cpython/PC/import_nt.c

108 lines
3.3 KiB
C

/********************************************************************
import_nt.c
Win32 specific import code.
*/
#include "Python.h"
#include "osdefs.h"
#include <windows.h>
#include "importdl.h"
#include "malloc.h" /* for alloca */
/* a string loaded from the DLL at startup */
extern const char *PyWin_DLLVersionString;
/* Find a module on Windows.
Read the registry Software\Python\PythonCore\<version>\Modules\<name> (or
Software\Python\PythonCore\<version>\Modules\<name>\Debug in debug mode)
from HKEY_CURRENT_USER, or HKEY_LOCAL_MACHINE. Find the file descriptor using
the file extension. Open the file.
On success, write the file descriptor into *ppFileDesc, the module path
(Unicode object) into *pPath, and return the opened file object. If the
module cannot be found (e.g. no registry key or the file doesn't exist),
return NULL. On error, raise a Python exception and return NULL.
*/
FILE *
_PyWin_FindRegisteredModule(PyObject *moduleName,
struct filedescr **ppFileDesc,
PyObject **pPath)
{
wchar_t pathBuf[MAXPATHLEN+1];
int pathLen = MAXPATHLEN+1;
PyObject *path, *moduleKey, *suffix;
struct filedescr *fdp;
HKEY keyBase;
int modNameSize;
long regStat;
Py_ssize_t extLen;
FILE *fp;
moduleKey = PyUnicode_FromFormat(
#ifdef _DEBUG
/* In debugging builds, we _must_ have the debug version registered */
"Software\\Python\\PythonCore\\%s\\Modules\\%U\\Debug",
#else
"Software\\Python\\PythonCore\\%s\\Modules\\%U",
#endif
PyWin_DLLVersionString, moduleName);
if (moduleKey == NULL)
return NULL;
keyBase = HKEY_CURRENT_USER;
modNameSize = pathLen;
regStat = RegQueryValueW(keyBase, PyUnicode_AS_UNICODE(moduleKey),
pathBuf, &modNameSize);
if (regStat != ERROR_SUCCESS) {
/* No user setting - lookup in machine settings */
keyBase = HKEY_LOCAL_MACHINE;
/* be anal - failure may have reset size param */
modNameSize = pathLen;
regStat = RegQueryValueW(keyBase, PyUnicode_AS_UNICODE(moduleKey),
pathBuf, &modNameSize);
if (regStat != ERROR_SUCCESS) {
Py_DECREF(moduleKey);
return NULL;
}
}
Py_DECREF(moduleKey);
if (modNameSize < 3) {
/* path shorter than "a.o" or negative length (cast to
size_t is wrong) */
return NULL;
}
/* use the file extension to locate the type entry. */
for (fdp = _PyImport_Filetab; fdp->suffix != NULL; fdp++) {
suffix = PyUnicode_FromString(fdp->suffix);
if (suffix == NULL)
return NULL;
extLen = PyUnicode_GET_SIZE(suffix);
if ((Py_ssize_t)modNameSize > extLen &&
_wcsnicmp(pathBuf + ((Py_ssize_t)modNameSize-extLen-1),
PyUnicode_AS_UNICODE(suffix),
extLen) == 0)
{
Py_DECREF(suffix);
break;
}
Py_DECREF(suffix);
}
if (fdp->suffix == NULL)
return NULL;
path = PyUnicode_FromUnicode(pathBuf, wcslen(pathBuf));
if (path == NULL)
return NULL;
fp = _Py_fopen(path, fdp->mode);
if (fp == NULL) {
Py_DECREF(path);
return NULL;
}
*pPath = path;
*ppFileDesc = fdp;
return fp;
}