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

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

These class represent the structure of the raw IDL document.
It maps 1-1 to the YAML file, and has not been checked if
it follows the rules of the IDL, etc.
"""

import itertools
from typing import Any, Dict, Iterator, List, Optional, Tuple, Union

from . import common
from . import errors


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

    def __init__(self, spec, error_collection):
        # type: (IDLSpec, 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 IDLSpec(object):
    """
    The in-memory representation of an IDL file.

    - Includes all imported files.
    """

    def __init__(self):
        # type: () -> None
        """Construct an IDL spec."""
        self.symbols = SymbolTable()  # type: SymbolTable
        self.globals = None  # type: Optional[Global]
        self.imports = None  # type: Optional[Import]
        self.server_parameters = []  # type: List[ServerParameter]
        self.configs = []  # type: List[ConfigOption]
        self.feature_flags = []  # type: List[FeatureFlag]


def parse_array_type(name):
    # type: (str) -> str
    """Parse a type name of the form 'array<type>' and extract type."""
    if not name.startswith("array<") and not name.endswith(">"):
        return None

    name = name[len("array<"):]
    name = name[:-1]

    # V1 restriction, ban nested array types to reduce scope.
    if name.startswith("array<") and name.endswith(">"):
        return None

    return name


def _zip_scalar(items, obj):
    # type: (List[Any], Any) -> Iterator[Tuple[Any, Any]]
    """Return an Iterator of (obj, list item) tuples."""
    return ((item, obj) for item in items)


def _item_and_type(dic):
    # type: (Dict[Any, List[Any]]) -> Iterator[Tuple[Any, Any]]
    """Return an Iterator of (key, value) pairs from a dictionary."""
    return itertools.chain.from_iterable((_zip_scalar(value, key) for (key, value) in dic.items()))


class SymbolTable(object):
    """
    IDL Symbol Table.

    - Contains all information to resolve commands, enums, structs, types, and server parameters.
    - Checks for duplicate names across the union of (commands, enums, types, structs)
    """

    def __init__(self):
        # type: () -> None
        """Construct an empty symbol table."""
        self.commands = []  # type: List[Command]
        self.enums = []  # type: List[Enum]
        self.structs = []  # type: List[Struct]
        self.types = []  # type: List[Type]

    def _is_duplicate(self, ctxt, location, name, duplicate_class_name):
        # type: (errors.ParserContext, common.SourceLocation, str, str) -> bool
        """Return true if the given item already exist in the symbol table."""
        for (item, entity_type) in _item_and_type({
                "command": self.commands,
                "enum": self.enums,
                "struct": self.structs,
                "type": self.types,
        }):
            if item.name == name:
                ctxt.add_duplicate_symbol_error(location, name, duplicate_class_name, entity_type)
                return True

        return False

    def add_enum(self, ctxt, idl_enum):
        # type: (errors.ParserContext, Enum) -> None
        """Add an IDL enum to the symbol table and check for duplicates."""
        if not self._is_duplicate(ctxt, idl_enum, idl_enum.name, "enum"):
            self.enums.append(idl_enum)

    def add_struct(self, ctxt, struct):
        # type: (errors.ParserContext, Struct) -> None
        """Add an IDL struct to the symbol table and check for duplicates."""
        if not self._is_duplicate(ctxt, struct, struct.name, "struct"):
            self.structs.append(struct)

    def add_type(self, ctxt, idltype):
        # type: (errors.ParserContext, Type) -> None
        """Add an IDL type to the symbol table and check for duplicates."""
        if not self._is_duplicate(ctxt, idltype, idltype.name, "type"):
            self.types.append(idltype)

    def add_command(self, ctxt, command):
        # type: (errors.ParserContext, Command) -> None
        """Add an IDL command to the symbol table and check for duplicates."""
        if not self._is_duplicate(ctxt, command, command.name, "command"):
            self.commands.append(command)

    def add_imported_symbol_table(self, ctxt, imported_symbols):
        # type: (errors.ParserContext, SymbolTable) -> None
        """
        Merge all the symbols in the imported_symbols symbol table into the symbol table.

        Marks imported structs as imported, and errors on duplicate symbols.
        """
        for command in imported_symbols.commands:
            if not self._is_duplicate(ctxt, command, command.name, "command"):
                command.imported = True
                self.commands.append(command)

        for struct in imported_symbols.structs:
            if not self._is_duplicate(ctxt, struct, struct.name, "struct"):
                struct.imported = True
                self.structs.append(struct)

        for idl_enum in imported_symbols.enums:
            if not self._is_duplicate(ctxt, idl_enum, idl_enum.name, "enum"):
                idl_enum.imported = True
                self.enums.append(idl_enum)

        for idltype in imported_symbols.types:
            self.add_type(ctxt, idltype)

    def resolve_field_type(self, ctxt, location, field_name, type_name):
        # type: (errors.ParserContext, common.SourceLocation, str, str) -> Optional[Union[Command, Enum, Struct, Type]]
        """Find the type or struct a field refers to or log an error."""
        return self._resolve_field_type(ctxt, location, field_name, type_name)

    def _resolve_field_type(self, ctxt, location, field_name, type_name):
        # type: (errors.ParserContext, common.SourceLocation, str, str) -> Optional[Union[Command, Enum, Struct, Type]]
        """Find the type or struct a field refers to or log an error."""
        # pylint: disable=too-many-return-statements

        for command in self.commands:
            if command.name == type_name:
                return command

        for idl_enum in self.enums:
            if idl_enum.name == type_name:
                return idl_enum

        for struct in self.structs:
            if struct.name == type_name:
                return struct

        for idltype in self.types:
            if idltype.name == type_name:
                return idltype

        if type_name.startswith('array<'):
            array_type_name = parse_array_type(type_name)
            if not array_type_name:
                ctxt.add_bad_array_type_name_error(location, field_name, type_name)
                return None

            return self._resolve_field_type(ctxt, location, field_name, array_type_name)

        ctxt.add_unknown_type_error(location, field_name, type_name)

        return None


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

    Not all fields may be populated. If they do not exist in the source document, they are not
    populated.
    """

    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 Import(common.SourceLocation):
    """IDL imports object."""

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct an Imports section."""
        self.imports = []  # type: List[str]

        # These are not part of the IDL syntax but are produced by the parser.
        # List of imports with structs.
        self.resolved_imports = []  # type: List[str]
        # All imports directly or indirectly included
        self.dependencies = []  # type: List[str]

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


class Type(common.SourceLocation):
    """
    Stores all type information about an IDL type.

    The fields name, description, cpp_type, and bson_serialization_type are required.
    Other fields may be populated. If they do not exist in the source document, they are not
    populated.
    """

    # pylint: disable=too-many-instance-attributes

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a Type."""
        self.name = None  # type: str
        self.description = 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.default = None  # type: str

        super(Type, 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.
    """

    # pylint: disable=too-many-instance-attributes

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a Validator."""
        # Don't lint gt/lt as bad attibute 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: str

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


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

    The fields name, and type are required.
    Other fields may be populated. If they do not exist in the source document, they are not
    populated.
    """

    # pylint: disable=too-many-instance-attributes

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a Field."""
        self.name = None  # type: str
        self.cpp_name = None  # type: str
        self.description = None  # type: str
        self.type = None  # type: str
        self.ignore = False  # type: bool
        self.optional = False  # type: bool
        self.default = None  # type: str
        self.supports_doc_sequence = False  # type: bool
        self.comparison_order = -1  # type: int
        self.validator = None  # type: Validator
        self.non_const_getter = False  # type: bool

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

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


class ChainedStruct(common.SourceLocation):
    """
    Stores all type information about an IDL chained struct.

    The fields name, and cpp_name are required.
    """

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

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


class ChainedType(common.SourceLocation):
    """
    Stores all type information about an IDL chained type.

    The fields name, and cpp_name are required.
    """

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

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


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

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

    # pylint: disable=too-many-instance-attributes

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a Struct."""
        self.name = None  # type: str
        self.description = None  # type: str
        self.strict = True  # type: bool
        self.immutable = False  # type: bool
        self.inline_chained_structs = True  # type: bool
        self.generate_comparison_operators = False  # type: bool
        self.chained_types = None  # type: List[ChainedType]
        self.chained_structs = None  # type: List[ChainedStruct]
        self.fields = None  # type: List[Field]

        # Command only property
        self.cpp_name = None  # type: str

        # Internal property that is not represented as syntax. An imported struct is read from an
        # imported file, and no code is generated for it.
        self.imported = False  # type: bool

        # Internal property: cpp_namespace from globals section
        self.cpp_namespace = None  # type: str

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


class Command(Struct):
    """
    IDL command information, a subtype of Struct.

    Namespace is required.
    """

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

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


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.value = None  # type: str

        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.type = None  # type: str
        self.values = None  # type: List[EnumValue]

        # Internal property that is not represented as syntax. An imported enum is read from an
        # imported file, and no code is generated for it.
        self.imported = False  # type: bool

        # Internal property: cpp_namespace from globals section
        self.cpp_namespace = None  # type: str

        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

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


class Expression(common.SourceLocation):
    """Description of a valid C++ expression."""

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

        self.literal = None  # type: str
        self.expr = None  # type: str
        self.is_constexpr = True  # type: bool

        super(Expression, 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

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


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

    # pylint: disable=too-many-instance-attributes

    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: List[str]
        self.description = None  # type: str
        self.cpp_vartype = None  # type: str
        self.cpp_varname = None  # type: str
        self.cpp_class = None  # type: ServerParameterClass
        self.condition = None  # type: Condition
        self.deprecated_name = []  # type: List[str]
        self.redact = False  # type: bool
        self.test_only = False  # type: bool
        self.default = None  # type: Expression

        # 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 FeatureFlag(common.SourceLocation):
    """IDL FeatureFlag information."""

    # pylint: disable=too-many-instance-attributes

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a FeatureFlag."""
        self.name = None  # type: str
        self.description = None  # type: str
        self.cpp_varname = None  # type: str
        self.default = None  # type: Expression

        super(FeatureFlag, 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):
    """Global values to apply to all ConfigOptions."""

    def __init__(self, file_name, line, column):
        # type: (str, int, int) -> None
        """Construct a ConfigGlobal."""
        self.section = None  # type: str
        self.source = []  # type: List[str]
        self.initializer = None  # type: GlobalInitializer

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


class ConfigOption(common.SourceLocation):
    """Runtime configuration setting definition."""

    # pylint: disable=too-many-instance-attributes

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

        self.duplicate_behavior = None  # type: str
        self.positional = None  # type str
        self.validator = None  # type: Validator

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