Merge "Add checks for Kotlin keywords and operator functions."

            return

def verify_member_name_not_kotlin_keyword(clazz):

    """Prevent method names which are keywords in Kotlin."""

    # https://kotlinlang.org/docs/reference/keyword-reference.html#hard-keywords

    # This list does not include Java keywords as those are already impossible to use.

    keywords = [

        'as',

        'fun',

        'in',

        'is',

        'object',

        'typealias',

        'val',

        'var',

        'when',

    ]

    for m in clazz.methods:

        if m.name in keywords:

            error(clazz, m, None, "Method name must not be a Kotlin keyword")

    for f in clazz.fields:

        if f.name in keywords:

            error(clazz, f, None, "Field name must not be a Kotlin keyword")

def verify_method_name_not_kotlin_operator(clazz):

    """Warn about method names which become operators in Kotlin."""

    binary = set()

    def unique_binary_op(m, op):

        if op in binary:

            error(clazz, m, None, "Only one of '{0}' and '{0}Assign' methods should be present for Kotlin".format(op))

        binary.add(op)

    for m in clazz.methods:

        if 'static' in m.split:

            continue

        # https://kotlinlang.org/docs/reference/operator-overloading.html#unary-prefix-operators

        if m.name in ['unaryPlus', 'unaryMinus', 'not'] and len(m.args) == 0:

            warn(clazz, m, None, "Method can be invoked as a unary operator from Kotlin")

        # https://kotlinlang.org/docs/reference/operator-overloading.html#increments-and-decrements

        if m.name in ['inc', 'dec'] and len(m.args) == 0 and m.typ != 'void':

            # This only applies if the return type is the same or a subtype of the enclosing class, but we have no

            # practical way of checking that relationship here.

            warn(clazz, m, None, "Method can be invoked as a pre/postfix inc/decrement operator from Kotlin")

        # https://kotlinlang.org/docs/reference/operator-overloading.html#arithmetic

        if m.name in ['plus', 'minus', 'times', 'div', 'rem', 'mod', 'rangeTo'] and len(m.args) == 1:

            warn(clazz, m, None, "Method can be invoked as a binary operator from Kotlin")

            unique_binary_op(m, m.name)

        # https://kotlinlang.org/docs/reference/operator-overloading.html#in

        if m.name == 'contains' and len(m.args) == 1 and m.typ == 'boolean':

            warn(clazz, m, None, "Method can be invoked as a 'in' operator from Kotlin")

        # https://kotlinlang.org/docs/reference/operator-overloading.html#indexed

        if (m.name == 'get' and len(m.args) > 0) or (m.name == 'set' and len(m.args) > 1):

            warn(clazz, m, None, "Method can be invoked with an indexing operator from Kotlin")

        # https://kotlinlang.org/docs/reference/operator-overloading.html#invoke

        if m.name == 'invoke':

            warn(clazz, m, None, "Method can be invoked with function call syntax from Kotlin")

        # https://kotlinlang.org/docs/reference/operator-overloading.html#assignments

        if m.name in ['plusAssign', 'minusAssign', 'timesAssign', 'divAssign', 'remAssign', 'modAssign'] \

                and len(m.args) == 1 \

                and m.typ == 'void':

            warn(clazz, m, None, "Method can be invoked as a compound assignment operator from Kotlin")

            unique_binary_op(m, m.name[:-6])  # Remove 'Assign' suffix

def examine_clazz(clazz):

    """Find all style issues in the given class."""

    if clazz.pkg.name.startswith("java"): return

    verify_error(clazz)

    verify_units(clazz)

    verify_closable(clazz)

    verify_member_name_not_kotlin_keyword(clazz)

    verify_method_name_not_kotlin_operator(clazz)

def examine_stream(stream):