Signed-off-by: John Snow <jsnow@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.
+ """