micropython/py/builtinimport.c
Paul Sokolovsky d720ab5236 Implement modules as singletons Python semantics.
In Python, importing module several times returns same underlying module
object. This also fixes import statement handling for builtin modules.

There're still issues:
1. CPython exposes set of loaded modules as sys.modules, we may want to
do that either.
2. Builtin modules are implicitly imported, which is not really correct.
We should separate registering a (builtin) module and importing a module.
CPython keeps builtin module names in sys.builtin_module_names .
2014-01-20 00:38:39 +02:00

95 lines
2.5 KiB
C

#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <assert.h>
#include "nlr.h"
#include "misc.h"
#include "mpconfig.h"
#include "lexer.h"
#include "lexerunix.h"
#include "parse.h"
#include "obj.h"
#include "compile.h"
#include "runtime0.h"
#include "runtime.h"
#include "map.h"
#include "builtin.h"
mp_obj_t mp_builtin___import__(int n_args, mp_obj_t *args) {
/*
printf("import:\n");
for (int i = 0; i < n; i++) {
printf(" ");
mp_obj_print(args[i]);
printf("\n");
}
*/
qstr mod_name = mp_obj_get_qstr(args[0]);
mp_obj_t loaded = mp_obj_module_get(mod_name);
if (loaded != MP_OBJ_NULL) {
return loaded;
}
// find the file to import
mp_lexer_t *lex = mp_import_open_file(mod_name);
if (lex == NULL) {
// TODO handle lexer error correctly
return mp_const_none;
}
// create a new module object
mp_obj_t module_obj = mp_obj_new_module(mp_obj_get_qstr(args[0]));
// save the old context
mp_map_t *old_locals = rt_locals_get();
mp_map_t *old_globals = rt_globals_get();
// set the new context
rt_locals_set(mp_obj_module_get_globals(module_obj));
rt_globals_set(mp_obj_module_get_globals(module_obj));
// parse the imported script
qstr parse_exc_id;
const char *parse_exc_msg;
mp_parse_node_t pn = mp_parse(lex, MP_PARSE_FILE_INPUT, &parse_exc_id, &parse_exc_msg);
qstr source_name = mp_lexer_source_name(lex);
mp_lexer_free(lex);
if (pn == MP_PARSE_NODE_NULL) {
// parse error; clean up and raise exception
rt_locals_set(old_locals);
rt_globals_set(old_globals);
nlr_jump(mp_obj_new_exception_msg(parse_exc_id, parse_exc_msg));
}
// compile the imported script
mp_obj_t module_fun = mp_compile(pn, source_name, false);
if (module_fun == mp_const_none) {
// TODO handle compile error correctly
rt_locals_set(old_locals);
rt_globals_set(old_globals);
return mp_const_none;
}
// complied successfully, execute it
nlr_buf_t nlr;
if (nlr_push(&nlr) == 0) {
rt_call_function_0(module_fun);
nlr_pop();
} else {
// exception; restore context and re-raise same exception
rt_locals_set(old_locals);
rt_globals_set(old_globals);
nlr_jump(nlr.ret_val);
}
rt_locals_set(old_locals);
rt_globals_set(old_globals);
return module_obj;
}