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      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 "init%.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 }
    144