cpython/Objects/methodobject.c
Jeremy Hylton af68c874a6 Add const to several API functions that take char *.
In C++, it's an error to pass a string literal to a char* function
without a const_cast().  Rather than require every C++ extension
module to put a cast around string literals, fix the API to state the
const-ness.

I focused on parts of the API where people usually pass literals:
PyArg_ParseTuple() and friends, Py_BuildValue(), PyMethodDef, the type
slots, etc.  Predictably, there were a large set of functions that
needed to be fixed as a result of these changes.  The most pervasive
change was to make the keyword args list passed to
PyArg_ParseTupleAndKewords() to be a const char *kwlist[].

One cast was required as a result of the changes:  A type object
mallocs the memory for its tp_doc slot and later frees it.
PyTypeObject says that tp_doc is const char *; but if the type was
created by type_new(), we know it is safe to cast to char *.
2005-12-10 18:50:16 +00:00

375 lines
8.1 KiB
C

/* Method object implementation */
#include "Python.h"
#include "structmember.h"
static PyCFunctionObject *free_list = NULL;
PyObject *
PyCFunction_NewEx(PyMethodDef *ml, PyObject *self, PyObject *module)
{
PyCFunctionObject *op;
op = free_list;
if (op != NULL) {
free_list = (PyCFunctionObject *)(op->m_self);
PyObject_INIT(op, &PyCFunction_Type);
}
else {
op = PyObject_GC_New(PyCFunctionObject, &PyCFunction_Type);
if (op == NULL)
return NULL;
}
op->m_ml = ml;
Py_XINCREF(self);
op->m_self = self;
Py_XINCREF(module);
op->m_module = module;
_PyObject_GC_TRACK(op);
return (PyObject *)op;
}
PyCFunction
PyCFunction_GetFunction(PyObject *op)
{
if (!PyCFunction_Check(op)) {
PyErr_BadInternalCall();
return NULL;
}
return ((PyCFunctionObject *)op) -> m_ml -> ml_meth;
}
PyObject *
PyCFunction_GetSelf(PyObject *op)
{
if (!PyCFunction_Check(op)) {
PyErr_BadInternalCall();
return NULL;
}
return ((PyCFunctionObject *)op) -> m_self;
}
int
PyCFunction_GetFlags(PyObject *op)
{
if (!PyCFunction_Check(op)) {
PyErr_BadInternalCall();
return -1;
}
return ((PyCFunctionObject *)op) -> m_ml -> ml_flags;
}
PyObject *
PyCFunction_Call(PyObject *func, PyObject *arg, PyObject *kw)
{
PyCFunctionObject* f = (PyCFunctionObject*)func;
PyCFunction meth = PyCFunction_GET_FUNCTION(func);
PyObject *self = PyCFunction_GET_SELF(func);
int size;
switch (PyCFunction_GET_FLAGS(func) & ~(METH_CLASS | METH_STATIC | METH_COEXIST)) {
case METH_VARARGS:
if (kw == NULL || PyDict_Size(kw) == 0)
return (*meth)(self, arg);
break;
case METH_VARARGS | METH_KEYWORDS:
case METH_OLDARGS | METH_KEYWORDS:
return (*(PyCFunctionWithKeywords)meth)(self, arg, kw);
case METH_NOARGS:
if (kw == NULL || PyDict_Size(kw) == 0) {
size = PyTuple_GET_SIZE(arg);
if (size == 0)
return (*meth)(self, NULL);
PyErr_Format(PyExc_TypeError,
"%.200s() takes no arguments (%d given)",
f->m_ml->ml_name, size);
return NULL;
}
break;
case METH_O:
if (kw == NULL || PyDict_Size(kw) == 0) {
size = PyTuple_GET_SIZE(arg);
if (size == 1)
return (*meth)(self, PyTuple_GET_ITEM(arg, 0));
PyErr_Format(PyExc_TypeError,
"%.200s() takes exactly one argument (%d given)",
f->m_ml->ml_name, size);
return NULL;
}
break;
case METH_OLDARGS:
/* the really old style */
if (kw == NULL || PyDict_Size(kw) == 0) {
size = PyTuple_GET_SIZE(arg);
if (size == 1)
arg = PyTuple_GET_ITEM(arg, 0);
else if (size == 0)
arg = NULL;
return (*meth)(self, arg);
}
break;
default:
PyErr_BadInternalCall();
return NULL;
}
PyErr_Format(PyExc_TypeError, "%.200s() takes no keyword arguments",
f->m_ml->ml_name);
return NULL;
}
/* Methods (the standard built-in methods, that is) */
static void
meth_dealloc(PyCFunctionObject *m)
{
_PyObject_GC_UNTRACK(m);
Py_XDECREF(m->m_self);
Py_XDECREF(m->m_module);
m->m_self = (PyObject *)free_list;
free_list = m;
}
static PyObject *
meth_get__doc__(PyCFunctionObject *m, void *closure)
{
const char *doc = m->m_ml->ml_doc;
if (doc != NULL)
return PyString_FromString(doc);
Py_INCREF(Py_None);
return Py_None;
}
static PyObject *
meth_get__name__(PyCFunctionObject *m, void *closure)
{
return PyString_FromString(m->m_ml->ml_name);
}
static int
meth_traverse(PyCFunctionObject *m, visitproc visit, void *arg)
{
int err;
if (m->m_self != NULL) {
err = visit(m->m_self, arg);
if (err)
return err;
}
if (m->m_module != NULL) {
err = visit(m->m_module, arg);
if (err)
return err;
}
return 0;
}
static PyObject *
meth_get__self__(PyCFunctionObject *m, void *closure)
{
PyObject *self;
if (PyEval_GetRestricted()) {
PyErr_SetString(PyExc_RuntimeError,
"method.__self__ not accessible in restricted mode");
return NULL;
}
self = m->m_self;
if (self == NULL)
self = Py_None;
Py_INCREF(self);
return self;
}
static PyGetSetDef meth_getsets [] = {
{"__doc__", (getter)meth_get__doc__, NULL, NULL},
{"__name__", (getter)meth_get__name__, NULL, NULL},
{"__self__", (getter)meth_get__self__, NULL, NULL},
{0}
};
#define OFF(x) offsetof(PyCFunctionObject, x)
static PyMemberDef meth_members[] = {
{"__module__", T_OBJECT, OFF(m_module), WRITE_RESTRICTED},
{NULL}
};
static PyObject *
meth_repr(PyCFunctionObject *m)
{
if (m->m_self == NULL)
return PyString_FromFormat("<built-in function %s>",
m->m_ml->ml_name);
return PyString_FromFormat("<built-in method %s of %s object at %p>",
m->m_ml->ml_name,
m->m_self->ob_type->tp_name,
m->m_self);
}
static int
meth_compare(PyCFunctionObject *a, PyCFunctionObject *b)
{
if (a->m_self != b->m_self)
return (a->m_self < b->m_self) ? -1 : 1;
if (a->m_ml->ml_meth == b->m_ml->ml_meth)
return 0;
if (strcmp(a->m_ml->ml_name, b->m_ml->ml_name) < 0)
return -1;
else
return 1;
}
static long
meth_hash(PyCFunctionObject *a)
{
long x,y;
if (a->m_self == NULL)
x = 0;
else {
x = PyObject_Hash(a->m_self);
if (x == -1)
return -1;
}
y = _Py_HashPointer((void*)(a->m_ml->ml_meth));
if (y == -1)
return -1;
x ^= y;
if (x == -1)
x = -2;
return x;
}
PyTypeObject PyCFunction_Type = {
PyObject_HEAD_INIT(&PyType_Type)
0,
"builtin_function_or_method",
sizeof(PyCFunctionObject),
0,
(destructor)meth_dealloc, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
(cmpfunc)meth_compare, /* tp_compare */
(reprfunc)meth_repr, /* tp_repr */
0, /* tp_as_number */
0, /* tp_as_sequence */
0, /* tp_as_mapping */
(hashfunc)meth_hash, /* tp_hash */
PyCFunction_Call, /* tp_call */
0, /* tp_str */
PyObject_GenericGetAttr, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
0, /* tp_doc */
(traverseproc)meth_traverse, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
0, /* tp_methods */
meth_members, /* tp_members */
meth_getsets, /* tp_getset */
0, /* tp_base */
0, /* tp_dict */
};
/* List all methods in a chain -- helper for findmethodinchain */
static PyObject *
listmethodchain(PyMethodChain *chain)
{
PyMethodChain *c;
PyMethodDef *ml;
int i, n;
PyObject *v;
n = 0;
for (c = chain; c != NULL; c = c->link) {
for (ml = c->methods; ml->ml_name != NULL; ml++)
n++;
}
v = PyList_New(n);
if (v == NULL)
return NULL;
i = 0;
for (c = chain; c != NULL; c = c->link) {
for (ml = c->methods; ml->ml_name != NULL; ml++) {
PyList_SetItem(v, i, PyString_FromString(ml->ml_name));
i++;
}
}
if (PyErr_Occurred()) {
Py_DECREF(v);
return NULL;
}
PyList_Sort(v);
return v;
}
/* Find a method in a method chain */
PyObject *
Py_FindMethodInChain(PyMethodChain *chain, PyObject *self, const char *name)
{
if (name[0] == '_' && name[1] == '_') {
if (strcmp(name, "__methods__") == 0)
return listmethodchain(chain);
if (strcmp(name, "__doc__") == 0) {
const char *doc = self->ob_type->tp_doc;
if (doc != NULL)
return PyString_FromString(doc);
}
}
while (chain != NULL) {
PyMethodDef *ml = chain->methods;
for (; ml->ml_name != NULL; ml++) {
if (name[0] == ml->ml_name[0] &&
strcmp(name+1, ml->ml_name+1) == 0)
/* XXX */
return PyCFunction_New(ml, self);
}
chain = chain->link;
}
PyErr_SetString(PyExc_AttributeError, name);
return NULL;
}
/* Find a method in a single method list */
PyObject *
Py_FindMethod(PyMethodDef *methods, PyObject *self, const char *name)
{
PyMethodChain chain;
chain.methods = methods;
chain.link = NULL;
return Py_FindMethodInChain(&chain, self, name);
}
/* Clear out the free list */
void
PyCFunction_Fini(void)
{
while (free_list) {
PyCFunctionObject *v = free_list;
free_list = (PyCFunctionObject *)(v->m_self);
PyObject_GC_Del(v);
}
}
/* PyCFunction_New() is now just a macro that calls PyCFunction_NewEx(),
but it's part of the API so we need to keep a function around that
existing C extensions can call.
*/
#undef PyCFunction_New
PyAPI_FUNC(PyObject *) PyCFunction_New(PyMethodDef *, PyObject *);
PyObject *
PyCFunction_New(PyMethodDef *ml, PyObject *self)
{
return PyCFunction_NewEx(ml, self, NULL);
}