py: Print imported module's location (__file__) if available.

bare-arm/mpconfigport.h

@@ -17,6 +17,7 @@
 #define MICROPY_PY_BUILTINS_SET     (0)
 #define MICROPY_PY_BUILTINS_SLICE   (0)
 #define MICROPY_PY_BUILTINS_PROPERTY (0)
+#define MICROPY_PY___FILE__         (0)
 #define MICROPY_PY_GC               (0)
 #define MICROPY_PY_ARRAY            (0)
 #define MICROPY_PY_COLLECTIONS      (0)

py/objmodule.c

@@ -40,7 +40,19 @@ STATIC mp_map_t mp_loaded_modules_map; // TODO: expose as sys.modules
 
 STATIC void module_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
     mp_obj_module_t *self = self_in;
-    print(env, "<module '%s' from '-unknown-file-'>", qstr_str(self->name));
+    const char *name = qstr_str(self->name);
+
+#if MICROPY_PY___FILE__
+    // If we store __file__ to imported modules then try to lookup this
+    // symbol to give more information about the module.
+    mp_map_elem_t *elem = mp_map_lookup(&self->globals->map, MP_OBJ_NEW_QSTR(MP_QSTR___file__), MP_MAP_LOOKUP);
+    if (elem != NULL) {
+        print(env, "<module '%s' from '%s'>", name, mp_obj_str_get_str(elem->value));
+        return;
+    }
+#endif
+
+    print(env, "<module '%s'>", name);
 }
 
 STATIC void module_load_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {