def specialize_parent_vtable(cls: ClassIR, parent: ClassIR) -> VTableEntries:
"""Generate the part of a vtable corresponding to a parent class or trait"""
updated = []
for entry in parent.vtable_entries:
if isinstance(entry, VTableMethod):
# Find the original method corresponding to this vtable entry.
# (This may not be the method in the entry, if it was overridden.)
orig_parent_method = entry.cls.get_method(entry.name)
assert orig_parent_method
method_cls = cls.get_method_and_class(entry.name)
if method_cls:
child_method, defining_cls = method_cls
# TODO: emit a wrapper for __init__ that raises or something
if (is_same_method_signature(orig_parent_method.sig, child_method.sig)
or orig_parent_method.name == '__init__'):
entry = VTableMethod(entry.cls, entry.name, child_method, entry.shadow_method)
else:
entry = VTableMethod(entry.cls, entry.name,
defining_cls.glue_methods[(entry.cls, entry.name)],
entry.shadow_method)
else:
# If it is an attribute from a trait, we need to find out
# the real class it got mixed in at and point to that.
if parent.is_trait:
_, origin_cls = cls.attr_details(entry.name)
entry = VTableAttr(origin_cls, entry.name, entry.is_setter)
updated.append(entry)
return updated
def compute_vtable(cls: ClassIR) -> None:
"""Compute the vtable structure for a class."""
if cls.vtable is not None: return
if not cls.is_generated:
cls.has_dict = any(x.inherits_python for x in cls.mro)
for t in cls.mro[1:]:
# Make sure all ancestors are processed first
compute_vtable(t)
# Merge attributes from traits into the class
if not t.is_trait:
continue
for name, typ in t.attributes.items():
if not cls.is_trait and not any(name in b.attributes for b in cls.base_mro):
cls.attributes[name] = typ
cls.vtable = {}
if cls.base:
assert cls.base.vtable is not None
cls.vtable.update(cls.base.vtable)
cls.vtable_entries = specialize_parent_vtable(cls, cls.base)
# Include the vtable from the parent classes, but handle method overrides.
entries = cls.vtable_entries
# Traits need to have attributes in the vtable, since the
# attributes can be at different places in different classes, but
# regular classes can just directly get them.
if cls.is_trait:
# Traits also need to pull in vtable entries for non-trait
# parent classes explicitly.
for t in cls.mro:
for attr in t.attributes:
if attr in cls.vtable:
continue
cls.vtable[attr] = len(entries)
entries.append(VTableAttr(t, attr, is_setter=False))
entries.append(VTableAttr(t, attr, is_setter=True))
all_traits = [t for t in cls.mro if t.is_trait]
for t in [cls] + cls.traits:
for fn in itertools.chain(t.methods.values()):
# TODO: don't generate a new entry when we overload without changing the type
if fn == cls.get_method(fn.name):
cls.vtable[fn.name] = len(entries)
# If the class contains a glue method referring to itself, that is a
# shadow glue method to support interpreted subclasses.
shadow = cls.glue_methods.get((cls, fn.name))
entries.append(VTableMethod(t, fn.name, fn, shadow))
# Compute vtables for all of the traits that the class implements
if not cls.is_trait:
for trait in all_traits:
compute_vtable(trait)
cls.trait_vtables[trait] = specialize_parent_vtable(cls, trait)
def specialize_parent_vtable(cls: ClassIR, parent: ClassIR) -> VTableEntries:
"""Generate the part of a vtable corresponding to a parent class or trait"""
updated = []
for entry in parent.vtable_entries:
# Find the original method corresponding to this vtable entry.
# (This may not be the method in the entry, if it was overridden.)
orig_parent_method = entry.cls.get_method(entry.name)
assert orig_parent_method
method_cls = cls.get_method_and_class(entry.name)
if method_cls:
child_method, defining_cls = method_cls
# TODO: emit a wrapper for __init__ that raises or something
if (is_same_method_signature(orig_parent_method.sig,
child_method.sig)
or orig_parent_method.name == '__init__'):
entry = VTableMethod(entry.cls, entry.name, child_method,
entry.shadow_method)
else:
entry = VTableMethod(
entry.cls, entry.name,
defining_cls.glue_methods[(entry.cls, entry.name)],
entry.shadow_method)
updated.append(entry)
return updated