object_property_get_enum() is the only object_property_FOO() that is
documented to return an undefined value on error. It does no such
thing, actually: it returns 0 on some errors, and -1 on others.
Needlessly complicated. Always return -1 on error, and adjust the
contract.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200917125540.597786-2-armbru@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
object_class_dynamic_cast_assert() is not used by
INTERFACE_CHECK, remove misleading mention of that function in
the documentation.
Message-Id: <20200916193101.511600-2-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Some typedefs and macros are defined after the type check macros.
This makes it difficult to automatically replace their
definitions with OBJECT_DECLARE_TYPE.
Patch generated using:
$ ./scripts/codeconverter/converter.py -i \
--pattern=QOMStructTypedefSplit $(git grep -l '' -- '*.[ch]')
which will split "typdef struct { ... } TypedefName"
declarations.
Followed by:
$ ./scripts/codeconverter/converter.py -i --pattern=MoveSymbols \
$(git grep -l '' -- '*.[ch]')
which will:
- move the typedefs and #defines above the type check macros
- add missing #include "qom/object.h" lines if necessary
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20200831210740.126168-9-ehabkost@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20200831210740.126168-10-ehabkost@redhat.com>
Message-Id: <20200831210740.126168-11-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
The existing type check macros all unconditionally drop const
qualifiers from their arguments. Keep this behavior in the
macros generated by DECLARE_*CHECKER* by now.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20200831210740.126168-6-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Sometimes the typedefs are buried inside another header, but
we want to benefit from the automatic definition of type cast
functions. Introduce macros that will let type checkers be
defined when typedefs are already available.
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20200831210740.126168-5-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Many QOM types don't follow the Type/TypeClass pattern
on the instance/struct names. Let the class struct name
be specified in the OBJECT_DECLARE* macros.
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20200831210740.126168-4-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
When creating new QOM types, there is a lot of boilerplate code that
must be repeated using a standard pattern. This is tedious to write
and liable to suffer from subtle inconsistencies. Thus it would
benefit from some simple automation.
QOM was loosely inspired by GLib's GObject, and indeed GObject suffers
from the same burden of boilerplate code, but has long provided a set of
macros to eliminate this burden in the source implementation. More
recently it has also provided a set of macros to eliminate this burden
in the header declaration.
In GLib there are the G_DECLARE_* and G_DEFINE_* family of macros
for the header declaration and source implementation respectively:
https://developer.gnome.org/gobject/stable/chapter-gobject.htmlhttps://developer.gnome.org/gobject/stable/howto-gobject.html
This patch takes inspiration from GObject to provide the equivalent
functionality for QOM.
In the header file, instead of:
typedef struct MyDevice MyDevice;
typedef struct MyDeviceClass MyDeviceClass;
G_DEFINE_AUTOPTR_CLEANUP_FUNC(MyDeviceClass, object_unref)
#define MY_DEVICE_GET_CLASS(void *obj) \
OBJECT_GET_CLASS(MyDeviceClass, obj, TYPE_MY_DEVICE)
#define MY_DEVICE_CLASS(void *klass) \
OBJECT_CLASS_CHECK(MyDeviceClass, klass, TYPE_MY_DEVICE)
#define MY_DEVICE(void *obj)
OBJECT_CHECK(MyDevice, obj, TYPE_MY_DEVICE)
struct MyDeviceClass {
DeviceClass parent_class;
};
We now have
OBJECT_DECLARE_SIMPLE_TYPE(MyDevice, my_device, MY_DEVICE, DEVICE)
In cases where the class needs some virtual methods, it can be left
to be implemented manually using
OBJECT_DECLARE_TYPE(MyDevice, my_device, MY_DEVICE)
Note that these macros are including support for g_autoptr() for the
object types, which is something previously only supported for variables
declared as the base Object * type.
Meanwhile in the source file, instead of:
static void my_device_finalize(Object *obj);
static void my_device_class_init(ObjectClass *oc, void *data);
static void my_device_init(Object *obj);
static const TypeInfo my_device_info = {
.parent = TYPE_DEVICE,
.name = TYPE_MY_DEVICE,
.instance_size = sizeof(MyDevice),
.instance_init = my_device_init,
.instance_finalize = my_device_finalize,
.class_size = sizeof(MyDeviceClass),
.class_init = my_device_class_init,
};
static void
my_device_register_types(void)
{
type_register_static(&my_device_info);
}
type_init(my_device_register_types);
We now have
OBJECT_DEFINE_TYPE(MyDevice, my_device, MY_DEVICE, DEVICE)
Or, if a class needs to implement interfaces:
OBJECT_DEFINE_TYPE_WITH_INTERFACES(MyDevice, my_device, MY_DEVICE, DEVICE,
{ TYPE_USER_CREATABLE }, { NULL })
Or, if a class needs to be abstract
OBJECT_DEFINE_ABSTRACT_TYPE(MyDevice, my_device, MY_DEVICE, DEVICE)
IOW, in both cases the maintainer now only has to think about the
interesting part of the code which implements useful functionality
and avoids much of the boilerplate.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200723181410.3145233-3-berrange@redhat.com>
[ehabkost: Fix G_DEFINE_AUTOPTR_CLEANUP_FUNC usage]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20200831210740.126168-3-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
The object_ref/unref methods are intended for use with any subclass of
the base Object. Using "Object *" in the signature is not adding any
meaningful level of type safety, since callers simply use "OBJECT(ptr)"
and this expands to an unchecked cast "(Object *)".
By using "void *" we enable the object_unref() method to be used to
provide support for g_autoptr() with any subclass.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200723181410.3145233-2-berrange@redhat.com>
Message-Id: <20200831210740.126168-2-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200714160202.3121879-5-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
object_get_canonical_path_component() returns a malloced copy of a
property name on success, null on failure.
19 of its 25 callers immediately free the returned copy.
Change object_get_canonical_path_component() to return the property
name directly. Since modifying the name would be wrong, adjust the
return type to const char *.
Drop the free from the 19 callers become simpler, add the g_strdup()
to the other six.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200714160202.3121879-4-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
object_property_add() does not allow object_property_try_add()
to gracefully fail as &error_abort is passed as an error handle.
However such failure can easily be triggered from the QMP shell when,
for instance, one attempts to create an object with an id that already
exists. This is achieved from the following call path:
qmp_object_add -> user_creatable_add_dict -> user_creatable_add_type ->
object_property_add_child -> object_property_add
For instance, from the qmp-shell, call twice:
object-add qom-type=memory-backend-ram id=mem1 props.size=1073741824
and QEMU aborts.
This behavior is undesired as a user/management application mistake
in reusing a property ID shouldn't result in loss of the VM and live
data within.
This patch introduces a new function, object_property_try_add_child()
which takes an error handle and turn object_property_try_add() into
a non-static one.
Now the call path becomes:
user_creatable_add_type -> object_property_try_add_child ->
object_property_try_add
and the error is returned gracefully to the QMP client.
(QEMU) object-add qom-type=memory-backend-ram id=mem2 props.size=4294967296
{"return": {}}
(QEMU) object-add qom-type=memory-backend-ram id=mem2 props.size=4294967296
{"error": {"class": "GenericError", "desc": "attempt to add duplicate property
'mem2' to object (type 'container')"}}
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Fixes: d2623129a7 ("qom: Drop parameter @errp of object_property_add() & friends")
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200629193424.30280-2-eric.auger@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Just for consistency. Also fix the example in object_set_props()'s
documentation.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-31-armbru@redhat.com>
See recent commit "error: Document Error API usage rules" for
rationale.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-28-armbru@redhat.com>
The object_property_set_FOO() setters take property name and value in
an unusual order:
void object_property_set_FOO(Object *obj, FOO_TYPE value,
const char *name, Error **errp)
Having to pass value before name feels grating. Swap them.
Same for object_property_set(), object_property_get(), and
object_property_parse().
Convert callers with this Coccinelle script:
@@
identifier fun = {
object_property_get, object_property_parse, object_property_set_str,
object_property_set_link, object_property_set_bool,
object_property_set_int, object_property_set_uint, object_property_set,
object_property_set_qobject
};
expression obj, v, name, errp;
@@
- fun(obj, v, name, errp)
+ fun(obj, name, v, errp)
Chokes on hw/arm/musicpal.c's lcd_refresh() with the unhelpful error
message "no position information". Convert that one manually.
Fails to convert hw/arm/armsse.c, because Coccinelle gets confused by
ARMSSE being used both as typedef and function-like macro there.
Convert manually.
Fails to convert hw/rx/rx-gdbsim.c, because Coccinelle gets confused
by RXCPU being used both as typedef and function-like macro there.
Convert manually. The other files using RXCPU that way don't need
conversion.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-27-armbru@redhat.com>
[Straightforwad conflict with commit 2336172d9b "audio: set default
value for pcspk.iobase property" resolved]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-22-armbru@redhat.com>
Little helper function to load modules on demand. In most cases adding
module loading support for devices and other objects is just
s/object_class_by_name/module_object_class_by_name/ in the right spot.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20200624131045.14512-3-kraxel@redhat.com
Suggested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200527084754.7531-2-armbru@redhat.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
We use the Object type all over the place.
Forward declare it in "qemu/typedefs.h".
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20200504115656.6045-2-f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Same story as for object_property_add(): the only way
object_property_del() can fail is when the property with this name
does not exist. Since our property names are all hardcoded, failure
is a programming error, and the appropriate way to handle it is
passing &error_abort. Most callers do that, the commit before
previous fixed one that didn't (and got the error handling wrong), and
the two remaining exceptions ignore errors.
Drop the @errp parameter.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-19-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
The only way object_property_add() can fail is when a property with
the same name already exists. Since our property names are all
hardcoded, failure is a programming error, and the appropriate way to
handle it is passing &error_abort.
Same for its variants, except for object_property_add_child(), which
additionally fails when the child already has a parent. Parentage is
also under program control, so this is a programming error, too.
We have a bit over 500 callers. Almost half of them pass
&error_abort, slightly fewer ignore errors, one test case handles
errors, and the remaining few callers pass them to their own callers.
The previous few commits demonstrated once again that ignoring
programming errors is a bad idea.
Of the few ones that pass on errors, several violate the Error API.
The Error ** argument must be NULL, &error_abort, &error_fatal, or a
pointer to a variable containing NULL. Passing an argument of the
latter kind twice without clearing it in between is wrong: if the
first call sets an error, it no longer points to NULL for the second
call. ich9_pm_add_properties(), sparc32_ledma_realize(),
sparc32_dma_realize(), xilinx_axidma_realize(), xilinx_enet_realize()
are wrong that way.
When the one appropriate choice of argument is &error_abort, letting
users pick the argument is a bad idea.
Drop parameter @errp and assert the preconditions instead.
There's one exception to "duplicate property name is a programming
error": the way object_property_add() implements the magic (and
undocumented) "automatic arrayification". Don't drop @errp there.
Instead, rename object_property_add() to object_property_try_add(),
and add the obvious wrapper object_property_add().
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-15-armbru@redhat.com>
[Two semantic rebase conflicts resolved]
object_property_set_description() and
object_class_property_set_description() fail only when property @name
is not found.
There are 85 calls of object_property_set_description() and
object_class_property_set_description(). None of them can fail:
* 84 immediately follow the creation of the property.
* The one in spapr_rng_instance_init() refers to a property created in
spapr_rng_class_init(), from spapr_rng_properties[].
Every one of them still gets to decide what to pass for @errp.
51 calls pass &error_abort, 32 calls pass NULL, one receives the error
and propagates it to &error_abort, and one propagates it to
&error_fatal. I'm actually surprised none of them violates the Error
API.
What are we gaining by letting callers handle the "property not found"
error? Use when the property is not known to exist is simpler: you
don't have to guard the call with a check. We haven't found such a
use in 5+ years. Until we do, let's make life a bit simpler and drop
the @errp parameter.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-8-armbru@redhat.com>
[One semantic rebase conflict resolved]
Some object_property_add_FOO() return the newly added property, some
don't. Clean that up.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-7-armbru@redhat.com>
qom/object.c provides object_property_get_TYPE() and
object_property_set_TYPE() for a number of common types. These are
all convenience wrappers around object_property_get_qobject() and
object_property_set_qobject().
Except for object_property_get_uint16List(), which is unusual in two ways:
* It bypasses object_property_get_qobject(). Fixable; the previous
commit did it for object_property_get_enum())
* It stores the value through a parameter. Its contract claims it
returns the value, like the other functions do. Also fixable.
Fixing is not worthwhile, though: object_property_get_uint16List() has
seen exactly one user in six years.
Convert the lone user to do its job with the generic
object_property_get_qobject(), and drop object_property_get_uint16List().
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200505152926.18877-6-armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
[Commit message typo fixed]
Uses of gchar * in qom/object.h:
* ObjectProperty member @name
Functions that take a property name argument all use char *. Change
the member to match.
* ObjectProperty member @type
Functions that take a property type argument or return it all use
char *. Change the member to match.
* ObjectProperty member @description
Functions that take a property description argument all use char *.
Change the member to match.
* object_resolve_path_component() parameter @part
Path components are property names. Most callers pass char *
arguments. Change the parameter to match. Adjust the few callers
that pass gchar * to pass char *.
* Return value of object_get_canonical_path_component(),
object_get_canonical_path()
Most callers convert their return values right back to char *.
Change the return value to match. Adjust the few callers where that
would add a conversion to gchar * to use char * instead.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-3-armbru@redhat.com>
After processing the option string with the keyval parser, we get a
QDict that contains only strings. This QDict must be fed to a keyval
visitor which converts the strings into the right data types.
qmp_object_add(), however, uses the normal QObject input visitor, which
expects a QDict where all properties already have the QType that matches
the data type required by the QOM object type.
Change the --object implementation in qemu-storage-daemon so that it
doesn't call qmp_object_add(), but calls user_creatable_add_dict()
directly instead and pass it a new keyval boolean that decides which
visitor must be used.
Reported-by: Coiby Xu <coiby.xu@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The QMP handler qmp_object_add() and the implementation of --object in
qemu-storage-daemon can share most of the code. Currently,
qemu-storage-daemon calls qmp_object_add(), but this is not correct
because different visitors need to be used.
As a first step towards a fix, make qmp_object_add() a wrapper around a
new function user_creatable_add_dict() that can get an additional
parameter. The handling of "props" is only required for compatibility
and not required for the qemu-storage-daemon command line, so it stays
in qmp_object_add().
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Traditionally, the uint-specific property helpers only offer getters.
When adding object (or class) uint types, one must therefore use the
generic property helper if a setter is needed (and probably duplicate
some code writing their own getters/setters).
This enhances the uint-specific property helper APIs by adding a
bitwise-or'd 'flags' field and modifying all clients of that API to set
this paramater to OBJ_PROP_FLAG_READ. This maintains the current
behaviour whilst allowing others to also set OBJ_PROP_FLAG_WRITE (or use
the more convenient OBJ_PROP_FLAG_READWRITE) in the future (which will
automatically install a setter). Other flags may be added later.
Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Mapping object-add to the command line as is doesn't result in nice
syntax because of the nesting introduced with 'props'. This becomes
nicer and more consistent with device_add and netdev_add when we accept
properties for the object on the top level instead.
'props' is still accepted after this patch, but marked as deprecated.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200224143008.13362-8-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Let's factor out the code to format a help string for a property. We
are going to reuse it in qdev next, which will bring some consistency.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-25-marcandre.lureau@redhat.com>
[Adjust for removal of object_property_get_default, move default
after description. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This allow for simpler assignment with ref: foo = object_ref(bar)
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200110153039.1379601-19-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Allow the link property to hold the pointer to the target, instead of
indirectly through another variable.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-15-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
A child property is a different kind of property. Let's use "target"
for the link target.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-14-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a default value to ObjectProperty and an implementation of
ObjectPropertyInit that uses it. This will make it easier to show the
default in help messages.
Also provide convenience functions object_property_set_default_{bool,
str, int, uint}().
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-11-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This will help calling other ObjectProperty associated functions
easily after.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-9-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This callback is used to set default value in following patch "object:
add object_property_set_defaut_{bool,str,int,uint}()".
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-7-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20191205174635.18758-19-vsementsov@virtuozzo.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
QOM interfaces allow a limited form of multiple inheritance, at the
condition of being stateless. That is, they cannot be instantiated
and a pointer to an interface shouldn't be dereferenceable in any way.
This is achieved by making the QOM instance type an incomplete type,
which is, as mentioned by Markus Armbruster, the closest you can get
to abstract class in C.
Incomplete types are widely used to hide implementation details, but
people usually expect to find at least one place where the type is
fully defined. The fact that it doesn't happen with QOM interfaces is
quite disturbing, especially since it isn't documented anywhere as
recently discussed in this thread:
https://lists.gnu.org/archive/html/qemu-devel/2019-12/msg01579.html
Amend the documentation in the object.h header file to provide more
details about why and how to implement QOM interfaces using incomplete
types.
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Similar to CPU and machine classes, "-accel" class names are mangled,
so we have to first get a class via accel_find and then instantiate it.
Provide a new function to instantiate a class without going through
object_class_get_name, and use it for CPUs and machines already.
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Similar to the existing "-rtc driftfix" option, we will convert some
legacy "-machine" command line options to global properties on accelerators.
Because accelerators are not devices, we cannot use qdev_prop_register_global.
Instead, provide a slot in the generic object_compat_props arrays for
command line syntactic sugar.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Printing help for --object is something that we not only want in the
system emulator, but also in tools that support --object. Move it into a
separate function in qom/object_interfaces.c to make the code accessible
for tools.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190709152053.16670-2-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[Rebased onto merge commit 95a9457fd44; missed instances of qom/cpu.h
in comments replaced]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-20-armbru@redhat.com>
We declare incomplete struct VMStateDescription in a couple of places
so we don't have to include migration/vmstate.h for the typedef.
That's fine with me. However, the next commit will drop
migration/vmstate.h from a massive number of compiles. Move the
typedef to qemu/typedefs.h now, so I don't have to insert struct in
front of VMStateDescription all over the place then.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-15-armbru@redhat.com>
Amusingly, we had already ignored the comment to keep this value
at the end of CPUState. This restores the minimum negative offset
from TCG_AREG0 for code generation.
For the couple of uses within qom/cpu.c, without NEED_CPU_H, add
a pointer from the CPUState object to the IcountDecr object within
CPUNegativeOffsetState.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
