qapi: Dumb down QAPISchema.lookup_entity()

QAPISchema.lookup_entity() takes an optional type argument, a subtype
of QAPISchemaDefinition, and returns that type or None. Callers can
use this to save

qapi: Dumb down QAPISchema.lookup_entity()

QAPISchema.lookup_entity() takes an optional type argument, a subtype
of QAPISchemaDefinition, and returns that type or None. Callers can
use this to save themselves an isinstance() test.

The only remaining user of this convenience feature is .lookup_type().
But we don't actually save anything anymore there: we still need the
isinstance() to help mypy over the hump.

Drop the .lookup_entity() argument, and adjust .lookup_type().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-26-armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
[Commit message typo fixed]

show more ...

qapi: Tighten check whether implicit object type already exists

Entities with names starting with q_obj_ are implicit object types.
Therefore, QAPISchema._make_implicit_object_type()'s .lookup_entit

qapi: Tighten check whether implicit object type already exists

Entities with names starting with q_obj_ are implicit object types.
Therefore, QAPISchema._make_implicit_object_type()'s .lookup_entity()
can only return a QAPISchemaObjectType. Assert that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-25-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: John Snow <jsnow@redhat.com>

show more ...

qapi/schema: remove unnecessary asserts

With strict typing enabled, these runtime statements aren't necessary
anymore; we can prove them statically.

Signed-off-by: John Snow <jsnow@redhat.com>
Revi

qapi/schema: remove unnecessary asserts

With strict typing enabled, these runtime statements aren't necessary
anymore; we can prove them statically.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-24-armbru@redhat.com>

show more ...

qapi/schema: turn on mypy strictness

This patch can be rolled in with the previous one once the series is
ready for merge, but for work-in-progress' sake, it's separate here.

Signed-off-by: John Sn

qapi/schema: turn on mypy strictness

This patch can be rolled in with the previous one once the series is
ready for merge, but for work-in-progress' sake, it's separate here.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-23-armbru@redhat.com>

show more ...

qapi/schema: add type hints

This patch only adds type hints, which aren't utilized at runtime and
don't change the behavior of this module in any way.

In a scant few locations, type hints are remov

qapi/schema: add type hints

This patch only adds type hints, which aren't utilized at runtime and
don't change the behavior of this module in any way.

In a scant few locations, type hints are removed where no longer
necessary due to inference power from typing all of the rest of
creation; and any type hints that no longer need string quotes are
changed.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-22-armbru@redhat.com>

show more ...

qapi/parser.py: assert member.info is present in connect_member

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbr

qapi/parser.py: assert member.info is present in connect_member

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-21-armbru@redhat.com>

show more ...

qapi/parser: demote QAPIExpression to Dict[str, Any]

Dict[str, object] is a stricter type, but with the way that code is
currently arranged, it is infeasible to enforce this strictness.

In particul

qapi/parser: demote QAPIExpression to Dict[str, Any]

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 <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-20-armbru@redhat.com>

show more ...

qapi/schema: assert inner type of QAPISchemaVariants in check_clash()

QAPISchemaVariant's "variants" field is typed as
List[QAPISchemaVariant], where the typing for QAPISchemaVariant allows
its type

qapi/schema: assert inner type of QAPISchemaVariants in check_clash()

QAPISchemaVariant's "variants" field is typed as
List[QAPISchemaVariant], where the typing for QAPISchemaVariant allows
its type field to be any QAPISchemaType.

However, QAPISchemaVariant expects that all of its variants contain the
narrower QAPISchemaObjectType. This relationship is enforced at runtime
in QAPISchemaVariants.check(). This relationship is not embedded in the
type system though, so QAPISchemaVariants.check_clash() needs to
re-assert this property in order to call
QAPISchemaVariant.type.check_clash().

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-19-armbru@redhat.com>

show more ...

qapi/schema: fix typing for QAPISchemaVariants.tag_member

There are two related changes here:

(1) We need to perform type narrowing for resolving the type of
tag_member during check(), and

(2)

qapi/schema: fix typing for QAPISchemaVariants.tag_member

There are two related changes here:

(1) We need to perform type narrowing for resolving the type of
tag_member during check(), and

(2) tag_member is a delayed initialization field, but we can hide it
behind a property that raises an Exception if it's called too
early. This simplifies the typing in quite a few places and avoids
needing to assert that the "tag_member is not None" at a dozen
callsites, which can be confusing and suggest the wrong thing to a
drive-by contributor.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-18-armbru@redhat.com>

show more ...

qapi/schema: Don't initialize "members" with `None`

Declare, but don't initialize the "members" field with type
List[QAPISchemaObjectTypeMember].

This simplifies the typing from what would otherwis

qapi/schema: Don't initialize "members" with `None`

Declare, but don't initialize the "members" field with type
List[QAPISchemaObjectTypeMember].

This simplifies the typing from what would otherwise be
Optional[List[T]] to merely List[T]. This removes the need to add
assertions to several callsites that this value is not None - which it
never will be after the delayed initialization in check() anyway.

The type declaration without initialization trick will cause accidental
uses of this field prior to full initialization to raise an
AttributeError.

(Note that it is valid to have an empty members list, see the internal
q_empty object as an example. For this reason, we cannot use the empty
list as a replacement test for full initialization and instead rely on
the _checked/_check_complete fields.)

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-17-armbru@redhat.com>

show more ...

qapi/schema: add _check_complete flag

Instead of using the None value for the members field, use a dedicated
flag to detect recursive misconfigurations.

This is intended to assist with subsequent p

qapi/schema: add _check_complete flag

Instead of using the None value for the members field, use a dedicated
flag to detect recursive misconfigurations.

This is intended to assist with subsequent patches that seek to remove
the "None" value from the members field (which can never hold that value
after the final call to check()) in order to simplify the static typing
of that field; avoiding the need of assertions littered at many
callsites to eliminate the possibility of the None value.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-16-armbru@redhat.com>

show more ...

qapi/schema: assert info is present when necessary

QAPISchemaInfo arguments can often be None because built-in definitions
don't have such information. The type hint can only be
Optional[QAPISchema

qapi/schema: assert info is present when necessary

QAPISchemaInfo arguments can often be None because built-in definitions
don't have such information. The type hint can only be
Optional[QAPISchemaInfo] then. But, mypy gets upset about all the
places where we exploit that it can't actually be None there. Add
assertions that will help mypy over the hump, to enable adding type
hints in a forthcoming commit.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-15-armbru@redhat.com>

show more ...

qapi/schema: fix QAPISchemaArrayType.check's call to resolve_type

Adjust the expression at the callsite to work around mypy's weak type
introspection that believes this expression can resolve to
QAP

qapi/schema: fix QAPISchemaArrayType.check's call to resolve_type

Adjust the expression at the callsite to work around mypy's weak type
introspection that believes this expression can resolve to
QAPISourceInfo; it cannot.

(Fundamentally: self.info only resolves to false in a boolean expression
when it is None; therefore this expression may only ever produce
Optional[str]. mypy does not know that 'info', when it is a
QAPISourceInfo object, cannot ever be false.)

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-14-armbru@redhat.com>

show more ...

qapi: Assert built-in types exist

QAPISchema.lookup_type('FOO') returns a QAPISchemaType when type 'FOO'
exists, else None. It won't return None for built-in types like
'int'.

Since mypy can't see

qapi: Assert built-in types exist

QAPISchema.lookup_type('FOO') returns a QAPISchemaType when type 'FOO'
exists, else None. It won't return None for built-in types like
'int'.

Since mypy can't see that, it'll complain that we assign the
Optional[QAPISchemaType] returned by .lookup_type() to QAPISchemaType
variables.

Add assertions to help it over the hump.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-13-armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>

show more ...

qapi/schema: assert resolve_type has 'info' and 'what' args on error

resolve_type() is generally used to resolve configuration-provided type
names into type objects, and generally requires valid 'in

qapi/schema: assert resolve_type has 'info' and 'what' args on error

resolve_type() is generally used to resolve configuration-provided type
names into type objects, and generally requires valid 'info' and 'what'
parameters.

In some cases, such as with QAPISchemaArrayType.check(), resolve_type
may be used to resolve built-in types and as such will not have an
'info' argument, but also must not fail in this scenario.

Use an assertion to sate mypy that we will indeed have 'info' and 'what'
parameters for the error pathway in resolve_type.

Note: there are only three callsites to resolve_type at present where
"info" is perceived by mypy to be possibly None:

1) QAPISchemaArrayType.check()
2) QAPISchemaObjectTypeMember.check()
3) QAPISchemaEvent.check()

Of those three, only the first actually ever passes None; the other two
are limited by their base class initializers which accept info=None, but
neither subclass actually use a None value in practice, currently.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-12-armbru@redhat.com>

show more ...

qapi/schema: add type narrowing to lookup_type()

This function is a bit hard to type as-is; mypy needs some assertions to
assist with the type narrowing.

Signed-off-by: John Snow <jsnow@redhat.com>

qapi/schema: add type narrowing to lookup_type()

This function is a bit hard to type as-is; mypy needs some assertions to
assist with the type narrowing.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-11-armbru@redhat.com>

show more ...

qapi/schema: adjust type narrowing for mypy's benefit

We already take care to perform some type narrowing for arg_type and
ret_type, but not in a way where mypy can utilize the result once we add
ty

qapi/schema: adjust type narrowing for mypy's benefit

We already take care to perform some type narrowing for arg_type and
ret_type, but not in a way where mypy can utilize the result once we add
type hints, e.g.:

qapi/schema.py:833: error: Incompatible types in assignment (expression
has type "QAPISchemaType", variable has type
"Optional[QAPISchemaObjectType]") [assignment]

qapi/schema.py:893: error: Incompatible types in assignment (expression
has type "QAPISchemaType", variable has type
"Optional[QAPISchemaObjectType]") [assignment]

A simple change to use a temporary variable helps the medicine go down.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-10-armbru@redhat.com>

show more ...

qapi/schema: make c_type() and json_type() abstract methods

These methods should always return a str, it's only the default abstract
implementation that doesn't. They can be marked "abstract", which

qapi/schema: make c_type() and json_type() abstract methods

These methods should always return a str, it's only the default abstract
implementation that doesn't. They can be marked "abstract", which
requires subclasses to override the method with the proper return type.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-9-armbru@redhat.com>

show more ...

qapi/schema: declare type for QAPISchemaArrayType.element_type

A QAPISchemaArrayType's element type gets resolved only during .check().
We have QAPISchemaArrayType.__init__() initialize self.element

qapi/schema: declare type for QAPISchemaArrayType.element_type

A QAPISchemaArrayType's element type gets resolved only during .check().
We have QAPISchemaArrayType.__init__() initialize self.element_type =
None, and .check() assign the actual type. Using .element_type before
.check() is wrong, and hopefully crashes due to the value being None.
Works.

However, it makes for awkward typing. With .element_type:
Optional[QAPISchemaType], mypy is of course unable to see that it's None
before .check(), and a QAPISchemaType after. To help it over the hump,
we'd have to assert self.element_type is not None before all the (valid)
uses. The assertion catches invalid uses, but only at run time; mypy
can't flag them.

Instead, declare .element_type in .__init__() as QAPISchemaType
*without* initializing it. Using .element_type before .check() now
certainly crashes, which is an improvement. Mypy still can't flag
invalid uses, but that's okay.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-8-armbru@redhat.com>

show more ...

qapi/schema: declare type for QAPISchemaObjectTypeMember.type

A QAPISchemaObjectTypeMember's type gets resolved only during .check().
We have QAPISchemaObjectTypeMember.__init__() initialize self.ty

qapi/schema: declare type for QAPISchemaObjectTypeMember.type

A QAPISchemaObjectTypeMember's type gets resolved only during .check().
We have QAPISchemaObjectTypeMember.__init__() initialize self.type =
None, and .check() assign the actual type. Using .type before .check()
is wrong, and hopefully crashes due to the value being None. Works.

However, it makes for awkward typing. With .type:
Optional[QAPISchemaType], mypy is of course unable to see that it's None
before .check(), and a QAPISchemaType after. To help it over the hump,
we'd have to assert self.type is not None before all the (valid) uses.
The assertion catches invalid uses, but only at run time; mypy can't
flag them.

Instead, declare .type in .__init__() as QAPISchemaType *without*
initializing it. Using .type before .check() now certainly crashes,
which is an improvement. Mypy still can't flag invalid uses, but that's
okay.

Addresses typing errors such as these:

qapi/schema.py:657: error: "None" has no attribute "alternate_qtype" [attr-defined]
qapi/schema.py:662: error: "None" has no attribute "describe" [attr-defined]

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-7-armbru@redhat.com>

show more ...

qapi: create QAPISchemaDefinition

Include entities don't have names, but we generally expect "entities" to
have names. Reclassify all entities with names as *definitions*, leaving
the nameless inclu

qapi: create QAPISchemaDefinition

Include entities don't have names, but we generally expect "entities" to
have names. Reclassify all entities with names as *definitions*, leaving
the nameless include entities as QAPISchemaEntity instances.

This is primarily to help simplify typing around expectations of what
callers expect for properties of an "entity".

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-6-armbru@redhat.com>

show more ...

qapi/schema: add pylint suppressions

With this patch, pylint is happy with the file, so enable it in the
configuration.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <a

qapi/schema: add pylint suppressions

With this patch, pylint is happy with the file, so enable it in the
configuration.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-5-armbru@redhat.com>

show more ...

qapi: sort pylint suppressions

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Marku

qapi: sort pylint suppressions

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-4-armbru@redhat.com>

show more ...

qapi/parser: shush up pylint

Shhh!

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <2

qapi/parser: shush up pylint

Shhh!

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-3-armbru@redhat.com>

show more ...

qapi/parser: fix typo - self.returns.info => self.errors.info

Small copy-pasto. The correct info field to use in this conditional
block is self.errors.info.

Fixes: 3a025d3d1ffa
Signed-off-by: John

qapi/parser: fix typo - self.returns.info => self.errors.info

Small copy-pasto. The correct info field to use in this conditional
block is self.errors.info.

Fixes: 3a025d3d1ffa
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-2-armbru@redhat.com>

show more ...