PC/import_nt.c

   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 extern const char *PyWin_DLLVersionString; // a string loaded from the DLL at startup.
  16
  17 /* Return whether this is Win32s, i.e., Win32 API on Win 3.1(1).
  18    This function is exported! */
  19
  20 BOOL PyWin_IsWin32s()
  21 {
  22         static BOOL bIsWin32s = -1; /* flag as "not yet looked" */
  23
  24         if (bIsWin32s == -1) {
  25                 OSVERSIONINFO ver;
  26                 ver.dwOSVersionInfoSize = sizeof(ver);
  27                 GetVersionEx(&ver);
  28                 bIsWin32s = ver.dwPlatformId == VER_PLATFORM_WIN32s;
  29         }
  30         return bIsWin32s;
  31 }
  32
  33 FILE *PyWin_FindRegisteredModule( const char *moduleName, struct filedescr **ppFileDesc, char *pathBuf, int pathLen)
  34 {
  35         char *moduleKey;
  36         const char keyPrefix[] = "Software\\Python\\PythonCore\\";
  37         const char keySuffix[] = "\\Modules\\";
  38 #ifdef _DEBUG
  39         // In debugging builds, we _must_ have the debug version registered.
  40         const char debugString[] = "\\Debug";
  41 #else
  42         const char debugString[] = "";
  43 #endif
  44         struct filedescr *fdp = NULL;
  45         FILE *fp;
  46         HKEY keyBase = PyWin_IsWin32s() ? HKEY_CLASSES_ROOT : HKEY_LOCAL_MACHINE;
  47         int modNameSize;
  48         long regStat;
  49
  50         // Calculate the size for the sprintf buffer.
  51         // Get the size of the chars only, plus 1 NULL.
  52         int bufSize = sizeof(keyPrefix)-1 + strlen(PyWin_DLLVersionString) + sizeof(keySuffix) + strlen(moduleName) + sizeof(debugString) - 1;
  53         // alloca == no free required, but memory only local to fn, also no heap fragmentation!
  54         moduleKey = alloca(bufSize);
  55         sprintf(moduleKey, "Software\\Python\\PythonCore\\%s\\Modules\\%s%s", PyWin_DLLVersionString, moduleName, debugString);
  56
  57         modNameSize = pathLen;
  58         regStat = RegQueryValue(keyBase, moduleKey, pathBuf, &modNameSize);
  59         if (regStat!=ERROR_SUCCESS)
  60                 return NULL;
  61         // use the file extension to locate the type entry.
  62         for (fdp = _PyImport_Filetab; fdp->suffix != NULL; fdp++) {
  63                 int extLen=strlen(fdp->suffix);
  64                 if (modNameSize>extLen && strnicmp(pathBuf+(modNameSize-extLen-1),fdp->suffix,extLen)==0)
  65                         break;
  66         }
  67         if (fdp->suffix==NULL)
  68                 return NULL;
  69         fp = fopen(pathBuf, fdp->mode);
  70         if (fp != NULL)
  71                 *ppFileDesc = fdp;
  72         return fp;
  73 }
  74