AppPkg/Applications/Python/Python-2.7.2/Python/dynload_next.c

   1
   2 /* Support for dynamic loading of extension modules on Mac OS X
   3 ** All references to "NeXT" are for historical reasons.
   4 */
   5
   6 #include "Python.h"
   7 #include "importdl.h"
   8
   9 #include <mach-o/dyld.h>
  10
  11 const struct filedescr _PyImport_DynLoadFiletab[] = {
  12     {".so", "rb", C_EXTENSION},
  13     {"module.so", "rb", C_EXTENSION},
  14     {0, 0}
  15 };
  16
  17 /*
  18 ** Python modules are Mach-O MH_BUNDLE files. The best way to load these
  19 ** is each in a private namespace, so you can load, say, a module bar and a
  20 ** module foo.bar. If we load everything in the global namespace the two
  21 ** initbar() symbols will conflict.
  22 ** However, it seems some extension packages depend upon being able to access
  23 ** each others' global symbols. There seems to be no way to eat our cake and
  24 ** have it, so the USE_DYLD_GLOBAL_NAMESPACE define determines which behaviour
  25 ** you get.
  26 */
  27
  28 #ifdef USE_DYLD_GLOBAL_NAMESPACE
  29 #define LINKOPTIONS NSLINKMODULE_OPTION_BINDNOW|NSLINKMODULE_OPTION_RETURN_ON_ERROR
  30 #else
  31 #define LINKOPTIONS NSLINKMODULE_OPTION_BINDNOW| \
  32     NSLINKMODULE_OPTION_RETURN_ON_ERROR|NSLINKMODULE_OPTION_PRIVATE
  33 #endif
  34 dl_funcptr _PyImport_GetDynLoadFunc(const char *fqname, const char *shortname,
  35                                         const char *pathname, FILE *fp)
  36 {
  37     dl_funcptr p = NULL;
  38     char funcname[258];
  39     NSObjectFileImageReturnCode rc;
  40     NSObjectFileImage image;
  41     NSModule newModule;
  42     NSSymbol theSym;
  43     const char *errString;
  44     char errBuf[512];
  45
  46     PyOS_snprintf(funcname, sizeof(funcname), "_init%.200s", shortname);
  47
  48 #ifdef USE_DYLD_GLOBAL_NAMESPACE
  49     if (NSIsSymbolNameDefined(funcname)) {
  50         theSym = NSLookupAndBindSymbol(funcname);
  51         p = (dl_funcptr)NSAddressOfSymbol(theSym);
  52         return p;
  53     }
  54 #endif
  55     rc = NSCreateObjectFileImageFromFile(pathname, &image);
  56     switch(rc) {
  57         default:
  58         case NSObjectFileImageFailure:
  59         case NSObjectFileImageFormat:
  60             /* for these a message is printed on stderr by dyld */
  61             errString = "Can't create object file image";
  62         break;
  63         case NSObjectFileImageSuccess:
  64             errString = NULL;
  65             break;
  66         case NSObjectFileImageInappropriateFile:
  67             errString = "Inappropriate file type for dynamic loading";
  68             break;
  69         case NSObjectFileImageArch:
  70             errString = "Wrong CPU type in object file";
  71             break;
  72         case NSObjectFileImageAccess:
  73             errString = "Can't read object file (no access)";
  74             break;
  75     }
  76     if (errString == NULL) {
  77         newModule = NSLinkModule(image, pathname, LINKOPTIONS);
  78         if (newModule == NULL) {
  79             int errNo;
  80             const char *fileName, *moreErrorStr;
  81             NSLinkEditErrors c;
  82             NSLinkEditError( &c, &errNo, &fileName, &moreErrorStr );
  83             PyOS_snprintf(errBuf, 512, "Failure linking new module: %s: %s",
  84                             fileName, moreErrorStr);
  85             errString = errBuf;
  86         }
  87     }
  88     if (errString != NULL) {
  89         PyErr_SetString(PyExc_ImportError, errString);
  90         return NULL;
  91     }
  92 #ifdef USE_DYLD_GLOBAL_NAMESPACE
  93     if (!NSIsSymbolNameDefined(funcname)) {
  94         /* UnlinkModule() isn't implemented in current versions, but calling it does no harm */
  95         /* NSUnLinkModule(newModule, FALSE); removed: causes problems for ObjC code */
  96         PyErr_Format(PyExc_ImportError,
  97                          "Loaded module does not contain symbol %.200s",
  98                          funcname);
  99         return NULL;
 100     }
 101     theSym = NSLookupAndBindSymbol(funcname);
 102 #else
 103     theSym = NSLookupSymbolInModule(newModule, funcname);
 104     if ( theSym == NULL ) {
 105         /* NSUnLinkModule(newModule, FALSE); removed: causes problems for ObjC code */
 106         PyErr_Format(PyExc_ImportError,
 107                          "Loaded module does not contain symbol %.200s",
 108                          funcname);
 109         return NULL;
 110     }
 111 #endif
 112     p = (dl_funcptr)NSAddressOfSymbol(theSym);
 113     return p;
 114 }