[Python-checkins] cpython: Issue #3080: _PyWin_FindRegisteredModule() returns the path as Unicode

Sun Mar 20 04:13:34 CET 2011

http://hg.python.org/cpython/rev/bab42673674a
changeset: 68715:bab42673674a
user: Victor Stinner <victor.stinner at haypocalc.com>
date: Tue Mar 08 23:49:04 2011 +0100
summary:
 Issue #3080: _PyWin_FindRegisteredModule() returns the path as Unicode
 * Document the function
 * Use RegQueryValueW() instead of RegQueryValueA()
 * Use _Py_fopen() instead of fopen()
 * Allocate registry key on the heap, not on the stack, and handle memory
 allocation failure
 * Handle Python exception in find_module()
files:
 PC/import_nt.c
 Python/import.c

diff --git a/PC/import_nt.c b/PC/import_nt.c
--- a/PC/import_nt.c
+++ b/PC/import_nt.c
@@ -15,72 +15,93 @@
 /* a string loaded from the DLL at startup */
 extern const char *PyWin_DLLVersionString;
 
-FILE *_PyWin_FindRegisteredModule(const char *moduleName,
- struct filedescr **ppFileDesc,
- char *pathBuf,
- Py_ssize_t pathLen)
+/* 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)
 {
- char *moduleKey;
- const char keyPrefix[] = "Software\\Python\\PythonCore\\";
- const char keySuffix[] = "\\Modules\\";
-#ifdef _DEBUG
- /* In debugging builds, we _must_ have the debug version
- * registered.
- */
- const char debugString[] = "\\Debug";
-#else
- const char debugString[] = "";
-#endif
- struct filedescr *fdp = NULL;
- FILE *fp;
- HKEY keyBase = HKEY_CURRENT_USER;
+ 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;
 
- /* Calculate the size for the sprintf buffer.
- * Get the size of the chars only, plus 1 NULL.
- */
- size_t bufSize = sizeof(keyPrefix)-1 +
- strlen(PyWin_DLLVersionString) +
- sizeof(keySuffix) +
- strlen(moduleName) +
- sizeof(debugString) - 1;
- /* alloca == no free required, but memory only local to fn,
- * also no heap fragmentation!
- */
- moduleKey = alloca(bufSize);
- PyOS_snprintf(moduleKey, bufSize,
- "Software\\Python\\PythonCore\\%s\\Modules\\%s%s",
- PyWin_DLLVersionString, moduleName, debugString);
+ 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;
 
- assert(pathLen < INT_MAX);
- modNameSize = (int)pathLen;
- regStat = RegQueryValue(keyBase, moduleKey, pathBuf, &modNameSize);
+ 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 = (int)pathLen;
- regStat = RegQueryValue(keyBase, moduleKey,
- pathBuf, &modNameSize);
-
- if (regStat != ERROR_SUCCESS)
+ 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++) {
- size_t extLen = strlen(fdp->suffix);
- assert(modNameSize >= 0); /* else cast to size_t is wrong */
- if ((size_t)modNameSize > extLen &&
- strnicmp(pathBuf + ((size_t)modNameSize-extLen-1),
- fdp->suffix,
- extLen) == 0)
+ 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;
- fp = fopen(pathBuf, fdp->mode);
- if (fp != NULL)
- *ppFileDesc = fdp;
+ 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;
 }
diff --git a/Python/import.c b/Python/import.c
--- a/Python/import.c
+++ b/Python/import.c
@@ -1591,8 +1591,8 @@
 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 *, Py_ssize_t);
+extern FILE *_PyWin_FindRegisteredModule(PyObject *, struct filedescr **,
+ PyObject **p_path);
 #endif
 
 static int case_ok(char *, Py_ssize_t, Py_ssize_t, char *);
@@ -1679,6 +1679,9 @@
 }
 
 if (path == NULL) {
+#ifdef MS_COREDLL
+ PyObject *filename, *filename_bytes;
+#endif
 nameobj = PyUnicode_FromString(name);
 if (nameobj == NULL)
 return NULL;
@@ -1687,14 +1690,24 @@
 strcpy(buf, name);
 return &fd_builtin;
 }
- Py_DECREF(nameobj);
 #ifdef MS_COREDLL
- fp = _PyWin_FindRegisteredModule(name, &fdp, buf, buflen);
+ fp = _PyWin_FindRegisteredModule(nameobj, &fdp, &filename);
 if (fp != NULL) {
+ Py_DECREF(nameobj);
+ filename_bytes = PyUnicode_EncodeFSDefault(filename);
+ Py_DECREF(filename);
+ if (filename_bytes == NULL)
+ return NULL;
+ strncpy(buf, PyBytes_AS_STRING(filename_bytes), buflen);
+ buf[buflen-1] = '0円';
+ Py_DECREF(filename_bytes);
 *p_fp = fp;
 return fdp;
 }
+ else if (PyErr_Occurred())
+ return NULL;
 #endif
+ Py_DECREF(nameobj);
 path = PySys_GetObject("path");
 }
 
-- 
Repository URL: http://hg.python.org/cpython
