def generate_vtable(entries: VTableEntries, vtable_name: str, emitter: Emitter,
subtables: List[Tuple[ClassIR,
str]], shadow: bool) -> None:
emitter.emit_line('CPyVTableItem {}_scratch[] = {{'.format(vtable_name))
if subtables:
emitter.emit_line('/* Array of trait vtables */')
for trait, table in subtables:
emitter.emit_line('(CPyVTableItem){}, (CPyVTableItem){},'.format(
emitter.type_struct_name(trait), table))
emitter.emit_line('/* Start of real vtable */')
for entry in entries:
if isinstance(entry, VTableMethod):
method = entry.shadow_method if shadow and entry.shadow_method else entry.method
emitter.emit_line('(CPyVTableItem){}{}{},'.format(
emitter.get_group_prefix(entry.method.decl), NATIVE_PREFIX,
method.cname(emitter.names)))
else:
cl, attr, is_setter = entry
namer = native_setter_name if is_setter else native_getter_name
emitter.emit_line('(CPyVTableItem){}{},'.format(
emitter.get_group_prefix(cl), namer(cl, attr, emitter.names)))
# msvc doesn't allow empty arrays; maybe allowing them at all is an extension?
if not entries:
emitter.emit_line('NULL')
emitter.emit_line('};')
emitter.emit_line('memcpy({name}, {name}_scratch, sizeof({name}));'.format(
name=vtable_name))
def generate_constructor_for_class(cl: ClassIR, fn: FuncDecl,
init_fn: Optional[FuncIR], setup_name: str,
vtable_name: str, emitter: Emitter) -> None:
"""Generate a native function that allocates and initializes an instance of a class."""
emitter.emit_line('{}'.format(native_function_header(fn, emitter)))
emitter.emit_line('{')
emitter.emit_line('PyObject *self = {}({});'.format(
setup_name, emitter.type_struct_name(cl)))
emitter.emit_line('if (self == NULL)')
emitter.emit_line(' return NULL;')
args = ', '.join(['self'] + [REG_PREFIX + arg.name for arg in fn.sig.args])
if init_fn is not None:
emitter.emit_line('char res = {}{}{}({});'.format(
emitter.get_group_prefix(init_fn.decl), NATIVE_PREFIX,
init_fn.cname(emitter.names), args))
emitter.emit_line('if (res == 2) {')
emitter.emit_line('Py_DECREF(self);')
emitter.emit_line('return NULL;')
emitter.emit_line('}')
# If there is a nontrivial ctor that we didn't define, invoke it via tp_init
elif len(fn.sig.args) > 1:
emitter.emit_line('int res = {}->tp_init({});'.format(
emitter.type_struct_name(cl), args))
emitter.emit_line('if (res < 0) {')
emitter.emit_line('Py_DECREF(self);')
emitter.emit_line('return NULL;')
emitter.emit_line('}')
emitter.emit_line('return self;')
emitter.emit_line('}')
def generate_len_wrapper(cl: ClassIR, fn: FuncIR, emitter: Emitter) -> str:
"""Generates a wrapper for native __len__ methods."""
name = '{}{}{}'.format(DUNDER_PREFIX, fn.name,
cl.name_prefix(emitter.names))
emitter.emit_line(
'static Py_ssize_t {name}(PyObject *self) {{'.format(name=name))
emitter.emit_line('{}retval = {}{}{}(self);'.format(
emitter.ctype_spaced(fn.ret_type), emitter.get_group_prefix(fn.decl),
NATIVE_PREFIX, fn.cname(emitter.names)))
emitter.emit_error_check('retval', fn.ret_type, 'return -1;')
if is_int_rprimitive(fn.ret_type):
emitter.emit_line('Py_ssize_t val = CPyTagged_AsSsize_t(retval);')
else:
emitter.emit_line('Py_ssize_t val = PyLong_AsSsize_t(retval);')
emitter.emit_dec_ref('retval', fn.ret_type)
emitter.emit_line('if (PyErr_Occurred()) return -1;')
emitter.emit_line('return val;')
emitter.emit_line('}')
return name
