py: Implement __file__ attribute for modules.

py/builtinimport.c

@@ -120,6 +120,9 @@ STATIC void do_load(mp_obj_t module_obj, vstr_t *file) {
     // set the new context
     mp_locals_set(mp_obj_module_get_globals(module_obj));
     mp_globals_set(mp_obj_module_get_globals(module_obj));
+    #if MICROPY_PY___FILE__
+    mp_store_attr(module_obj, MP_QSTR___file__, mp_obj_new_str(vstr_str(file), vstr_len(file), false));
+    #endif
 
     // parse the imported script
     mp_parse_error_kind_t parse_error_kind;

py/mpconfig.h

@@ -279,6 +279,11 @@ typedef double mp_float_t;
 #define MICROPY_PY_BUILTINS_PROPERTY (1)
 #endif
 
+// Whether to set __file__ for imported modules
+#ifndef MICROPY_PY___FILE__
+#define MICROPY_PY___FILE__ (1)
+#endif
+
 // Whether to provide "array" module. Note that large chunk of the
 // underlying code is shared with "bytearray" builtin type, so to
 // get real savings, it should be disabled too.

py/qstrdefs.h

@@ -43,6 +43,9 @@ Q(__next__)
 Q(__qualname__)
 Q(__path__)
 Q(__repl_print__)
+#if MICROPY_PY___FILE__
+Q(__file__)
+#endif
 
 Q(__bool__)
 Q(__contains__)

tests/import/import_file.py

+import import1b
+print(import1b.__file__)

unix/main.c

@@ -95,6 +95,11 @@ STATIC int execute_from_lexer(mp_lexer_t *lex, mp_parse_input_kind_t input_kind,
     }
 
     qstr source_name = mp_lexer_source_name(lex);
+    #if MICROPY_PY___FILE__
+    if (input_kind == MP_PARSE_FILE_INPUT) {
+        mp_store_global(MP_QSTR___file__, MP_OBJ_NEW_QSTR(source_name));
+    }
+    #endif
     mp_lexer_free(lex);
 
     /*