1 /********************************************************************
2
3 import_nt.c
4
5 Win32 specific import code.
6
7 */
8
9 #include "Python.h"
10 #include "osdefs.h"
11 #include <windows.h>
12 #include "importdl.h"
13 #include "malloc.h" /* for alloca */
14
15 /* a string loaded from the DLL at startup */
16 extern const char *PyWin_DLLVersionString;
17
PyWin_FindRegisteredModule(const char * moduleName,struct filedescr ** ppFileDesc,char * pathBuf,Py_ssize_t pathLen)18 FILE *PyWin_FindRegisteredModule(const char *moduleName,
19 struct filedescr **ppFileDesc,
20 char *pathBuf,
21 Py_ssize_t pathLen)
22 {
23 char *moduleKey;
24 const char keyPrefix[] = "Software\\Python\\PythonCore\\";
25 const char keySuffix[] = "\\Modules\\";
26 #ifdef _DEBUG
27 /* In debugging builds, we _must_ have the debug version
28 * registered.
29 */
30 const char debugString[] = "\\Debug";
31 #else
32 const char debugString[] = "";
33 #endif
34 struct filedescr *fdp = NULL;
35 FILE *fp;
36 HKEY keyBase = HKEY_CURRENT_USER;
37 int modNameSize;
38 long regStat;
39
40 /* Calculate the size for the sprintf buffer.
41 * Get the size of the chars only, plus 1 NULL.
42 */
43 size_t bufSize = sizeof(keyPrefix)-1 +
44 strlen(PyWin_DLLVersionString) +
45 sizeof(keySuffix) +
46 strlen(moduleName) +
47 sizeof(debugString) - 1;
48 /* alloca == no free required, but memory only local to fn,
49 * also no heap fragmentation!
50 */
51 moduleKey = alloca(bufSize);
52 PyOS_snprintf(moduleKey, bufSize,
53 "Software\\Python\\PythonCore\\%s\\Modules\\%s%s",
54 PyWin_DLLVersionString, moduleName, debugString);
55
56 assert(pathLen < INT_MAX);
57 modNameSize = (int)pathLen;
58 regStat = RegQueryValue(keyBase, moduleKey, pathBuf, &modNameSize);
59 if (regStat != ERROR_SUCCESS) {
60 /* No user setting - lookup in machine settings */
61 keyBase = HKEY_LOCAL_MACHINE;
62 /* be anal - failure may have reset size param */
63 modNameSize = (int)pathLen;
64 regStat = RegQueryValue(keyBase, moduleKey,
65 pathBuf, &modNameSize);
66
67 if (regStat != ERROR_SUCCESS)
68 return NULL;
69 }
70 /* use the file extension to locate the type entry. */
71 for (fdp = _PyImport_Filetab; fdp->suffix != NULL; fdp++) {
72 size_t extLen = strlen(fdp->suffix);
73 assert(modNameSize >= 0); /* else cast to size_t is wrong */
74 if ((size_t)modNameSize > extLen &&
75 strnicmp(pathBuf + ((size_t)modNameSize-extLen-1),
76 fdp->suffix,
77 extLen) == 0)
78 break;
79 }
80 if (fdp->suffix == NULL)
81 return NULL;
82 fp = fopen(pathBuf, fdp->mode);
83 if (fp != NULL)
84 *ppFileDesc = fdp;
85 return fp;
86 }
87