diff options
Diffstat (limited to 'scripts/qapi/expr.py')
| -rw-r--r-- | scripts/qapi/expr.py | 256 |
1 files changed, 251 insertions, 5 deletions
diff --git a/scripts/qapi/expr.py b/scripts/qapi/expr.py index c33caf0..0b66d80 100644 --- a/scripts/qapi/expr.py +++ b/scripts/qapi/expr.py @@ -1,7 +1,5 @@ # -*- coding: utf-8 -*- # -# Check (context-free) QAPI schema expression structure -# # Copyright IBM, Corp. 2011 # Copyright (c) 2013-2019 Red Hat Inc. # @@ -14,6 +12,24 @@ # 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, @@ -39,9 +55,7 @@ from .source import QAPISourceInfo _JSONObject = Dict[str, object] -# Names consist of letters, digits, -, and _, starting with a letter. -# An experimental name is prefixed with x-. A name of a downstream -# extension is prefixed with __RFQDN_. The latter prefix goes first. +# See check_name_str(), below. valid_name = re.compile(r'(__[a-z0-9.-]+_)?' r'(x-)?' r'([a-z][a-z0-9_-]*)$', re.IGNORECASE) @@ -50,11 +64,33 @@ valid_name = re.compile(r'(__[a-z0-9.-]+_)?' 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) @@ -64,6 +100,19 @@ def check_name_str(name: str, info: QAPISourceInfo, source: str) -> str: 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( @@ -73,6 +122,21 @@ def check_name_upper(name: str, info: QAPISourceInfo, source: str) -> None: 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)): @@ -81,12 +145,39 @@ def check_name_lower(name: str, info: QAPISourceInfo, source: str, 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 ``Kind`` nor ``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': @@ -105,6 +196,17 @@ def check_keys(value: _JSONObject, 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)) @@ -127,6 +229,16 @@ def check_keys(value: _JSONObject, 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( @@ -145,7 +257,25 @@ def check_flags(expr: _JSONObject, info: QAPISourceInfo) -> None: def check_if(expr: _JSONObject, info: QAPISourceInfo, source: str) -> None: + """ + Normalize and validate the ``if`` member of an object. + The ``if`` member may be either a ``str`` or a ``List[str]``. + A ``str`` value will be normalized to ``List[str]``. + + :forms: + :sugared: ``Union[str, List[str]]`` + :canonical: ``List[str]`` + + :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, ``expr`` is normalized in-place as needed. + """ ifcond = expr.get('if') if ifcond is None: return @@ -172,6 +302,21 @@ def check_if(expr: _JSONObject, info: QAPISourceInfo, source: str) -> None: 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): @@ -184,6 +329,26 @@ def check_type(value: Optional[object], 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 @@ -232,6 +397,22 @@ def check_type(value: Optional[object], 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): @@ -249,6 +430,15 @@ def check_features(features: Optional[object], 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') @@ -278,6 +468,15 @@ def check_enum(expr: _JSONObject, info: QAPISourceInfo) -> None: 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'] @@ -286,6 +485,15 @@ def check_struct(expr: _JSONObject, info: QAPISourceInfo) -> None: 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.get('base') discriminator = expr.get('discriminator') @@ -314,6 +522,15 @@ def check_union(expr: _JSONObject, info: QAPISourceInfo) -> None: 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: @@ -331,6 +548,15 @@ def check_alternate(expr: _JSONObject, info: QAPISourceInfo) -> None: 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) @@ -342,6 +568,15 @@ def check_command(expr: _JSONObject, info: QAPISourceInfo) -> None: 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) @@ -351,6 +586,17 @@ def check_event(expr: _JSONObject, info: QAPISourceInfo) -> None: 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) |