cpython/Include/methodobject.h
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

92 lines
3.1 KiB
C

/* Method object interface */
#ifndef Py_METHODOBJECT_H
#define Py_METHODOBJECT_H
#ifdef __cplusplus
extern "C" {
#endif
/* This is about the type 'builtin_function_or_method',
not Python methods in user-defined classes. See classobject.h
for the latter. */
PyAPI_DATA(PyTypeObject) PyCFunction_Type;
#define PyCFunction_Check(op) ((op)->ob_type == &PyCFunction_Type)
typedef PyObject *(*PyCFunction)(PyObject *, PyObject *);
typedef PyObject *(*PyCFunctionWithKeywords)(PyObject *, PyObject *,
PyObject *);
typedef PyObject *(*PyNoArgsFunction)(PyObject *);
PyAPI_FUNC(PyCFunction) PyCFunction_GetFunction(PyObject *);
PyAPI_FUNC(PyObject *) PyCFunction_GetSelf(PyObject *);
PyAPI_FUNC(int) PyCFunction_GetFlags(PyObject *);
/* Macros for direct access to these values. Type checks are *not*
done, so use with care. */
#define PyCFunction_GET_FUNCTION(func) \
(((PyCFunctionObject *)func) -> m_ml -> ml_meth)
#define PyCFunction_GET_SELF(func) \
(((PyCFunctionObject *)func) -> m_self)
#define PyCFunction_GET_FLAGS(func) \
(((PyCFunctionObject *)func) -> m_ml -> ml_flags)
PyAPI_FUNC(PyObject *) PyCFunction_Call(PyObject *, PyObject *, PyObject *);
struct PyMethodDef {
const char *ml_name; /* The name of the built-in function/method */
PyCFunction ml_meth; /* The C function that implements it */
int ml_flags; /* Combination of METH_xxx flags, which mostly
describe the args expected by the C func */
const char *ml_doc; /* The __doc__ attribute, or NULL */
};
typedef struct PyMethodDef PyMethodDef;
PyAPI_FUNC(PyObject *) Py_FindMethod(PyMethodDef[], PyObject *, const char *);
#define PyCFunction_New(ML, SELF) PyCFunction_NewEx((ML), (SELF), NULL)
PyAPI_FUNC(PyObject *) PyCFunction_NewEx(PyMethodDef *, PyObject *,
PyObject *);
/* Flag passed to newmethodobject */
#define METH_OLDARGS 0x0000
#define METH_VARARGS 0x0001
#define METH_KEYWORDS 0x0002
/* METH_NOARGS and METH_O must not be combined with the flags above. */
#define METH_NOARGS 0x0004
#define METH_O 0x0008
/* METH_CLASS and METH_STATIC are a little different; these control
the construction of methods for a class. These cannot be used for
functions in modules. */
#define METH_CLASS 0x0010
#define METH_STATIC 0x0020
/* METH_COEXIST allows a method to be entered eventhough a slot has
already filled the entry. When defined, the flag allows a separate
method, "__contains__" for example, to coexist with a defined
slot like sq_contains. */
#define METH_COEXIST 0x0040
typedef struct PyMethodChain {
PyMethodDef *methods; /* Methods of this type */
struct PyMethodChain *link; /* NULL or base type */
} PyMethodChain;
PyAPI_FUNC(PyObject *) Py_FindMethodInChain(PyMethodChain *, PyObject *,
const char *);
typedef struct {
PyObject_HEAD
PyMethodDef *m_ml; /* Description of the C function to call */
PyObject *m_self; /* Passed as 'self' arg to the C func, can be NULL */
PyObject *m_module; /* The __module__ attribute, can be anything */
} PyCFunctionObject;
#ifdef __cplusplus
}
#endif
#endif /* !Py_METHODOBJECT_H */