Signed-off-by: John Snow <js...@redhat.com> --- scripts/qapi/expr.py | 157 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 155 insertions(+), 2 deletions(-)
diff --git a/scripts/qapi/expr.py b/scripts/qapi/expr.py index f244e9648c..4bba09f6e5 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 +12,25 @@ # 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. + +After QAPI expressions are parsed from disk, they are stored in +recursively nested Python data structures using Dict, List, str, bool, +and int. This module ensures that those nested structures have the +correct type(s) and key(s) where appropriate for the QAPI context-free +grammar. + +The QAPI schema expression language also allows for 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 ( Iterable, @@ -46,6 +63,7 @@ def check_name_is_str(name: object, info: QAPISourceInfo, source: str) -> None: + """Ensures that `name` is a string. [Const]""" if not isinstance(name, str): raise QAPISemError(info, "%s requires a string name" % source) @@ -56,6 +74,24 @@ def check_name_str(name: str, allow_optional: bool = False, enum_member: bool = False, permit_upper: bool = False) -> None: + """ + Ensures a string is a legal name. [Const] + + A name is legal in the default case when: + - It matches ``(__[a-z0-9.-]+_)?[a-z][a-z0-9_-]*`` + - It does not start with ``q_`` or ``q-`` + + :param name: Name to check. + :param info: QAPI source file information. + :param source: Human-readable str describing "what" this name is. + :param allow_optional: Allow the very first character to be ``*``. + (Cannot be used with `enum_member`) + :param enum_member: Allow the very first character to be a digit. + (Cannot be used with `allow_optional`) + :param permit_upper: Allows upper-case characters wherever + lower-case characters are allowed. + """ + assert not (allow_optional and enum_member) membername = name if allow_optional and name.startswith('*'): @@ -76,6 +112,17 @@ def check_name_str(name: str, def check_defn_name_str(name: str, info: QAPISourceInfo, meta: str) -> None: + """ + Ensures a name is a legal definition name. [Const] + + A legal definition name: + - Adheres to the criteria in `check_name_str`, with uppercase permitted + - Does not end with ``Kind`` or ``List``. + + :param name: Name to check. + :param info: QAPI source file information. + :param meta: Type name of the QAPI expression. + """ check_name_str(name, info, meta, permit_upper=True) if name.endswith('Kind') or name.endswith('List'): raise QAPISemError( @@ -87,6 +134,15 @@ def check_keys(value: _JSObject, source: str, required: List[str], optional: List[str]) -> None: + """ + Ensures an object has a specific set of keys. [Const] + + :param value: The object to check. + :param info: QAPI source file information. + :param source: Human-readable str describing "what" this object is. + :param required: Keys that *must* be present. + :param optional: Keys that *may* be present. + """ def pprint(elems: Iterable[str]) -> str: return ', '.join("'" + e + "'" for e in sorted(elems)) @@ -109,6 +165,12 @@ def pprint(elems: Iterable[str]) -> str: def check_flags(expr: Expression, info: QAPISourceInfo) -> None: + """ + Ensures common fields in an Expression are correct. [Const] + + :param expr: Expression to validate. + :param info: QAPI source file information. + """ for key in ['gen', 'success-response']: if key in expr and expr[key] is not False: raise QAPISemError( @@ -120,6 +182,18 @@ def check_flags(expr: Expression, info: QAPISourceInfo) -> None: def check_if(expr: _JSObject, info: QAPISourceInfo, source: str) -> None: + """ + Syntactically validate and normalize the ``if`` field of an object. [RW] + + The ``if`` field may be either a `str` or a `List[str]`. + A `str` element will be normalized to `List[str]`. + + Sugared: `Union[str, List[str]]` + Ifcond: `List[str]` + + :param expr: A `dict`; the ``if`` field, if present, will be validated. + :param info: QAPI source file information. + """ def check_if_str(ifcond: object) -> None: if not isinstance(ifcond, str): @@ -148,6 +222,16 @@ def check_if_str(ifcond: object) -> None: def normalize_members(members: object) -> None: + """ + Normalize a "members" value. [RW] + + If `members` is an object, for every value in that object, if that + value is not itself already an object, normalize it to + ``{'type': value}``. + + Sugared: `Dict[str, Union[str, TypeRef]]` + Members: `Dict[str, TypeRef]` + """ if isinstance(members, dict): for key, arg in members.items(): if isinstance(arg, dict): @@ -160,6 +244,18 @@ def check_type(value: Optional[object], source: str, allow_array: bool = False, allow_dict: Union[bool, str] = False) -> None: + """ + Check the QAPI type of `value`. [RW] + + Python types of `str` or `None` are always allowed. + + :param value: The value to check. + :param info: QAPI Source file information. + :param source: Human readable string describing "what" the value is. + :param allow_array: Allow a `List[str]` of length 1, + which indicates an Array<T> type. + :param allow_dict: Allow a dict, treated as an anonymous type. + """ if value is None: return @@ -205,6 +301,15 @@ def check_type(value: Optional[object], def check_features(features: Optional[object], info: QAPISourceInfo) -> None: + """ + Syntactically validate and normalize the "features" field. [RW] + + `features` may be a List of either `str` or `dict`. + Any `str` element will be normalized to `{'name': element}`. + + Sugared: `List[Union[str, Feature]]` + Features: `List[Feature]` + """ if features is None: return if not isinstance(features, list): @@ -222,6 +327,12 @@ def check_features(features: Optional[object], def check_enum(expr: Expression, info: QAPISourceInfo) -> None: + """ + Validate this `Expression` as an ``enum`` expression. [RW] + + :param expr: `Expression` to validate. + :param info: QAPI source file information. + """ name = expr['enum'] members = expr['data'] prefix = expr.get('prefix') @@ -246,6 +357,12 @@ def check_enum(expr: Expression, info: QAPISourceInfo) -> None: def check_struct(expr: Expression, info: QAPISourceInfo) -> None: + """ + Validate this `Expression` as a ``struct`` expression. [RW] + + :param expr: `Expression` to validate. + :param info: QAPI source file information. + """ name = cast(str, expr['struct']) # Asserted in check_exprs members = expr['data'] @@ -254,6 +371,12 @@ def check_struct(expr: Expression, info: QAPISourceInfo) -> None: def check_union(expr: Expression, info: QAPISourceInfo) -> None: + """ + Validate this `Expression` as a ``union`` expression. [RW] + + :param expr: `Expression` to validate. + :param info: QAPI source file information. + """ name = cast(str, expr['union']) # Asserted in check_exprs base = expr.get('base') discriminator = expr.get('discriminator') @@ -280,6 +403,12 @@ def check_union(expr: Expression, info: QAPISourceInfo) -> None: def check_alternate(expr: Expression, info: QAPISourceInfo) -> None: + """ + Validate this `Expression` as an ``alternate`` expression. [RW] + + :param expr: Expression to validate. + :param info: QAPI source file information. + """ members = expr['data'] if not members: @@ -297,6 +426,12 @@ def check_alternate(expr: Expression, info: QAPISourceInfo) -> None: def check_command(expr: Expression, info: QAPISourceInfo) -> None: + """ + Validate this `Expression` as a ``command`` expression. [RW] + + :param expr: `Expression` to validate. + :param info: QAPI source file information. + """ args = expr.get('data') rets = expr.get('returns') boxed = expr.get('boxed', False) @@ -308,6 +443,16 @@ def check_command(expr: Expression, info: QAPISourceInfo) -> None: def check_event(expr: Expression, info: QAPISourceInfo) -> None: + """ + Normalize and syntactically validate the ``event`` expression. [RW] + + Event: + event: `str` + data: `Optional[Dict[str, Member]]` + boxed: `Optional[bool]` + if: `Optional[Ifcond]` + features: `Optional[Features]` + """ args = expr.get('data') boxed = expr.get('boxed', False) @@ -317,6 +462,14 @@ def check_event(expr: Expression, info: QAPISourceInfo) -> None: def check_exprs(exprs: List[_JSObject]) -> List[_JSObject]: + """ + Validate and normalize a list of parsed QAPI schema expressions. [RW] + + This function accepts a list of expressions + metadta as returned by + the parser. It destructively normalizes the expressions in-place. + + :param exprs: The list of expressions to normalize/validate. + """ for expr_elem in exprs: # Expression assert isinstance(expr_elem['expr'], dict) -- 2.26.2