1/*
2 * This file is part of the MicroPython project, http://micropython.org/
3 *
4 * The MIT License (MIT)
5 *
6 * Copyright (c) 2013-2019 Damien P. George
7 * Copyright (c) 2014 Paul Sokolovsky
8 *
9 * Permission is hereby granted, free of charge, to any person obtaining a copy
10 * of this software and associated documentation files (the "Software"), to deal
11 * in the Software without restriction, including without limitation the rights
12 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
13 * copies of the Software, and to permit persons to whom the Software is
14 * furnished to do so, subject to the following conditions:
15 *
16 * The above copyright notice and this permission notice shall be included in
17 * all copies or substantial portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
22 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
24 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25 * THE SOFTWARE.
26 */
27
28#include <stdio.h>
29#include <string.h>
30#include <assert.h>
31
32#include "py/compile.h"
33#include "py/objmodule.h"
34#include "py/persistentcode.h"
35#include "py/runtime.h"
36#include "py/builtin.h"
37#include "py/frozenmod.h"
38
39#if MICROPY_DEBUG_VERBOSE // print debugging info
40#define DEBUG_PRINT (1)
41#define DEBUG_printf DEBUG_printf
42#else // don't print debugging info
43#define DEBUG_PRINT (0)
44#define DEBUG_printf(...) (void)0
45#endif
46
47#if MICROPY_ENABLE_EXTERNAL_IMPORT
48
49#define PATH_SEP_CHAR '/'
50
51bool mp_obj_is_package(mp_obj_t module) {
52 mp_obj_t dest[2];
53 mp_load_method_maybe(module, MP_QSTR___path__, dest);
54 return dest[0] != MP_OBJ_NULL;
55}
56
57// Stat either frozen or normal module by a given path
58// (whatever is available, if at all).
59STATIC mp_import_stat_t mp_import_stat_any(const char *path) {
60 #if MICROPY_MODULE_FROZEN
61 mp_import_stat_t st = mp_frozen_stat(path);
62 if (st != MP_IMPORT_STAT_NO_EXIST) {
63 return st;
64 }
65 #endif
66 return mp_import_stat(path);
67}
68
69STATIC mp_import_stat_t stat_file_py_or_mpy(vstr_t *path) {
70 mp_import_stat_t stat = mp_import_stat_any(vstr_null_terminated_str(path));
71 if (stat == MP_IMPORT_STAT_FILE) {
72 return stat;
73 }
74
75 #if MICROPY_PERSISTENT_CODE_LOAD
76 vstr_ins_byte(path, path->len - 2, 'm');
77 stat = mp_import_stat_any(vstr_null_terminated_str(path));
78 if (stat == MP_IMPORT_STAT_FILE) {
79 return stat;
80 }
81 #endif
82
83 return MP_IMPORT_STAT_NO_EXIST;
84}
85
86STATIC mp_import_stat_t stat_dir_or_file(vstr_t *path) {
87 mp_import_stat_t stat = mp_import_stat_any(vstr_null_terminated_str(path));
88 DEBUG_printf("stat %s: %d\n", vstr_str(path), stat);
89 if (stat == MP_IMPORT_STAT_DIR) {
90 return stat;
91 }
92
93 // not a directory, add .py and try as a file
94 vstr_add_str(path, ".py");
95 return stat_file_py_or_mpy(path);
96}
97
98STATIC mp_import_stat_t find_file(const char *file_str, uint file_len, vstr_t *dest) {
99 #if MICROPY_PY_SYS
100 // extract the list of paths
101 size_t path_num;
102 mp_obj_t *path_items;
103 mp_obj_list_get(mp_sys_path, &path_num, &path_items);
104
105 if (path_num != 0) {
106 // go through each path looking for a directory or file
107 for (size_t i = 0; i < path_num; i++) {
108 vstr_reset(dest);
109 size_t p_len;
110 const char *p = mp_obj_str_get_data(path_items[i], &p_len);
111 if (p_len > 0) {
112 vstr_add_strn(dest, p, p_len);
113 vstr_add_char(dest, PATH_SEP_CHAR);
114 }
115 vstr_add_strn(dest, file_str, file_len);
116 mp_import_stat_t stat = stat_dir_or_file(dest);
117 if (stat != MP_IMPORT_STAT_NO_EXIST) {
118 return stat;
119 }
120 }
121
122 // could not find a directory or file
123 return MP_IMPORT_STAT_NO_EXIST;
124 }
125 #endif
126
127 // mp_sys_path is empty, so just use the given file name
128 vstr_add_strn(dest, file_str, file_len);
129 return stat_dir_or_file(dest);
130}
131
132#if MICROPY_MODULE_FROZEN_STR || MICROPY_ENABLE_COMPILER
133STATIC void do_load_from_lexer(mp_obj_t module_obj, mp_lexer_t *lex) {
134 #if MICROPY_PY___FILE__
135 qstr source_name = lex->source_name;
136 mp_store_attr(module_obj, MP_QSTR___file__, MP_OBJ_NEW_QSTR(source_name));
137 #endif
138
139 // parse, compile and execute the module in its context
140 mp_obj_dict_t *mod_globals = mp_obj_module_get_globals(module_obj);
141 mp_parse_compile_execute(lex, MP_PARSE_FILE_INPUT, mod_globals, mod_globals);
142}
143#endif
144
145#if MICROPY_PERSISTENT_CODE_LOAD || MICROPY_MODULE_FROZEN_MPY
146STATIC void do_execute_raw_code(mp_obj_t module_obj, mp_raw_code_t *raw_code, const char *source_name) {
147 (void)source_name;
148
149 #if MICROPY_PY___FILE__
150 mp_store_attr(module_obj, MP_QSTR___file__, MP_OBJ_NEW_QSTR(qstr_from_str(source_name)));
151 #endif
152
153 // execute the module in its context
154 mp_obj_dict_t *mod_globals = mp_obj_module_get_globals(module_obj);
155
156 // save context
157 mp_obj_dict_t *volatile old_globals = mp_globals_get();
158 mp_obj_dict_t *volatile old_locals = mp_locals_get();
159
160 // set new context
161 mp_globals_set(mod_globals);
162 mp_locals_set(mod_globals);
163
164 nlr_buf_t nlr;
165 if (nlr_push(&nlr) == 0) {
166 mp_obj_t module_fun = mp_make_function_from_raw_code(raw_code, MP_OBJ_NULL, MP_OBJ_NULL);
167 mp_call_function_0(module_fun);
168
169 // finish nlr block, restore context
170 nlr_pop();
171 mp_globals_set(old_globals);
172 mp_locals_set(old_locals);
173 } else {
174 // exception; restore context and re-raise same exception
175 mp_globals_set(old_globals);
176 mp_locals_set(old_locals);
177 nlr_jump(nlr.ret_val);
178 }
179}
180#endif
181
182STATIC void do_load(mp_obj_t module_obj, vstr_t *file) {
183 #if MICROPY_MODULE_FROZEN || MICROPY_ENABLE_COMPILER || (MICROPY_PERSISTENT_CODE_LOAD && MICROPY_HAS_FILE_READER)
184 char *file_str = vstr_null_terminated_str(file);
185 #endif
186
187 // If we support frozen modules (either as str or mpy) then try to find the
188 // requested filename in the list of frozen module filenames.
189 #if MICROPY_MODULE_FROZEN
190 void *modref;
191 int frozen_type = mp_find_frozen_module(file_str, file->len, &modref);
192 #endif
193
194 // If we support frozen str modules and the compiler is enabled, and we
195 // found the filename in the list of frozen files, then load and execute it.
196 #if MICROPY_MODULE_FROZEN_STR
197 if (frozen_type == MP_FROZEN_STR) {
198 do_load_from_lexer(module_obj, modref);
199 return;
200 }
201 #endif
202
203 // If we support frozen mpy modules and we found a corresponding file (and
204 // its data) in the list of frozen files, execute it.
205 #if MICROPY_MODULE_FROZEN_MPY
206 if (frozen_type == MP_FROZEN_MPY) {
207 do_execute_raw_code(module_obj, modref, file_str);
208 return;
209 }
210 #endif
211
212 // If we support loading .mpy files then check if the file extension is of
213 // the correct format and, if so, load and execute the file.
214 #if MICROPY_HAS_FILE_READER && MICROPY_PERSISTENT_CODE_LOAD
215 if (file_str[file->len - 3] == 'm') {
216 mp_raw_code_t *raw_code = mp_raw_code_load_file(file_str);
217 do_execute_raw_code(module_obj, raw_code, file_str);
218 return;
219 }
220 #endif
221
222 // If we can compile scripts then load the file and compile and execute it.
223 #if MICROPY_ENABLE_COMPILER
224 {
225 mp_lexer_t *lex = mp_lexer_new_from_file(file_str);
226 do_load_from_lexer(module_obj, lex);
227 return;
228 }
229 #else
230 // If we get here then the file was not frozen and we can't compile scripts.
231 mp_raise_msg(&mp_type_ImportError, MP_ERROR_TEXT("script compilation not supported"));
232 #endif
233}
234
235STATIC void chop_component(const char *start, const char **end) {
236 const char *p = *end;
237 while (p > start) {
238 if (*--p == '.') {
239 *end = p;
240 return;
241 }
242 }
243 *end = p;
244}
245
246mp_obj_t mp_builtin___import__(size_t n_args, const mp_obj_t *args) {
247 #if DEBUG_PRINT
248 DEBUG_printf("__import__:\n");
249 for (size_t i = 0; i < n_args; i++) {
250 DEBUG_printf(" ");
251 mp_obj_print(args[i], PRINT_REPR);
252 DEBUG_printf("\n");
253 }
254 #endif
255
256 mp_obj_t module_name = args[0];
257 mp_obj_t fromtuple = mp_const_none;
258 mp_int_t level = 0;
259 if (n_args >= 4) {
260 fromtuple = args[3];
261 if (n_args >= 5) {
262 level = MP_OBJ_SMALL_INT_VALUE(args[4]);
263 if (level < 0) {
264 mp_raise_ValueError(NULL);
265 }
266 }
267 }
268
269 size_t mod_len;
270 const char *mod_str = mp_obj_str_get_data(module_name, &mod_len);
271
272 if (level != 0) {
273 // What we want to do here is to take name of current module,
274 // chop <level> trailing components, and concatenate with passed-in
275 // module name, thus resolving relative import name into absolute.
276 // This even appears to be correct per
277 // http://legacy.python.org/dev/peps/pep-0328/#relative-imports-and-name
278 // "Relative imports use a module's __name__ attribute to determine that
279 // module's position in the package hierarchy."
280 level--;
281 mp_obj_t this_name_q = mp_obj_dict_get(MP_OBJ_FROM_PTR(mp_globals_get()), MP_OBJ_NEW_QSTR(MP_QSTR___name__));
282 assert(this_name_q != MP_OBJ_NULL);
283 #if MICROPY_CPYTHON_COMPAT
284 if (MP_OBJ_QSTR_VALUE(this_name_q) == MP_QSTR___main__) {
285 // This is a module run by -m command-line switch, get its real name from backup attribute
286 this_name_q = mp_obj_dict_get(MP_OBJ_FROM_PTR(mp_globals_get()), MP_OBJ_NEW_QSTR(MP_QSTR___main__));
287 }
288 #endif
289 mp_map_t *globals_map = &mp_globals_get()->map;
290 mp_map_elem_t *elem = mp_map_lookup(globals_map, MP_OBJ_NEW_QSTR(MP_QSTR___path__), MP_MAP_LOOKUP);
291 bool is_pkg = (elem != NULL);
292
293 #if DEBUG_PRINT
294 DEBUG_printf("Current module/package: ");
295 mp_obj_print(this_name_q, PRINT_REPR);
296 DEBUG_printf(", is_package: %d", is_pkg);
297 DEBUG_printf("\n");
298 #endif
299
300 size_t this_name_l;
301 const char *this_name = mp_obj_str_get_data(this_name_q, &this_name_l);
302
303 const char *p = this_name + this_name_l;
304 if (!is_pkg) {
305 // We have module, but relative imports are anchored at package, so
306 // go there.
307 chop_component(this_name, &p);
308 }
309
310 while (level--) {
311 chop_component(this_name, &p);
312 }
313
314 // We must have some component left over to import from
315 if (p == this_name) {
316 mp_raise_ValueError(MP_ERROR_TEXT("can't perform relative import"));
317 }
318
319 uint new_mod_l = (mod_len == 0 ? (size_t)(p - this_name) : (size_t)(p - this_name) + 1 + mod_len);
320 char *new_mod = mp_local_alloc(new_mod_l);
321 memcpy(new_mod, this_name, p - this_name);
322 if (mod_len != 0) {
323 new_mod[p - this_name] = '.';
324 memcpy(new_mod + (p - this_name) + 1, mod_str, mod_len);
325 }
326
327 qstr new_mod_q = qstr_from_strn(new_mod, new_mod_l);
328 mp_local_free(new_mod);
329 DEBUG_printf("Resolved base name for relative import: '%s'\n", qstr_str(new_mod_q));
330 module_name = MP_OBJ_NEW_QSTR(new_mod_q);
331 mod_str = qstr_str(new_mod_q);
332 mod_len = new_mod_l;
333 }
334
335 if (mod_len == 0) {
336 mp_raise_ValueError(NULL);
337 }
338
339 // check if module already exists
340 qstr module_name_qstr = mp_obj_str_get_qstr(module_name);
341 mp_obj_t module_obj = mp_module_get(module_name_qstr);
342 if (module_obj != MP_OBJ_NULL) {
343 DEBUG_printf("Module already loaded\n");
344 // If it's not a package, return module right away
345 char *p = strchr(mod_str, '.');
346 if (p == NULL) {
347 return module_obj;
348 }
349 // If fromlist is not empty, return leaf module
350 if (fromtuple != mp_const_none) {
351 return module_obj;
352 }
353 // Otherwise, we need to return top-level package
354 qstr pkg_name = qstr_from_strn(mod_str, p - mod_str);
355 return mp_module_get(pkg_name);
356 }
357 DEBUG_printf("Module not yet loaded\n");
358
359 uint last = 0;
360 VSTR_FIXED(path, MICROPY_ALLOC_PATH_MAX)
361 module_obj = MP_OBJ_NULL;
362 mp_obj_t top_module_obj = MP_OBJ_NULL;
363 mp_obj_t outer_module_obj = MP_OBJ_NULL;
364 uint i;
365 for (i = 1; i <= mod_len; i++) {
366 if (i == mod_len || mod_str[i] == '.') {
367 // create a qstr for the module name up to this depth
368 qstr mod_name = qstr_from_strn(mod_str, i);
369 DEBUG_printf("Processing module: %s\n", qstr_str(mod_name));
370 DEBUG_printf("Previous path: =%.*s=\n", vstr_len(&path), vstr_str(&path));
371
372 // find the file corresponding to the module name
373 mp_import_stat_t stat;
374 if (vstr_len(&path) == 0) {
375 // first module in the dotted-name; search for a directory or file
376 stat = find_file(mod_str, i, &path);
377 } else {
378 // latter module in the dotted-name; append to path
379 vstr_add_char(&path, PATH_SEP_CHAR);
380 vstr_add_strn(&path, mod_str + last, i - last);
381 stat = stat_dir_or_file(&path);
382 }
383 DEBUG_printf("Current path: %.*s\n", vstr_len(&path), vstr_str(&path));
384
385 if (stat == MP_IMPORT_STAT_NO_EXIST) {
386 module_obj = MP_OBJ_NULL;
387 #if MICROPY_MODULE_WEAK_LINKS
388 // check if there is a weak link to this module
389 if (i == mod_len) {
390 module_obj = mp_module_search_umodule(mod_str);
391 if (module_obj != MP_OBJ_NULL) {
392 // found weak linked module
393 mp_module_call_init(mod_name, module_obj);
394 }
395 }
396 #endif
397 if (module_obj == MP_OBJ_NULL) {
398 // couldn't find the file, so fail
399 #if MICROPY_ERROR_REPORTING == MICROPY_ERROR_REPORTING_TERSE
400 mp_raise_msg(&mp_type_ImportError, MP_ERROR_TEXT("module not found"));
401 #else
402 mp_raise_msg_varg(&mp_type_ImportError, MP_ERROR_TEXT("no module named '%q'"), mod_name);
403 #endif
404 }
405 } else {
406 // found the file, so get the module
407 module_obj = mp_module_get(mod_name);
408 }
409
410 if (module_obj == MP_OBJ_NULL) {
411 // module not already loaded, so load it!
412
413 module_obj = mp_obj_new_module(mod_name);
414
415 // if args[3] (fromtuple) has magic value False, set up
416 // this module for command-line "-m" option (set module's
417 // name to __main__ instead of real name). Do this only
418 // for *modules* however - packages never have their names
419 // replaced, instead they're -m'ed using a special __main__
420 // submodule in them. (This all apparently is done to not
421 // touch package name itself, which is important for future
422 // imports).
423 if (i == mod_len && fromtuple == mp_const_false && stat != MP_IMPORT_STAT_DIR) {
424 mp_obj_module_t *o = MP_OBJ_TO_PTR(module_obj);
425 mp_obj_dict_store(MP_OBJ_FROM_PTR(o->globals), MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR___main__));
426 #if MICROPY_CPYTHON_COMPAT
427 // Store module as "__main__" in the dictionary of loaded modules (returned by sys.modules).
428 mp_obj_dict_store(MP_OBJ_FROM_PTR(&MP_STATE_VM(mp_loaded_modules_dict)), MP_OBJ_NEW_QSTR(MP_QSTR___main__), module_obj);
429 // Store real name in "__main__" attribute. Chosen semi-randonly, to reuse existing qstr's.
430 mp_obj_dict_store(MP_OBJ_FROM_PTR(o->globals), MP_OBJ_NEW_QSTR(MP_QSTR___main__), MP_OBJ_NEW_QSTR(mod_name));
431 #endif
432 }
433
434 if (stat == MP_IMPORT_STAT_DIR) {
435 DEBUG_printf("%.*s is dir\n", vstr_len(&path), vstr_str(&path));
436 // https://docs.python.org/3/reference/import.html
437 // "Specifically, any module that contains a __path__ attribute is considered a package."
438 mp_store_attr(module_obj, MP_QSTR___path__, mp_obj_new_str(vstr_str(&path), vstr_len(&path)));
439 size_t orig_path_len = path.len;
440 vstr_add_char(&path, PATH_SEP_CHAR);
441 vstr_add_str(&path, "__init__.py");
442 if (stat_file_py_or_mpy(&path) != MP_IMPORT_STAT_FILE) {
443 // mp_warning("%s is imported as namespace package", vstr_str(&path));
444 } else {
445 do_load(module_obj, &path);
446 }
447 path.len = orig_path_len;
448 } else { // MP_IMPORT_STAT_FILE
449 do_load(module_obj, &path);
450 // This should be the last component in the import path. If there are
451 // remaining components then it's an ImportError because the current path
452 // (the module that was just loaded) is not a package. This will be caught
453 // on the next iteration because the file will not exist.
454 }
455 }
456 if (outer_module_obj != MP_OBJ_NULL) {
457 qstr s = qstr_from_strn(mod_str + last, i - last);
458 mp_store_attr(outer_module_obj, s, module_obj);
459 }
460 outer_module_obj = module_obj;
461 if (top_module_obj == MP_OBJ_NULL) {
462 top_module_obj = module_obj;
463 }
464 last = i + 1;
465 }
466 }
467
468 // If fromlist is not empty, return leaf module
469 if (fromtuple != mp_const_none) {
470 return module_obj;
471 }
472 // Otherwise, we need to return top-level package
473 return top_module_obj;
474}
475
476#else // MICROPY_ENABLE_EXTERNAL_IMPORT
477
478mp_obj_t mp_builtin___import__(size_t n_args, const mp_obj_t *args) {
479 // Check that it's not a relative import
480 if (n_args >= 5 && MP_OBJ_SMALL_INT_VALUE(args[4]) != 0) {
481 mp_raise_NotImplementedError(MP_ERROR_TEXT("relative import"));
482 }
483
484 // Check if module already exists, and return it if it does
485 qstr module_name_qstr = mp_obj_str_get_qstr(args[0]);
486 mp_obj_t module_obj = mp_module_get(module_name_qstr);
487 if (module_obj != MP_OBJ_NULL) {
488 return module_obj;
489 }
490
491 #if MICROPY_MODULE_WEAK_LINKS
492 // Check if there is a weak link to this module
493 module_obj = mp_module_search_umodule(qstr_str(module_name_qstr));
494 if (module_obj != MP_OBJ_NULL) {
495 // Found weak-linked module
496 mp_module_call_init(module_name_qstr, module_obj);
497 return module_obj;
498 }
499 #endif
500
501 // Couldn't find the module, so fail
502 #if MICROPY_ERROR_REPORTING == MICROPY_ERROR_REPORTING_TERSE
503 mp_raise_msg(&mp_type_ImportError, MP_ERROR_TEXT("module not found"));
504 #else
505 mp_raise_msg_varg(&mp_type_ImportError, MP_ERROR_TEXT("no module named '%q'"), module_name_qstr);
506 #endif
507}
508
509#endif // MICROPY_ENABLE_EXTERNAL_IMPORT
510
511MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_builtin___import___obj, 1, 5, mp_builtin___import__);
512