module extension: add support for canonical name resolution (#2013)

Before attempting to load a module, each provided resolver must be given an
opportunity to examine the name of the requested module without actually
loading it so as to canonicalize it, in case a module can be referred to by
multiple names.

Then, modules are loaded and cached by their canonical name.

JerryScript-DCO-1.0-Signed-off-by: Gabriel Schulhof gabriel.schulhof@intel.com

jerry-ext/include/jerryscript-ext/module.h

@@ -30,7 +30,7 @@ typedef jerry_value_t (*jerryx_native_module_on_resolve_t) (void);
 typedef struct jerryx_native_module_t
 {
   const jerry_char_t *name_p; /**< name of the module */
-  const jerryx_native_module_on_resolve_t on_resolve; /**< function that returns a new instance of the module */
+  const jerryx_native_module_on_resolve_t on_resolve_p; /**< function that returns a new instance of the module */
   struct jerryx_native_module_t *next_p; /**< pointer to next module in the list */
 } jerryx_native_module_t;
 
@@ -58,7 +58,7 @@ typedef struct jerryx_native_module_t
   static jerryx_native_module_t _ ## module_name ## _definition =      \
   {                                                                    \
     .name_p = (jerry_char_t *) #module_name,                           \
-    .on_resolve = (on_resolve_cb),                                     \
+    .on_resolve_p = (on_resolve_cb),                                   \
     .next_p = NULL                                                     \
   };                                                                   \
                                                                        \
@@ -91,21 +91,42 @@ void jerryx_native_module_register (jerryx_native_module_t *module_p);
  */
 void jerryx_native_module_unregister (jerryx_native_module_t *module_p);
 
+/**
+ * Declare the function pointer type for canonical name resolution.
+ */
+typedef jerry_value_t (*jerryx_module_get_canonical_name_t) (const jerry_value_t name); /**< The name for which to
+                                                                                         *   compute the canonical
+                                                                                         *   name */
+
+/**
+ * Declare the function pointer type for module resolution.
+ */
+typedef bool (*jerryx_module_resolve_t) (const jerry_value_t canonical_name, /**< The module's canonical name */
+                                         jerry_value_t *result); /**< The resulting module, if the function returns
+                                                                  *   true */
+
+/**
+ * Declare the structure for module resolvers.
+ */
+typedef struct
+{
+  jerryx_module_get_canonical_name_t get_canonical_name_p; /**< function pointer to establish the canonical name of a
+                                                            *   module */
+  jerryx_module_resolve_t resolve_p; /**< function pointer to resolve a module */
+} jerryx_module_resolver_t;
+
 /**
  * Declare the JerryScript module resolver so that it may be added to an array of jerryx_module_resolver_t items and
  * thus passed to jerryx_module_resolve.
  */
-bool jerryx_module_native_resolver (const jerry_char_t *name, jerry_value_t *result);
-
-/**
- * Declare the function pointer type for module resolvers.
- */
-typedef bool (*jerryx_module_resolver_t) (const jerry_char_t *name, jerry_value_t *result);
+extern jerryx_module_resolver_t jerryx_module_native_resolver;
 
 /**
  * Load a copy of a module into the current context using the provided module resolvers, or return one that was already
  * loaded if it is found.
  */
-jerry_value_t jerryx_module_resolve (const jerry_char_t *name, const jerryx_module_resolver_t *resolvers, size_t count);
+jerry_value_t jerryx_module_resolve (const jerry_value_t name,
+                                     const jerryx_module_resolver_t **resolvers,
+                                     size_t count);
 
 #endif /* !JERRYX_MODULE_H */