/* Module definition and import implementation */

#include "Python.h"

#include "node.h"

#include "token.h"

#include "errcode.h"

#include "marshal.h"

#include "compile.h"

#include "eval.h"

#include "osdefs.h"

#include "importdl.h"

#ifdef macintosh

#include "macglue.h"

#endif

#ifdef HAVE_UNISTD_H

#include <unistd.h>

#endif

#ifdef HAVE_FCNTL_H

#include <fcntl.h>

#endif

extern time_t PyOS_GetLastModificationTime(char *, FILE *);

/* In getmtime.c */

/* Magic word to reject .pyc files generated by other Python versions */

/* Change for each incompatible change */

/* The value of CR and LF is incorporated so if you ever read or write

a .pyc file in text mode the magic number will be wrong; also, the

Apple MPW compiler swaps their values, botching string constants */

/* XXX Perhaps the magic number should be frozen and a version field

added to the .pyc file header? */

/* New way to come up with the magic number: (YEAR-1995), MONTH, DAY */

#define MAGIC (60717 | ((long)'\r'<<16) | ((long)'\n'<<24))

/* Magic word as global; note that _PyImport_Init() can change the

value of this global to accommodate for alterations of how the

compiler works which are enabled by command line switches. */

static long pyc_magic = MAGIC;

/* See _PyImport_FixupExtension() below */

static PyObject *extensions = NULL;

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

extern struct _inittab _PyImport_Inittab[];

struct _inittab *PyImport_Inittab = _PyImport_Inittab;

/* these tables define the module suffixes that Python recognizes */

struct filedescr * _PyImport_Filetab = NULL;

#ifdef RISCOS

static const struct filedescr _PyImport_StandardFiletab[] = {

{"/py", "r", PY_SOURCE},

{"/pyc", "rb", PY_COMPILED},

{0, 0}

};

#else

static const struct filedescr _PyImport_StandardFiletab[] = {

{".py", "r", PY_SOURCE},

#ifdef MS_WIN32

{".pyw", "r", PY_SOURCE},

#endif

{".pyc", "rb", PY_COMPILED},

{0, 0}

};

#endif

/* Initialize things */

void

_PyImport_Init(void)

{

const struct filedescr *scan;

struct filedescr *filetab;

int countD = 0;

int countS = 0;

/* prepare _PyImport_Filetab: copy entries from

_PyImport_DynLoadFiletab and _PyImport_StandardFiletab.

*/

for (scan = _PyImport_DynLoadFiletab; scan->suffix != NULL; ++scan)

++countD;

for (scan = _PyImport_StandardFiletab; scan->suffix != NULL; ++scan)

++countS;

filetab = PyMem_NEW(struct filedescr, countD + countS + 1);

memcpy(filetab, _PyImport_DynLoadFiletab,

countD * sizeof(struct filedescr));

memcpy(filetab + countD, _PyImport_StandardFiletab,

countS * sizeof(struct filedescr));

filetab[countD + countS].suffix = NULL;

_PyImport_Filetab = filetab;

if (Py_OptimizeFlag) {

/* Replace ".pyc" with ".pyo" in _PyImport_Filetab */

for (; filetab->suffix != NULL; filetab++) {

#ifndef RISCOS

if (strcmp(filetab->suffix, ".pyc") == 0)

filetab->suffix = ".pyo";

#else

if (strcmp(filetab->suffix, "/pyc") == 0)

filetab->suffix = "/pyo";

#endif

}

}

if (Py_UnicodeFlag) {

/* Fix the pyc_magic so that byte compiled code created

using the all-Unicode method doesn't interfere with

code created in normal operation mode. */

pyc_magic = MAGIC + 1;

}

}

void

_PyImport_Fini(void)

{

Py_XDECREF(extensions);

extensions = NULL;

PyMem_DEL(_PyImport_Filetab);

_PyImport_Filetab = NULL;

}

/* 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;

static void

lock_import(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_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);

}

import_lock_thread = me;

import_lock_level = 1;

}

static void

unlock_import(void)

{

long me = PyThread_get_thread_ident();

if (me == -1)

return; /* Too bad */

if (import_lock_thread != me)

Py_FatalError("unlock_import: not holding the import lock");

import_lock_level--;

if (import_lock_level == 0) {

import_lock_thread = -1;

PyThread_release_lock(import_lock);

}

}

#else

#define lock_import()

#define unlock_import()

#endif

static PyObject *

imp_lock_held(PyObject *self, PyObject *args)

{

if (!PyArg_ParseTuple(args, ":lock_held"))

return NULL;

#ifdef WITH_THREAD

return PyInt_FromLong(import_lock_thread != -1);

#else

return PyInt_FromLong(0);

#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", "exitfunc",

"exc_type", "exc_value", "exc_traceback",

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

NULL

};

static char* sys_files[] = {

"stdin", "__stdin__",

"stdout", "__stdout__",

"stderr", "__stderr__",

NULL

};

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

void

PyImport_Cleanup(void)

{

int pos, ndone;

char *name;

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, "__builtin__");

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

dict = PyModule_GetDict(value);

if (Py_VerboseFlag)

PySys_WriteStderr("# clear __builtin__._\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 __builtin__ 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 __builtin__

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 __builtin__ and sys) and delete them */

do {

ndone = 0;

pos = 0;

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

if (value->ob_refcnt != 1)

continue;

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

name = PyString_AS_STRING(key);

if (strcmp(name, "__builtin__") == 0)

continue;

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

continue;

if (Py_VerboseFlag)

PySys_WriteStderr(

"# cleanup[1] %s\n", name);

_PyModule_Clear(value);

PyDict_SetItem(modules, key, Py_None);

ndone++;

}

}

} while (ndone > 0);

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

pos = 0;

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

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

name = PyString_AS_STRING(key);

if (strcmp(name, "__builtin__") == 0)

continue;

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

continue;

if (Py_VerboseFlag)

PySys_WriteStderr("# cleanup[2] %s\n", name);

_PyModule_Clear(value);

PyDict_SetItem(modules, key, Py_None);

}

}

/* Next, delete sys and __builtin__ (in that order) */

value = PyDict_GetItemString(modules, "sys");

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

if (Py_VerboseFlag)

PySys_WriteStderr("# cleanup sys\n");

_PyModule_Clear(value);

PyDict_SetItemString(modules, "sys", Py_None);

}

value = PyDict_GetItemString(modules, "__builtin__");

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

if (Py_VerboseFlag)

PySys_WriteStderr("# cleanup __builtin__\n");

_PyModule_Clear(value);

PyDict_SetItemString(modules, "__builtin__", Py_None);

}

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

PyDict_Clear(modules);

interp->modules = NULL;

Py_DECREF(modules);

}

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

long

PyImport_GetMagicNumber(void)

{

return pyc_magic;

}

/* 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 module name

(for built-in modules) or by filename (for dynamically loaded

modules), containing these modules. A copy of the module's

dictionary is stored by calling _PyImport_FixupExtension()

immediately after the module initialization function succeeds. A

copy can be retrieved from there by calling

_PyImport_FindExtension(). */

PyObject *

_PyImport_FixupExtension(char *name, char *filename)

{

PyObject *modules, *mod, *dict, *copy;

if (extensions == NULL) {

extensions = PyDict_New();

if (extensions == NULL)

return NULL;

}

modules = PyImport_GetModuleDict();

mod = PyDict_GetItemString(modules, name);

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

PyErr_Format(PyExc_SystemError,

"_PyImport_FixupExtension: module %.200s not loaded", name);

return NULL;

}

dict = PyModule_GetDict(mod);

if (dict == NULL)

return NULL;

copy = PyObject_CallMethod(dict, "copy", "");

if (copy == NULL)

return NULL;

PyDict_SetItemString(extensions, filename, copy);

Py_DECREF(copy);

return copy;

}

PyObject *

_PyImport_FindExtension(char *name, char *filename)

{

PyObject *dict, *mod, *mdict, *result;

if (extensions == NULL)

return NULL;

dict = PyDict_GetItemString(extensions, filename);

if (dict == NULL)

return NULL;

mod = PyImport_AddModule(name);

if (mod == NULL)

return NULL;

mdict = PyModule_GetDict(mod);

if (mdict == NULL)

return NULL;

result = PyObject_CallMethod(mdict, "update", "O", dict);

if (result == NULL)

return NULL;

Py_DECREF(result);

if (Py_VerboseFlag)

PySys_WriteStderr("import %s # previously loaded (%s)\n",

name, filename);

return mod;

}

/* 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 in in the modules dictionary.

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

'NEW' REFERENCE! */

PyObject *

PyImport_AddModule(char *name)

{

PyObject *modules = PyImport_GetModuleDict();

PyObject *m;

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

PyModule_Check(m))

return m;

m = PyModule_New(name);

if (m == NULL)

return NULL;

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

Py_DECREF(m);

return NULL;

}

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

return m;

}

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

WITH INCREMENTED REFERENCE COUNT */

PyObject *

PyImport_ExecCodeModule(char *name, PyObject *co)

{

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

}

PyObject *

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

{

PyObject *modules = PyImport_GetModuleDict();

PyObject *m, *d, *v;

m = PyImport_AddModule(name);

if (m == NULL)

return NULL;

d = PyModule_GetDict(m);

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

if (PyDict_SetItemString(d, "__builtins__",

PyEval_GetBuiltins()) != 0)

return NULL;

}

/* Remember the filename as the __file__ attribute */

v = NULL;

if (pathname != NULL) {

v = PyString_FromString(pathname);

if (v == NULL)

PyErr_Clear();

}

if (v == NULL) {

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);

v = PyEval_EvalCode((PyCodeObject *)co, d, d);

if (v == NULL)

return NULL;

Py_DECREF(v);

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

PyErr_Format(PyExc_ImportError,

"Loaded module %.200s not found in sys.modules",

name);

return NULL;

}

Py_INCREF(m);

return m;

}

/* Given a pathname for a Python source file, fill a buffer with the

pathname for the corresponding compiled file. Return the pathname

for the compiled file, or NULL if there's no space in the buffer.

Doesn't set an exception. */

static char *

make_compiled_pathname(char *pathname, char *buf, size_t buflen)

{

size_t len = strlen(pathname);

if (len+2 > buflen)

return NULL;

#ifdef MS_WIN32

/* Treat .pyw as if it were .py. The case of ".pyw" must match

that used in _PyImport_StandardFiletab. */

if (len >= 4 && strcmp(&pathname[len-4], ".pyw") == 0)

--len; /* pretend 'w' isn't there */

#endif

memcpy(buf, pathname, len);

buf[len] = Py_OptimizeFlag ? 'o' : 'c';

buf[len+1] = '\0';

return buf;

}

/* Given a pathname for a Python source file, its time of last

modification, and a pathname for a compiled file, check whether the

compiled file represents the same version of the source. If so,

return a FILE pointer for the compiled file, positioned just after

the header; if not, return NULL.

Doesn't set an exception. */

static FILE *

check_compiled_module(char *pathname, long mtime, char *cpathname)

{

FILE *fp;

long magic;

long pyc_mtime;

fp = fopen(cpathname, "rb");

if (fp == NULL)

return NULL;

magic = PyMarshal_ReadLongFromFile(fp);

if (magic != pyc_magic) {

if (Py_VerboseFlag)

PySys_WriteStderr("# %s has bad magic\n", cpathname);

fclose(fp);

return NULL;

}

pyc_mtime = PyMarshal_ReadLongFromFile(fp);

if (pyc_mtime != mtime) {

if (Py_VerboseFlag)

PySys_WriteStderr("# %s has bad mtime\n", cpathname);

fclose(fp);

return NULL;

}

if (Py_VerboseFlag)

PySys_WriteStderr("# %s matches %s\n", cpathname, pathname);

return fp;

}

/* Read a code object from a file and check it for validity */

static PyCodeObject *

read_compiled_module(char *cpathname, FILE *fp)

{

PyObject *co;

co = PyMarshal_ReadLastObjectFromFile(fp);

/* Ugly: rd_object() may return NULL with or without error */

if (co == NULL || !PyCode_Check(co)) {

if (!PyErr_Occurred())

PyErr_Format(PyExc_ImportError,

"Non-code object in %.200s", cpathname);

Py_XDECREF(co);

return NULL;

}

return (PyCodeObject *)co;

}

/* Load a module from a compiled file, execute it, and return its

module object WITH INCREMENTED REFERENCE COUNT */

static PyObject *

load_compiled_module(char *name, char *cpathname, FILE *fp)

{

long magic;

PyCodeObject *co;

PyObject *m;

magic = PyMarshal_ReadLongFromFile(fp);

if (magic != pyc_magic) {

PyErr_Format(PyExc_ImportError,

"Bad magic number in %.200s", cpathname);

return NULL;

}

(void) PyMarshal_ReadLongFromFile(fp);

co = read_compiled_module(cpathname, fp);

if (co == NULL)

return NULL;

if (Py_VerboseFlag)

PySys_WriteStderr("import %s # precompiled from %s\n",

name, cpathname);

m = PyImport_ExecCodeModuleEx(name, (PyObject *)co, cpathname);

Py_DECREF(co);

return m;

}

/* Parse a source file and return the corresponding code object */

static PyCodeObject *

parse_source_module(char *pathname, FILE *fp)

{

PyCodeObject *co;

node *n;

n = PyParser_SimpleParseFile(fp, pathname, Py_file_input);

if (n == NULL)

return NULL;

co = PyNode_Compile(n, pathname);

PyNode_Free(n);

return co;

}

/* Helper to open a bytecode file for writing in exclusive mode */

static FILE *

open_exclusive(char *filename)

{

#if defined(O_EXCL)&&defined(O_CREAT)&&defined(O_WRONLY)&&defined(O_TRUNC)

/* Use O_EXCL to avoid a race condition when another process tries to

write the same file. When that happens, our open() call fails,

which is just fine (since it's only a cache).

XXX If the file exists and is writable but the directory is not

writable, the file will never be written. Oh well.

*/

int fd;

(void) unlink(filename);

fd = open(filename, O_EXCL|O_CREAT|O_WRONLY|O_TRUNC

#ifdef O_BINARY

|O_BINARY /* necessary for Windows */

#endif

, 0666);

if (fd < 0)

return NULL;

return fdopen(fd, "wb");

#else

/* Best we can do -- on Windows this can't happen anyway */

return fopen(filename, "wb");

#endif

}

/* Write a compiled module to a file, placing the time of last

modification of its source into the header.

Errors are ignored, if a write error occurs an attempt is made to

remove the file. */

static void

write_compiled_module(PyCodeObject *co, char *cpathname, long mtime)

{

FILE *fp;

fp = open_exclusive(cpathname);

if (fp == NULL) {

if (Py_VerboseFlag)

PySys_WriteStderr(

"# can't create %s\n", cpathname);

return;

}

PyMarshal_WriteLongToFile(pyc_magic, fp);

/* First write a 0 for mtime */

PyMarshal_WriteLongToFile(0L, fp);

PyMarshal_WriteObjectToFile((PyObject *)co, fp);

if (ferror(fp)) {

if (Py_VerboseFlag)

PySys_WriteStderr("# can't write %s\n", cpathname);

/* Don't keep partial file */

fclose(fp);

(void) unlink(cpathname);

return;

}

/* Now write the true mtime */

fseek(fp, 4L, 0);

PyMarshal_WriteLongToFile(mtime, fp);

fflush(fp);

fclose(fp);

if (Py_VerboseFlag)

PySys_WriteStderr("# wrote %s\n", cpathname);

#ifdef macintosh

PyMac_setfiletype(cpathname, 'Pyth', 'PYC ');

#endif

}

/* Load a source module from a given file and return its module

object WITH INCREMENTED REFERENCE COUNT. If there's a matching

byte-compiled file, use that instead. */

static PyObject *

load_source_module(char *name, char *pathname, FILE *fp)

{

time_t mtime;

FILE *fpc;

char buf[MAXPATHLEN+1];

char *cpathname;

PyCodeObject *co;

PyObject *m;

mtime = PyOS_GetLastModificationTime(pathname, fp);

if (mtime == (time_t)(-1))

return NULL;

#if SIZEOF_TIME_T > 4

/* Python's .pyc timestamp handling presumes that the timestamp fits

in 4 bytes. This will be fine until sometime in the year 2038,

when a 4-byte signed time_t will overflow.

*/

if (mtime >> 32) {

PyErr_SetString(PyExc_OverflowError,

"modification time overflows a 4 byte field");

return NULL;

}

#endif

cpathname = make_compiled_pathname(pathname, buf,

(size_t)MAXPATHLEN + 1);

if (cpathname != NULL &&

(fpc = check_compiled_module(pathname, mtime, cpathname))) {

co = read_compiled_module(cpathname, fpc);

fclose(fpc);

if (co == NULL)

return NULL;

if (Py_VerboseFlag)

PySys_WriteStderr("import %s # precompiled from %s\n",

name, cpathname);

pathname = cpathname;

}

else {

co = parse_source_module(pathname, fp);

if (co == NULL)

return NULL;

if (Py_VerboseFlag)

PySys_WriteStderr("import %s # from %s\n",

name, pathname);

write_compiled_module(co, cpathname, mtime);

}

m = PyImport_ExecCodeModuleEx(name, (PyObject *)co, pathname);

Py_DECREF(co);

return m;

}

/* Forward */

static PyObject *load_module(char *, FILE *, char *, int);

static struct filedescr *find_module(char *, PyObject *,

char *, size_t, FILE **);

static struct _frozen *find_frozen(char *name);

/* Load a package and return its module object WITH INCREMENTED

REFERENCE COUNT */

static PyObject *

load_package(char *name, char *pathname)

{

PyObject *m, *d, *file, *path;

int err;

char buf[MAXPATHLEN+1];

FILE *fp = NULL;

struct filedescr *fdp;

m = PyImport_AddModule(name);

if (m == NULL)

return NULL;

if (Py_VerboseFlag)

PySys_WriteStderr("import %s # directory %s\n",

name, pathname);

d = PyModule_GetDict(m);

file = PyString_FromString(pathname);

if (file == NULL)

return NULL;

path = Py_BuildValue("[O]", file);

if (path == NULL) {

Py_DECREF(file);

return NULL;

}

err = PyDict_SetItemString(d, "__file__", file);

if (err == 0)

err = PyDict_SetItemString(d, "__path__", path);

if (err != 0) {

m = NULL;

goto cleanup;

}

buf[0] = '\0';

fdp = find_module("__init__", path, buf, sizeof(buf), &fp);

if (fdp == NULL) {

if (PyErr_ExceptionMatches(PyExc_ImportError)) {

PyErr_Clear();

}

else

m = NULL;

goto cleanup;

}

m = load_module(name, fp, buf, fdp->type);

if (fp != NULL)

fclose(fp);

cleanup:

Py_XDECREF(path);

Py_XDECREF(file);

return m;

}

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

static int

is_builtin(char *name)

{

int i;

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

if (strcmp(name, PyImport_Inittab[i].name) == 0) {

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

return -1;

else

return 1;

}

}

return 0;

}

/* Search the path (default sys.path) for a module. Return the

corresponding filedescr struct, and (via return arguments) the

pathname and an open file. Return NULL if the module is not found. */

#ifdef MS_COREDLL

extern FILE *PyWin_FindRegisteredModule(const char *, struct filedescr **,

char *, int);

#endif

static int case_ok(char *, int, int, char *);

static int find_init_module(char *); /* Forward */

static struct filedescr *

find_module(char *realname, PyObject *path, char *buf, size_t buflen,

FILE **p_fp)

{

int i, npath;

size_t len, namelen;

struct filedescr *fdp = NULL;

FILE *fp = NULL;

#ifndef RISCOS

struct stat statbuf;

#endif

static struct filedescr fd_frozen = {"", "", PY_FROZEN};

static struct filedescr fd_builtin = {"", "", C_BUILTIN};

static struct filedescr fd_package = {"", "", PKG_DIRECTORY};

char name[MAXPATHLEN+1];

if (strlen(realname) > MAXPATHLEN) {

PyErr_SetString(PyExc_OverflowError, "module name is too long");

return NULL;

}

strcpy(name, realname);

if (path != NULL && PyString_Check(path)) {

/* Submodule of "frozen" package:

Set name to the fullname, path to NULL

and continue as "usual" */

if (PyString_Size(path) + 1 + strlen(name) >= (size_t)buflen) {

PyErr_SetString(PyExc_ImportError,

"full frozen module name too long");

return NULL;

}

strcpy(buf, PyString_AsString(path));

strcat(buf, ".");

strcat(buf, name);

strcpy(name, buf);

path = NULL;

}

if (path == NULL) {

if (is_builtin(name)) {

strcpy(buf, name);

return &fd_builtin;

}

if ((find_frozen(name)) != NULL) {

strcpy(buf, name);

return &fd_frozen;

}

#ifdef MS_COREDLL

fp = PyWin_FindRegisteredModule(name, &fdp, buf, buflen);

if (fp != NULL) {

*p_fp = fp;

return fdp;

}

#endif

path = PySys_GetObject("path");

}

if (path == NULL || !PyList_Check(path)) {

PyErr_SetString(PyExc_ImportError,

"sys.path must be a list of directory names");

return NULL;

}

npath = PyList_Size(path);

namelen = strlen(name);

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

PyObject *v = PyList_GetItem(path, i);

if (!PyString_Check(v))

continue;

len = PyString_Size(v);

if (len + 2 + namelen + MAXSUFFIXSIZE >= buflen)

continue; /* Too long */

strcpy(buf, PyString_AsString(v));

if (strlen(buf) != len)

continue; /* v contains '\0' */

#ifdef macintosh

#ifdef INTERN_STRINGS

/*

** Speedup: each sys.path item is interned, and

** FindResourceModule remembers which items refer to

** folders (so we don't have to bother trying to look

** into them for resources).

*/

PyString_InternInPlace(&PyList_GET_ITEM(path, i));

v = PyList_GET_ITEM(path, i);

#endif

if (PyMac_FindResourceModule((PyStringObject *)v, name, buf)) {

static struct filedescr resfiledescr =

{"", "", PY_RESOURCE};

return &resfiledescr;

}

if (PyMac_FindCodeResourceModule((PyStringObject *)v, name, buf)) {

static struct filedescr resfiledescr =

{"", "", PY_CODERESOURCE};

return &resfiledescr;

}

#endif

if (len > 0 && buf[len-1] != SEP

#ifdef ALTSEP

&& buf[len-1] != ALTSEP

#endif

)

buf[len++] = SEP;

strcpy(buf+len, name);

len += namelen;

/* Check for package import (buf holds a directory name,

and there's an __init__ module in that directory */

#ifdef HAVE_STAT

if (stat(buf, &statbuf) == 0 && /* it exists */

S_ISDIR(statbuf.st_mode) && /* it's a directory */

find_init_module(buf) && /* it has __init__.py */

case_ok(buf, len, namelen, name)) /* and case matches */

return &fd_package;

#else

/* XXX How are you going to test for directories? */

#ifdef RISCOS

{

static struct filedescr fd = {"", "", PKG_DIRECTORY};

if (isdir(buf)) {

if (find_init_module(buf))

return &fd;

}

}

#endif

#endif

#ifdef macintosh

fdp = PyMac_FindModuleExtension(buf, &len, name);

if (fdp) {

#else

for (fdp = _PyImport_Filetab; fdp->suffix != NULL; fdp++) {

strcpy(buf+len, fdp->suffix);

if (Py_VerboseFlag > 1)

PySys_WriteStderr("# trying %s\n", buf);

#endif /* !macintosh */

fp = fopen(buf, fdp->mode);

if (fp != NULL) {

if (case_ok(buf, len, namelen, name))