Commit Graph

251 Commits

Author SHA1 Message Date
Markus Armbruster
1f5842487a qapi: Only input visitors can actually fail
The previous few commits have made this more obvious, and removed the
one exception.  Time to clarify the documentation, and drop dead error
checking.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-13-armbru@redhat.com>
2020-04-30 07:26:40 +02:00
Markus Armbruster
8b7ce95b46 qapi: Fix Visitor contract for start_alternate()
The contract demands v->start_alternate() for input and dealloc
visitors, but visit_start_alternate() actually requires it for input
and clone visitors.  Fix the contract, and delete superfluous
qapi_dealloc_start_alternate().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-8-armbru@redhat.com>
2020-04-30 06:51:15 +02:00
Markus Armbruster
8e08bf4ea2 qapi: Assert incomplete object occurs only in dealloc visitor
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-7-armbru@redhat.com>
2020-04-30 06:51:15 +02:00
Markus Armbruster
554d6586ae qapi: Polish prose in visitor.h
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-6-armbru@redhat.com>
2020-04-30 06:51:15 +02:00
Markus Armbruster
c5460d5e19 qapi: Document @errp usage more thoroughly in visitor.h
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-5-armbru@redhat.com>
2020-04-30 06:51:15 +02:00
Markus Armbruster
782586c771 qapi: Fix typo in visit_start_list()'s contract
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-4-armbru@redhat.com>
2020-04-30 06:51:15 +02:00
Markus Armbruster
294c90662a qapi: Fix the virtual walk example in visitor.h's big comment
Call visit_check_list().  Missed in commit a4a1c70dc7 "qapi: Make
input visitors detect unvisited list tails".

Drop an irrelevant error_propagate() while there.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-3-armbru@redhat.com>
2020-04-30 06:51:15 +02:00
Markus Armbruster
3777d36e67 qapi: Belatedly update visitor.h's big comment for QAPI modules
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-2-armbru@redhat.com>
2020-04-30 06:51:15 +02:00
Markus Armbruster
7b1cd1c65a qobject: Eliminate qdict_iter(), use qdict_first(), qdict_next()
qdict_iter() has just three uses and no test coverage.  Replace by
qdict_first(), qdict_next() for more concise code and less type
punning.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200415083048.14339-5-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-04-30 06:51:15 +02:00
Markus Armbruster
2f2ec11179 qobject: Eliminate qlist_iter(), use QLIST_FOREACH_ENTRY() instead
qlist_iter() has just three uses outside tests/.  Replace by
QLIST_FOREACH_ENTRY() for more concise code and less type punning.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200415083048.14339-4-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-04-30 06:51:15 +02:00
Markus Armbruster
64594e2bcc qobject: Clean up QLIST_FOREACH_ENTRY()
QLIST_FOREACH_ENTRY() traverses a tail queue manually.  Use
QTAILQ_FIRST() and QTAILQ_NEXT() instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200415083048.14339-2-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-04-30 06:51:15 +02:00
Marc-André Lureau
f0ccc00be1 qmp: constify QmpCommand and list
Since 0b69f6f72c "qapi: remove
qmp_unregister_command()", the command list can be declared const.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Damien Hedde <damien.hedde@greensocs.com>
Message-Id: <20200316171824.2319695-1-marcandre.lureau@redhat.com>
[Rebased]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-03-17 21:43:12 +01:00
Marc-André Lureau
164c374b75 qstring: add qstring_free()
Similar to g_string_free(), optionally return the underlying char*.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-10-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-24 20:59:13 +01:00
Vladimir Sementsov-Ogievskiy
49fbc7236d error: make Error **errp const where it is appropriate
Mostly, Error ** is for returning error from the function, so the
callee sets it. However these three functions get already filled errp
parameter. They don't change the pointer itself, only change the
internal state of referenced Error object. So we can make it
Error *const * errp, to stress the behavior. It will also help
coccinelle script (in future) to distinguish such cases from common
errp usage.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20191205174635.18758-4-vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message typo fixed]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-12-18 08:36:16 +01:00
Markus Armbruster
81b49004e0 qapi: Make visit_next_list()'s comment less confusing
visit_next_list() returns non-null on success, null on failure.  The
comment's phrasing "until NULL return or error occurs" is needlessly
confusing.  Scratch the "or error occurs" part.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190802122325.16520-1-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2019-09-24 11:03:44 +02:00
Markus Armbruster
abb3d37d0c qapi: Split error.json off common.json
In my "build everything" tree, changing a type in qapi/common.json
triggers a recompile of some 3600 out of 6600 objects (not counting
tests and objects that don't depend on qemu/osdep.h).

One common dependency is QapiErrorClass: it's used only in in
qapi/error.h, which uses nothing else, and is widely included.

Move QapiErrorClass from common.json to new error.json.  Touching
common.json now recompiles only some 2900 objects.

Cc: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-4-armbru@redhat.com>
2019-08-16 13:31:51 +02:00
Marc-André Lureau
0b69f6f72c qapi: remove qmp_unregister_command()
This command is no longer needed, the schema has compile-time
configuration conditions.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190214152251.2073-16-armbru@redhat.com>
2019-02-18 14:44:05 +01:00
Markus Armbruster
a95291007b qapi: Eliminate indirection through qmp_event_get_func_emit()
The qapi_event_send_FOO() functions emit events like this:

    QMPEventFuncEmit emit;

    emit = qmp_event_get_func_emit();
    if (!emit) {
        return;
    }

    qmp = qmp_event_build_dict("FOO");
    [put event arguments into @qmp...]

    emit(QAPI_EVENT_FOO, qmp);

The value of qmp_event_get_func_emit() depends only on the program:

* In qemu-system-FOO, it's always monitor_qapi_event_queue.

* In tests/test-qmp-event, it's always event_test_emit.

* In all other programs, it's always null.

This is exactly the kind of dependence the linker is supposed to
resolve; we don't actually need an indirection.

Note that things would fall apart if we linked more than one QAPI
schema into a single program: each set of qapi_event_send_FOO() uses
its own event enumeration, yet they share a single emit function.
Which takes the event enumeration as an argument.  Which one if
there's more than one?

More seriously: how does this work even now?  qemu-system-FOO wants
QAPIEvent, and passes a function taking that to
qmp_event_set_func_emit().  test-qmp-event wants test_QAPIEvent, and
passes a function taking that to qmp_event_set_func_emit().

It works by type trickery, of course:

    typedef void (*QMPEventFuncEmit)(unsigned event, QDict *dict);

    void qmp_event_set_func_emit(QMPEventFuncEmit emit);

    QMPEventFuncEmit qmp_event_get_func_emit(void);

We use unsigned instead of the enumeration type.  Relies on both
enumerations boiling down to unsigned, which happens to be true for
the compilers we use.

Clean this up as follows:

* Generate qapi_event_send_FOO() that call PREFIX_qapi_event_emit()
  instead of the value of qmp_event_set_func_emit().

* Generate a prototype for PREFIX_qapi_event_emit() into
  qapi-events.h.

* PREFIX_ is empty for qapi/qapi-schema.json, and test_ for
  tests/qapi-schema/qapi-schema-test.json.  It's qga_ for
  qga/qapi-schema.json, and doc-good- for
  tests/qapi-schema/doc-good.json, but those don't define any events.

* Rename monitor_qapi_event_queue() to qapi_event_emit() instead of
  passing it to qmp_event_set_func_emit().  This takes care of
  qemu-system-FOO.

* Rename event_test_emit() to test_qapi_event_emit() instead of
  passing it to qmp_event_set_func_emit().  This takes care of
  tests/test-qmp-event.

* Add a qapi_event_emit() that does nothing to stubs/monitor.c.  This
  takes care of all other programs that link code emitting QMP events.

* Drop qmp_event_set_func_emit(), qmp_event_get_func_emit().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20181218182234.28876-3-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[Commit message typos fixed]
2019-01-24 10:01:05 +01:00
David Hildenbrand
c9fba9de89 qapi: Rewrite string-input-visitor's integer and list parsing
The input visitor has some problems right now, especially
- unsigned type "Range" is used to process signed ranges, resulting in
  inconsistent behavior and ugly/magical code
- uint64_t are parsed like int64_t, so big uint64_t values are not
  supported and error messages are misleading
- lists/ranges of int64_t are accepted although no list is parsed and
  we should rather report an error
- lists/ranges are preparsed using int64_t, making it hard to
  implement uint64_t values or uint64_t lists
- types that don't support lists don't bail out
- visiting beyond the end of a list is not handled properly
- we don't actually parse lists, we parse *sets*: members are sorted,
  and duplicates eliminated

So let's rewrite it by getting rid of usage of the type "Range" and
properly supporting lists of int64_t and uint64_t (including ranges of
both types), fixing the above mentioned issues.

Lists of other types are not supported and will properly report an
error. Virtual walks are now supported.

Tests have to be fixed up:
- Two BUGs were hardcoded that are fixed now
- The string-input-visitor now actually returns a parsed list and not
  an ordered set.

Please note that no users/callers have to be fixed up. Candidates using
visit_type_uint16List() and friends are:
- backends/hostmem.c:host_memory_backend_set_host_nodes()
-- Code can deal with duplicates/unsorted lists
- numa.c::query_memdev()
-- via object_property_get_uint16List(), the list will still be sorted
   and without duplicates (via host_memory_backend_get_host_nodes())
- qapi-visit.c::visit_type_Memdev_members()
- qapi-visit.c::visit_type_NumaNodeOptions_members()
- qapi-visit.c::visit_type_RockerOfDpaGroup_members
- qapi-visit.c::visit_type_RxFilterInfo_members()
-- Not used with string-input-visitor.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20181121164421.20780-7-david@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-12-13 19:10:06 +01:00
Markus Armbruster
4b5766488f error: Fix use of error_prepend() with &error_fatal, &error_abort
From include/qapi/error.h:

  * Pass an existing error to the caller with the message modified:
  *     error_propagate(errp, err);
  *     error_prepend(errp, "Could not frobnicate '%s': ", name);

Fei Li pointed out that doing error_propagate() first doesn't work
well when @errp is &error_fatal or &error_abort: the error_prepend()
is never reached.

Since I doubt fixing the documentation will stop people from getting
it wrong, introduce error_propagate_prepend(), in the hope that it
lures people away from using its constituents in the wrong order.
Update the instructions in error.h accordingly.

Convert existing error_prepend() next to error_propagate to
error_propagate_prepend().  If any of these get reached with
&error_fatal or &error_abort, the error messages improve.  I didn't
check whether that's the case anywhere.

Cc: Fei Li <fli@suse.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20181017082702.5581-2-armbru@redhat.com>
2018-10-19 14:51:34 +02:00
Alberto Garcia
4c9ab1e693 scripts: Remove check-qerror.sh
qerror.h contains leftovers from the now-defunct QError API.

There's only a handful of string macros left, and no one is supposed
to add anything else. The check-qerror.sh script was used to make sure
that all definitions on the qerror.c and qerror.h files were sorted
alphabetically. The former was removed three years ago, and the latter
is now in a different location, so the script doesn't even work (as
a matter of fact the alphabetical order was broken last time someone
added a macro -also in 2015- and no one seemed to notice).

There's no point in fixing this script so let's just remove it.
The rogue macro is also moved to its correct location.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20181017151738.20299-1-berto@igalia.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-10-19 14:40:15 +02:00
Peter Maydell
efd1d5229f Monitor patches for 2018-09-01
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Merge remote-tracking branch 'remotes/armbru/tags/pull-monitor-2018-09-01' into staging

Monitor patches for 2018-09-01

# gpg: Signature made Sat 01 Sep 2018 12:06:52 BST
# gpg:                using RSA key 3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-monitor-2018-09-01:
  monitor: no need to save need_resume
  Revert "qmp: isolate responses into io thread"
  qmp: constify qmp_is_oob()
  monitor: consitify qmp_send_response() QDict argument
  monitor: accept input on resume
  monitor: simplify monitor_qmp_setup_handlers_bh

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-09-24 15:43:33 +01:00
Marc-André Lureau
2aa788f5cb qmp: constify qmp_is_oob()
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180829134043.31706-3-marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-08-30 16:08:47 +02:00
Peter Xu
3ab72385b2 qapi: Drop qapi_event_send_FOO()'s Error ** argument
The generated qapi_event_send_FOO() take an Error ** argument.  They
can't actually fail, because all they do with the argument is passing it
to functions that can't fail: the QObject output visitor, and the
@qmp_emit callback, which is either monitor_qapi_event_queue() or
event_test_emit().

Drop the argument, and pass &error_abort to the QObject output visitor
and @qmp_emit instead.

Suggested-by: Eric Blake <eblake@redhat.com>
Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180815133747.25032-4-peterx@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message rewritten, update to qapi-code-gen.txt corrected]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-08-28 18:21:38 +02:00
Markus Armbruster
37aded92c2 json: Update references to RFC 7159 to RFC 8259
RFC 8259 (December 2017) obsoletes RFC 7159 (March 2014).

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180823164025.12553-59-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2018-08-24 20:27:14 +02:00
Markus Armbruster
86cdf9ec8d json: Clean up headers
The JSON parser has three public headers, json-lexer.h, json-parser.h,
json-streamer.h.  They all contain stuff that is of no interest
outside qobject/json-*.c.

Collect the public interface in include/qapi/qmp/json-parser.h, and
everything else in qobject/json-parser-int.h.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-54-armbru@redhat.com>
2018-08-24 20:26:37 +02:00
Markus Armbruster
812ce33ead qobject: Drop superfluous includes of qemu-common.h
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-53-armbru@redhat.com>
2018-08-24 20:26:37 +02:00
Markus Armbruster
abe7c2067c json: Make JSONToken opaque outside json-parser.c
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-52-armbru@redhat.com>
2018-08-24 20:26:37 +02:00
Markus Armbruster
a2731e08ee json: Unbox tokens queue in JSONMessageParser
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-51-armbru@redhat.com>
2018-08-24 20:26:37 +02:00
Markus Armbruster
f9277915ee json: Fix streamer not to ignore trailing unterminated structures
json_message_process_token() accumulates tokens until it got the
sequence of tokens that comprise a single JSON value (it counts curly
braces and square brackets to decide).  It feeds those token sequences
to json_parser_parse().  If a non-empty sequence of tokens remains at
the end of the parse, it's silently ignored.  check-qjson.c cases
unterminated_array(), unterminated_array_comma(), unterminated_dict(),
unterminated_dict_comma() demonstrate this bug.

Fix as follows.  Introduce a JSON_END_OF_INPUT token.  When the
streamer receives it, it feeds the accumulated tokens to
json_parser_parse().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-46-armbru@redhat.com>
2018-08-24 20:26:37 +02:00
Markus Armbruster
84a56f38b2 json: Pass lexical errors and limit violations to callback
The callback to consume JSON values takes QObject *json, Error *err.
If both are null, the callback is supposed to make up an error by
itself.  This sucks.

qjson.c's consume_json() neglects to do so, which makes
qobject_from_json() null instead of failing.  I consider that a bug.

The culprit is json_message_process_token(): it passes two null
pointers when it runs into a lexical error or a limit violation.  Fix
it to pass a proper Error object then.  Update the callbacks:

* monitor.c's handle_qmp_command(): the code to make up an error is
  now dead, drop it.

* qga/main.c's process_event(): lumps the "both null" case together
  with the "not a JSON object" case.  The former is now gone.  The
  error message "Invalid JSON syntax" is misleading for the latter.
  Improve it to "Input must be a JSON object".

* qobject/qjson.c's consume_json(): no update; check-qjson
  demonstrates qobject_from_json() now sets an error on lexical
  errors, but still doesn't on some other errors.

* tests/libqtest.c's qmp_response(): the Error object is now reliable,
  so use it to improve the error message.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-40-armbru@redhat.com>
2018-08-24 20:26:37 +02:00
Markus Armbruster
2cbd15aa6f json: Treat unwanted interpolation as lexical error
The JSON parser optionally supports interpolation.  The lexer
recognizes interpolation tokens unconditionally.  The parser rejects
them when interpolation is disabled, in parse_interpolation().
However, it neglects to set an error then, which can make
json_parser_parse() fail without setting an error.

Move the check for unwanted interpolation from the parser's
parse_interpolation() into the lexer's finite state machine.  When
interpolation is disabled, '%' is now handled like any other
unexpected character.

The next commit will improve how such lexical errors are handled.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-39-armbru@redhat.com>
2018-08-24 20:26:37 +02:00
Markus Armbruster
61030280ca json: Rename token JSON_ESCAPE & friends to JSON_INTERP
The JSON parser optionally supports interpolation.  The code calls it
"escape".  Awkward, because it uses the same term for escape sequences
within strings.  The latter usage is consistent with RFC 8259 "The
JavaScript Object Notation (JSON) Data Interchange Format" and ISO C.
Call the former "interpolation" instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-38-armbru@redhat.com>
2018-08-24 20:26:37 +02:00
Markus Armbruster
62815d85ae json: Redesign the callback to consume JSON values
The classical way to structure parser and lexer is to have the client
call the parser to get an abstract syntax tree, the parser call the
lexer to get the next token, and the lexer call some function to get
input characters.

Another way to structure them would be to have the client feed
characters to the lexer, the lexer feed tokens to the parser, and the
parser feed abstract syntax trees to some callback provided by the
client.  This way is more easily integrated into an event loop that
dispatches input characters as they arrive.

Our JSON parser is kind of between the two.  The lexer feeds tokens to
a "streamer" instead of a real parser.  The streamer accumulates
tokens until it got the sequence of tokens that comprise a single JSON
value (it counts curly braces and square brackets to decide).  It
feeds those token sequences to a callback provided by the client.  The
callback passes each token sequence to the parser, and gets back an
abstract syntax tree.

I figure it was done that way to make a straightforward recursive
descent parser possible.  "Get next token" becomes "pop the first
token off the token sequence".  Drawback: we need to store a complete
token sequence.  Each token eats 13 + input characters + malloc
overhead bytes.

Observations:

1. This is not the only way to use recursive descent.  If we replaced
   "get next token" by a coroutine yield, we could do without a
   streamer.

2. The lexer reports errors by passing a JSON_ERROR token to the
   streamer.  This communicates the offending input characters and
   their location, but no more.

3. The streamer reports errors by passing a null token sequence to the
   callback.  The (already poor) lexical error information is thrown
   away.

4. Having the callback receive a token sequence duplicates the code to
   convert token sequence to abstract syntax tree in every callback.

5. Known bug: the streamer silently drops incomplete token sequences.

This commit rectifies 4. by lifting the call of the parser from the
callbacks into the streamer.  Later commits will address 3. and 5.

The lifting removes a bug from qjson.c's parse_json(): it passed a
pointer to a non-null Error * in certain cases, as demonstrated by
check-qjson.c.

json_parser_parse() is now unused.  It's a stupid wrapper around
json_parser_parse_err().  Drop it, and rename json_parser_parse_err()
to json_parser_parse().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-35-armbru@redhat.com>
2018-08-24 20:26:37 +02:00
Markus Armbruster
037f244088 json: Have lexer call streamer directly
json_lexer_init() takes the function to process a token as an
argument.  It's always json_message_process_token().  Makes the code
harder to understand for no actual gain.  Drop the indirection.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-34-armbru@redhat.com>
2018-08-24 20:26:37 +02:00
Marc-André Lureau
7c1e1d5481 json: remove useless return value from lexer/parser
The lexer always returns 0 when char feeding. Furthermore, none of the
caller care about the return value.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20180326150916.9602-10-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180823164025.12553-32-armbru@redhat.com>
2018-08-24 20:26:37 +02:00
Markus Armbruster
2d36e84304 qobject: qobject_from_jsonv() is dangerous, hide it away
qobject_from_jsonv() takes ownership of %p arguments.  On failure, we
can't generally know whether we failed before or after %p, so
ownership becomes indeterminate.  To avoid leaks, callers passing %p
must terminate on error, e.g. by passing &error_abort.  Trap for the
unwary; document and give the function internal linkage.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180806065344.7103-11-armbru@redhat.com>
2018-08-16 08:42:06 +02:00
Markus Armbruster
4ff184689b qobject: New qobject_from_vjsonf_nofail(), qdict_from_vjsonf_nofail()
Every printf()-like function sooner or later needs its vprintf()-like
buddy.  The next commit will need qobject_from_jsonf_nofail()'s buddy,
and qdict_from_jsonf_nofail()'s buddy will be used later in this
series.  Add both.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180806065344.7103-8-armbru@redhat.com>
2018-08-16 08:42:06 +02:00
Markus Armbruster
6ce80fd803 qobject: Replace qobject_from_jsonf() by qobject_from_jsonf_nofail()
Commit ab45015a96 "qobject: Let qobject_from_jsonf() fail instead of
abort" fails to accomplish its stated aim: the function can still
abort due to its use of &error_abort.

Its rationale for letting it fail is that all remaining users cope
fine with failure.  Well, they're just fine with aborting, too; it's
what they do on failure.

Simply reverting the broken commit would bring back the unfortunate
asymmetry between qobject_from_jsonf() and qobject_from_jsonv(): one
aborts, the other returns null.  So also rename it to
qobject_from_jsonf_nofail().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180806065344.7103-7-armbru@redhat.com>
2018-08-16 08:42:06 +02:00
liujunjie
ad63c549ec qstring: Fix qstring_from_substr() not to provoke int overflow
qstring_from_substr() parameters @start and @end are of type int.
blkdebug_parse_filename(), blkverify_parse_filename(), nbd_parse_uri(),
and qstring_from_str() pass @end values of type size_t or ptrdiff_t.
Values exceeding INT_MAX get truncated, with possibly disastrous
results.

Such huge substrings seem unlikely, but we found one in a core dump,
where "info tlb" executed via QMP's human-monitor-command apparently
produced 35 GiB of output.

Fix by changing the parameters size_t.

Signed-off-by: liujunjie <liujunjie23@huawei.com>
Message-Id: <20180724134339.17832-1-liujunjie23@huawei.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-07-28 09:09:58 +02:00
Markus Armbruster
d43b16945a qmp: Use QDict * instead of QObject * for response objects
By using the more specific type, we get fewer downcasts.  The
downcasts are safe, but not obviously so, at least not locally.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180703085358.13941-24-armbru@redhat.com>
2018-07-03 23:18:56 +02:00
Markus Armbruster
cee32796ca qmp: De-duplicate error response building
All callers of qmp_build_error_object() duplicate the code to wrap it
in a response object.  Replace it by qmp_error_response() that
captures the duplicated code, including error_free().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180703085358.13941-23-armbru@redhat.com>
2018-07-03 23:18:56 +02:00
Markus Armbruster
a193352ff9 qobject: New qdict_from_jsonf_nofail()
Many uses of qobject_from_jsonf() convert JSON objects.  Create new
convenience function qdict_from_jsonf_nofail() that includes the
conversion to QDict.  The next few commits will put it to use.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180703085358.13941-22-armbru@redhat.com>
2018-07-03 23:18:56 +02:00
Markus Armbruster
69240fe62d qmp: Don't let malformed in-band commands jump the queue
handle_qmp_command() reports certain errors right away.  This is wrong
when OOB is enabled, because the errors can "jump the queue" then, as
the previous commit demonstrates.

To fix, we need to delay errors until dispatch.  Do that for semantic
errors, mostly by reverting ill-advised parts of commit cf869d5317
"qmp: support out-of-band (oob) execution".  Bonus: doesn't run
qmp_dispatch_check_obj() twice, once in handle_qmp_command(), and
again in do_qmp_dispatch().  That's also due to commit cf869d5317.

The next commit will fix queue jumping for syntax errors.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180703085358.13941-18-armbru@redhat.com>
2018-07-03 23:18:56 +02:00
Markus Armbruster
674ed7228f qmp qemu-ga: Fix qemu-ga not to accept "control"
Commit cf869d5317 "qmp: support out-of-band (oob) execution"
accidentally made qemu-ga accept and ignore "control".  Fix that.

Out-of-band execution in a monitor that doesn't support it now fails
with

    {"error": {"class": "GenericError", "desc": "QMP input member 'control' is unexpected"}}

instead of

    {"error": {"class": "GenericError", "desc": "Please enable out-of-band first for the session during capabilities negotiation"}}

The old description is suboptimal when out-of-band cannot not be
enabled, or the command doesn't support out-of-band execution.

The new description is a bit unspecific, but it'll do.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180703085358.13941-12-armbru@redhat.com>
2018-07-03 23:18:56 +02:00
Max Reitz
609f45ea95 block: Add block-specific QDict header
There are numerous QDict functions that have been introduced for and are
used only by the block layer.  Move their declarations into an own
header file to reflect that.

While qdict_extract_subqdict() is in fact used outside of the block
layer (in util/qemu-config.c), it is still a function related very
closely to how the block layer works with nested QDicts, namely by
sometimes flattening them.  Therefore, its declaration is put into this
header as well and util/qemu-config.c includes it with a comment stating
exactly which function it needs.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20180509165530.29561-7-mreitz@redhat.com>
[Copyright note tweaked, superfluous includes dropped]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-15 14:49:44 +02:00
Igor Mammedov
d6fe3d02e9 qapi: introduce new cmd option "allow-preconfig"
New option will be used to allow commands, which are prepared/need
to run, during preconfig state. Other commands that should be able
to run in preconfig state, should be amended to not expect machine
in initialized state or deal with it.

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

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

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

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <1526057503-39287-1-git-send-email-imammedo@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[ehabkost: Changed "since 2.13" to "since 3.0"]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2018-05-30 13:19:09 -03:00
Marc-André Lureau
f5a74a5a50 qobject: Modify qobject_ref() to return obj
For convenience and clarity, make it possible to call qobject_ref() at
the time when the reference is associated with a variable, or
argument, by making qobject_ref() return the same pointer as given.
Use that to simplify the callers.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180419150145.24795-5-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Useless change to qobject_ref_impl() dropped, commit message improved
slightly]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-05-04 08:27:53 +02:00
Marc-André Lureau
cb3e7f08ae qobject: Replace qobject_incref/QINCREF qobject_decref/QDECREF
Now that we can safely call QOBJECT() on QObject * as well as its
subtypes, we can have macros qobject_ref() / qobject_unref() that work
everywhere instead of having to use QINCREF() / QDECREF() for QObject
and qobject_incref() / qobject_decref() for its subtypes.

The replacement is mechanical, except I broke a long line, and added a
cast in monitor_qmp_cleanup_req_queue_locked().  Unlike
qobject_decref(), qobject_unref() doesn't accept void *.

Note that the new macros evaluate their argument exactly once, thus no
need to shout them.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180419150145.24795-4-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Rebased, semantic conflict resolved, commit message improved]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-05-04 08:27:53 +02:00
Marc-André Lureau
3d3eacaecc qobject: use a QObjectBase_ struct
By moving the base fields to a QObjectBase_, QObject can be a type
which also has a 'base' field. This allows writing a generic QOBJECT()
macro that will work with any QObject type, including QObject
itself. The container_of() macro ensures that the object to cast has a
QObjectBase_ base field, giving some type safety guarantees. QObject
must have no members but QObjectBase_ base, or else QOBJECT() breaks.

QObjectBase_ is not a typedef and uses a trailing underscore to make
it obvious it is not for normal use and to avoid potential abuse.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180419150145.24795-3-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-05-04 08:27:53 +02:00