Commit Graph

303 Commits

Author SHA1 Message Date
Markus Armbruster
8339fa266c qapi: Document visit_type_any() issues with keyval input
It's already documented in keyval.c (commit 0ee9ae7), but visitor.h
can use a note, too.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1495471335-23707-3-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2017-05-31 16:04:05 +02:00
Markus Armbruster
ed0ba0f47e qapi: Document intended use of @name within alternate visits
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1493282486-28338-4-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2017-05-09 09:14:40 +02:00
Markus Armbruster
4626a19c86 qapi: New QAPI_CLONE_MEMBERS()
QAPI_CLONE() returns a newly allocated QAPI object.  Inconvenient when
we want to clone into an existing object.  QAPI_CLONE_MEMBERS() does
exactly that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1493192202-3184-4-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-05-09 09:14:40 +02:00
Eric Blake
a92c21591b qobject: Add helper macros for common scalar insertions
Rather than making lots of callers wrap a scalar in a QInt, QString,
or QBool, provide helper macros that do the wrapping automatically.

Update the Coccinelle script to make mass conversions easy, although
the conversion itself will be done as a separate patches to ease
review and backport efforts.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20170427215821.19397-6-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-05-08 20:32:14 +02:00
Markus Armbruster
9d1eab4b95 qapi: New qobject_input_visitor_new_str() for convenience
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1488317230-26248-21-git-send-email-armbru@redhat.com>
2017-03-07 16:07:47 +01:00
Markus Armbruster
069b64e3fe qapi: New parse_qapi_name()
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1488317230-26248-19-git-send-email-armbru@redhat.com>
2017-03-07 16:07:47 +01:00
Markus Armbruster
57348c2f18 qobject: Propagate parse errors through qobject_from_json()
The next few commits will put the errors to use where appropriate.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1488317230-26248-13-git-send-email-armbru@redhat.com>
2017-03-07 16:07:47 +01:00
Markus Armbruster
99dbfd1db1 qobject: Propagate parse errors through qobject_from_jsonv()
The next few commits will put the errors to use where appropriate.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <1488317230-26248-9-git-send-email-armbru@redhat.com>
2017-03-07 16:07:47 +01:00
Daniel P. Berrange
cbd8acf38f qapi: qobject input visitor variant for use with keyval_parse()
Currently the QObjectInputVisitor assumes that all scalar values are
directly represented as the final types declared by the thing being
visited. i.e. it assumes an 'int' is using QInt, and a 'bool' is using
QBool, etc.  This is good when QObjectInputVisitor is fed a QObject
that came from a JSON document on the QMP monitor, as it will strictly
validate correctness.

To allow QObjectInputVisitor to be reused for visiting a QObject
originating from keyval_parse(), an alternative mode is needed where
all the scalars types are represented as QString and converted on the
fly to the final desired type.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1475246744-29302-8-git-send-email-berrange@redhat.com>

Rebased, conflicts resolved, commit message updated to refer to
keyval_parse().  autocast replaced by keyval in identifiers,
noautocast replaced by fail in tests.

Fix qobject_input_type_uint64_keyval() not to reject '-', for QemuOpts
compatibility: replace parse_uint_full() by open-coded
parse_option_number().  The next commit will add suitable tests.
Leave out the fancy ERANGE error reporting for now, but add a TODO
comment.  Add it qobject_input_type_int64_keyval() and
qobject_input_type_number_keyval(), too.

Open code parse_option_bool() and parse_option_size() so we have to
call qobject_input_get_name() only when actually needed.  Again, leave
out ERANGE error reporting for now.

QAPI/QMP downstream extension prefixes __RFQDN_ don't work, because
keyval_parse() splits them at '.'.  This will be addressed later in
the series.

qobject_input_type_int64_keyval(), qobject_input_type_uint64_keyval(),
qobject_input_type_number_keyval() tweaked for style.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <1488317230-26248-5-git-send-email-armbru@redhat.com>
2017-03-07 16:07:46 +01:00
Markus Armbruster
aa3a982e67 qapi: Improve qobject visitor documentation
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1488544368-30622-29-git-send-email-armbru@redhat.com>
2017-03-05 09:14:20 +01:00
Markus Armbruster
a4a1c70dc7 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>
2017-03-05 09:14:20 +01:00
Markus Armbruster
048abb7b20 qapi: Drop unused non-strict qobject input visitor
The split between tests/test-qobject-input-visitor.c and
tests/test-qobject-input-strict.c now makes less sense than ever.  The
next commit will take care of that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1488544368-30622-20-git-send-email-armbru@redhat.com>
2017-03-05 09:14:19 +01:00
Markus Armbruster
a8aec6de2a 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>
2017-03-05 09:14:19 +01:00
Markus Armbruster
a9fc37f6bc qapi: Improve qobject input visitor error reporting
Error messages refer to nodes of the QObject being visited by name.
Trouble is the names are sometimes less than helpful:

* The name of the root QObject is whatever @name argument got passed
  to the visitor, except NULL gets mapped to "null".  We commonly pass
  NULL.  Not good.

  Avoiding errors "at the root" mitigates.  For instance,
  visit_start_struct() can only fail when the visited object is not a
  dictionary, and we commonly ensure it is beforehand.

* The name of a QDict's member is the member key.  Good enough only
  when this happens to be unique.

* The name of a QList's member is "null".  Not good.

Improve error messages by referring to nodes by path instead, as
follows:

* The path of the root QObject is whatever @name argument got passed
  to the visitor, except NULL gets mapped to "<anonymous>".

* The path of a root QDict's member is the member key.

* The path of a root QList's member is "[%u]", where %u is the list
  index, starting at zero.

* The path of a non-root QDict's member is the path of the QDict
  concatenated with "." and the member key.

* The path of a non-root QList's member is the path of the QList
  concatenated with "[%u]", where %u is the list index.

For example, the incorrect QMP command

    { "execute": "blockdev-add", "arguments": { "node-name": "foo", "driver": "raw", "file": {"driver": "file" } } }

now fails with

    {"error": {"class": "GenericError", "desc": "Parameter 'file.filename' is missing"}}

instead of

    {"error": {"class": "GenericError", "desc": "Parameter 'filename' is missing"}}

and

    { "execute": "input-send-event", "arguments": { "device": "bar", "events": [ [] ] } }

now fails with

    {"error": {"class": "GenericError", "desc": "Invalid parameter type for 'events[0]', expected: object"}}

instead of

    {"error": {"class": "GenericError", "desc": "Invalid parameter type for 'null', expected: QDict"}}

Aside: calling the thing "parameter" is suboptimal for QMP, because
the root object is "arguments" there.

The qobject output visitor doesn't have this problem because it should
not fail.  Same for dealloc and clone visitors.

The string visitors don't have this problem because they visit just
one value, whose name needs to be passed to the visitor as @name.  The
string output visitor shouldn't fail anyway.

The options visitor uses QemuOpts names.  Their name space is flat, so
the use of QDict member keys as names is fine.  NULL names used with
roots and lists could conceivably result in bad error messages.  Left
for another day.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1488544368-30622-15-git-send-email-armbru@redhat.com>
2017-03-05 09:14:19 +01:00
Markus Armbruster
99fb0c53c0 qmp: Eliminate silly QERR_QMP_* macros
The QERR_ macros are leftovers from the days of "rich" error objects.

QERR_QMP_BAD_INPUT_OBJECT, QERR_QMP_BAD_INPUT_OBJECT_MEMBER,
QERR_QMP_EXTRA_MEMBER are used in just one place now, except for one
use that has crept into qobject-input-visitor.c.

Drop these macros, to make the (bad) error messages more visible.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1488544368-30622-10-git-send-email-armbru@redhat.com>
2017-03-05 09:14:19 +01:00
Markus Armbruster
1527badb95 qapi: Support multiple command registries per program
The command registry encapsulates a single command list.  Give the
functions using it a parameter instead.  Define suitable command lists
in monitor, guest agent and test-qmp-commands.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1488544368-30622-6-git-send-email-armbru@redhat.com>
[Debugging turds buried]
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-05 09:12:25 +01:00
Stefan Weil
5bb8590d37 include: Fix typos found by codespell
Add also a missing parenthesis in a comment.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Acked-by: Alistair Francis <alistair.francis@xilinx.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2017-01-24 23:26:52 +03:00
Sascha Silbe
98cb89af4d error: error_setg_errno(): errno gets preserved
C11 allows errno to be clobbered by pretty much any library function
call, so in general callers need to take care to save errno before
calling other functions.

However, for error reporting functions this is rather awkward and can
make the code on the caller side more complicated than
necessary. error_setg_errno() already takes care of preserving errno
and some functions rely on that, so just promise that we continue to
do so in the future.

Signed-off-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Message-Id: <1469611466-31574-1-git-send-email-silbe@linux.vnet.ibm.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-01-19 15:42:36 +01:00
Daniel P. Berrange
603476c25c qdict: implement a qdict_crumple method for un-flattening a dict
The qdict_flatten() method will take a dict whose elements are
further nested dicts/lists and flatten them by concatenating
keys.

The qdict_crumple() method aims to do the reverse, taking a flat
qdict, and turning it into a set of nested dicts/lists. It will
apply nesting based on the key name, with a '.' indicating a
new level in the hierarchy. If the keys in the nested structure
are all numeric, it will create a list, otherwise it will create
a dict.

If the keys are a mixture of numeric and non-numeric, or the
numeric keys are not in strictly ascending order, an error will
be reported.

As an example, a flat dict containing

 {
   'foo.0.bar': 'one',
   'foo.0.wizz': '1',
   'foo.1.bar': 'two',
   'foo.1.wizz': '2'
 }

will get turned into a dict with one element 'foo' whose
value is a list. The list elements will each in turn be
dicts.

 {
   'foo': [
     { 'bar': 'one', 'wizz': '1' },
     { 'bar': 'two', 'wizz': '2' }
   ],
 }

If the key is intended to contain a literal '.', then it must
be escaped as '..'. ie a flat dict

  {
     'foo..bar': 'wizz',
     'bar.foo..bar': 'eek',
     'bar.hello': 'world'
  }

Will end up as

  {
     'foo.bar': 'wizz',
     'bar': {
        'foo.bar': 'eek',
        'hello': 'world'
     }
  }

The intent of this function is that it allows a set of QemuOpts
to be turned into a nested data structure that mirrors the nesting
used when the same object is defined over QMP.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1475246744-29302-3-git-send-email-berrange@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Parameter recursive dropped along with its tests; whitespace style
touched up]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-10-25 17:56:14 +02:00
Daniel P. Berrange
7d5e199ade qapi: rename QmpOutputVisitor to QObjectOutputVisitor
The QmpOutputVisitor has no direct dependency on QMP. It is
valid to use it anywhere that one wants a QObject. Rename it
to better reflect its functionality as a generic QAPI
to QObject converter.

The commit before previous renamed the files, this one renames C
identifiers.

Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1475246744-29302-6-git-send-email-berrange@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Split into file rename and identifier rename]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-10-25 16:25:54 +02:00
Daniel P. Berrange
09e68369a8 qapi: rename QmpInputVisitor to QObjectInputVisitor
The QmpInputVisitor has no direct dependency on QMP. It is
valid to use it anywhere that one has a QObject. Rename it
to better reflect its functionality as a generic QObject
to QAPI converter.

The previous commit renamed the files, this one renames C identifiers.

Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1475246744-29302-5-git-send-email-berrange@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Straightforwardly rebased, split into file and identifier rename]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-10-25 16:25:54 +02:00
Daniel P. Berrange
b3db211f3c qapi: rename *qmp-*-visitor* to *qobject-*-visitor*
The QMP visitors have no direct dependency on QMP. It is
valid to use them anywhere that one has a QObject. Rename them
to better reflect their functionality as a generic QObject
to QAPI converter.

This is the first of three parts: rename the files.  The next two
parts will rename C identifiers.  The split is necessary to make git
rename detection work.

Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Split into file and identifier rename, two comments touched up]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-10-25 16:25:48 +02:00
Markus Armbruster
60b03e4e6a qapi: Support unregistering QMP commands
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20160912091913.15831-7-marcandre.lureau@redhat.com>
2016-09-19 17:32:21 +02:00
Alberto Garcia
9df229c3ca blockjob: Update description of the 'id' field
The 'id' field of the BlockJob structure will be able to hold any ID,
not only a device name. This patch updates the description of that
field and the error messages where it is being used.

Soon we'll add the ability to set an arbitrary ID when creating a
block job.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-13 13:26:02 +02:00
Markus Armbruster
121d07125b Clean up header guards that don't match their file name
Header guard symbols should match their file name to make guard
collisions less likely.  Offenders found with
scripts/clean-header-guards.pl -vn.

Cleaned up with scripts/clean-header-guards.pl, followed by some
renaming of new guard symbols picked by the script to better ones.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:19:16 +02:00
Eric Blake
37f9e0a2b6 sockets: Use new QAPI cloning
Rather than rolling our own clone via an expensive conversion
in and back out of QObject, use the new clone visitor.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-15-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-07-06 10:52:04 +02:00
Eric Blake
a15fcc3cf6 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>
2016-07-06 10:52:04 +02:00
Eric Blake
3b098d5697 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>
2016-07-06 10:52:04 +02:00
Eric Blake
1830f22a67 qmp-output-visitor: Favor new visit_free() function
Now that we have a polymorphic visit_free(), we no longer need
qmp_output_visitor_cleanup(); however, we still need to
expose the subtype for qmp_output_get_qobject().

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-10-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-07-06 10:52:04 +02:00
Eric Blake
e7ca565629 string-output-visitor: Favor new visit_free() function
Now that we have a polymorphic visit_free(), we no longer need
string_output_visitor_cleanup(); however, we still need to
expose the subtype for string_output_get_string().

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-9-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-07-06 10:52:04 +02:00
Eric Blake
b70ce1018a qmp-input-visitor: Favor new visit_free() function
Now that we have a polymorphic visit_free(), we no longer need
qmp_input_visitor_cleanup(); which in turn means we no longer
need to return a subtype from qmp_input_visitor_new() nor a
public upcast function.

Generated code changes to qmp-marshal.c look like:

|@@ -52,11 +52,10 @@ void qmp_marshal_add_fd(QDict *args, QOb
| {
|     Error *err = NULL;
|     AddfdInfo *retval;
|-    QmpInputVisitor *qiv = qmp_input_visitor_new(QOBJECT(args), true);
|     Visitor *v;
|     q_obj_add_fd_arg arg = {0};
|
|-    v = qmp_input_get_visitor(qiv);
|+    v = qmp_input_visitor_new(QOBJECT(args), true);
|     visit_start_struct(v, NULL, NULL, 0, &err);
|     if (err) {
|         goto out;

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-8-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-07-06 10:52:04 +02:00
Eric Blake
7a0525c7be string-input-visitor: Favor new visit_free() function
Now that we have a polymorphic visit_free(), we no longer need
string_input_visitor_cleanup(); which in turn means we no longer
need to return a subtype from string_input_visitor_new() nor a
public upcast function.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-7-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-07-06 10:52:04 +02:00
Eric Blake
09204eac9b opts-visitor: Favor new visit_free() function
Now that we have a polymorphic visit_free(), we no longer need
opts_visitor_cleanup(); which in turn means we no longer need
to return a subtype from opts_visitor_new() nor a public upcast
function.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-6-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-07-06 10:52:04 +02:00
Eric Blake
2c0ef9f411 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>
2016-07-06 10:52:04 +02:00
Eric Blake
1158bb2a05 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>
2016-07-06 10:52:04 +02:00
Eric Blake
c7eb39cbd4 qapi: Improve use of qmp/types.h
'qjson.h' is not a QObject subtype; include this file directly in
.c files that are using it, rather than abusing qmp/types.h for
that purpose.

Meanwhile, for files that include a list of individual QObject
subtypes, it's easier to just use qmp/types.h for that purpose.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-2-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-07-06 10:52:03 +02:00
Daniel P. Berrange
d59ce6f344 migration: add reporting of errors for outgoing migration
Currently if an application initiates an outgoing migration,
it may or may not, get an error reported back on failure. If
the error occurs synchronously to the 'migrate' command
execution, the client app will see the error message. This
is the case for DNS lookup failures. If the error occurs
asynchronously to the monitor command though, the error
will be thrown away and the client left guessing about
what went wrong. This is the case for failure to connect
to the TCP server (eg due to wrong port, or firewall
rules, or other similar errors).

In the future we'll be adding more scope for errors to
happen asynchronously with the TLS protocol handshake.
TLS errors are hard to diagnose even when they are well
reported, so discarding errors entirely will make it
impossible to debug TLS connection problems.

Management apps which do migration are already using
'query-migrate' / 'info migrate' to check up on progress
of background migration operations and to see their end
status. This is a fine place to also include the error
message when things go wrong.

This patch thus adds an 'error-desc' field to the
MigrationInfo struct, which will be populated when
the 'status' is set to 'failed':

(qemu) migrate -d tcp:localhost:9001
(qemu) info migrate
capabilities: xbzrle: off rdma-pin-all: off auto-converge: off zero-blocks: off compress: off events: off x-postcopy-ram: off
Migration status: failed (Error connecting to socket: Connection refused)
total time: 0 milliseconds

In the HMP, when doing non-detached migration, it is
also possible to display this error message directly
to the app.

(qemu) migrate tcp:localhost:9001
Error connecting to socket: Connection refused

Or with QMP

  {
    "execute": "query-migrate",
    "arguments": {}
  }
  {
    "return": {
      "status": "failed",
      "error-desc": "address resolution failed for myhost:9000: No address associated with hostname"
    }
  }

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <1461751518-12128-11-git-send-email-berrange@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2016-05-26 11:31:30 +05:30
Eric Blake
68ab47e4b4 qapi: Change visit_type_FOO() to no longer return partial objects
Returning a partial object on error is an invitation for a careless
caller to leak memory.  We already fixed things in an earlier
patch to guarantee NULL if visit_start fails ("qapi: Guarantee
NULL obj on input visitor callback error"), but that does not
help the case where visit_start succeeds but some other failure
happens before visit_end, such that we leak a partially constructed
object outside visit_type_FOO(). As no one outside the testsuite
was actually relying on these semantics, it is cleaner to just
document and guarantee that ALL pointer-based visit_type_FOO()
functions always leave a safe value in *obj during an input visitor
(either the new object on success, or NULL if an error is
encountered), so callers can now unconditionally use
qapi_free_FOO() to clean up regardless of whether an error occurred.

The decision is done by adding visit_is_input(), then updating the
generated code to check if additional cleanup is needed based on
the type of visitor in use.

Note that we still leave *obj unchanged after a scalar-based
visit_type_FOO(); I did not feel like auditing all uses of
visit_type_Enum() to see if the callers would tolerate a specific
sentinel value (not to mention having to decide whether it would
be better to use 0 or ENUM__MAX as that sentinel).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-25-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:55 +02:00
Eric Blake
d9f62dde13 qapi: Simplify semantics of visit_next_list()
The semantics of the list visit are somewhat baroque, with the
following pseudocode when FooList is used:

start()
for (prev = head; cur = next(prev); prev = &cur) {
    visit(&cur->value)
}

Note that these semantics (advance before visit) requires that
the first call to next() return the list head, while all other
calls return the next element of the list; that is, every visitor
implementation is required to track extra state to decide whether
to return the input as-is, or to advance.  It also requires an
argument of 'GenericList **' to next(), solely because the first
iteration might need to modify the caller's GenericList head, so
that all other calls have to do a layer of dereferencing.

Thankfully, we only have two uses of list visits in the entire
code base: one in spapr_drc (which completely avoids
visit_next_list(), feeding in integers from a different source
than uint8List), and one in qapi-visit.py.  That is, all other
list visitors are generated in qapi-visit.c, and share the same
paradigm based on a qapi FooList type, so we can refactor how
lists are laid out with minimal churn among clients.

We can greatly simplify things by hoisting the special case
into the start() routine, and flipping the order in the loop
to visit before advance:

start(head)
for (tail = *head; tail; tail = next(tail)) {
    visit(&tail->value)
}

With the simpler semantics, visitors have less state to track,
the argument to next() is reduced to 'GenericList *', and it
also becomes obvious whether an input visitor is allocating a
FooList during visit_start_list() (rather than the old way of
not knowing if an allocation happened until the first
visit_next_list()).  As a minor drawback, we now allocate in
two functions instead of one, and have to pass the size to
both functions (unless we were to tweak the input visitors to
cache the size to start_list for reuse during next_list, but
that defeats the goal of less visitor state).

The signature of visit_start_list() is chosen to match
visit_start_struct(), with the new parameters after 'name'.

The spapr_drc case is a virtual visit, done by passing NULL for
list, similarly to how NULL is passed to visit_start_struct()
when a qapi type is not used in those visits.  It was easy to
provide these semantics for qmp-output and dealloc visitors,
and a bit harder for qmp-input (several prerequisite patches
refactored things to make this patch straightforward).  But it
turned out that the string and opts visitors munge enough other
state during visit_next_list() to make it easier to just
document and require a GenericList visit for now; an assertion
will remind us to adjust things if we need the semantics in the
future.

Several pre-requisite cleanup patches made the reshuffling of
the various visitors easier; particularly the qmp input visitor.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-24-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:55 +02:00
Eric Blake
15c2f669e3 qapi: Split visit_end_struct() into pieces
As mentioned in previous patches, we want to call visit_end_struct()
functions unconditionally, so that visitors can release resources
tied up since the matching visit_start_struct() without also having
to worry about error priority if more than one error occurs.

Even though error_propagate() can be safely used to ignore a second
error during cleanup caused by a first error, it is simpler if the
cleanup cannot set an error.  So, split out the error checking
portion (basically, input visitors checking for unvisited keys) into
a new function visit_check_struct(), which can be safely skipped if
any earlier errors are encountered, and leave the cleanup portion
(which never fails, but must be called unconditionally if
visit_start_struct() succeeded) in visit_end_struct().

Generated code in qapi-visit.c has diffs resembling:

|@@ -59,10 +59,12 @@ void visit_type_ACPIOSTInfo(Visitor *v,
|         goto out_obj;
|     }
|     visit_type_ACPIOSTInfo_members(v, obj, &err);
|-    error_propagate(errp, err);
|-    err = NULL;
|+    if (err) {
|+        goto out_obj;
|+    }
|+    visit_check_struct(v, &err);
| out_obj:
|-    visit_end_struct(v, &err);
|+    visit_end_struct(v);
| out:

and in qapi-event.c:

@@ -47,7 +47,10 @@ void qapi_event_send_acpi_device_ost(ACP
|         goto out;
|     }
|     visit_type_q_obj_ACPI_DEVICE_OST_arg_members(v, &param, &err);
|-    visit_end_struct(v, err ? NULL : &err);
|+    if (!err) {
|+        visit_check_struct(v, &err);
|+    }
|+    visit_end_struct(v);
|     if (err) {
|         goto out;

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-20-git-send-email-eblake@redhat.com>
[Conflict with a doc fixup resolved]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:55 +02:00
Eric Blake
3bc97fd592 qapi: Add visit_type_null() visitor
Right now, qmp-output-visitor happens to produce a QNull result
if nothing is actually visited between the creation of the visitor
and the request for the resulting QObject.  A stronger protocol
would require that a QMP output visit MUST visit something.  But
to still be able to produce a JSON 'null' output, we need a new
visitor function that states our intentions.  Yes, we could say
that such a visit must go through visit_type_any(), but that
feels clunky.

So this patch introduces the new visit_type_null() interface and
its no-op interface in the dealloc visitor, and stubs in the
qmp visitors (the next patch will finish the implementation).
For the visitors that will not implement the callback, document
the situation. The code in qapi-visit-core unconditionally
dereferences the callback pointer, so that a segfault will inform
a developer if they need to implement the callback for their
choice of visitor.

Note that JSON has a primitive null type, with the single value
null; likewise with the QNull type for QObject; but for QAPI,
we just have the 'null' value without a null type.  We may
eventually want to add more support in QAPI for null (most likely,
we'd use it via an alternate type that permits 'null' or an
object); but we'll create that usage when we need it.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-15-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:54 +02:00
Eric Blake
adfb264c9e qapi: Document visitor interfaces, add assertions
The visitor interface for mapping between QObject/QemuOpts/string
and QAPI is scandalously under-documented, making changes to visitor
core, individual visitors, and users of visitors difficult to
coordinate.  Among other questions: when is it safe to pass NULL,
vs. when a string must be provided; which visitors implement which
callbacks; the difference between concrete and virtual visits.

Correct this by retrofitting proper contracts, and document where some
of the interface warts remain (for example, we may want to modify
visit_end_* to require the same 'obj' as the visit_start counterpart,
so the dealloc visitor can be simplified).  Later patches in this
series will tackle some, but not all, of these warts.

Add assertions to (partially) enforce the contract.  Some of these
were only made possible by recent cleanup commits.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-13-git-send-email-eblake@redhat.com>
[Doc fix from Eric squashed in]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:54 +02:00
Eric Blake
fc471c18d5 qapi: Consolidate QMP input visitor creation
Rather than having two separate ways to create a QMP input
visitor, where the safer approach has the more verbose name,
it is better to consolidate things into a single function
where the caller must explicitly choose whether to be strict
or to ignore excess input.  This patch is the strictly
mechanical conversion; the next patch will then audit which
uses can be made stricter.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-6-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:54 +02:00
Eric Blake
42a502a7a6 qmp: Drop dead command->type
Ever since QMP was first added back in commit 43c20a43, we have
never had any QmpCommandType other than QCT_NORMAL.  It's
pointless to carry around the cruft.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-4-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:54 +02:00
Eric Blake
983f52d4b3 qapi-visit: Add visitor.type classification
We have three classes of QAPI visitors: input, output, and dealloc.
Currently, all implementations of these visitors have one thing in
common based on their visitor type: the implementation used for the
visit_type_enum() callback.  But since we plan to add more such
common behavior, in relation to documenting and further refining
the semantics, it makes more sense to have the visitor
implementations advertise which class they belong to, so the common
qapi-visit-core code can use that information in multiple places.

A later patch will better document the types of visitors directly
in visitor.h.

For this patch, knowing the class of a visitor implementation lets
us make input_type_enum() and output_type_enum() become static
functions, by replacing the callback function Visitor.type_enum()
with the simpler enum member Visitor.type.  Share a common
assertion in qapi-visit-core as part of the refactoring.

Move comments in opts-visitor.c to match the refactored layout.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-2-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:54 +02:00
Markus Armbruster
14b6d44d47 Use scripts/clean-includes to drop redundant qemu/typedefs.h
Re-run scripts/clean-includes to apply the previous commit's
corrections and updates.  Besides redundant qemu/typedefs.h, this only
finds a redundant config-host.h include in ui/egl-helpers.c.  No idea
how that escaped the previous runs.

Some manual whitespace trimming around dropped includes squashed in.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:16 +01:00
Markus Armbruster
da34e65cb4 include/qemu/osdep.h: Don't include qapi/error.h
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the
Error typedef.  Since then, we've moved to include qemu/osdep.h
everywhere.  Its file comment explains: "To avoid getting into
possible circular include dependencies, this file should not include
any other QEMU headers, with the exceptions of config-host.h,
compiler.h, os-posix.h and os-win32.h, all of which are doing a
similar job to this file and are under similar constraints."
qapi/error.h doesn't do a similar job, and it doesn't adhere to
similar constraints: it includes qapi-types.h.  That's in excess of
100KiB of crap most .c files don't actually need.

Add the typedef to qemu/typedefs.h, and include that instead of
qapi/error.h.  Include qapi/error.h in .c files that need it and don't
get it now.  Include qapi-types.h in qom/object.h for uint16List.

Update scripts/clean-includes accordingly.  Update it further to match
reality: replace config.h by config-target.h, add sysemu/os-posix.h,
sysemu/os-win32.h.  Update the list of includes in the qemu/osdep.h
comment quoted above similarly.

This reduces the number of objects depending on qapi/error.h from "all
of them" to less than a third.  Unfortunately, the number depending on
qapi-types.h shrinks only a little.  More work is needed for that one.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
[Fix compilation without the spice devel packages. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:15 +01:00
Max Reitz
a55448b368 qapi: Drop QERR_UNKNOWN_BLOCK_FORMAT_FEATURE
Just specifying a custom string is simpler in basically all places that
used it, and in addition, specifying the BB or node name is something we
generally do not do in other error messages when opening a BDS, so we
should not do it here.

This changes the output for iotest 036 (to the better, in my opinion),
so the reference output needs to be changed accordingly.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-17 15:47:56 +01:00
Peter Maydell
90ce6e2644 include: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

NB: If this commit breaks compilation for your out-of-tree
patchseries or fork, then you need to make sure you add
#include "qemu/osdep.h" to any new .c files that you have.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-02-23 12:43:05 +00:00
Eric Blake
dbf1192262 qapi: Change visit_start_implicit_struct to visit_start_alternate
After recent changes, the only remaining use of
visit_start_implicit_struct() is for allocating the space needed
when visiting an alternate.  Since the term 'implicit struct' is
hard to explain, rename the function to its current usage.  While
at it, we can merge the functionality of visit_get_next_type()
into the same function, making it more like visit_start_struct().

Generated code is now slightly smaller:

| {
|     Error *err = NULL;
|
|-    visit_start_implicit_struct(v, (void**) obj, sizeof(BlockdevRef), &err);
|+    visit_start_alternate(v, name, (GenericAlternate **)obj, sizeof(**obj),
|+                          true, &err);
|     if (err) {
|         goto out;
|     }
|-    visit_get_next_type(v, name, &(*obj)->type, true, &err);
|-    if (err) {
|-        goto out_obj;
|-    }
|     switch ((*obj)->type) {
|     case QTYPE_QDICT:
|         visit_start_struct(v, name, NULL, 0, &err);
...
|     }
|-out_obj:
|-    visit_end_implicit_struct(v);
|+    visit_end_alternate(v);
| out:
|     error_propagate(errp, err);
| }

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1455778109-6278-16-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-19 11:08:57 +01:00
Eric Blake
544a373159 qapi: Don't box branches of flat unions
There's no reason to do two malloc's for a flat union; let's just
inline the branch struct directly into the C union branch of the
flat union.

Surprisingly, fewer clients were actually using explicit references
to the branch types in comparison to the number of flat unions
thus modified.

This lets us reduce the hack in qapi-types:gen_variants() added in
the previous patch; we no longer need to distinguish between
alternates and flat unions.

The change to unboxed structs means that u.data (added in commit
cee2dedb) is now coincident with random fields of each branch of
the flat union, whereas beforehand it was only coincident with
pointers (since all branches of a flat union have to be objects).
Note that this was already the case for simple unions - but there
we got lucky.  Remember, visit_start_union() blindly returns true
for all visitors except for the dealloc visitor, where it returns
the value !!obj->u.data, and that this result then controls
whether to proceed with the visit to the variant.  Pre-patch,
this meant that flat unions were testing whether the boxed pointer
was still NULL, and thereby skipping visit_end_implicit_struct()
and avoiding a NULL dereference if the pointer had not been
allocated.  The same was true for simple unions where the current
branch had pointer type, except there we bypassed visit_type_FOO().
But for simple unions where the current branch had scalar type, the
contents of that scalar meant that the decision to call
visit_type_FOO() was data-dependent - the reason we got lucky there
is that visit_type_FOO() for all scalar types in the dealloc visitor
is a no-op (only the pointer variants had anything to free), so it
did not matter whether the dealloc visit was skipped.  But with this
patch, we would risk leaking memory if we could skip a call to
visit_type_FOO_fields() based solely on a data-dependent decision.

But notice: in the dealloc visitor, visit_type_FOO() already handles
a NULL obj - it was only the visit_type_implicit_FOO() that was
failing to check for NULL. And now that we have refactored things to
have the branch be part of the parent struct, we no longer have a
separate pointer that can be NULL in the first place.  So we can just
delete the call to visit_start_union() altogether, and blindly visit
the branch type; there is no change in behavior except to the dealloc
visitor, where we now unconditionally visit the branch, but where that
visit is now always safe (for a flat union, we can no longer
dereference NULL, and for a simple union, visit_type_FOO() was already
safely handling NULL on pointer types).

Unfortunately, simple unions are not as easy to switch to unboxed
layout; because we are special-casing the hidden implicit type with
a single 'data' member, we really DO need to keep calling another
layer of visit_start_struct(), with a second malloc; although there
are some cleanups planned for simple unions in later patches.

visit_start_union() and gen_visit_implicit_struct() are now unused.
Drop them.

Note that after this patch, the only remaining use of
visit_start_implicit_struct() is for alternate types; the next patch
will do further cleanup based on that fact.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1455778109-6278-14-git-send-email-eblake@redhat.com>
[Dead code deletion squashed in, commit message updated accordingly]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-19 11:08:57 +01:00
Eric Blake
e65d89bf1a qapi: Adjust layout of FooList types
By sticking the next pointer first, we don't need a union with
64-bit padding for smaller types.  On 32-bit platforms, this
can reduce the size of uint8List from 16 bytes (or 12, depending
on whether 64-bit ints can tolerate 4-byte alignment) down to 8.
It has no effect on 64-bit platforms (where alignment still
dictates a 16-byte struct); but fewer anonymous unions is still
a win in my book.

It requires visit_next_list() to gain a size parameter, to know
what size element to allocate; comparable to the size parameter
of visit_start_struct().

I debated about going one step further, to allow for fewer casts,
by doing:
    typedef GenericList GenericList;
    struct GenericList {
        GenericList *next;
    };
    struct FooList {
        GenericList base;
        Foo *value;
    };
so that you convert to 'GenericList *' by '&foolist->base', and
back by 'container_of(generic, GenericList, base)' (as opposed to
the existing '(GenericList *)foolist' and '(FooList *)generic').
But doing that would require hoisting the declaration of
GenericList prior to inclusion of qapi-types.h, rather than its
current spot in visitor.h; it also makes iteration a bit more
verbose through 'foolist->base.next' instead of 'foolist->next'.

Note that for lists of objects, the 'value' payload is still
hidden behind a boxed pointer.  Someday, it would be nice to do:

struct FooList {
    FooList *next;
    Foo value;
};

for one less level of malloc for each list element.  This patch
is a step in that direction (now that 'next' is no longer at a
fixed non-zero offset within the struct, we can store more than
just a pointer's-worth of data as the value payload), but the
actual conversion would be a task for another series, as it will
touch a lot of code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1455778109-6278-10-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-19 11:08:57 +01:00
Peter Maydell
84c0781103 Error reporting patches for 2016-02-09
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Merge remote-tracking branch 'remotes/armbru/tags/pull-error-2016-02-09' into staging

Error reporting patches for 2016-02-09

# gpg: Signature made Tue 09 Feb 2016 12:38:33 GMT using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/pull-error-2016-02-09:
  HACKING: Add a section on error handling and reporting
  error: Improve documentation some more
  Use error_fatal to simplify obvious fatal errors (again)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-02-09 16:09:15 +00:00
Markus Armbruster
10303f04b9 error: Improve documentation some more
Don't claim error_report_err() always reports to stderr.  It actually
reports to the current monitor when we have one.

Clarify intended use of error_abort and error_fatal.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1454522628-28294-2-git-send-email-armbru@redhat.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
2016-02-09 13:19:41 +01:00
Eric Blake
08f9541dec qapi: Drop unused error argument for list and implicit struct
No backend was setting an error when ending the visit of a list or
implicit struct, or when moving to the next list node.  Make the
callers a bit easier to follow by making this a part of the contract,
and removing the errp argument - callers can then unconditionally end
an object as part of cleanup without having to think about whether a
second error is dominated by a first, because there is no second
error.

A later patch will then tackle the larger task of splitting
visit_end_struct(), which can indeed set an error.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1454075341-13658-24-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08 17:29:57 +01:00
Eric Blake
337283dffb qapi: Drop unused 'kind' for struct/enum visit
visit_start_struct() and visit_type_enum() had a 'kind' argument
that was usually set to either the stringized version of the
corresponding qapi type name, or to NULL (although some clients
didn't even get that right).  But nothing ever used the argument.
It's even hard to argue that it would be useful in a debugger,
as a stack backtrace also tells which type is being visited.

Therefore, drop the 'kind' argument as dead.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1454075341-13658-22-git-send-email-eblake@redhat.com>
[Harmless rebase mistake cleaned up]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08 17:29:57 +01:00
Eric Blake
0b2a0d6bb2 qapi: Swap 'name' in visit_* callbacks to match public API
As explained in the previous patches, matching argument order of
'name, &value' to JSON's "name":value makes sense.  However,
while the last two patches were easy with Coccinelle, I ended up
doing this one all by hand.  Now all the visitor callbacks match
the main interface.

The compiler is able to enforce that all clients match the changed
interface in visitor-impl.h, even where two pointers are being
swapped, because only one of the two pointers is const (if that
were not the case, then C's looseness on treating 'char *' like
'void *' would have made review a bit harder).

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1454075341-13658-21-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08 17:29:56 +01:00
Eric Blake
51e72bc1dd qapi: Swap visit_* arguments for consistent 'name' placement
JSON uses "name":value, but many of our visitor interfaces were
called with visit_type_FOO(v, &value, name, errp).  This can be
a bit confusing to have to mentally swap the parameter order to
match JSON order.  It's particularly bad for visit_start_struct(),
where the 'name' parameter is smack in the middle of the
otherwise-related group of 'obj, kind, size' parameters! It's
time to do a global swap of the parameter ordering, so that the
'name' parameter is always immediately after the Visitor argument.

Additional reason in favor of the swap: the existing include/qjson.h
prefers listing 'name' first in json_prop_*(), and I have plans to
unify that file with the qapi visitors; listing 'name' first in
qapi will minimize churn to the (admittedly few) qjson.h clients.

Later patches will then fix docs, object.h, visitor-impl.h, and
those clients to match.

Done by first patching scripts/qapi*.py by hand to make generated
files do what I want, then by running the following Coccinelle
script to affect the rest of the code base:
 $ spatch --sp-file script `git grep -l '\bvisit_' -- '**/*.[ch]'`
I then had to apply some touchups (Coccinelle insisted on TAB
indentation in visitor.h, and botched the signature of
visit_type_enum() by rewriting 'const char *const strings[]' to
the syntactically invalid 'const char*const[] strings').  The
movement of parameters is sufficient to provoke compiler errors
if any callers were missed.

    // Part 1: Swap declaration order
    @@
    type TV, TErr, TObj, T1, T2;
    identifier OBJ, ARG1, ARG2;
    @@
     void visit_start_struct
    -(TV v, TObj OBJ, T1 ARG1, const char *name, T2 ARG2, TErr errp)
    +(TV v, const char *name, TObj OBJ, T1 ARG1, T2 ARG2, TErr errp)
     { ... }

    @@
    type bool, TV, T1;
    identifier ARG1;
    @@
     bool visit_optional
    -(TV v, T1 ARG1, const char *name)
    +(TV v, const char *name, T1 ARG1)
     { ... }

    @@
    type TV, TErr, TObj, T1;
    identifier OBJ, ARG1;
    @@
     void visit_get_next_type
    -(TV v, TObj OBJ, T1 ARG1, const char *name, TErr errp)
    +(TV v, const char *name, TObj OBJ, T1 ARG1, TErr errp)
     { ... }

    @@
    type TV, TErr, TObj, T1, T2;
    identifier OBJ, ARG1, ARG2;
    @@
     void visit_type_enum
    -(TV v, TObj OBJ, T1 ARG1, T2 ARG2, const char *name, TErr errp)
    +(TV v, const char *name, TObj OBJ, T1 ARG1, T2 ARG2, TErr errp)
     { ... }

    @@
    type TV, TErr, TObj;
    identifier OBJ;
    identifier VISIT_TYPE =~ "^visit_type_";
    @@
     void VISIT_TYPE
    -(TV v, TObj OBJ, const char *name, TErr errp)
    +(TV v, const char *name, TObj OBJ, TErr errp)
     { ... }

    // Part 2: swap caller order
    @@
    expression V, NAME, OBJ, ARG1, ARG2, ERR;
    identifier VISIT_TYPE =~ "^visit_type_";
    @@
    (
    -visit_start_struct(V, OBJ, ARG1, NAME, ARG2, ERR)
    +visit_start_struct(V, NAME, OBJ, ARG1, ARG2, ERR)
    |
    -visit_optional(V, ARG1, NAME)
    +visit_optional(V, NAME, ARG1)
    |
    -visit_get_next_type(V, OBJ, ARG1, NAME, ERR)
    +visit_get_next_type(V, NAME, OBJ, ARG1, ERR)
    |
    -visit_type_enum(V, OBJ, ARG1, ARG2, NAME, ERR)
    +visit_type_enum(V, NAME, OBJ, ARG1, ARG2, ERR)
    |
    -VISIT_TYPE(V, OBJ, NAME, ERR)
    +VISIT_TYPE(V, NAME, OBJ, ERR)
    )

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1454075341-13658-19-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08 17:29:56 +01:00
Eric Blake
04e070d217 qapi: Consolidate visitor small integer callbacks
Commit 4e27e819 introduced optional visitor callbacks for all
sorts of int types, but no visitor has supplied any of the
callbacks for sizes less than 64 bits.  In other words, the
generic implementation based on using type_[u]int64() followed
by bounds-checking works just fine. In the interest of
simplicity, it's easier to make the visitor callback interface
not have to worry about the other sizes.

Adding some helper functions minimizes the boilerplate required
to correct FIXMEs added earlier with regards to questionable
reuse of errp, particularly now that we can guarantee from a
single file audit that value is unchanged if an error is set.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1454075341-13658-16-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08 17:29:55 +01:00
Eric Blake
f755dea79d qapi: Make all visitors supply uint64 callbacks
Our qapi visitor contract supports multiple integer visitors,
but left the type_uint64 visitor as optional (falling back on
type_int64); which in turn can lead to awkward behavior with
numbers larger than INT64_MAX (the user has to be aware of
twos complement, and deal with negatives).

This patch does not address the disparity in handling large
values as negatives.  It merely moves the fallback from uint64
to int64 from the visitor core to the visitors, where the issue
can actually be fixed, by implementing the missing type_uint64()
callbacks on top of the respective type_int64() callbacks, and
with a FIXME comment explaining why that's wrong.

With that done, we now have a type_uint64() callback in every
driver, so we can make it mandatory from the core.  And although
the type_int64() callback can cover the entire valid range of
type_uint{8,16,32} on valid user input, using type_uint64() to
avoid mixed signedness makes more sense.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1454075341-13658-15-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08 17:29:55 +01:00
Eric Blake
4c40314a35 qapi: Prefer type_int64 over type_int in visitors
The qapi builtin type 'int' is basically shorthand for the type
'int64'.  In fact, since no visitor was providing the optional
type_int64() callback, visit_type_int64() was just always falling
back to type_int(), cementing the equivalence between the types.

However, some visitors are providing a type_uint64() callback.
For purposes of code consistency, it is nicer if all visitors
use the paired type_int64/type_uint64 names rather than the
mismatched type_int/type_uint64.  So this patch just renames
the signed int callbacks in place, dropping the type_int()
callback as redundant, and a later patch will focus on the
unsigned int callbacks.

Add some FIXMEs to questionable reuse of errp in code touched
by the rename, while at it (the reuse works as long as the
callbacks don't modify value when setting an error, but it's not
a good example to set) - a later patch will then fix those.

No change in functionality here, although further cleanups are
in the pipeline.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1454075341-13658-14-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08 17:29:55 +01:00
Eric Blake
7c91aabd89 qapi-visit: Kill unused visit_end_union()
The generated code can call visit_end_union() without having called
visit_start_union().  Example:

        if (!*obj) {
            goto out_obj;
        }
        visit_type_CpuInfoBase_fields(v, (CpuInfoBase **)obj, &err);
        if (err) {
            goto out_obj; // if we go from here...
        }
        if (!visit_start_union(v, !!(*obj)->u.data, &err) || err) {
            goto out_obj;
        }
        switch ((*obj)->arch) {
    [...]
        }
    out_obj:
        // ... then *obj is true, and ...
        error_propagate(errp, err);
        err = NULL;
        if (*obj) {
            // we end up here
            visit_end_union(v, !!(*obj)->u.data, &err);
        }
        error_propagate(errp, err);

Harmless only because no visitor implements end_union().  Clean it up
anyway, by deleting the function as useless.

Messed up since we have visit_end_union (commit cee2ded).

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1453902888-20457-3-git-send-email-armbru@redhat.com>
[expand scope of patch to delete rather than repair]
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1454075341-13658-13-git-send-email-eblake@redhat.com>
2016-02-08 17:29:55 +01:00
Markus Armbruster
8277d2aa58 error: New error_prepend(), error_reportf_err()
Instead of simply propagating an error verbatim, we sometimes want to
add to its message, like this:

    frobnicate(arg, &err);
    error_setg(errp, "Can't frobnicate %s: %s",
                     arg, error_get_pretty(err));
    error_free(err);

This is suboptimal, because it loses err's hint (if any).  Moreover,
when errp is &error_abort or is subsequently propagated to
&error_abort, the abort message points to the place where we last
added to the error, not to the place where it originated.

To avoid these issues, provide means to add to an error's message in
place:

    frobnicate(arg, errp);
    error_prepend(errp, "Can't frobnicate %s: ", arg);

Likewise, reporting an error like

    frobnicate(arg, &err);
    error_report("Can't frobnicate %s: %s", arg, error_get_pretty(err));

can lose err's hint.  To avoid:

    error_reportf_err(err, "Can't frobnicate %s: ", arg);

The next commits will put these functions to use.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1450452927-8346-10-git-send-email-armbru@redhat.com>
2016-01-13 15:16:17 +01:00
Markus Armbruster
f4d0064afc error: Improve documentation
While there, tighten error_append_hint()'s assertion.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1450452927-8346-6-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-01-13 15:16:16 +01:00
Markus Armbruster
8d780f4392 error: Document how to accumulate multiple errors
Suggested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447776349-2344-1-git-send-email-armbru@redhat.com>
2016-01-13 11:58:57 +01:00
Eric Blake
29637a6ee9 qapi: Shorter visits of optional fields
For less code, reflect the determined boolean value of an optional
visit back to the caller instead of making the caller read the
boolean after the fact.

The resulting generated code has the following diff:

|-    visit_optional(v, &has_fdset_id, "fdset-id");
|-    if (has_fdset_id) {
|+    if (visit_optional(v, &has_fdset_id, "fdset-id")) {
|         visit_type_int(v, &fdset_id, "fdset-id", &err);
|         if (err) {
|             goto out;
|         }
|     }

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1449033659-25497-10-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:29 +01:00
Eric Blake
5cdc8831a7 qapi: Simplify visits of optional fields
None of the visitor callbacks would set an error when testing
if an optional field was present; make this part of the interface
contract by eliminating the errp argument.

The resulting generated code has a nice diff:

|-    visit_optional(v, &has_fdset_id, "fdset-id", &err);
|-    if (err) {
|-        goto out;
|-    }
|+    visit_optional(v, &has_fdset_id, "fdset-id");
|     if (has_fdset_id) {
|         visit_type_int(v, &fdset_id, "fdset-id", &err);
|         if (err) {
|             goto out;
|         }
|     }

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1449033659-25497-9-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:29 +01:00
Eric Blake
d00341af38 qapi: Fix alternates that accept 'number' but not 'int'
The QMP input visitor allows integral values to be assigned by
promotion to a QTYPE_QFLOAT.  However, when parsing an alternate,
we did not take this into account, such that an alternate that
accepts 'number' and some other type, but not 'int', would reject
integral values.

With this patch, we now have the following desirable table:

    alternate has      case selected for
    'int'  'number'    QTYPE_QINT  QTYPE_QFLOAT
      no        no     error       error
      no       yes     'number'    'number'
     yes        no     'int'       error
     yes       yes     'int'       'number'

While it is unlikely that we will ever use 'number' in an
alternate other than in the testsuite, it never hurts to be
more precise in what we allow.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1449033659-25497-8-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:28 +01:00
Eric Blake
0426d53c65 qapi: Simplify visiting of alternate types
Previously, working with alternates required two lookup arrays
and some indirection: for type Foo, we created Foo_qtypes[]
which maps each qtype to a value of the generated FooKind enum,
then look up that value in FooKind_lookup[] like we do for other
union types.

This has a couple of subtle bugs.  First, the generator was
creating a call with a parameter '(int *) &(*obj)->type' where
type is an enum type; this is unsafe if the compiler chooses
to store the enum type in a different size than int, where
assigning through the wrong size pointer can corrupt data or
cause a SIGBUS.

Related bug, not not fixed in this patch: qapi-visit.py's
gen_visit_enum() generates a cast of its enum * argument to
int *. Marked FIXME.

Second, since the values of the FooKind enum start at zero, all
entries of the Foo_qtypes[] array that were not explicitly
initialized will map to the same branch of the union as the
first member of the alternate, rather than triggering a desired
failure in visit_get_next_type().  Fortunately, the bug seldom
bites; the very next thing the input visitor does is try to
parse the incoming JSON with the wrong parser, which normally
fails; the output visitor is not used with a C struct in that
state, and the dealloc visitor has nothing to clean up (so
there is no leak).

However, the second bug IS observable in one case: parsing an
integer causes unusual behavior in an alternate that contains
at least a 'number' member but no 'int' member, because the
'number' parser accepts QTYPE_QINT in addition to the expected
QTYPE_QFLOAT (that is, since 'int' is not a member, the type
QTYPE_QINT accidentally maps to FooKind 0; if this enum value
is the 'number' branch the integer parses successfully, but if
the 'number' branch is not first, some other branch tries to
parse the integer and rejects it).  A later patch will worry
about fixing alternates to always parse all inputs that a
non-alternate 'number' would accept, for now this is still
marked FIXME in the updated test-qmp-input-visitor.c, to
merely point out that new undesired behavior of 'ans' matches
the existing undesired behavior of 'asn'.

This patch fixes the default-initialization bug by deleting the
indirection, and modifying get_next_type() to directly assign a
QTypeCode parameter.  This in turn fixes the type-casting bug,
as we are no longer casting a pointer to enum to a questionable
size. There is no longer a need to generate an implicit FooKind
enum associated with the alternate type (since the QMP wire
format never uses the stringized counterparts of the C union
member names).  Since the updated visit_get_next_type() does not
know which qtypes are expected, the generated visitor is
modified to generate an error statement if an unexpected type is
encountered.

Callers now have to know the QTYPE_* mapping when looking at the
discriminator; but so far, only the testsuite was even using the
C struct of an alternate types.  I considered the possibility of
keeping the internal enum FooKind, but initialized differently
than most generated arrays, as in:
  typedef enum FooKind {
      FOO_KIND_A = QTYPE_QDICT,
      FOO_KIND_B = QTYPE_QINT,
  } FooKind;
to create nicer aliases for knowing when to use foo->a or foo->b
when inspecting foo->type; but it turned out to add too much
complexity, especially without a client.

There is a user-visible side effect to this change, but I
consider it to be an improvement. Previously,
the invalid QMP command:
  {"execute":"blockdev-add", "arguments":{"options":
    {"driver":"raw", "id":"a", "file":true}}}
failed with:
  {"error": {"class": "GenericError",
    "desc": "Invalid parameter type for 'file', expected: QDict"}}
(visit_get_next_type() succeeded, and the error comes from the
visit_type_BlockdevOptions() expecting {}; there is no mention of
the fact that a string would also work).  Now it fails with:
  {"error": {"class": "GenericError",
    "desc": "Invalid parameter type for 'file', expected: BlockdevRef"}}
(the error when the next type doesn't match any expected types for
the overall alternate).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1449033659-25497-5-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:28 +01:00
Eric Blake
7264f5c50c qapi: Convert QType into QAPI built-in enum type
What's more meta than using qapi to define qapi? :)

Convert QType into a full-fledged[*] builtin qapi enum type, so
that a subsequent patch can then use it as the discriminator
type of qapi alternate types.  Fortunately, the judicious use of
'prefix' in the qapi definition avoids churn to the spelling of
the enum constants.

To avoid circular definitions, we have to flip the order of
inclusion between "qobject.h" vs. "qapi-types.h".  Back in commit
28770e0, we had the latter include the former, so that we could
use 'QObject *' for our implementation of 'any'.  But that usage
also works with only a forward declaration, whereas the
definition of QObject requires QType to be a complete type.

[*] The type has to be builtin, rather than declared in
qapi/common.json, because we want to use it for alternates even
when common.json is not included. But since it is the first
builtin enum type, we have to add special cases to qapi-types
and qapi-visit to only emit definitions once, even when two
qapi files are being compiled into the same binary (the way we
already handled builtin list types like 'intList').  We may
need to revisit how multiple qapi files share common types,
but that's a project for another day.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1449033659-25497-4-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:28 +01:00
Eric Blake
1310a3d3bd qobject: Rename qtype_code to QType
The name QType matches our CODING_STYLE conventions for type names
in CamelCase.  It also matches the fact that we are already naming
all the enum members with a prefix of QTYPE, not QTYPE_CODE.  And
doing the rename will also make it easier for the next patch to use
QAPI for providing the enum, which also wants CamelCase type names.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1449033659-25497-3-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:28 +01:00
Eric Blake
55e1819c50 qobject: Simplify QObject
The QObject hierarchy is small enough, and unlikely to grow further
(since we only use it to map to JSON and already cover all JSON
types), that we can simplify things by not tracking a separate
vtable, but just inline the code element of the vtable QType
directly into QObject (renamed to type), and track a separate array
of destroy functions.  We can drop qnull_destroy_obj() in the
process.

The remaining QObject subclasses must export their destructor.

This also has the nice benefit of moving the typename 'QType'
out of the way, so that the next patch can repurpose it for a
nicer name for 'qtype_code'.

The various objects are still the same size (so no change in cache
line pressure), but now have less indirection (although I didn't
bother benchmarking to see if there is a noticeable speedup, as
we don't have hard evidence that this was in a performance hotspot
in the first place).

A future patch could drop the refcnt size to 32 bits for a smaller
struct on 64-bit architectures, if desired (we have limits on the
largest JSON that we are willing to parse, and will probably never
need to take full advantage of a 64-bit refcnt).

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1449033659-25497-2-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:28 +01:00
Eric Blake
d20a580bc0 qapi: Change munging of CamelCase enum values
When munging enum values, the fact that we were passing the entire
prefix + value through camel_to_upper() meant that enum values
spelled with CamelCase could be turned into CAMEL_CASE.  However,
this provides a potential collision (both OneTwo and One-Two would
munge into ONE_TWO) for enum types, when the same two names are
valid side-by-side as QAPI member names.  By changing the generation
of enum constants to always be prefix + '_' + c_name(value,
False).upper(), and ensuring that there are no case collisions (in
the next patches), we no longer have to worry about names that
would be distinct as QAPI members but collide as variant tag names,
without having to think about what munging the heuristics in
camel_to_upper() will actually perform on an enum value.

Making the change will affect enums that did not follow coding
conventions, using 'CamelCase' rather than desired 'lower-case'.

Thankfully, there are only two culprits: InputButton and ErrorClass.
We already tweaked ErrorClass to make it an alias of QapiErrorClass,
where only the alias needs changing rather than the whole tree.  So
the bulk of this change is modifying INPUT_BUTTON_WHEEL_UP to the
new INPUT_BUTTON_WHEELUP (and likewise for WHEELDOWN).  That part
of this commit may later need reverting if we rename the enum
constants from 'WheelUp' to 'wheel-up' as part of moving
x-input-send-event to a stable interface; but at least we have
documentation bread crumbs in place to remind us (commit 513e7cd),
and it matches the fact that SDL constants are also spelled
SDL_BUTTON_WHEELUP.

Suggested by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-27-git-send-email-eblake@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:28 +01:00
Eric Blake
f22a28b898 qapi: Add alias for ErrorClass
The qapi enum ErrorClass is unusual that it uses 'CamelCase' names,
contrary to our documented convention of preferring 'lower-case'.
However, this enum is entrenched in the API; we cannot change
what strings QMP outputs.  Meanwhile, we want to simplify how
c_enum_const() is used to generate enum constants, by moving away
from the heuristics of camel_to_upper() to a more straightforward
c_name(N).upper() - but doing so will rename all of the ErrorClass
constants and cause churn to all client files, where the new names
are aesthetically less pleasing (ERROR_CLASS_DEVICENOTFOUND looks
like we can't make up our minds on whether to break between words).

So as always in computer science, solve the problem by some more
indirection: rename the qapi type to QapiErrorClass, and add a
new enum ErrorClass in error.h whose members are aliases of the
qapi type, but with the spelling expected elsewhere in the tree.
Then, when c_enum_const() changes the munging, we only have to
adjust the one alias spot.

Suggested by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-26-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:28 +01:00
Eric Blake
7549457200 qapi: Remove dead visitor code
Commit cbc95538 removed unused start_handle() and end_handle(),
but forgot to remove their declarations.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-19-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:27 +01:00
Paolo Bonzini
9bada89711 qjson: surprise, allocating 6 QObjects per token is expensive
Replace the contents of the tokens GQueue with a simple struct.  This cuts
the amount of memory allocated by tests/check-qjson from ~500MB to ~20MB,
and the execution time from 600ms to 80ms on my laptop.  Still a lot (some
could be saved by using an intrusive list, such as QSIMPLEQ, instead of
the GQueue), but the savings are already massive and the right thing to
do would probably be to get rid of json-streamer completely.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1448300659-23559-5-git-send-email-pbonzini@redhat.com>
[Straightforwardly rebased on my patches]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-11-26 10:07:07 +01:00
Paolo Bonzini
95385fe9ac qjson: store tokens in a GQueue
Even though we still have the "streamer" concept, the tokens can now
be deleted as they are read.  While doing so convert from QList to
GQueue, since the next step will make tokens not a QObject and we
will have to do the conversion anyway.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1448300659-23559-4-git-send-email-pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-11-26 10:07:07 +01:00
Paolo Bonzini
d2ca7c0b0d qjson: replace QString in JSONLexer with GString
JSONLexer only needs a simple resizable buffer.  json-streamer.c
can allocate memory for each token instead of relying on reference
counting of QStrings.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1448300659-23559-2-git-send-email-pbonzini@redhat.com>
[Straightforwardly rebased on my patches, checkpatch made happy]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-11-26 09:31:22 +01:00
Markus Armbruster
c54616608a qjson: Give each of the six structural chars its own token type
Simplifies things, because we always check for a specific one.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1448486613-17634-6-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-11-26 09:22:54 +01:00
Markus Armbruster
b8d3b1da3c qjson: Spell out some silent assumptions
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1448486613-17634-5-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-11-26 09:18:45 +01:00
Eric Blake
a12a5a1a01 qapi: Simplify error cleanup in test-qmp-*
We have several tests that perform multiple sub-actions that are
expected to fail.  Asserting that an error occurred, then clearing
it up to prepare for the next action, turned into enough
boilerplate that it was sometimes forgotten (for example, a number
of tests added to test-qmp-input-visitor.c in d88f5fd leaked err).
Worse, if an error is not reset to NULL, we risk invalidating
later use of that error (passing a non-NULL err into a function
is generally a bad idea).  Encapsulate the boilerplate into a
single helper function error_free_or_abort(), and consistently
use it.

The new function is added into error.c for use everywhere,
although it is anticipated that testsuites will be the main
client.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-10 08:08:21 +01:00
Eric Blake
cc9f60d4a2 qobject: Protect against use-after-free in qobject_decref()
Adding an assertion to qobject_decref() will ensure that a
programming error causing use-after-free will result in
immediate failure (provided no other thread has started
using the memory) instead of silently attempting to wrap
refcnt around and leaving the problem to potentially bite
later at a harder point to diagnose.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1446791754-23823-4-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-09 16:45:05 +01:00
Pavel Dovgalyuk
0194749ac4 replay: replay blockers for devices
Some devices are not supported by record/replay subsystem.
This patch introduces replay blocker which denies starting record/replay
if such devices are included into the configuration.

Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20150917162512.8676.11367.stgit@PASHA-ISP.def.inno>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
2015-11-06 10:16:03 +01:00
Markus Armbruster
c7c462123c qobject: Drop QObject_HEAD
QObject_HEAD is a macro expanding into the common part of structs that
are sub-types of QObject.  It's always been just QObject base, and
unlikely to change.  Drop the macro, because the code is clearer with
out it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1444918537-18107-2-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-10-29 14:34:44 +01:00
Markus Armbruster
28770e057f qapi: Introduce a first class 'any' type
It's first class, because unlike '**', it actually works, i.e. doesn't
require 'gen': false.

'**' will go away next.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
2015-09-21 09:56:49 +02:00
Markus Armbruster
a29a37b994 error: New error_fatal
Similar to error_abort, but doesn't report where the error was
created, and terminates the process with exit(1) rather than abort().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1441983105-26376-2-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
2015-09-18 14:38:08 +02:00
Eric Blake
50b7b000c9 hmp: Allow for error message hints on HMP
Commits 7216ae3d and d2828429 disabled some error message hints,
all because a change to use modern error reporting meant that the
hint would be output prior to the actual error.  Fix this by making
hints a first-class member of Error.

For example, we are now back to the pleasant:

 $ qemu-system-x86_64 --nodefaults -S --vnc :0 --chardev null,id=,
 qemu-system-x86_64: --chardev null,id=,: Parameter 'id' expects an identifier
 Identifiers consist of letters, digits, '-', '.', '_', starting with a letter.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1441901956-21991-1-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-09-18 14:34:39 +02:00
Markus Armbruster
1e9b65bb1b error: On abort, report where the error was created
This is particularly useful when we abort in error_propagate(),
because there the stack backtrace doesn't lead to where the error was
created.  Looks like this:

    Unexpected error in parse_block_error_action() at .../qemu/blockdev.c:322:
    qemu-system-x86_64: -drive if=none,werror=foo: 'foo' invalid write error action
    Aborted (core dumped)

Note: to get this example output, I monkey-patched drive_new() to pass
&error_abort to blockdev_init().

To keep the error handling boiler plate from growing even more, all
error_setFOO() become macros expanding into error_setFOO_internal()
with additional __FILE__, __LINE__, __func__ arguments.  Not exactly
pretty, but it works.

The macro trickery breaks down when you take the address of an
error_setFOO().  Fortunately, we do that in just one place: qemu-ga's
Windows VSS provider and requester DLL wants to call
error_setg_win32() through a function pointer "to avoid linking glib
to the DLL".  Use error_setg_win32_internal() there.  The use of the
function pointer is already wrapped in a macro, so the churn isn't
bad.

Code size increases by some 35KiB for me (0.7%).  Tolerable.  Could be
less if we passed relative rather than absolute source file names to
the compiler, or forwent reporting __func__.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
2015-09-10 13:48:06 +02:00
Markus Armbruster
edf6f3b335 error: Revamp interface documentation
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-10 13:48:06 +02:00
Markus Armbruster
4463dcb85c error: error_set_errno() is unused, drop
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-10 13:48:06 +02:00
Markus Armbruster
e7cf59e847 qga: Clean up unnecessarily dirty casts
qga_vss_fsfreeze() casts error_set_win32() from

    void (*)(Error **, int, ErrorClass, const char *, ...)

to

    void (*)(void **, int, int, const char *, ...)

The result is later called.  Since the two types are not compatible,
the call is undefined behavior.  It works in practice anyway.

However, there's no real need for trickery here.  Clean it up as
follows:

* Declare struct Error, and fix the first parameter.

* Switch to error_setg_win32().  This gets rid of the troublesome
  ErrorClass parameter.  Requires converting error_setg_win32() from
  macro to function, but that's trivially easy, because this is the
  only user of error_set_win32().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-10 13:48:06 +02:00
Markus Armbruster
a9499ddd82 error: Make error_setg() a function
Saves a tiny amount of code at every call site.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-10 13:48:05 +02:00
Markus Armbruster
d49b683644 qerror: Move #include out of qerror.h
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-06-22 18:20:40 +02:00
Markus Armbruster
4629ed1e98 qerror: Finally unused, clean up
Remove it except for two things in qerror.h:

* Two #include to be cleaned up separately to avoid cluttering this
  patch.

* The QERR_ macros.  Mark as obsolete.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-06-22 18:20:40 +02:00
Markus Armbruster
c6bd8c706a qerror: Clean up QERR_ macros to expand into a single string
These macros expand into error class enumeration constant, comma,
string.  Unclean.  Has been that way since commit 13f59ae.

The error class is always ERROR_CLASS_GENERIC_ERROR since the previous
commit.

Clean up as follows:

* Prepend every use of a QERR_ macro by ERROR_CLASS_GENERIC_ERROR, and
  delete it from the QERR_ macro.  No change after preprocessing.

* Rewrite error_set(ERROR_CLASS_GENERIC_ERROR, ...) into
  error_setg(...).  Again, no change after preprocessing.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-06-22 18:20:40 +02:00
Markus Armbruster
75158ebbe2 qerror: Eliminate QERR_DEVICE_NOT_FOUND
Error classes other than ERROR_CLASS_GENERIC_ERROR should not be used
in new code.  Hiding them in QERR_ macros makes new uses hard to spot.
Fortunately, there's just one such macro left.  Eliminate it with this
coccinelle semantic patch:

    @@
    expression EP, E;
    @@
    -error_set(EP, QERR_DEVICE_NOT_FOUND, E)
    +error_set(EP, ERROR_CLASS_DEVICE_NOT_FOUND, "Device '%s' not found", E)

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-06-22 18:20:39 +02:00
Markus Armbruster
d282842999 qdev-monitor: Convert qbus_find() to Error
As usual, the conversion breaks printing explanatory messages after
the error: actual printing of the error gets delayed, so the
explanations precede rather than follow it.

Pity.  Disable them for now.  See also commit 7216ae3.

While there, eliminate QERR_BUS_NOT_FOUND, and clean up unusual
spelling in the error message.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-06-22 18:20:39 +02:00
Eric Blake
34acbc9522 qobject: Use 'bool' inside qdict
Now that qbool is fixed, let's fix getting and setting a bool
value to a qdict member to also use C99 bool rather than int.

I audited all callers to ensure that the changed return type
will not cause any changed semantics.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Acked-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-06-22 17:40:00 +02:00
Eric Blake
fc48ffc39e qobject: Use 'bool' for qbool
We require a C99 compiler, so let's use 'bool' instead of 'int'
when dealing with boolean values.  There are few enough clients
to fix them all in one pass.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Acked-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-06-22 17:40:00 +02:00
Daniel P. Berrange
2e4450ff43 qom: Make enum string tables const-correct
The enum string table parameters in various QOM/QAPI methods
are declared 'const char *strings[]'. This results in const
warnings if passed a variable that was declared as

   static const char * const strings[] = { .... };

Add the extra const annotation to the parameters, since
neither the string elements, nor the array itself should
ever be modified.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2015-06-19 18:42:18 +02:00
Kevin Wolf
7990d2c99c qdict: Add qdict_{set,copy}_default()
In the block layer functions that determine options for a child block
device, it's a common pattern to either copy options from the parent's
options or to set a default string if the option isn't explicitly set
yet for the child. Provide convenience functions so that it becomes a
one-liner for each option.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-06-12 16:58:06 +02:00
Kevin Wolf
bd50530a9f qdict: Add qdict_array_entries()
This counts the entries in a flattened array in a QDict without
actually splitting the QDict into a QList.

bdrv_open_image() doesn't take a QList, but rather a QDict and a key
prefix string, so this is more convenient for block drivers which have a
dynamically sized list of child nodes (e.g. Quorum) and are to be
converted to using bdrv_open_image() as the standard interface for
opening child nodes.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2015-06-12 16:58:06 +02:00
Markus Armbruster
481b002cc8 qobject: Add a special null QObject
I'm going to fix the JSON parser to recognize null.  The obvious
representation of JSON null as (QObject *)NULL doesn't work, because
the parser already uses it as an error value.  Perhaps we should
change it to free NULL for null, but that's more than I can do right
now.  Create a special null QObject instead.

The existing QDict, QList, and QString all represent something that
is a pointer in C and could therefore be associated with NULL.  But
right now, all three of these sub-types are always non-null once
created, so the new null sentinel object is intentionally unrelated
to them.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-05-11 08:59:07 -04:00
Markus Armbruster
a7c3181628 qobject: Clean up around qtype_code
QTYPE_NONE is a sentinel value.  No QObject has this type code.
Document it properly.

Fix dump_qobject() to abort() on QTYPE_NONE, just like for any other
invalid type code.

Fix to_json() to abort() on all invalid type codes, not just
QTYPE_MAX.

Clean up Property member qtype's type: it's a qtype_code.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-05-11 08:59:07 -04:00
Alberto Garcia
81e5f78a9f block: use bdrv_get_device_or_node_name() in error messages
There are several error messages that identify a BlockDriverState by
its device name. However those errors can be produced in nodes that
don't have a device name associated.

In those cases we should use bdrv_get_device_or_node_name() to fall
back to the node name and produce a more meaningful message. The
messages are also updated to use the more generic term 'node' instead
of 'device'.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 9823a1f0514fdb0692e92868661c38a9e00a12d6.1428485266.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-04-28 15:36:09 +02:00
Alberto Garcia
5b7a580f1f qerror.h: Swap definitions that were not in alphabetical order
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2015-03-10 08:15:33 +03:00
Markus Armbruster
2ee2f1e415 error: New convenience function error_report_err()
I've typed error_report("%s", error_get_pretty(ERR)) too many times
already, and I've fixed too many instances of qerror_report_err(ERR)
to error_report("%s", error_get_pretty(ERR)) as well.  Capture the
pattern in a convenience function.

Since it's almost invariably followed by error_free(), stuff that into
the convenience function as well.

The next patch will put it to use.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-02-18 10:50:43 +01:00
Markus Armbruster
b1ca639184 block: Eliminate silly QERR_ macros used for encryption keys
The QERR_ macros are leftovers from the days of "rich" error objects.
They're used with error_set() and qerror_report(), and expand into the
first *two* arguments.  This trickiness has become pointless.  Clean
up QERR_DEVICE_ENCRYPTED and QERR_DEVICE_NOT_ENCRYPTED.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1422524221-8566-5-git-send-email-armbru@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2015-02-06 11:46:32 -05:00
Markus Armbruster
2e3a0266bd blockdev: Eliminate silly QERR_BLOCK_JOB_NOT_ACTIVE macro
The QERR_ macros are leftovers from the days of "rich" error objects.
They're used with error_set() and qerror_report(), and expand into the
first *two* arguments.  This trickiness has become pointless.  Clean
this one up.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1422524221-8566-3-git-send-email-armbru@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2015-02-06 11:46:32 -05:00
Markus Armbruster
2ad28a088d balloon: Eliminate silly QERR_ macros
The QERR_ macros are leftovers from the days of "rich" error objects.
They're used with error_set() and qerror_report(), and expand into the
first *two* arguments.  This trickiness has become pointless.  Clean
up the balloon ones.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-01-29 10:06:02 +01:00
Markus Armbruster
a6c90cbccd qmp: Eliminate silly QERR_COMMAND_NOT_FOUND macro
The QERR_ macros are leftovers from the days of "rich" error objects.
They're used with error_set() and qerror_report(), and expand into the
first *two* arguments.  This trickiness has become pointless.  Clean
this one up.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-01-29 10:02:18 +01:00
Markus Armbruster
235256a2bd qemu-socket: Eliminate silly QERR_ macros
The QERR_ macros are leftovers from the days of "rich" error objects.
They're used with error_set() and qerror_report(), and expand into the
first *two* arguments.  This trickiness has become pointless.  Clean
up.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-09-26 13:37:06 -04:00
Markus Armbruster
dbe2a7a62a qemu-socket: Polish errors for connect() and listen() failure
connect() doesn't "connect to socket", it connects a socket to an
address and, if it's of type SOCK_STREAM, initiates a connection.
Scratch "to".

listen() does "set socket to listening mode", but it sounds awkward.
Change to "listen on socket".

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-09-26 13:18:38 -04:00
Michael Roth
cee2dedb85 qapi: add visit_start_union and visit_end_union
In some cases an input visitor might bail out on filling out a
struct for various reasons, such as missing fields when running
in strict mode. In the case of a QAPI Union type, this may lead
to cases where the .kind field which encodes the union type
is uninitialized. Subsequently, other visitors, such as the
dealloc visitor, may use this .kind value as if it were
initialized, leading to assumptions about the union type which
in this case may lead to segfaults. For example, freeing an
integer value.

However, we can generally rely on the fact that the always-present
.data void * field that we generate for these union types will
always be NULL in cases where .kind is uninitialized (at least,
there shouldn't be a reason where we'd do this purposefully).

So pass this information on to Visitor implementation via these
optional start_union/end_union interfaces so this information
can be used to guard against the situation above. We will make
use of this information in a subsequent patch for the dealloc
visitor.

Cc: qemu-stable@nongnu.org
Reported-by: Fam Zheng <famz@redhat.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-09-26 13:14:10 -04:00
Peter Lieven
9e7dac7c6c rename parse_enum_option to qapi_enum_parse and make it public
relaxing the license to LGPLv2+ is intentional.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Benoit Canet <benoit.canet@nodalink.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-09-08 11:12:43 +01:00
Wenchao Xia
f882126024 qapi: add event helper functions
This file holds some functions that do not need to be generated.

Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-06-23 11:01:25 -04:00
Peter Maydell
6054d883d6 purge error_is_set()
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Merge remote-tracking branch 'remotes/kraxel/tags/pull-chardev-2' into staging

purge error_is_set()

# gpg: Signature made Wed 21 May 2014 11:43:44 BST using RSA key ID D3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"

* remotes/kraxel/tags/pull-chardev-2:
  error: error_is_set() is finally unused; remove
  char: Explain qmp_chardev_add()'s unusual error handling
  char: Clean up fragile use of error_is_set()
  char: Use return values instead of error_is_set(errp)
  qemu-socket: Clean up inet_connect_opts()

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2014-05-22 18:14:01 +01:00
Markus Armbruster
d2e064a73e error: error_is_set() is finally unused; remove
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-05-21 11:57:58 +02:00
Peter Maydell
ca8c0fab95 Block patches
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Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block patches

# gpg: Signature made Mon 19 May 2014 15:21:14 BST using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-upstream: (22 commits)
  block: optimize zero writes with bdrv_write_zeroes
  blockdev: add a function to parse enum ids from strings
  util: add qemu_iovec_is_zero
  qcow1: Stricter backing file length check
  qcow1: Validate image size (CVE-2014-0223)
  qcow1: Validate L2 table size (CVE-2014-0222)
  qcow1: Check maximum cluster size
  qcow1: Make padding in the header explicit
  curl: Add usage documentation
  curl: Add sslverify option
  curl: Remove broken parsing of options from url
  curl: Fix build when curl_multi_socket_action isn't available
  qemu-iotests: Fix blkdebug in VM drive in 030
  qemu-iotests: Fix core dump suppression in test 039
  iotests: Add test for the JSON protocol
  block: Allow JSON filenames
  check-qdict: Add test for qdict_join()
  qdict: Add qdict_join()
  block: add test for vhdx image created by Disk2VHD
  block: vhdx - account for identical header sections
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2014-05-20 11:57:52 +01:00
Max Reitz
9c52681277 qdict: Add qdict_join()
This function joins two QDicts by absorbing one into the other.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-05-19 11:36:48 +02:00
Markus Armbruster
e2cd0f4fb4 qapi: Replace start_optional()/end_optional() by optional()
Semantics of end_optional() differ subtly from the other end_FOO()
callbacks: when start_FOO() succeeds, the matching end_FOO() gets
called regardless of what happens in between.  end_optional() gets
called only when everything in between succeeds as well.  Entirely
undocumented, like all of the visitor API.

The only user of Visitor Callback end_optional() never did anything,
and was removed in commit 9f9ab46.

I'm about to clean up error handling in the generated visitor code,
and end_optional() is in my way.  No users mean no test cases, and
making non-trivial cleanup transformations without test cases doesn't
strike me as a good idea.

Drop end_optional(), and rename start_optional() to optional().  We
can always go back to a pair of callbacks when we have an actual need.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-15 14:00:45 -04:00
Markus Armbruster
cbc95538ed qapi: Remove unused Visitor callbacks start_handle(), end_handle()
These have never been called or implemented by anything, and their
intended use is undocumented, like all of the visitor API.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-15 14:00:45 -04:00
Markus Armbruster
64dfefed16 error: Consistently name Error ** objects errp, and not err
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-09 09:11:30 -04:00
Markus Armbruster
e940f543ae qmp hmp: Consistently name Error * objects err, and not errp
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-08 14:20:00 -04:00
Cole Robinson
073a341151 error: Remove some unused headers
Makes it a bit clear how the interdependencies work.

Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-04-25 09:19:59 -04:00
Cole Robinson
0b15abfcbc qerror.h: Replace QERR_NOT_SUPPORTED with QERR_UNSUPPORTED
The former is only used twice, the latter is used over 30 times, and
has a nicer error message.

Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-04-25 09:19:59 -04:00
Cole Robinson
f231b88db1 qerror.h: Remove QERR defines that are only used once
Just hardcode them in the callers

Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-04-25 09:19:59 -04:00
Cole Robinson
d73f0beadb qerror.h: Remove unused error classes
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-04-25 09:19:59 -04:00
Wenchao Xia
5d371f41b4 qapi script: do not add "_" for every capitalized char in enum
Now "enum AIOContext" will generate AIO_CONTEXT instead of A_I_O_CONTEXT,
"X86CPU" will generate X86_CPU instead of X86_C_P_U.

Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-03-11 09:07:42 -04:00
Peter Maydell
ac458e121c trivial patches for 2014-03-04
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Merge remote-tracking branch 'remotes/mjt/tags/trivial-patches-2014-03-04' into staging

trivial patches for 2014-03-04

# gpg: Signature made Tue 04 Mar 2014 06:13:56 GMT using RSA key ID 74F0C838
# gpg: Good signature from "Michael Tokarev <mjt@tls.msk.ru>"
# gpg:                 aka "Michael Tokarev <mjt@corpit.ru>"
# gpg:                 aka "Michael Tokarev <mjt@debian.org>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 6EE1 95D1 886E 8FFB 810D  4324 457C E0A0 8044 65C5
#      Subkey fingerprint: E190 8639 3B10 B51B AC2C  8B73 5253 C5AD 74F0 C838

* remotes/mjt/tags/trivial-patches-2014-03-04:
  vl: Remove unneeded include file
  qga: Remove unneeded include file
  qemu-img: Remove unneeded include files
  exec: Remove unneeded include files
  util/iov: Use qemu/sockets.h instead of conditional code
  qjson.h: Remove spurious GCC_FMT_ATTR markup from qobject_from_json() declaration
  tests/test-int128: Don't use __noclone__ attribute on clang
  stubs: Optimize dependencies for gdbstub.c
  tcg: Fix typo in comment (dependancies -> dependencies)
  bswap: Modify prototypes of st[wl]_{le, be}_p (avoid type conversions)
  bswap: Modify prototype of stb_p (avoid type conversions)
  object: Report type in error when not user creatable.
  include/qemu/host-utils.h: Trivial typo: ctz->cto

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2014-03-04 18:12:02 +00:00
Peter Maydell
aa830cdc28 qjson.h: Remove spurious GCC_FMT_ATTR markup from qobject_from_json() declaration
The function qobject_from_json() doesn't actually allow its
argument to be a format string -- it passes a NULL va_list*
to qobject_from_jsonv(), and the parser code will then never
actually interpret %-escape sequences (it tests whether the
va_list pointer is NULL and will stop with a parse error).

The spurious attribute markup causes clang warnings in some
of the test cases where we programmatically construct JSON
to feed to qobject_from_json():

 tests/test-qmp-input-visitor.c:76:35: warning: format string is not a
 string literal (potentially insecure) [-Wformat-security]
    data->obj = qobject_from_json(json_string);
                                  ^~~~~~~~~~~

Remove the incorrect attribute.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2014-03-03 09:45:46 +04:00
Hani Benhabiles
ffe9fe3a25 qerror: Improve QERR_DEVICE_NOT_ACTIVE message
The error message as currently used is confusing as there are no "balloon" or
"spice" devices.

(qemu) balloon 1024
balloon: Device 'balloon' has not been activated

With this patch:

(qemu) balloon 1024
balloon: No balloon device has been activated

Signed-off-by: Hani Benhabiles <hani@linux.com>
Suggested-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-02-28 13:39:25 -05:00
Paolo Bonzini
0b7593e085 qapi: Add human mode to StringOutputVisitor
This will be used by "info qtree".  For numbers it prints both the
decimal and hex values.  For sizes it rounds to the nearest power
of 2^10.  For strings, it puts quotes around the string and separates
NULL and empty string.

Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2014-02-14 21:12:03 +01:00
Max Reitz
05a8c22271 qdict: Add qdict_array_split()
This function splits a QDict consisting of entries prefixed by
incrementally enumerated indices into a QList of QDicts.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-01-22 12:07:17 +01:00
Peter Crosthwaite
5942787183 qerror: Remove assert_no_error()
This is no longer needed, and is obsoleted by error_abort. Remove.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-01-06 15:02:30 -05:00
Peter Crosthwaite
5d24ee70bc error: Add error_abort
Add a special Error * that can be passed to error handling APIs to
signal that any errors are fatal and should abort QEMU. There are two
advantages to this:

- allows for brevity when wishing to assert success of Error **
  accepting APIs. No need for this pattern:
        Error * local_err = NULL;
        api_call(foo, bar, &local_err);
        assert_no_error(local_err);
  This also removes the need for _nofail variants of APIs with
  asserting call sites now reduced to 1LOC.
- SIGABRT happens from within the offending API. When a fatal error
  occurs in an API call (when the caller is asserting sucess) failure
  often means the API itself is broken. With the abort happening in the
  API call now, the stack frames into the call are available at debug
  time. In the assert_no_error scheme the abort happens after the fact.

The exact semantic is that when an error is raised, if the argument
Error ** matches &error_abort, then the abort occurs immediately. The
error messaged is reported.

For error_propagate, if the destination error is &error_abort, then
the abort happens at propagation time.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-01-06 14:01:53 -05:00
Paolo Bonzini
cff8b2c6fc monitor: add object-add (QMP) and object_add (HMP) command
Add two commands that are the monitor counterparts of -object.  The commands
have the same Visitor-based implementation, but use different kinds of
visitors so that the HMP command has a DWIM string-based syntax, while
the QMP variant accepts a stricter JSON-based properties dictionary.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Tested-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-01-06 13:45:47 -05:00
Mark Wu
0106dc4f05 qemu-ga: Extend 'guest-info' command to expose flag 'success-response'
Now we have several qemu-ga commands not returning response on success.
It has been documented in qga/qapi-schema.json already. This patch exposes
the 'success-response' flag by extending 'guest-info' command. With this
change, the clients can handle the command response more flexibly.

Signed-off-by: Mark Wu <wudxw@linux.vnet.ibm.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
*fixed up commit subject
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-10-10 14:52:37 -05:00
Mark Wu
8dc4d915dd qemu-ga: Add interface to traverse the qmp command list by QmpCommand
In the original code, qmp_get_command_list is used to construct
a list of all commands' name. To get the information of all qga
commands, it traverses the name list and search the command info
with its name.  So it can cause O(n^2) in the number of commands.

This patch adds an interface to traverse the qmp command list by
QmpCommand to replace qmp_get_command_list. It can decrease the
complexity from O(n^2) to O(n).

Signed-off-by: Mark Wu <wudxw@linux.vnet.ibm.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
*fix up commit subject
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-10-10 14:52:37 -05:00
Benoît Canet
5726d872f3 qdict: Extract qdict_extract_subqdict
Signed-off-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-25 16:21:28 +02:00
Tomoki Sekiyama
20840d4cfe error: Add error_set_win32 and error_setg_win32
These functions help maintaining homogeneous formatting of error messages
with Windows error code and description (generated by
g_win32_error_message()).

Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-09-09 14:17:57 -05:00
Laszlo Ersek
15a849be10 OptsVisitor: don't try to flatten overlong integer ranges
Prevent mistyped command line options from incurring high memory and CPU
usage at startup. 64K elements in a range should be enough for everyone
(TM).

The OPTS_VISITOR_RANGE_MAX macro is public so that unit tests can
construct corner cases with it.

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2013-08-20 11:52:00 -04:00
Kevin Wolf
f660dc6a2e Implement qdict_flatten()
qdict_flatten(): For each nested QDict with key x, all fields with key y
are moved to this QDict and their key is renamed to "x.y". This operation
is applied recursively for nested QDicts.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2013-07-26 22:01:31 +02:00
Kevin Wolf
69dd62dfd6 qapi: Anonymous unions
The discriminator for anonymous unions is the data type. This allows to
have a union type that allows both of these:

    { 'file': 'my_existing_block_device_id' }
    { 'file': { 'filename': '/tmp/mydisk.qcow2', 'read-only': true } }

Unions like this are specified in the schema with an empty dict as
discriminator. For this example you could take:

    { 'union': 'BlockRef',
      'discriminator': {},
      'data': { 'definition': 'BlockOptions',
                'reference': 'str' } }
    { 'type': 'ExampleObject',
      'data: { 'file': 'BlockRef' } }

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2013-07-26 21:10:11 +02:00
Kevin Wolf
761d524dbc qapi: Add visitor for implicit structs
These can be used when an embedded struct is parsed and members not
belonging to the struct may be present in the input (e.g. parsing a
flat namespace QMP union, where fields from both the base and one
of the alternative types are mixed in the JSON object)

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2013-07-26 20:17:15 +02:00
Luiz Capitulino
dbfbc63734 qerror: drop QERR_OPEN_FILE_FAILED macro
Not used since the last commit.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
2013-06-17 11:01:14 -04:00
Luiz Capitulino
54028d7542 error: add error_setg_file_open() helper
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
2013-06-17 11:01:14 -04:00
Michael Roth
a678e26cbe qapi: pad GenericList value fields to 64 bits
With the introduction of native list types, we now have types such as
int64List where the 'value' field is not a pointer, but the actual
64-bit value.

On 32-bit architectures, this can lead to situations where 'next' field
offset in GenericList does not correspond to the 'next' field in the
types that we cast to GenericList when using the visit_next_list()
interface, causing issues when we attempt to traverse linked list
structures of these types.

To fix this, pad the 'value' field of GenericList and other
schema-defined/native *List types out to 64-bits.

This is less memory-efficient for 32-bit architectures, but allows us to
continue to rely on list-handling interfaces that target GenericList to
simply visitor implementations.

In the future we can improve efficiency by defaulting to using native C
array backends to handle list of non-pointer types, which would be more
memory efficient in itself and allow us to roll back this change.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2013-05-30 09:08:38 -04:00
Michael Tokarev
997aba8e25 remove some double-includes
Some source files #include the same header more than
once for no good reason.  Remove second #includes in
such cases.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-05-18 16:35:12 +04:00
Luiz Capitulino
54d49ac992 qstring: add qstring_get_length()
Long overdue.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
2013-04-05 08:42:29 -04:00
Kevin Wolf
b382bc9a15 Add qdict_clone_shallow()
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-15 16:07:49 +01:00
Paolo Bonzini
1de7afc984 misc: move include files to include/qemu/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:32:39 +01:00
Paolo Bonzini
7b1b5d1913 qapi: move include files to include/qobject/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:31 +01:00