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python/src/object/function.cpp
2004-04-20 21:46:34 +00:00

889 lines
28 KiB
C++

// Copyright David Abrahams 2001. Permission to copy, use,
// modify, sell and distribute this software is granted provided this
// copyright notice appears in all copies. This software is provided
// "as is" without express or implied warranty, and with no claim as
// to its suitability for any purpose.
#include <boost/python/object/function.hpp>
#include <boost/python/object/function_object.hpp>
#include <boost/python/object/function_handle.hpp>
#include <boost/python/errors.hpp>
#include <boost/python/str.hpp>
#include <boost/python/object_attributes.hpp>
#include <boost/python/args.hpp>
#include <boost/python/refcount.hpp>
#include <boost/python/extract.hpp>
#include <boost/python/tuple.hpp>
#include <boost/python/list.hpp>
#include <boost/python/converter/python_type.hpp>
#include <boost/python/detail/api_placeholder.hpp>
#include <boost/python/detail/signature.hpp>
#include <boost/mpl/vector/vector10.hpp>
#include <boost/bind.hpp>
#include <algorithm>
#include <cstring>
#include <vector>
#if BOOST_PYTHON_DEBUG_ERROR_MESSAGES
# include <cstdio>
#endif
namespace boost { namespace python { namespace objects {
py_function_impl_base::~py_function_impl_base()
{
}
unsigned py_function_impl_base::max_arity() const
{
return this->min_arity();
}
extern PyTypeObject function_type;
function::function(
py_function const& implementation
#if BOOST_WORKAROUND(__EDG_VERSION__, == 245)
, python::detail::keyword const* names_and_defaults
#else
, python::detail::keyword const* const names_and_defaults
#endif
, unsigned num_keywords
)
: m_fn(implementation)
, m_nkeyword_values(0)
{
if (names_and_defaults != 0)
{
unsigned int max_arity = m_fn.max_arity();
unsigned int keyword_offset
= max_arity > num_keywords ? max_arity - num_keywords : 0;
unsigned tuple_size = num_keywords ? max_arity : 0;
m_arg_names = object(handle<>(PyTuple_New(tuple_size)));
if (num_keywords != 0)
{
for (unsigned j = 0; j < keyword_offset; ++j)
PyTuple_SET_ITEM(m_arg_names.ptr(), j, incref(Py_None));
}
for (unsigned i = 0; i < num_keywords; ++i)
{
tuple kv;
python::detail::keyword const* const p = names_and_defaults + i;
if (p->default_value)
{
kv = make_tuple(p->name, p->default_value);
++m_nkeyword_values;
}
else
{
kv = make_tuple(p->name);
}
PyTuple_SET_ITEM(
m_arg_names.ptr()
, i + keyword_offset
, incref(kv.ptr())
);
}
}
PyObject* p = this;
if (function_type.ob_type == 0)
{
function_type.ob_type = &PyType_Type;
::PyType_Ready(&function_type);
}
PyObject_INIT(p, &function_type);
}
function::~function()
{
}
PyObject* function::call(PyObject* args, PyObject* keywords) const
{
std::size_t n_unnamed_actual = PyTuple_GET_SIZE(args);
std::size_t n_keyword_actual = keywords ? PyDict_Size(keywords) : 0;
std::size_t n_actual = n_unnamed_actual + n_keyword_actual;
function const* f = this;
// Try overloads looking for a match
do
{
// Check for a plausible number of arguments
unsigned min_arity = f->m_fn.min_arity();
unsigned max_arity = f->m_fn.max_arity();
if (n_actual + f->m_nkeyword_values >= min_arity
&& n_actual <= max_arity)
{
// This will be the args that actually get passed
handle<>inner_args(allow_null(borrowed(args)));
if (n_keyword_actual > 0 // Keyword arguments were supplied
|| n_actual < min_arity) // or default keyword values are needed
{
if (f->m_arg_names.ptr() == Py_None)
{
// this overload doesn't accept keywords
inner_args = handle<>();
}
else
{
// "all keywords are none" is a special case
// indicating we will accept any number of keyword
// arguments
if (PyTuple_Size(f->m_arg_names.ptr()) == 0)
{
// no argument preprocessing
}
else if (n_actual > max_arity)
{
// too many arguments
inner_args = handle<>();
}
else
{
// build a new arg tuple, will adjust its size later
inner_args = handle<>(PyTuple_New(max_arity));
// Fill in the positional arguments
for (std::size_t i = 0; i < n_unnamed_actual; ++i)
PyTuple_SET_ITEM(inner_args.get(), i, incref(PyTuple_GET_ITEM(args, i)));
// Grab remaining arguments by name from the keyword dictionary
std::size_t n_actual_processed = n_unnamed_actual;
for (std::size_t arg_pos = n_unnamed_actual; arg_pos < max_arity ; ++arg_pos)
{
// Get the keyword[, value pair] corresponding
PyObject* kv = PyTuple_GET_ITEM(f->m_arg_names.ptr(), arg_pos);
// If there were any keyword arguments,
// look up the one we need for this
// argument position
PyObject* value = n_keyword_actual
? PyDict_GetItem(keywords, PyTuple_GET_ITEM(kv, 0))
: 0;
if (!value)
{
// Not found; check if there's a default value
if (PyTuple_GET_SIZE(kv) > 1)
value = PyTuple_GET_ITEM(kv, 1);
if (!value)
{
// still not found; matching fails
PyErr_Clear();
inner_args = handle<>();
break;
}
}
else
{
++n_actual_processed;
}
PyTuple_SET_ITEM(inner_args.get(), arg_pos, incref(value));
}
if (inner_args.get())
{
//check if we proccessed all the arguments
if(n_actual_processed < n_actual)
inner_args = handle<>();
}
}
}
}
// Call the function. Pass keywords in case it's a
// function accepting any number of keywords
PyObject* result = inner_args ? f->m_fn(inner_args.get(), keywords) : 0;
// If the result is NULL but no error was set, m_fn failed
// the argument-matching test.
// This assumes that all other error-reporters are
// well-behaved and never return NULL to python without
// setting an error.
if (result != 0 || PyErr_Occurred())
return result;
}
f = f->m_overloads.get();
}
while (f);
// None of the overloads matched; time to generate the error message
argument_error(args, keywords);
return 0;
}
inline function const * function::overloads() const
{
return this->m_overloads.get();
}
class function_signature_generator{
public:
static bool arity_cmp( function const *f1, function const *f2 )
{
return f1->m_fn.max_arity() < f2->m_fn.max_arity();
}
static bool are_seq_overloads( function const *f1, function const *f2 , bool check_docs)
{
py_function const & impl1 = f1->m_fn;
py_function const & impl2 = f2->m_fn;
//the number of parameters differs by 1
if (impl2.max_arity()-impl1.max_arity() != 1)
return false;
// if check docs then f1 shold not have docstring or have the same docstring as f2
if (check_docs && f2->doc() != f1->doc() && f1->doc())
return false;
python::detail::signature_element const* s1 = impl1.signature();
python::detail::signature_element const* s2 = impl2.signature();
size_t size = impl1.max_arity();
for (size_t i = 0; i != size; ++i)
{
//check if the argument types are the same
if (s1[i].basename() != s2[i].basename())
return false;
//return type
if (!i) continue;
//check if the argument default values are the same
if (f1->m_arg_names && f2->m_arg_names && f2->m_arg_names[i-1]!=f1->m_arg_names[i-1]
|| bool( f1->m_arg_names ) != bool( f2->m_arg_names
))
return false;
}
return true;
}
static std::vector<function const*> flatten(function const *f)
{
object name = f->name();
std::vector<function const*> res;
while (f) {
//this if takes out the not_implemented_function
if (f->name() == name)
res.push_back(f);
f=f->overloads();
}
std::sort(res.begin(),res.end(), &arity_cmp);
return res;
}
static std::vector<function const*> split_seq_overloads( const std::vector<function const *> &funcs, bool split_on_doc_change)
{
std::vector<function const*> res;
std::vector<function const*>::const_iterator fi = funcs.begin();
function const * last = *fi;
while (++fi != funcs.end()){
//check if fi starts a new chain of overloads
if (!are_seq_overloads( last, *fi, split_on_doc_change ))
res.push_back(last);
last = *fi;
}
if (last)
res.push_back(last);
return res;
}
static object raw_function_pretty_signature(function const *f, size_t n_overloads, bool cpp_types = false)
{
str res("object");
res = str("%s %s(%s)" % make_tuple( res, f->m_name, str("tuple args, dict kwds")) );
return res;
}
static const char * py_type_str(const python::detail::signature_element &s)
{
if (s.basename()==std::string("void")){
static const char * none = "None";
return none;
}
const converter::registration *r=0;
if ( (r = converter::registry::query(s.tid) ) && r->m_class_object)
return r->m_class_object->tp_name;
else if ( (r = converter::registry::query(converter::detail::strip_type_info::query(s.tid) ) ) && r->m_class_object )
return r->m_class_object->tp_name;
else{
static const char * object = "object";
return object;
}
}
static object parameter_string(const python::detail::signature_element *s, size_t n, object arg_names, bool cpp_types)
{
str param;
if (cpp_types)
{
if (s[n].basename() == 0)
{
return str("...");
}
param = str(s[n].tid.name());
if (s[n].lvalue)
param += " {lvalue}";
}
else
{
if (n) //we are processing an argument and trying to come up with a name for it
{
object kv;
if ( arg_names && (kv = arg_names[n-1]) )
param = str( " (%s)%s" % make_tuple(py_type_str(s[n]),kv[0]) );
else
param = str(" (%s)%s%d" % make_tuple(py_type_str(s[n]),"arg", n) );
}
else //we are processing the return type - how should we handle it???
param = py_type_str(s[n]);
}
//an argument - check for default value and append it
if(n && arg_names)
{
object kv(arg_names[n-1]);
if (kv && len(kv) == 2)
{
param = str("%s=%r" % make_tuple(param, kv[1]));
}
}
return param;
}
static object pretty_signature(function const *f, size_t n_overloads, bool cpp_types = false)
{
py_function
const& impl = f->m_fn;
;
python::detail::signature_element
const* s = impl.signature()
;
size_t arity = impl.max_arity();
if(arity == size_t(-1))// is this the proper raw function test?
{
return raw_function_pretty_signature(f,n_overloads,cpp_types);
}
list formal_params;
size_t n_extra_default_args=0;
for (unsigned n = 0; n <= arity; ++n)
{
str param;
formal_params.append(
parameter_string(s, n, f->m_arg_names, cpp_types)
);
// find all the arguments with default values preceeding the arity-n_overloads
if (n && f->m_arg_names)
{
object kv(f->m_arg_names[n-1]);
if (kv && len(kv) == 2)
{
//default argument preceeding the arity-n_overloads
if( n <= arity-n_overloads)
++n_extra_default_args;
}
else
//argument without default, preceeding the arity-n_overloads
if( n <= arity-n_overloads)
n_extra_default_args = 0;
}
}
if (!arity && cpp_types)
formal_params.append("void");
str ret_type (formal_params.pop(0));
if ( !cpp_types )
ret_type = str("-> "+ret_type);
n_overloads+=n_extra_default_args;
return str(
"%s %s(%s%s%s%s) %s"
% make_tuple
( cpp_types?ret_type:str("")
, f->m_name
, str(",").join(formal_params.slice(0,arity-n_overloads))
, n_overloads ? (n_overloads!=arity?str(" [,"):str("[ ")) : str()
, str(" [,").join(formal_params.slice(arity-n_overloads,arity))
, std::string(n_overloads,']')
, cpp_types?str(""):ret_type
));
}
static list function_signatures( function const * f, bool cpp_types, bool docs)
{
list signatures;
std::vector<function const*> funcs = function_signature_generator::flatten( f);
std::vector<function const*> split_funcs = function_signature_generator::split_seq_overloads( funcs, docs);
std::vector<function const*>::const_iterator sfi=split_funcs.begin(), fi;
size_t n_overloads=0;
for (fi=funcs.begin(); fi!=funcs.end(); ++fi)
{
if(*sfi == *fi){
signatures.append(
(*fi)->doc() && docs
? function_signature_generator::pretty_signature(*fi, n_overloads,cpp_types)+ " : " +(*fi)->doc()
: function_signature_generator::pretty_signature(*fi, n_overloads,cpp_types)
);
++sfi;
n_overloads = 0;
}else
++n_overloads ;
}
return signatures;
}
};
object function::pretty_signature(bool cpp_types, size_t n_optional_trailing_args )const
{
function const *f = this;
return function_signature_generator::pretty_signature(this, n_optional_trailing_args, cpp_types);
}
void function::argument_error(PyObject* args, PyObject* keywords) const
{
static handle<> exception(
PyErr_NewException("Boost.Python.ArgumentError", PyExc_TypeError, 0));
object message = "Python argument types in\n %s.%s("
% make_tuple(this->m_namespace, this->m_name);
list actual_args;
for (int i = 0; i < PyTuple_Size(args); ++i)
{
char const* name = PyTuple_GetItem(args, i)->ob_type->tp_name;
actual_args.append(str(name));
}
message += str(", ").join(actual_args);
message += ")\ndid not match C++ signature:\n ";
list signatures = function_signature_generator::function_signatures(this, true/*cpp types*/, false/*no docs*/);
message += str("\n ").join(signatures);
#if BOOST_PYTHON_DEBUG_ERROR_MESSAGES
std::printf("\n--------\n%s\n--------\n", extract<const char*>(message)());
#endif
PyErr_SetObject(exception.get(), message.ptr());
throw_error_already_set();
}
void function::add_overload(handle<function> const& overload_)
{
function* parent = this;
while (parent->m_overloads)
parent = parent->m_overloads.get();
parent->m_overloads = overload_;
}
namespace
{
char const* const binary_operator_names[] =
{
"add__",
"and__",
"div__",
"divmod__",
"eq__",
"floordiv__",
"ge__",
"gt__",
"le__",
"lshift__",
"lt__",
"mod__",
"mul__",
"ne__",
"or__",
"pow__",
"radd__",
"rand__",
"rdiv__",
"rdivmod__",
"rfloordiv__",
"rlshift__",
"rmod__",
"rmul__",
"ror__",
"rpow__",
"rrshift__",
"rshift__",
"rsub__",
"rtruediv__",
"rxor__",
"sub__",
"truediv__",
"xor__"
};
struct less_cstring
{
bool operator()(char const* x, char const* y) const
{
return BOOST_CSTD_::strcmp(x,y) < 0;
}
};
inline bool is_binary_operator(char const* name)
{
return name[0] == '_'
&& name[1] == '_'
&& std::binary_search(
&binary_operator_names[0]
, binary_operator_names + sizeof(binary_operator_names)/sizeof(*binary_operator_names)
, name + 2
, less_cstring()
);
}
// Something for the end of the chain of binary operators
PyObject* not_implemented(PyObject*, PyObject*)
{
Py_INCREF(Py_NotImplemented);
return Py_NotImplemented;
}
handle<function> not_implemented_function()
{
static object keeper(
function_object(
py_function(&not_implemented, mpl::vector1<void>(), 2)
, python::detail::keyword_range())
);
return handle<function>(borrowed(downcast<function>(keeper.ptr())));
}
}
void function::add_to_namespace(
object const& name_space, char const* name_, object const& attribute)
{
str const name(name_);
PyObject* const ns = name_space.ptr();
if (attribute.ptr()->ob_type == &function_type)
{
function* new_func = downcast<function>(attribute.ptr());
PyObject* dict = 0;
if (PyClass_Check(ns))
dict = ((PyClassObject*)ns)->cl_dict;
else if (PyType_Check(ns))
dict = ((PyTypeObject*)ns)->tp_dict;
else
dict = PyObject_GetAttrString(ns, "__dict__");
if (dict == 0)
throw_error_already_set();
handle<> existing(allow_null(::PyObject_GetItem(dict, name.ptr())));
if (existing)
{
if (existing->ob_type == &function_type)
{
new_func->add_overload(
handle<function>(
borrowed(
downcast<function>(existing.get())
)
)
);
}
else if (existing->ob_type == &PyStaticMethod_Type)
{
char const* name_space_name = extract<char const*>(name_space.attr("__name__"));
::PyErr_Format(
PyExc_RuntimeError
, "Boost.Python - All overloads must be exported "
"before calling \'class_<...>(\"%s\").staticmethod(\"%s\")\'"
, name_space_name
, name_
);
throw_error_already_set();
}
}
else if (is_binary_operator(name_))
{
// Binary operators need an additional overload which
// returns NotImplemented, so that Python will try the
// __rxxx__ functions on the other operand. We add this
// when no overloads for the operator already exist.
new_func->add_overload(not_implemented_function());
}
// A function is named the first time it is added to a namespace.
if (new_func->name().ptr() == Py_None)
new_func->m_name = name;
handle<> name_space_name(
allow_null(::PyObject_GetAttrString(name_space.ptr(), "__name__")));
if (name_space_name)
new_func->m_namespace = object(name_space_name);
}
// The PyObject_GetAttrString() or PyObject_GetItem calls above may
// have left an active error
PyErr_Clear();
if (PyObject_SetAttr(ns, name.ptr(), attribute.ptr()) < 0)
throw_error_already_set();
}
void function::add_to_namespace(
object const& name_space, char const* name_, object const& attribute, char const* doc)
{
add_to_namespace(name_space, name_, attribute);
if (doc != 0)
{
object attr_copy(attribute);
attr_copy.attr("__doc__") = doc;
}
}
BOOST_PYTHON_DECL void add_to_namespace(
object const& name_space, char const* name, object const& attribute)
{
function::add_to_namespace(name_space, name, attribute);
}
BOOST_PYTHON_DECL void add_to_namespace(
object const& name_space, char const* name, object const& attribute, char const* doc)
{
function::add_to_namespace(name_space, name, attribute, doc);
}
namespace
{
struct bind_return
{
bind_return(PyObject*& result, function const* f, PyObject* args, PyObject* keywords)
: m_result(result)
, m_f(f)
, m_args(args)
, m_keywords(keywords)
{}
void operator()() const
{
m_result = m_f->call(m_args, m_keywords);
}
private:
PyObject*& m_result;
function const* m_f;
PyObject* m_args;
PyObject* m_keywords;
};
}
extern "C"
{
// Stolen from Python's funcobject.c
static PyObject *
function_descr_get(PyObject *func, PyObject *obj, PyObject *type_)
{
if (obj == Py_None)
obj = NULL;
return PyMethod_New(func, obj, type_);
}
static void
function_dealloc(PyObject* p)
{
delete static_cast<function*>(p);
}
static PyObject *
function_call(PyObject *func, PyObject *args, PyObject *kw)
{
PyObject* result = 0;
handle_exception(bind_return(result, static_cast<function*>(func), args, kw));
return result;
}
//
// Here we're using the function's tp_getset rather than its
// tp_members to set up __doc__ and __name__, because tp_members
// really depends on having a POD object type (it relies on
// offsets). It might make sense to reformulate function as a POD
// at some point, but this is much more expedient.
//
static PyObject* function_get_doc(PyObject* op, void*)
{
function const * f = downcast<function >(op);
list signatures = function_signature_generator::function_signatures(f, false/*pythonic args*/, true/*+docs*/);
return python::incref( str("\n ").join(signatures).ptr());
}
static int function_set_doc(PyObject* op, PyObject* doc, void*)
{
function* f = downcast<function>(op);
f->doc(doc ? object(python::detail::borrowed_reference(doc)) : object());
return 0;
}
static PyObject* function_get_name(PyObject* op, void*)
{
function* f = downcast<function>(op);
if (f->name().ptr() == Py_None)
return PyString_InternFromString("<unnamed Boost.Python function>");
else
return python::incref(f->name().ptr());
}
}
static PyGetSetDef function_getsetlist[] = {
{"__name__", (getter)function_get_name, 0 },
{"func_name", (getter)function_get_name, 0 },
{"__doc__", (getter)function_get_doc, (setter)function_set_doc},
{"func_doc", (getter)function_get_doc, (setter)function_set_doc},
{NULL} /* Sentinel */
};
PyTypeObject function_type = {
PyObject_HEAD_INIT(0)
0,
"Boost.Python.function",
sizeof(function),
0,
(destructor)function_dealloc, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_compare */
0, //(reprfunc)func_repr, /* tp_repr */
0, /* tp_as_number */
0, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /* tp_hash */
function_call, /* tp_call */
0, /* tp_str */
0, // PyObject_GenericGetAttr, /* tp_getattro */
0, // PyObject_GenericSetAttr, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT /* | Py_TPFLAGS_HAVE_GC */,/* tp_flags */
0, /* tp_doc */
0, // (traverseproc)func_traverse, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, //offsetof(PyFunctionObject, func_weakreflist), /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
0, /* tp_methods */
0, // func_memberlist, /* tp_members */
function_getsetlist, /* tp_getset */
0, /* tp_base */
0, /* tp_dict */
function_descr_get, /* tp_descr_get */
0, /* tp_descr_set */
0, //offsetof(PyFunctionObject, func_dict), /* tp_dictoffset */
0, /* tp_init */
0, /* tp_alloc */
0,
0 /* tp_new */
};
object function_object(
py_function const& f
, python::detail::keyword_range const& keywords)
{
return python::object(
python::detail::new_non_null_reference(
new function(
f, keywords.first, keywords.second - keywords.first)));
}
object function_object(py_function const& f)
{
return function_object(f, python::detail::keyword_range());
}
handle<> function_handle_impl(py_function const& f)
{
return python::handle<>(
allow_null(
new function(f, 0, 0)));
}
} // namespace objects
namespace detail
{
object BOOST_PYTHON_DECL make_raw_function(objects::py_function f)
{
static keyword k;
return objects::function_object(
f
, keyword_range(&k,&k));
}
void BOOST_PYTHON_DECL pure_virtual_called()
{
PyErr_SetString(PyExc_RuntimeError, "Pure virtual function called");
throw_error_already_set();
}
}
}} // namespace boost::python