path: root/buildscripts/idl/idl/ast.py

# Copyright (C) 2018-present MongoDB, Inc.
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"""
IDL AST classes.

Represents the derived IDL specification after type resolution in the binding pass has occurred.

This is a lossy translation from the IDL Syntax tree as the IDL AST only contains information about
the enums and structs that need code generated for them, and just enough information to do that.
"""
from abc import ABCMeta, abstractmethod
from typing import Any, Dict, List, Optional

from . import common, errors


class IDLBoundSpec(object):
    """A bound IDL document or a set of errors if parsing failed."""

    def __init__(self, spec, error_collection):
        # type: (IDLAST, errors.ParserErrorCollection) -> None
        """Must specify either an IDL document or errors, not both."""
        assert (spec is None and error_collection is not None) or (spec is not None
                                                                   and error_collection is None)
        self.spec = spec
        self.errors = error_collection


class IDLAST(object):
    """The in-memory representation of an IDL file."""

    def __init__(self):
        # type: () -> None
        """Construct an IDLAST."""
        self.globals = None  # type: Global

        self.commands = []  # type: List[Command]
        self.enums = []  # type: List[Enum]
        self.structs = []  # type: List[Struct]
        self.generic_argument_lists = []  # type: List[GenericArgumentList]
        self.generic_reply_field_lists = []  # type: List[GenericReplyFieldList]
        self.server_parameters = []  # type: List[ServerParameter]
        self.configs = []  # type: List[ConfigOption]


class Global(common.SourceLocation):
    """
    IDL global object container.

    cpp_namespace and cpp_includes are only populated if the IDL document contains these YAML nodes.
    """

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a Global."""
        self.cpp_namespace = None  # type: str
        self.cpp_includes = []  # type: List[str]
        self.configs = None  # type: ConfigGlobal

        super(Global, self).__init__(file_name, line, column)


class Type(common.SourceLocation):
    """
    IDL type information.

    The type of a struct field or command field, for the sake of C++ code generation.
    """

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a Type."""
        self.name = None  # type: str
        self.cpp_type = None  # type: str
        self.bson_serialization_type = None  # type: List[str]
        self.bindata_subtype = None  # type: str
        self.serializer = None  # type: str
        self.deserializer = None  # type: str
        self.is_enum = False  # type: bool
        self.is_array = False  # type: bool
        self.is_variant = False  # type: bool
        self.is_struct = False  # type: bool
        self.variant_types = []  # type: List[Type]
        # A variant can have at most one alternative type which is a struct. Otherwise, if we saw
        # a sub-object while parsing BSON, we wouldn't know which struct to interpret it as.
        self.variant_struct_type = None  # type: Type
        self.deserialize_with_tenant = False  # type: bool
        super(Type, self).__init__(file_name, line, column)


class Struct(common.SourceLocation):
    """
    IDL struct information.

    All fields are either required or have a non-None default.

    NOTE: We use this class to generate a struct's C++ class and method definitions. When a field
    has a struct type (or a field is an array of structs or a variant that can be a struct), we
    represent that struct type using ast.Type with is_struct=True.
    """

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a struct."""
        self.name = None  # type: str
        self.cpp_name = None  # type: str
        self.qualified_cpp_name = None  # type: str
        self.description = None  # type: str
        self.strict = True  # type: bool
        self.immutable = False  # type: bool
        self.inline_chained_structs = False  # type: bool
        self.generate_comparison_operators = False  # type: bool
        self.fields = []  # type: List[Field]
        self.allow_global_collection_name = False  # type: bool
        self.non_const_getter = False  # type: bool
        self.cpp_validator_func = None  # type: str
        self.is_command_reply = False  # type: bool
        super(Struct, self).__init__(file_name, line, column)


class Expression(common.SourceLocation):
    """Literal of C++ expression representation."""

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct an Expression."""
        self.expr = None  # type: str
        self.validate_constexpr = True  # type: bool
        self.export = False  # type: bool

        super(Expression, self).__init__(file_name, line, column)


class Validator(common.SourceLocation):
    """
    An instance of a validator for a field.

    The validator must include at least one of the defined validation predicates.
    If more than one is included, they must ALL evaluate to true.
    """

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a Validator."""
        # Don't lint gt/lt as bad attribute names.
        # pylint: disable=C0103
        self.gt = None  # type: Expression
        self.lt = None  # type: Expression
        self.gte = None  # type: Expression
        self.lte = None  # type: Expression
        self.callback = None  # type: Optional[str]

        super(Validator, self).__init__(file_name, line, column)


class Field(common.SourceLocation):
    """
    An instance of a field in a struct.

    Name is always populated.
    Not all fields are set, it depends on the input document.
    """

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a Field."""
        self.name = None  # type: str
        self.description = None  # type: str
        self.cpp_name = None  # type: str
        self.optional = False  # type: bool
        self.ignore = False  # type: bool
        self.chained = False  # type: bool
        self.comparison_order = -1  # type: int
        self.non_const_getter = False  # type: bool
        self.stability = None  # type: Optional[str]
        self.default = None  # type: str
        self.type = None  # type: Type
        self.always_serialize = False  # type: bool

        # Properties specific to fields which are arrays.
        self.supports_doc_sequence = False  # type: bool

        # Properties specific to fields inlined from chained_structs
        self.chained_struct_field = None  # type: Field

        # Internal fields - not generated by parser
        self.serialize_op_msg_request_only = False  # type: bool
        self.constructed = False  # type: bool

        # Validation rules.
        self.validator = None  # type: Optional[Validator]

        super(Field, self).__init__(file_name, line, column)


class Privilege(common.SourceLocation):
    """IDL privilege information."""

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct an Privilege."""

        self.resource_pattern = None  # type: str
        self.action_type = None  # type: List[str]

        super(Privilege, self).__init__(file_name, line, column)


class AccessCheck(common.SourceLocation):
    """IDL commmand access check information."""

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct an AccessCheck."""

        self.check = None  # type: str
        self.privilege = None  # type: Privilege

        super(AccessCheck, self).__init__(file_name, line, column)


class Command(Struct):
    """
    IDL commmand information.

    All fields are either required or have a non-None default.
    """

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a command."""
        self.namespace = None  # type: str
        self.command_name = None  # type: str
        self.command_alias = None  # type: str
        self.command_field = None  # type: Field
        self.reply_type = None  # type: Field
        self.api_version = ""  # type: str
        self.is_deprecated = False  # type: bool
        self.access_checks = None  # type: List[AccessCheck]
        super(Command, self).__init__(file_name, line, column)


class FieldListBase(common.SourceLocation, metaclass=ABCMeta):
    """Base class for generic argument or reply field lists."""

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a field list."""
        self.name = None  # type: str
        self.cpp_name = None  # type: str
        self.description = None  # type: str
        self.fields = []  # type: List[FieldListEntry]
        super(FieldListBase, self).__init__(file_name, line, column)

    @abstractmethod
    def get_should_forward_name(self):
        # type: () -> str
        """Get the name of the shard-forwarding rule for this generic argument or reply field."""
        pass


class GenericArgumentList(FieldListBase):
    """IDL generic argument list."""

    def get_should_forward_name(self):
        # type: () -> str
        """Get the name of the shard-forwarding rule for a generic argument."""
        return "shouldForwardToShards"


class GenericReplyFieldList(FieldListBase):
    """IDL generic reply field list."""

    def get_should_forward_name(self):
        # type: () -> str
        """Get the name of the shard-forwarding rule for a generic reply field."""
        return "shouldForwardFromShards"


class FieldListEntry(common.SourceLocation):
    """Options for a field in a field list."""

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a FieldListEntry."""
        self.name = None  # type: str
        self.forward_to_shards = False  # type: bool
        self.forward_from_shards = False  # type: bool
        super(FieldListEntry, self).__init__(file_name, line, column)

    def get_should_forward(self):
        """Get the shard-forwarding rule for a generic argument or reply field."""
        assert not (self.forward_to_shards and self.forward_from_shards), \
            "Only FieldListEntry.forward_to_shards or forward_from_shards should be set"

        return self.forward_to_shards or self.forward_from_shards


class EnumValue(common.SourceLocation):
    """
    IDL Enum Value information.

    All fields are either required or have a non-None default.
    """

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct an Enum."""
        self.name = None  # type: str
        self.description = None  # type: str
        self.value = None  # type: str
        self.extra_data = None  # type: Dict[str, Any]

        super(EnumValue, self).__init__(file_name, line, column)


class Enum(common.SourceLocation):
    """
    IDL Enum information.

    All fields are either required or have a non-None default.
    """

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct an Enum."""
        self.name = None  # type: str
        self.description = None  # type: str
        self.cpp_namespace = None  # type: str
        self.type = None  # type: str
        self.values = []  # type: List[EnumValue]

        super(Enum, self).__init__(file_name, line, column)


class Condition(common.SourceLocation):
    """Condition(s) for a ServerParameter or ConfigOption."""

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a Condition."""
        self.expr = None  # type: str
        self.constexpr = None  # type: str
        self.preprocessor = None  # type: str
        self.feature_flag = None  # type: str

        super(Condition, self).__init__(file_name, line, column)


class ServerParameterClass(common.SourceLocation):
    """ServerParameter as C++ class specialization."""

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a ServerParameterClass."""

        self.name = None  # type: str
        self.data = None  # type: str
        self.override_ctor = False  # type: bool
        self.override_set = False  # type: bool
        self.override_validate = False  # type: bool

        super(ServerParameterClass, self).__init__(file_name, line, column)


class ServerParameter(common.SourceLocation):
    """IDL ServerParameter setting."""

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a ServerParameter."""
        self.name = None  # type: str
        self.set_at = None  # type: str
        self.description = None  # type: str
        self.cpp_class = None  # type: ServerParameterClass
        self.cpp_vartype = None  # type: str
        self.cpp_varname = None  # type: str
        self.condition = None  # type: Condition
        self.redact = False  # type: bool
        self.test_only = False  # type: bool
        self.deprecated_name = []  # type: List[str]
        self.default = None  # type: Expression
        self.feature_flag = False  # type: bool

        # Only valid if cpp_varname is specified.
        self.validator = None  # type: Validator
        self.on_update = None  # type: str

        super(ServerParameter, self).__init__(file_name, line, column)


class GlobalInitializer(common.SourceLocation):
    """Initializer details for custom registration/storage."""

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a GlobalInitializer."""

        self.name = None  # type: str
        self.register = None  # type: str
        self.store = None  # type: str

        super(GlobalInitializer, self).__init__(file_name, line, column)


class ConfigGlobal(common.SourceLocation):
    """IDL ConfigOption Globals."""

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a ConfigGlobal."""

        # Other config globals are consumed in bind phase.
        self.initializer = None  # type: GlobalInitializer

        super(ConfigGlobal, self).__init__(file_name, line, column)


class ConfigOption(common.SourceLocation):
    """IDL ConfigOption setting."""

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a ConfigOption."""
        self.name = None  # type: str
        self.short_name = None  # type: str
        self.deprecated_name = []  # type: List[str]
        self.deprecated_short_name = []  # type: List[str]

        self.description = None  # type: Expression
        self.section = None  # type: str
        self.arg_vartype = None  # type: str
        self.cpp_vartype = None  # type: str
        self.cpp_varname = None  # type: str
        self.condition = None  # type: Condition

        self.conflicts = []  # type: List[str]
        self.requires = []  # type: List[str]
        self.hidden = False  # type: bool
        self.redact = False  # type: bool
        self.default = None  # type: Expression
        self.implicit = None  # type: Expression
        self.source = None  # type: str
        self.canonicalize = None  # type: str

        self.duplicates_append = False  # type: bool
        self.positional_start = None  # type: int
        self.positional_end = None  # type: int
        self.validator = None  # type: Validator

        super(ConfigOption, self).__init__(file_name, line, column)