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builtinimport.c 15.02 KiB
/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
* Copyright (c) 2014 Paul Sokolovsky
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include "py/nlr.h"
#include "py/compile.h"
#include "py/objmodule.h"
#include "py/runtime.h"
#include "py/builtin.h"
#include "py/frozenmod.h"
#if 0 // print debugging info
#define DEBUG_PRINT (1)
#define DEBUG_printf DEBUG_printf
#else // don't print debugging info
#define DEBUG_PRINT (0)
#define DEBUG_printf(...) (void)0
#endif
#define PATH_SEP_CHAR '/'
#if MICROPY_MODULE_WEAK_LINKS
STATIC const mp_map_elem_t mp_builtin_module_weak_links_table[] = {
MICROPY_PORT_BUILTIN_MODULE_WEAK_LINKS
};
STATIC MP_DEFINE_CONST_MAP(mp_builtin_module_weak_links_map, mp_builtin_module_weak_links_table);
#endif
bool mp_obj_is_package(mp_obj_t module) {
mp_obj_t dest[2];
mp_load_method_maybe(module, MP_QSTR___path__, dest);
return dest[0] != MP_OBJ_NULL;
}
STATIC mp_import_stat_t stat_dir_or_file(vstr_t *path) {
mp_import_stat_t stat = mp_import_stat(vstr_null_terminated_str(path));
DEBUG_printf("stat %s: %d\n", vstr_str(path), stat);
if (stat == MP_IMPORT_STAT_DIR) {
return stat;
}
vstr_add_str(path, ".py");
stat = mp_import_stat(vstr_null_terminated_str(path)); if (stat == MP_IMPORT_STAT_FILE) {
return stat;
}
return MP_IMPORT_STAT_NO_EXIST;
}
STATIC mp_import_stat_t find_file(const char *file_str, uint file_len, vstr_t *dest) {
#if MICROPY_PY_SYS
// extract the list of paths
mp_uint_t path_num;
mp_obj_t *path_items;
mp_obj_list_get(mp_sys_path, &path_num, &path_items);
if (path_num == 0) {
#endif
// mp_sys_path is empty, so just use the given file name
vstr_add_strn(dest, file_str, file_len);
return stat_dir_or_file(dest);
#if MICROPY_PY_SYS
} else {
// go through each path looking for a directory or file
for (mp_uint_t i = 0; i < path_num; i++) {
vstr_reset(dest);
mp_uint_t p_len;
const char *p = mp_obj_str_get_data(path_items[i], &p_len);
if (p_len > 0) {
vstr_add_strn(dest, p, p_len);
vstr_add_char(dest, PATH_SEP_CHAR);
}
vstr_add_strn(dest, file_str, file_len);
mp_import_stat_t stat = stat_dir_or_file(dest);
if (stat != MP_IMPORT_STAT_NO_EXIST) {
return stat;
}
}
// could not find a directory or file
return MP_IMPORT_STAT_NO_EXIST;
}
#endif
}
STATIC void do_load_from_lexer(mp_obj_t module_obj, mp_lexer_t *lex, const char *fname) {
if (lex == NULL) {
// we verified the file exists using stat, but lexer could still fail
if (MICROPY_ERROR_REPORTING == MICROPY_ERROR_REPORTING_TERSE) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_ImportError, "module not found"));
} else {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ImportError,
"no module named '%s'", fname));
}
}
#if MICROPY_PY___FILE__
qstr source_name = lex->source_name;
mp_store_attr(module_obj, MP_QSTR___file__, MP_OBJ_NEW_QSTR(source_name));
#endif
// parse, compile and execute the module in its context
mp_obj_dict_t *mod_globals = mp_obj_module_get_globals(module_obj);
mp_parse_compile_execute(lex, MP_PARSE_FILE_INPUT, mod_globals, mod_globals);
}
STATIC void do_load(mp_obj_t module_obj, vstr_t *file) {
// create the lexer
char *file_str = vstr_null_terminated_str(file);
mp_lexer_t *lex = mp_lexer_new_from_file(file_str);
do_load_from_lexer(module_obj, lex, file_str);
}
STATIC void chop_component(const char *start, const char **end) {
const char *p = *end;
while (p > start) {
if (*--p == '.') {
*end = p;
return;
}
}
*end = p;
}
mp_obj_t mp_builtin___import__(mp_uint_t n_args, const mp_obj_t *args) {
#if DEBUG_PRINT
DEBUG_printf("__import__:\n");
for (mp_uint_t i = 0; i < n_args; i++) {
DEBUG_printf(" ");
mp_obj_print(args[i], PRINT_REPR);
DEBUG_printf("\n");
}
#endif
mp_obj_t module_name = args[0];
mp_obj_t fromtuple = mp_const_none;
mp_int_t level = 0;
if (n_args >= 4) {
fromtuple = args[3];
if (n_args >= 5) {
level = MP_OBJ_SMALL_INT_VALUE(args[4]);
}
}
mp_uint_t mod_len;
const char *mod_str = mp_obj_str_get_data(module_name, &mod_len);
if (level != 0) {
// What we want to do here is to take name of current module,
// chop <level> trailing components, and concatenate with passed-in
// module name, thus resolving relative import name into absolue.
// This even appears to be correct per
// http://legacy.python.org/dev/peps/pep-0328/#relative-imports-and-name
// "Relative imports use a module's __name__ attribute to determine that
// module's position in the package hierarchy."
level--;
mp_obj_t this_name_q = mp_obj_dict_get(mp_globals_get(), MP_OBJ_NEW_QSTR(MP_QSTR___name__));
assert(this_name_q != MP_OBJ_NULL);
mp_map_t *globals_map = mp_obj_dict_get_map(mp_globals_get());
mp_map_elem_t *elem = mp_map_lookup(globals_map, MP_OBJ_NEW_QSTR(MP_QSTR___path__), MP_MAP_LOOKUP);
bool is_pkg = (elem != NULL);
#if DEBUG_PRINT
DEBUG_printf("Current module/package: ");
mp_obj_print(this_name_q, PRINT_REPR);
DEBUG_printf(", is_package: %d", is_pkg);
DEBUG_printf("\n");
#endif
mp_uint_t this_name_l;
const char *this_name = mp_obj_str_get_data(this_name_q, &this_name_l);
const char *p = this_name + this_name_l;
if (!is_pkg) {
// We have module, but relative imports are anchored at package, so
// go there.
chop_component(this_name, &p);
}
uint dots_seen = 0;
while (level--) { chop_component(this_name, &p);
dots_seen++;
}
if (dots_seen == 0 && level >= 1) {
// http://legacy.python.org/dev/peps/pep-0328/#relative-imports-and-name
// "If the module's name does not contain any package information
// (e.g. it is set to '__main__') then relative imports are
// resolved as if the module were a top level module, regardless
// of where the module is actually located on the file system."
// Supposedly this if catches this condition and resolve it properly
// TODO: But nobody knows for sure. This condition happens when
// package's __init__.py does something like "import .submod". So,
// maybe we should check for package here? But quote above doesn't
// talk about packages, it talks about dot-less module names.
DEBUG_printf("Warning: no dots in current module name and level>0\n");
p = this_name + this_name_l;
} else if (level != -1) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_ImportError, "Invalid relative import"));
}
uint new_mod_l = (mod_len == 0 ? (size_t)(p - this_name) : (size_t)(p - this_name) + 1 + mod_len);
char *new_mod = alloca(new_mod_l);
memcpy(new_mod, this_name, p - this_name);
if (mod_len != 0) {
new_mod[p - this_name] = '.';
memcpy(new_mod + (p - this_name) + 1, mod_str, mod_len);
}
qstr new_mod_q = qstr_from_strn(new_mod, new_mod_l);
DEBUG_printf("Resolved relative name: %s\n", qstr_str(new_mod_q));
module_name = MP_OBJ_NEW_QSTR(new_mod_q);
mod_str = new_mod;
mod_len = new_mod_l;
}
// check if module already exists
qstr module_name_qstr = mp_obj_str_get_qstr(module_name);
mp_obj_t module_obj = mp_module_get(module_name_qstr);
if (module_obj != MP_OBJ_NULL) {
DEBUG_printf("Module already loaded\n");
// If it's not a package, return module right away
char *p = strchr(mod_str, '.');
if (p == NULL) {
return module_obj;
}
// If fromlist is not empty, return leaf module
if (fromtuple != mp_const_none) {
return module_obj;
}
// Otherwise, we need to return top-level package
qstr pkg_name = qstr_from_strn(mod_str, p - mod_str);
return mp_module_get(pkg_name);
}
DEBUG_printf("Module not yet loaded\n");
#if MICROPY_MODULE_FROZEN
mp_lexer_t *lex = mp_find_frozen_module(mod_str, mod_len);
if (lex != NULL) {
module_obj = mp_obj_new_module(module_name_qstr);
do_load_from_lexer(module_obj, lex, mod_str);
return module_obj;
}
#endif
uint last = 0;
VSTR_FIXED(path, MICROPY_ALLOC_PATH_MAX)
module_obj = MP_OBJ_NULL;
mp_obj_t top_module_obj = MP_OBJ_NULL;
mp_obj_t outer_module_obj = MP_OBJ_NULL; uint i;
for (i = 1; i <= mod_len; i++) {
if (i == mod_len || mod_str[i] == '.') {
// create a qstr for the module name up to this depth
qstr mod_name = qstr_from_strn(mod_str, i);
DEBUG_printf("Processing module: %s\n", qstr_str(mod_name));
DEBUG_printf("Previous path: =%.*s=\n", vstr_len(&path), vstr_str(&path));
// find the file corresponding to the module name
mp_import_stat_t stat;
if (vstr_len(&path) == 0) {
// first module in the dotted-name; search for a directory or file
stat = find_file(mod_str, i, &path);
} else {
// latter module in the dotted-name; append to path
vstr_add_char(&path, PATH_SEP_CHAR);
vstr_add_strn(&path, mod_str + last, i - last);
stat = stat_dir_or_file(&path);
}
DEBUG_printf("Current path: %.*s\n", vstr_len(&path), vstr_str(&path));
if (stat == MP_IMPORT_STAT_NO_EXIST) {
#if MICROPY_MODULE_WEAK_LINKS
// check if there is a weak link to this module
if (i == mod_len) {
mp_map_elem_t *el = mp_map_lookup((mp_map_t*)&mp_builtin_module_weak_links_map, MP_OBJ_NEW_QSTR(mod_name), MP_MAP_LOOKUP);
if (el == NULL) {
goto no_exist;
}
// found weak linked module
module_obj = el->value;
} else {
no_exist:
#else
{
#endif
// couldn't find the file, so fail
if (MICROPY_ERROR_REPORTING == MICROPY_ERROR_REPORTING_TERSE) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_ImportError, "module not found"));
} else {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ImportError,
"no module named '%q'", mod_name));
}
}
} else {
// found the file, so get the module
module_obj = mp_module_get(mod_name);
}
if (module_obj == MP_OBJ_NULL) {
// module not already loaded, so load it!
module_obj = mp_obj_new_module(mod_name);
// if args[3] (fromtuple) has magic value False, set up
// this module for command-line "-m" option (set module's
// name to __main__ instead of real name).
if (i == mod_len && fromtuple == mp_const_false) {
mp_obj_module_t *o = module_obj;
mp_obj_dict_store(o->globals, MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR___main__));
}
if (stat == MP_IMPORT_STAT_DIR) {
DEBUG_printf("%.*s is dir\n", vstr_len(&path), vstr_str(&path));
// https://docs.python.org/3/reference/import.html
// "Specifically, any module that contains a __path__ attribute is considered a package."
mp_store_attr(module_obj, MP_QSTR___path__, mp_obj_new_str(vstr_str(&path), vstr_len(&path), false));
vstr_add_char(&path, PATH_SEP_CHAR);
vstr_add_str(&path, "__init__.py");
if (mp_import_stat(vstr_null_terminated_str(&path)) != MP_IMPORT_STAT_FILE) { vstr_cut_tail_bytes(&path, sizeof("/__init__.py") - 1); // cut off /__init__.py
mp_warning("%s is imported as namespace package", vstr_str(&path));
} else {
do_load(module_obj, &path);
vstr_cut_tail_bytes(&path, sizeof("/__init__.py") - 1); // cut off /__init__.py
}
} else { // MP_IMPORT_STAT_FILE
do_load(module_obj, &path);
// TODO: We cannot just break here, at the very least, we must execute
// trailer code below. But otherwise if there're remaining components,
// that would be (??) object path within module, not modules path within FS.
// break;
}
}
if (outer_module_obj != MP_OBJ_NULL) {
qstr s = qstr_from_strn(mod_str + last, i - last);
mp_store_attr(outer_module_obj, s, module_obj);
}
outer_module_obj = module_obj;
if (top_module_obj == MP_OBJ_NULL) {
top_module_obj = module_obj;
}
last = i + 1;
}
}
if (i < mod_len) {
// we loaded a package, now need to load objects from within that package
// TODO
assert(0);
}
// If fromlist is not empty, return leaf module
if (fromtuple != mp_const_none) {
return module_obj;
}
// Otherwise, we need to return top-level package
return top_module_obj;
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_builtin___import___obj, 1, 5, mp_builtin___import__);