import.c

python s60 1.4.5版本的源代码

	default:
		PyErr_Format(PyExc_ImportError,
			     "Don't know how to import %.200s (type code %d)",
			      name, type);
		m = NULL;

	}

	return m;
}


/* Initialize a built-in module.
   Return 1 for succes, 0 if the module is not found, and -1 with
   an exception set if the initialization failed. */

static int
init_builtin(char *name)
{
	struct _inittab *p;

	if (_PyImport_FindExtension(name, name) != NULL)
		return 1;

	for (p = PyImport_Inittab; p->name != NULL; p++) {
		if (strcmp(name, p->name) == 0) {
			if (p->initfunc == NULL) {
				PyErr_Format(PyExc_ImportError,
				    "Cannot re-init internal module %.200s",
				    name);
				return -1;
			}
			if (Py_VerboseFlag)
				PySys_WriteStderr("import %s # builtin\n", name);
			(*p->initfunc)();
			if (PyErr_Occurred())
				return -1;
			if (_PyImport_FixupExtension(name, name) == NULL)
				return -1;
			return 1;
		}
	}
	return 0;
}


/* Frozen modules */

#ifdef SYMBIAN
#define PyImport_FrozenModules (PYTHON_GLOBALS->PyImport_FrozenModules)
#endif

static struct _frozen *
find_frozen(char *name)
{
	struct _frozen *p;

#ifdef SYMBIAN
	// XXX:CW32
	if (!PyImport_FrozenModules)
	  PyImport_FrozenModules = (struct _frozen *)_PyImport_FrozenModules;
#endif

	for (p = PyImport_FrozenModules; ; p++) {
		if (p->name == NULL)
			return NULL;
		if (strcmp(p->name, name) == 0)
			break;
	}
	return p;
}

static PyObject *
get_frozen_object(char *name)
{
	struct _frozen *p = find_frozen(name);
	int size;

	if (p == NULL) {
		PyErr_Format(PyExc_ImportError,
			     "No such frozen object named %.200s",
			     name);
		return NULL;
	}
	if (p->code == NULL) {
		PyErr_Format(PyExc_ImportError,
			     "Excluded frozen object named %.200s",
			     name);
		return NULL;
	}
	size = p->size;
	if (size < 0)
		size = -size;
	return PyMarshal_ReadObjectFromString((char *)p->code, size);
}

/* Initialize a frozen module.
   Return 1 for succes, 0 if the module is not found, and -1 with
   an exception set if the initialization failed.
   This function is also used from frozenmain.c */

DL_EXPORT(int)
PyImport_ImportFrozenModule(char *name)
{
	struct _frozen *p = find_frozen(name);
	PyObject *co;
	PyObject *m;
	int ispackage;
	int size;

	if (p == NULL)
		return 0;
	if (p->code == NULL) {
		PyErr_Format(PyExc_ImportError,
			     "Excluded frozen object named %.200s",
			     name);
		return -1;
	}
	size = p->size;
	ispackage = (size < 0);
	if (ispackage)
		size = -size;
	if (Py_VerboseFlag)
		PySys_WriteStderr("import %s # frozen%s\n",
			name, ispackage ? " package" : "");
	co = PyMarshal_ReadObjectFromString((char *)p->code, size);
	if (co == NULL)
		return -1;
	if (!PyCode_Check(co)) {
		Py_DECREF(co);
		PyErr_Format(PyExc_TypeError,
			     "frozen object %.200s is not a code object",
			     name);
		return -1;
	}
	if (ispackage) {
		/* Set __path__ to the package name */
		PyObject *d, *s;
		int err;
		m = PyImport_AddModule(name);
		if (m == NULL)
			return -1;
		d = PyModule_GetDict(m);
		s = PyString_InternFromString(name);
		if (s == NULL)
			return -1;
		err = PyDict_SetItemString(d, "__path__", s);
		Py_DECREF(s);
		if (err != 0)
			return err;
	}
	m = PyImport_ExecCodeModuleEx(name, co, "<frozen>");
	Py_DECREF(co);
	if (m == NULL)
		return -1;
	Py_DECREF(m);
	return 1;
}


/* Import a module, either built-in, frozen, or external, and return
   its module object WITH INCREMENTED REFERENCE COUNT */

DL_EXPORT(PyObject *)
PyImport_ImportModule(char *name)
{
	PyObject *pname;
	PyObject *result;

	pname = PyString_FromString(name);
	result = PyImport_Import(pname);
	Py_DECREF(pname);
	return result;
}

/* Forward declarations for helper routines */
static PyObject *get_parent(PyObject *globals, char *buf, int *p_buflen);
static PyObject *load_next(PyObject *mod, PyObject *altmod,
			   char **p_name, char *buf, int *p_buflen);
static int mark_miss(char *name);
static int ensure_fromlist(PyObject *mod, PyObject *fromlist,
			   char *buf, int buflen, int recursive);
static PyObject * import_submodule(PyObject *mod, char *name, char *fullname);

/* The Magnum Opus of dotted-name import :-) */

static PyObject *
import_module_ex(char *name, PyObject *globals, PyObject *locals,
		 PyObject *fromlist)
{
	char buf[MAXPATHLEN+1];
	int buflen = 0;
	PyObject *parent, *head, *next, *tail;

	parent = get_parent(globals, buf, &buflen);
	if (parent == NULL)
		return NULL;

	head = load_next(parent, Py_None, &name, buf, &buflen);
	if (head == NULL)
		return NULL;

	tail = head;
	Py_INCREF(tail);
	while (name) {
		next = load_next(tail, tail, &name, buf, &buflen);
		Py_DECREF(tail);
		if (next == NULL) {
			Py_DECREF(head);
			return NULL;
		}
		tail = next;
	}

	if (fromlist != NULL) {
		if (fromlist == Py_None || !PyObject_IsTrue(fromlist))
			fromlist = NULL;
	}

	if (fromlist == NULL) {
		Py_DECREF(tail);
		return head;
	}

	Py_DECREF(head);
	if (!ensure_fromlist(tail, fromlist, buf, buflen, 0)) {
		Py_DECREF(tail);
		return NULL;
	}

	return tail;
}

DL_EXPORT(PyObject *)
PyImport_ImportModuleEx(char *name, PyObject *globals, PyObject *locals,
			PyObject *fromlist)
{
	PyObject *result;
	lock_import();
	result = import_module_ex(name, globals, locals, fromlist);
	unlock_import();
	return result;
}
#ifndef SYMBIAN
static PyObject *
get_parent(PyObject *globals, char *buf, int *p_buflen)
{
	static PyObject *namestr = NULL;
	static PyObject *pathstr = NULL;
	PyObject *modname, *modpath, *modules, *parent;

	if (globals == NULL || !PyDict_Check(globals))
		return Py_None;

	if (namestr == NULL) {
		namestr = PyString_InternFromString("__name__");
		if (namestr == NULL)
			return NULL;
	}
	if (pathstr == NULL) {
		pathstr = PyString_InternFromString("__path__");
		if (pathstr == NULL)
			return NULL;
	}

	*buf = '\0';
	*p_buflen = 0;
	modname = PyDict_GetItem(globals, namestr);
	if (modname == NULL || !PyString_Check(modname))
		return Py_None;

	modpath = PyDict_GetItem(globals, pathstr);
	if (modpath != NULL) {
		int len = PyString_GET_SIZE(modname);
		if (len > MAXPATHLEN) {
			PyErr_SetString(PyExc_ValueError,
					"Module name too long");
			return NULL;
		}
		strcpy(buf, PyString_AS_STRING(modname));
		*p_buflen = len;
	}
	else {
		char *start = PyString_AS_STRING(modname);
		char *lastdot = strrchr(start, '.');
		size_t len;
		if (lastdot == NULL)
			return Py_None;
		len = lastdot - start;
		if (len >= MAXPATHLEN) {
			PyErr_SetString(PyExc_ValueError,
					"Module name too long");
			return NULL;
		}
		strncpy(buf, start, len);
		buf[len] = '\0';
		*p_buflen = len;
	}

	modules = PyImport_GetModuleDict();
	parent = PyDict_GetItemString(modules, buf);
	if (parent == NULL)
		parent = Py_None;
	return parent;
	/* We expect, but can't guarantee, if parent != None, that:
	   - parent.__name__ == buf
	   - parent.__dict__ is globals
	   If this is violated...  Who cares? */
}
#else
static PyObject *
get_parent(PyObject *globals, char *buf, int *p_buflen)
{
	PyObject *modname, *modpath, *modules, *parent;

	PyObject **pnamestr = &(PYTHON_GLOBALS->namestr);
	PyObject **ppathstr = &(PYTHON_GLOBALS->pathstr);

	if (globals == NULL || !PyDict_Check(globals))
		return Py_None;

	if (*pnamestr == NULL) {
		*pnamestr = PyString_InternFromString("__name__");
		if (*pnamestr == NULL)
			return NULL;
	}
	if (*ppathstr == NULL) {
		*ppathstr = PyString_InternFromString("__path__");
		if (*ppathstr == NULL)
			return NULL;
	}

	*buf = '\0';
	*p_buflen = 0;
	modname = PyDict_GetItem(globals, *pnamestr);
	if (modname == NULL || !PyString_Check(modname))
		return Py_None;

	modpath = PyDict_GetItem(globals, *ppathstr);
	if (modpath != NULL) {
		int len = PyString_GET_SIZE(modname);
		if (len > MAXPATHLEN) {
			PyErr_SetString(PyExc_ValueError,
					"Module name too long");
			return NULL;
		}
		strcpy(buf, PyString_AS_STRING(modname));
		*p_buflen = len;
	}
	else {
		char *start = PyString_AS_STRING(modname);
		char *lastdot = strrchr(start, '.');
		size_t len;
		if (lastdot == NULL)
			return Py_None;
		len = lastdot - start;
		if (len >= MAXPATHLEN) {
			PyErr_SetString(PyExc_ValueError,
					"Module name too long");
			return NULL;
		}
		strncpy(buf, start, len);
		buf[len] = '\0';
		*p_buflen = len;
	}

	modules = PyImport_GetModuleDict();
	parent = PyDict_GetItemString(modules, buf);
	if (parent == NULL)
		parent = Py_None;
	return parent;
	/* We expect, but can't guarantee, if parent != None, that:
	   - parent.__name__ == buf
	   - parent.__dict__ is globals
	   If this is violated...  Who cares? */
}
#endif /* SYMBIAN */

/* altmod is either None or same as mod */
static PyObject *
load_next(PyObject *mod, PyObject *altmod, char **p_name, char *buf,
	  int *p_buflen)
{
	char *name = *p_name;
	char *dot = strchr(name, '.');
	size_t len;
	char *p;
	PyObject *result;

	if (dot == NULL) {
		*p_name = NULL;
		len = strlen(name);
	}
	else {
		*p_name = dot+1;
		len = dot-name;
	}
	if (len == 0) {
		PyErr_SetString(PyExc_ValueError,
				"Empty module name");
		return NULL;
	}

	p = buf + *p_buflen;
	if (p != buf)
		*p++ = '.';
	if (p+len-buf >= MAXPATHLEN) {
		PyErr_SetString(PyExc_ValueError,
				"Module name too long");
		return NULL;
	}
	strncpy(p, name, len);
	p[len] = '\0';
	*p_buflen = p+len-buf;

	result = import_submodule(mod, p, buf);
	if (result == Py_None && altmod != mod) {
		Py_DECREF(result);
		/* Here, altmod must be None and mod must not be None */
		result = import_submodule(altmod, p, p);
		if (result != NULL && result != Py_None) {
			if (mark_miss(buf) != 0) {
				Py_DECREF(result);
				return NULL;
			}
			strncpy(buf, name, len);
			buf[len] = '\0';
			*p_buflen = len;
		}
	}
	if (result == NULL)
		return NULL;

	if (result == Py_None) {
		Py_DECREF(result);
		PyErr_Format(PyExc_ImportError,
			     "No module named %.200s", name);
		return NULL;
	}

	return result;
}

static int
mark_miss(char *name)
{
	PyObject *modules = PyImport_GetModuleDict();
	return PyDict_SetItemString(modules, name, Py_None);
}

static int
ensure_fromlist(PyObject *mod, PyObject *fromlist, char *buf, int buflen,
		int recursive)
{
	int i;

	if (!PyObject_HasAttrString(mod, "__path__"))
		return 1;

	for (i = 0; ; i++) {
		PyObject *item = PySequence_GetItem(fromlist, i);
		int hasit;
		if (item == NULL) {
			if (PyErr_ExceptionMatches(PyExc_IndexError)) {
				PyErr_Clear();
				return 1;
			}
			return 0;
		}
		if (!PyString_Check(item)) {
			PyErr_SetString(PyExc_TypeError,
					"Item in ``from list'' not a string");
			Py_DECREF(item);
			return 0;
		}
		if (PyString_AS_STRING(item)[0] == '*') {
			PyObject *all;
			Py_DECREF(item);
			/* See if the package defines __all__ */
			if (recursive)
				continue; /* Avoid endless recursion */
			all = PyObject_GetAttrString(mod, "__all__");
			if (all == NULL)
				PyErr_Clear();
			else {
				if (!ensure_fromlist(mod, all, buf, buflen, 1))
					return 0;
				Py_DECREF(all);
			}
			continue;
		}
		hasit = PyObject_HasAttr(mod, item);
		if (!hasit) {
			char *subname = PyString_AS_STRING(item);
			PyObject *submod;
			char *p;
			if (buflen + strlen(subname) >= MAXPATHLEN) {
				PyErr_SetString(PyExc_ValueError,
						"Module name too long");
				Py_DECREF(item);
				return 0;
			}
			p = buf + buflen;
			*p++ = '.';
			strcpy(p, subname);
			submod = import_submodule(mod, subname, buf);
			Py_XDECREF(submod);
			if (submod == NULL) {
				Py_DECREF(item);
				return 0;
			}
		}
		Py_DECREF(item);
	}