[PATCH v6 00/19] qapi: static typing conversion, pt2

[John Snow]

Hi, this series adds static type hints to the QAPI module.
This is part two, and covers introspect.py.

Part 2: https://gitlab.com/jsnow/qemu/-/tree/python-qapi-cleanup-pt2
Everything: https://gitlab.com/jsnow/qemu/-/tree/python-qapi-cleanup-pt6

- Requires Python 3.6+
- Requires mypy 0.770 or newer (for type analysis only)
- Requires pylint 2.6.0 or newer (for lint checking only)

(Note: pylint does not like Python 3.9 very much yet. Known problem.)

Type hints are added in patches that add *only* type hints and change no
other behavior. Any necessary changes to behavior to accommodate typing
are split out into their own tiny patches.

Every commit should pass with (from ./scripts):
 - flake8 qapi/
 - pylint --rcfile=qapi/pylintrc qapi/
 - mypy --config-file=qapi/mypy.ini qapi/
 - isort -c qapi/

V6:

001/19:[down] 'qapi: Replace List[str] with Sequence[str] for ifcond'
009/19:[0021] [FC] 'qapi/introspect.py: Introduce preliminary tree typing'
010/19:[0013] [FC] 'qapi/introspect.py: create a typed 'Annotated' data 
strutcure'
013/19:[down] 'qapi/introspect.py: remove _gen_variants helper'
014/19:[0053] [FC] 'qapi/introspect.py: add type hint annotations'
015/19:[down] 'qapi/introspect.py: Add docstrings to _gen_tree and 
_tree_to_qlit'
017/19:[down] 'qapi/introspect.py: Type _gen_tree variants as Sequence[str]'
018/19:[down] 'qapi/introspect.py: set _gen_tree's default ifcond argument to 
()'
019/19:[down] 'qapi/introspect.py: add SchemaMetaType enum'

01: New; consistently type ifcond as Seq[str] in already-typed files.
09: Adjust comment concerning _stub to be more clear (?)
    Rename _stub to _Stub, etc.
    TreeValue becomes JSONValue.
10: _NodeT becomes _ValueT to match the _Value name.
    Change visit_alternate_type whitespace around some more.
13: New, pre-requisite for using SchemaInfo aliases.
        (Was not appropriate to go into #14.)
14: Use Sequence[str] instead of List[str] for ifcond
    Use SchemaInfo "dummy types" instead of _DObject
15: Adjust comment to mention dict_value limitation.
    Add docstring for _gen_tree (from former "dummy types" patch).
    Change name of commit to reflect now-multiple docstring additions.

OPTIONAL PATCHES:

17: Use Sequence[QAPISchemaFeature] instead of Optional[List[QAPISchemaFeature]]
18: Set a default argument for ifcond to the empty tuple ().
    Stylistically matches the above patch.
19: Create a SchemaMetaType enum and use it instead of the string type.
    (Contains an optional blurb that can be removed if desired.)

V5:

04: Rename 'suppress_first_indent' to 'dict_value'
    (Docstring added in 014.)
06: Avoid changing the output structure of _make_tree
07: Chance the structure of _make_tree 8-)
08: Change commented TreeValue to include a TODO instead.
09: Change NodeT bound to _value instead of TreeValue
    Change "Remove in 3.7" text to include "TODO: "
    Remove forwarding suppress_first_indent/dict_value in recursive cases
    Change spacing in visit_alternate_type()
11: Consequence of suppress_first_value/dict_value change
12: Commit message note added
    Changed _DObject comment
13: Commit notes adjusted
    _DObject stuff: Comment near SchemaInfo et al adjusted
14: Changed docstring to reflect dict_value change
15: Updated copyright year for 2021 :~)

V4:
 - Rebased on "pt1.5" v4
 - signatures updated to use Optional[QAPISourceInfo]

John Snow (19):
  qapi: Replace List[str] with Sequence[str] for ifcond
  qapi/introspect.py: assert schema is not None
  qapi/introspect.py: use _make_tree for features nodes
  qapi/introspect.py: add _gen_features helper
  qapi/introspect.py: guard against ifcond/comment misuse
  qapi/introspect.py: Unify return type of _make_tree()
  qapi/introspect.py: replace 'extra' dict with 'comment' argument
  qapi/introspect.py: Always define all 'extra' dict keys
  qapi/introspect.py: Introduce preliminary tree typing
  qapi/introspect.py: create a typed 'Annotated' data strutcure
  qapi/introspect.py: improve _tree_to_qlit error message
  qapi/introspect.py: improve readability of _tree_to_qlit
  qapi/introspect.py: remove _gen_variants helper
  qapi/introspect.py: add type hint annotations
  qapi/introspect.py: Add docstrings to _gen_tree and _tree_to_qlit
  qapi/introspect.py: Update copyright and authors list
  qapi/introspect.py: Type _gen_tree variants as Sequence[str]
  qapi/introspect.py: set _gen_tree's default ifcond argument to ()
  qapi/introspect.py: add SchemaMetaType enum

 scripts/qapi/commands.py   |   3 +-
 scripts/qapi/events.py     |   4 +-
 scripts/qapi/gen.py        |  12 +-
 scripts/qapi/introspect.py | 350 +++++++++++++++++++++++++++----------
 scripts/qapi/mypy.ini      |   5 -
 scripts/qapi/schema.py     |   2 +-
 scripts/qapi/types.py      |  12 +-
 scripts/qapi/visit.py      |  10 +-
 8 files changed, 275 insertions(+), 123 deletions(-)

-- 
2.29.2