/* Module definition and import implementation */

#include "Python.h"

#include "Python-ast.h"

#undef Yield /* undefine macro conflicting with winbase.h */

#include "errcode.h"

#include "marshal.h"

#include "code.h"

#include "frameobject.h"

#include "osdefs.h"

#include "importdl.h"

#ifdef HAVE_FCNTL_H

#include <fcntl.h>

#endif

#ifdef __cplusplus

extern "C" {

#endif

#ifdef MS_WINDOWS

/* for stat.st_mode */

typedef unsigned short mode_t;

/* for _mkdir */

#include <direct.h>

#endif

#define CACHEDIR "__pycache__"

/* See _PyImport_FixupExtensionObject() below */

static PyObject *extensions = NULL;

/* Function from Parser/tokenizer.c */

extern char * PyTokenizer_FindEncodingFilename(int, PyObject *);

/* This table is defined in config.c: */

extern struct _inittab _PyImport_Inittab[];

struct _inittab *PyImport_Inittab = _PyImport_Inittab;

static PyObject *initstr = NULL;

/* Initialize things */

void

_PyImport_Init(void)

{

initstr = PyUnicode_InternFromString("__init__");

if (initstr == NULL)

Py_FatalError("Can't initialize import variables");

}

void

_PyImportHooks_Init(void)

{

PyObject *v, *path_hooks = NULL;

int err = 0;

/* adding sys.path_hooks and sys.path_importer_cache */

v = PyList_New(0);

if (v == NULL)

goto error;

err = PySys_SetObject("meta_path", v);

Py_DECREF(v);

if (err)

goto error;

v = PyDict_New();

if (v == NULL)

goto error;

err = PySys_SetObject("path_importer_cache", v);

Py_DECREF(v);

if (err)

goto error;

path_hooks = PyList_New(0);

if (path_hooks == NULL)

goto error;

err = PySys_SetObject("path_hooks", path_hooks);

if (err) {

error:

PyErr_Print();

Py_FatalError("initializing sys.meta_path, sys.path_hooks, "

"or path_importer_cache failed");

}

Py_DECREF(path_hooks);

}

void

_PyImportZip_Init(void)

{

PyObject *path_hooks, *zimpimport;

int err = 0;

path_hooks = PySys_GetObject("path_hooks");

if (path_hooks == NULL)

goto error;

if (Py_VerboseFlag)

PySys_WriteStderr("# installing zipimport hook\n");

zimpimport = PyImport_ImportModule("zipimport");

if (zimpimport == NULL) {

PyErr_Clear(); /* No zip import module -- okay */

if (Py_VerboseFlag)

PySys_WriteStderr("# can't import zipimport\n");

}

else {

_Py_IDENTIFIER(zipimporter);

PyObject *zipimporter = _PyObject_GetAttrId(zimpimport,

&PyId_zipimporter);

Py_DECREF(zimpimport);

if (zipimporter == NULL) {

PyErr_Clear(); /* No zipimporter object -- okay */

if (Py_VerboseFlag)

PySys_WriteStderr(

"# can't import zipimport.zipimporter\n");

}

else {

/* sys.path_hooks.insert(0, zipimporter) */

err = PyList_Insert(path_hooks, 0, zipimporter);

Py_DECREF(zipimporter);

if (err < 0) {

goto error;

}

if (Py_VerboseFlag)

PySys_WriteStderr(

"# installed zipimport hook\n");

}

}

return;

error:

PyErr_Print();

Py_FatalError("initializing zipimport failed");

}

/* Locking primitives to prevent parallel imports of the same module

in different threads to return with a partially loaded module.

These calls are serialized by the global interpreter lock. */

#ifdef WITH_THREAD

#include "pythread.h"

static PyThread_type_lock import_lock = 0;

static long import_lock_thread = -1;

static int import_lock_level = 0;

void

_PyImport_AcquireLock(void)

{

long me = PyThread_get_thread_ident();

if (me == -1)

return; /* Too bad */

if (import_lock == NULL) {

import_lock = PyThread_allocate_lock();

if (import_lock == NULL)

return; /* Nothing much we can do. */

}

if (import_lock_thread == me) {

import_lock_level++;

return;

}

if (import_lock_thread != -1 || !PyThread_acquire_lock(import_lock, 0))

{

PyThreadState *tstate = PyEval_SaveThread();

PyThread_acquire_lock(import_lock, 1);

PyEval_RestoreThread(tstate);

}

assert(import_lock_level == 0);

import_lock_thread = me;

import_lock_level = 1;

}

int

_PyImport_ReleaseLock(void)

{

long me = PyThread_get_thread_ident();

if (me == -1 || import_lock == NULL)

return 0; /* Too bad */

if (import_lock_thread != me)

return -1;

import_lock_level--;

assert(import_lock_level >= 0);

if (import_lock_level == 0) {

import_lock_thread = -1;

PyThread_release_lock(import_lock);

}

return 1;

}

/* This function is called from PyOS_AfterFork to ensure that newly

created child processes do not share locks with the parent.

We now acquire the import lock around fork() calls but on some platforms

(Solaris 9 and earlier? see isue7242) that still left us with problems. */

void

_PyImport_ReInitLock(void)

{

if (import_lock != NULL)

import_lock = PyThread_allocate_lock();

if (import_lock_level > 1) {

/* Forked as a side effect of import */

long me = PyThread_get_thread_ident();

/* The following could fail if the lock is already held, but forking as

a side-effect of an import is a) rare, b) nuts, and c) difficult to

do thanks to the lock only being held when doing individual module

locks per import. */

PyThread_acquire_lock(import_lock, NOWAIT_LOCK);

import_lock_thread = me;

import_lock_level--;

} else {

import_lock_thread = -1;

import_lock_level = 0;

}

}

#endif

static PyObject *

imp_lock_held(PyObject *self, PyObject *noargs)

{

#ifdef WITH_THREAD

return PyBool_FromLong(import_lock_thread != -1);

#else

return PyBool_FromLong(0);

#endif

}

static PyObject *

imp_acquire_lock(PyObject *self, PyObject *noargs)

{

#ifdef WITH_THREAD

_PyImport_AcquireLock();

#endif

Py_INCREF(Py_None);

return Py_None;

}

static PyObject *

imp_release_lock(PyObject *self, PyObject *noargs)

{

#ifdef WITH_THREAD

if (_PyImport_ReleaseLock() < 0) {

PyErr_SetString(PyExc_RuntimeError,

"not holding the import lock");

return NULL;

}

#endif

Py_INCREF(Py_None);

return Py_None;

}

void

_PyImport_Fini(void)

{

Py_XDECREF(extensions);

extensions = NULL;

#ifdef WITH_THREAD

if (import_lock != NULL) {

PyThread_free_lock(import_lock);

import_lock = NULL;

}

#endif

}

/* Helper for sys */

PyObject *

PyImport_GetModuleDict(void)

{

PyInterpreterState *interp = PyThreadState_GET()->interp;

if (interp->modules == NULL)

Py_FatalError("PyImport_GetModuleDict: no module dictionary!");

return interp->modules;

}

/* List of names to clear in sys */

static char* sys_deletes[] = {

"path", "argv", "ps1", "ps2",

"last_type", "last_value", "last_traceback",

"path_hooks", "path_importer_cache", "meta_path",

/* misc stuff */

"flags", "float_info",

NULL

};

static char* sys_files[] = {

"stdin", "__stdin__",

"stdout", "__stdout__",

"stderr", "__stderr__",

NULL

};

static int

is_essential_module(PyObject *name)

{

Py_ssize_t name_len;

char *name_str = PyUnicode_AsUTF8AndSize(name, &name_len);

if (name_str == NULL) {

PyErr_Clear();

return 0;

}

if (strcmp(name_str, "builtins") == 0)

return 1;

if (strcmp(name_str, "sys") == 0)

return 1;

/* These are all needed for stderr to still function */

if (strcmp(name_str, "codecs") == 0)

return 1;

if (strcmp(name_str, "_codecs") == 0)

return 1;

if (strncmp(name_str, "encodings.", 10) == 0)

return 1;

return 0;

}

/* Un-initialize things, as good as we can */

void

PyImport_Cleanup(void)

{

Py_ssize_t pos, ndone;

PyObject *key, *value, *dict;

PyInterpreterState *interp = PyThreadState_GET()->interp;

PyObject *modules = interp->modules;

if (modules == NULL)

return; /* Already done */

/* Delete some special variables first. These are common

places where user values hide and people complain when their

destructors fail. Since the modules containing them are

deleted *last* of all, they would come too late in the normal

destruction order. Sigh. */

value = PyDict_GetItemString(modules, "builtins");

if (value != NULL && PyModule_Check(value)) {

dict = PyModule_GetDict(value);

if (Py_VerboseFlag)

PySys_WriteStderr("# clear builtins._\n");

PyDict_SetItemString(dict, "_", Py_None);

}

value = PyDict_GetItemString(modules, "sys");

if (value != NULL && PyModule_Check(value)) {

char **p;

PyObject *v;

dict = PyModule_GetDict(value);

for (p = sys_deletes; *p != NULL; p++) {

if (Py_VerboseFlag)

PySys_WriteStderr("# clear sys.%s\n", *p);

PyDict_SetItemString(dict, *p, Py_None);

}

for (p = sys_files; *p != NULL; p+=2) {

if (Py_VerboseFlag)

PySys_WriteStderr("# restore sys.%s\n", *p);

v = PyDict_GetItemString(dict, *(p+1));

if (v == NULL)

v = Py_None;

PyDict_SetItemString(dict, *p, v);

}

}

/* First, delete __main__ */

value = PyDict_GetItemString(modules, "__main__");

if (value != NULL && PyModule_Check(value)) {

if (Py_VerboseFlag)

PySys_WriteStderr("# cleanup __main__\n");

_PyModule_Clear(value);

PyDict_SetItemString(modules, "__main__", Py_None);

}

/* The special treatment of "builtins" here is because even

when it's not referenced as a module, its dictionary is

referenced by almost every module's __builtins__. Since

deleting a module clears its dictionary (even if there are

references left to it), we need to delete the "builtins"

module last. Likewise, we don't delete sys until the very

end because it is implicitly referenced (e.g. by print).

Also note that we 'delete' modules by replacing their entry

in the modules dict with None, rather than really deleting

them; this avoids a rehash of the modules dictionary and

also marks them as "non existent" so they won't be

re-imported. */

/* Next, repeatedly delete modules with a reference count of

one (skipping builtins and sys) and delete them */

do {

ndone = 0;

pos = 0;

while (PyDict_Next(modules, &pos, &key, &value)) {

if (value->ob_refcnt != 1)

continue;

if (PyUnicode_Check(key) && PyModule_Check(value)) {

if (is_essential_module(key))

continue;

if (Py_VerboseFlag)

PySys_FormatStderr(

"# cleanup[1] %U\n", key);

_PyModule_Clear(value);

PyDict_SetItem(modules, key, Py_None);

ndone++;

}

}

} while (ndone > 0);

/* Next, delete all modules (still skipping builtins and sys) */

pos = 0;

while (PyDict_Next(modules, &pos, &key, &value)) {

if (PyUnicode_Check(key) && PyModule_Check(value)) {

if (is_essential_module(key))

continue;

if (Py_VerboseFlag)

PySys_FormatStderr("# cleanup[2] %U\n", key);

_PyModule_Clear(value);

PyDict_SetItem(modules, key, Py_None);

}

}

/* Collect garbage remaining after deleting the modules. Mostly

reference cycles created by classes. */

PyGC_Collect();

/* Dump GC stats before it's too late, since it uses the warnings

machinery. */

_PyGC_DumpShutdownStats();

/* Next, delete all remaining modules */

pos = 0;

while (PyDict_Next(modules, &pos, &key, &value)) {

if (PyUnicode_Check(key) && PyModule_Check(value)) {

if (Py_VerboseFlag)

PySys_FormatStderr("# cleanup[3] %U\n", key);

_PyModule_Clear(value);

PyDict_SetItem(modules, key, Py_None);

}

}

/* Finally, clear and delete the modules directory */

PyDict_Clear(modules);

_PyGC_CollectNoFail();

interp->modules = NULL;

Py_DECREF(modules);

}

/* Helper for pythonrun.c -- return magic number and tag. */

long

PyImport_GetMagicNumber(void)

{

long res;

PyInterpreterState *interp = PyThreadState_Get()->interp;

PyObject *pyc_magic = PyObject_GetAttrString(interp->importlib,

"_RAW_MAGIC_NUMBER");

if (pyc_magic == NULL)

return -1;

res = PyLong_AsLong(pyc_magic);

Py_DECREF(pyc_magic);

return res;

}

extern const char * _PySys_ImplCacheTag;

const char *

PyImport_GetMagicTag(void)

{

return _PySys_ImplCacheTag;

}

/* Magic for extension modules (built-in as well as dynamically

loaded). To prevent initializing an extension module more than

once, we keep a static dictionary 'extensions' keyed by the tuple

(module name, module name) (for built-in modules) or by

(filename, module name) (for dynamically loaded modules), containing these

modules. A copy of the module's dictionary is stored by calling

_PyImport_FixupExtensionObject() immediately after the module initialization

function succeeds. A copy can be retrieved from there by calling

_PyImport_FindExtensionObject().

Modules which do support multiple initialization set their m_size

field to a non-negative number (indicating the size of the

module-specific state). They are still recorded in the extensions

dictionary, to avoid loading shared libraries twice.

*/

int

_PyImport_FixupExtensionObject(PyObject *mod, PyObject *name,

PyObject *filename)

{

PyObject *modules, *dict, *key;

struct PyModuleDef *def;

int res;

if (extensions == NULL) {

extensions = PyDict_New();

if (extensions == NULL)

return -1;

}

if (mod == NULL || !PyModule_Check(mod)) {

PyErr_BadInternalCall();

return -1;

}

def = PyModule_GetDef(mod);

if (!def) {

PyErr_BadInternalCall();

return -1;

}

modules = PyImport_GetModuleDict();

if (PyDict_SetItem(modules, name, mod) < 0)

return -1;

if (_PyState_AddModule(mod, def) < 0) {

PyDict_DelItem(modules, name);

return -1;

}

if (def->m_size == -1) {

if (def->m_base.m_copy) {

/* Somebody already imported the module,

likely under a different name.

XXX this should really not happen. */

Py_DECREF(def->m_base.m_copy);

def->m_base.m_copy = NULL;

}

dict = PyModule_GetDict(mod);

if (dict == NULL)

return -1;

def->m_base.m_copy = PyDict_Copy(dict);

if (def->m_base.m_copy == NULL)

return -1;

}

key = PyTuple_Pack(2, filename, name);

if (key == NULL)

return -1;

res = PyDict_SetItem(extensions, key, (PyObject *)def);

Py_DECREF(key);

if (res < 0)

return -1;

return 0;

}

int

_PyImport_FixupBuiltin(PyObject *mod, char *name)

{

int res;

PyObject *nameobj;

nameobj = PyUnicode_InternFromString(name);

if (nameobj == NULL)

return -1;

res = _PyImport_FixupExtensionObject(mod, nameobj, nameobj);

Py_DECREF(nameobj);

return res;

}

PyObject *

_PyImport_FindExtensionObject(PyObject *name, PyObject *filename)

{

PyObject *mod, *mdict, *key;

PyModuleDef* def;

if (extensions == NULL)

return NULL;

key = PyTuple_Pack(2, filename, name);

if (key == NULL)

return NULL;

def = (PyModuleDef *)PyDict_GetItem(extensions, key);

Py_DECREF(key);

if (def == NULL)

return NULL;

if (def->m_size == -1) {

/* Module does not support repeated initialization */

if (def->m_base.m_copy == NULL)

return NULL;

mod = PyImport_AddModuleObject(name);

if (mod == NULL)

return NULL;

mdict = PyModule_GetDict(mod);

if (mdict == NULL)

return NULL;

if (PyDict_Update(mdict, def->m_base.m_copy))

return NULL;

}

else {

if (def->m_base.m_init == NULL)

return NULL;

mod = def->m_base.m_init();

if (mod == NULL)

return NULL;

PyDict_SetItem(PyImport_GetModuleDict(), name, mod);

Py_DECREF(mod);

}

if (_PyState_AddModule(mod, def) < 0) {

PyDict_DelItem(PyImport_GetModuleDict(), name);

Py_DECREF(mod);

return NULL;

}

if (Py_VerboseFlag)

PySys_FormatStderr("import %U # previously loaded (%R)\n",

name, filename);

return mod;

}

PyObject *

_PyImport_FindBuiltin(const char *name)

{

PyObject *res, *nameobj;

nameobj = PyUnicode_InternFromString(name);

if (nameobj == NULL)

return NULL;

res = _PyImport_FindExtensionObject(nameobj, nameobj);

Py_DECREF(nameobj);

return res;

}

/* Get the module object corresponding to a module name.

First check the modules dictionary if there's one there,

if not, create a new one and insert it in the modules dictionary.

Because the former action is most common, THIS DOES NOT RETURN A

'NEW' REFERENCE! */

PyObject *

PyImport_AddModuleObject(PyObject *name)

{

PyObject *modules = PyImport_GetModuleDict();

PyObject *m;

if ((m = PyDict_GetItem(modules, name)) != NULL &&

PyModule_Check(m))

return m;

m = PyModule_NewObject(name);

if (m == NULL)

return NULL;

if (PyDict_SetItem(modules, name, m) != 0) {

Py_DECREF(m);

return NULL;

}

Py_DECREF(m); /* Yes, it still exists, in modules! */

return m;

}

PyObject *

PyImport_AddModule(const char *name)

{

PyObject *nameobj, *module;

nameobj = PyUnicode_FromString(name);

if (nameobj == NULL)

return NULL;

module = PyImport_AddModuleObject(nameobj);

Py_DECREF(nameobj);

return module;

}

/* Remove name from sys.modules, if it's there. */

static void

remove_module(PyObject *name)

{

PyObject *modules = PyImport_GetModuleDict();

if (PyDict_GetItem(modules, name) == NULL)

return;

if (PyDict_DelItem(modules, name) < 0)

Py_FatalError("import: deleting existing key in"

"sys.modules failed");

}

/* Execute a code object in a module and return the module object

* WITH INCREMENTED REFERENCE COUNT. If an error occurs, name is

* removed from sys.modules, to avoid leaving damaged module objects

* in sys.modules. The caller may wish to restore the original

* module object (if any) in this case; PyImport_ReloadModule is an

* example.

*

* Note that PyImport_ExecCodeModuleWithPathnames() is the preferred, richer

* interface. The other two exist primarily for backward compatibility.

*/

PyObject *

PyImport_ExecCodeModule(char *name, PyObject *co)

{

return PyImport_ExecCodeModuleWithPathnames(

name, co, (char *)NULL, (char *)NULL);

}

PyObject *

PyImport_ExecCodeModuleEx(char *name, PyObject *co, char *pathname)

{

return PyImport_ExecCodeModuleWithPathnames(

name, co, pathname, (char *)NULL);

}

PyObject *

PyImport_ExecCodeModuleWithPathnames(char *name, PyObject *co, char *pathname,

char *cpathname)

{

PyObject *m = NULL;

PyObject *nameobj, *pathobj = NULL, *cpathobj = NULL;

nameobj = PyUnicode_FromString(name);

if (nameobj == NULL)

return NULL;

if (cpathname != NULL) {

cpathobj = PyUnicode_DecodeFSDefault(cpathname);

if (cpathobj == NULL)

goto error;

}

else

cpathobj = NULL;

if (pathname != NULL) {

pathobj = PyUnicode_DecodeFSDefault(pathname);

if (pathobj == NULL)

goto error;

}

else if (cpathobj != NULL) {

PyInterpreterState *interp = PyThreadState_GET()->interp;

_Py_IDENTIFIER(_get_sourcefile);

if (interp == NULL) {

Py_FatalError("PyImport_ExecCodeModuleWithPathnames: "

"no interpreter!");

}

pathobj = _PyObject_CallMethodIdObjArgs(interp->importlib,

&PyId__get_sourcefile, cpathobj,

NULL);

if (pathobj == NULL)

PyErr_Clear();

}

else

pathobj = NULL;

m = PyImport_ExecCodeModuleObject(nameobj, co, pathobj, cpathobj);

error:

Py_DECREF(nameobj);

Py_XDECREF(pathobj);

Py_XDECREF(cpathobj);

return m;

}

PyObject*

PyImport_ExecCodeModuleObject(PyObject *name, PyObject *co, PyObject *pathname,

PyObject *cpathname)

{

PyObject *modules = PyImport_GetModuleDict();

PyObject *m, *d, *v;

m = PyImport_AddModuleObject(name);

if (m == NULL)

return NULL;

/* If the module is being reloaded, we get the old module back

and re-use its dict to exec the new code. */

d = PyModule_GetDict(m);

if (PyDict_GetItemString(d, "__builtins__") == NULL) {

if (PyDict_SetItemString(d, "__builtins__",

PyEval_GetBuiltins()) != 0)

goto error;

}

if (pathname != NULL) {

v = pathname;

}

else {

v = ((PyCodeObject *)co)->co_filename;

}

Py_INCREF(v);

if (PyDict_SetItemString(d, "__file__", v) != 0)

PyErr_Clear(); /* Not important enough to report */

Py_DECREF(v);

/* Remember the pyc path name as the __cached__ attribute. */

if (cpathname != NULL)

v = cpathname;

else

v = Py_None;

if (PyDict_SetItemString(d, "__cached__", v) != 0)

PyErr_Clear(); /* Not important enough to report */

v = PyEval_EvalCode(co, d, d);

if (v == NULL)

goto error;

Py_DECREF(v);

if ((m = PyDict_GetItem(modules, name)) == NULL) {

PyErr_Format(PyExc_ImportError,

"Loaded module %R not found in sys.modules",

name);

return NULL;

}

Py_INCREF(m);

return m;

error:

remove_module(name);

return NULL;

}

static void

update_code_filenames(PyCodeObject *co, PyObject *oldname, PyObject *newname)

{

PyObject *constants, *tmp;

Py_ssize_t i, n;

if (PyUnicode_Compare(co->co_filename, oldname))

return;

tmp = co->co_filename;

co->co_filename = newname;

Py_INCREF(co->co_filename);

Py_DECREF(tmp);

constants = co->co_consts;

n = PyTuple_GET_SIZE(constants);

for (i = 0; i < n; i++) {

tmp = PyTuple_GET_ITEM(constants, i);

if (PyCode_Check(tmp))

update_code_filenames((PyCodeObject *)tmp,

oldname, newname);

}

}

static void

update_compiled_module(PyCodeObject *co, PyObject *newname)

{

PyObject *oldname;

if (PyUnicode_Compare(co->co_filename, newname) == 0)

return;

oldname = co->co_filename;

Py_INCREF(oldname);

update_code_filenames(co, oldname, newname);

Py_DECREF(oldname);

}

static PyObject *

imp_fix_co_filename(PyObject *self, PyObject *args)

{

PyObject *co;

PyObject *file_path;

if (!PyArg_ParseTuple(args, "OO:_fix_co_filename", &co, &file_path))

return NULL;

if (!PyCode_Check(co)) {

PyErr_SetString(PyExc_TypeError,

"first argument must be a code object");

return NULL;

}

if (!PyUnicode_Check(file_path)) {

PyErr_SetString(PyExc_TypeError,

"second argument must be a string");

return NULL;

}

update_compiled_module((PyCodeObject*)co, file_path);

Py_RETURN_NONE;

}

/* Forward */

static const struct _frozen * find_frozen(PyObject *);

/* Helper to test for built-in module */

static int

is_builtin(PyObject *name)

{

int i, cmp;

for (i = 0; PyImport_Inittab[i].name != NULL; i++) {

cmp = PyUnicode_CompareWithASCIIString(name, PyImport_Inittab[i].name);

if (cmp == 0) {

if (PyImport_Inittab[i].initfunc == NULL)

return -1;

else

return 1;

}

}

return 0;

}

/* Return an importer object for a sys.path/pkg.__path__ item 'p',

possibly by fetching it from the path_importer_cache dict. If it

wasn't yet cached, traverse path_hooks until a hook is found

that can handle the path item. Return None if no hook could;

this tells our caller it should fall back to the builtin

import mechanism. Cache the result in path_importer_cache.

Returns a borrowed reference. */

static PyObject *

get_path_importer(PyObject *path_importer_cache, PyObject *path_hooks,

PyObject *p)

{

PyObject *importer;

Py_ssize_t j, nhooks;

/* These conditions are the caller's responsibility: */

assert(PyList_Check(path_hooks));

assert(PyDict_Check(path_importer_cache));

nhooks = PyList_Size(path_hooks);

if (nhooks < 0)

return NULL; /* Shouldn't happen */

importer = PyDict_GetItem(path_importer_cache, p);

if (importer != NULL)

return importer;

/* set path_importer_cache[p] to None to avoid recursion */

if (PyDict_SetItem(path_importer_cache, p, Py_None) != 0)

return NULL;

for (j = 0; j < nhooks; j++) {

PyObject *hook = PyList_GetItem(path_hooks, j);

if (hook == NULL)

return NULL;

importer = PyObject_CallFunctionObjArgs(hook, p, NULL);

if (importer != NULL)

break;

if (!PyErr_ExceptionMatches(PyExc_ImportError)) {

return NULL;

}

PyErr_Clear();

}

if (importer == NULL) {

return Py_None;

}

if (importer != NULL) {

int err = PyDict_SetItem(path_importer_cache, p, importer);

Py_DECREF(importer);

if (err != 0)

return NULL;

}

return importer;

}

PyAPI_FUNC(PyObject *)

PyImport_GetImporter(PyObject *path) {

PyObject *importer=NULL, *path_importer_cache=NULL, *path_hooks=NULL;

if ((path_importer_cache = PySys_GetObject("path_importer_cache"))) {

if ((path_hooks = PySys_GetObject("path_hooks"))) {

importer = get_path_importer(path_importer_cache,

path_hooks, path);

}

}

Py_XINCREF(importer); /* get_path_importer returns a borrowed reference */

return importer;

}

static int init_builtin(PyObject *); /* Forward */

/* Initialize a built-in module.

Return 1 for success, 0 if the module is not found, and -1 with

an exception set if the initialization failed. */

static int

init_builtin(PyObject *name)

{

struct _inittab *p;

if (_PyImport_FindExtensionObject(name, name) != NULL)

return 1;

for (p = PyImport_Inittab; p->name != NULL; p++) {

PyObject *mod;

PyModuleDef *def;

if (PyUnicode_CompareWithASCIIString(name, p->name) == 0) {

if (p->initfunc == NULL) {

PyErr_Format(PyExc_ImportError,

"Cannot re-init internal module %R",

name);

return -1;

}

mod = (*p->initfunc)();

if (mod == 0)

return -1;

/* Remember pointer to module init function. */

def = PyModule_GetDef(mod);

def->m_base.m_init = p->initfunc;

if (_PyImport_FixupExtensionObject(mod, name, name) < 0)

return -1;

/* FixupExtension has put the module into sys.modules,

so we can release our own reference. */

Py_DECREF(mod);