Python/importdl.c

/***********************************************************
Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
The Netherlands.

                        All Rights Reserved

Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
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permission.

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REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
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/* Support for dynamic loading of extension modules */
/* If no dynamic linking is supported, this file still generates some code! */

#include "Python.h"
#include "importdl.h"

/* Explanation of some of the the various #defines used by dynamic linking...

   symbol	-- defined for:

   HAVE_DYNAMIC_LOADING -- any kind of dynamic linking (from ./configure)
   USE_SHLIB	-- SunOS or IRIX 5 (SVR4?) shared libraries
   _AIX		-- AIX style dynamic linking
   __NetBSD__	-- NetBSD shared libraries
		   (assuming dlerror() was introduced between 1.2 and 1.3)
   __BEOS__ -- BeOS shared libraries - defined by the compiler
*/

/* Configure dynamic linking */

#ifdef HAVE_DYNAMIC_LOADING

extern dl_funcptr _PyImport_GetDynLoadFunc(const char *name,
					   const char *funcname,
					   const char *pathname, FILE *fp);

/* ### given NeXT, is WITH_DYLD not necessary? */

#if defined(__hp9000s300) || (defined(__NetBSD__) || defined(__FreeBSD__)) && !defined(__ELF__) || defined(__OpenBSD__) || defined(__BORLANDC__) || defined(NeXT) || defined(WITH_DYLD)
#define FUNCNAME_PATTERN "_init%.200s"
#else
#define FUNCNAME_PATTERN "init%.200s"
#endif

/* ### temporary, for setting USE_SHLIB */
#if defined(__NetBSD__) && (NetBSD < 199712)
#define USE_SHLIB
#else
#if defined(HAVE_DLOPEN) || defined(M_UNIX)
#define USE_SHLIB
#endif
#endif
#ifdef _AIX
#undef USE_SHLIB
#endif
#ifdef __BEOS__
#undef USE_SHLIB
#endif

#endif /* HAVE_DYNAMIC_LOADING */

#ifdef NO_DYNAMIC_LINK
#undef HAVE_DYNAMIC_LOADING
#endif


PyObject *
_PyImport_LoadDynamicModule(name, pathname, fp)
	char *name;
	char *pathname;
	FILE *fp;
{
#ifndef HAVE_DYNAMIC_LOADING
	PyErr_SetString(PyExc_ImportError,
			"dynamically linked modules not supported");
	return NULL;
#else
	PyObject *m, *d, *s;
	char funcname[258];
	char *lastdot, *shortname, *packagecontext;
	dl_funcptr p = NULL;

#ifdef USE_SHLIB
	char pathbuf[260];
	if (strchr(pathname, '/') == NULL) {
		/* Prefix bare filename with "./" */
		sprintf(pathbuf, "./%-.255s", pathname);
		pathname = pathbuf;
	}
#endif /* USE_SHLIB */

	if ((m = _PyImport_FindExtension(name, pathname)) != NULL) {
		Py_INCREF(m);
		return m;
	}
	lastdot = strrchr(name, '.');
	if (lastdot == NULL) {
		packagecontext = NULL;
		shortname = name;
	}
	else {
		packagecontext = name;
		shortname = lastdot+1;
	}
	sprintf(funcname, FUNCNAME_PATTERN, shortname);

	p = _PyImport_GetDynLoadFunc(name, funcname, pathname, fp);
	if (PyErr_Occurred())
		return NULL;
	if (p == NULL) {
		PyErr_Format(PyExc_ImportError,
		   "dynamic module does not define init function (%.200s)",
			     funcname);
		return NULL;
	}
	_Py_PackageContext = packagecontext;
	(*p)();
	_Py_PackageContext = NULL;
	if (PyErr_Occurred())
		return NULL;
	if (_PyImport_FixupExtension(name, pathname) == NULL)
		return NULL;

	m = PyDict_GetItemString(PyImport_GetModuleDict(), name);
	if (m == NULL) {
		PyErr_SetString(PyExc_SystemError,
				"dynamic module not initialized properly");
		return NULL;
	}
	/* Remember the filename as the __file__ attribute */
	d = PyModule_GetDict(m);
	s = PyString_FromString(pathname);
	if (s == NULL || PyDict_SetItemString(d, "__file__", s) != 0)
		PyErr_Clear(); /* Not important enough to report */
	Py_XDECREF(s);
	if (Py_VerboseFlag)
		PySys_WriteStderr(
			"import %s # dynamically loaded from %s\n",
			name, pathname);
	Py_INCREF(m);
	return m;
#endif /* HAVE_DYNAMIC_LOADING */
}