DATA_TYPE_FLOAT32:
     {
       ecma_number_t *num = ecma_alloc_number ();
-      *num = (ecma_number_t) (api_value_p->v_float32);
+      *num = (ecma_number_t) (api_value_p->u.v_float32);
 
       *out_value_p = ecma_make_number_value (num);
 
@@ -469,7 +469,7 @@ jerry_api_convert_api_value_to_ecma_value (ecma_value_t *out_value_p, /**< out:
     case JERRY_API_DATA_TYPE_FLOAT64:
     {
       ecma_number_t *num = ecma_alloc_number ();
-      *num = (ecma_number_t) (api_value_p->v_float64);
+      *num = (ecma_number_t) (api_value_p->u.v_float64);
 
       *out_value_p = ecma_make_number_value (num);
 
@@ -478,7 +478,7 @@ jerry_api_convert_api_value_to_ecma_value (ecma_value_t *out_value_p, /**< out:
     case JERRY_API_DATA_TYPE_UINT32:
     {
       ecma_number_t *num = ecma_alloc_number ();
-      *num = (ecma_number_t) (api_value_p->v_uint32);
+      *num = (ecma_number_t) (api_value_p->u.v_uint32);
 
       *out_value_p = ecma_make_number_value (num);
 
@@ -486,7 +486,7 @@ jerry_api_convert_api_value_to_ecma_value (ecma_value_t *out_value_p, /**< out:
     }
     case JERRY_API_DATA_TYPE_STRING:
     {
-      ecma_string_t *str_p = ecma_copy_or_ref_ecma_string (api_value_p->v_string);
+      ecma_string_t *str_p = ecma_copy_or_ref_ecma_string (api_value_p->u.v_string);
 
       *out_value_p = ecma_make_string_value (str_p);
 
@@ -494,7 +494,7 @@ jerry_api_convert_api_value_to_ecma_value (ecma_value_t *out_value_p, /**< out:
     }
     case JERRY_API_DATA_TYPE_OBJECT:
     {
-      ecma_object_t *obj_p = api_value_p->v_object;
+      ecma_object_t *obj_p = api_value_p->u.v_object;
 
       ecma_ref_object (obj_p);
 
@@ -654,11 +654,11 @@ jerry_api_release_value (jerry_api_value_t *value_p) /**< API value */
 
   if (value_p->type == JERRY_API_DATA_TYPE_STRING)
   {
-    jerry_api_release_string (value_p->v_string);
+    jerry_api_release_string (value_p->u.v_string);
   }
   else if (value_p->type == JERRY_API_DATA_TYPE_OBJECT)
   {
-    jerry_api_release_object (value_p->v_object);
+    jerry_api_release_object (value_p->u.v_object);
   }
 } /* jerry_api_release_value */
 
@@ -2040,14 +2040,14 @@ jerry_snapshot_set_offsets (uint8_t *buffer_p, /**< buffer */
       {
         lit_mem_to_snapshot_id_map_entry_t *current_p = lit_map_p;
 
-        if (literal_start_p[i].packed_value != MEM_CP_NULL)
+        if (literal_start_p[i].u.packed_value != MEM_CP_NULL)
         {
-          while (current_p->literal_id.packed_value != literal_start_p[i].packed_value)
+          while (current_p->literal_id.u.packed_value != literal_start_p[i].u.packed_value)
           {
             current_p++;
           }
 
-          literal_start_p[i].packed_value = (uint16_t) current_p->literal_offset;
+          literal_start_p[i].u.packed_value = (uint16_t) current_p->literal_offset;
         }
       }
 
@@ -2055,13 +2055,13 @@ jerry_snapshot_set_offsets (uint8_t *buffer_p, /**< buffer */
       {
         compiled_code_map_entry_t *current_p = snapshot_map_entries_p;
 
-        while (current_p->compiled_code_cp != literal_start_p[i].value.base_cp)
+        while (current_p->compiled_code_cp != literal_start_p[i].u.value.base_cp)
         {
           current_p = ECMA_GET_NON_NULL_POINTER (compiled_code_map_entry_t,
                                                  current_p->next_cp);
         }
 
-        literal_start_p[i].packed_value = (uint16_t) current_p->offset;
+        literal_start_p[i].u.packed_value = (uint16_t) current_p->offset;
       }
     }
 
@@ -2315,9 +2315,9 @@ snapshot_load_compiled_code (const uint8_t *snapshot_data_p, /**< snapshot data
   {
     lit_mem_to_snapshot_id_map_entry_t *current_p = lit_map_p;
 
-    if (literal_start_p[i].packed_value != 0)
+    if (literal_start_p[i].u.packed_value != 0)
     {
-      while (current_p->literal_offset != literal_start_p[i].packed_value)
+      while (current_p->literal_offset != literal_start_p[i].u.packed_value)
       {
         current_p++;
       }
@@ -2328,12 +2328,12 @@ snapshot_load_compiled_code (const uint8_t *snapshot_data_p, /**< snapshot data
 
   for (uint32_t i = const_literal_end; i < literal_end; i++)
   {
-    size_t literal_offset = ((size_t) literal_start_p[i].packed_value) << MEM_ALIGNMENT_LOG;
+    size_t literal_offset = ((size_t) literal_start_p[i].u.packed_value) << MEM_ALIGNMENT_LOG;
 
     if (literal_offset == offset)
     {
       /* Self reference */
-      ECMA_SET_NON_NULL_POINTER (literal_start_p[i].value.base_cp,
+      ECMA_SET_NON_NULL_POINTER (literal_start_p[i].u.value.base_cp,
                                  bytecode_p);
     }
     else
@@ -2344,7 +2344,7 @@ snapshot_load_compiled_code (const uint8_t *snapshot_data_p, /**< snapshot data
                                                         lit_map_p,
                                                         copy_bytecode);
 
-      ECMA_SET_NON_NULL_POINTER (literal_start_p[i].value.base_cp,
+      ECMA_SET_NON_NULL_POINTER (literal_start_p[i].u.value.base_cp,
                                  literal_bytecode_p);
     }
   }
diff --git a/jerry-core/jrt/jrt.h b/jerry-core/jrt/jrt.h
index 2c67f67c..6f0603ad 100644
--- a/jerry-core/jrt/jrt.h
+++ b/jerry-core/jrt/jrt.h
@@ -42,6 +42,10 @@
 # define __attr_pure___ __attribute__((pure))
 #endif /* !__attr_pure___ */
 
+#ifndef __GNUC__
+#define __extension__
+#endif /* !__GNUC__ */
+
 /**
  * Constants
  */
diff --git a/jerry-core/lit/lit-literal.c b/jerry-core/lit/lit-literal.c
index 02df1132..ec1bdb57 100644
--- a/jerry-core/lit/lit-literal.c
+++ b/jerry-core/lit/lit-literal.c
@@ -570,7 +570,7 @@ lit_literal_exists (lit_literal_t lit) /**< literal to check for existence */
 lit_literal_t
 lit_get_literal_by_cp (rcs_cpointer_t lit_cp) /**< compressed pointer to literal */
 {
-  JERRY_ASSERT (lit_cp.packed_value != MEM_CP_NULL);
+  JERRY_ASSERT (lit_cp.u.packed_value != MEM_CP_NULL);
   lit_literal_t lit = rcs_cpointer_decompress (lit_cp);
   JERRY_ASSERT (lit_literal_exists (lit));
 
diff --git a/jerry-core/lit/lit-strings.h b/jerry-core/lit/lit-strings.h
index bb101d0a..84baeca6 100644
--- a/jerry-core/lit/lit-strings.h
+++ b/jerry-core/lit/lit-strings.h
@@ -99,7 +99,7 @@
  */
 typedef struct
 {
-  lit_utf8_size_t offset : LIT_ITERATOR_OFFSET_WIDTH; /** offset to utf-8 char */
+  __extension__ lit_utf8_size_t offset : LIT_ITERATOR_OFFSET_WIDTH; /** offset to utf-8 char */
   bool is_non_bmp_middle: 1; /** flag indicating that current position of the iterator is the middle of
                               *  4-byte char */
 } lit_utf8_iterator_pos_t;
diff --git a/jerry-core/mem/mem-heap.c b/jerry-core/mem/mem-heap.c
index 6b76a566..76554842 100644
--- a/jerry-core/mem/mem-heap.c
+++ b/jerry-core/mem/mem-heap.c
@@ -760,7 +760,7 @@ mem_heap_get_chunked_block_start (void *ptr) /**< pointer into a block */
   JERRY_STATIC_ASSERT ((MEM_HEAP_CHUNK_SIZE & (MEM_HEAP_CHUNK_SIZE - 1u)) == 0);
   JERRY_STATIC_ASSERT (((uintptr_t) mem_heap.area % MEM_HEAP_CHUNK_SIZE) == 0);
 
-  JERRY_ASSERT (mem_heap.area <= ptr && ptr < (uint8_t *) mem_heap.area + MEM_HEAP_AREA_SIZE);
+  JERRY_ASSERT (mem_heap.area <= (uint8_t *) ptr && (uint8_t *) ptr < (uint8_t *) mem_heap.area + MEM_HEAP_AREA_SIZE);
 
   uintptr_t uintptr = (uintptr_t) ptr;
   uintptr_t uintptr_chunk_aligned = JERRY_ALIGNDOWN (uintptr, MEM_HEAP_CHUNK_SIZE);
diff --git a/jerry-core/parser/js/js-lexer.c b/jerry-core/parser/js/js-lexer.c
index 52fbc954..d8fe4e8c 100644
--- a/jerry-core/parser/js/js-lexer.c
+++ b/jerry-core/parser/js/js-lexer.c
@@ -1572,7 +1572,7 @@ lexer_construct_number_object (parser_context_t *context_p, /**< context */
   while ((literal_p = (lexer_literal_t *) parser_list_iterator_next (&literal_iterator)) != NULL)
   {
     if (literal_p->type == LEXER_NUMBER_LITERAL
-        && literal_p->u.value.value.base_cp == lit_cp.value.base_cp)
+        && literal_p->u.value.u.value.base_cp == lit_cp.u.value.base_cp)
     {
       context_p->lit_object.literal_p = literal_p;
       context_p->lit_object.index = (uint16_t) literal_index;
diff --git a/jerry-core/parser/js/js-parser.c b/jerry-core/parser/js/js-parser.c
index 894eda96..c62ce6d5 100644
--- a/jerry-core/parser/js/js-parser.c
+++ b/jerry-core/parser/js/js-parser.c
@@ -535,7 +535,7 @@ parser_generate_initializers (parser_context_t *context_p, /**< context */
       else if ((literal_p->type == LEXER_FUNCTION_LITERAL)
                || (literal_p->type == LEXER_REGEXP_LITERAL))
       {
-        ECMA_SET_NON_NULL_POINTER (literal_pool_p[literal_p->prop.index].value.base_cp,
+        ECMA_SET_NON_NULL_POINTER (literal_pool_p[literal_p->prop.index].u.value.base_cp,
                                    literal_p->u.bytecode_p);
       }
       else
@@ -579,7 +579,7 @@ parser_generate_initializers (parser_context_t *context_p, /**< context */
         JERRY_ASSERT (literal_p != NULL
                        && literal_p->type == LEXER_FUNCTION_LITERAL);
         init_index = literal_p->prop.index;
-        ECMA_SET_NON_NULL_POINTER (literal_pool_p[literal_p->prop.index].value.base_cp,
+        ECMA_SET_NON_NULL_POINTER (literal_pool_p[literal_p->prop.index].u.value.base_cp,
                                    literal_p->u.bytecode_p);
       }
 
@@ -1775,7 +1775,7 @@ parser_post_processing (parser_context_t *context_p) /**< context */
 
   if (context_p->status_flags & PARSER_NAMED_FUNCTION_EXP)
   {
-    ECMA_SET_NON_NULL_POINTER (literal_pool_p[const_literal_end].value.base_cp,
+    ECMA_SET_NON_NULL_POINTER (literal_pool_p[const_literal_end].u.value.base_cp,
                                compiled_code_p);
   }
 
diff --git a/jerry-core/rcs/rcs-cpointer.c b/jerry-core/rcs/rcs-cpointer.c
index 3e98325f..b0a805ec 100644
--- a/jerry-core/rcs/rcs-cpointer.c
+++ b/jerry-core/rcs/rcs-cpointer.c
@@ -26,17 +26,17 @@ rcs_cpointer_t
 rcs_cpointer_compress (rcs_record_t *pointer) /**< pointer to compress */
 {
   rcs_cpointer_t cpointer;
-  cpointer.packed_value = 0;
+  cpointer.u.packed_value = 0;
 
   uintptr_t base_pointer = JERRY_ALIGNDOWN ((uintptr_t) pointer, MEM_ALIGNMENT);
 
   if ((void *) base_pointer == NULL)
   {
-    cpointer.value.base_cp = MEM_CP_NULL;
+    cpointer.u.value.base_cp = MEM_CP_NULL;
   }
   else
   {
-    cpointer.value.base_cp = mem_compress_pointer ((void *) base_pointer) & MEM_CP_MASK;
+    cpointer.u.value.base_cp = mem_compress_pointer ((void *) base_pointer) & MEM_CP_MASK;
   }
 
 #if MEM_ALIGNMENT_LOG > RCS_DYN_STORAGE_LENGTH_UNIT_LOG
@@ -55,7 +55,7 @@ rcs_cpointer_compress (rcs_record_t *pointer) /**< pointer to compress */
                                                           RCS_DYN_STORAGE_LENGTH_UNIT_LOG,
                                                           MEM_ALIGNMENT_LOG - RCS_DYN_STORAGE_LENGTH_UNIT_LOG);
 
-  cpointer.value.ext = ext_part & ((1ull << (MEM_ALIGNMENT_LOG - RCS_DYN_STORAGE_LENGTH_UNIT_LOG)) - 1);
+  cpointer.u.value.ext = ext_part & ((1ull << (MEM_ALIGNMENT_LOG - RCS_DYN_STORAGE_LENGTH_UNIT_LOG)) - 1);
 #endif /* MEM_ALIGNMENT > RCS_DYN_STORAGE_LENGTH_UNIT_LOG */
   JERRY_ASSERT (rcs_cpointer_decompress (cpointer) == pointer);
 
@@ -72,9 +72,9 @@ rcs_cpointer_decompress (rcs_cpointer_t compressed_pointer) /**< recordset-speci
 {
   uint8_t *base_pointer = NULL;
 
-  if (compressed_pointer.value.base_cp != MEM_CP_NULL)
+  if (compressed_pointer.u.value.base_cp != MEM_CP_NULL)
   {
-    base_pointer = (uint8_t *) mem_decompress_pointer (compressed_pointer.value.base_cp);
+    base_pointer = (uint8_t *) mem_decompress_pointer (compressed_pointer.u.value.base_cp);
   }
 
   uintptr_t diff = 0;
@@ -84,7 +84,7 @@ rcs_cpointer_decompress (rcs_cpointer_t compressed_pointer) /**< recordset-speci
    *     rcs_cpointer_compress
    */
 
-  diff = (uintptr_t) compressed_pointer.value.ext << RCS_DYN_STORAGE_LENGTH_UNIT_LOG;
+  diff = (uintptr_t) compressed_pointer.u.value.ext << RCS_DYN_STORAGE_LENGTH_UNIT_LOG;
 #endif /* MEM_ALIGNMENT_LOG > RCS_DYN_STORAGE_LENGTH_UNIT_LOG */
   rcs_record_t *rec_p = (rcs_record_t *) (base_pointer + diff);
 
@@ -99,6 +99,6 @@ rcs_cpointer_decompress (rcs_cpointer_t compressed_pointer) /**< recordset-speci
 rcs_cpointer_t rcs_cpointer_null_cp (void)
 {
   rcs_cpointer_t cp;
-  cp.packed_value = MEM_CP_NULL;
+  cp.u.packed_value = MEM_CP_NULL;
   return cp;
 } /* rcs_cpointer_null_cp */
diff --git a/jerry-core/rcs/rcs-cpointer.h b/jerry-core/rcs/rcs-cpointer.h
index cf9339a2..f8ba22ee 100644
--- a/jerry-core/rcs/rcs-cpointer.h
+++ b/jerry-core/rcs/rcs-cpointer.h
@@ -34,16 +34,16 @@ typedef struct
   {
     struct
     {
-      mem_cpointer_t base_cp : MEM_CP_WIDTH; /**< pointer to base of addressed area */
+      __extension__ mem_cpointer_t base_cp : MEM_CP_WIDTH; /**< pointer to base of addressed area */
 #if MEM_ALIGNMENT_LOG > RCS_DYN_STORAGE_LENGTH_UNIT_LOG
-      uint16_t ext : (MEM_ALIGNMENT_LOG - RCS_DYN_STORAGE_LENGTH_UNIT_LOG); /**< extension of the basic
-                                                                             *   compressed pointer
-                                                                             *   used for more detailed
-                                                                             *   addressing */
+      __extension__ uint16_t ext : (MEM_ALIGNMENT_LOG - RCS_DYN_STORAGE_LENGTH_UNIT_LOG); /**< extension of the basic
+                                                                                           *   compressed pointer
+                                                                                           *   used for more detailed
+                                                                                           *   addressing */
 #endif /* MEM_ALIGNMENT_LOG > RCS_DYN_STORAGE_LENGTH_UNIT_LOG */
     } value;
     uint16_t packed_value;
-  };
+  } u;
 } rcs_cpointer_t;
 
 extern rcs_cpointer_t rcs_cpointer_compress (rcs_record_t *);
diff --git a/jerry-core/rcs/rcs-records.c b/jerry-core/rcs/rcs-records.c
index de9cf09b..50332cf8 100644
--- a/jerry-core/rcs/rcs-records.c
+++ b/jerry-core/rcs/rcs-records.c
@@ -68,7 +68,7 @@ rcs_record_set_prev (rcs_record_set_t *rec_sec_p, /**< recordset */
       rcs_iterator_t it_ctx = rcs_iterator_create (rec_sec_p, rec_p);
 
       rcs_iterator_skip (&it_ctx, RCS_DYN_STORAGE_LENGTH_UNIT);
-      rcs_iterator_write (&it_ctx, &prev_cpointer.packed_value, sizeof (uint16_t));
+      rcs_iterator_write (&it_ctx, &prev_cpointer.u.packed_value, sizeof (uint16_t));
 
       return;
     }
@@ -95,7 +95,7 @@ rcs_record_set_prev (rcs_record_set_t *rec_sec_p, /**< recordset */
   }
 
   rcs_cpointer_t cpointer = rcs_cpointer_compress (prev_p);
-  rcs_record_set_field (rec_p, begin_pos, RCS_CPOINTER_WIDTH, cpointer.packed_value);
+  rcs_record_set_field (rec_p, begin_pos, RCS_CPOINTER_WIDTH, cpointer.u.packed_value);
 } /* rcs_record_set_prev */
 
 /**
@@ -239,10 +239,10 @@ rcs_record_get_pointer (rcs_record_t *rec_p, /**< record */
 
   uint16_t value = (uint16_t) rcs_record_get_field (rec_p, field_pos, field_width);
 
-  JERRY_ASSERT (sizeof (cpointer) == sizeof (cpointer.value));
-  JERRY_ASSERT (sizeof (value) == sizeof (cpointer.value));
+  JERRY_ASSERT (sizeof (cpointer) == sizeof (cpointer.u.value));
+  JERRY_ASSERT (sizeof (value) == sizeof (cpointer.u.value));
 
-  cpointer.packed_value = value;
+  cpointer.u.packed_value = value;
 
   return rcs_cpointer_decompress (cpointer);
 } /* rcs_record_get_pointer */
@@ -279,7 +279,7 @@ rcs_record_get_prev (rcs_record_set_t *rec_sec_p, /**< recordset */
       rcs_iterator_t it_ctx = rcs_iterator_create (rec_sec_p, rec_p);
 
       rcs_iterator_skip (&it_ctx, RCS_DYN_STORAGE_LENGTH_UNIT);
-      rcs_iterator_read (&it_ctx, &cpointer.packed_value, sizeof (uint16_t));
+      rcs_iterator_read (&it_ctx, &cpointer.u.packed_value, sizeof (uint16_t));
 
       return rcs_cpointer_decompress (cpointer);
     }
diff --git a/jerry-core/vm/vm-stack.c b/jerry-core/vm/vm-stack.c
index 7fbd081e..f2066584 100644
--- a/jerry-core/vm/vm-stack.c
+++ b/jerry-core/vm/vm-stack.c
@@ -75,7 +75,8 @@ vm_stack_context_abort (vm_frame_ctx_t *frame_ctx_p, /**< frame context */
         ecma_collection_chunk_t *chunk_p = MEM_CP_GET_NON_NULL_POINTER (ecma_collection_chunk_t,
                                                                         current);
 
-        ecma_free_value (*(ecma_value_t *) chunk_p->data, true);
+        lit_utf8_byte_t *data_ptr = chunk_p->data;
+        ecma_free_value (*(ecma_value_t *) data_ptr, true);
 
         current = chunk_p->next_chunk_cp;
         ecma_dealloc_collection_chunk (chunk_p);
diff --git a/jerry-core/vm/vm.c b/jerry-core/vm/vm.c
index 8d10080d..104c7c30 100644
--- a/jerry-core/vm/vm.c
+++ b/jerry-core/vm/vm.c
@@ -281,7 +281,7 @@ vm_construct_literal_object (vm_frame_ctx_t *frame_ctx_p, /**< frame context */
                              lit_cpointer_t lit_cp) /**< literal */
 {
   ecma_compiled_code_t *bytecode_p = ECMA_GET_NON_NULL_POINTER (ecma_compiled_code_t,
-                                                                lit_cp.value.base_cp);
+                                                                lit_cp.u.value.base_cp);
   bool is_function = ((bytecode_p->status_flags & CBC_CODE_FLAGS_FUNCTION) != 0);
 
   if (is_function)
@@ -1859,7 +1859,8 @@ vm_loop (vm_frame_ctx_t *frame_ctx_p) /**< frame context */
 
           JERRY_ASSERT (VM_GET_CONTEXT_TYPE (context_top_p[-1]) == VM_CONTEXT_FOR_IN);
 
-          result = *(ecma_value_t *) chunk_p->data;
+          lit_utf8_byte_t *data_ptr = chunk_p->data;
+          result = *(ecma_value_t *) data_ptr;
           context_top_p[-2] = chunk_p->next_chunk_cp;
 
           ecma_dealloc_collection_chunk (chunk_p);
@@ -1882,7 +1883,8 @@ vm_loop (vm_frame_ctx_t *frame_ctx_p) /**< frame context */
 
             ecma_collection_chunk_t *chunk_p = MEM_CP_GET_NON_NULL_POINTER (ecma_collection_chunk_t, stack_top_p[-2]);
 
-            ecma_string_t *prop_name_p = ecma_get_string_from_value (*(ecma_value_t *) chunk_p->data);
+            lit_utf8_byte_t *data_ptr = chunk_p->data;
+            ecma_string_t *prop_name_p = ecma_get_string_from_value (*(ecma_value_t *) data_ptr);
 
             if (ecma_op_object_get_property (ecma_get_object_from_value (stack_top_p[-3]),
                                              prop_name_p) == NULL)