aboutsummaryrefslogtreecommitdiffstats
path: root/scripts/qapi/expr.py
diff options
context:
space:
mode:
Diffstat (limited to 'scripts/qapi/expr.py')
-rw-r--r--scripts/qapi/expr.py694
1 files changed, 694 insertions, 0 deletions
diff --git a/scripts/qapi/expr.py b/scripts/qapi/expr.py
new file mode 100644
index 000000000..3cb389e87
--- /dev/null
+++ b/scripts/qapi/expr.py
@@ -0,0 +1,694 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright IBM, Corp. 2011
+# Copyright (c) 2013-2021 Red Hat Inc.
+#
+# Authors:
+# Anthony Liguori <aliguori@us.ibm.com>
+# Markus Armbruster <armbru@redhat.com>
+# Eric Blake <eblake@redhat.com>
+# Marc-André Lureau <marcandre.lureau@redhat.com>
+# John Snow <jsnow@redhat.com>
+#
+# This work is licensed under the terms of the GNU GPL, version 2.
+# See the COPYING file in the top-level directory.
+
+"""
+Normalize and validate (context-free) QAPI schema expression structures.
+
+`QAPISchemaParser` parses a QAPI schema into abstract syntax trees
+consisting of dict, list, str, bool, and int nodes. This module ensures
+that these nested structures have the correct type(s) and key(s) where
+appropriate for the QAPI context-free grammar.
+
+The QAPI schema expression language allows for certain syntactic sugar;
+this module also handles the normalization process of these nested
+structures.
+
+See `check_exprs` for the main entry point.
+
+See `schema.QAPISchema` for processing into native Python data
+structures and contextual semantic validation.
+"""
+
+import re
+from typing import (
+ Collection,
+ Dict,
+ Iterable,
+ List,
+ Optional,
+ Union,
+ cast,
+)
+
+from .common import c_name
+from .error import QAPISemError
+from .parser import QAPIDoc
+from .source import QAPISourceInfo
+
+
+# Deserialized JSON objects as returned by the parser.
+# The values of this mapping are not necessary to exhaustively type
+# here (and also not practical as long as mypy lacks recursive
+# types), because the purpose of this module is to interrogate that
+# type.
+_JSONObject = Dict[str, object]
+
+
+# See check_name_str(), below.
+valid_name = re.compile(r'(__[a-z0-9.-]+_)?'
+ r'(x-)?'
+ r'([a-z][a-z0-9_-]*)$', re.IGNORECASE)
+
+
+def check_name_is_str(name: object,
+ info: QAPISourceInfo,
+ source: str) -> None:
+ """
+ Ensure that ``name`` is a ``str``.
+
+ :raise QAPISemError: When ``name`` fails validation.
+ """
+ if not isinstance(name, str):
+ raise QAPISemError(info, "%s requires a string name" % source)
+
+
+def check_name_str(name: str, info: QAPISourceInfo, source: str) -> str:
+ """
+ Ensure that ``name`` is a valid QAPI name.
+
+ A valid name consists of ASCII letters, digits, ``-``, and ``_``,
+ starting with a letter. It may be prefixed by a downstream prefix
+ of the form __RFQDN_, or the experimental prefix ``x-``. If both
+ prefixes are present, the __RFDQN_ prefix goes first.
+
+ A valid name cannot start with ``q_``, which is reserved.
+
+ :param name: Name to check.
+ :param info: QAPI schema source file information.
+ :param source: Error string describing what ``name`` belongs to.
+
+ :raise QAPISemError: When ``name`` fails validation.
+ :return: The stem of the valid name, with no prefixes.
+ """
+ # Reserve the entire 'q_' namespace for c_name(), and for 'q_empty'
+ # and 'q_obj_*' implicit type names.
+ match = valid_name.match(name)
+ if not match or c_name(name, False).startswith('q_'):
+ raise QAPISemError(info, "%s has an invalid name" % source)
+ return match.group(3)
+
+
+def check_name_upper(name: str, info: QAPISourceInfo, source: str) -> None:
+ """
+ Ensure that ``name`` is a valid event name.
+
+ This means it must be a valid QAPI name as checked by
+ `check_name_str()`, but where the stem prohibits lowercase
+ characters and ``-``.
+
+ :param name: Name to check.
+ :param info: QAPI schema source file information.
+ :param source: Error string describing what ``name`` belongs to.
+
+ :raise QAPISemError: When ``name`` fails validation.
+ """
+ stem = check_name_str(name, info, source)
+ if re.search(r'[a-z-]', stem):
+ raise QAPISemError(
+ info, "name of %s must not use lowercase or '-'" % source)
+
+
+def check_name_lower(name: str, info: QAPISourceInfo, source: str,
+ permit_upper: bool = False,
+ permit_underscore: bool = False) -> None:
+ """
+ Ensure that ``name`` is a valid command or member name.
+
+ This means it must be a valid QAPI name as checked by
+ `check_name_str()`, but where the stem prohibits uppercase
+ characters and ``_``.
+
+ :param name: Name to check.
+ :param info: QAPI schema source file information.
+ :param source: Error string describing what ``name`` belongs to.
+ :param permit_upper: Additionally permit uppercase.
+ :param permit_underscore: Additionally permit ``_``.
+
+ :raise QAPISemError: When ``name`` fails validation.
+ """
+ stem = check_name_str(name, info, source)
+ if ((not permit_upper and re.search(r'[A-Z]', stem))
+ or (not permit_underscore and '_' in stem)):
+ raise QAPISemError(
+ info, "name of %s must not use uppercase or '_'" % source)
+
+
+def check_name_camel(name: str, info: QAPISourceInfo, source: str) -> None:
+ """
+ Ensure that ``name`` is a valid user-defined type name.
+
+ This means it must be a valid QAPI name as checked by
+ `check_name_str()`, but where the stem must be in CamelCase.
+
+ :param name: Name to check.
+ :param info: QAPI schema source file information.
+ :param source: Error string describing what ``name`` belongs to.
+
+ :raise QAPISemError: When ``name`` fails validation.
+ """
+ stem = check_name_str(name, info, source)
+ if not re.match(r'[A-Z][A-Za-z0-9]*[a-z][A-Za-z0-9]*$', stem):
+ raise QAPISemError(info, "name of %s must use CamelCase" % source)
+
+
+def check_defn_name_str(name: str, info: QAPISourceInfo, meta: str) -> None:
+ """
+ Ensure that ``name`` is a valid definition name.
+
+ Based on the value of ``meta``, this means that:
+ - 'event' names adhere to `check_name_upper()`.
+ - 'command' names adhere to `check_name_lower()`.
+ - Else, meta is a type, and must pass `check_name_camel()`.
+ These names must not end with ``List``.
+
+ :param name: Name to check.
+ :param info: QAPI schema source file information.
+ :param meta: Meta-type name of the QAPI expression.
+
+ :raise QAPISemError: When ``name`` fails validation.
+ """
+ if meta == 'event':
+ check_name_upper(name, info, meta)
+ elif meta == 'command':
+ check_name_lower(
+ name, info, meta,
+ permit_underscore=name in info.pragma.command_name_exceptions)
+ else:
+ check_name_camel(name, info, meta)
+ if name.endswith('List'):
+ raise QAPISemError(
+ info, "%s name should not end in 'List'" % meta)
+
+
+def check_keys(value: _JSONObject,
+ info: QAPISourceInfo,
+ source: str,
+ required: Collection[str],
+ optional: Collection[str]) -> None:
+ """
+ Ensure that a dict has a specific set of keys.
+
+ :param value: The dict to check.
+ :param info: QAPI schema source file information.
+ :param source: Error string describing this ``value``.
+ :param required: Keys that *must* be present.
+ :param optional: Keys that *may* be present.
+
+ :raise QAPISemError: When unknown keys are present.
+ """
+
+ def pprint(elems: Iterable[str]) -> str:
+ return ', '.join("'" + e + "'" for e in sorted(elems))
+
+ missing = set(required) - set(value)
+ if missing:
+ raise QAPISemError(
+ info,
+ "%s misses key%s %s"
+ % (source, 's' if len(missing) > 1 else '',
+ pprint(missing)))
+ allowed = set(required) | set(optional)
+ unknown = set(value) - allowed
+ if unknown:
+ raise QAPISemError(
+ info,
+ "%s has unknown key%s %s\nValid keys are %s."
+ % (source, 's' if len(unknown) > 1 else '',
+ pprint(unknown), pprint(allowed)))
+
+
+def check_flags(expr: _JSONObject, info: QAPISourceInfo) -> None:
+ """
+ Ensure flag members (if present) have valid values.
+
+ :param expr: The expression to validate.
+ :param info: QAPI schema source file information.
+
+ :raise QAPISemError:
+ When certain flags have an invalid value, or when
+ incompatible flags are present.
+ """
+ for key in ('gen', 'success-response'):
+ if key in expr and expr[key] is not False:
+ raise QAPISemError(
+ info, "flag '%s' may only use false value" % key)
+ for key in ('boxed', 'allow-oob', 'allow-preconfig', 'coroutine'):
+ if key in expr and expr[key] is not True:
+ raise QAPISemError(
+ info, "flag '%s' may only use true value" % key)
+ if 'allow-oob' in expr and 'coroutine' in expr:
+ # This is not necessarily a fundamental incompatibility, but
+ # we don't have a use case and the desired semantics isn't
+ # obvious. The simplest solution is to forbid it until we get
+ # a use case for it.
+ raise QAPISemError(info, "flags 'allow-oob' and 'coroutine' "
+ "are incompatible")
+
+
+def check_if(expr: _JSONObject, info: QAPISourceInfo, source: str) -> None:
+ """
+ Validate the ``if`` member of an object.
+
+ The ``if`` member may be either a ``str`` or a dict.
+
+ :param expr: The expression containing the ``if`` member to validate.
+ :param info: QAPI schema source file information.
+ :param source: Error string describing ``expr``.
+
+ :raise QAPISemError:
+ When the "if" member fails validation, or when there are no
+ non-empty conditions.
+ :return: None
+ """
+
+ def _check_if(cond: Union[str, object]) -> None:
+ if isinstance(cond, str):
+ if not re.fullmatch(r'[A-Z][A-Z0-9_]*', cond):
+ raise QAPISemError(
+ info,
+ "'if' condition '%s' of %s is not a valid identifier"
+ % (cond, source))
+ return
+
+ if not isinstance(cond, dict):
+ raise QAPISemError(
+ info,
+ "'if' condition of %s must be a string or an object" % source)
+ check_keys(cond, info, "'if' condition of %s" % source, [],
+ ["all", "any", "not"])
+ if len(cond) != 1:
+ raise QAPISemError(
+ info,
+ "'if' condition of %s has conflicting keys" % source)
+
+ if 'not' in cond:
+ _check_if(cond['not'])
+ elif 'all' in cond:
+ _check_infix('all', cond['all'])
+ else:
+ _check_infix('any', cond['any'])
+
+ def _check_infix(operator: str, operands: object) -> None:
+ if not isinstance(operands, list):
+ raise QAPISemError(
+ info,
+ "'%s' condition of %s must be an array"
+ % (operator, source))
+ if not operands:
+ raise QAPISemError(
+ info, "'if' condition [] of %s is useless" % source)
+ for operand in operands:
+ _check_if(operand)
+
+ ifcond = expr.get('if')
+ if ifcond is None:
+ return
+
+ _check_if(ifcond)
+
+
+def normalize_members(members: object) -> None:
+ """
+ Normalize a "members" value.
+
+ If ``members`` is a dict, for every value in that dict, if that
+ value is not itself already a dict, normalize it to
+ ``{'type': value}``.
+
+ :forms:
+ :sugared: ``Dict[str, Union[str, TypeRef]]``
+ :canonical: ``Dict[str, TypeRef]``
+
+ :param members: The members value to normalize.
+
+ :return: None, ``members`` is normalized in-place as needed.
+ """
+ if isinstance(members, dict):
+ for key, arg in members.items():
+ if isinstance(arg, dict):
+ continue
+ members[key] = {'type': arg}
+
+
+def check_type(value: Optional[object],
+ info: QAPISourceInfo,
+ source: str,
+ allow_array: bool = False,
+ allow_dict: Union[bool, str] = False) -> None:
+ """
+ Normalize and validate the QAPI type of ``value``.
+
+ Python types of ``str`` or ``None`` are always allowed.
+
+ :param value: The value to check.
+ :param info: QAPI schema source file information.
+ :param source: Error string describing this ``value``.
+ :param allow_array:
+ Allow a ``List[str]`` of length 1, which indicates an array of
+ the type named by the list element.
+ :param allow_dict:
+ Allow a dict. Its members can be struct type members or union
+ branches. When the value of ``allow_dict`` is in pragma
+ ``member-name-exceptions``, the dict's keys may violate the
+ member naming rules. The dict members are normalized in place.
+
+ :raise QAPISemError: When ``value`` fails validation.
+ :return: None, ``value`` is normalized in-place as needed.
+ """
+ if value is None:
+ return
+
+ # Type name
+ if isinstance(value, str):
+ return
+
+ # Array type
+ if isinstance(value, list):
+ if not allow_array:
+ raise QAPISemError(info, "%s cannot be an array" % source)
+ if len(value) != 1 or not isinstance(value[0], str):
+ raise QAPISemError(info,
+ "%s: array type must contain single type name" %
+ source)
+ return
+
+ # Anonymous type
+
+ if not allow_dict:
+ raise QAPISemError(info, "%s should be a type name" % source)
+
+ if not isinstance(value, dict):
+ raise QAPISemError(info,
+ "%s should be an object or type name" % source)
+
+ permissive = False
+ if isinstance(allow_dict, str):
+ permissive = allow_dict in info.pragma.member_name_exceptions
+
+ # value is a dictionary, check that each member is okay
+ for (key, arg) in value.items():
+ key_source = "%s member '%s'" % (source, key)
+ if key.startswith('*'):
+ key = key[1:]
+ check_name_lower(key, info, key_source,
+ permit_upper=permissive,
+ permit_underscore=permissive)
+ if c_name(key, False) == 'u' or c_name(key, False).startswith('has_'):
+ raise QAPISemError(info, "%s uses reserved name" % key_source)
+ check_keys(arg, info, key_source, ['type'], ['if', 'features'])
+ check_if(arg, info, key_source)
+ check_features(arg.get('features'), info)
+ check_type(arg['type'], info, key_source, allow_array=True)
+
+
+def check_features(features: Optional[object],
+ info: QAPISourceInfo) -> None:
+ """
+ Normalize and validate the ``features`` member.
+
+ ``features`` may be a ``list`` of either ``str`` or ``dict``.
+ Any ``str`` element will be normalized to ``{'name': element}``.
+
+ :forms:
+ :sugared: ``List[Union[str, Feature]]``
+ :canonical: ``List[Feature]``
+
+ :param features: The features member value to validate.
+ :param info: QAPI schema source file information.
+
+ :raise QAPISemError: When ``features`` fails validation.
+ :return: None, ``features`` is normalized in-place as needed.
+ """
+ if features is None:
+ return
+ if not isinstance(features, list):
+ raise QAPISemError(info, "'features' must be an array")
+ features[:] = [f if isinstance(f, dict) else {'name': f}
+ for f in features]
+ for feat in features:
+ source = "'features' member"
+ assert isinstance(feat, dict)
+ check_keys(feat, info, source, ['name'], ['if'])
+ check_name_is_str(feat['name'], info, source)
+ source = "%s '%s'" % (source, feat['name'])
+ check_name_str(feat['name'], info, source)
+ check_if(feat, info, source)
+
+
+def check_enum(expr: _JSONObject, info: QAPISourceInfo) -> None:
+ """
+ Normalize and validate this expression as an ``enum`` definition.
+
+ :param expr: The expression to validate.
+ :param info: QAPI schema source file information.
+
+ :raise QAPISemError: When ``expr`` is not a valid ``enum``.
+ :return: None, ``expr`` is normalized in-place as needed.
+ """
+ name = expr['enum']
+ members = expr['data']
+ prefix = expr.get('prefix')
+
+ if not isinstance(members, list):
+ raise QAPISemError(info, "'data' must be an array")
+ if prefix is not None and not isinstance(prefix, str):
+ raise QAPISemError(info, "'prefix' must be a string")
+
+ permissive = name in info.pragma.member_name_exceptions
+
+ members[:] = [m if isinstance(m, dict) else {'name': m}
+ for m in members]
+ for member in members:
+ source = "'data' member"
+ check_keys(member, info, source, ['name'], ['if', 'features'])
+ member_name = member['name']
+ check_name_is_str(member_name, info, source)
+ source = "%s '%s'" % (source, member_name)
+ # Enum members may start with a digit
+ if member_name[0].isdigit():
+ member_name = 'd' + member_name # Hack: hide the digit
+ check_name_lower(member_name, info, source,
+ permit_upper=permissive,
+ permit_underscore=permissive)
+ check_if(member, info, source)
+ check_features(member.get('features'), info)
+
+
+def check_struct(expr: _JSONObject, info: QAPISourceInfo) -> None:
+ """
+ Normalize and validate this expression as a ``struct`` definition.
+
+ :param expr: The expression to validate.
+ :param info: QAPI schema source file information.
+
+ :raise QAPISemError: When ``expr`` is not a valid ``struct``.
+ :return: None, ``expr`` is normalized in-place as needed.
+ """
+ name = cast(str, expr['struct']) # Checked in check_exprs
+ members = expr['data']
+
+ check_type(members, info, "'data'", allow_dict=name)
+ check_type(expr.get('base'), info, "'base'")
+
+
+def check_union(expr: _JSONObject, info: QAPISourceInfo) -> None:
+ """
+ Normalize and validate this expression as a ``union`` definition.
+
+ :param expr: The expression to validate.
+ :param info: QAPI schema source file information.
+
+ :raise QAPISemError: when ``expr`` is not a valid ``union``.
+ :return: None, ``expr`` is normalized in-place as needed.
+ """
+ name = cast(str, expr['union']) # Checked in check_exprs
+ base = expr['base']
+ discriminator = expr['discriminator']
+ members = expr['data']
+
+ check_type(base, info, "'base'", allow_dict=name)
+ check_name_is_str(discriminator, info, "'discriminator'")
+
+ if not isinstance(members, dict):
+ raise QAPISemError(info, "'data' must be an object")
+
+ for (key, value) in members.items():
+ source = "'data' member '%s'" % key
+ check_keys(value, info, source, ['type'], ['if'])
+ check_if(value, info, source)
+ check_type(value['type'], info, source, allow_array=not base)
+
+
+def check_alternate(expr: _JSONObject, info: QAPISourceInfo) -> None:
+ """
+ Normalize and validate this expression as an ``alternate`` definition.
+
+ :param expr: The expression to validate.
+ :param info: QAPI schema source file information.
+
+ :raise QAPISemError: When ``expr`` is not a valid ``alternate``.
+ :return: None, ``expr`` is normalized in-place as needed.
+ """
+ members = expr['data']
+
+ if not members:
+ raise QAPISemError(info, "'data' must not be empty")
+
+ if not isinstance(members, dict):
+ raise QAPISemError(info, "'data' must be an object")
+
+ for (key, value) in members.items():
+ source = "'data' member '%s'" % key
+ check_name_lower(key, info, source)
+ check_keys(value, info, source, ['type'], ['if'])
+ check_if(value, info, source)
+ check_type(value['type'], info, source)
+
+
+def check_command(expr: _JSONObject, info: QAPISourceInfo) -> None:
+ """
+ Normalize and validate this expression as a ``command`` definition.
+
+ :param expr: The expression to validate.
+ :param info: QAPI schema source file information.
+
+ :raise QAPISemError: When ``expr`` is not a valid ``command``.
+ :return: None, ``expr`` is normalized in-place as needed.
+ """
+ args = expr.get('data')
+ rets = expr.get('returns')
+ boxed = expr.get('boxed', False)
+
+ if boxed and args is None:
+ raise QAPISemError(info, "'boxed': true requires 'data'")
+ check_type(args, info, "'data'", allow_dict=not boxed)
+ check_type(rets, info, "'returns'", allow_array=True)
+
+
+def check_event(expr: _JSONObject, info: QAPISourceInfo) -> None:
+ """
+ Normalize and validate this expression as an ``event`` definition.
+
+ :param expr: The expression to validate.
+ :param info: QAPI schema source file information.
+
+ :raise QAPISemError: When ``expr`` is not a valid ``event``.
+ :return: None, ``expr`` is normalized in-place as needed.
+ """
+ args = expr.get('data')
+ boxed = expr.get('boxed', False)
+
+ if boxed and args is None:
+ raise QAPISemError(info, "'boxed': true requires 'data'")
+ check_type(args, info, "'data'", allow_dict=not boxed)
+
+
+def check_exprs(exprs: List[_JSONObject]) -> List[_JSONObject]:
+ """
+ Validate and normalize a list of parsed QAPI schema expressions.
+
+ This function accepts a list of expressions and metadata as returned
+ by the parser. It destructively normalizes the expressions in-place.
+
+ :param exprs: The list of expressions to normalize and validate.
+
+ :raise QAPISemError: When any expression fails validation.
+ :return: The same list of expressions (now modified).
+ """
+ for expr_elem in exprs:
+ # Expression
+ assert isinstance(expr_elem['expr'], dict)
+ for key in expr_elem['expr'].keys():
+ assert isinstance(key, str)
+ expr: _JSONObject = expr_elem['expr']
+
+ # QAPISourceInfo
+ assert isinstance(expr_elem['info'], QAPISourceInfo)
+ info: QAPISourceInfo = expr_elem['info']
+
+ # Optional[QAPIDoc]
+ tmp = expr_elem.get('doc')
+ assert tmp is None or isinstance(tmp, QAPIDoc)
+ doc: Optional[QAPIDoc] = tmp
+
+ if 'include' in expr:
+ continue
+
+ metas = expr.keys() & {'enum', 'struct', 'union', 'alternate',
+ 'command', 'event'}
+ if len(metas) != 1:
+ raise QAPISemError(
+ info,
+ "expression must have exactly one key"
+ " 'enum', 'struct', 'union', 'alternate',"
+ " 'command', 'event'")
+ meta = metas.pop()
+
+ check_name_is_str(expr[meta], info, "'%s'" % meta)
+ name = cast(str, expr[meta])
+ info.set_defn(meta, name)
+ check_defn_name_str(name, info, meta)
+
+ if doc:
+ if doc.symbol != name:
+ raise QAPISemError(
+ info, "documentation comment is for '%s'" % doc.symbol)
+ doc.check_expr(expr)
+ elif info.pragma.doc_required:
+ raise QAPISemError(info,
+ "documentation comment required")
+
+ if meta == 'enum':
+ check_keys(expr, info, meta,
+ ['enum', 'data'], ['if', 'features', 'prefix'])
+ check_enum(expr, info)
+ elif meta == 'union':
+ check_keys(expr, info, meta,
+ ['union', 'base', 'discriminator', 'data'],
+ ['if', 'features'])
+ normalize_members(expr.get('base'))
+ normalize_members(expr['data'])
+ check_union(expr, info)
+ elif meta == 'alternate':
+ check_keys(expr, info, meta,
+ ['alternate', 'data'], ['if', 'features'])
+ normalize_members(expr['data'])
+ check_alternate(expr, info)
+ elif meta == 'struct':
+ check_keys(expr, info, meta,
+ ['struct', 'data'], ['base', 'if', 'features'])
+ normalize_members(expr['data'])
+ check_struct(expr, info)
+ elif meta == 'command':
+ check_keys(expr, info, meta,
+ ['command'],
+ ['data', 'returns', 'boxed', 'if', 'features',
+ 'gen', 'success-response', 'allow-oob',
+ 'allow-preconfig', 'coroutine'])
+ normalize_members(expr.get('data'))
+ check_command(expr, info)
+ elif meta == 'event':
+ check_keys(expr, info, meta,
+ ['event'], ['data', 'boxed', 'if', 'features'])
+ normalize_members(expr.get('data'))
+ check_event(expr, info)
+ else:
+ assert False, 'unexpected meta type'
+
+ check_if(expr, info, meta)
+ check_features(expr.get('features'), info)
+ check_flags(expr, info)
+
+ return exprs