Implement import.meta object (#4766)

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

docs/02.API-REFERENCE.md

@@ -952,6 +952,31 @@ typedef void (*jerry_module_state_changed_callback_t) (jerry_module_state_t new_
 **See also**
 - [jerry_module_set_state_changed_callback](#jerry_module_set_state_changed_callback)
 
+## jerry_module_import_meta_callback_t
+
+**Summary**
+
+Callback which is called when an import.meta expression of a module is evaluated the first time.
+The object returned by import.meta is passed as the `meta_object` argument to the callback, and
+the callback can set the initial status of the object (e.g. add properties or set prototype).
+
+**Prototype**
+
+```c
+typedef void (*jerry_module_import_meta_callback_t) (const jerry_value_t module,
+                                                     const jerry_value_t meta_object,
+                                                     void *user_p);
+```
+
+- `module` - module whose import.meta object is requested.
+- `meta_object` - import.meta object created for the module.
+- `user_p` - pointer passed to [jerry_module_set_import_meta_callback](#jerry_module_set_import_meta_callback).
+
+*New in version [[NEXT_RELEASE]]*.
+
+**See also**
+- [jerry_module_set_import_meta_callback](#jerry_module_set_import_meta_callback)
+
 ## jerry_native_module_evaluate_callback_t
 
 **Summary**
@@ -4996,13 +5021,12 @@ Sets a callback which is called after a module state is changed to linked, evalu
 **Prototype**
 
 ```c
-void
-jerry_module_set_state_changed_callback (jerry_module_state_changed_callback_t callback,
-                                         void *user_p)
+void jerry_module_set_state_changed_callback (jerry_module_state_changed_callback_t callback,
+                                              void *user_p);
 ```
 
 - `callback` - callback, which is called after the state change.
-- `module_val` - pointer passed to the callback function.
+- `user_p` - pointer passed to the callback function.
 
 *New in version [[NEXT_RELEASE]]*.
 
@@ -5060,6 +5084,82 @@ main (void)
 - [jerry_module_state_t](#jerry_module_state_t)
 - [jerry_module_state_changed_callback_t](#jerry_module_state_changed_callback_t)
 
+## jerry_module_set_import_meta_callback
+
+**Summary**
+
+Sets a callback which is called when an import.meta expression of a module is evaluated the first time.
+
+*Notes*:
+- This API depends on a build option (`JERRY_MODULE_SYSTEM`) and can be checked
+  in runtime with the `JERRY_FEATURE_MODULE` feature enum value,
+  see: [jerry_is_feature_enabled](#jerry_is_feature_enabled).
+
+**Prototype**
+
+```c
+void jerry_module_set_import_meta_callback (jerry_module_import_meta_callback_t callback,
+                                            void *user_p);
+```
+
+- `callback` - callback, which is called when an import.meta
+               expression of a module is evaluated the first time
+- `user_p` - pointer passed to the callback function.
+
+*New in version [[NEXT_RELEASE]]*.
+
+**Example**
+
+[doctest]: # (test="compile")
+
+```c
+#include <jerryscript.h>
+#include <stdio.h>
+
+static void
+module_import_meta_callback (const jerry_value_t module, /**< module */
+                             const jerry_value_t meta_object, /**< import.meta object */
+                             void *user_p) /**< user pointer */
+{
+  (void) user_p;
+
+  /* Create a property for the meta object */
+  jerry_value_t property_name_value = jerry_create_string ((const jerry_char_t *) "prop");
+  jerry_value_t property_value = jerry_create_string ((const jerry_char_t *) "prop");
+  jerry_value_t result_value = jerry_set_property (meta_object, property_name_value, property_value);
+  jerry_release_value (result_value);
+  jerry_release_value (property_value);
+  jerry_release_value (property_name_value);
+} /* module_import_meta_callback */
+
+int
+main (void)
+{
+  jerry_init (JERRY_INIT_EMPTY);
+
+  const jerry_char_t script[] = "import.meta";
+
+  jerry_module_set_import_meta_callback (module_import_meta_callback, NULL);
+
+  jerry_parse_options_t parse_options;
+  parse_options.options = JERRY_PARSE_MODULE;
+
+  jerry_value_t module_value = jerry_parse (script, sizeof (script) - 1, &parse_options);
+
+  jerry_release_value (jerry_module_link (module_value, NULL, NULL));
+  jerry_release_value (jerry_module_evaluate (module_value));
+
+  jerry_release_value (module_value);
+
+  jerry_cleanup ();
+  return 0;
+}
+```
+
+**See also**
+
+- [jerry_module_import_meta_callback_t](#jerry_module_import_meta_callback_t)
+
 ## jerry_module_get_number_of_requests
 
 **Summary**