Commit Graph

53 Commits

Author SHA1 Message Date
Markus Armbruster b6c18755e4 qapi: Add feature flags to enum members
This is quite similar to commit 84ab008687 "qapi: Add feature flags to
struct members", only for enums instead of structs.

Special feature flag 'deprecated' is silently ignored there.  This is
okay only because it will be implemented shortly.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20211025042405.3762351-3-armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2021-10-27 17:18:55 +02:00
Markus Armbruster 75ecee7262 qapi: Enable enum member introspection to show more than name
The next commit will add feature flags to enum members.  There's a
problem, though: query-qmp-schema shows an enum type's members as an
array of member names (SchemaInfoEnum member @values).  If it showed
an array of objects with a name member, we could simply add more
members to these objects.  Since it's just strings, we can't.

I can see three ways to correct this design mistake:

1. Do it the way we should have done it, plus compatibility goo.

   We want a ['SchemaInfoEnumMember'] member in SchemaInfoEnum.  Since
   changing @values would be a compatibility break, add a new member
   @members instead.

   @values is now redundant.  In my testing, output of
   qemu-system-x86_64's query-qmp-schema grows by 11% (18.5KiB).

   We can deprecate @values now and drop it later.  This will break
   outmoded clients.  Well-behaved clients such as libvirt are
   expected to break cleanly.

2. Like 1, but omit "boring" elements of @member, and empty @member.

   @values does not become redundant.  @members augments it.  Somewhat
   cumbersome, but output of query-qmp-schema grows only as we make
   enum members non-boring.

   There is nothing to deprecate here.

3. Versioned query-qmp-schema.

   query-qmp-schema provides either @values or @members.  The QMP
   client can select which version it wants.  There is no redundant
   output.

   We can deprecate old versions and eventually drop them.  This will
   break outmoded clients.  Breaking cleanly is easier than for 1.

   While 1 and 2 operate within the common rules for compatible
   evolution apply (section "Compatibility considerations" in
   docs/devel/qapi-code-gen.rst), 3 bypasses them.  Attractive when
   operating within the rules is just too awkward.  Not the case here.

This commit implements 1.  Libvirt developers prefer it.

Deprecate @values in favour of @members.  Since query-qmp-schema
compatibility is pretty fundamental for management applications, an
extended grace period is advised.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Tested-by: Peter Krempa <pkrempa@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Message-Id: <20211025042405.3762351-2-armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2021-10-27 17:18:43 +02:00
Markus Armbruster 1889e57a71 qapi: Simplify QAPISchemaIfCond's interface for generating C
QAPISchemaIfCond.cgen() is only ever used like

    gen_if(ifcond.cgen())

and

    gen_endif(ifcond.cgen())

Simplify to

    ifcond.gen_if()

and

    ifcond.gen_endif()

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210831123809.1107782-2-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[Import statements tidied up with isort]
2021-09-03 17:06:40 +02:00
Marc-André Lureau 6cc2e4817f qapi: introduce QAPISchemaIfCond.cgen()
Instead of building prepocessor conditions from a list of string, use
the result generated from QAPISchemaIfCond.cgen() and hide the
implementation details.

Note: this patch introduces a minor regression, generating a redundant
pair of parenthesis. This is mostly fixed in a later patch in this
series ("qapi: replace if condition list with dict [..]")

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20210804083105.97531-5-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-08-26 13:53:56 +02:00
Marc-André Lureau 33aa3267ba qapi: add QAPISchemaIfCond.is_present()
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210804083105.97531-4-marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-08-26 13:53:56 +02:00
Marc-André Lureau f17539c80d qapi: wrap Sequence[str] in an object
Mechanical change, except for a new assertion in
QAPISchemaEntity.ifcond().

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20210804083105.97531-3-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Rebased with obvious conflicts, commit message adjusted]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-08-26 13:53:56 +02:00
John Snow 9b77d94699 qapi/introspect.py: set _gen_tree's default ifcond argument to ()
We don't need to create an empty, mutable list to pass to _gen_tree;
since it is now typed as a Sequence, we can use the empty tuple as a
default and omit the argument.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-19-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 19:51:14 +01:00
John Snow cea53c31b7 qapi/introspect.py: Type _gen_tree variants as Sequence[str]
Optional[List] is clunky; an empty sequence can more elegantly convey
"no variants". By downgrading "List" to "Sequence", we can also accept
tuples; this is useful for the empty tuple specifically, which we may
use as a default parameter because it is immutable.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-18-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Doc string touched up]
Reviewed-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 19:51:08 +01:00
John Snow cf26906c4a qapi/introspect.py: Update copyright and authors list
To reflect the work that went into strictly typing introspect.py,
punish myself by claiming credit.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-17-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 19:50:26 +01:00
John Snow 5444dedfc7 qapi/introspect.py: Add docstrings to _gen_tree and _tree_to_qlit
Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-16-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Doc string improvements squashed in]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 19:50:23 +01:00
John Snow 82b52f6b84 qapi/introspect.py: add type hint annotations
NB: The type aliases (SchemaInfo et al) declare intent for some of the
"dictly-typed" objects we pass around in introspect.py. They do not
enforce the shape of those objects, and cannot, until Python 3.7 or
later. (And even then, it may not be "worth it".)

Annotations are also added to the QAPISchemaEntity __init__ method in
schema.py to allow mypy to statically prove the type of typ.name,
needed to prove the return type of
QAPISchemaGenIntrospectVisitor._use_type().

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-15-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Note on QAPISchemaEntity.__init__() squashed into commit message,
Comment wrapped to conform to PEP 8]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 19:45:20 +01:00
John Snow cf5db2142b qapi/introspect.py: remove _gen_variants helper
It is easier to give a name to all of the dictly-typed objects we pass
around in introspect.py by removing this helper, as it does not return
an object that has any knowable type by itself.

Inline it into its only caller instead.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-14-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 19:45:20 +01:00
John Snow c0e8d9f3c1 qapi/introspect.py: improve readability of _tree_to_qlit
Subjective, but I find getting rid of the comprehensions helps. Also,
divide the sections into scalar and non-scalar sections, and remove
old-style string formatting.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-13-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 19:45:20 +01:00
John Snow 2a6c161bbf qapi/introspect.py: improve _tree_to_qlit error message
Trivial; make the error message just a pinch more explicit in case we
trip this by accident in the future.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-12-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 19:45:20 +01:00
John Snow 4f7f97a7b3 qapi/introspect.py: create a typed 'Annotated' data strutcure
Presently, we use a tuple to attach a dict containing annotations
(comments and compile-time conditionals) to a tree node. This is
undesirable because dicts are difficult to strongly type; promoting it
to a real class allows us to name the values and types of the
annotations we are expecting.

In terms of typing, the Annotated<T> type serves as a generic container
where the annotated node's type is preserved, allowing for greater
specificity than we'd be able to provide without a generic.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-11-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 19:45:17 +01:00
John Snow 9db2734613 qapi/introspect.py: Introduce preliminary tree typing
The types will be used in forthcoming patches to add typing. These types
describe the layout and structure of the objects passed to
_tree_to_qlit, but lack the power to describe annotations until the next
commit.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-10-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 19:38:00 +01:00
John Snow d4c5b429fd qapi/introspect.py: Always define all 'extra' dict keys
This mimics how a typed object works, where 'if' and 'comment' are
always set, regardless of if they have a value set or not.

It is safe to do this because of the way that _tree_to_qlit processes
these values (using dict.get with a default of None), resulting in no
change of output from _tree_to_qlit. There are no other users of this
data.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-9-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 19:37:54 +01:00
John Snow 5f50cede4a qapi/introspect.py: replace 'extra' dict with 'comment' argument
This is only used to pass in a dictionary with a comment already set, so
skip the runaround and just accept the (optional) comment.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-8-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 19:37:49 +01:00
John Snow 84cf09915f qapi/introspect.py: Unify return type of _make_tree()
Returning two different types conditionally can be complicated to
type. Return one type for consistency.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-7-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 19:37:41 +01:00
John Snow 055569603d qapi/introspect.py: guard against ifcond/comment misuse
_tree_to_qlit is called recursively on dict values (isolated from their
keys); at such a point in generating output it is too late to apply an
ifcond. Similarly, comments do not necessarily have a "tidy" place they
can be printed in such a circumstance.

Forbid this usage by renaming "suppress_first_indent" to "dict_value" to
emphasize that indents are suppressed only for the benefit of dict
values; then add an assertion assuring we do not pass ifcond/comments
in this case.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-6-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Comment wrapped to conform to PEP 8]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 19:37:28 +01:00
John Snow 84bece7dd4 qapi/introspect.py: add _gen_features helper
_make_tree might receive a dict (a SchemaInfo object) or some other type
(usually, a string) for its obj parameter. Adding features information
should arguably be performed by the caller at such a time when we know
the type of the object and don't have to re-interrogate it.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-5-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 19:37:20 +01:00
John Snow d70f5130f6 qapi/introspect.py: use _make_tree for features nodes
At present, we open-code this in _make_tree itself; but if the structure
of the tree changes, this is brittle. Use an explicit recursive call to
_make_tree when appropriate to help keep the interior node typing
consistent.

A consequence of doing this is that the 'ifcond' key of the features
dict will be omitted when ifcond is false-ish, just like it is omitted
in top-level calls to _make_tree. This also increases consistency in our
handling of this property.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-4-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 19:37:13 +01:00
John Snow 6b67bcac0f qapi/introspect.py: assert schema is not None
The introspect visitor is stateful, but expects that it will have a
schema to refer to. Add assertions that state this.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-3-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 19:35:11 +01:00
John Snow 67fea57502 qapi: enforce import order/styling with isort
While we're mucking around with imports, we might as well formalize the
style we use. Let's use isort to do it for us.

lines_after_imports=2: Use two lines after imports, to match PEP8's
desire to have "two lines before and after" class definitions, which are
likely to start immediately after imports.

force_sort_within_sections: Intermingles "from x" and "import x" style
statements, such that sorting is always performed strictly on the module
name itself.

force_grid_wrap=4: Four or more imports from a single module will force
the one-per-line style that's more git-friendly. This will generally
happen for 'typing' imports.

multi_line_output=3: Uses the one-per-line indented style for long
imports.

include_trailing_comma: Adds a comma to the last import in a group,
which makes git conflicts nicer to deal with, generally.

line_length: 72 is chosen to match PEP8's "docstrings and comments" line
length limit. If you have a single line import that exceeds 72
characters, your names are too long!

Suggested-by: Cleber Rosa <crosa@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Tested-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201009161558.107041-8-jsnow@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-10-10 11:37:47 +02:00
John Snow 5af8263d40 qapi: Remove wildcard includes
Wildcard includes become hard to manage when refactoring and dealing
with circular dependencies with strictly typed mypy.

flake8 also flags each one as a warning, as it is not smart enough to
know which names exist in the imported file.

Remove them and include things explicitly by name instead.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20201009161558.107041-7-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-10-10 11:37:47 +02:00
John Snow 7137a96099 qapi: Prefer explicit relative imports
All of the QAPI include statements are changed to be package-aware, as
explicit relative imports.

A quirk of Python packages is that the name of the package exists only
*outside* of the package. This means that to a module inside of the qapi
folder, there is inherently no such thing as the "qapi" package. The
reason these imports work is because the "qapi" package exists in the
context of the caller -- the execution shim, where sys.path includes a
directory that has a 'qapi' folder in it.

When we write "from qapi import sibling", we are NOT referencing the folder
'qapi', but rather "any package named qapi in sys.path". If you should
so happen to have a 'qapi' package in your path, it will use *that*
package.

When we write "from .sibling import foo", we always reference explicitly
our sibling module; guaranteeing consistency in *where* we are importing
these modules from.

This can be useful when working with virtual environments and packages
in development mode. In development mode, a package is installed as a
series of symlinks that forwards to your same source files. The problem
arises because code quality checkers will follow "import qapi.x" to the
"installed" version instead of the sibling file and -- even though they
are the same file -- they have different module paths, and this causes
cyclic import problems, false positive type mismatch errors, and more.

It can also be useful when dealing with hierarchical packages, e.g. if
we allow qemu.core.qmp, qemu.qapi.parser, etc.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20201009161558.107041-6-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-10-10 11:37:47 +02:00
Kevin Wolf 04f22362f1 qapi: Add a 'coroutine' flag for commands
This patch adds a new 'coroutine' flag to QMP command definitions that
tells the QMP dispatcher that the command handler is safe to be run in a
coroutine.

The documentation of the new flag pretends that this flag is already
used as intended, which it isn't yet after this patch. We'll implement
this in another patch in this series.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20201005155855.256490-9-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-10-09 07:08:19 +02:00
Markus Armbruster 84ab008687 qapi: Add feature flags to struct members
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200317115459.31821-21-armbru@redhat.com>
2020-03-17 21:25:47 +01:00
Markus Armbruster 24cfd6addd qapi/introspect: Factor out _make_tree()
The value of @qmp_schema_qlit is generated from an expression tree.
Tree nodes are created in several places.  Factor out the common code
into _make_tree().  This isn't much of a win now.  It will pay off
when we add feature flags in the next few commits.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200317115459.31821-16-armbru@redhat.com>
2020-03-17 19:58:34 +01:00
Markus Armbruster 2e8a843d19 qapi/introspect: Rename *qlit* to reduce confusion
We generate the value of qmp_schema_qlit from an expression tree.  The
function doing that is named to_qlit(), and its inputs are accumulated
in QAPISchemaGenIntrospectVisitor._qlits.  We call both its input and
its output "qlit".  This is confusing.

Use "tree" for input, and "qlit" only for output: rename to_qlit() to
_tree_to_qlit(), ._qlits to ._trees, ._gen_qlit() to ._gen_tree().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200317115459.31821-15-armbru@redhat.com>
2020-03-17 19:58:34 +01:00
Markus Armbruster 7b3bc9e28f qapi: Consistently put @features parameter right after @ifcond
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200317115459.31821-14-armbru@redhat.com>
2020-03-17 19:58:34 +01:00
Markus Armbruster 013b4efc9b qapi: Add feature flags to remaining definitions
In v4.1.0, we added feature flags just to struct types (commit
6a8c0b5102^..f3ed93d545), to satisfy an immediate need (commit
c9d4070991 "file-posix: Add dynamic-auto-read-only QAPI feature").  In
v4.2.0, we added them to commands (commit 23394b4c39 "qapi: Add
feature flags to commands") to satisfy another immediate need (commit
d76744e65e "qapi: Allow introspecting fix for savevm's cooperation
with blockdev").

Add them to the remaining definitions: enumeration types, union types,
alternate types, and events.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200317115459.31821-13-armbru@redhat.com>
2020-03-17 19:58:34 +01:00
Markus Armbruster 8ec0e1a4e6 qapi: Brush off some (py)lint
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200304155932.20452-5-armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2020-03-05 09:24:11 +01:00
Markus Armbruster 2cae67bcb5 qapi: Use super() now we have Python 3
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200304155932.20452-4-armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2020-03-05 09:24:11 +01:00
Peter Krempa 23394b4c39 qapi: Add feature flags to commands
Similarly to features for struct types introduce the feature flags also
for commands. This will allow notifying management layers of fixes and
compatible changes in the behaviour of a command which may not be
detectable any other way.

The changes were heavily inspired by commit 6a8c0b5102.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20191018081454.21369-3-armbru@redhat.com>
2019-10-22 13:54:13 +02:00
Markus Armbruster e6c42b96b9 qapi: Split up scripts/qapi/common.py
The QAPI code generator clocks in at some 3100 SLOC in 8 source files.
Almost 60% of the code is in qapi/common.py.  Split it into more
focused modules:

* Move QAPISchemaPragma and QAPISourceInfo to qapi/source.py.

* Move QAPIError and its sub-classes to qapi/error.py.

* Move QAPISchemaParser and QAPIDoc to parser.py.  Use the opportunity
  to put QAPISchemaParser first.

* Move check_expr() & friends to qapi/expr.py.  Use the opportunity to
  put the code into a more sensible order.

* Move QAPISchema & friends to qapi/schema.py

* Move QAPIGen and its sub-classes, ifcontext,
  QAPISchemaModularCVisitor, and QAPISchemaModularCVisitor to qapi/gen.py

* Delete camel_case(), it's unused since commit e98859a9b9 "qapi:
  Clean up after recent conversions to QAPISchemaVisitor"

A number of helper functions remain in qapi/common.py.  I considered
moving the code generator helpers to qapi/gen.py, but decided not to.
Perhaps we should rewrite them as methods of QAPIGen some day.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20191018074345.24034-7-armbru@redhat.com>
[Add "# -*- coding: utf-8 -*-" lines]
2019-10-22 13:53:55 +02:00
Kevin Wolf 6a8c0b5102 qapi: Add feature flags to struct types
Sometimes, the behaviour of QEMU changes without a 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
they can rely on the changed behavior.

Let's add feature flags to the QAPI schema language, so that we can make
such changes visible with schema introspection.

An example for a schema definition using feature flags looks like this:

    { 'struct': 'TestType',
      'data': { 'number': 'int' },
      'features': [ 'allow-negative-numbers' ] }

Introspection information then looks like this:

    { "name": "TestType", "meta-type": "object",
      "members": [
          { "name": "number", "type": "int" } ],
      "features": [ "allow-negative-numbers" ] }

This patch implements feature flags only for struct types. We'll
implement them more widely as needed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20190606153803.5278-2-armbru@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-06-12 18:34:26 +02:00
Marc-André Lureau 8ee06f61e1 qapi: Add #if conditions to generated code members
Wrap generated enum and struct members and their supporting code with
#if/#endif, using the .ifcond members added in the previous patches.

We do enum and struct in a single patch because union tag enum and the
associated variants tie them together, and dealing with that to split
the patch doesn't seem worthwhile.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20181213123724.4866-18-marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-12-14 06:52:48 +01:00
Marc-André Lureau 1962bd39d5 qapi: change enum visitor and gen_enum* to take QAPISchemaMember
This will allow to add and access more properties associated with enum
values/members, like the associated 'if' condition. We may want to
have a specialized type QAPISchemaEnumMember, for now this will do.

Modify gen_enum() and gen_enum_lookup() for the same reason.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20181213123724.4866-3-marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-12-13 19:20:11 +01:00
Eric Blake 8c643361ee qapi: Add comments to aid debugging generated introspection
We consciously chose in commit 1a9a507b to hide QAPI type names
from the introspection output on the wire, but added a command
line option -u to unmask the type name when doing a debug build.
The unmask option still remains useful to some other forms of
automated analysis, so it will not be removed; however, when it
is not in use, the generated .c file can be hard to read.  At
the time when we first introduced masking, the generated file
consisted only of a monolithic C string, so there was no clean
way to inject any comments.

Later, in commit 7d0f982b, we switched the generation to output
a QLit object, in part to make it easier for future addition of
conditional compilation.  In fact, commit d626b6c1 took advantage
of this by passing a tuple instead of a bare object for encoding
the output of conditionals.  By extending that tuple, we can now
interject strategic comments.

For now, type name debug aid comments are only output once per
meta-type, rather than at all uses of the number used to encode
the type within the introspection data.  But this is still a lot
more convenient than having to regenerate the file with the
unmask operation temporarily turned on - merely search the
generated file for '"NNN" =' to learn the corresponding source
name and associated definition of type NNN.

The generated qapi-introspect.c changes only with the addition
of comments, such as:

| @@ -14755,6 +15240,7 @@
|          { "name", QLIT_QSTR("[485]"), },
|          {}
|      })),
| +    /* "485" = QCryptoBlockInfoLUKSSlot */
|      QLIT_QDICT(((QLitDictEntry[]) {
|          { "members", QLIT_QLIST(((QLitObject[]) {
|              QLIT_QDICT(((QLitDictEntry[]) {

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180827213943.33524-3-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Rebased, update to qapi-code-gen.txt corrected]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-08-28 18:21:38 +02:00
Eric Blake 1aa806ccf0 qapi: Minor introspect.py cleanups
Commit 7d0f982b changed generated introspection output to no longer
produce long lines in the generated .c file, but failed to adjust
comments to match.  Add some clarity that the shorter length that
matters most is the overall QMP response on the wire.

Commit 25b1ef31 triggers a pep8 formatting nit.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180827213943.33524-2-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-08-28 18:21:38 +02:00
Markus Armbruster 25b1ef31db qapi: Make 'allow-oob' optional in SchemaInfoCommand
Making 'allow-oob' optional in SchemaInfoCommand permits omitting it
in the common case.  Shrinks query-qmp-schema's output from 122.1KiB
to 118.6KiB for me.

Note that out-of-band execution is still experimental (you have to
configure the monitor with x-oob=on to use it).

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180718090557.17248-1-armbru@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
2018-07-23 13:57:52 +02:00
Markus Armbruster 1f214ee1b8 qapi: Do not expose "allow-preconfig" in query-qmp-schema
According to commit 047f7038f5, option --preconfig

    [...] allows pausing QEMU in the new RUN_STATE_PRECONFIG state,
    allowing the configuration of QEMU from QMP before the machine
    jumps into board initialization code of machine_run_board_init()

    The intent is to allow management to query machine state and
    additionally configure it using previous query results within one
    QEMU instance (i.e. eliminate the need to start QEMU twice, 1st to
    query board specific parameters and 2nd for actual VM start using
    query results for additional parameters).

The implementation is a bit of a hack: it splices in an additional
main loop before machine creation, in special runstate preconfig.  New
command exit-preconfig exits that main loop.  QEMU continues
initializing, creates the machine, and runs the good old main loop.
The replacement of the main loop is transparent to monitors.

Sadly, some commands expect initialization to be complete.  Running
them in --preconfig's main loop violates their preconditions.  Since
we don't really know which commands are safe, we use a whitelist.
This drags the concept of run state into the QMP core.

The whitelist is done as a command flag in the QAPI schema (commit
d6fe3d02e9).  Drags the concept of run state further into the QAPI
language.

The command flag is exposed in query-qmp-schema (also commit
d6fe3d02e9).  This makes it ABI.

I consider the whole thing an offensively ugly hack, but sometimes an
ugly hack is the best we can do to solve a problem people have.

The need described by the commit message quote above is genuine.  The
proper solution would be a main loop that permits complete
configuration via QMP.  This is out of reach, thus the hack.

However, even though the need is genuine, it isn't urgent: libvirt is
not going to use this anytime soon.  Baking a hack into ABI before it
has any users is a bad idea.

This commit reverts the parts of commit d6fe3d02e9 that affect ABI
via query-qmp-schema.  The commit did the following:

(1) Add command flag 'allow-preconfig' to the QAPI schema language

(2) Pass it to code generators

(3) Have the commands.py code generator pass it to the command
    registry (so commit 047f7038f5 can use it as whitelist)

(4) Add 'allow-preconfig' to SchemaInfoCommand (neglecting to update
    qapi-code-gen.txt section "Client JSON Protocol introspection")

(5) Set 'allow-preconfig': true for commands qmp_capabilities,
    query-commands, query-command-line-options, query-status

Revert exactly (4), plus a bit of documentation added to
qemu-tech.info in commit 047f7038f5.

Shrinks query-qmp-schema's output from 126.5KiB to 121.8KiB for me.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180705091402.26244-2-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Igor Mammedov <imammedo@redhat.com>
[Straightforward conflict with commit d626b6c1ae resolved]
2018-07-16 15:35:57 +02:00
Marc-André Lureau d626b6c1ae qapi-introspect: add preprocessor conditions to generated QLit
This commit adds 'ifcond' conditions to top-level QLit objects.
Future work will add them to object and enum type members, i.e. within
QLit objects.

Extend the QLit generator to_qlit() to accept (@obj, @cond) tuples in
addition to just @obj.  The tuple causes the QLit generated for
objects for @obj with #if/#endif conditions for @cond.

See generated tests/test-qmp-introspect.c. Example diff after this
patch:

    --- before	2018-01-08 11:55:24.757083654 +0100
    +++ tests/test-qmp-introspect.c	2018-01-08 13:08:44.477641629 +0100
    @@ -51,6 +51,8 @@
             { "name", QLIT_QSTR("EVENT_F"), },
             {}
         })),
    +#if defined(TEST_IF_CMD)
    +#if defined(TEST_IF_STRUCT)
         QLIT_QDICT(((QLitDictEntry[]) {
             { "arg-type", QLIT_QSTR("5"), },
             { "meta-type", QLIT_QSTR("command"), },
    @@ -58,12 +60,16 @@
             { "ret-type", QLIT_QSTR("0"), },
             {}
         })),
    +#endif /* defined(TEST_IF_STRUCT) */
    +#endif /* defined(TEST_IF_CMD) */

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180703155648.11933-9-marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-07-03 18:38:54 +02:00
Marc-André Lureau 40bb13766a qapi-introspect: modify to_qlit() to append ',' on level > 0
The following patch is going to break list entries with #if/#endif, so
they should have the trailing ',' as suffix.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180703155648.11933-8-marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-07-03 18:38:53 +02:00
Marc-André Lureau fbf09a2fa4 qapi: add 'ifcond' to visitor methods
Modify the test visitor to check correct passing of values.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180703155648.11933-5-marcandre.lureau@redhat.com>
[Accidental change to roms/seabios dropped]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-07-03 18:38:53 +02:00
Markus Armbruster da112e83c1 qapi/introspect: Eliminate pointless variable in .visit_end()
Commit 1a9a507b2e "qapi-introspect: Hide type names" added local
variable @jsons to improve sorting, but also removed the sorting.  It
was part of a big series that went to v8, and it made sense until v2
or so...

Commit 7d0f982bfb replaced @jsons by @qlits, preserving the
uselessness.

Get rid of it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180620124742.16979-1-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2018-06-22 16:33:47 +02:00
Igor Mammedov d6fe3d02e9 qapi: introduce new cmd option "allow-preconfig"
New option will be used to allow commands, which are prepared/need
to run, during preconfig state. Other commands that should be able
to run in preconfig state, should be amended to not expect machine
in initialized state or deal with it.

For compatibility reasons, commands that don't use new flag
'allow-preconfig' explicitly are not permitted to run in
preconfig state but allowed in all other states like they used
to be.

Within this patch allow following commands in preconfig state:
   qmp_capabilities
   query-qmp-schema
   query-commands
   query-command-line-options
   query-status
   exit-preconfig
to allow qmp connection, basic introspection and moving to the next
state.

PS:
set-numa-node and query-hotpluggable-cpus will be enabled later in
a separate patches.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <1526057503-39287-1-git-send-email-imammedo@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[ehabkost: Changed "since 2.13" to "since 3.0"]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2018-05-30 13:19:09 -03:00
Peter Xu 876c67512e qapi: introduce new cmd option "allow-oob"
Here "oob" stands for "Out-Of-Band".  When "allow-oob" is set, it means
the command allows out-of-band execution.

The "oob" idea is proposed by Markus Armbruster in following thread:

  https://lists.gnu.org/archive/html/qemu-devel/2017-09/msg02057.html

This new "allow-oob" boolean will be exposed by "query-qmp-schema" as
well for command entries, so that QMP clients can know which commands
can be used in out-of-band calls. For example the command "migrate"
originally looks like:

  {"name": "migrate", "ret-type": "17", "meta-type": "command",
   "arg-type": "86"}

And it'll be changed into:

  {"name": "migrate", "ret-type": "17", "allow-oob": false,
   "meta-type": "command", "arg-type": "86"}

This patch only provides the QMP interface level changes.  It does not
contain the real out-of-band execution implementation yet.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180309090006.10018-18-peterx@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: rebase on introspection done by qlit]
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-19 14:58:37 -05:00
Marc-André Lureau 7d0f982bfb qapi: generate a literal qobject for introspection
Replace the generated json string with a literal qobject. The later is
easier to deal with, at run time as well as compile time: adding #if
conditionals will be easier than in a json string.

The output of query-qmp-schema is not changed.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180305172951.2150-5-marcandre.lureau@redhat.com>
[eblake: fix python 3 failure]
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-19 10:00:14 -05:00