Introduce C API to query the type of an Error object (#2177)

New api function:
* jerry_get_error_type

Additionally update a few places where this new function
can be used.

JerryScript-DCO-1.0-Signed-off-by: Peter Gal pgal.u-szeged@partner.samsung.com

jerry-core/api/jerry.c

@@ -42,7 +42,8 @@
 JERRY_STATIC_ASSERT (sizeof (jerry_value_t) == sizeof (ecma_value_t),
                      size_of_jerry_value_t_must_be_equal_to_size_of_ecma_value_t);
 
-JERRY_STATIC_ASSERT ((int) ECMA_ERROR_COMMON == (int) JERRY_ERROR_COMMON
+JERRY_STATIC_ASSERT ((int) ECMA_ERROR_NONE == (int) JERRY_ERROR_NONE
+                     && (int) ECMA_ERROR_COMMON == (int) JERRY_ERROR_COMMON
                      && (int) ECMA_ERROR_EVAL == (int) JERRY_ERROR_EVAL
                      && (int) ECMA_ERROR_RANGE == (int) JERRY_ERROR_RANGE
                      && (int) ECMA_ERROR_REFERENCE == (int) JERRY_ERROR_REFERENCE
@@ -918,6 +919,28 @@ jerry_value_t jerry_get_value_without_error_flag (jerry_value_t value) /**< api
   return jerry_acquire_value (jerry_get_arg_value (value));
 } /* jerry_get_value_without_error_flag */
 
+/**
+ * Return the type of the Error object if possible.
+ *
+ * @return one of the jerry_error_t value as the type of the Error object
+ *         JERRY_ERROR_NONE - if the input value is not an Error object
+ */
+jerry_error_t
+jerry_get_error_type (const jerry_value_t value) /**< api value */
+{
+  jerry_value_t object = jerry_get_arg_value (value);
+
+  if (!ecma_is_value_object (object))
+  {
+    return JERRY_ERROR_NONE;
+  }
+
+  ecma_object_t *object_p = ecma_get_object_from_value (object);
+  ecma_standard_error_t error_type = ecma_get_error_type (object_p);
+
+  return error_type;
+} /* jerry_get_error_type */
+
 /**
  * Get boolean from the specified value.
  *

jerry-core/ecma/operations/ecma-exceptions.c

@@ -30,10 +30,36 @@
  * \addtogroup exceptions Exceptions
  * @{
  */
+typedef struct
+{
+  ecma_standard_error_t error_type;
+  ecma_builtin_id_t error_prototype_id;
+} ecma_error_mapping_t;
+
+const ecma_error_mapping_t ecma_error_mappings[] =
+{
+#define ERROR_ELEMENT(TYPE, ID) { TYPE, ID }
+  ERROR_ELEMENT (ECMA_ERROR_COMMON,      ECMA_BUILTIN_ID_ERROR_PROTOTYPE),
+
+#ifndef CONFIG_DISABLE_ERROR_BUILTINS
+  ERROR_ELEMENT (ECMA_ERROR_EVAL,        ECMA_BUILTIN_ID_EVAL_ERROR_PROTOTYPE),
+  ERROR_ELEMENT (ECMA_ERROR_RANGE,       ECMA_BUILTIN_ID_RANGE_ERROR_PROTOTYPE),
+  ERROR_ELEMENT (ECMA_ERROR_REFERENCE,   ECMA_BUILTIN_ID_REFERENCE_ERROR_PROTOTYPE),
+  ERROR_ELEMENT (ECMA_ERROR_TYPE,        ECMA_BUILTIN_ID_TYPE_ERROR_PROTOTYPE),
+  ERROR_ELEMENT (ECMA_ERROR_URI,         ECMA_BUILTIN_ID_URI_ERROR_PROTOTYPE),
+  ERROR_ELEMENT (ECMA_ERROR_SYNTAX,      ECMA_BUILTIN_ID_SYNTAX_ERROR_PROTOTYPE),
+#endif /* !CONFIG_DISABLE_ERROR_BUILTINS */
+
+#undef ERROR_ELEMENT
+};
 
 /**
  * Standard ecma-error object constructor.
  *
+ * Note:
+ *    calling with ECMA_ERROR_NONE does not make sense thus it will
+ *    cause a fault in the system.
+ *
  * @return pointer to ecma-object representing specified error
  *         with reference counter set to one.
  */
@@ -86,6 +112,12 @@ ecma_new_standard_error (ecma_standard_error_t error_type) /**< native error typ
       prototype_id = ECMA_BUILTIN_ID_SYNTAX_ERROR_PROTOTYPE;
       break;
     }
+
+    case ECMA_ERROR_NONE:
+    {
+      JERRY_UNREACHABLE ();
+      break;
+    }
   }
 #else
   JERRY_UNUSED (error_type);
@@ -105,6 +137,32 @@ ecma_new_standard_error (ecma_standard_error_t error_type) /**< native error typ
   return new_error_obj_p;
 } /* ecma_new_standard_error */
 
+/**
+ * Return the error type for an Error object.
+ *
+ * @return one of the ecma_standard_error_t value
+ *         if it is not an Error object then ECMA_ERROR_NONE will be returned
+ */
+ecma_standard_error_t
+ecma_get_error_type (ecma_object_t *error_object) /**< possible error object */
+{
+  ecma_object_t *prototype_p = ecma_get_object_prototype (error_object);
+  if (prototype_p != NULL)
+  {
+    uint8_t builtin_id = ecma_get_object_builtin_id (prototype_p);
+
+    for (uint8_t idx = 0; idx < sizeof (ecma_error_mappings) / sizeof (ecma_error_mappings[0]); idx++)
+    {
+      if (ecma_error_mappings[idx].error_prototype_id == builtin_id)
+      {
+        return ecma_error_mappings[idx].error_type;
+      }
+    }
+  }
+
+  return ECMA_ERROR_NONE;
+} /* ecma_get_error_type */
+
 /**
  * Standard ecma-error object constructor.
  *

jerry-core/ecma/operations/ecma-exceptions.h

@@ -39,6 +39,8 @@
  */
 typedef enum
 {
+  ECMA_ERROR_NONE,      /**< Not an Error */
+
   ECMA_ERROR_COMMON,    /**< Error */
   ECMA_ERROR_EVAL,      /**< EvalError */
   ECMA_ERROR_RANGE,     /**< RangeError */
@@ -48,6 +50,7 @@ typedef enum
   ECMA_ERROR_URI        /**< URIError */
 } ecma_standard_error_t;
 
+ecma_standard_error_t ecma_get_error_type (ecma_object_t *error_object);
 ecma_object_t *ecma_new_standard_error (ecma_standard_error_t error_type);
 ecma_object_t *ecma_new_standard_error_with_message (ecma_standard_error_t error_type, ecma_string_t *message_string_p);
 ecma_value_t ecma_raise_standard_error (ecma_standard_error_t error_type, const lit_utf8_byte_t *msg_p);

jerry-core/include/jerryscript-core.h

@@ -64,6 +64,8 @@ typedef enum
  */
 typedef enum
 {
+  JERRY_ERROR_NONE = 0,  /**< No Error */
+
   JERRY_ERROR_COMMON,    /**< Error */
   JERRY_ERROR_EVAL,      /**< EvalError */
   JERRY_ERROR_RANGE,     /**< RangeError */
@@ -299,6 +301,11 @@ void jerry_value_set_error_flag (jerry_value_t *value_p);
 void jerry_value_set_abort_flag (jerry_value_t *value_p);
 jerry_value_t jerry_get_value_without_error_flag (jerry_value_t value);
 
+/**
+ * Error object function(s).
+ */
+jerry_error_t jerry_get_error_type (const jerry_value_t value);
+
 /**
  * Getter functions of 'jerry_value_t'.
  */