From 7c6e446476ddcaa9c587c13f7815d14f8866ecea Mon Sep 17 00:00:00 2001 From: John Snow Date: Fri, 15 Mar 2024 16:22:55 +0100 Subject: [PATCH] qapi/parser: demote QAPIExpression to Dict[str, Any] MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Dict[str, object] is a stricter type, but with the way that code is currently arranged, it is infeasible to enforce this strictness. In particular, although expr.py's entire raison d'être is normalization and type-checking of QAPI Expressions, that type information is not "remembered" in any meaningful way by mypy because each individual expression is not downcast to a specific expression type that holds all the details of each expression's unique form. As a result, all of the code in schema.py that deals with actually creating type-safe specialized structures has no guarantee (myopically) that the data it is being passed is correct. There are two ways to solve this: (1) Re-assert that the incoming data is in the shape we expect it to be, or (2) Disable type checking for this data. (1) is appealing to my sense of strictness, but I gotta concede that it is asinine to re-check the shape of a QAPIExpression in schema.py when expr.py has just completed that work at length. The duplication of code and the nightmare thought of needing to update both locations if and when we change the shape of these structures makes me extremely reluctant to go down this route. (2) allows us the chance to miss updating types in the case that types are updated in expr.py, but it *is* an awful lot simpler and, importantly, gets us closer to type checking schema.py *at all*. Something is better than nothing, I'd argue. So, do the simpler dumber thing and worry about future strictness improvements later. Signed-off-by: John Snow Reviewed-by: Markus Armbruster Signed-off-by: Markus Armbruster Message-ID: <20240315152301.3621858-20-armbru@redhat.com> --- scripts/qapi/parser.py | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/scripts/qapi/parser.py b/scripts/qapi/parser.py index ec4ebef4e3..2f3c704fa2 100644 --- a/scripts/qapi/parser.py +++ b/scripts/qapi/parser.py @@ -19,6 +19,7 @@ import os import re from typing import ( TYPE_CHECKING, + Any, Dict, List, Mapping, @@ -43,7 +44,7 @@ if TYPE_CHECKING: _ExprValue = Union[List[object], Dict[str, object], str, bool] -class QAPIExpression(Dict[str, object]): +class QAPIExpression(Dict[str, Any]): # pylint: disable=too-few-public-methods def __init__(self, data: Mapping[str, object], -- 2.39.5