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 builtin_names:
        typ, src = builtin_names[fullname]
        return builder.add(LoadAddress(typ, src, expr.line))
    # special cases
    if fullname == 'builtins.None':
        return builder.none()
    if fullname == 'builtins.True':
        return builder.true()
    if fullname == 'builtins.False':
        return builder.false()
    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_name_expr(builder: IRBuilder, expr: NameExpr) -> Value:
    if expr.node is None:
        builder.add(RaiseStandardError(RaiseStandardError.RUNTIME_ERROR,
                                       "mypyc internal error: should be unreachable",
                                       expr.line))
        return builder.none()
    fullname = expr.node.fullname
    if fullname in builtin_names:
        typ, src = builtin_names[fullname]
        return builder.add(LoadAddress(typ, src, expr.line))
    # special cases
    if fullname == 'builtins.None':
        return builder.none()
    if fullname == 'builtins.True':
        return builder.true()
    if fullname == 'builtins.False':
        return builder.false()

    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, FuncDef and MypyFile node types.
        if isinstance(expr.node, MypyFile):
            # Load reference to a module imported inside function from
            # the modules dictionary. It would be closer to Python
            # semantics to access modules imported inside functions
            # via local variables, but this is tricky since the mypy
            # AST doesn't include a Var node for the module. We
            # instead load the module separately on each access.
            mod_dict = builder.call_c(get_module_dict_op, [], expr.line)
            obj = builder.call_c(dict_get_item_op,
                                 [mod_dict, builder.load_str(expr.node.fullname)],
                                 expr.line)
            return obj
        else:
            return builder.read(builder.get_assignment_target(expr), expr.line)

    return builder.load_global(expr)
Esempio n. 3
0
def transform_comparison_expr(builder: IRBuilder, e: ComparisonExpr) -> Value:
    # x in (...)/[...]
    # x not in (...)/[...]
    first_op = e.operators[0]
    if (first_op in ['in', 'not in']
            and len(e.operators) == 1
            and isinstance(e.operands[1], (TupleExpr, ListExpr))):
        items = e.operands[1].items
        n_items = len(items)
        # x in y -> x == y[0] or ... or x == y[n]
        # x not in y -> x != y[0] and ... and x != y[n]
        # 16 is arbitrarily chosen to limit code size
        if 1 < n_items < 16:
            if e.operators[0] == 'in':
                bin_op = 'or'
                cmp_op = '=='
            else:
                bin_op = 'and'
                cmp_op = '!='
            lhs = e.operands[0]
            mypy_file = builder.graph['builtins'].tree
            assert mypy_file is not None
            bool_type = Instance(cast(TypeInfo, mypy_file.names['bool'].node), [])
            exprs = []
            for item in items:
                expr = ComparisonExpr([cmp_op], [lhs, item])
                builder.types[expr] = bool_type
                exprs.append(expr)

            or_expr: Expression = exprs.pop(0)
            for expr in exprs:
                or_expr = OpExpr(bin_op, or_expr, expr)
                builder.types[or_expr] = bool_type
            return builder.accept(or_expr)
        # x in [y]/(y) -> x == y
        # x not in [y]/(y) -> x != y
        elif n_items == 1:
            if e.operators[0] == 'in':
                cmp_op = '=='
            else:
                cmp_op = '!='
            e.operators = [cmp_op]
            e.operands[1] = items[0]
        # x in []/() -> False
        # x not in []/() -> True
        elif n_items == 0:
            if e.operators[0] == 'in':
                return builder.false()
            else:
                return builder.true()

    if first_op in ('is', 'is not') and len(e.operators) == 1:
        right = e.operands[1]
        if isinstance(right, NameExpr) and right.fullname == 'builtins.None':
            # Special case 'is None' / 'is not None'.
            return translate_is_none(builder, e.operands[0], negated=first_op != 'is')

    # TODO: Don't produce an expression when used in conditional context
    # All of the trickiness here is due to support for chained conditionals
    # (`e1 < e2 > e3`, etc). `e1 < e2 > e3` is approximately equivalent to
    # `e1 < e2 and e2 > e3` except that `e2` is only evaluated once.
    expr_type = builder.node_type(e)

    # go(i, prev) generates code for `ei opi e{i+1} op{i+1} ... en`,
    # assuming that prev contains the value of `ei`.
    def go(i: int, prev: Value) -> Value:
        if i == len(e.operators) - 1:
            return transform_basic_comparison(
                builder, e.operators[i], prev, builder.accept(e.operands[i + 1]), e.line)

        next = builder.accept(e.operands[i + 1])
        return builder.builder.shortcircuit_helper(
            'and', expr_type,
            lambda: transform_basic_comparison(
                builder, e.operators[i], prev, next, e.line),
            lambda: go(i + 1, next),
            e.line)

    return go(0, builder.accept(e.operands[0]))