Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2021-10-29' into staging

QAPI patches patches for 2021-10-29

# gpg: Signature made Fri 29 Oct 2021 12:28:53 PM PDT
# gpg:

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2021-10-29' into staging

QAPI patches patches for 2021-10-29

# gpg: Signature made Fri 29 Oct 2021 12:28:53 PM PDT
# gpg: using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653
# gpg: issuer "armbru@redhat.com"
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>" [full]

* remotes/armbru/tags/pull-qapi-2021-10-29:
qapi: Extend -compat to set policy for unstable interfaces
qapi: Factor out compat_policy_input_ok()
qapi: Generalize enum member policy checking
qapi: Generalize command policy checking
qapi: Generalize struct member policy checking
qapi: Tools for sets of special feature flags in generated code
qapi: Eliminate QCO_NO_OPTIONS for a slight simplification
qapi: Mark unstable QMP parts with feature 'unstable'
qapi: New special feature flag "unstable"

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

show more ...

qapi: Generalize struct member policy checking

The generated visitor functions call visit_deprecated_accept() and
visit_deprecated() when visiting a struct member with special feature
flag 'deprecat

qapi: Generalize struct member policy checking

The generated visitor functions call visit_deprecated_accept() and
visit_deprecated() when visiting a struct member with special feature
flag 'deprecated'. This makes the feature flag visible to the actual
visitors. I want to make feature flag 'unstable' visible there as
well, so I can add policy for it.

To let me make it visible, replace these functions by
visit_policy_reject() and visit_policy_skip(), which take the member's
special features as an argument. Note that the new functions have the
opposite sense, i.e. the return value flips.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20211028102520.747396-6-armbru@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[Unbreak forward visitor]

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2021-10-27' into staging

QAPI patches patches for 2021-10-27

# gpg: Signature made Wed 27 Oct 2021 08:21:54 AM PDT
# gpg:

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2021-10-27' into staging

QAPI patches patches for 2021-10-27

# gpg: Signature made Wed 27 Oct 2021 08:21:54 AM PDT
# gpg: using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653
# gpg: issuer "armbru@redhat.com"
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>" [full]

* remotes/armbru/tags/pull-qapi-2021-10-27:
qapi: Implement deprecated-input={reject,crash} for enum values
qapi: Move compat policy from QObject to generic visitor
qapi: Add feature flags to enum members
qapi: Enable enum member introspection to show more than name
qapi: Improve input_type_enum()'s error message

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

show more ...

qapi: Move compat policy from QObject to generic visitor

The next commit needs to access compat policy from the generic visitor
core. Move it there from qobject input and output visitor.

Signed-of

qapi: Move compat policy from QObject to generic visitor

The next commit needs to access compat policy from the generic visitor
core. Move it there from qobject input and output visitor.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20211025042405.3762351-4-armbru@redhat.com>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2021-03-16-v4' into staging

QAPI patches patches for 2021-03-16

# gpg: Signature made Fri 19 Mar 2021 15:06:52 GMT
# gpg:

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2021-03-16-v4' into staging

QAPI patches patches for 2021-03-16

# gpg: Signature made Fri 19 Mar 2021 15:06:52 GMT
# gpg: using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653
# gpg: issuer "armbru@redhat.com"
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>" [full]
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-qapi-2021-03-16-v4:
qapi: New -compat deprecated-input=crash
qapi: Implement deprecated-input=reject for QMP command arguments
qapi: Implement deprecated-input=reject for QMP commands
test-util-sockets: Add stub for monitor_set_cur()
qapi: Implement deprecated-output=hide for QMP introspection
monitor: Drop query-qmp-schema 'gen': false hack
qapi: Implement deprecated-output=hide for QMP event data
qapi: Implement deprecated-output=hide for QMP events
qapi: Implement deprecated-output=hide for QMP command results
qemu-options: New -compat to set policy for deprecated interfaces
qemuutil: remove qemu_set_fd_handler duplicate symbol

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

qapi: Implement deprecated-input=reject for QMP command arguments

This policy rejects deprecated input, and thus permits "testing the
future". Implement it for QMP command arguments: reject command

qapi: Implement deprecated-input=reject for QMP command arguments

This policy rejects deprecated input, and thus permits "testing the
future". Implement it for QMP command arguments: reject commands with
deprecated ones. Example: when QEMU is run with -compat
deprecated-input=reject, then

{"execute": "eject", "arguments": {"device": "cd"}}

fails like this

{"error": {"class": "GenericError", "desc": "Deprecated parameter 'device' disabled by policy"}}

When the deprecated parameter is removed, the error will change to

{"error": {"class": "GenericError", "desc": "Parameter 'device' is unexpected"}}

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210318155519.1224118-11-armbru@redhat.com>

show more ...

qapi: Implement deprecated-output=hide for QMP command results

This policy suppresses deprecated bits in output, and thus permits
"testing the future". Implement it for QMP command results. Exampl

qapi: Implement deprecated-output=hide for QMP command results

This policy suppresses deprecated bits in output, and thus permits
"testing the future". Implement it for QMP command results. Example:
when QEMU is run with -compat deprecated-output=hide, then

{"execute": "query-cpus-fast"}

yields

{"return": [{"thread-id": 9805, "props": {"core-id": 0, "thread-id": 0, "socket-id": 0}, "qom-path": "/machine/unattached/device[0]", "cpu-index": 0, "target": "x86_64"}]}

instead of

{"return": [{"arch": "x86", "thread-id": 22436, "props": {"core-id": 0, "thread-id": 0, "socket-id": 0}, "qom-path": "/machine/unattached/device[0]", "cpu-index": 0, "target": "x86_64"}]}

Note the suppression of deprecated member "arch".

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210318155519.1224118-4-armbru@redhat.com>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-error-2020-07-07-v2' into staging

Error reporting patches patches for 2020-07-07

# gpg: Signature made Fri 10 Jul 2020 14:24:42 BST
# gpg:

Merge remote-tracking branch 'remotes/armbru/tags/pull-error-2020-07-07-v2' into staging

Error reporting patches patches for 2020-07-07

# gpg: Signature made Fri 10 Jul 2020 14:24:42 BST
# gpg: using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653
# gpg: issuer "armbru@redhat.com"
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>" [full]
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-error-2020-07-07-v2: (53 commits)
xen: Use ERRP_GUARD()
nbd: Use ERRP_GUARD()
virtio-9p: Use ERRP_GUARD()
fw_cfg: Use ERRP_GUARD()
pflash: Use ERRP_GUARD()
sd: Use ERRP_GUARD()
scripts: Coccinelle script to use ERRP_GUARD()
error: New macro ERRP_GUARD()
hmp: Ignore Error objects where the return value suffices
qdev: Ignore Error objects where the return value suffices
qemu-img: Ignore Error objects where the return value suffices
error: Avoid error_propagate() after migrate_add_blocker()
qapi: Purge error_propagate() from QAPI core
qapi: Smooth visitor error checking in generated code
qapi: Smooth another visitor error checking pattern
block/parallels: Simplify parallels_open() after previous commit
error: Reduce unnecessary error propagation
error: Eliminate error_propagate() manually
error: Eliminate error_propagate() with Coccinelle, part 2
error: Eliminate error_propagate() with Coccinelle, part 1
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

qapi: Make visitor functions taking Error ** return bool, not void

See recent commit "error: Document Error API usage rules" for
rationale.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Revi

qapi: Make visitor functions taking Error ** return bool, not void

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: <20200707160613.848843-18-armbru@redhat.com>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2020-04-30' into staging

QAPI patches for 2020-04-30

# gpg: Signature made Thu 30 Apr 2020 06:29:18 BST
# gpg: using RSA k

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2020-04-30' into staging

QAPI patches for 2020-04-30

# gpg: Signature made Thu 30 Apr 2020 06:29:18 BST
# gpg: using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653
# gpg: issuer "armbru@redhat.com"
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>" [full]
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-qapi-2020-04-30:
qapi: Generate simpler marshalling code when no arguments
qapi: Disallow qmp_marshal_FOO(NULL, ...)
qom: Simplify object_property_get_enum()
qapi: Only input visitors can actually fail
qapi: Assert non-input visitors see only valid alternate tags
qapi: Clean up visitor's recovery from input with invalid type
qapi: Assert non-input visitors see only valid narrow integers
qapi: Assert output visitors see only valid enum values
qapi: Fix Visitor contract for start_alternate()
qapi: Assert incomplete object occurs only in dealloc visitor
qapi: Polish prose in visitor.h
qapi: Document @errp usage more thoroughly in visitor.h
qapi: Fix typo in visit_start_list()'s contract
qapi: Fix the virtual walk example in visitor.h's big comment
qapi: Belatedly update visitor.h's big comment for QAPI modules
qemu-option: Clean up after the previous commit
qobject: Eliminate qdict_iter(), use qdict_first(), qdict_next()
qobject: Eliminate qlist_iter(), use QLIST_FOREACH_ENTRY() instead
qobject: Factor out helper json_pretty_newline()
qobject: Clean up QLIST_FOREACH_ENTRY()

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

qapi: Only input visitors can actually fail

The previous few commits have made this more obvious, and removed the
one exception. Time to clarify the documentation, and drop dead error
checking.

Si

qapi: Only input visitors can actually fail

The previous few commits have made this more obvious, and removed the
one exception. Time to clarify the documentation, and drop dead error
checking.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-13-armbru@redhat.com>

show more ...

qapi: Fix Visitor contract for start_alternate()

The contract demands v->start_alternate() for input and dealloc
visitors, but visit_start_alternate() actually requires it for input
and clone visito

qapi: Fix Visitor contract for start_alternate()

The contract demands v->start_alternate() for input and dealloc
visitors, but visit_start_alternate() actually requires it for input
and clone visitors. Fix the contract, and delete superfluous
qapi_dealloc_start_alternate().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-8-armbru@redhat.com>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2017-07-18-v2' into staging

QAPI patches for 2017-07-18

# gpg: Signature made Mon 24 Jul 2017 12:40:56 BST
# gpg: using RS

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2017-07-18-v2' into staging

QAPI patches for 2017-07-18

# gpg: Signature made Mon 24 Jul 2017 12:40:56 BST
# gpg: using RSA key 0x3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-qapi-2017-07-18-v2:
migration: Use JSON null instead of "" to reset parameter to default
migration: Unshare MigrationParameters struct for now
migration: Add TODO comments on duplication of QAPI_CLONE()
migration: Clean up around tls_creds, tls_hostname
hmp: Clean up and simplify hmp_migrate_set_parameter()
block: Use JSON null instead of "" to disable backing file
tests/test-qobject-input-visitor: Drop redundant test
qapi: Introduce a first class 'null' type
qapi: Use QNull for a more regular visit_type_null()
qapi: Separate type QNull from QObject

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

qapi: Use QNull for a more regular visit_type_null()

Make visit_type_null() take an @obj argument like its buddies. This
helps keep the next commit simple.

Signed-off-by: Markus Armbruster <armbru

qapi: Use QNull for a more regular visit_type_null()

Make visit_type_null() take an @obj argument like its buddies. This
helps keep the next commit simple.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2017-06-09-v2' into staging

QAPI patches for 2017-06-09

# gpg: Signature made Tue 20 Jun 2017 13:31:39 BST
# gpg: using RS

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2017-06-09-v2' into staging

QAPI patches for 2017-06-09

# gpg: Signature made Tue 20 Jun 2017 13:31:39 BST
# gpg: using RSA key 0x3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-qapi-2017-06-09-v2: (41 commits)
tests/qdict: check more get_try_int() cases
console: use get_uint() for "head" property
i386/cpu: use get_uint() for "min-level"/"min-xlevel" properties
numa: use get_uint() for "size" property
pnv-core: use get_uint() for "core-pir" property
pvpanic: use get_uint() for "ioport" property
auxbus: use get_uint() for "addr" property
arm: use get_uint() for "mp-affinity" property
xen: use get_uint() for "max-ram-below-4g" property
pc: use get_uint() for "hpet-intcap" property
pc: use get_uint() for "apic-id" property
pc: use get_uint() for "iobase" property
acpi: use get_uint() for "pci-hole*" properties
acpi: use get_uint() for various acpi properties
acpi: use get_uint() for "acpi-pcihp-io*" properties
platform-bus: use get_uint() for "addr" property
bcm2835_fb: use {get, set}_uint() for "vcram-size" and "vcram-base"
aspeed: use {set, get}_uint() for "ram-size" property
pcihp: use get_uint() for "bsel" property
pc-dimm: make "size" property uint64
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

qapi: Remove visit_start_alternate() parameter promote_int

Before the previous commit, parameter promote_int = true made
visit_start_alternate() with an input visitor avoid QTYPE_QINT
variants and c

qapi: Remove visit_start_alternate() parameter promote_int

Before the previous commit, parameter promote_int = true made
visit_start_alternate() with an input visitor avoid QTYPE_QINT
variants and create QTYPE_QFLOAT variants instead. This was used
where QTYPE_QINT variants were invalid.

The previous commit fused QTYPE_QINT with QTYPE_QFLOAT, rendering
promote_int useless and unused.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20170607163635.17635-8-marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

Merge remote-tracking branch 'clg/aspeed'

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2017-02-28' into staging

QAPI patches for 2017-02-28

# gpg: Signature made Sun 05 Mar 2017 08:21:51 GMT
# gpg: using RSA k

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2017-02-28' into staging

QAPI patches for 2017-02-28

# gpg: Signature made Sun 05 Mar 2017 08:21:51 GMT
# gpg: using RSA key 0x3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-qapi-2017-02-28: (27 commits)
qapi: Improve qobject visitor documentation
qapi: Fix object input visit beyond end of list
tests: Cover input visit beyond end of list
qapi: Make input visitors detect unvisited list tails
test-qobject-input-visitor: Cover missing nested struct member
tests: Cover partial input visit of list
test-string-input-visitor: Improve list coverage
test-string-input-visitor: Tear down existing test automatically
tests-qobject-input-strict: Merge into test-qobject-input-visitor
qapi: Drop unused non-strict qobject input visitor
test-qobject-input-visitor: Use strict visitor
qom: Make object_property_set_qobject()'s input visitor strict
qapi: Make string input and opts visitor require non-null input
qapi: Drop string input visitor method optional()
qapi: Improve qobject input visitor error reporting
qapi: Make QObject input visitor set *list reliably
qapi: Clean up after commit 3d344c2
qapi: Improve a QObject input visitor error message
qmp: Eliminate silly QERR_QMP_* macros
qmp: Drop duplicated QMP command object checks
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

qapi: Make input visitors detect unvisited list tails

Fix the design flaw demonstrated in the previous commit: new method
check_list() lets input visitors report that unvisited input remains
for a l

qapi: Make input visitors detect unvisited list tails

Fix the design flaw demonstrated in the previous commit: new method
check_list() lets input visitors report that unvisited input remains
for a list, exactly like check_struct() lets them report that
unvisited input remains for a struct or union.

Implement the method for the qobject input visitor (straightforward),
and the string input visitor (less so, due to the magic list syntax
there). The opts visitor's list magic is even more impenetrable, and
all I can do there today is a stub with a FIXME comment. No worse
than before.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1488544368-30622-26-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

show more ...

qapi: Drop string input visitor method optional()

visit_optional() is to be called only between visit_start_struct() and
visit_end_struct(). Visitors that don't support struct visits,
i.e. don't im

qapi: Drop string input visitor method optional()

visit_optional() is to be called only between visit_start_struct() and
visit_end_struct(). Visitors that don't support struct visits,
i.e. don't implement start_struct(), end_struct(), have no use for it.
Clarify documentation.

The string input visitor doesn't support struct visits. Its
parse_optional() is therefore useless. Drop it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1488544368-30622-16-git-send-email-armbru@redhat.com>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2016-07-06' into staging

QAPI patches for 2016-07-06

# gpg: Signature made Wed 06 Jul 2016 10:00:51 BST
# gpg: using RSA k

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2016-07-06' into staging

QAPI patches for 2016-07-06

# gpg: Signature made Wed 06 Jul 2016 10:00:51 BST
# gpg: using RSA key 0x3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-qapi-2016-07-06:
replay: Use new QAPI cloning
sockets: Use new QAPI cloning
qapi: Add new clone visitor
qapi: Add new visit_complete() function
tests: Factor out common code in qapi output tests
tests: Clean up test-string-output-visitor
qmp-output-visitor: Favor new visit_free() function
string-output-visitor: Favor new visit_free() function
qmp-input-visitor: Favor new visit_free() function
string-input-visitor: Favor new visit_free() function
opts-visitor: Favor new visit_free() function
qapi: Add new visit_free() function
qapi: Add parameter to visit_end_*
qemu-img: Don't leak errors when outputting JSON
qapi: Improve use of qmp/types.h

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

qapi: Add new clone visitor

We have a couple places in the code base that want to deep-clone
one QAPI object into another, and they were resorting to serializing
the struct out to QObject then repar

qapi: Add new clone visitor

We have a couple places in the code base that want to deep-clone
one QAPI object into another, and they were resorting to serializing
the struct out to QObject then reparsing it. A much more efficient
version can be done by adding a new clone visitor.

Since cloning is still relatively uncommon, expose the use of the
new visitor via a QAPI_CLONE() macro that takes care of type-punning
the underlying function pointer, rather than generating lots of
unused functions for types that won't be cloned. And yes, we're
relying on the compiler treating all pointers equally, even though
a strict C program cannot portably do so - but we're not the first
one in the qemu code base to expect it to work (hello, glib!).

The choice of adding a fourth visitor type deserves some explanation.
On the surface, the clone visitor is mostly an input visitor (it
takes arbitrary input - in this case, another QAPI object - and
creates a new QAPI object during the course of the visit). But
ever since commit da72ab0 consolidated enum visits based on the
visitor type, using VISITOR_INPUT would cause us to run
visit_type_str(), even though for cloning there is nothing to do
(we just copy the enum value across, without regards to its mapping
to strings). Also, since our input happens to be a QAPI object,
we can also satisfy the internal checks for VISITOR_OUTPUT. So in
the end, I settled with a new VISITOR_CLONE, and chose its value
such that many internal checks can use 'v->type & mask', sticking
to 'v->type == value' where the difference matters.

Note that we can only clone objects (including alternates) and lists,
not built-ins or enums. The visitor core hides integer width from
the actual visitor (since commit 04e070d), and as long as that's the
case, we can't clone top-level integers. Then again, those can
always be cloned by direct copy, since they are not objects with
deep pointers, so it's no real loss. And restricting cloning to
just objects and lists is cleaner than restricting it to non-integers.
As such, I documented that the clone visitor is for direct use only
by code internal to QAPI, and should not be used on incomplete objects
(other than a hack to work around the fact that we allow NULL in place
of "" in visit_type_str() in other output visitors). Note that as
written, the clone visitor will never fail on a complete object.

Scalars (including enums) not at the root of the clone copy just fine
with no additional effort while visiting the scalar, by virtue of a
g_memdup() each time we push another struct onto the stack. Cloning
a string requires deduplication of a pointer, which means it can also
provide the guarantee of an input visitor of never producing NULL
even when still accepting NULL in place of "" the way the QMP output
visitor does.

Cloning an 'any' type could be possible by incrementing the QObject
refcnt, but it's not obvious whether that is better than implementing
a QObject deep clone. So for now, we document it as unsupported,
and intentionally omit the .type_any() callback to let a developer
know their usage needs implementation.

Add testsuite coverage for several different clone situations, to
ensure that the code is working. I also tested that valgrind was
happy with the test.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-14-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

qapi: Add new visit_complete() function

Making each output visitor provide its own output collection
function was the only remaining reason for exposing visitor
sub-types to the rest of the code bas

qapi: Add new visit_complete() function

Making each output visitor provide its own output collection
function was the only remaining reason for exposing visitor
sub-types to the rest of the code base. Add a polymorphic
visit_complete() function which is a no-op for input visitors,
and which populates an opaque pointer for output visitors. For
maximum type-safety, also add a parameter to the output visitor
constructors with a type-correct version of the output pointer,
and assert that the two uses match.

This approach was considered superior to either passing the
output parameter only during construction (action at a distance
during visit_free() feels awkward) or only during visit_complete()
(defeating type safety makes it easier to use incorrectly).

Most callers were function-local, and therefore a mechanical
conversion; the testsuite was a bit trickier, but the previous
cleanup patch minimized the churn here.

The visit_complete() function may be called at most once; doing
so lets us use transfer semantics rather than duplication or
ref-count semantics to get the just-built output back to the
caller, even though it means our behavior is not idempotent.

Generated code is simplified as follows for events:

|@@ -26,7 +26,7 @@ void qapi_event_send_acpi_device_ost(ACP
| QDict *qmp;
| Error *err = NULL;
| QMPEventFuncEmit emit;
|- QmpOutputVisitor *qov;
|+ QObject *obj;
| Visitor *v;
| q_obj_ACPI_DEVICE_OST_arg param = {
| info
|@@ -39,8 +39,7 @@ void qapi_event_send_acpi_device_ost(ACP
|
| qmp = qmp_event_build_dict("ACPI_DEVICE_OST");
|
|- qov = qmp_output_visitor_new();
|- v = qmp_output_get_visitor(qov);
|+ v = qmp_output_visitor_new(&obj);
|
| visit_start_struct(v, "ACPI_DEVICE_OST", NULL, 0, &err);
| if (err) {
|@@ -55,7 +54,8 @@ void qapi_event_send_acpi_device_ost(ACP
| goto out;
| }
|
|- qdict_put_obj(qmp, "data", qmp_output_get_qobject(qov));
|+ visit_complete(v, &obj);
|+ qdict_put_obj(qmp, "data", obj);
| emit(QAPI_EVENT_ACPI_DEVICE_OST, qmp, &err);

and for commands:

| {
| Error *err = NULL;
|- QmpOutputVisitor *qov = qmp_output_visitor_new();
| Visitor *v;
|
|- v = qmp_output_get_visitor(qov);
|+ v = qmp_output_visitor_new(ret_out);
| visit_type_AddfdInfo(v, "unused", &ret_in, &err);
|- if (err) {
|- goto out;
|+ if (!err) {
|+ visit_complete(v, ret_out);
| }
|- *ret_out = qmp_output_get_qobject(qov);
|-
|-out:
| error_propagate(errp, err);

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-13-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

qapi: Add new visit_free() function

Making each visitor provide its own (awkwardly-named) FOO_cleanup()
is unusual, when we can instead have a polymorphic visit_free()
interface. Over the next few

qapi: Add new visit_free() function

Making each visitor provide its own (awkwardly-named) FOO_cleanup()
is unusual, when we can instead have a polymorphic visit_free()
interface. Over the next few patches, we can use the polymorphic
functions to eliminate the need for a FOO_get_visitor() function
for accessing specific visitor functionality, once everything can
be accessed directly through the Visitor* interfaces.

The dealloc visitor is the first one converted to completely use
the new entry point, since qapi_dealloc_visitor_cleanup() was the
only reason that qapi_dealloc_get_visitor() existed, and only
generated and testsuite code was even using it. With the new
visit_free() entry point in place, we no longer need to expose
the QapiDeallocVisitor subtype through qapi_dealloc_visitor_new(),
and can get by with less generated code, with diffs that look like:

| void qapi_free_ACPIOSTInfo(ACPIOSTInfo *obj)
| {
|- QapiDeallocVisitor *qdv;
| Visitor *v;
|
| if (!obj) {
| return;
| }
|
|- qdv = qapi_dealloc_visitor_new();
|- v = qapi_dealloc_get_visitor(qdv);
|+ v = qapi_dealloc_visitor_new();
| visit_type_ACPIOSTInfo(v, NULL, &obj, NULL);
|- qapi_dealloc_visitor_cleanup(qdv);
|+ visit_free(v);
|}

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-5-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

qapi: Add parameter to visit_end_*

Rather than making the dealloc visitor track of stack of pointers
remembered during visit_start_* in order to free them during
visit_end_*, it's a lot easier to ju

qapi: Add parameter to visit_end_*

Rather than making the dealloc visitor track of stack of pointers
remembered during visit_start_* in order to free them during
visit_end_*, it's a lot easier to just make all callers pass the
same pointer to visit_end_*. The generated code has access to the
same pointer, while all other users are doing virtual walks and
can pass NULL. The dealloc visitor is then greatly simplified.

All three visit_end_*() functions intentionally take a void**,
even though the visit_start_*() functions differ between void**,
GenericList**, and GenericAlternate**. This is done for several
reasons: when doing a virtual walk, passing NULL doesn't care
what the type is, but when doing a generated walk, we already
have to cast the caller's specific FOO* to call visit_start,
while using void** lets us use visit_end without a cast. Also,
an upcoming patch will add a clone visitor that wants to use
the same implementation for all three visit_end callbacks,
which is made easier if all three share the same signature.

For visitors with already track per-object state (the QMP visitors
via a stack, and the string visitors which do not allow nesting),
add an assertion that the caller is indeed passing the same
pointer to paired calls.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-4-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...