Esempio n. 1
0
def transform_name_expr(builder: IRBuilder, expr: NameExpr) -> Value:
    assert expr.node, "RefExpr not resolved"
    fullname = expr.node.fullname
    if fullname in name_ref_ops:
        # Use special access op for this particular name.
        desc = name_ref_ops[fullname]
        assert desc.result_type is not None
        return builder.add(PrimitiveOp([], desc, expr.line))

    if isinstance(expr.node, Var) and expr.node.is_final:
        value = builder.emit_load_final(
            expr.node,
            fullname,
            expr.name,
            builder.is_native_ref_expr(expr),
            builder.types[expr],
            expr.line,
        )
        if value is not None:
            return value

    if isinstance(expr.node,
                  MypyFile) and expr.node.fullname in builder.imports:
        return builder.load_module(expr.node.fullname)

    # If the expression is locally defined, then read the result from the corresponding
    # assignment target and return it. Otherwise if the expression is a global, load it from
    # the globals dictionary.
    # Except for imports, that currently always happens in the global namespace.
    if expr.kind == LDEF and not (isinstance(expr.node, Var)
                                  and expr.node.is_suppressed_import):
        # Try to detect and error when we hit the irritating mypy bug
        # where a local variable is cast to None. (#5423)
        if (isinstance(expr.node, Var)
                and is_none_rprimitive(builder.node_type(expr))
                and expr.node.is_inferred):
            builder.error(
                "Local variable '{}' has inferred type None; add an annotation"
                .format(expr.node.name), expr.node.line)

        # TODO: Behavior currently only defined for Var and FuncDef node types.
        return builder.read(builder.get_assignment_target(expr), expr.line)

    return builder.load_global(expr)
Esempio n. 2
0
def transform_class_def(builder: IRBuilder, cdef: ClassDef) -> None:
    ir = builder.mapper.type_to_ir[cdef.info]

    # We do this check here because the base field of parent
    # classes aren't necessarily populated yet at
    # prepare_class_def time.
    if any(ir.base_mro[i].base != ir. base_mro[i + 1] for i in range(len(ir.base_mro) - 1)):
        builder.error("Non-trait MRO must be linear", cdef.line)

    if ir.allow_interpreted_subclasses:
        for parent in ir.mro:
            if not parent.allow_interpreted_subclasses:
                builder.error(
                    'Base class "{}" does not allow interpreted subclasses'.format(
                        parent.fullname), cdef.line)

    # Currently, we only create non-extension classes for classes that are
    # decorated or inherit from Enum. Classes decorated with @trait do not
    # apply here, and are handled in a different way.
    if ir.is_ext_class:
        # If the class is not decorated, generate an extension class for it.
        type_obj = allocate_class(builder, cdef)  # type: Optional[Value]
        non_ext = None  # type: Optional[NonExtClassInfo]
        dataclass_non_ext = dataclass_non_ext_info(builder, cdef)
    else:
        non_ext_bases = populate_non_ext_bases(builder, cdef)
        non_ext_metaclass = find_non_ext_metaclass(builder, cdef, non_ext_bases)
        non_ext_dict = setup_non_ext_dict(builder, cdef, non_ext_metaclass, non_ext_bases)
        # We populate __annotations__ for non-extension classes
        # because dataclasses uses it to determine which attributes to compute on.
        # TODO: Maybe generate more precise types for annotations
        non_ext_anns = builder.primitive_op(new_dict_op, [], cdef.line)
        non_ext = NonExtClassInfo(non_ext_dict, non_ext_bases, non_ext_anns, non_ext_metaclass)
        dataclass_non_ext = None
        type_obj = None

    attrs_to_cache = []  # type: List[Lvalue]

    for stmt in cdef.defs.body:
        if isinstance(stmt, OverloadedFuncDef) and stmt.is_property:
            if not ir.is_ext_class:
                # properties with both getters and setters in non_extension
                # classes not supported
                builder.error("Property setters not supported in non-extension classes",
                           stmt.line)
            for item in stmt.items:
                with builder.catch_errors(stmt.line):
                    transform_method(builder, cdef, non_ext, get_func_def(item))
        elif isinstance(stmt, (FuncDef, Decorator, OverloadedFuncDef)):
            # Ignore plugin generated methods (since they have no
            # bodies to compile and will need to have the bodies
            # provided by some other mechanism.)
            if cdef.info.names[stmt.name].plugin_generated:
                continue
            with builder.catch_errors(stmt.line):
                transform_method(builder, cdef, non_ext, get_func_def(stmt))
        elif isinstance(stmt, PassStmt):
            continue
        elif isinstance(stmt, AssignmentStmt):
            if len(stmt.lvalues) != 1:
                builder.error("Multiple assignment in class bodies not supported", stmt.line)
                continue
            lvalue = stmt.lvalues[0]
            if not isinstance(lvalue, NameExpr):
                builder.error("Only assignment to variables is supported in class bodies",
                           stmt.line)
                continue
            # We want to collect class variables in a dictionary for both real
            # non-extension classes and fake dataclass ones.
            var_non_ext = non_ext or dataclass_non_ext
            if var_non_ext:
                add_non_ext_class_attr(builder, var_non_ext, lvalue, stmt, cdef, attrs_to_cache)
                if non_ext:
                    continue
            # Variable declaration with no body
            if isinstance(stmt.rvalue, TempNode):
                continue
            # Only treat marked class variables as class variables.
            if not (is_class_var(lvalue) or stmt.is_final_def):
                continue
            typ = builder.load_native_type_object(cdef.fullname)
            value = builder.accept(stmt.rvalue)
            builder.primitive_op(
                py_setattr_op, [typ, builder.load_static_unicode(lvalue.name), value], stmt.line)
            if builder.non_function_scope() and stmt.is_final_def:
                builder.init_final_static(lvalue, value, cdef.name)
        elif isinstance(stmt, ExpressionStmt) and isinstance(stmt.expr, StrExpr):
            # Docstring. Ignore
            pass
        else:
            builder.error("Unsupported statement in class body", stmt.line)

    if not non_ext:  # That is, an extension class
        generate_attr_defaults(builder, cdef)
        create_ne_from_eq(builder, cdef)
        if dataclass_non_ext:
            assert type_obj
            dataclass_finalize(builder, cdef, dataclass_non_ext, type_obj)
    else:
        # Dynamically create the class via the type constructor
        non_ext_class = load_non_ext_class(builder, ir, non_ext, cdef.line)
        non_ext_class = load_decorated_class(builder, cdef, non_ext_class)

        # Save the decorated class
        builder.add(InitStatic(non_ext_class, cdef.name, builder.module_name, NAMESPACE_TYPE))

        # Add the non-extension class to the dict
        builder.primitive_op(dict_set_item_op,
                          [
                              builder.load_globals_dict(),
                              builder.load_static_unicode(cdef.name),
                              non_ext_class
                          ], cdef.line)

        # Cache any cachable class attributes
        cache_class_attrs(builder, attrs_to_cache, cdef)