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1 
2 /* Module definition and import implementation */
3 
4 #include "Python.h"
5 
6 #include "Python-ast.h"
7 #undef Yield /* undefine macro conflicting with winbase.h */
8 #include "pyarena.h"
9 #include "pythonrun.h"
10 #include "errcode.h"
11 #include "marshal.h"
12 #include "code.h"
13 #include "compile.h"
14 #include "eval.h"
15 #include "osdefs.h"
16 #include "importdl.h"
17 
18 #ifdef HAVE_FCNTL_H
19 #include <fcntl.h>
20 #endif
21 #ifdef __cplusplus
22 extern "C" {
23 #endif
24 
25 #ifdef MS_WINDOWS
26 /* for stat.st_mode */
27 typedef unsigned short mode_t;
28 #endif
29 
30 
31 /* Magic word to reject .pyc files generated by other Python versions.
32    It should change for each incompatible change to the bytecode.
33 
34    The value of CR and LF is incorporated so if you ever read or write
35    a .pyc file in text mode the magic number will be wrong; also, the
36    Apple MPW compiler swaps their values, botching string constants.
37 
38    The magic numbers must be spaced apart atleast 2 values, as the
39    -U interpeter flag will cause MAGIC+1 being used. They have been
40    odd numbers for some time now.
41 
42    There were a variety of old schemes for setting the magic number.
43    The current working scheme is to increment the previous value by
44    10.
45 
46    Known values:
47        Python 1.5:   20121
48        Python 1.5.1: 20121
49        Python 1.5.2: 20121
50        Python 1.6:   50428
51        Python 2.0:   50823
52        Python 2.0.1: 50823
53        Python 2.1:   60202
54        Python 2.1.1: 60202
55        Python 2.1.2: 60202
56        Python 2.2:   60717
57        Python 2.3a0: 62011
58        Python 2.3a0: 62021
59        Python 2.3a0: 62011 (!)
60        Python 2.4a0: 62041
61        Python 2.4a3: 62051
62        Python 2.4b1: 62061
63        Python 2.5a0: 62071
64        Python 2.5a0: 62081 (ast-branch)
65        Python 2.5a0: 62091 (with)
66        Python 2.5a0: 62092 (changed WITH_CLEANUP opcode)
67        Python 2.5b3: 62101 (fix wrong code: for x, in ...)
68        Python 2.5b3: 62111 (fix wrong code: x += yield)
69        Python 2.5c1: 62121 (fix wrong lnotab with for loops and
70                             storing constants that should have been removed)
71        Python 2.5c2: 62131 (fix wrong code: for x, in ... in listcomp/genexp)
72        Python 2.6a0: 62151 (peephole optimizations and STORE_MAP opcode)
73        Python 2.6a1: 62161 (WITH_CLEANUP optimization)
74        Python 2.7a0: 62171 (optimize list comprehensions/change LIST_APPEND)
75        Python 2.7a0: 62181 (optimize conditional branches:
76                 introduce POP_JUMP_IF_FALSE and POP_JUMP_IF_TRUE)
77        Python 2.7a0  62191 (introduce SETUP_WITH)
78        Python 2.7a0  62201 (introduce BUILD_SET)
79        Python 2.7a0  62211 (introduce MAP_ADD and SET_ADD)
80 .
81 */
82 #define MAGIC (62211 | ((long)'\r'<<16) | ((long)'\n'<<24))
83 
84 /* Magic word as global; note that _PyImport_Init() can change the
85    value of this global to accommodate for alterations of how the
86    compiler works which are enabled by command line switches. */
87 static long pyc_magic = MAGIC;
88 
89 /* See _PyImport_FixupExtension() below */
90 static PyObject *extensions = NULL;
91 
92 /* This table is defined in config.c: */
93 extern struct _inittab _PyImport_Inittab[];
94 
95 struct _inittab *PyImport_Inittab = _PyImport_Inittab;
96 
97 /* these tables define the module suffixes that Python recognizes */
98 struct filedescr * _PyImport_Filetab = NULL;
99 
100 #ifdef RISCOS
101 static const struct filedescr _PyImport_StandardFiletab[] = {
102     {"/py", "U", PY_SOURCE},
103     {"/pyc", "rb", PY_COMPILED},
104     {0, 0}
105 };
106 #else
107 static const struct filedescr _PyImport_StandardFiletab[] = {
108     {".py", "U", PY_SOURCE},
109 #ifdef MS_WINDOWS
110     {".pyw", "U", PY_SOURCE},
111 #endif
112     {".pyc", "rb", PY_COMPILED},
113     {0, 0}
114 };
115 #endif
116 
117 #ifdef MS_WINDOWS
isdir(char * path)118 static int isdir(char *path) {
119     DWORD rv;
120     /* see issue1293 and issue3677:
121      * stat() on Windows doesn't recognise paths like
122      * "e:\\shared\\" and "\\\\whiterab-c2znlh\\shared" as dirs.
123      * Also reference issue6727:
124      * stat() on Windows is broken and doesn't resolve symlinks properly.
125      */
126     rv = GetFileAttributesA(path);
127     return rv != INVALID_FILE_ATTRIBUTES && rv & FILE_ATTRIBUTE_DIRECTORY;
128 }
129 #else
130 #ifdef HAVE_STAT
isdir(char * path)131 static int isdir(char *path) {
132     struct stat statbuf;
133     return stat(path, &statbuf) == 0 && S_ISDIR(statbuf.st_mode);
134 }
135 #else
136 #ifdef RISCOS
137 /* with RISCOS, isdir is in unixstuff */
138 #else
isdir(char * path)139 int isdir(char *path) {
140     return 0;
141 }
142 #endif /* RISCOS */
143 #endif /* HAVE_STAT */
144 #endif /* MS_WINDOWS */
145 
146 /* Initialize things */
147 
148 void
_PyImport_Init(void)149 _PyImport_Init(void)
150 {
151     const struct filedescr *scan;
152     struct filedescr *filetab;
153     int countD = 0;
154     int countS = 0;
155 
156     /* prepare _PyImport_Filetab: copy entries from
157        _PyImport_DynLoadFiletab and _PyImport_StandardFiletab.
158      */
159 #ifdef HAVE_DYNAMIC_LOADING
160     for (scan = _PyImport_DynLoadFiletab; scan->suffix != NULL; ++scan)
161         ++countD;
162 #endif
163     for (scan = _PyImport_StandardFiletab; scan->suffix != NULL; ++scan)
164         ++countS;
165     filetab = PyMem_NEW(struct filedescr, countD + countS + 1);
166     if (filetab == NULL)
167         Py_FatalError("Can't initialize import file table.");
168 #ifdef HAVE_DYNAMIC_LOADING
169     memcpy(filetab, _PyImport_DynLoadFiletab,
170            countD * sizeof(struct filedescr));
171 #endif
172     memcpy(filetab + countD, _PyImport_StandardFiletab,
173            countS * sizeof(struct filedescr));
174     filetab[countD + countS].suffix = NULL;
175 
176     _PyImport_Filetab = filetab;
177 
178     if (Py_OptimizeFlag) {
179         /* Replace ".pyc" with ".pyo" in _PyImport_Filetab */
180         for (; filetab->suffix != NULL; filetab++) {
181 #ifndef RISCOS
182             if (strcmp(filetab->suffix, ".pyc") == 0)
183                 filetab->suffix = ".pyo";
184 #else
185             if (strcmp(filetab->suffix, "/pyc") == 0)
186                 filetab->suffix = "/pyo";
187 #endif
188         }
189     }
190 
191     if (Py_UnicodeFlag) {
192         /* Fix the pyc_magic so that byte compiled code created
193            using the all-Unicode method doesn't interfere with
194            code created in normal operation mode. */
195         pyc_magic = MAGIC + 1;
196     }
197 }
198 
199 void
_PyImportHooks_Init(void)200 _PyImportHooks_Init(void)
201 {
202     PyObject *v, *path_hooks = NULL, *zimpimport;
203     int err = 0;
204 
205     /* adding sys.path_hooks and sys.path_importer_cache, setting up
206        zipimport */
207     if (PyType_Ready(&PyNullImporter_Type) < 0)
208         goto error;
209 
210     if (Py_VerboseFlag)
211         PySys_WriteStderr("# installing zipimport hook\n");
212 
213     v = PyList_New(0);
214     if (v == NULL)
215         goto error;
216     err = PySys_SetObject("meta_path", v);
217     Py_DECREF(v);
218     if (err)
219         goto error;
220     v = PyDict_New();
221     if (v == NULL)
222         goto error;
223     err = PySys_SetObject("path_importer_cache", v);
224     Py_DECREF(v);
225     if (err)
226         goto error;
227     path_hooks = PyList_New(0);
228     if (path_hooks == NULL)
229         goto error;
230     err = PySys_SetObject("path_hooks", path_hooks);
231     if (err) {
232   error:
233         PyErr_Print();
234         Py_FatalError("initializing sys.meta_path, sys.path_hooks, "
235                       "path_importer_cache, or NullImporter failed"
236                       );
237     }
238 
239     zimpimport = PyImport_ImportModule("zipimport");
240     if (zimpimport == NULL) {
241         PyErr_Clear(); /* No zip import module -- okay */
242         if (Py_VerboseFlag)
243             PySys_WriteStderr("# can't import zipimport\n");
244     }
245     else {
246         PyObject *zipimporter = PyObject_GetAttrString(zimpimport,
247                                                        "zipimporter");
248         Py_DECREF(zimpimport);
249         if (zipimporter == NULL) {
250             PyErr_Clear(); /* No zipimporter object -- okay */
251             if (Py_VerboseFlag)
252                 PySys_WriteStderr(
253                     "# can't import zipimport.zipimporter\n");
254         }
255         else {
256             /* sys.path_hooks.append(zipimporter) */
257             err = PyList_Append(path_hooks, zipimporter);
258             Py_DECREF(zipimporter);
259             if (err)
260                 goto error;
261             if (Py_VerboseFlag)
262                 PySys_WriteStderr(
263                     "# installed zipimport hook\n");
264         }
265     }
266     Py_DECREF(path_hooks);
267 }
268 
269 void
_PyImport_Fini(void)270 _PyImport_Fini(void)
271 {
272     Py_XDECREF(extensions);
273     extensions = NULL;
274     PyMem_DEL(_PyImport_Filetab);
275     _PyImport_Filetab = NULL;
276 }
277 
278 
279 /* Locking primitives to prevent parallel imports of the same module
280    in different threads to return with a partially loaded module.
281    These calls are serialized by the global interpreter lock. */
282 
283 #ifdef WITH_THREAD
284 
285 #include "pythread.h"
286 
287 static PyThread_type_lock import_lock = 0;
288 static long import_lock_thread = -1;
289 static int import_lock_level = 0;
290 
291 void
_PyImport_AcquireLock(void)292 _PyImport_AcquireLock(void)
293 {
294     long me = PyThread_get_thread_ident();
295     if (me == -1)
296         return; /* Too bad */
297     if (import_lock == NULL) {
298         import_lock = PyThread_allocate_lock();
299         if (import_lock == NULL)
300             return;  /* Nothing much we can do. */
301     }
302     if (import_lock_thread == me) {
303         import_lock_level++;
304         return;
305     }
306     if (import_lock_thread != -1 || !PyThread_acquire_lock(import_lock, 0))
307     {
308         PyThreadState *tstate = PyEval_SaveThread();
309         PyThread_acquire_lock(import_lock, 1);
310         PyEval_RestoreThread(tstate);
311     }
312     import_lock_thread = me;
313     import_lock_level = 1;
314 }
315 
316 int
_PyImport_ReleaseLock(void)317 _PyImport_ReleaseLock(void)
318 {
319     long me = PyThread_get_thread_ident();
320     if (me == -1 || import_lock == NULL)
321         return 0; /* Too bad */
322     if (import_lock_thread != me)
323         return -1;
324     import_lock_level--;
325     if (import_lock_level == 0) {
326         import_lock_thread = -1;
327         PyThread_release_lock(import_lock);
328     }
329     return 1;
330 }
331 
332 /* This function is called from PyOS_AfterFork to ensure that newly
333    created child processes do not share locks with the parent.
334    We now acquire the import lock around fork() calls but on some platforms
335    (Solaris 9 and earlier? see isue7242) that still left us with problems. */
336 
337 void
_PyImport_ReInitLock(void)338 _PyImport_ReInitLock(void)
339 {
340     if (import_lock != NULL) {
341         import_lock = PyThread_allocate_lock();
342         if (import_lock == NULL) {
343             Py_FatalError("PyImport_ReInitLock failed to create a new lock");
344         }
345     }
346     import_lock_thread = -1;
347     import_lock_level = 0;
348 }
349 
350 #endif
351 
352 static PyObject *
imp_lock_held(PyObject * self,PyObject * noargs)353 imp_lock_held(PyObject *self, PyObject *noargs)
354 {
355 #ifdef WITH_THREAD
356     return PyBool_FromLong(import_lock_thread != -1);
357 #else
358     return PyBool_FromLong(0);
359 #endif
360 }
361 
362 static PyObject *
imp_acquire_lock(PyObject * self,PyObject * noargs)363 imp_acquire_lock(PyObject *self, PyObject *noargs)
364 {
365 #ifdef WITH_THREAD
366     _PyImport_AcquireLock();
367 #endif
368     Py_INCREF(Py_None);
369     return Py_None;
370 }
371 
372 static PyObject *
imp_release_lock(PyObject * self,PyObject * noargs)373 imp_release_lock(PyObject *self, PyObject *noargs)
374 {
375 #ifdef WITH_THREAD
376     if (_PyImport_ReleaseLock() < 0) {
377         PyErr_SetString(PyExc_RuntimeError,
378                         "not holding the import lock");
379         return NULL;
380     }
381 #endif
382     Py_INCREF(Py_None);
383     return Py_None;
384 }
385 
386 static void
imp_modules_reloading_clear(void)387 imp_modules_reloading_clear(void)
388 {
389     PyInterpreterState *interp = PyThreadState_Get()->interp;
390     if (interp->modules_reloading != NULL)
391         PyDict_Clear(interp->modules_reloading);
392 }
393 
394 /* Helper for sys */
395 
396 PyObject *
PyImport_GetModuleDict(void)397 PyImport_GetModuleDict(void)
398 {
399     PyInterpreterState *interp = PyThreadState_GET()->interp;
400     if (interp->modules == NULL)
401         Py_FatalError("PyImport_GetModuleDict: no module dictionary!");
402     return interp->modules;
403 }
404 
405 
406 /* List of names to clear in sys */
407 static char* sys_deletes[] = {
408     "path", "argv", "ps1", "ps2", "exitfunc",
409     "exc_type", "exc_value", "exc_traceback",
410     "last_type", "last_value", "last_traceback",
411     "path_hooks", "path_importer_cache", "meta_path",
412     /* misc stuff */
413     "flags", "float_info",
414     NULL
415 };
416 
417 static char* sys_files[] = {
418     "stdin", "__stdin__",
419     "stdout", "__stdout__",
420     "stderr", "__stderr__",
421     NULL
422 };
423 
424 
425 /* Un-initialize things, as good as we can */
426 
427 void
PyImport_Cleanup(void)428 PyImport_Cleanup(void)
429 {
430     Py_ssize_t pos, ndone;
431     char *name;
432     PyObject *key, *value, *dict;
433     PyInterpreterState *interp = PyThreadState_GET()->interp;
434     PyObject *modules = interp->modules;
435 
436     if (modules == NULL)
437         return; /* Already done */
438 
439     /* Delete some special variables first.  These are common
440        places where user values hide and people complain when their
441        destructors fail.  Since the modules containing them are
442        deleted *last* of all, they would come too late in the normal
443        destruction order.  Sigh. */
444 
445     value = PyDict_GetItemString(modules, "__builtin__");
446     if (value != NULL && PyModule_Check(value)) {
447         dict = PyModule_GetDict(value);
448         if (Py_VerboseFlag)
449             PySys_WriteStderr("# clear __builtin__._\n");
450         PyDict_SetItemString(dict, "_", Py_None);
451     }
452     value = PyDict_GetItemString(modules, "sys");
453     if (value != NULL && PyModule_Check(value)) {
454         char **p;
455         PyObject *v;
456         dict = PyModule_GetDict(value);
457         for (p = sys_deletes; *p != NULL; p++) {
458             if (Py_VerboseFlag)
459                 PySys_WriteStderr("# clear sys.%s\n", *p);
460             PyDict_SetItemString(dict, *p, Py_None);
461         }
462         for (p = sys_files; *p != NULL; p+=2) {
463             if (Py_VerboseFlag)
464                 PySys_WriteStderr("# restore sys.%s\n", *p);
465             v = PyDict_GetItemString(dict, *(p+1));
466             if (v == NULL)
467                 v = Py_None;
468             PyDict_SetItemString(dict, *p, v);
469         }
470     }
471 
472     /* First, delete __main__ */
473     value = PyDict_GetItemString(modules, "__main__");
474     if (value != NULL && PyModule_Check(value)) {
475         if (Py_VerboseFlag)
476             PySys_WriteStderr("# cleanup __main__\n");
477         _PyModule_Clear(value);
478         PyDict_SetItemString(modules, "__main__", Py_None);
479     }
480 
481     /* The special treatment of __builtin__ here is because even
482        when it's not referenced as a module, its dictionary is
483        referenced by almost every module's __builtins__.  Since
484        deleting a module clears its dictionary (even if there are
485        references left to it), we need to delete the __builtin__
486        module last.  Likewise, we don't delete sys until the very
487        end because it is implicitly referenced (e.g. by print).
488 
489        Also note that we 'delete' modules by replacing their entry
490        in the modules dict with None, rather than really deleting
491        them; this avoids a rehash of the modules dictionary and
492        also marks them as "non existent" so they won't be
493        re-imported. */
494 
495     /* Next, repeatedly delete modules with a reference count of
496        one (skipping __builtin__ and sys) and delete them */
497     do {
498         ndone = 0;
499         pos = 0;
500         while (PyDict_Next(modules, &pos, &key, &value)) {
501             if (value->ob_refcnt != 1)
502                 continue;
503             if (PyString_Check(key) && PyModule_Check(value)) {
504                 name = PyString_AS_STRING(key);
505                 if (strcmp(name, "__builtin__") == 0)
506                     continue;
507                 if (strcmp(name, "sys") == 0)
508                     continue;
509                 if (Py_VerboseFlag)
510                     PySys_WriteStderr(
511                         "# cleanup[1] %s\n", name);
512                 _PyModule_Clear(value);
513                 PyDict_SetItem(modules, key, Py_None);
514                 ndone++;
515             }
516         }
517     } while (ndone > 0);
518 
519     /* Next, delete all modules (still skipping __builtin__ and sys) */
520     pos = 0;
521     while (PyDict_Next(modules, &pos, &key, &value)) {
522         if (PyString_Check(key) && PyModule_Check(value)) {
523             name = PyString_AS_STRING(key);
524             if (strcmp(name, "__builtin__") == 0)
525                 continue;
526             if (strcmp(name, "sys") == 0)
527                 continue;
528             if (Py_VerboseFlag)
529                 PySys_WriteStderr("# cleanup[2] %s\n", name);
530             _PyModule_Clear(value);
531             PyDict_SetItem(modules, key, Py_None);
532         }
533     }
534 
535     /* Next, delete sys and __builtin__ (in that order) */
536     value = PyDict_GetItemString(modules, "sys");
537     if (value != NULL && PyModule_Check(value)) {
538         if (Py_VerboseFlag)
539             PySys_WriteStderr("# cleanup sys\n");
540         _PyModule_Clear(value);
541         PyDict_SetItemString(modules, "sys", Py_None);
542     }
543     value = PyDict_GetItemString(modules, "__builtin__");
544     if (value != NULL && PyModule_Check(value)) {
545         if (Py_VerboseFlag)
546             PySys_WriteStderr("# cleanup __builtin__\n");
547         _PyModule_Clear(value);
548         PyDict_SetItemString(modules, "__builtin__", Py_None);
549     }
550 
551     /* Finally, clear and delete the modules directory */
552     PyDict_Clear(modules);
553     interp->modules = NULL;
554     Py_DECREF(modules);
555     Py_CLEAR(interp->modules_reloading);
556 }
557 
558 
559 /* Helper for pythonrun.c -- return magic number */
560 
561 long
PyImport_GetMagicNumber(void)562 PyImport_GetMagicNumber(void)
563 {
564     return pyc_magic;
565 }
566 
567 
568 /* Magic for extension modules (built-in as well as dynamically
569    loaded).  To prevent initializing an extension module more than
570    once, we keep a static dictionary 'extensions' keyed by module name
571    (for built-in modules) or by filename (for dynamically loaded
572    modules), containing these modules.  A copy of the module's
573    dictionary is stored by calling _PyImport_FixupExtension()
574    immediately after the module initialization function succeeds.  A
575    copy can be retrieved from there by calling
576    _PyImport_FindExtension(). */
577 
578 PyObject *
_PyImport_FixupExtension(char * name,char * filename)579 _PyImport_FixupExtension(char *name, char *filename)
580 {
581     PyObject *modules, *mod, *dict, *copy;
582     if (extensions == NULL) {
583         extensions = PyDict_New();
584         if (extensions == NULL)
585             return NULL;
586     }
587     modules = PyImport_GetModuleDict();
588     mod = PyDict_GetItemString(modules, name);
589     if (mod == NULL || !PyModule_Check(mod)) {
590         PyErr_Format(PyExc_SystemError,
591           "_PyImport_FixupExtension: module %.200s not loaded", name);
592         return NULL;
593     }
594     dict = PyModule_GetDict(mod);
595     if (dict == NULL)
596         return NULL;
597     copy = PyDict_Copy(dict);
598     if (copy == NULL)
599         return NULL;
600     PyDict_SetItemString(extensions, filename, copy);
601     Py_DECREF(copy);
602     return copy;
603 }
604 
605 PyObject *
_PyImport_FindExtension(char * name,char * filename)606 _PyImport_FindExtension(char *name, char *filename)
607 {
608     PyObject *dict, *mod, *mdict;
609     if (extensions == NULL)
610         return NULL;
611     dict = PyDict_GetItemString(extensions, filename);
612     if (dict == NULL)
613         return NULL;
614     mod = PyImport_AddModule(name);
615     if (mod == NULL)
616         return NULL;
617     mdict = PyModule_GetDict(mod);
618     if (mdict == NULL)
619         return NULL;
620     if (PyDict_Update(mdict, dict))
621         return NULL;
622     if (Py_VerboseFlag)
623         PySys_WriteStderr("import %s # previously loaded (%s)\n",
624             name, filename);
625     return mod;
626 }
627 
628 
629 /* Get the module object corresponding to a module name.
630    First check the modules dictionary if there's one there,
631    if not, create a new one and insert it in the modules dictionary.
632    Because the former action is most common, THIS DOES NOT RETURN A
633    'NEW' REFERENCE! */
634 
635 PyObject *
PyImport_AddModule(const char * name)636 PyImport_AddModule(const char *name)
637 {
638     PyObject *modules = PyImport_GetModuleDict();
639     PyObject *m;
640 
641     if ((m = PyDict_GetItemString(modules, name)) != NULL &&
642         PyModule_Check(m))
643         return m;
644     m = PyModule_New(name);
645     if (m == NULL)
646         return NULL;
647     if (PyDict_SetItemString(modules, name, m) != 0) {
648         Py_DECREF(m);
649         return NULL;
650     }
651     Py_DECREF(m); /* Yes, it still exists, in modules! */
652 
653     return m;
654 }
655 
656 /* Remove name from sys.modules, if it's there. */
657 static void
remove_module(const char * name)658 remove_module(const char *name)
659 {
660     PyObject *modules = PyImport_GetModuleDict();
661     if (PyDict_GetItemString(modules, name) == NULL)
662         return;
663     if (PyDict_DelItemString(modules, name) < 0)
664         Py_FatalError("import:  deleting existing key in"
665                       "sys.modules failed");
666 }
667 
668 /* Execute a code object in a module and return the module object
669  * WITH INCREMENTED REFERENCE COUNT.  If an error occurs, name is
670  * removed from sys.modules, to avoid leaving damaged module objects
671  * in sys.modules.  The caller may wish to restore the original
672  * module object (if any) in this case; PyImport_ReloadModule is an
673  * example.
674  */
675 PyObject *
PyImport_ExecCodeModule(char * name,PyObject * co)676 PyImport_ExecCodeModule(char *name, PyObject *co)
677 {
678     return PyImport_ExecCodeModuleEx(name, co, (char *)NULL);
679 }
680 
681 PyObject *
PyImport_ExecCodeModuleEx(char * name,PyObject * co,char * pathname)682 PyImport_ExecCodeModuleEx(char *name, PyObject *co, char *pathname)
683 {
684     PyObject *modules = PyImport_GetModuleDict();
685     PyObject *m, *d, *v;
686 
687     m = PyImport_AddModule(name);
688     if (m == NULL)
689         return NULL;
690     /* If the module is being reloaded, we get the old module back
691        and re-use its dict to exec the new code. */
692     d = PyModule_GetDict(m);
693     if (PyDict_GetItemString(d, "__builtins__") == NULL) {
694         if (PyDict_SetItemString(d, "__builtins__",
695                                  PyEval_GetBuiltins()) != 0)
696             goto error;
697     }
698     /* Remember the filename as the __file__ attribute */
699     v = NULL;
700     if (pathname != NULL) {
701         v = PyString_FromString(pathname);
702         if (v == NULL)
703             PyErr_Clear();
704     }
705     if (v == NULL) {
706         v = ((PyCodeObject *)co)->co_filename;
707         Py_INCREF(v);
708     }
709     if (PyDict_SetItemString(d, "__file__", v) != 0)
710         PyErr_Clear(); /* Not important enough to report */
711     Py_DECREF(v);
712 
713     v = PyEval_EvalCode((PyCodeObject *)co, d, d);
714     if (v == NULL)
715         goto error;
716     Py_DECREF(v);
717 
718     if ((m = PyDict_GetItemString(modules, name)) == NULL) {
719         PyErr_Format(PyExc_ImportError,
720                      "Loaded module %.200s not found in sys.modules",
721                      name);
722         return NULL;
723     }
724 
725     Py_INCREF(m);
726 
727     return m;
728 
729   error:
730     remove_module(name);
731     return NULL;
732 }
733 
734 
735 /* Given a pathname for a Python source file, fill a buffer with the
736    pathname for the corresponding compiled file.  Return the pathname
737    for the compiled file, or NULL if there's no space in the buffer.
738    Doesn't set an exception. */
739 
740 static char *
make_compiled_pathname(char * pathname,char * buf,size_t buflen)741 make_compiled_pathname(char *pathname, char *buf, size_t buflen)
742 {
743     size_t len = strlen(pathname);
744     if (len+2 > buflen)
745         return NULL;
746 
747 #ifdef MS_WINDOWS
748     /* Treat .pyw as if it were .py.  The case of ".pyw" must match
749        that used in _PyImport_StandardFiletab. */
750     if (len >= 4 && strcmp(&pathname[len-4], ".pyw") == 0)
751         --len;          /* pretend 'w' isn't there */
752 #endif
753     memcpy(buf, pathname, len);
754     buf[len] = Py_OptimizeFlag ? 'o' : 'c';
755     buf[len+1] = '\0';
756 
757     return buf;
758 }
759 
760 
761 /* Given a pathname for a Python source file, its time of last
762    modification, and a pathname for a compiled file, check whether the
763    compiled file represents the same version of the source.  If so,
764    return a FILE pointer for the compiled file, positioned just after
765    the header; if not, return NULL.
766    Doesn't set an exception. */
767 
768 static FILE *
check_compiled_module(char * pathname,time_t mtime,char * cpathname)769 check_compiled_module(char *pathname, time_t mtime, char *cpathname)
770 {
771     FILE *fp;
772     long magic;
773     long pyc_mtime;
774 
775     fp = fopen(cpathname, "rb");
776     if (fp == NULL)
777         return NULL;
778     magic = PyMarshal_ReadLongFromFile(fp);
779     if (magic != pyc_magic) {
780         if (Py_VerboseFlag)
781             PySys_WriteStderr("# %s has bad magic\n", cpathname);
782         fclose(fp);
783         return NULL;
784     }
785     pyc_mtime = PyMarshal_ReadLongFromFile(fp);
786     if (pyc_mtime != mtime) {
787         if (Py_VerboseFlag)
788             PySys_WriteStderr("# %s has bad mtime\n", cpathname);
789         fclose(fp);
790         return NULL;
791     }
792     if (Py_VerboseFlag)
793         PySys_WriteStderr("# %s matches %s\n", cpathname, pathname);
794     return fp;
795 }
796 
797 
798 /* Read a code object from a file and check it for validity */
799 
800 static PyCodeObject *
read_compiled_module(char * cpathname,FILE * fp)801 read_compiled_module(char *cpathname, FILE *fp)
802 {
803     PyObject *co;
804 
805     co = PyMarshal_ReadLastObjectFromFile(fp);
806     if (co == NULL)
807         return NULL;
808     if (!PyCode_Check(co)) {
809         PyErr_Format(PyExc_ImportError,
810                      "Non-code object in %.200s", cpathname);
811         Py_DECREF(co);
812         return NULL;
813     }
814     return (PyCodeObject *)co;
815 }
816 
817 
818 /* Load a module from a compiled file, execute it, and return its
819    module object WITH INCREMENTED REFERENCE COUNT */
820 
821 static PyObject *
load_compiled_module(char * name,char * cpathname,FILE * fp)822 load_compiled_module(char *name, char *cpathname, FILE *fp)
823 {
824     long magic;
825     PyCodeObject *co;
826     PyObject *m;
827 
828     magic = PyMarshal_ReadLongFromFile(fp);
829     if (magic != pyc_magic) {
830         PyErr_Format(PyExc_ImportError,
831                      "Bad magic number in %.200s", cpathname);
832         return NULL;
833     }
834     (void) PyMarshal_ReadLongFromFile(fp);
835     co = read_compiled_module(cpathname, fp);
836     if (co == NULL)
837         return NULL;
838     if (Py_VerboseFlag)
839         PySys_WriteStderr("import %s # precompiled from %s\n",
840             name, cpathname);
841     m = PyImport_ExecCodeModuleEx(name, (PyObject *)co, cpathname);
842     Py_DECREF(co);
843 
844     return m;
845 }
846 
847 /* Parse a source file and return the corresponding code object */
848 
849 static PyCodeObject *
parse_source_module(const char * pathname,FILE * fp)850 parse_source_module(const char *pathname, FILE *fp)
851 {
852     PyCodeObject *co = NULL;
853     mod_ty mod;
854     PyCompilerFlags flags;
855     PyArena *arena = PyArena_New();
856     if (arena == NULL)
857         return NULL;
858 
859     flags.cf_flags = 0;
860 
861     mod = PyParser_ASTFromFile(fp, pathname, Py_file_input, 0, 0, &flags,
862                                NULL, arena);
863     if (mod) {
864         co = PyAST_Compile(mod, pathname, NULL, arena);
865     }
866     PyArena_Free(arena);
867     return co;
868 }
869 
870 
871 /* Helper to open a bytecode file for writing in exclusive mode */
872 
873 static FILE *
open_exclusive(char * filename,mode_t mode)874 open_exclusive(char *filename, mode_t mode)
875 {
876 #if defined(O_EXCL)&&defined(O_CREAT)&&defined(O_WRONLY)&&defined(O_TRUNC)
877     /* Use O_EXCL to avoid a race condition when another process tries to
878        write the same file.  When that happens, our open() call fails,
879        which is just fine (since it's only a cache).
880        XXX If the file exists and is writable but the directory is not
881        writable, the file will never be written.  Oh well.
882     */
883     int fd;
884     (void) unlink(filename);
885     fd = open(filename, O_EXCL|O_CREAT|O_WRONLY|O_TRUNC
886 #ifdef O_BINARY
887                             |O_BINARY   /* necessary for Windows */
888 #endif
889 #ifdef __VMS
890             , mode, "ctxt=bin", "shr=nil"
891 #else
892             , mode
893 #endif
894           );
895     if (fd < 0)
896         return NULL;
897     return fdopen(fd, "wb");
898 #else
899     /* Best we can do -- on Windows this can't happen anyway */
900     return fopen(filename, "wb");
901 #endif
902 }
903 
904 
905 /* Write a compiled module to a file, placing the time of last
906    modification of its source into the header.
907    Errors are ignored, if a write error occurs an attempt is made to
908    remove the file. */
909 
910 static void
write_compiled_module(PyCodeObject * co,char * cpathname,struct stat * srcstat,time_t mtime)911 write_compiled_module(PyCodeObject *co, char *cpathname, struct stat *srcstat, time_t mtime)
912 {
913     FILE *fp;
914 #ifdef MS_WINDOWS   /* since Windows uses different permissions  */
915     mode_t mode = srcstat->st_mode & ~S_IEXEC;
916     /* Issue #6074: We ensure user write access, so we can delete it later
917      * when the source file changes. (On POSIX, this only requires write
918      * access to the directory, on Windows, we need write access to the file
919      * as well)
920      */
921     mode |= _S_IWRITE;
922 #else
923     mode_t mode = srcstat->st_mode & ~S_IXUSR & ~S_IXGRP & ~S_IXOTH;
924 #endif
925 
926     fp = open_exclusive(cpathname, mode);
927     if (fp == NULL) {
928         if (Py_VerboseFlag)
929             PySys_WriteStderr(
930                 "# can't create %s\n", cpathname);
931         return;
932     }
933     PyMarshal_WriteLongToFile(pyc_magic, fp, Py_MARSHAL_VERSION);
934     /* First write a 0 for mtime */
935     PyMarshal_WriteLongToFile(0L, fp, Py_MARSHAL_VERSION);
936     PyMarshal_WriteObjectToFile((PyObject *)co, fp, Py_MARSHAL_VERSION);
937     if (fflush(fp) != 0 || ferror(fp)) {
938         if (Py_VerboseFlag)
939             PySys_WriteStderr("# can't write %s\n", cpathname);
940         /* Don't keep partial file */
941         fclose(fp);
942         (void) unlink(cpathname);
943         return;
944     }
945     /* Now write the true mtime (as a 32-bit field) */
946     fseek(fp, 4L, 0);
947     assert(mtime <= 0xFFFFFFFF);
948     PyMarshal_WriteLongToFile((long)mtime, fp, Py_MARSHAL_VERSION);
949     fflush(fp);
950     fclose(fp);
951     if (Py_VerboseFlag)
952         PySys_WriteStderr("# wrote %s\n", cpathname);
953 }
954 
955 static void
update_code_filenames(PyCodeObject * co,PyObject * oldname,PyObject * newname)956 update_code_filenames(PyCodeObject *co, PyObject *oldname, PyObject *newname)
957 {
958     PyObject *constants, *tmp;
959     Py_ssize_t i, n;
960 
961     if (!_PyString_Eq(co->co_filename, oldname))
962         return;
963 
964     tmp = co->co_filename;
965     co->co_filename = newname;
966     Py_INCREF(co->co_filename);
967     Py_DECREF(tmp);
968 
969     constants = co->co_consts;
970     n = PyTuple_GET_SIZE(constants);
971     for (i = 0; i < n; i++) {
972         tmp = PyTuple_GET_ITEM(constants, i);
973         if (PyCode_Check(tmp))
974             update_code_filenames((PyCodeObject *)tmp,
975                                   oldname, newname);
976     }
977 }
978 
979 static int
update_compiled_module(PyCodeObject * co,char * pathname)980 update_compiled_module(PyCodeObject *co, char *pathname)
981 {
982     PyObject *oldname, *newname;
983 
984     if (strcmp(PyString_AsString(co->co_filename), pathname) == 0)
985         return 0;
986 
987     newname = PyString_FromString(pathname);
988     if (newname == NULL)
989         return -1;
990 
991     oldname = co->co_filename;
992     Py_INCREF(oldname);
993     update_code_filenames(co, oldname, newname);
994     Py_DECREF(oldname);
995     Py_DECREF(newname);
996     return 1;
997 }
998 
999 #ifdef MS_WINDOWS
1000 
1001 /* Seconds between 1.1.1601 and 1.1.1970 */
1002 static __int64 secs_between_epochs = 11644473600;
1003 
1004 /* Get mtime from file pointer. */
1005 
1006 static time_t
win32_mtime(FILE * fp,char * pathname)1007 win32_mtime(FILE *fp, char *pathname)
1008 {
1009     __int64 filetime;
1010     HANDLE fh;
1011     BY_HANDLE_FILE_INFORMATION file_information;
1012 
1013     fh = (HANDLE)_get_osfhandle(fileno(fp));
1014     if (fh == INVALID_HANDLE_VALUE ||
1015         !GetFileInformationByHandle(fh, &file_information)) {
1016         PyErr_Format(PyExc_RuntimeError,
1017                      "unable to get file status from '%s'",
1018                      pathname);
1019         return -1;
1020     }
1021     /* filetime represents the number of 100ns intervals since
1022        1.1.1601 (UTC).  Convert to seconds since 1.1.1970 (UTC). */
1023     filetime = (__int64)file_information.ftLastWriteTime.dwHighDateTime << 32 |
1024                file_information.ftLastWriteTime.dwLowDateTime;
1025     return filetime / 10000000 - secs_between_epochs;
1026 }
1027 
1028 #endif  /* #ifdef MS_WINDOWS */
1029 
1030 
1031 /* Load a source module from a given file and return its module
1032    object WITH INCREMENTED REFERENCE COUNT.  If there's a matching
1033    byte-compiled file, use that instead. */
1034 
1035 static PyObject *
load_source_module(char * name,char * pathname,FILE * fp)1036 load_source_module(char *name, char *pathname, FILE *fp)
1037 {
1038     struct stat st;
1039     FILE *fpc;
1040     char *buf;
1041     char *cpathname;
1042     PyCodeObject *co = NULL;
1043     PyObject *m;
1044     time_t mtime;
1045 
1046     if (fstat(fileno(fp), &st) != 0) {
1047         PyErr_Format(PyExc_RuntimeError,
1048                      "unable to get file status from '%s'",
1049                      pathname);
1050         return NULL;
1051     }
1052 
1053 #ifdef MS_WINDOWS
1054     mtime = win32_mtime(fp, pathname);
1055     if (mtime == (time_t)-1 && PyErr_Occurred())
1056         return NULL;
1057 #else
1058     mtime = st.st_mtime;
1059 #endif
1060     if (sizeof mtime > 4) {
1061         /* Python's .pyc timestamp handling presumes that the timestamp fits
1062            in 4 bytes. Since the code only does an equality comparison,
1063            ordering is not important and we can safely ignore the higher bits
1064            (collisions are extremely unlikely).
1065          */
1066         mtime &= 0xFFFFFFFF;
1067     }
1068     buf = PyMem_MALLOC(MAXPATHLEN+1);
1069     if (buf == NULL) {
1070         return PyErr_NoMemory();
1071     }
1072     cpathname = make_compiled_pathname(pathname, buf,
1073                                        (size_t)MAXPATHLEN + 1);
1074     if (cpathname != NULL &&
1075         (fpc = check_compiled_module(pathname, mtime, cpathname))) {
1076         co = read_compiled_module(cpathname, fpc);
1077         fclose(fpc);
1078         if (co == NULL)
1079             goto error_exit;
1080         if (update_compiled_module(co, pathname) < 0)
1081             goto error_exit;
1082         if (Py_VerboseFlag)
1083             PySys_WriteStderr("import %s # precompiled from %s\n",
1084                 name, cpathname);
1085         pathname = cpathname;
1086     }
1087     else {
1088         co = parse_source_module(pathname, fp);
1089         if (co == NULL)
1090             goto error_exit;
1091         if (Py_VerboseFlag)
1092             PySys_WriteStderr("import %s # from %s\n",
1093                 name, pathname);
1094         if (cpathname) {
1095             PyObject *ro = PySys_GetObject("dont_write_bytecode");
1096             int b = (ro == NULL) ? 0 : PyObject_IsTrue(ro);
1097             if (b < 0)
1098                 goto error_exit;
1099             if (!b)
1100                 write_compiled_module(co, cpathname, &st, mtime);
1101         }
1102     }
1103     m = PyImport_ExecCodeModuleEx(name, (PyObject *)co, pathname);
1104     Py_DECREF(co);
1105 
1106     PyMem_FREE(buf);
1107     return m;
1108 
1109 error_exit:
1110     Py_XDECREF(co);
1111     PyMem_FREE(buf);
1112     return NULL;
1113 }
1114 
1115 
1116 /* Forward */
1117 static PyObject *load_module(char *, FILE *, char *, int, PyObject *);
1118 static struct filedescr *find_module(char *, char *, PyObject *,
1119                                      char *, size_t, FILE **, PyObject **);
1120 static struct _frozen *find_frozen(char *name);
1121 
1122 /* Load a package and return its module object WITH INCREMENTED
1123    REFERENCE COUNT */
1124 
1125 static PyObject *
load_package(char * name,char * pathname)1126 load_package(char *name, char *pathname)
1127 {
1128     PyObject *m, *d;
1129     PyObject *file = NULL;
1130     PyObject *path = NULL;
1131     int err;
1132     char *buf = NULL;
1133     FILE *fp = NULL;
1134     struct filedescr *fdp;
1135 
1136     m = PyImport_AddModule(name);
1137     if (m == NULL)
1138         return NULL;
1139     if (Py_VerboseFlag)
1140         PySys_WriteStderr("import %s # directory %s\n",
1141             name, pathname);
1142     d = PyModule_GetDict(m);
1143     file = PyString_FromString(pathname);
1144     if (file == NULL)
1145         goto error;
1146     path = Py_BuildValue("[O]", file);
1147     if (path == NULL)
1148         goto error;
1149     err = PyDict_SetItemString(d, "__file__", file);
1150     if (err == 0)
1151         err = PyDict_SetItemString(d, "__path__", path);
1152     if (err != 0)
1153         goto error;
1154     buf = PyMem_MALLOC(MAXPATHLEN+1);
1155     if (buf == NULL) {
1156         PyErr_NoMemory();
1157         goto error;
1158     }
1159     buf[0] = '\0';
1160     fdp = find_module(name, "__init__", path, buf, MAXPATHLEN+1, &fp, NULL);
1161     if (fdp == NULL) {
1162         if (PyErr_ExceptionMatches(PyExc_ImportError)) {
1163             PyErr_Clear();
1164             Py_INCREF(m);
1165         }
1166         else
1167             m = NULL;
1168         goto cleanup;
1169     }
1170     m = load_module(name, fp, buf, fdp->type, NULL);
1171     if (fp != NULL)
1172         fclose(fp);
1173     goto cleanup;
1174 
1175   error:
1176     m = NULL;
1177   cleanup:
1178     if (buf)
1179         PyMem_FREE(buf);
1180     Py_XDECREF(path);
1181     Py_XDECREF(file);
1182     return m;
1183 }
1184 
1185 
1186 /* Helper to test for built-in module */
1187 
1188 static int
is_builtin(char * name)1189 is_builtin(char *name)
1190 {
1191     int i;
1192     for (i = 0; PyImport_Inittab[i].name != NULL; i++) {
1193         if (strcmp(name, PyImport_Inittab[i].name) == 0) {
1194             if (PyImport_Inittab[i].initfunc == NULL)
1195                 return -1;
1196             else
1197                 return 1;
1198         }
1199     }
1200     return 0;
1201 }
1202 
1203 
1204 /* Return an importer object for a sys.path/pkg.__path__ item 'p',
1205    possibly by fetching it from the path_importer_cache dict. If it
1206    wasn't yet cached, traverse path_hooks until a hook is found
1207    that can handle the path item. Return None if no hook could;
1208    this tells our caller it should fall back to the builtin
1209    import mechanism. Cache the result in path_importer_cache.
1210    Returns a borrowed reference. */
1211 
1212 static PyObject *
get_path_importer(PyObject * path_importer_cache,PyObject * path_hooks,PyObject * p)1213 get_path_importer(PyObject *path_importer_cache, PyObject *path_hooks,
1214                   PyObject *p)
1215 {
1216     PyObject *importer;
1217     Py_ssize_t j, nhooks;
1218 
1219     /* These conditions are the caller's responsibility: */
1220     assert(PyList_Check(path_hooks));
1221     assert(PyDict_Check(path_importer_cache));
1222 
1223     nhooks = PyList_Size(path_hooks);
1224     if (nhooks < 0)
1225         return NULL; /* Shouldn't happen */
1226 
1227     importer = PyDict_GetItem(path_importer_cache, p);
1228     if (importer != NULL)
1229         return importer;
1230 
1231     /* set path_importer_cache[p] to None to avoid recursion */
1232     if (PyDict_SetItem(path_importer_cache, p, Py_None) != 0)
1233         return NULL;
1234 
1235     for (j = 0; j < nhooks; j++) {
1236         PyObject *hook = PyList_GetItem(path_hooks, j);
1237         if (hook == NULL)
1238             return NULL;
1239         importer = PyObject_CallFunctionObjArgs(hook, p, NULL);
1240         if (importer != NULL)
1241             break;
1242 
1243         if (!PyErr_ExceptionMatches(PyExc_ImportError)) {
1244             return NULL;
1245         }
1246         PyErr_Clear();
1247     }
1248     if (importer == NULL) {
1249         importer = PyObject_CallFunctionObjArgs(
1250             (PyObject *)&PyNullImporter_Type, p, NULL
1251         );
1252         if (importer == NULL) {
1253             if (PyErr_ExceptionMatches(PyExc_ImportError)) {
1254                 PyErr_Clear();
1255                 return Py_None;
1256             }
1257         }
1258     }
1259     if (importer != NULL) {
1260         int err = PyDict_SetItem(path_importer_cache, p, importer);
1261         Py_DECREF(importer);
1262         if (err != 0)
1263             return NULL;
1264     }
1265     return importer;
1266 }
1267 
1268 PyAPI_FUNC(PyObject *)
PyImport_GetImporter(PyObject * path)1269 PyImport_GetImporter(PyObject *path) {
1270     PyObject *importer=NULL, *path_importer_cache=NULL, *path_hooks=NULL;
1271 
1272     if ((path_importer_cache = PySys_GetObject("path_importer_cache"))) {
1273         if ((path_hooks = PySys_GetObject("path_hooks"))) {
1274             importer = get_path_importer(path_importer_cache,
1275                                          path_hooks, path);
1276         }
1277     }
1278     Py_XINCREF(importer); /* get_path_importer returns a borrowed reference */
1279     return importer;
1280 }
1281 
1282 /* Search the path (default sys.path) for a module.  Return the
1283    corresponding filedescr struct, and (via return arguments) the
1284    pathname and an open file.  Return NULL if the module is not found. */
1285 
1286 #ifdef MS_COREDLL
1287 extern FILE *PyWin_FindRegisteredModule(const char *, struct filedescr **,
1288                                         char *, Py_ssize_t);
1289 #endif
1290 
1291 static int case_ok(char *, Py_ssize_t, Py_ssize_t, char *);
1292 static int find_init_module(char *); /* Forward */
1293 static struct filedescr importhookdescr = {"", "", IMP_HOOK};
1294 
1295 static struct filedescr *
find_module(char * fullname,char * subname,PyObject * path,char * buf,size_t buflen,FILE ** p_fp,PyObject ** p_loader)1296 find_module(char *fullname, char *subname, PyObject *path, char *buf,
1297             size_t buflen, FILE **p_fp, PyObject **p_loader)
1298 {
1299     Py_ssize_t i, npath;
1300     size_t len, namelen;
1301     struct filedescr *fdp = NULL;
1302     char *filemode;
1303     FILE *fp = NULL;
1304     PyObject *path_hooks, *path_importer_cache;
1305     static struct filedescr fd_frozen = {"", "", PY_FROZEN};
1306     static struct filedescr fd_builtin = {"", "", C_BUILTIN};
1307     static struct filedescr fd_package = {"", "", PKG_DIRECTORY};
1308     char *name;
1309 #if defined(PYOS_OS2)
1310     size_t saved_len;
1311     size_t saved_namelen;
1312     char *saved_buf = NULL;
1313 #endif
1314     if (p_loader != NULL)
1315         *p_loader = NULL;
1316 
1317     if (strlen(subname) > MAXPATHLEN) {
1318         PyErr_SetString(PyExc_OverflowError,
1319                         "module name is too long");
1320         return NULL;
1321     }
1322     name = PyMem_MALLOC(MAXPATHLEN+1);
1323     if (name == NULL) {
1324         PyErr_NoMemory();
1325         return NULL;
1326     }
1327     strcpy(name, subname);
1328 
1329     /* sys.meta_path import hook */
1330     if (p_loader != NULL) {
1331         PyObject *meta_path;
1332 
1333         meta_path = PySys_GetObject("meta_path");
1334         if (meta_path == NULL || !PyList_Check(meta_path)) {
1335             PyErr_SetString(PyExc_RuntimeError,
1336                             "sys.meta_path must be a list of "
1337                             "import hooks");
1338             goto error_exit;
1339         }
1340         Py_INCREF(meta_path);  /* zap guard */
1341         npath = PyList_Size(meta_path);
1342         for (i = 0; i < npath; i++) {
1343             PyObject *loader;
1344             PyObject *hook = PyList_GetItem(meta_path, i);
1345             loader = PyObject_CallMethod(hook, "find_module",
1346                                          "sO", fullname,
1347                                          path != NULL ?
1348                                          path : Py_None);
1349             if (loader == NULL) {
1350                 Py_DECREF(meta_path);
1351                 goto error_exit;  /* true error */
1352             }
1353             if (loader != Py_None) {
1354                 /* a loader was found */
1355                 *p_loader = loader;
1356                 Py_DECREF(meta_path);
1357                 PyMem_FREE(name);
1358                 return &importhookdescr;
1359             }
1360             Py_DECREF(loader);
1361         }
1362         Py_DECREF(meta_path);
1363     }
1364 
1365     if (path != NULL && PyString_Check(path)) {
1366         /* The only type of submodule allowed inside a "frozen"
1367            package are other frozen modules or packages. */
1368         if (PyString_Size(path) + 1 + strlen(name) >= (size_t)buflen) {
1369             PyErr_SetString(PyExc_ImportError,
1370                             "full frozen module name too long");
1371             goto error_exit;
1372         }
1373         strcpy(buf, PyString_AsString(path));
1374         strcat(buf, ".");
1375         strcat(buf, name);
1376         strcpy(name, buf);
1377         if (find_frozen(name) != NULL) {
1378             strcpy(buf, name);
1379             PyMem_FREE(name);
1380             return &fd_frozen;
1381         }
1382         PyErr_Format(PyExc_ImportError,
1383                      "No frozen submodule named %.200s", name);
1384         goto error_exit;
1385     }
1386     if (path == NULL) {
1387         if (is_builtin(name)) {
1388             strcpy(buf, name);
1389             PyMem_FREE(name);
1390             return &fd_builtin;
1391         }
1392         if ((find_frozen(name)) != NULL) {
1393             strcpy(buf, name);
1394             PyMem_FREE(name);
1395             return &fd_frozen;
1396         }
1397 
1398 #ifdef MS_COREDLL
1399         fp = PyWin_FindRegisteredModule(name, &fdp, buf, buflen);
1400         if (fp != NULL) {
1401             *p_fp = fp;
1402             PyMem_FREE(name);
1403             return fdp;
1404         }
1405 #endif
1406         path = PySys_GetObject("path");
1407     }
1408     if (path == NULL || !PyList_Check(path)) {
1409         PyErr_SetString(PyExc_RuntimeError,
1410                         "sys.path must be a list of directory names");
1411         goto error_exit;
1412     }
1413 
1414     path_hooks = PySys_GetObject("path_hooks");
1415     if (path_hooks == NULL || !PyList_Check(path_hooks)) {
1416         PyErr_SetString(PyExc_RuntimeError,
1417                         "sys.path_hooks must be a list of "
1418                         "import hooks");
1419         goto error_exit;
1420     }
1421     path_importer_cache = PySys_GetObject("path_importer_cache");
1422     if (path_importer_cache == NULL ||
1423         !PyDict_Check(path_importer_cache)) {
1424         PyErr_SetString(PyExc_RuntimeError,
1425                         "sys.path_importer_cache must be a dict");
1426         goto error_exit;
1427     }
1428 
1429     npath = PyList_Size(path);
1430     namelen = strlen(name);
1431     for (i = 0; i < npath; i++) {
1432         PyObject *copy = NULL;
1433         PyObject *v = PyList_GetItem(path, i);
1434         if (!v)
1435             goto error_exit;
1436 #ifdef Py_USING_UNICODE
1437         if (PyUnicode_Check(v)) {
1438             copy = PyUnicode_Encode(PyUnicode_AS_UNICODE(v),
1439                 PyUnicode_GET_SIZE(v), Py_FileSystemDefaultEncoding, NULL);
1440             if (copy == NULL)
1441                 goto error_exit;
1442             v = copy;
1443         }
1444         else
1445 #endif
1446         if (!PyString_Check(v))
1447             continue;
1448         len = PyString_GET_SIZE(v);
1449         if (len + 2 + namelen + MAXSUFFIXSIZE >= buflen) {
1450             Py_XDECREF(copy);
1451             continue; /* Too long */
1452         }
1453         strcpy(buf, PyString_AS_STRING(v));
1454         if (strlen(buf) != len) {
1455             Py_XDECREF(copy);
1456             continue; /* v contains '\0' */
1457         }
1458 
1459         /* sys.path_hooks import hook */
1460         if (p_loader != NULL) {
1461             PyObject *importer;
1462 
1463             importer = get_path_importer(path_importer_cache,
1464                                          path_hooks, v);
1465             if (importer == NULL) {
1466                 Py_XDECREF(copy);
1467                 goto error_exit;
1468             }
1469             /* Note: importer is a borrowed reference */
1470             if (importer != Py_None) {
1471                 PyObject *loader;
1472                 loader = PyObject_CallMethod(importer,
1473                                              "find_module",
1474                                              "s", fullname);
1475                 Py_XDECREF(copy);
1476                 if (loader == NULL)
1477                     goto error_exit;  /* error */
1478                 if (loader != Py_None) {
1479                     /* a loader was found */
1480                     *p_loader = loader;
1481                     PyMem_FREE(name);
1482                     return &importhookdescr;
1483                 }
1484                 Py_DECREF(loader);
1485                 continue;
1486             }
1487         }
1488         /* no hook was found, use builtin import */
1489 
1490         if (len > 0 && buf[len-1] != SEP
1491 #ifdef ALTSEP
1492             && buf[len-1] != ALTSEP
1493 #endif
1494             )
1495             buf[len++] = SEP;
1496         strcpy(buf+len, name);
1497         len += namelen;
1498 
1499         /* Check for package import (buf holds a directory name,
1500            and there's an __init__ module in that directory */
1501         if (isdir(buf) &&         /* it's an existing directory */
1502             case_ok(buf, len, namelen, name)) { /* case matches */
1503             if (find_init_module(buf)) { /* and has __init__.py */
1504                 Py_XDECREF(copy);
1505                 PyMem_FREE(name);
1506                 return &fd_package;
1507             }
1508             else {
1509                 char warnstr[MAXPATHLEN+80];
1510                 sprintf(warnstr, "Not importing directory "
1511                     "'%.*s': missing __init__.py",
1512                     MAXPATHLEN, buf);
1513                 if (PyErr_Warn(PyExc_ImportWarning,
1514                                warnstr)) {
1515                     Py_XDECREF(copy);
1516                     goto error_exit;
1517                 }
1518             }
1519         }
1520 #if defined(PYOS_OS2)
1521         /* take a snapshot of the module spec for restoration
1522          * after the 8 character DLL hackery
1523          */
1524         saved_buf = strdup(buf);
1525         saved_len = len;
1526         saved_namelen = namelen;
1527 #endif /* PYOS_OS2 */
1528         for (fdp = _PyImport_Filetab; fdp->suffix != NULL; fdp++) {
1529 #if defined(PYOS_OS2) && defined(HAVE_DYNAMIC_LOADING)
1530             /* OS/2 limits DLLs to 8 character names (w/o
1531                extension)
1532              * so if the name is longer than that and its a
1533              * dynamically loaded module we're going to try,
1534              * truncate the name before trying
1535              */
1536             if (strlen(subname) > 8) {
1537                 /* is this an attempt to load a C extension? */
1538                 const struct filedescr *scan;
1539                 scan = _PyImport_DynLoadFiletab;
1540                 while (scan->suffix != NULL) {
1541                     if (!strcmp(scan->suffix, fdp->suffix))
1542                         break;
1543                     else
1544                         scan++;
1545                 }
1546                 if (scan->suffix != NULL) {
1547                     /* yes, so truncate the name */
1548                     namelen = 8;
1549                     len -= strlen(subname) - namelen;
1550                     buf[len] = '\0';
1551                 }
1552             }
1553 #endif /* PYOS_OS2 */
1554             strcpy(buf+len, fdp->suffix);
1555             if (Py_VerboseFlag > 1)
1556                 PySys_WriteStderr("# trying %s\n", buf);
1557             filemode = fdp->mode;
1558             if (filemode[0] == 'U')
1559                 filemode = "r" PY_STDIOTEXTMODE;
1560             fp = fopen(buf, filemode);
1561             if (fp != NULL) {
1562                 if (case_ok(buf, len, namelen, name))
1563                     break;
1564                 else {                   /* continue search */
1565                     fclose(fp);
1566                     fp = NULL;
1567                 }
1568             }
1569 #if defined(PYOS_OS2)
1570             /* restore the saved snapshot */
1571             strcpy(buf, saved_buf);
1572             len = saved_len;
1573             namelen = saved_namelen;
1574 #endif
1575         }
1576 #if defined(PYOS_OS2)
1577         /* don't need/want the module name snapshot anymore */
1578         if (saved_buf)
1579         {
1580             free(saved_buf);
1581             saved_buf = NULL;
1582         }
1583 #endif
1584         Py_XDECREF(copy);
1585         if (fp != NULL)
1586             break;
1587     }
1588     if (fp == NULL) {
1589         PyErr_Format(PyExc_ImportError,
1590                      "No module named %.200s", name);
1591         goto error_exit;
1592     }
1593     *p_fp = fp;
1594     PyMem_FREE(name);
1595     return fdp;
1596 
1597 error_exit:
1598     PyMem_FREE(name);
1599     return NULL;
1600 }
1601 
1602 /* Helpers for main.c
1603  *  Find the source file corresponding to a named module
1604  */
1605 struct filedescr *
_PyImport_FindModule(const char * name,PyObject * path,char * buf,size_t buflen,FILE ** p_fp,PyObject ** p_loader)1606 _PyImport_FindModule(const char *name, PyObject *path, char *buf,
1607             size_t buflen, FILE **p_fp, PyObject **p_loader)
1608 {
1609     return find_module((char *) name, (char *) name, path,
1610                        buf, buflen, p_fp, p_loader);
1611 }
1612 
_PyImport_IsScript(struct filedescr * fd)1613 PyAPI_FUNC(int) _PyImport_IsScript(struct filedescr * fd)
1614 {
1615     return fd->type == PY_SOURCE || fd->type == PY_COMPILED;
1616 }
1617 
1618 /* case_ok(char* buf, Py_ssize_t len, Py_ssize_t namelen, char* name)
1619  * The arguments here are tricky, best shown by example:
1620  *    /a/b/c/d/e/f/g/h/i/j/k/some_long_module_name.py\0
1621  *    ^                      ^                   ^    ^
1622  *    |--------------------- buf ---------------------|
1623  *    |------------------- len ------------------|
1624  *                           |------ name -------|
1625  *                           |----- namelen -----|
1626  * buf is the full path, but len only counts up to (& exclusive of) the
1627  * extension.  name is the module name, also exclusive of extension.
1628  *
1629  * We've already done a successful stat() or fopen() on buf, so know that
1630  * there's some match, possibly case-insensitive.
1631  *
1632  * case_ok() is to return 1 if there's a case-sensitive match for
1633  * name, else 0.  case_ok() is also to return 1 if envar PYTHONCASEOK
1634  * exists.
1635  *
1636  * case_ok() is used to implement case-sensitive import semantics even
1637  * on platforms with case-insensitive filesystems.  It's trivial to implement
1638  * for case-sensitive filesystems.  It's pretty much a cross-platform
1639  * nightmare for systems with case-insensitive filesystems.
1640  */
1641 
1642 /* First we may need a pile of platform-specific header files; the sequence
1643  * of #if's here should match the sequence in the body of case_ok().
1644  */
1645 #if defined(MS_WINDOWS)
1646 #include <windows.h>
1647 
1648 #elif defined(DJGPP)
1649 #include <dir.h>
1650 
1651 #elif (defined(__MACH__) && defined(__APPLE__) || defined(__CYGWIN__)) && defined(HAVE_DIRENT_H)
1652 #include <sys/types.h>
1653 #include <dirent.h>
1654 
1655 #elif defined(PYOS_OS2)
1656 #define INCL_DOS
1657 #define INCL_DOSERRORS
1658 #define INCL_NOPMAPI
1659 #include <os2.h>
1660 
1661 #elif defined(RISCOS)
1662 #include "oslib/osfscontrol.h"
1663 #endif
1664 
1665 static int
case_ok(char * buf,Py_ssize_t len,Py_ssize_t namelen,char * name)1666 case_ok(char *buf, Py_ssize_t len, Py_ssize_t namelen, char *name)
1667 {
1668 /* Pick a platform-specific implementation; the sequence of #if's here should
1669  * match the sequence just above.
1670  */
1671 
1672 /* MS_WINDOWS */
1673 #if defined(MS_WINDOWS)
1674     WIN32_FIND_DATA data;
1675     HANDLE h;
1676 
1677     if (Py_GETENV("PYTHONCASEOK") != NULL)
1678         return 1;
1679 
1680     h = FindFirstFile(buf, &data);
1681     if (h == INVALID_HANDLE_VALUE) {
1682         PyErr_Format(PyExc_NameError,
1683           "Can't find file for module %.100s\n(filename %.300s)",
1684           name, buf);
1685         return 0;
1686     }
1687     FindClose(h);
1688     return strncmp(data.cFileName, name, namelen) == 0;
1689 
1690 /* DJGPP */
1691 #elif defined(DJGPP)
1692     struct ffblk ffblk;
1693     int done;
1694 
1695     if (Py_GETENV("PYTHONCASEOK") != NULL)
1696         return 1;
1697 
1698     done = findfirst(buf, &ffblk, FA_ARCH|FA_RDONLY|FA_HIDDEN|FA_DIREC);
1699     if (done) {
1700         PyErr_Format(PyExc_NameError,
1701           "Can't find file for module %.100s\n(filename %.300s)",
1702           name, buf);
1703         return 0;
1704     }
1705     return strncmp(ffblk.ff_name, name, namelen) == 0;
1706 
1707 /* new-fangled macintosh (macosx) or Cygwin */
1708 #elif (defined(__MACH__) && defined(__APPLE__) || defined(__CYGWIN__)) && defined(HAVE_DIRENT_H)
1709     DIR *dirp;
1710     struct dirent *dp;
1711     char dirname[MAXPATHLEN + 1];
1712     const int dirlen = len - namelen - 1; /* don't want trailing SEP */
1713 
1714     if (Py_GETENV("PYTHONCASEOK") != NULL)
1715         return 1;
1716 
1717     /* Copy the dir component into dirname; substitute "." if empty */
1718     if (dirlen <= 0) {
1719         dirname[0] = '.';
1720         dirname[1] = '\0';
1721     }
1722     else {
1723         assert(dirlen <= MAXPATHLEN);
1724         memcpy(dirname, buf, dirlen);
1725         dirname[dirlen] = '\0';
1726     }
1727     /* Open the directory and search the entries for an exact match. */
1728     dirp = opendir(dirname);
1729     if (dirp) {
1730         char *nameWithExt = buf + len - namelen;
1731         while ((dp = readdir(dirp)) != NULL) {
1732             const int thislen =
1733 #ifdef _DIRENT_HAVE_D_NAMELEN
1734                                     dp->d_namlen;
1735 #else
1736                                     strlen(dp->d_name);
1737 #endif
1738             if (thislen >= namelen &&
1739                 strcmp(dp->d_name, nameWithExt) == 0) {
1740                 (void)closedir(dirp);
1741                 return 1; /* Found */
1742             }
1743         }
1744         (void)closedir(dirp);
1745     }
1746     return 0 ; /* Not found */
1747 
1748 /* RISC OS */
1749 #elif defined(RISCOS)
1750     char canon[MAXPATHLEN+1]; /* buffer for the canonical form of the path */
1751     char buf2[MAXPATHLEN+2];
1752     char *nameWithExt = buf+len-namelen;
1753     int canonlen;
1754     os_error *e;
1755 
1756     if (Py_GETENV("PYTHONCASEOK") != NULL)
1757         return 1;
1758 
1759     /* workaround:
1760        append wildcard, otherwise case of filename wouldn't be touched */
1761     strcpy(buf2, buf);
1762     strcat(buf2, "*");
1763 
1764     e = xosfscontrol_canonicalise_path(buf2,canon,0,0,MAXPATHLEN+1,&canonlen);
1765     canonlen = MAXPATHLEN+1-canonlen;
1766     if (e || canonlen<=0 || canonlen>(MAXPATHLEN+1) )
1767         return 0;
1768     if (strcmp(nameWithExt, canon+canonlen-strlen(nameWithExt))==0)
1769         return 1; /* match */
1770 
1771     return 0;
1772 
1773 /* OS/2 */
1774 #elif defined(PYOS_OS2)
1775     HDIR hdir = 1;
1776     ULONG srchcnt = 1;
1777     FILEFINDBUF3 ffbuf;
1778     APIRET rc;
1779 
1780     if (Py_GETENV("PYTHONCASEOK") != NULL)
1781         return 1;
1782 
1783     rc = DosFindFirst(buf,
1784                       &hdir,
1785                       FILE_READONLY | FILE_HIDDEN | FILE_SYSTEM | FILE_DIRECTORY,
1786                       &ffbuf, sizeof(ffbuf),
1787                       &srchcnt,
1788                       FIL_STANDARD);
1789     if (rc != NO_ERROR)
1790         return 0;
1791     return strncmp(ffbuf.achName, name, namelen) == 0;
1792 
1793 /* assuming it's a case-sensitive filesystem, so there's nothing to do! */
1794 #else
1795     return 1;
1796 
1797 #endif
1798 }
1799 
1800 
1801 #ifdef HAVE_STAT
1802 /* Helper to look for __init__.py or __init__.py[co] in potential package */
1803 static int
find_init_module(char * buf)1804 find_init_module(char *buf)
1805 {
1806     const size_t save_len = strlen(buf);
1807     size_t i = save_len;
1808     char *pname;  /* pointer to start of __init__ */
1809     struct stat statbuf;
1810 
1811 /*      For calling case_ok(buf, len, namelen, name):
1812  *      /a/b/c/d/e/f/g/h/i/j/k/some_long_module_name.py\0
1813  *      ^                      ^                   ^    ^
1814  *      |--------------------- buf ---------------------|
1815  *      |------------------- len ------------------|
1816  *                             |------ name -------|
1817  *                             |----- namelen -----|
1818  */
1819     if (save_len + 13 >= MAXPATHLEN)
1820         return 0;
1821     buf[i++] = SEP;
1822     pname = buf + i;
1823     strcpy(pname, "__init__.py");
1824     if (stat(buf, &statbuf) == 0) {
1825         if (case_ok(buf,
1826                     save_len + 9,               /* len("/__init__") */
1827                 8,                              /* len("__init__") */
1828                 pname)) {
1829             buf[save_len] = '\0';
1830             return 1;
1831         }
1832     }
1833     i += strlen(pname);
1834     strcpy(buf+i, Py_OptimizeFlag ? "o" : "c");
1835     if (stat(buf, &statbuf) == 0) {
1836         if (case_ok(buf,
1837                     save_len + 9,               /* len("/__init__") */
1838                 8,                              /* len("__init__") */
1839                 pname)) {
1840             buf[save_len] = '\0';
1841             return 1;
1842         }
1843     }
1844     buf[save_len] = '\0';
1845     return 0;
1846 }
1847 
1848 #else
1849 
1850 #ifdef RISCOS
1851 static int
find_init_module(buf)1852 find_init_module(buf)
1853     char *buf;
1854 {
1855     int save_len = strlen(buf);
1856     int i = save_len;
1857 
1858     if (save_len + 13 >= MAXPATHLEN)
1859         return 0;
1860     buf[i++] = SEP;
1861     strcpy(buf+i, "__init__/py");
1862     if (isfile(buf)) {
1863         buf[save_len] = '\0';
1864         return 1;
1865     }
1866 
1867     if (Py_OptimizeFlag)
1868         strcpy(buf+i, "o");
1869     else
1870         strcpy(buf+i, "c");
1871     if (isfile(buf)) {
1872         buf[save_len] = '\0';
1873         return 1;
1874     }
1875     buf[save_len] = '\0';
1876     return 0;
1877 }
1878 #endif /*RISCOS*/
1879 
1880 #endif /* HAVE_STAT */
1881 
1882 
1883 static int init_builtin(char *); /* Forward */
1884 
1885 /* Load an external module using the default search path and return
1886    its module object WITH INCREMENTED REFERENCE COUNT */
1887 
1888 static PyObject *
load_module(char * name,FILE * fp,char * pathname,int type,PyObject * loader)1889 load_module(char *name, FILE *fp, char *pathname, int type, PyObject *loader)
1890 {
1891     PyObject *modules;
1892     PyObject *m;
1893     int err;
1894 
1895     /* First check that there's an open file (if we need one)  */
1896     switch (type) {
1897     case PY_SOURCE:
1898     case PY_COMPILED:
1899         if (fp == NULL) {
1900             PyErr_Format(PyExc_ValueError,
1901                "file object required for import (type code %d)",
1902                          type);
1903             return NULL;
1904         }
1905     }
1906 
1907     switch (type) {
1908 
1909     case PY_SOURCE:
1910         m = load_source_module(name, pathname, fp);
1911         break;
1912 
1913     case PY_COMPILED:
1914         m = load_compiled_module(name, pathname, fp);
1915         break;
1916 
1917 #ifdef HAVE_DYNAMIC_LOADING
1918     case C_EXTENSION:
1919         m = _PyImport_LoadDynamicModule(name, pathname, fp);
1920         break;
1921 #endif
1922 
1923     case PKG_DIRECTORY:
1924         m = load_package(name, pathname);
1925         break;
1926 
1927     case C_BUILTIN:
1928     case PY_FROZEN:
1929         if (pathname != NULL && pathname[0] != '\0')
1930             name = pathname;
1931         if (type == C_BUILTIN)
1932             err = init_builtin(name);
1933         else
1934             err = PyImport_ImportFrozenModule(name);
1935         if (err < 0)
1936             return NULL;
1937         if (err == 0) {
1938             PyErr_Format(PyExc_ImportError,
1939                          "Purported %s module %.200s not found",
1940                          type == C_BUILTIN ?
1941                                     "builtin" : "frozen",
1942                          name);
1943             return NULL;
1944         }
1945         modules = PyImport_GetModuleDict();
1946         m = PyDict_GetItemString(modules, name);
1947         if (m == NULL) {
1948             PyErr_Format(
1949                 PyExc_ImportError,
1950                 "%s module %.200s not properly initialized",
1951                 type == C_BUILTIN ?
1952                     "builtin" : "frozen",
1953                 name);
1954             return NULL;
1955         }
1956         Py_INCREF(m);
1957         break;
1958 
1959     case IMP_HOOK: {
1960         if (loader == NULL) {
1961             PyErr_SetString(PyExc_ImportError,
1962                             "import hook without loader");
1963             return NULL;
1964         }
1965         m = PyObject_CallMethod(loader, "load_module", "s", name);
1966         break;
1967     }
1968 
1969     default:
1970         PyErr_Format(PyExc_ImportError,
1971                      "Don't know how to import %.200s (type code %d)",
1972                       name, type);
1973         m = NULL;
1974 
1975     }
1976 
1977     return m;
1978 }
1979 
1980 
1981 /* Initialize a built-in module.
1982    Return 1 for success, 0 if the module is not found, and -1 with
1983    an exception set if the initialization failed. */
1984 
1985 static int
init_builtin(char * name)1986 init_builtin(char *name)
1987 {
1988     struct _inittab *p;
1989 
1990     if (_PyImport_FindExtension(name, name) != NULL)
1991         return 1;
1992 
1993     for (p = PyImport_Inittab; p->name != NULL; p++) {
1994         if (strcmp(name, p->name) == 0) {
1995             if (p->initfunc == NULL) {
1996                 PyErr_Format(PyExc_ImportError,
1997                     "Cannot re-init internal module %.200s",
1998                     name);
1999                 return -1;
2000             }
2001             if (Py_VerboseFlag)
2002                 PySys_WriteStderr("import %s # builtin\n", name);
2003             (*p->initfunc)();
2004             if (PyErr_Occurred())
2005                 return -1;
2006             if (_PyImport_FixupExtension(name, name) == NULL)
2007                 return -1;
2008             return 1;
2009         }
2010     }
2011     return 0;
2012 }
2013 
2014 
2015 /* Frozen modules */
2016 
2017 static struct _frozen *
find_frozen(char * name)2018 find_frozen(char *name)
2019 {
2020     struct _frozen *p;
2021 
2022     for (p = PyImport_FrozenModules; ; p++) {
2023         if (p->name == NULL)
2024             return NULL;
2025         if (strcmp(p->name, name) == 0)
2026             break;
2027     }
2028     return p;
2029 }
2030 
2031 static PyObject *
get_frozen_object(char * name)2032 get_frozen_object(char *name)
2033 {
2034     struct _frozen *p = find_frozen(name);
2035     int size;
2036 
2037     if (p == NULL) {
2038         PyErr_Format(PyExc_ImportError,
2039                      "No such frozen object named %.200s",
2040                      name);
2041         return NULL;
2042     }
2043     if (p->code == NULL) {
2044         PyErr_Format(PyExc_ImportError,
2045                      "Excluded frozen object named %.200s",
2046                      name);
2047         return NULL;
2048     }
2049     size = p->size;
2050     if (size < 0)
2051         size = -size;
2052     return PyMarshal_ReadObjectFromString((char *)p->code, size);
2053 }
2054 
2055 /* Initialize a frozen module.
2056    Return 1 for succes, 0 if the module is not found, and -1 with
2057    an exception set if the initialization failed.
2058    This function is also used from frozenmain.c */
2059 
2060 int
PyImport_ImportFrozenModule(char * name)2061 PyImport_ImportFrozenModule(char *name)
2062 {
2063     struct _frozen *p = find_frozen(name);
2064     PyObject *co;
2065     PyObject *m;
2066     int ispackage;
2067     int size;
2068 
2069     if (p == NULL)
2070         return 0;
2071     if (p->code == NULL) {
2072         PyErr_Format(PyExc_ImportError,
2073                      "Excluded frozen object named %.200s",
2074                      name);
2075         return -1;
2076     }
2077     size = p->size;
2078     ispackage = (size < 0);
2079     if (ispackage)
2080         size = -size;
2081     if (Py_VerboseFlag)
2082         PySys_WriteStderr("import %s # frozen%s\n",
2083             name, ispackage ? " package" : "");
2084     co = PyMarshal_ReadObjectFromString((char *)p->code, size);
2085     if (co == NULL)
2086         return -1;
2087     if (!PyCode_Check(co)) {
2088         PyErr_Format(PyExc_TypeError,
2089                      "frozen object %.200s is not a code object",
2090                      name);
2091         goto err_return;
2092     }
2093     if (ispackage) {
2094         /* Set __path__ to the package name */
2095         PyObject *d, *s;
2096         int err;
2097         m = PyImport_AddModule(name);
2098         if (m == NULL)
2099             goto err_return;
2100         d = PyModule_GetDict(m);
2101         s = PyString_InternFromString(name);
2102         if (s == NULL)
2103             goto err_return;
2104         err = PyDict_SetItemString(d, "__path__", s);
2105         Py_DECREF(s);
2106         if (err != 0)
2107             goto err_return;
2108     }
2109     m = PyImport_ExecCodeModuleEx(name, co, "<frozen>");
2110     if (m == NULL)
2111         goto err_return;
2112     Py_DECREF(co);
2113     Py_DECREF(m);
2114     return 1;
2115 err_return:
2116     Py_DECREF(co);
2117     return -1;
2118 }
2119 
2120 
2121 /* Import a module, either built-in, frozen, or external, and return
2122    its module object WITH INCREMENTED REFERENCE COUNT */
2123 
2124 PyObject *
PyImport_ImportModule(const char * name)2125 PyImport_ImportModule(const char *name)
2126 {
2127     PyObject *pname;
2128     PyObject *result;
2129 
2130     pname = PyString_FromString(name);
2131     if (pname == NULL)
2132         return NULL;
2133     result = PyImport_Import(pname);
2134     Py_DECREF(pname);
2135     return result;
2136 }
2137 
2138 /* Import a module without blocking
2139  *
2140  * At first it tries to fetch the module from sys.modules. If the module was
2141  * never loaded before it loads it with PyImport_ImportModule() unless another
2142  * thread holds the import lock. In the latter case the function raises an
2143  * ImportError instead of blocking.
2144  *
2145  * Returns the module object with incremented ref count.
2146  */
2147 PyObject *
PyImport_ImportModuleNoBlock(const char * name)2148 PyImport_ImportModuleNoBlock(const char *name)
2149 {
2150     PyObject *result;
2151     PyObject *modules;
2152 #ifdef WITH_THREAD
2153     long me;
2154 #endif
2155 
2156     /* Try to get the module from sys.modules[name] */
2157     modules = PyImport_GetModuleDict();
2158     if (modules == NULL)
2159         return NULL;
2160 
2161     result = PyDict_GetItemString(modules, name);
2162     if (result != NULL) {
2163         Py_INCREF(result);
2164         return result;
2165     }
2166     else {
2167         PyErr_Clear();
2168     }
2169 #ifdef WITH_THREAD
2170     /* check the import lock
2171      * me might be -1 but I ignore the error here, the lock function
2172      * takes care of the problem */
2173     me = PyThread_get_thread_ident();
2174     if (import_lock_thread == -1 || import_lock_thread == me) {
2175         /* no thread or me is holding the lock */
2176         return PyImport_ImportModule(name);
2177     }
2178     else {
2179         PyErr_Format(PyExc_ImportError,
2180                      "Failed to import %.200s because the import lock"
2181                      "is held by another thread.",
2182                      name);
2183         return NULL;
2184     }
2185 #else
2186     return PyImport_ImportModule(name);
2187 #endif
2188 }
2189 
2190 /* Forward declarations for helper routines */
2191 static PyObject *get_parent(PyObject *globals, char *buf,
2192                             Py_ssize_t *p_buflen, int level);
2193 static PyObject *load_next(PyObject *mod, PyObject *altmod,
2194                            char **p_name, char *buf, Py_ssize_t *p_buflen);
2195 static int mark_miss(char *name);
2196 static int ensure_fromlist(PyObject *mod, PyObject *fromlist,
2197                            char *buf, Py_ssize_t buflen, int recursive);
2198 static PyObject * import_submodule(PyObject *mod, char *name, char *fullname);
2199 
2200 /* The Magnum Opus of dotted-name import :-) */
2201 
2202 static PyObject *
import_module_level(char * name,PyObject * globals,PyObject * locals,PyObject * fromlist,int level)2203 import_module_level(char *name, PyObject *globals, PyObject *locals,
2204                     PyObject *fromlist, int level)
2205 {
2206     char *buf;
2207     Py_ssize_t buflen = 0;
2208     PyObject *parent, *head, *next, *tail;
2209 
2210     if (strchr(name, '/') != NULL
2211 #ifdef MS_WINDOWS
2212         || strchr(name, '\\') != NULL
2213 #endif
2214         ) {
2215         PyErr_SetString(PyExc_ImportError,
2216                         "Import by filename is not supported.");
2217         return NULL;
2218     }
2219 
2220     buf = PyMem_MALLOC(MAXPATHLEN+1);
2221     if (buf == NULL) {
2222         return PyErr_NoMemory();
2223     }
2224     parent = get_parent(globals, buf, &buflen, level);
2225     if (parent == NULL)
2226         goto error_exit;
2227 
2228     head = load_next(parent, level < 0 ? Py_None : parent, &name, buf,
2229                         &buflen);
2230     if (head == NULL)
2231         goto error_exit;
2232 
2233     tail = head;
2234     Py_INCREF(tail);
2235     while (name) {
2236         next = load_next(tail, tail, &name, buf, &buflen);
2237         Py_DECREF(tail);
2238         if (next == NULL) {
2239             Py_DECREF(head);
2240             goto error_exit;
2241         }
2242         tail = next;
2243     }
2244     if (tail == Py_None) {
2245         /* If tail is Py_None, both get_parent and load_next found
2246            an empty module name: someone called __import__("") or
2247            doctored faulty bytecode */
2248         Py_DECREF(tail);
2249         Py_DECREF(head);
2250         PyErr_SetString(PyExc_ValueError,
2251                         "Empty module name");
2252         goto error_exit;
2253     }
2254 
2255     if (fromlist != NULL) {
2256         int b = (fromlist == Py_None) ? 0 : PyObject_IsTrue(fromlist);
2257         if (b < 0) {
2258             Py_DECREF(tail);
2259             Py_DECREF(head);
2260             goto error_exit;
2261         }
2262         if (!b)
2263             fromlist = NULL;
2264     }
2265 
2266     if (fromlist == NULL) {
2267         Py_DECREF(tail);
2268         PyMem_FREE(buf);
2269         return head;
2270     }
2271 
2272     Py_DECREF(head);
2273     if (!ensure_fromlist(tail, fromlist, buf, buflen, 0)) {
2274         Py_DECREF(tail);
2275         goto error_exit;
2276     }
2277 
2278     PyMem_FREE(buf);
2279     return tail;
2280 
2281 error_exit:
2282     PyMem_FREE(buf);
2283     return NULL;
2284 }
2285 
2286 PyObject *
PyImport_ImportModuleLevel(char * name,PyObject * globals,PyObject * locals,PyObject * fromlist,int level)2287 PyImport_ImportModuleLevel(char *name, PyObject *globals, PyObject *locals,
2288                          PyObject *fromlist, int level)
2289 {
2290     PyObject *result;
2291     _PyImport_AcquireLock();
2292     result = import_module_level(name, globals, locals, fromlist, level);
2293     if (_PyImport_ReleaseLock() < 0) {
2294         Py_XDECREF(result);
2295         PyErr_SetString(PyExc_RuntimeError,
2296                         "not holding the import lock");
2297         return NULL;
2298     }
2299     return result;
2300 }
2301 
2302 /* Return the package that an import is being performed in.  If globals comes
2303    from the module foo.bar.bat (not itself a package), this returns the
2304    sys.modules entry for foo.bar.  If globals is from a package's __init__.py,
2305    the package's entry in sys.modules is returned, as a borrowed reference.
2306 
2307    The *name* of the returned package is returned in buf, with the length of
2308    the name in *p_buflen.
2309 
2310    If globals doesn't come from a package or a module in a package, or a
2311    corresponding entry is not found in sys.modules, Py_None is returned.
2312 */
2313 static PyObject *
get_parent(PyObject * globals,char * buf,Py_ssize_t * p_buflen,int level)2314 get_parent(PyObject *globals, char *buf, Py_ssize_t *p_buflen, int level)
2315 {
2316     static PyObject *namestr = NULL;
2317     static PyObject *pathstr = NULL;
2318     static PyObject *pkgstr = NULL;
2319     PyObject *pkgname, *modname, *modpath, *modules, *parent;
2320     int orig_level = level;
2321 
2322     if (globals == NULL || !PyDict_Check(globals) || !level)
2323         return Py_None;
2324 
2325     if (namestr == NULL) {
2326         namestr = PyString_InternFromString("__name__");
2327         if (namestr == NULL)
2328             return NULL;
2329     }
2330     if (pathstr == NULL) {
2331         pathstr = PyString_InternFromString("__path__");
2332         if (pathstr == NULL)
2333             return NULL;
2334     }
2335     if (pkgstr == NULL) {
2336         pkgstr = PyString_InternFromString("__package__");
2337         if (pkgstr == NULL)
2338             return NULL;
2339     }
2340 
2341     *buf = '\0';
2342     *p_buflen = 0;
2343     pkgname = PyDict_GetItem(globals, pkgstr);
2344 
2345     if ((pkgname != NULL) && (pkgname != Py_None)) {
2346         /* __package__ is set, so use it */
2347         Py_ssize_t len;
2348         if (!PyString_Check(pkgname)) {
2349             PyErr_SetString(PyExc_ValueError,
2350                             "__package__ set to non-string");
2351             return NULL;
2352         }
2353         len = PyString_GET_SIZE(pkgname);
2354         if (len == 0) {
2355             if (level > 0) {
2356                 PyErr_SetString(PyExc_ValueError,
2357                     "Attempted relative import in non-package");
2358                 return NULL;
2359             }
2360             return Py_None;
2361         }
2362         if (len > MAXPATHLEN) {
2363             PyErr_SetString(PyExc_ValueError,
2364                             "Package name too long");
2365             return NULL;
2366         }
2367         strcpy(buf, PyString_AS_STRING(pkgname));
2368     } else {
2369         /* __package__ not set, so figure it out and set it */
2370         modname = PyDict_GetItem(globals, namestr);
2371         if (modname == NULL || !PyString_Check(modname))
2372             return Py_None;
2373 
2374         modpath = PyDict_GetItem(globals, pathstr);
2375         if (modpath != NULL) {
2376             /* __path__ is set, so modname is already the package name */
2377             Py_ssize_t len = PyString_GET_SIZE(modname);
2378             int error;
2379             if (len > MAXPATHLEN) {
2380                 PyErr_SetString(PyExc_ValueError,
2381                                 "Module name too long");
2382                 return NULL;
2383             }
2384             strcpy(buf, PyString_AS_STRING(modname));
2385             error = PyDict_SetItem(globals, pkgstr, modname);
2386             if (error) {
2387                 PyErr_SetString(PyExc_ValueError,
2388                                 "Could not set __package__");
2389                 return NULL;
2390             }
2391         } else {
2392             /* Normal module, so work out the package name if any */
2393             char *start = PyString_AS_STRING(modname);
2394             char *lastdot = strrchr(start, '.');
2395             size_t len;
2396             int error;
2397             if (lastdot == NULL && level > 0) {
2398                 PyErr_SetString(PyExc_ValueError,
2399                     "Attempted relative import in non-package");
2400                 return NULL;
2401             }
2402             if (lastdot == NULL) {
2403                 error = PyDict_SetItem(globals, pkgstr, Py_None);
2404                 if (error) {
2405                     PyErr_SetString(PyExc_ValueError,
2406                         "Could not set __package__");
2407                     return NULL;
2408                 }
2409                 return Py_None;
2410             }
2411             len = lastdot - start;
2412             if (len >= MAXPATHLEN) {
2413                 PyErr_SetString(PyExc_ValueError,
2414                                 "Module name too long");
2415                 return NULL;
2416             }
2417             strncpy(buf, start, len);
2418             buf[len] = '\0';
2419             pkgname = PyString_FromString(buf);
2420             if (pkgname == NULL) {
2421                 return NULL;
2422             }
2423             error = PyDict_SetItem(globals, pkgstr, pkgname);
2424             Py_DECREF(pkgname);
2425             if (error) {
2426                 PyErr_SetString(PyExc_ValueError,
2427                                 "Could not set __package__");
2428                 return NULL;
2429             }
2430         }
2431     }
2432     while (--level > 0) {
2433         char *dot = strrchr(buf, '.');
2434         if (dot == NULL) {
2435             PyErr_SetString(PyExc_ValueError,
2436                 "Attempted relative import beyond "
2437                 "toplevel package");
2438             return NULL;
2439         }
2440         *dot = '\0';
2441     }
2442     *p_buflen = strlen(buf);
2443 
2444     modules = PyImport_GetModuleDict();
2445     parent = PyDict_GetItemString(modules, buf);
2446     if (parent == NULL) {
2447         if (orig_level < 1) {
2448             PyObject *err_msg = PyString_FromFormat(
2449                 "Parent module '%.200s' not found "
2450                 "while handling absolute import", buf);
2451             if (err_msg == NULL) {
2452                 return NULL;
2453             }
2454             if (!PyErr_WarnEx(PyExc_RuntimeWarning,
2455                             PyString_AsString(err_msg), 1)) {
2456                 *buf = '\0';
2457                 *p_buflen = 0;
2458                 parent = Py_None;
2459             }
2460             Py_DECREF(err_msg);
2461         } else {
2462             PyErr_Format(PyExc_SystemError,
2463                 "Parent module '%.200s' not loaded, "
2464                 "cannot perform relative import", buf);
2465         }
2466     }
2467     return parent;
2468     /* We expect, but can't guarantee, if parent != None, that:
2469        - parent.__name__ == buf
2470        - parent.__dict__ is globals
2471        If this is violated...  Who cares? */
2472 }
2473 
2474 /* altmod is either None or same as mod */
2475 static PyObject *
load_next(PyObject * mod,PyObject * altmod,char ** p_name,char * buf,Py_ssize_t * p_buflen)2476 load_next(PyObject *mod, PyObject *altmod, char **p_name, char *buf,
2477           Py_ssize_t *p_buflen)
2478 {
2479     char *name = *p_name;
2480     char *dot = strchr(name, '.');
2481     size_t len;
2482     char *p;
2483     PyObject *result;
2484 
2485     if (strlen(name) == 0) {
2486         /* completely empty module name should only happen in
2487            'from . import' (or '__import__("")')*/
2488         Py_INCREF(mod);
2489         *p_name = NULL;
2490         return mod;
2491     }
2492 
2493     if (dot == NULL) {
2494         *p_name = NULL;
2495         len = strlen(name);
2496     }
2497     else {
2498         *p_name = dot+1;
2499         len = dot-name;
2500     }
2501     if (len == 0) {
2502         PyErr_SetString(PyExc_ValueError,
2503                         "Empty module name");
2504         return NULL;
2505     }
2506 
2507     p = buf + *p_buflen;
2508     if (p != buf)
2509         *p++ = '.';
2510     if (p+len-buf >= MAXPATHLEN) {
2511         PyErr_SetString(PyExc_ValueError,
2512                         "Module name too long");
2513         return NULL;
2514     }
2515     strncpy(p, name, len);
2516     p[len] = '\0';
2517     *p_buflen = p+len-buf;
2518 
2519     result = import_submodule(mod, p, buf);
2520     if (result == Py_None && altmod != mod) {
2521         Py_DECREF(result);
2522         /* Here, altmod must be None and mod must not be None */
2523         result = import_submodule(altmod, p, p);
2524         if (result != NULL && result != Py_None) {
2525             if (mark_miss(buf) != 0) {
2526                 Py_DECREF(result);
2527                 return NULL;
2528             }
2529             strncpy(buf, name, len);
2530             buf[len] = '\0';
2531             *p_buflen = len;
2532         }
2533     }
2534     if (result == NULL)
2535         return NULL;
2536 
2537     if (result == Py_None) {
2538         Py_DECREF(result);
2539         PyErr_Format(PyExc_ImportError,
2540                      "No module named %.200s", name);
2541         return NULL;
2542     }
2543 
2544     return result;
2545 }
2546 
2547 static int
mark_miss(char * name)2548 mark_miss(char *name)
2549 {
2550     PyObject *modules = PyImport_GetModuleDict();
2551     return PyDict_SetItemString(modules, name, Py_None);
2552 }
2553 
2554 static int
ensure_fromlist(PyObject * mod,PyObject * fromlist,char * buf,Py_ssize_t buflen,int recursive)2555 ensure_fromlist(PyObject *mod, PyObject *fromlist, char *buf, Py_ssize_t buflen,
2556                 int recursive)
2557 {
2558     int i;
2559 
2560     if (!PyObject_HasAttrString(mod, "__path__"))
2561         return 1;
2562 
2563     for (i = 0; ; i++) {
2564         PyObject *item = PySequence_GetItem(fromlist, i);
2565         int hasit;
2566         if (item == NULL) {
2567             if (PyErr_ExceptionMatches(PyExc_IndexError)) {
2568                 PyErr_Clear();
2569                 return 1;
2570             }
2571             return 0;
2572         }
2573         if (!PyString_Check(item)) {
2574             PyErr_SetString(PyExc_TypeError,
2575                             "Item in ``from list'' not a string");
2576             Py_DECREF(item);
2577             return 0;
2578         }
2579         if (PyString_AS_STRING(item)[0] == '*') {
2580             PyObject *all;
2581             Py_DECREF(item);
2582             /* See if the package defines __all__ */
2583             if (recursive)
2584                 continue; /* Avoid endless recursion */
2585             all = PyObject_GetAttrString(mod, "__all__");
2586             if (all == NULL)
2587                 PyErr_Clear();
2588             else {
2589                 int ret = ensure_fromlist(mod, all, buf, buflen, 1);
2590                 Py_DECREF(all);
2591                 if (!ret)
2592                     return 0;
2593             }
2594             continue;
2595         }
2596         hasit = PyObject_HasAttr(mod, item);
2597         if (!hasit) {
2598             char *subname = PyString_AS_STRING(item);
2599             PyObject *submod;
2600             char *p;
2601             if (buflen + strlen(subname) >= MAXPATHLEN) {
2602                 PyErr_SetString(PyExc_ValueError,
2603                                 "Module name too long");
2604                 Py_DECREF(item);
2605                 return 0;
2606             }
2607             p = buf + buflen;
2608             *p++ = '.';
2609             strcpy(p, subname);
2610             submod = import_submodule(mod, subname, buf);
2611             Py_XDECREF(submod);
2612             if (submod == NULL) {
2613                 Py_DECREF(item);
2614                 return 0;
2615             }
2616         }
2617         Py_DECREF(item);
2618     }
2619 
2620     /* NOTREACHED */
2621 }
2622 
2623 static int
add_submodule(PyObject * mod,PyObject * submod,char * fullname,char * subname,PyObject * modules)2624 add_submodule(PyObject *mod, PyObject *submod, char *fullname, char *subname,
2625               PyObject *modules)
2626 {
2627     if (mod == Py_None)
2628         return 1;
2629     /* Irrespective of the success of this load, make a
2630        reference to it in the parent package module.  A copy gets
2631        saved in the modules dictionary under the full name, so get a
2632        reference from there, if need be.  (The exception is when the
2633        load failed with a SyntaxError -- then there's no trace in
2634        sys.modules.  In that case, of course, do nothing extra.) */
2635     if (submod == NULL) {
2636         submod = PyDict_GetItemString(modules, fullname);
2637         if (submod == NULL)
2638             return 1;
2639     }
2640     if (PyModule_Check(mod)) {
2641         /* We can't use setattr here since it can give a
2642          * spurious warning if the submodule name shadows a
2643          * builtin name */
2644         PyObject *dict = PyModule_GetDict(mod);
2645         if (!dict)
2646             return 0;
2647         if (PyDict_SetItemString(dict, subname, submod) < 0)
2648             return 0;
2649     }
2650     else {
2651         if (PyObject_SetAttrString(mod, subname, submod) < 0)
2652             return 0;
2653     }
2654     return 1;
2655 }
2656 
2657 static PyObject *
import_submodule(PyObject * mod,char * subname,char * fullname)2658 import_submodule(PyObject *mod, char *subname, char *fullname)
2659 {
2660     PyObject *modules = PyImport_GetModuleDict();
2661     PyObject *m = NULL;
2662 
2663     /* Require:
2664        if mod == None: subname == fullname
2665        else: mod.__name__ + "." + subname == fullname
2666     */
2667 
2668     if ((m = PyDict_GetItemString(modules, fullname)) != NULL) {
2669         Py_INCREF(m);
2670     }
2671     else {
2672         PyObject *path, *loader = NULL;
2673         char *buf;
2674         struct filedescr *fdp;
2675         FILE *fp = NULL;
2676 
2677         if (mod == Py_None)
2678             path = NULL;
2679         else {
2680             path = PyObject_GetAttrString(mod, "__path__");
2681             if (path == NULL) {
2682                 PyErr_Clear();
2683                 Py_INCREF(Py_None);
2684                 return Py_None;
2685             }
2686         }
2687 
2688         buf = PyMem_MALLOC(MAXPATHLEN+1);
2689         if (buf == NULL) {
2690             return PyErr_NoMemory();
2691         }
2692         buf[0] = '\0';
2693         fdp = find_module(fullname, subname, path, buf, MAXPATHLEN+1,
2694                           &fp, &loader);
2695         Py_XDECREF(path);
2696         if (fdp == NULL) {
2697             PyMem_FREE(buf);
2698             if (!PyErr_ExceptionMatches(PyExc_ImportError))
2699                 return NULL;
2700             PyErr_Clear();
2701             Py_INCREF(Py_None);
2702             return Py_None;
2703         }
2704         m = load_module(fullname, fp, buf, fdp->type, loader);
2705         Py_XDECREF(loader);
2706         if (fp)
2707             fclose(fp);
2708         if (!add_submodule(mod, m, fullname, subname, modules)) {
2709             Py_XDECREF(m);
2710             m = NULL;
2711         }
2712         PyMem_FREE(buf);
2713     }
2714 
2715     return m;
2716 }
2717 
2718 
2719 /* Re-import a module of any kind and return its module object, WITH
2720    INCREMENTED REFERENCE COUNT */
2721 
2722 PyObject *
PyImport_ReloadModule(PyObject * m)2723 PyImport_ReloadModule(PyObject *m)
2724 {
2725     PyInterpreterState *interp = PyThreadState_Get()->interp;
2726     PyObject *modules_reloading = interp->modules_reloading;
2727     PyObject *modules = PyImport_GetModuleDict();
2728     PyObject *path = NULL, *loader = NULL, *existing_m = NULL;
2729     char *name, *subname;
2730     char *buf;
2731     struct filedescr *fdp;
2732     FILE *fp = NULL;
2733     PyObject *newm;
2734 
2735     if (modules_reloading == NULL) {
2736         Py_FatalError("PyImport_ReloadModule: "
2737                       "no modules_reloading dictionary!");
2738         return NULL;
2739     }
2740 
2741     if (m == NULL || !PyModule_Check(m)) {
2742         PyErr_SetString(PyExc_TypeError,
2743                         "reload() argument must be module");
2744         return NULL;
2745     }
2746     name = PyModule_GetName(m);
2747     if (name == NULL)
2748         return NULL;
2749     if (m != PyDict_GetItemString(modules, name)) {
2750         PyErr_Format(PyExc_ImportError,
2751                      "reload(): module %.200s not in sys.modules",
2752                      name);
2753         return NULL;
2754     }
2755     existing_m = PyDict_GetItemString(modules_reloading, name);
2756     if (existing_m != NULL) {
2757         /* Due to a recursive reload, this module is already
2758            being reloaded. */
2759         Py_INCREF(existing_m);
2760         return existing_m;
2761     }
2762     if (PyDict_SetItemString(modules_reloading, name, m) < 0)
2763         return NULL;
2764 
2765     subname = strrchr(name, '.');
2766     if (subname == NULL)
2767         subname = name;
2768     else {
2769         PyObject *parentname, *parent;
2770         parentname = PyString_FromStringAndSize(name, (subname-name));
2771         if (parentname == NULL) {
2772             imp_modules_reloading_clear();
2773             return NULL;
2774         }
2775         parent = PyDict_GetItem(modules, parentname);
2776         if (parent == NULL) {
2777             PyErr_Format(PyExc_ImportError,
2778                 "reload(): parent %.200s not in sys.modules",
2779                 PyString_AS_STRING(parentname));
2780             Py_DECREF(parentname);
2781             imp_modules_reloading_clear();
2782             return NULL;
2783         }
2784         Py_DECREF(parentname);
2785         subname++;
2786         path = PyObject_GetAttrString(parent, "__path__");
2787         if (path == NULL)
2788             PyErr_Clear();
2789     }
2790     buf = PyMem_MALLOC(MAXPATHLEN+1);
2791     if (buf == NULL) {
2792         Py_XDECREF(path);
2793         return PyErr_NoMemory();
2794     }
2795     buf[0] = '\0';
2796     fdp = find_module(name, subname, path, buf, MAXPATHLEN+1, &fp, &loader);
2797     Py_XDECREF(path);
2798 
2799     if (fdp == NULL) {
2800         Py_XDECREF(loader);
2801         imp_modules_reloading_clear();
2802         PyMem_FREE(buf);
2803         return NULL;
2804     }
2805 
2806     newm = load_module(name, fp, buf, fdp->type, loader);
2807     Py_XDECREF(loader);
2808 
2809     if (fp)
2810         fclose(fp);
2811     if (newm == NULL) {
2812         /* load_module probably removed name from modules because of
2813          * the error.  Put back the original module object.  We're
2814          * going to return NULL in this case regardless of whether
2815          * replacing name succeeds, so the return value is ignored.
2816          */
2817         PyDict_SetItemString(modules, name, m);
2818     }
2819     imp_modules_reloading_clear();
2820     PyMem_FREE(buf);
2821     return newm;
2822 }
2823 
2824 
2825 /* Higher-level import emulator which emulates the "import" statement
2826    more accurately -- it invokes the __import__() function from the
2827    builtins of the current globals.  This means that the import is
2828    done using whatever import hooks are installed in the current
2829    environment, e.g. by "rexec".
2830    A dummy list ["__doc__"] is passed as the 4th argument so that
2831    e.g. PyImport_Import(PyString_FromString("win32com.client.gencache"))
2832    will return <module "gencache"> instead of <module "win32com">. */
2833 
2834 PyObject *
PyImport_Import(PyObject * module_name)2835 PyImport_Import(PyObject *module_name)
2836 {
2837     static PyObject *silly_list = NULL;
2838     static PyObject *builtins_str = NULL;
2839     static PyObject *import_str = NULL;
2840     PyObject *globals = NULL;
2841     PyObject *import = NULL;
2842     PyObject *builtins = NULL;
2843     PyObject *r = NULL;
2844 
2845     /* Initialize constant string objects */
2846     if (silly_list == NULL) {
2847         import_str = PyString_InternFromString("__import__");
2848         if (import_str == NULL)
2849             return NULL;
2850         builtins_str = PyString_InternFromString("__builtins__");
2851         if (builtins_str == NULL)
2852             return NULL;
2853         silly_list = Py_BuildValue("[s]", "__doc__");
2854         if (silly_list == NULL)
2855             return NULL;
2856     }
2857 
2858     /* Get the builtins from current globals */
2859     globals = PyEval_GetGlobals();
2860     if (globals != NULL) {
2861         Py_INCREF(globals);
2862         builtins = PyObject_GetItem(globals, builtins_str);
2863         if (builtins == NULL)
2864             goto err;
2865     }
2866     else {
2867         /* No globals -- use standard builtins, and fake globals */
2868         builtins = PyImport_ImportModuleLevel("__builtin__",
2869                                               NULL, NULL, NULL, 0);
2870         if (builtins == NULL)
2871             return NULL;
2872         globals = Py_BuildValue("{OO}", builtins_str, builtins);
2873         if (globals == NULL)
2874             goto err;
2875     }
2876 
2877     /* Get the __import__ function from the builtins */
2878     if (PyDict_Check(builtins)) {
2879         import = PyObject_GetItem(builtins, import_str);
2880         if (import == NULL)
2881             PyErr_SetObject(PyExc_KeyError, import_str);
2882     }
2883     else
2884         import = PyObject_GetAttr(builtins, import_str);
2885     if (import == NULL)
2886         goto err;
2887 
2888     /* Call the __import__ function with the proper argument list
2889      * Always use absolute import here. */
2890     r = PyObject_CallFunction(import, "OOOOi", module_name, globals,
2891                               globals, silly_list, 0, NULL);
2892 
2893   err:
2894     Py_XDECREF(globals);
2895     Py_XDECREF(builtins);
2896     Py_XDECREF(import);
2897 
2898     return r;
2899 }
2900 
2901 
2902 /* Module 'imp' provides Python access to the primitives used for
2903    importing modules.
2904 */
2905 
2906 static PyObject *
imp_get_magic(PyObject * self,PyObject * noargs)2907 imp_get_magic(PyObject *self, PyObject *noargs)
2908 {
2909     char buf[4];
2910 
2911     buf[0] = (char) ((pyc_magic >>  0) & 0xff);
2912     buf[1] = (char) ((pyc_magic >>  8) & 0xff);
2913     buf[2] = (char) ((pyc_magic >> 16) & 0xff);
2914     buf[3] = (char) ((pyc_magic >> 24) & 0xff);
2915 
2916     return PyString_FromStringAndSize(buf, 4);
2917 }
2918 
2919 static PyObject *
imp_get_suffixes(PyObject * self,PyObject * noargs)2920 imp_get_suffixes(PyObject *self, PyObject *noargs)
2921 {
2922     PyObject *list;
2923     struct filedescr *fdp;
2924 
2925     list = PyList_New(0);
2926     if (list == NULL)
2927         return NULL;
2928     for (fdp = _PyImport_Filetab; fdp->suffix != NULL; fdp++) {
2929         PyObject *item = Py_BuildValue("ssi",
2930                                fdp->suffix, fdp->mode, fdp->type);
2931         if (item == NULL) {
2932             Py_DECREF(list);
2933             return NULL;
2934         }
2935         if (PyList_Append(list, item) < 0) {
2936             Py_DECREF(list);
2937             Py_DECREF(item);
2938             return NULL;
2939         }
2940         Py_DECREF(item);
2941     }
2942     return list;
2943 }
2944 
2945 static PyObject *
call_find_module(char * name,PyObject * path)2946 call_find_module(char *name, PyObject *path)
2947 {
2948     extern int fclose(FILE *);
2949     PyObject *fob, *ret;
2950     struct filedescr *fdp;
2951     char *pathname;
2952     FILE *fp = NULL;
2953 
2954     pathname = PyMem_MALLOC(MAXPATHLEN+1);
2955     if (pathname == NULL) {
2956         return PyErr_NoMemory();
2957     }
2958     pathname[0] = '\0';
2959     if (path == Py_None)
2960         path = NULL;
2961     fdp = find_module(NULL, name, path, pathname, MAXPATHLEN+1, &fp, NULL);
2962     if (fdp == NULL) {
2963         PyMem_FREE(pathname);
2964         return NULL;
2965     }
2966     if (fp != NULL) {
2967         fob = PyFile_FromFile(fp, pathname, fdp->mode, fclose);
2968         if (fob == NULL) {
2969             PyMem_FREE(pathname);
2970             return NULL;
2971         }
2972     }
2973     else {
2974         fob = Py_None;
2975         Py_INCREF(fob);
2976     }
2977     ret = Py_BuildValue("Os(ssi)",
2978                   fob, pathname, fdp->suffix, fdp->mode, fdp->type);
2979     Py_DECREF(fob);
2980     PyMem_FREE(pathname);
2981     return ret;
2982 }
2983 
2984 static PyObject *
imp_find_module(PyObject * self,PyObject * args)2985 imp_find_module(PyObject *self, PyObject *args)
2986 {
2987     char *name;
2988     PyObject *path = NULL;
2989     if (!PyArg_ParseTuple(args, "s|O:find_module", &name, &path))
2990         return NULL;
2991     return call_find_module(name, path);
2992 }
2993 
2994 static PyObject *
imp_init_builtin(PyObject * self,PyObject * args)2995 imp_init_builtin(PyObject *self, PyObject *args)
2996 {
2997     char *name;
2998     int ret;
2999     PyObject *m;
3000     if (!PyArg_ParseTuple(args, "s:init_builtin", &name))
3001         return NULL;
3002     ret = init_builtin(name);
3003     if (ret < 0)
3004         return NULL;
3005     if (ret == 0) {
3006         Py_INCREF(Py_None);
3007         return Py_None;
3008     }
3009     m = PyImport_AddModule(name);
3010     Py_XINCREF(m);
3011     return m;
3012 }
3013 
3014 static PyObject *
imp_init_frozen(PyObject * self,PyObject * args)3015 imp_init_frozen(PyObject *self, PyObject *args)
3016 {
3017     char *name;
3018     int ret;
3019     PyObject *m;
3020     if (!PyArg_ParseTuple(args, "s:init_frozen", &name))
3021         return NULL;
3022     ret = PyImport_ImportFrozenModule(name);
3023     if (ret < 0)
3024         return NULL;
3025     if (ret == 0) {
3026         Py_INCREF(Py_None);
3027         return Py_None;
3028     }
3029     m = PyImport_AddModule(name);
3030     Py_XINCREF(m);
3031     return m;
3032 }
3033 
3034 static PyObject *
imp_get_frozen_object(PyObject * self,PyObject * args)3035 imp_get_frozen_object(PyObject *self, PyObject *args)
3036 {
3037     char *name;
3038 
3039     if (!PyArg_ParseTuple(args, "s:get_frozen_object", &name))
3040         return NULL;
3041     return get_frozen_object(name);
3042 }
3043 
3044 static PyObject *
imp_is_builtin(PyObject * self,PyObject * args)3045 imp_is_builtin(PyObject *self, PyObject *args)
3046 {
3047     char *name;
3048     if (!PyArg_ParseTuple(args, "s:is_builtin", &name))
3049         return NULL;
3050     return PyInt_FromLong(is_builtin(name));
3051 }
3052 
3053 static PyObject *
imp_is_frozen(PyObject * self,PyObject * args)3054 imp_is_frozen(PyObject *self, PyObject *args)
3055 {
3056     char *name;
3057     struct _frozen *p;
3058     if (!PyArg_ParseTuple(args, "s:is_frozen", &name))
3059         return NULL;
3060     p = find_frozen(name);
3061     return PyBool_FromLong((long) (p == NULL ? 0 : p->size));
3062 }
3063 
3064 static FILE *
get_file(char * pathname,PyObject * fob,char * mode)3065 get_file(char *pathname, PyObject *fob, char *mode)
3066 {
3067     FILE *fp;
3068     if (fob == NULL) {
3069         if (mode[0] == 'U')
3070             mode = "r" PY_STDIOTEXTMODE;
3071         fp = fopen(pathname, mode);
3072         if (fp == NULL)
3073             PyErr_SetFromErrno(PyExc_IOError);
3074     }
3075     else {
3076         fp = PyFile_AsFile(fob);
3077         if (fp == NULL)
3078             PyErr_SetString(PyExc_ValueError,
3079                             "bad/closed file object");
3080     }
3081     return fp;
3082 }
3083 
3084 static PyObject *
imp_load_compiled(PyObject * self,PyObject * args)3085 imp_load_compiled(PyObject *self, PyObject *args)
3086 {
3087     char *name;
3088     char *pathname;
3089     PyObject *fob = NULL;
3090     PyObject *m;
3091     FILE *fp;
3092     if (!PyArg_ParseTuple(args, "ss|O!:load_compiled", &name, &pathname,
3093                           &PyFile_Type, &fob))
3094         return NULL;
3095     fp = get_file(pathname, fob, "rb");
3096     if (fp == NULL)
3097         return NULL;
3098     m = load_compiled_module(name, pathname, fp);
3099     if (fob == NULL)
3100         fclose(fp);
3101     return m;
3102 }
3103 
3104 #ifdef HAVE_DYNAMIC_LOADING
3105 
3106 static PyObject *
imp_load_dynamic(PyObject * self,PyObject * args)3107 imp_load_dynamic(PyObject *self, PyObject *args)
3108 {
3109     char *name;
3110     char *pathname;
3111     PyObject *fob = NULL;
3112     PyObject *m;
3113     FILE *fp = NULL;
3114     if (!PyArg_ParseTuple(args, "ss|O!:load_dynamic", &name, &pathname,
3115                           &PyFile_Type, &fob))
3116         return NULL;
3117     if (fob) {
3118         fp = get_file(pathname, fob, "r");
3119         if (fp == NULL)
3120             return NULL;
3121     }
3122     m = _PyImport_LoadDynamicModule(name, pathname, fp);
3123     return m;
3124 }
3125 
3126 #endif /* HAVE_DYNAMIC_LOADING */
3127 
3128 static PyObject *
imp_load_source(PyObject * self,PyObject * args)3129 imp_load_source(PyObject *self, PyObject *args)
3130 {
3131     char *name;
3132     char *pathname;
3133     PyObject *fob = NULL;
3134     PyObject *m;
3135     FILE *fp;
3136     if (!PyArg_ParseTuple(args, "ss|O!:load_source", &name, &pathname,
3137                           &PyFile_Type, &fob))
3138         return NULL;
3139     fp = get_file(pathname, fob, "r");
3140     if (fp == NULL)
3141         return NULL;
3142     m = load_source_module(name, pathname, fp);
3143     if (fob == NULL)
3144         fclose(fp);
3145     return m;
3146 }
3147 
3148 static PyObject *
imp_load_module(PyObject * self,PyObject * args)3149 imp_load_module(PyObject *self, PyObject *args)
3150 {
3151     char *name;
3152     PyObject *fob;
3153     char *pathname;
3154     char *suffix; /* Unused */
3155     char *mode;
3156     int type;
3157     FILE *fp;
3158 
3159     if (!PyArg_ParseTuple(args, "sOs(ssi):load_module",
3160                           &name, &fob, &pathname,
3161                           &suffix, &mode, &type))
3162         return NULL;
3163     if (*mode) {
3164         /* Mode must start with 'r' or 'U' and must not contain '+'.
3165            Implicit in this test is the assumption that the mode
3166            may contain other modifiers like 'b' or 't'. */
3167 
3168         if (!(*mode == 'r' || *mode == 'U') || strchr(mode, '+')) {
3169             PyErr_Format(PyExc_ValueError,
3170                          "invalid file open mode %.200s", mode);
3171             return NULL;
3172         }
3173     }
3174     if (fob == Py_None)
3175         fp = NULL;
3176     else {
3177         if (!PyFile_Check(fob)) {
3178             PyErr_SetString(PyExc_ValueError,
3179                 "load_module arg#2 should be a file or None");
3180             return NULL;
3181         }
3182         fp = get_file(pathname, fob, mode);
3183         if (fp == NULL)
3184             return NULL;
3185     }
3186     return load_module(name, fp, pathname, type, NULL);
3187 }
3188 
3189 static PyObject *
imp_load_package(PyObject * self,PyObject * args)3190 imp_load_package(PyObject *self, PyObject *args)
3191 {
3192     char *name;
3193     char *pathname;
3194     if (!PyArg_ParseTuple(args, "ss:load_package", &name, &pathname))
3195         return NULL;
3196     return load_package(name, pathname);
3197 }
3198 
3199 static PyObject *
imp_new_module(PyObject * self,PyObject * args)3200 imp_new_module(PyObject *self, PyObject *args)
3201 {
3202     char *name;
3203     if (!PyArg_ParseTuple(args, "s:new_module", &name))
3204         return NULL;
3205     return PyModule_New(name);
3206 }
3207 
3208 static PyObject *
imp_reload(PyObject * self,PyObject * v)3209 imp_reload(PyObject *self, PyObject *v)
3210 {
3211     return PyImport_ReloadModule(v);
3212 }
3213 
3214 
3215 /* Doc strings */
3216 
3217 PyDoc_STRVAR(doc_imp,
3218 "This module provides the components needed to build your own\n\
3219 __import__ function.  Undocumented functions are obsolete.");
3220 
3221 PyDoc_STRVAR(doc_reload,
3222 "reload(module) -> module\n\
3223 \n\
3224 Reload the module.  The module must have been successfully imported before.");
3225 
3226 PyDoc_STRVAR(doc_find_module,
3227 "find_module(name, [path]) -> (file, filename, (suffix, mode, type))\n\
3228 Search for a module.  If path is omitted or None, search for a\n\
3229 built-in, frozen or special module and continue search in sys.path.\n\
3230 The module name cannot contain '.'; to search for a submodule of a\n\
3231 package, pass the submodule name and the package's __path__.");
3232 
3233 PyDoc_STRVAR(doc_load_module,
3234 "load_module(name, file, filename, (suffix, mode, type)) -> module\n\
3235 Load a module, given information returned by find_module().\n\
3236 The module name must include the full package name, if any.");
3237 
3238 PyDoc_STRVAR(doc_get_magic,
3239 "get_magic() -> string\n\
3240 Return the magic number for .pyc or .pyo files.");
3241 
3242 PyDoc_STRVAR(doc_get_suffixes,
3243 "get_suffixes() -> [(suffix, mode, type), ...]\n\
3244 Return a list of (suffix, mode, type) tuples describing the files\n\
3245 that find_module() looks for.");
3246 
3247 PyDoc_STRVAR(doc_new_module,
3248 "new_module(name) -> module\n\
3249 Create a new module.  Do not enter it in sys.modules.\n\
3250 The module name must include the full package name, if any.");
3251 
3252 PyDoc_STRVAR(doc_lock_held,
3253 "lock_held() -> boolean\n\
3254 Return True if the import lock is currently held, else False.\n\
3255 On platforms without threads, return False.");
3256 
3257 PyDoc_STRVAR(doc_acquire_lock,
3258 "acquire_lock() -> None\n\
3259 Acquires the interpreter's import lock for the current thread.\n\
3260 This lock should be used by import hooks to ensure thread-safety\n\
3261 when importing modules.\n\
3262 On platforms without threads, this function does nothing.");
3263 
3264 PyDoc_STRVAR(doc_release_lock,
3265 "release_lock() -> None\n\
3266 Release the interpreter's import lock.\n\
3267 On platforms without threads, this function does nothing.");
3268 
3269 static PyMethodDef imp_methods[] = {
3270     {"reload",           imp_reload,       METH_O,       doc_reload},
3271     {"find_module",      imp_find_module,  METH_VARARGS, doc_find_module},
3272     {"get_magic",        imp_get_magic,    METH_NOARGS,  doc_get_magic},
3273     {"get_suffixes", imp_get_suffixes, METH_NOARGS,  doc_get_suffixes},
3274     {"load_module",      imp_load_module,  METH_VARARGS, doc_load_module},
3275     {"new_module",       imp_new_module,   METH_VARARGS, doc_new_module},
3276     {"lock_held",        imp_lock_held,    METH_NOARGS,  doc_lock_held},
3277     {"acquire_lock", imp_acquire_lock, METH_NOARGS,  doc_acquire_lock},
3278     {"release_lock", imp_release_lock, METH_NOARGS,  doc_release_lock},
3279     /* The rest are obsolete */
3280     {"get_frozen_object",       imp_get_frozen_object,  METH_VARARGS},
3281     {"init_builtin",            imp_init_builtin,       METH_VARARGS},
3282     {"init_frozen",             imp_init_frozen,        METH_VARARGS},
3283     {"is_builtin",              imp_is_builtin,         METH_VARARGS},
3284     {"is_frozen",               imp_is_frozen,          METH_VARARGS},
3285     {"load_compiled",           imp_load_compiled,      METH_VARARGS},
3286 #ifdef HAVE_DYNAMIC_LOADING
3287     {"load_dynamic",            imp_load_dynamic,       METH_VARARGS},
3288 #endif
3289     {"load_package",            imp_load_package,       METH_VARARGS},
3290     {"load_source",             imp_load_source,        METH_VARARGS},
3291     {NULL,                      NULL}           /* sentinel */
3292 };
3293 
3294 static int
setint(PyObject * d,char * name,int value)3295 setint(PyObject *d, char *name, int value)
3296 {
3297     PyObject *v;
3298     int err;
3299 
3300     v = PyInt_FromLong((long)value);
3301     err = PyDict_SetItemString(d, name, v);
3302     Py_XDECREF(v);
3303     return err;
3304 }
3305 
3306 typedef struct {
3307     PyObject_HEAD
3308 } NullImporter;
3309 
3310 static int
NullImporter_init(NullImporter * self,PyObject * args,PyObject * kwds)3311 NullImporter_init(NullImporter *self, PyObject *args, PyObject *kwds)
3312 {
3313     char *path;
3314     Py_ssize_t pathlen;
3315 
3316     if (!_PyArg_NoKeywords("NullImporter()", kwds))
3317         return -1;
3318 
3319     if (!PyArg_ParseTuple(args, "s:NullImporter",
3320                           &path))
3321         return -1;
3322 
3323     pathlen = strlen(path);
3324     if (pathlen == 0) {
3325         PyErr_SetString(PyExc_ImportError, "empty pathname");
3326         return -1;
3327     } else {
3328         if(isdir(path)) {
3329             PyErr_SetString(PyExc_ImportError,
3330                             "existing directory");
3331             return -1;
3332         }
3333     }
3334     return 0;
3335 }
3336 
3337 static PyObject *
NullImporter_find_module(NullImporter * self,PyObject * args)3338 NullImporter_find_module(NullImporter *self, PyObject *args)
3339 {
3340     Py_RETURN_NONE;
3341 }
3342 
3343 static PyMethodDef NullImporter_methods[] = {
3344     {"find_module", (PyCFunction)NullImporter_find_module, METH_VARARGS,
3345      "Always return None"
3346     },
3347     {NULL}  /* Sentinel */
3348 };
3349 
3350 
3351 PyTypeObject PyNullImporter_Type = {
3352     PyVarObject_HEAD_INIT(NULL, 0)
3353     "imp.NullImporter",        /*tp_name*/
3354     sizeof(NullImporter),      /*tp_basicsize*/
3355     0,                         /*tp_itemsize*/
3356     0,                         /*tp_dealloc*/
3357     0,                         /*tp_print*/
3358     0,                         /*tp_getattr*/
3359     0,                         /*tp_setattr*/
3360     0,                         /*tp_compare*/
3361     0,                         /*tp_repr*/
3362     0,                         /*tp_as_number*/
3363     0,                         /*tp_as_sequence*/
3364     0,                         /*tp_as_mapping*/
3365     0,                         /*tp_hash */
3366     0,                         /*tp_call*/
3367     0,                         /*tp_str*/
3368     0,                         /*tp_getattro*/
3369     0,                         /*tp_setattro*/
3370     0,                         /*tp_as_buffer*/
3371     Py_TPFLAGS_DEFAULT,        /*tp_flags*/
3372     "Null importer object",    /* tp_doc */
3373     0,                             /* tp_traverse */
3374     0,                             /* tp_clear */
3375     0,                             /* tp_richcompare */
3376     0,                             /* tp_weaklistoffset */
3377     0,                             /* tp_iter */
3378     0,                             /* tp_iternext */
3379     NullImporter_methods,      /* tp_methods */
3380     0,                         /* tp_members */
3381     0,                         /* tp_getset */
3382     0,                         /* tp_base */
3383     0,                         /* tp_dict */
3384     0,                         /* tp_descr_get */
3385     0,                         /* tp_descr_set */
3386     0,                         /* tp_dictoffset */
3387     (initproc)NullImporter_init,      /* tp_init */
3388     0,                         /* tp_alloc */
3389     PyType_GenericNew          /* tp_new */
3390 };
3391 
3392 
3393 PyMODINIT_FUNC
initimp(void)3394 initimp(void)
3395 {
3396     PyObject *m, *d;
3397 
3398     if (PyType_Ready(&PyNullImporter_Type) < 0)
3399         goto failure;
3400 
3401     m = Py_InitModule4("imp", imp_methods, doc_imp,
3402                        NULL, PYTHON_API_VERSION);
3403     if (m == NULL)
3404         goto failure;
3405     d = PyModule_GetDict(m);
3406     if (d == NULL)
3407         goto failure;
3408 
3409     if (setint(d, "SEARCH_ERROR", SEARCH_ERROR) < 0) goto failure;
3410     if (setint(d, "PY_SOURCE", PY_SOURCE) < 0) goto failure;
3411     if (setint(d, "PY_COMPILED", PY_COMPILED) < 0) goto failure;
3412     if (setint(d, "C_EXTENSION", C_EXTENSION) < 0) goto failure;
3413     if (setint(d, "PY_RESOURCE", PY_RESOURCE) < 0) goto failure;
3414     if (setint(d, "PKG_DIRECTORY", PKG_DIRECTORY) < 0) goto failure;
3415     if (setint(d, "C_BUILTIN", C_BUILTIN) < 0) goto failure;
3416     if (setint(d, "PY_FROZEN", PY_FROZEN) < 0) goto failure;
3417     if (setint(d, "PY_CODERESOURCE", PY_CODERESOURCE) < 0) goto failure;
3418     if (setint(d, "IMP_HOOK", IMP_HOOK) < 0) goto failure;
3419 
3420     Py_INCREF(&PyNullImporter_Type);
3421     PyModule_AddObject(m, "NullImporter", (PyObject *)&PyNullImporter_Type);
3422   failure:
3423     ;
3424 }
3425 
3426 
3427 /* API for embedding applications that want to add their own entries
3428    to the table of built-in modules.  This should normally be called
3429    *before* Py_Initialize().  When the table resize fails, -1 is
3430    returned and the existing table is unchanged.
3431 
3432    After a similar function by Just van Rossum. */
3433 
3434 int
PyImport_ExtendInittab(struct _inittab * newtab)3435 PyImport_ExtendInittab(struct _inittab *newtab)
3436 {
3437     static struct _inittab *our_copy = NULL;
3438     struct _inittab *p;
3439     int i, n;
3440 
3441     /* Count the number of entries in both tables */
3442     for (n = 0; newtab[n].name != NULL; n++)
3443         ;
3444     if (n == 0)
3445         return 0; /* Nothing to do */
3446     for (i = 0; PyImport_Inittab[i].name != NULL; i++)
3447         ;
3448 
3449     /* Allocate new memory for the combined table */
3450     p = our_copy;
3451     PyMem_RESIZE(p, struct _inittab, i+n+1);
3452     if (p == NULL)
3453         return -1;
3454 
3455     /* Copy the tables into the new memory */
3456     if (our_copy != PyImport_Inittab)
3457         memcpy(p, PyImport_Inittab, (i+1) * sizeof(struct _inittab));
3458     PyImport_Inittab = our_copy = p;
3459     memcpy(p+i, newtab, (n+1) * sizeof(struct _inittab));
3460 
3461     return 0;
3462 }
3463 
3464 /* Shorthand to add a single entry given a name and a function */
3465 
3466 int
PyImport_AppendInittab(const char * name,void (* initfunc)(void))3467 PyImport_AppendInittab(const char *name, void (*initfunc)(void))
3468 {
3469     struct _inittab newtab[2];
3470 
3471     memset(newtab, '\0', sizeof newtab);
3472 
3473     newtab[0].name = (char *)name;
3474     newtab[0].initfunc = initfunc;
3475 
3476     return PyImport_ExtendInittab(newtab);
3477 }
3478 
3479 #ifdef __cplusplus
3480 }
3481 #endif
3482