Python/dynload_shlib.c

   1
   2 /* Support for dynamic loading of extension modules */
   3
   4 #include "Python.h"
   5 #include "importdl.h"
   6
   7 #include <sys/types.h>
   8 #include <sys/stat.h>
   9
  10 #if defined(__NetBSD__)
  11 #include <sys/param.h>
  12 #if (NetBSD < 199712)
  13 #include <nlist.h>
  14 #include <link.h>
  15 #define dlerror() "error in dynamic linking"
  16 #endif
  17 #endif /* NetBSD */
  18
  19 #ifdef HAVE_DLFCN_H
  20 #include <dlfcn.h>
  21 #else
  22 #if defined(PYOS_OS2) && defined(PYCC_GCC)
  23 #include "dlfcn.h"
  24 #endif
  25 #endif
  26
  27 #if (defined(__OpenBSD__) || defined(__NetBSD__)) && !defined(__ELF__)
  28 #define LEAD_UNDERSCORE "_"
  29 #else
  30 #define LEAD_UNDERSCORE ""
  31 #endif
  32
  33
  34 const struct filedescr _PyImport_DynLoadFiletab[] = {
  35 #ifdef __CYGWIN__
  36         {".dll", "rb", C_EXTENSION},
  37         {"module.dll", "rb", C_EXTENSION},
  38 #else
  39 #if defined(PYOS_OS2) && defined(PYCC_GCC)
  40         {".pyd", "rb", C_EXTENSION},
  41         {".dll", "rb", C_EXTENSION},
  42 #else
  43 #ifdef __VMS
  44         {".exe", "rb", C_EXTENSION},
  45         {".EXE", "rb", C_EXTENSION},
  46         {"module.exe", "rb", C_EXTENSION},
  47         {"MODULE.EXE", "rb", C_EXTENSION},
  48 #else
  49         {".so", "rb", C_EXTENSION},
  50         {"module.so", "rb", C_EXTENSION},
  51 #endif
  52 #endif
  53 #endif
  54         {0, 0}
  55 };
  56
  57 static struct {
  58         dev_t dev;
  59 #ifdef __VMS
  60         ino_t ino[3];
  61 #else
  62         ino_t ino;
  63 #endif
  64         void *handle;
  65 } handles[128];
  66 static int nhandles = 0;
  67
  68
  69 dl_funcptr _PyImport_GetDynLoadFunc(const char *fqname, const char *shortname,
  70                                     const char *pathname, FILE *fp)
  71 {
  72         dl_funcptr p;
  73         void *handle;
  74         char funcname[258];
  75         char pathbuf[260];
  76         int dlopenflags=0;
  77
  78         if (strchr(pathname, '/') == NULL) {
  79                 /* Prefix bare filename with "./" */
  80                 PyOS_snprintf(pathbuf, sizeof(pathbuf), "./%-.255s", pathname);
  81                 pathname = pathbuf;
  82         }
  83
  84         PyOS_snprintf(funcname, sizeof(funcname),
  85                       LEAD_UNDERSCORE "PyInit_%.200s", shortname);
  86
  87         if (fp != NULL) {
  88                 int i;
  89                 struct stat statb;
  90                 fstat(fileno(fp), &statb);
  91                 for (i = 0; i < nhandles; i++) {
  92                         if (statb.st_dev == handles[i].dev &&
  93                             statb.st_ino == handles[i].ino) {
  94                                 p = (dl_funcptr) dlsym(handles[i].handle,
  95                                                        funcname);
  96                                 return p;
  97                         }
  98                 }
  99                 if (nhandles < 128) {
 100                         handles[nhandles].dev = statb.st_dev;
 101 #ifdef __VMS
 102                         handles[nhandles].ino[0] = statb.st_ino[0];
 103                         handles[nhandles].ino[1] = statb.st_ino[1];
 104                         handles[nhandles].ino[2] = statb.st_ino[2];
 105 #else
 106                         handles[nhandles].ino = statb.st_ino;
 107 #endif
 108                 }
 109         }
 110
 111 #if !(defined(PYOS_OS2) && defined(PYCC_GCC))
 112         dlopenflags = PyThreadState_GET()->interp->dlopenflags;
 113 #endif
 114
 115         if (Py_VerboseFlag)
 116                 PySys_WriteStderr("dlopen(\"%s\", %x);\n", pathname,
 117                                   dlopenflags);
 118
 119 #ifdef __VMS
 120         /* VMS currently don't allow a pathname, use a logical name instead */
 121         /* Concatenate 'python_module_' and shortname */
 122         /* so "import vms.bar" will use the logical python_module_bar */
 123         /* As C module use only one name space this is probably not a */
 124         /* important limitation */
 125         PyOS_snprintf(pathbuf, sizeof(pathbuf), "python_module_%-.200s",
 126                       shortname);
 127         pathname = pathbuf;
 128 #endif
 129
 130         handle = dlopen(pathname, dlopenflags);
 131
 132         if (handle == NULL) {
 133                 const char *error = dlerror();
 134                 if (error == NULL)
 135                         error = "unknown dlopen() error";
 136                 PyErr_SetString(PyExc_ImportError, error);
 137                 return NULL;
 138         }
 139         if (fp != NULL && nhandles < 128)
 140                 handles[nhandles++].handle = handle;
 141         p = (dl_funcptr) dlsym(handle, funcname);
 142         return p;
 143 }