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 *.

1 files changed, 1 insertions, 1 deletions

diff --git a/Include/moduleobject.h b/Include/moduleobject.h
index 0f67da3ccd..3d278af873 100644
--- a/Include/moduleobject.h
+++ b/Include/moduleobject.h
@@ -12,7 +12,7 @@ PyAPI_DATA(PyTypeObject) PyModule_Type;
 #define PyModule_Check(op) PyObject_TypeCheck(op, &PyModule_Type)
 #define PyModule_CheckExact(op) ((op)->ob_type == &PyModule_Type)
 
-PyAPI_FUNC(PyObject *) PyModule_New(char *);
+PyAPI_FUNC(PyObject *) PyModule_New(const char *);
 PyAPI_FUNC(PyObject *) PyModule_GetDict(PyObject *);
 PyAPI_FUNC(char *) PyModule_GetName(PyObject *);
 PyAPI_FUNC(char *) PyModule_GetFilename(PyObject *);