[PULL 0/8] QAPI patches patches for 2023-02-23

[PULL 0/8] QAPI patches patches for 2023-02-23

[Markus Armbruster]

The following changes since commit 79b677d658d3d35e1e776826ac4abb28cdce69b8:

  Merge tag 'net-pull-request' of https://github.com/jasowang/qemu into staging (2023-02-21 11:28:31 +0000)

are available in the Git repository at:

  https://repo.or.cz/qemu/armbru.git tags/pull-qapi-2023-02-23

for you to fetch changes up to c7b7a7ded9376ad936cfedd843752789ca61bc3b:

  qapi: remove JSON value FIXME (2023-02-23 13:01:45 +0100)

----------------------------------------------------------------
QAPI patches patches for 2023-02-23

----------------------------------------------------------------
John Snow (6):
      qapi: Update flake8 config
      qapi: update pylint configuration
      qapi: Add minor typing workaround for 3.6
      qapi/parser: add QAPIExpression type
      qapi: remove _JSONObject
      qapi: remove JSON value FIXME

Markus Armbruster (2):
      docs/devel/qapi-code-gen: Belatedly update features documentation
      docs/devel/qapi-code-gen: Fix a missing 'may', clarify SchemaInfo

 docs/devel/qapi-code-gen.rst |  16 +++----
 scripts/qapi/.flake8         |   3 +-
 scripts/qapi/expr.py         | 100 ++++++++++++++++---------------------------
 scripts/qapi/parser.py       |  41 ++++++++++--------
 scripts/qapi/pylintrc        |   1 +
 scripts/qapi/schema.py       |  72 +++++++++++++++++--------------
 6 files changed, 111 insertions(+), 122 deletions(-)

-- 
2.39.0

[PULL 1/8] docs/devel/qapi-code-gen: Belatedly update features documentation

[Markus Armbruster]

Commit 013b4efc9be "qapi: Add feature flags to remaining
definitions" (v5.0.0), commit 84ab0086879 "qapi: Add feature flags to
struct members" (v5.0.0), and commit b6c18755e41 "qapi: Add feature
flags to enum members" (v6.2.0) neglected to update section
"Features".  Make up for that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20230213132009.918801-2-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
---
 docs/devel/qapi-code-gen.rst | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/docs/devel/qapi-code-gen.rst b/docs/devel/qapi-code-gen.rst
index 5edc49aa74..566640edf8 100644
--- a/docs/devel/qapi-code-gen.rst
+++ b/docs/devel/qapi-code-gen.rst
@@ -685,9 +685,10 @@ change in the QMP syntax (usually by allowing values or operations
 that previously resulted in an error).  QMP clients may still need to
 know whether the extension is available.
 
-For this purpose, a list of features can be specified for a command or
-struct type.  Each list member can either be ``{ 'name': STRING, '*if':
-COND }``, or STRING, which is shorthand for ``{ 'name': STRING }``.
+For this purpose, a list of features can be specified for definitions,
+enumeration values, and struct members.  Each feature list member can
+either be ``{ 'name': STRING, '*if': COND }``, or STRING, which is
+shorthand for ``{ 'name': STRING }``.
 
 The optional 'if' member specifies a conditional.  See `Configuring
 the schema`_ below for more on this.
-- 
2.39.0

[PULL 2/8] docs/devel/qapi-code-gen: Fix a missing 'may', clarify SchemaInfo

[Markus Armbruster]

Documentation of enumeration value conditions lacks a 'may'.  Fix
that.

Clarify SchemaInfo documentation for struct and union types.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20230213132009.918801-3-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
---
 docs/devel/qapi-code-gen.rst | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/docs/devel/qapi-code-gen.rst b/docs/devel/qapi-code-gen.rst
index 566640edf8..23e7f2fb1c 100644
--- a/docs/devel/qapi-code-gen.rst
+++ b/docs/devel/qapi-code-gen.rst
@@ -818,8 +818,8 @@ member 'bar' ::
 
 A union's discriminator may not be conditional.
 
-Likewise, individual enumeration values be conditional.  This requires
-the longhand form of ENUM-VALUE_.
+Likewise, individual enumeration values may be conditional.  This
+requires the longhand form of ENUM-VALUE_.
 
 Example: an enum type with unconditional value 'foo' and conditional
 value 'bar' ::
@@ -1158,9 +1158,8 @@ Example: the SchemaInfo for EVENT_C from section Events_ ::
     Type "q_obj-EVENT_C-arg" is an implicitly defined object type with
     the two members from the event's definition.
 
-The SchemaInfo for struct and union types has meta-type "object".
-
-The SchemaInfo for a struct type has variant member "members".
+The SchemaInfo for struct and union types has meta-type "object" and
+variant member "members".
 
 The SchemaInfo for a union type additionally has variant members "tag"
 and "variants".
-- 
2.39.0

[PULL 3/8] qapi: Update flake8 config

[Markus Armbruster]

From: John Snow <jsnow@redhat.com>

New versions of flake8 don't like same-line comments. (It's a version
newer than what fc37 ships, but it still makes my life easier to fix it
now.)

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20230215000011.1725012-2-jsnow@redhat.com>
---
 scripts/qapi/.flake8 | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/scripts/qapi/.flake8 b/scripts/qapi/.flake8
index 6b158c68b8..a873ff6730 100644
--- a/scripts/qapi/.flake8
+++ b/scripts/qapi/.flake8
@@ -1,2 +1,3 @@
 [flake8]
-extend-ignore = E722  # Prefer pylint's bare-except checks to flake8's
+# Prefer pylint's bare-except checks to flake8's
+extend-ignore = E722
-- 
2.39.0

[PULL 4/8] qapi: update pylint configuration

[Markus Armbruster]

From: John Snow <jsnow@redhat.com>

Newer versions of pylint disable the "no-self-use" message by
default. Older versions don't, though. If we leave the suppressions in,
pylint yelps about useless options. Just tell pylint to shush.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20230215000011.1725012-3-jsnow@redhat.com>
---
 scripts/qapi/pylintrc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/scripts/qapi/pylintrc b/scripts/qapi/pylintrc
index a724628203..90546df534 100644
--- a/scripts/qapi/pylintrc
+++ b/scripts/qapi/pylintrc
@@ -23,6 +23,7 @@ disable=fixme,
         too-many-statements,
         too-many-instance-attributes,
         consider-using-f-string,
+        useless-option-value,
 
 [REPORTS]
 
-- 
2.39.0

[PULL 5/8] qapi: Add minor typing workaround for 3.6

[Markus Armbruster]

From: John Snow <jsnow@redhat.com>

Pylint under 3.6 does not believe that Collection is subscriptable at
runtime. It is, making this a Pylint
bug. https://github.com/PyCQA/pylint/issues/2377

They closed it as fixed, but that doesn't seem to be true as of Pylint
2.13.9, the latest version you can install under Python 3.6. 2.13.9 was
released 2022-05-13, about seven months after the bug was closed.

The least-annoying fix here is to just use the concret type.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20230215000011.1725012-4-jsnow@redhat.com>
[Dumbed down from Sequence[str] to List[str], commit message adjusted]
Reviewed-by: Markus Armbruster <armbru@redhat.com>
---
 scripts/qapi/expr.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/scripts/qapi/expr.py b/scripts/qapi/expr.py
index 5a1782b57e..358b8e2a8b 100644
--- a/scripts/qapi/expr.py
+++ b/scripts/qapi/expr.py
@@ -33,7 +33,6 @@
 
 import re
 from typing import (
-    Collection,
     Dict,
     Iterable,
     List,
@@ -195,8 +194,8 @@ def check_defn_name_str(name: str, info: QAPISourceInfo, meta: str) -> None:
 def check_keys(value: _JSONObject,
                info: QAPISourceInfo,
                source: str,
-               required: Collection[str],
-               optional: Collection[str]) -> None:
+               required: List[str],
+               optional: List[str]) -> None:
     """
     Ensure that a dict has a specific set of keys.
 
-- 
2.39.0

[PULL 6/8] qapi/parser: add QAPIExpression type

[Markus Armbruster]

From: John Snow <jsnow@redhat.com>

This patch creates a new type, QAPIExpression, which represents a parsed
expression complete with QAPIDoc and QAPISourceInfo.

This patch turns parser.exprs into a list of QAPIExpression instead,
and adjusts expr.py to match.

This allows the types we specify in parser.py to be "remembered" all the
way through expr.py and into schema.py. Several assertions around
packing and unpacking this data can be removed as a result.

It also corrects a harmless typing error.  Before the patch,
check_exprs() allegedly takes a List[_JSONObject].  It actually takes
a list of dicts of the form

    {'expr': E, 'info': I, 'doc': D}

where E is of type _ExprValue, I is of type QAPISourceInfo, and D is
of type QAPIDoc.  Key 'doc' is optional.  This is not a _JSONObject!
Passes type checking anyway, because _JSONObject is Dict[str, object].

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20230215000011.1725012-5-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message amended to point out the typing fix]
---
 scripts/qapi/expr.py   | 82 +++++++++++++++++-------------------------
 scripts/qapi/parser.py | 46 ++++++++++++++----------
 scripts/qapi/schema.py | 72 ++++++++++++++++++++-----------------
 3 files changed, 100 insertions(+), 100 deletions(-)

diff --git a/scripts/qapi/expr.py b/scripts/qapi/expr.py
index 358b8e2a8b..b8f905543e 100644
--- a/scripts/qapi/expr.py
+++ b/scripts/qapi/expr.py
@@ -43,7 +43,7 @@
 
 from .common import c_name
 from .error import QAPISemError
-from .parser import QAPIDoc
+from .parser import QAPIExpression
 from .source import QAPISourceInfo
 
 
@@ -228,12 +228,11 @@ def pprint(elems: Iterable[str]) -> str:
                pprint(unknown), pprint(allowed)))
 
 
-def check_flags(expr: _JSONObject, info: QAPISourceInfo) -> None:
+def check_flags(expr: QAPIExpression) -> 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
@@ -242,18 +241,18 @@ def check_flags(expr: _JSONObject, info: QAPISourceInfo) -> None:
     for key in ('gen', 'success-response'):
         if key in expr and expr[key] is not False:
             raise QAPISemError(
-                info, "flag '%s' may only use false value" % key)
+                expr.info, "flag '%s' may only use false value" % key)
     for key in ('boxed', 'allow-oob', 'allow-preconfig', 'coroutine'):
         if key in expr and expr[key] is not True:
             raise QAPISemError(
-                info, "flag '%s' may only use true value" % key)
+                expr.info, "flag '%s' may only use true value" % key)
     if 'allow-oob' in expr and 'coroutine' in expr:
         # This is not necessarily a fundamental incompatibility, but
         # we don't have a use case and the desired semantics isn't
         # obvious.  The simplest solution is to forbid it until we get
         # a use case for it.
-        raise QAPISemError(info, "flags 'allow-oob' and 'coroutine' "
-                                 "are incompatible")
+        raise QAPISemError(
+            expr.info, "flags 'allow-oob' and 'coroutine' are incompatible")
 
 
 def check_if(expr: _JSONObject, info: QAPISourceInfo, source: str) -> None:
@@ -446,12 +445,11 @@ def check_features(features: Optional[object],
         check_if(feat, info, source)
 
 
-def check_enum(expr: _JSONObject, info: QAPISourceInfo) -> None:
+def check_enum(expr: QAPIExpression) -> 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.
@@ -459,6 +457,7 @@ def check_enum(expr: _JSONObject, info: QAPISourceInfo) -> None:
     name = expr['enum']
     members = expr['data']
     prefix = expr.get('prefix')
+    info = expr.info
 
     if not isinstance(members, list):
         raise QAPISemError(info, "'data' must be an array")
@@ -485,12 +484,11 @@ def check_enum(expr: _JSONObject, info: QAPISourceInfo) -> None:
         check_features(member.get('features'), info)
 
 
-def check_struct(expr: _JSONObject, info: QAPISourceInfo) -> None:
+def check_struct(expr: QAPIExpression) -> 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.
@@ -498,16 +496,15 @@ def check_struct(expr: _JSONObject, info: QAPISourceInfo) -> None:
     name = cast(str, expr['struct'])  # Checked in check_exprs
     members = expr['data']
 
-    check_type(members, info, "'data'", allow_dict=name)
-    check_type(expr.get('base'), info, "'base'")
+    check_type(members, expr.info, "'data'", allow_dict=name)
+    check_type(expr.get('base'), expr.info, "'base'")
 
 
-def check_union(expr: _JSONObject, info: QAPISourceInfo) -> None:
+def check_union(expr: QAPIExpression) -> 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.
@@ -516,6 +513,7 @@ def check_union(expr: _JSONObject, info: QAPISourceInfo) -> None:
     base = expr['base']
     discriminator = expr['discriminator']
     members = expr['data']
+    info = expr.info
 
     check_type(base, info, "'base'", allow_dict=name)
     check_name_is_str(discriminator, info, "'discriminator'")
@@ -530,17 +528,17 @@ def check_union(expr: _JSONObject, info: QAPISourceInfo) -> None:
         check_type(value['type'], info, source, allow_array=not base)
 
 
-def check_alternate(expr: _JSONObject, info: QAPISourceInfo) -> None:
+def check_alternate(expr: QAPIExpression) -> 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']
+    info = expr.info
 
     if not members:
         raise QAPISemError(info, "'data' must not be empty")
@@ -556,12 +554,11 @@ def check_alternate(expr: _JSONObject, info: QAPISourceInfo) -> None:
         check_type(value['type'], info, source, allow_array=True)
 
 
-def check_command(expr: _JSONObject, info: QAPISourceInfo) -> None:
+def check_command(expr: QAPIExpression) -> 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.
@@ -571,17 +568,16 @@ def check_command(expr: _JSONObject, info: QAPISourceInfo) -> None:
     boxed = expr.get('boxed', False)
 
     if boxed and args is None:
-        raise QAPISemError(info, "'boxed': true requires 'data'")
-    check_type(args, info, "'data'", allow_dict=not boxed)
-    check_type(rets, info, "'returns'", allow_array=True)
+        raise QAPISemError(expr.info, "'boxed': true requires 'data'")
+    check_type(args, expr.info, "'data'", allow_dict=not boxed)
+    check_type(rets, expr.info, "'returns'", allow_array=True)
 
 
-def check_event(expr: _JSONObject, info: QAPISourceInfo) -> None:
+def check_event(expr: QAPIExpression) -> 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.
@@ -590,11 +586,11 @@ def check_event(expr: _JSONObject, info: QAPISourceInfo) -> None:
     boxed = expr.get('boxed', False)
 
     if boxed and args is None:
-        raise QAPISemError(info, "'boxed': true requires 'data'")
-    check_type(args, info, "'data'", allow_dict=not boxed)
+        raise QAPISemError(expr.info, "'boxed': true requires 'data'")
+    check_type(args, expr.info, "'data'", allow_dict=not boxed)
 
 
-def check_exprs(exprs: List[_JSONObject]) -> List[_JSONObject]:
+def check_exprs(exprs: List[QAPIExpression]) -> List[QAPIExpression]:
     """
     Validate and normalize a list of parsed QAPI schema expressions.
 
@@ -606,21 +602,9 @@ def check_exprs(exprs: List[_JSONObject]) -> List[_JSONObject]:
     :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)
-        for key in expr_elem['expr'].keys():
-            assert isinstance(key, str)
-        expr: _JSONObject = expr_elem['expr']
-
-        # QAPISourceInfo
-        assert isinstance(expr_elem['info'], QAPISourceInfo)
-        info: QAPISourceInfo = expr_elem['info']
-
-        # Optional[QAPIDoc]
-        tmp = expr_elem.get('doc')
-        assert tmp is None or isinstance(tmp, QAPIDoc)
-        doc: Optional[QAPIDoc] = tmp
+    for expr in exprs:
+        info = expr.info
+        doc = expr.doc
 
         if 'include' in expr:
             continue
@@ -652,24 +636,24 @@ def check_exprs(exprs: List[_JSONObject]) -> List[_JSONObject]:
         if meta == 'enum':
             check_keys(expr, info, meta,
                        ['enum', 'data'], ['if', 'features', 'prefix'])
-            check_enum(expr, info)
+            check_enum(expr)
         elif meta == 'union':
             check_keys(expr, info, meta,
                        ['union', 'base', 'discriminator', 'data'],
                        ['if', 'features'])
             normalize_members(expr.get('base'))
             normalize_members(expr['data'])
-            check_union(expr, info)
+            check_union(expr)
         elif meta == 'alternate':
             check_keys(expr, info, meta,
                        ['alternate', 'data'], ['if', 'features'])
             normalize_members(expr['data'])
-            check_alternate(expr, info)
+            check_alternate(expr)
         elif meta == 'struct':
             check_keys(expr, info, meta,
                        ['struct', 'data'], ['base', 'if', 'features'])
             normalize_members(expr['data'])
-            check_struct(expr, info)
+            check_struct(expr)
         elif meta == 'command':
             check_keys(expr, info, meta,
                        ['command'],
@@ -677,17 +661,17 @@ def check_exprs(exprs: List[_JSONObject]) -> List[_JSONObject]:
                         'gen', 'success-response', 'allow-oob',
                         'allow-preconfig', 'coroutine'])
             normalize_members(expr.get('data'))
-            check_command(expr, info)
+            check_command(expr)
         elif meta == 'event':
             check_keys(expr, info, meta,
                        ['event'], ['data', 'boxed', 'if', 'features'])
             normalize_members(expr.get('data'))
-            check_event(expr, info)
+            check_event(expr)
         else:
             assert False, 'unexpected meta type'
 
         check_if(expr, info, meta)
         check_features(expr.get('features'), info)
-        check_flags(expr, info)
+        check_flags(expr)
 
     return exprs
diff --git a/scripts/qapi/parser.py b/scripts/qapi/parser.py
index 1b006cdc13..50906e27d4 100644
--- a/scripts/qapi/parser.py
+++ b/scripts/qapi/parser.py
@@ -21,6 +21,7 @@
     TYPE_CHECKING,
     Dict,
     List,
+    Mapping,
     Optional,
     Set,
     Union,
@@ -37,15 +38,24 @@
     from .schema import QAPISchemaFeature, QAPISchemaMember
 
 
-#: Represents a single Top Level QAPI schema expression.
-TopLevelExpr = Dict[str, object]
-
 # Return value alias for get_expr().
 _ExprValue = Union[List[object], Dict[str, object], str, bool]
 
-# FIXME: Consolidate and centralize definitions for TopLevelExpr,
-# _ExprValue, _JSONValue, and _JSONObject; currently scattered across
-# several modules.
+
+# FIXME: Consolidate and centralize definitions for _ExprValue,
+# JSONValue, and _JSONObject; currently scattered across several
+# modules.
+
+
+class QAPIExpression(Dict[str, object]):
+    # pylint: disable=too-few-public-methods
+    def __init__(self,
+                 data: Mapping[str, object],
+                 info: QAPISourceInfo,
+                 doc: Optional['QAPIDoc'] = None):
+        super().__init__(data)
+        self.info = info
+        self.doc: Optional['QAPIDoc'] = doc
 
 
 class QAPIParseError(QAPISourceError):
@@ -100,7 +110,7 @@ def __init__(self,
         self.line_pos = 0
 
         # Parser output:
-        self.exprs: List[Dict[str, object]] = []
+        self.exprs: List[QAPIExpression] = []
         self.docs: List[QAPIDoc] = []
 
         # Showtime!
@@ -147,8 +157,7 @@ def _parse(self) -> None:
                                        "value of 'include' must be a string")
                 incl_fname = os.path.join(os.path.dirname(self._fname),
                                           include)
-                self.exprs.append({'expr': {'include': incl_fname},
-                                   'info': info})
+                self._add_expr(OrderedDict({'include': incl_fname}), info)
                 exprs_include = self._include(include, info, incl_fname,
                                               self._included)
                 if exprs_include:
@@ -165,17 +174,18 @@ def _parse(self) -> None:
                 for name, value in pragma.items():
                     self._pragma(name, value, info)
             else:
-                expr_elem = {'expr': expr,
-                             'info': info}
-                if cur_doc:
-                    if not cur_doc.symbol:
-                        raise QAPISemError(
-                            cur_doc.info, "definition documentation required")
-                    expr_elem['doc'] = cur_doc
-                self.exprs.append(expr_elem)
+                if cur_doc and not cur_doc.symbol:
+                    raise QAPISemError(
+                        cur_doc.info, "definition documentation required")
+                self._add_expr(expr, info, cur_doc)
             cur_doc = None
         self.reject_expr_doc(cur_doc)
 
+    def _add_expr(self, expr: Mapping[str, object],
+                  info: QAPISourceInfo,
+                  doc: Optional['QAPIDoc'] = None) -> None:
+        self.exprs.append(QAPIExpression(expr, info, doc))
+
     @staticmethod
     def reject_expr_doc(doc: Optional['QAPIDoc']) -> None:
         if doc and doc.symbol:
@@ -784,7 +794,7 @@ def connect_feature(self, feature: 'QAPISchemaFeature') -> None:
                                % feature.name)
         self.features[feature.name].connect(feature)
 
-    def check_expr(self, expr: TopLevelExpr) -> None:
+    def check_expr(self, expr: QAPIExpression) -> None:
         if self.has_section('Returns') and 'command' not in expr:
             raise QAPISemError(self.info,
                                "'Returns:' is only valid for commands")
diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py
index cd8661125c..207e4d71f3 100644
--- a/scripts/qapi/schema.py
+++ b/scripts/qapi/schema.py
@@ -17,7 +17,7 @@
 from collections import OrderedDict
 import os
 import re
-from typing import Optional
+from typing import List, Optional
 
 from .common import (
     POINTER_SUFFIX,
@@ -29,7 +29,7 @@
 )
 from .error import QAPIError, QAPISemError, QAPISourceError
 from .expr import check_exprs
-from .parser import QAPISchemaParser
+from .parser import QAPIExpression, QAPISchemaParser
 
 
 class QAPISchemaIfCond:
@@ -964,10 +964,11 @@ def module_by_fname(self, fname):
         name = self._module_name(fname)
         return self._module_dict[name]
 
-    def _def_include(self, expr, info, doc):
+    def _def_include(self, expr: QAPIExpression):
         include = expr['include']
-        assert doc is None
-        self._def_entity(QAPISchemaInclude(self._make_module(include), info))
+        assert expr.doc is None
+        self._def_entity(
+            QAPISchemaInclude(self._make_module(include), expr.info))
 
     def _def_builtin_type(self, name, json_type, c_type):
         self._def_entity(QAPISchemaBuiltinType(name, json_type, c_type))
@@ -1045,14 +1046,15 @@ def _make_implicit_object_type(self, name, info, ifcond, role, members):
                 name, info, None, ifcond, None, None, members, None))
         return name
 
-    def _def_enum_type(self, expr, info, doc):
+    def _def_enum_type(self, expr: QAPIExpression):
         name = expr['enum']
         data = expr['data']
         prefix = expr.get('prefix')
         ifcond = QAPISchemaIfCond(expr.get('if'))
+        info = expr.info
         features = self._make_features(expr.get('features'), info)
         self._def_entity(QAPISchemaEnumType(
-            name, info, doc, ifcond, features,
+            name, info, expr.doc, ifcond, features,
             self._make_enum_members(data, info), prefix))
 
     def _make_member(self, name, typ, ifcond, features, info):
@@ -1072,14 +1074,15 @@ def _make_members(self, data, info):
                                   value.get('features'), info)
                 for (key, value) in data.items()]
 
-    def _def_struct_type(self, expr, info, doc):
+    def _def_struct_type(self, expr: QAPIExpression):
         name = expr['struct']
         base = expr.get('base')
         data = expr['data']
+        info = expr.info
         ifcond = QAPISchemaIfCond(expr.get('if'))
         features = self._make_features(expr.get('features'), info)
         self._def_entity(QAPISchemaObjectType(
-            name, info, doc, ifcond, features, base,
+            name, info, expr.doc, ifcond, features, base,
             self._make_members(data, info),
             None))
 
@@ -1089,11 +1092,13 @@ def _make_variant(self, case, typ, ifcond, info):
             typ = self._make_array_type(typ[0], info)
         return QAPISchemaVariant(case, info, typ, ifcond)
 
-    def _def_union_type(self, expr, info, doc):
+    def _def_union_type(self, expr: QAPIExpression):
         name = expr['union']
         base = expr['base']
         tag_name = expr['discriminator']
         data = expr['data']
+        assert isinstance(data, dict)
+        info = expr.info
         ifcond = QAPISchemaIfCond(expr.get('if'))
         features = self._make_features(expr.get('features'), info)
         if isinstance(base, dict):
@@ -1105,17 +1110,19 @@ def _def_union_type(self, expr, info, doc):
                                QAPISchemaIfCond(value.get('if')),
                                info)
             for (key, value) in data.items()]
-        members = []
+        members: List[QAPISchemaObjectTypeMember] = []
         self._def_entity(
-            QAPISchemaObjectType(name, info, doc, ifcond, features,
+            QAPISchemaObjectType(name, info, expr.doc, ifcond, features,
                                  base, members,
                                  QAPISchemaVariants(
                                      tag_name, info, None, variants)))
 
-    def _def_alternate_type(self, expr, info, doc):
+    def _def_alternate_type(self, expr: QAPIExpression):
         name = expr['alternate']
         data = expr['data']
+        assert isinstance(data, dict)
         ifcond = QAPISchemaIfCond(expr.get('if'))
+        info = expr.info
         features = self._make_features(expr.get('features'), info)
         variants = [
             self._make_variant(key, value['type'],
@@ -1124,11 +1131,11 @@ def _def_alternate_type(self, expr, info, doc):
             for (key, value) in data.items()]
         tag_member = QAPISchemaObjectTypeMember('type', info, 'QType', False)
         self._def_entity(
-            QAPISchemaAlternateType(name, info, doc, ifcond, features,
-                                    QAPISchemaVariants(
-                                        None, info, tag_member, variants)))
+            QAPISchemaAlternateType(
+                name, info, expr.doc, ifcond, features,
+                QAPISchemaVariants(None, info, tag_member, variants)))
 
-    def _def_command(self, expr, info, doc):
+    def _def_command(self, expr: QAPIExpression):
         name = expr['command']
         data = expr.get('data')
         rets = expr.get('returns')
@@ -1139,6 +1146,7 @@ def _def_command(self, expr, info, doc):
         allow_preconfig = expr.get('allow-preconfig', False)
         coroutine = expr.get('coroutine', False)
         ifcond = QAPISchemaIfCond(expr.get('if'))
+        info = expr.info
         features = self._make_features(expr.get('features'), info)
         if isinstance(data, OrderedDict):
             data = self._make_implicit_object_type(
@@ -1147,44 +1155,42 @@ def _def_command(self, expr, info, doc):
         if isinstance(rets, list):
             assert len(rets) == 1
             rets = self._make_array_type(rets[0], info)
-        self._def_entity(QAPISchemaCommand(name, info, doc, ifcond, features,
-                                           data, rets,
+        self._def_entity(QAPISchemaCommand(name, info, expr.doc, ifcond,
+                                           features, data, rets,
                                            gen, success_response,
                                            boxed, allow_oob, allow_preconfig,
                                            coroutine))
 
-    def _def_event(self, expr, info, doc):
+    def _def_event(self, expr: QAPIExpression):
         name = expr['event']
         data = expr.get('data')
         boxed = expr.get('boxed', False)
         ifcond = QAPISchemaIfCond(expr.get('if'))
+        info = expr.info
         features = self._make_features(expr.get('features'), info)
         if isinstance(data, OrderedDict):
             data = self._make_implicit_object_type(
                 name, info, ifcond,
                 'arg', self._make_members(data, info))
-        self._def_entity(QAPISchemaEvent(name, info, doc, ifcond, features,
-                                         data, boxed))
+        self._def_entity(QAPISchemaEvent(name, info, expr.doc, ifcond,
+                                         features, data, boxed))
 
     def _def_exprs(self, exprs):
-        for expr_elem in exprs:
-            expr = expr_elem['expr']
-            info = expr_elem['info']
-            doc = expr_elem.get('doc')
+        for expr in exprs:
             if 'enum' in expr:
-                self._def_enum_type(expr, info, doc)
+                self._def_enum_type(expr)
             elif 'struct' in expr:
-                self._def_struct_type(expr, info, doc)
+                self._def_struct_type(expr)
             elif 'union' in expr:
-                self._def_union_type(expr, info, doc)
+                self._def_union_type(expr)
             elif 'alternate' in expr:
-                self._def_alternate_type(expr, info, doc)
+                self._def_alternate_type(expr)
             elif 'command' in expr:
-                self._def_command(expr, info, doc)
+                self._def_command(expr)
             elif 'event' in expr:
-                self._def_event(expr, info, doc)
+                self._def_event(expr)
             elif 'include' in expr:
-                self._def_include(expr, info, doc)
+                self._def_include(expr)
             else:
                 assert False
 
-- 
2.39.0

[PULL 7/8] qapi: remove _JSONObject

[Markus Armbruster]

From: John Snow <jsnow@redhat.com>

We can remove this alias as it only has two usages now, and no longer
pays for the confusion of "yet another type".

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20230215000011.1725012-6-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
---
 scripts/qapi/expr.py   | 13 +++----------
 scripts/qapi/parser.py |  5 ++---
 2 files changed, 5 insertions(+), 13 deletions(-)

diff --git a/scripts/qapi/expr.py b/scripts/qapi/expr.py
index b8f905543e..ca01ea6f4a 100644
--- a/scripts/qapi/expr.py
+++ b/scripts/qapi/expr.py
@@ -47,14 +47,6 @@
 from .source import QAPISourceInfo
 
 
-# Deserialized JSON objects as returned by the parser.
-# The values of this mapping are not necessary to exhaustively type
-# here (and also not practical as long as mypy lacks recursive
-# types), because the purpose of this module is to interrogate that
-# type.
-_JSONObject = Dict[str, object]
-
-
 # See check_name_str(), below.
 valid_name = re.compile(r'(__[a-z0-9.-]+_)?'
                         r'(x-)?'
@@ -191,7 +183,7 @@ def check_defn_name_str(name: str, info: QAPISourceInfo, meta: str) -> None:
                 info, "%s name should not end in 'List'" % meta)
 
 
-def check_keys(value: _JSONObject,
+def check_keys(value: Dict[str, object],
                info: QAPISourceInfo,
                source: str,
                required: List[str],
@@ -255,7 +247,8 @@ def check_flags(expr: QAPIExpression) -> None:
             expr.info, "flags 'allow-oob' and 'coroutine' are incompatible")
 
 
-def check_if(expr: _JSONObject, info: QAPISourceInfo, source: str) -> None:
+def check_if(expr: Dict[str, object],
+             info: QAPISourceInfo, source: str) -> None:
     """
     Validate the ``if`` member of an object.
 
diff --git a/scripts/qapi/parser.py b/scripts/qapi/parser.py
index 50906e27d4..d570086e1a 100644
--- a/scripts/qapi/parser.py
+++ b/scripts/qapi/parser.py
@@ -42,9 +42,8 @@
 _ExprValue = Union[List[object], Dict[str, object], str, bool]
 
 
-# FIXME: Consolidate and centralize definitions for _ExprValue,
-# JSONValue, and _JSONObject; currently scattered across several
-# modules.
+# FIXME: Consolidate and centralize definitions for _ExprValue and
+# JSONValue; currently scattered across several modules.
 
 
 class QAPIExpression(Dict[str, object]):
-- 
2.39.0

[PULL 8/8] qapi: remove JSON value FIXME

[Markus Armbruster]

From: John Snow <jsnow@redhat.com>

With the two major JSON-ish type hierarchies clarified for distinct
purposes; QAPIExpression for parsed expressions and JSONValue for
introspection data, remove this FIXME as no longer an action item.

A third JSON-y data type, _ExprValue, is not meant to represent JSON in
the abstract but rather only the possible legal return values from a
single function, get_expr(). It isn't appropriate to attempt to merge it
with either of the above two types.

In theory, it may be possible to define a completely agnostic
one-size-fits-all JSON type hierarchy that any other user could borrow -
in practice, it's tough to wrangle the differences between invariant,
covariant and contravariant types: input and output parameters demand
different properties of such a structure.

However, QAPIExpression serves to authoritatively type user input to the
QAPI parser, while JSONValue serves to authoritatively type qapi
generator *output* to be served back to client users at runtime via
QMP. The AST for these two types are different and cannot be wholly
merged into a unified syntax.

They could, in theory, share some JSON primitive definitions. In
practice, this is currently more trouble than it's worth with mypy's
current expressive power. As such, declare this "done enough for now".

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20230215000011.1725012-7-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
---
 scripts/qapi/parser.py | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/scripts/qapi/parser.py b/scripts/qapi/parser.py
index d570086e1a..878f90b458 100644
--- a/scripts/qapi/parser.py
+++ b/scripts/qapi/parser.py
@@ -42,10 +42,6 @@
 _ExprValue = Union[List[object], Dict[str, object], str, bool]
 
 
-# FIXME: Consolidate and centralize definitions for _ExprValue and
-# JSONValue; currently scattered across several modules.
-
-
 class QAPIExpression(Dict[str, object]):
     # pylint: disable=too-few-public-methods
     def __init__(self,
-- 
2.39.0

Re: [PULL 0/8] QAPI patches patches for 2023-02-23

[Peter Maydell]

On Thu, 23 Feb 2023 at 12:23, Markus Armbruster <armbru@redhat.com> wrote:
>
> The following changes since commit 79b677d658d3d35e1e776826ac4abb28cdce69b8:
>
>   Merge tag 'net-pull-request' of https://github.com/jasowang/qemu into staging (2023-02-21 11:28:31 +0000)
>
> are available in the Git repository at:
>
>   https://repo.or.cz/qemu/armbru.git tags/pull-qapi-2023-02-23
>
> for you to fetch changes up to c7b7a7ded9376ad936cfedd843752789ca61bc3b:
>
>   qapi: remove JSON value FIXME (2023-02-23 13:01:45 +0100)
>
> ----------------------------------------------------------------
> QAPI patches patches for 2023-02-23
>


Applied, thanks.

Please update the changelog at https://wiki.qemu.org/ChangeLog/8.0
for any user-visible changes.

-- PMM