Commit graph

64 commits

Author SHA1 Message Date
Markus Armbruster 5aceeac04d qapi: Enforce struct member naming rules
Struct members, including command arguments, event data, and union
inline base members, should use '-', not '_'.  Enforce this.  Fix the
fixable offenders (all in tests/), and add the remainder to pragma
member-name-exceptions.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210323094025.3569441-27-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2021-03-23 22:31:43 +01:00
Markus Armbruster 05ebf841ef qapi: Enforce command naming rules
Command names should be lower-case.  Enforce this.  Fix the fixable
offenders (all in tests/), and add the remainder to pragma
command-name-exceptions.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210323094025.3569441-25-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2021-03-23 22:31:05 +01:00
Markus Armbruster b86df37478 qapi: Rename pragma *-whitelist to *-exceptions
Rename pragma returns-whitelist to command-returns-exceptions, and
name-case-whitelist to member-name-case-exceptions.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210323094025.3569441-20-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2021-03-23 22:31:05 +01:00
Markus Armbruster c4cdf54cff docs/devel/qapi-code-gen: Fix up examples
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201027121026.3025930-1-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2020-11-09 09:07:59 +01:00
Kevin Wolf bb4b9ead95 hmp: Add support for coroutine command handlers
Often, QMP command handlers are not only called to handle QMP commands,
but also from a corresponding HMP command handler. In order to give them
a consistent environment, optionally run HMP command handlers in a
coroutine, too.

The implementation is a lot simpler than in QMP because for HMP, we
still block the VM while the coroutine is running.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20201005155855.256490-11-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-10-09 07:08:20 +02:00
Kevin Wolf 04f22362f1 qapi: Add a 'coroutine' flag for commands
This patch adds a new 'coroutine' flag to QMP command definitions that
tells the QMP dispatcher that the command handler is safe to be run in a
coroutine.

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

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20201005155855.256490-9-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-10-09 07:08:19 +02:00
Peter Maydell 55ec69f8b1 docs/devel/qapi-code-gen.txt: Update to new rST backend conventions
Update the documentation of QAPI document comment syntax to match
the new rST backend requirements. The principal changes are:
 * whitespace is now significant, and multiline definitions
   must have their second and subsequent lines indented to
   match the first line
 * general rST format markup is permitted, not just the small
   set of markup the old texinfo generator handled. For most
   things (notably bulleted and itemized lists) the old format
   was the same as rST is.
 * Specific things that might trip people up:
   - instead of *bold* and _italic_ rST has **bold** and *italic*
   - lists need a preceding and following blank line
   - a lone literal '*' will need to be backslash-escaped to
     avoid a rST syntax error
 * the old leading '|' for example (literal text) blocks is
   replaced by the standard rST '::' literal block.
 * we support arbitrary levels of sub- and sub-sub-heading, not
   just a main and sub-heading like the old texinfo generator
 * lists can now be nested

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20200925162316.21205-18-peter.maydell@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message improved slightly]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-09-29 17:55:39 +02:00
Peter Maydell a69a6d4b4d scripts/qapi/parser.py: improve doc comment indent handling
Make the handling of indentation in doc comments more sophisticated,
so that when we see a section like:

Notes: some text
       some more text
          indented line 3

we save it for the doc-comment processing code as:

some text
some more text
   indented line 3

and when we see a section with the heading on its own line:

Notes:

some text
some more text
   indented text

we also accept that and save it in the same form.

If we detect that the comment document text is not indented as much
as we expect it to be, we throw a parse error.  (We don't complain
about over-indented sections, because for rST this can be legitimate
markup.)

The golden reference for the doc comment text is updated to remove
the two 'wrong' indents; these now form a test case that we correctly
stripped leading whitespace from an indented multi-line argument
definition.

We update the documentation in docs/devel/qapi-code-gen.txt to
describe the new indentation rules.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20200925162316.21205-6-peter.maydell@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Whitespace between sentences tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-09-29 17:55:39 +02:00
Markus Armbruster d98884b75d qapi: Reject section markup in definition documentation
Section markup in definition documentation makes no sense and can
produce invalid Texinfo.  Reject.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200320091805.5585-2-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-09-07 16:35:16 +02:00
Daniel P. Berrangé 221db5daf6 qapi: enable use of g_autoptr with QAPI types
Currently QAPI generates a type and function for free'ing it:

  typedef struct QCryptoBlockCreateOptions QCryptoBlockCreateOptions;
  void qapi_free_QCryptoBlockCreateOptions(QCryptoBlockCreateOptions *obj);

This is used in the traditional manner:

  QCryptoBlockCreateOptions *opts = NULL;

  opts = g_new0(QCryptoBlockCreateOptions, 1);

  ....do stuff with opts...

  qapi_free_QCryptoBlockCreateOptions(opts);

Since bumping the min glib to 2.48, QEMU has incrementally adopted the
use of g_auto/g_autoptr. This allows the compiler to run a function to
free a variable when it goes out of scope, the benefit being the
compiler can guarantee it is freed in all possible code ptahs.

This benefit is applicable to QAPI types too, and given the seriously
long method names for some qapi_free_XXXX() functions, is much less
typing. This change thus makes the code generator emit:

 G_DEFINE_AUTOPTR_CLEANUP_FUNC(QCryptoBlockCreateOptions,
                              qapi_free_QCryptoBlockCreateOptions)

The above code example now becomes

  g_autoptr(QCryptoBlockCreateOptions) opts = NULL;

  opts = g_new0(QCryptoBlockCreateOptions, 1);

  ....do stuff with opts...

Note, if the local pointer needs to live beyond the scope holding the
variable, then g_steal_pointer can be used. This is useful to return the
pointer to the caller in the success codepath, while letting it be freed
in all error codepaths.

  return g_steal_pointer(&opts);

The crypto/block.h header needs updating to avoid symbol clash now that
the g_autoptr support is a standard QAPI feature.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200723153845.2934357-1-berrange@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-09-03 09:38:36 +02:00
Markus Armbruster cdd2b228b9 qapi: Smooth visitor error checking in generated code
Use visitor functions' return values to check for failure.  Eliminate
error_propagate() that are now unnecessary.  Delete @err that are now
unused.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-41-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster 012d4c96e2 qapi: Make visitor functions taking Error ** return bool, not void
See recent commit "error: Document Error API usage rules" for
rationale.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-18-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster 2061487bdb qapi: Disallow qmp_marshal_FOO(NULL, ...)
For QMP commands without arguments, gen_marshal() laboriously
generates a qmp_marshal_FOO() that copes with null @args.  Turns
there's just one caller that passes null instead of an empty QDict.
Adjust that caller, and simplify gen_marshal().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200424084338.26803-15-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-04-30 07:26:41 +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 f965e8fea6 qapi: New special feature flag "deprecated"
Unlike regular feature flags, the new special feature flag
"deprecated" is recognized by the QAPI generator.  For now, it's only
permitted with commands, events, and struct members.  It will be put
to use shortly.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200317115459.31821-26-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[Doc typo fixed]
2020-03-17 21:42:47 +01:00
Markus Armbruster 84ab008687 qapi: Add feature flags to struct members
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200317115459.31821-21-armbru@redhat.com>
2020-03-17 21:25:47 +01:00
Markus Armbruster 013b4efc9b qapi: Add feature flags to remaining definitions
In v4.1.0, we added feature flags just to struct types (commit
6a8c0b5102^..f3ed93d545), to satisfy an immediate need (commit
c9d4070991 "file-posix: Add dynamic-auto-read-only QAPI feature").  In
v4.2.0, we added them to commands (commit 23394b4c39 "qapi: Add
feature flags to commands") to satisfy another immediate need (commit
d76744e65e "qapi: Allow introspecting fix for savevm's cooperation
with blockdev").

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

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200317115459.31821-13-armbru@redhat.com>
2020-03-17 19:58:34 +01:00
Markus Armbruster 86014c64f9 docs/devel/qapi-code-gen: Document 'features' introspection
Commit 6a8c0b5102 "qapi: Add feature flags to struct types" neglected
to update section "Client JSON Protocol introspection", and commit
23394b4c39 "qapi: Add feature flags to commands" didn't either.  Make
up for that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200317115459.31821-5-armbru@redhat.com>
2020-03-17 19:58:34 +01:00
Markus Armbruster ad52292ea1 docs/devel/qapi-code-gen: Clarify allow-oob introspection
Mention SchemaInfo variant member "allow-oob" defaults to false.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200317115459.31821-4-armbru@redhat.com>
2020-03-17 19:58:34 +01:00
Markus Armbruster 942ab6865a docs/devel/qapi-code-gen: Fix typo in grammar
An ALTERNATIVE's value can only be a type name.  Arrays are not
supported, yet.  The text gets it right: "The form STRING is shorthand
for { 'type': STRING }."  The grammar doesn't.  Fix it.

Fixes: b6c37ebaaf
Reported-by: John Snow <jsnow@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200309142638.19988-1-armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2020-03-17 17:34:21 +01:00
Markus Armbruster 00ca24ff9e qapi: Generate command registration stuff into separate files
Having to include qapi-commands.h just for qmp_init_marshal() is
suboptimal.  Generate it into separate files.  This lets
monitor/misc.c, qga/main.c, and the generated qapi-commands-FOO.h
include less.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20191120182551.23795-4-armbru@redhat.com>
[Typos in docs/devel/qapi-code-gen.txt fixed]
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-01-14 11:01:58 +01:00
Peter Krempa 23394b4c39 qapi: Add feature flags to commands
Similarly to features for struct types introduce the feature flags also
for commands. This will allow notifying management layers of fixes and
compatible changes in the behaviour of a command which may not be
detectable any other way.

The changes were heavily inspired by commit 6a8c0b5102.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20191018081454.21369-3-armbru@redhat.com>
2019-10-22 13:54:13 +02:00
Markus Armbruster 9d55380b5a qapi: Remove null from schema language
We represent the parse tree as OrderedDict.  We fetch optional dict
members with .get().  So far, so good.

We represent null literals as None.  .get() returns None both for
"absent" and for "present, value is the null literal".  Uh-oh.

Test features-if-invalid exposes this bug: "'if': null" is
misinterpreted as absent "if".

We added null to the schema language to "allow [...] an explicit
default value" (commit e53188ada5 "qapi: Allow true, false and null in
schema json", v2.4.0).  Hasn't happened; null is still unused except
as generic invalid value in tests/.

To fix, we'd have to replace .get() by something more careful, or
represent null differently.  Feasible, but we got more and bigger fish
to fry right now.  Remove the null literal from the schema language.
Replace null in tests by another invalid value.

Test features-if-invalid now behaves as it should.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190914153506.2151-10-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2019-09-24 14:07:23 +02:00
Markus Armbruster b6c37ebaaf docs/devel/qapi-code-gen: Improve QAPI schema language doc
We document the language by giving patterns of valid JSON objects.
The patterns contain placeholders we don't define anywhere; their
names have to speak for themselves.  I guess they do, but I'd prefer a
bit more rigor.  Provide a grammar instead, and rework the text
accordingly.

Documentation for QAPI schema conditionals (commit 967c885108,
6cc32b0e14, 87adbbffd4..3e270dcacc) and feature flags (commit
6a8c0b5102) was bolted on.  The sections documenting types, commands
and events don't mention them.  Section "Features" and "Configuring
the schema" then provide additional syntax for types, commands and
events.  I hate that.  Fix the sections documenting types, commands
and events to provide accurate syntax, and point to "Features" and
"Configuring the schema" for details.

We talk about "(top-level) expressions other than include and pragma".
Adopt more convenient terminology: a (top-level) expression is either
a directive (include or pragma) or a definition (anything else).

Avoid the terms "dictionary" and "key".  Stick to JSON terminology
"object" and "member name" instead.

While there, make spacing more consistent.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190913201349.24332-16-armbru@redhat.com>
2019-09-24 14:07:22 +02:00
Markus Armbruster 634c82c163 docs/devel/qapi-code-gen: Rewrite introduction to schema
The introduction to the QAPI schema is somewhat rambling.  Rewrite for
clarity.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190913201349.24332-15-armbru@redhat.com>
2019-09-24 14:07:22 +02:00
Markus Armbruster ab76bc2794 docs/devel/qapi-code-gen: Rewrite compatibility considerations
We have some compatibility advice buried in sections "Enumeration
types" and "Struct types".  Compatibility is actually about commands
and events.  It devolves to the types used there.  All kinds of types,
not just enumerations and structs.

Replace the existing advice by a new section "Compatibility
considerations".

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190913201349.24332-14-armbru@redhat.com>
[Squash in paragraph on invisible schema changes, as per Eric's review]
2019-09-24 14:07:22 +02:00
Markus Armbruster f5821f5262 docs/devel/qapi-code-gen: Reorder sections for readability
Section "QMP/Guest agent schema" starts with a brief introduction,
then subsection "Comments", then subsection "Schema overview" (more
elaborate introduction), and only then talks about schema entities
like types, commands, and so forth.

Subsection "Comments" is long and tiring: almost 500 words, mostly
about doc comments.  Move the doc comment part to its own subsection
"Documentation comments" at the very end of "QMP/Guest agent schema".

Subsection "Schema overview" explains naming rules at considerable
length: 250 words.  Move this part to its own subsection "Naming rules
and reserved names" right after the subsections on schema entities.

Subsection "Enumeration types" is wedged between "Struct types" and
"Union types".  Move it before "Struct types".

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190913201349.24332-13-armbru@redhat.com>
2019-09-24 14:07:22 +02:00
Markus Armbruster 0ced9531f1 qapi: Permit omitting all flat union branches
Absent flat union branches default to the empty struct (since commit
800877bb16 "qapi: allow empty branches in flat unions").  But an
attempt to omit all of them is rejected with "Union 'FOO' has no
branches".  Harmless oddity, but it's easy to avoid, so do that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190913201349.24332-11-armbru@redhat.com>
[Commit message typo fixed]
2019-09-24 14:07:22 +02:00
Markus Armbruster e24fe238e2 docs/devel/qapi-code-gen: Minor specification fixes
The specification claims "Each expression that isn't an include
directive may be preceded by a documentation block", but the code also
rejects them for pragma directives.  The code is correct.  Fix the
specification.

The specification reserves member names starting with 'has_', but the
code also reserves name 'u'.  Fix the specification.

The specification claims "The string 'max' is not allowed as an enum
value".  Untrue.  Fix the specification.  While there, delete the
naming advice, because it's redundant with the naming rules in section
"Schema overview"

The specification claims "No branch of the union can be named 'max',
as this would collide with the implicit enum".  Untrue.  Fix the
specification.

The specification claims "It is not allowed to name an event 'MAX',
since the generator also produces a C enumeration of all event names
with a generated _MAX value at the end."  Untrue.  Fix the
specification.

The specification claims "All branches of the union must be complex
types", but the code permits only struct types.  The code is correct.
Fix the specification.

The specification claims a command's return type "must be the string
name of a complex or built-in type, a one-element array containing the
name of a complex or built-in type" unless the command is in pragma
'returns-whitelist'.  The code does not permit built-in types.  Fix
the specification.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190913201349.24332-5-armbru@redhat.com>
2019-09-24 14:07:22 +02:00
Markus Armbruster b22e86585b qapi: Drop support for boxed alternate arguments
Commands and events can define their argument type inline (default) or
by referring to another type ('boxed': true, since commit c818408e44
"qapi: Implement boxed types for commands/events", v2.7.0).  The
unboxed inline definition is an (anonymous) struct type.  The boxed
type may be a struct, union, or alternate type.

The latter is problematic: docs/interop/qemu-spec.txt requires the
value of the 'data' key to be a json-object, but any non-degenerate
alternate type has at least one branch that isn't.

Fortunately, we haven't made use of alternates in this context outside
tests/.  Drop support for them.

QAPISchemaAlternateType.is_empty() is now unused.  Drop it, too.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190913201349.24332-4-armbru@redhat.com>
2019-09-24 14:07:22 +02:00
Kevin Wolf 6a8c0b5102 qapi: Add feature flags to struct types
Sometimes, the behaviour of QEMU changes without a change in the QMP
syntax (usually by allowing values or operations that previously
resulted in an error). QMP clients may still need to know whether
they can rely on the changed behavior.

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

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

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

Introspection information then looks like this:

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

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

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20190606153803.5278-2-armbru@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-06-12 18:34:26 +02:00
Markus Armbruster 5d75648b56 qapi: Generate QAPIEvent stuff into separate files
Having to include qapi-events.h just for QAPIEvent is suboptimal, but
quite tolerable now.  It'll become problematic when we have events
conditional on the target, because then qapi-events.h won't be usable
from target-independent code anymore.  Avoid that by generating it
into separate files.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20190214152251.2073-6-armbru@redhat.com>
2019-02-18 14:44:04 +01:00
Markus Armbruster 83a22d89b0 qapi: Fix up documentation for recent commit a95291007b
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20190214152251.2073-3-armbru@redhat.com>
2019-02-18 14:44:04 +01:00
Markus Armbruster ce32bf8586 qapi: Belatedly document modular code generation
We generate code for built-ins and sub-modules into separate files
since commit cdb6610ae4 and 252dc3105f (v2.12.0).  Both commits
neglected to update documentation.  Do that now.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20190214152251.2073-2-armbru@redhat.com>
2019-02-18 14:44:04 +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
Markus Armbruster 900cbbde3f qapi: Belatedly update docs for commit 9c2f56e9f9
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20181218182234.28876-2-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2019-01-24 10:01:04 +01:00
Marc-André Lureau 3e270dcacc qapi: add 'if' to alternate members
Add 'if' key to alternate members:

{ 'alternate': 'TestIfAlternate', 'data':
  { 'alt': { 'type': 'TestStruct', 'if': 'COND' } } }

Generated code is not changed by this patch but with "qapi: add #if
conditions to generated code".

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20181213123724.4866-17-marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-12-13 19:20:11 +01:00
Marc-André Lureau a2724280fb qapi: add 'if' to union members
Add 'if' key to union members:

{ 'union': 'TestIfUnion', 'data':
    'mem': { 'type': 'str', 'if': 'COND'} }

The generated code remains unconditional for now. Later patches
generate the conditionals.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20181213123724.4866-16-marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-12-13 19:20:11 +01:00
Marc-André Lureau ccadd6bcba qapi: Add 'if' to implicit struct members
The generated code is for now *unconditional*.  Later patches generate
the conditionals.

Note that union discriminators may not have 'if' conditionals.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20181213123724.4866-14-marcandre.lureau@redhat.com>
Message-Id: <20181213123724.4866-15-marcandre.lureau@redhat.com>
[Patches squashed, commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-12-13 19:20:11 +01:00
Marc-André Lureau 6cc32b0e14 qapi: add 'if' to enum members
QAPISchemaMember gains .ifcond for enum members: inherited classes,
such as QAPISchemaObjectTypeMember, will thus have an ifcond member
after this (those different types will also use the .ifcond to store
the condition and generate conditional code in the following patches).

The generated code remains unconditional for now. Later patches
generate the conditionals.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20181213123724.4866-10-marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-12-13 19:20:11 +01:00
Eric Blake aee03bf367 docs: Update references to JSON RFC
RFC8259 obsoletes RFC7159. Fix a couple of URLs to point to the
newer version.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20181203175702.128701-1-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-12-13 19:10:06 +01:00
Eric Blake 8c643361ee qapi: Add comments to aid debugging generated introspection
We consciously chose in commit 1a9a507b to hide QAPI type names
from the introspection output on the wire, but added a command
line option -u to unmask the type name when doing a debug build.
The unmask option still remains useful to some other forms of
automated analysis, so it will not be removed; however, when it
is not in use, the generated .c file can be hard to read.  At
the time when we first introduced masking, the generated file
consisted only of a monolithic C string, so there was no clean
way to inject any comments.

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

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

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

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

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180827213943.33524-3-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Rebased, update to qapi-code-gen.txt corrected]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-08-28 18:21:38 +02:00
Markus Armbruster 913b5e28a1 qapi: Update docs for generator changes since commit 9ee86b8526
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180828120736.32323-3-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2018-08-28 18:21:38 +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
Peter Maydell 4fd1cbaf14 Monitor patches for 2018-07-03
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Merge remote-tracking branch 'remotes/armbru/tags/pull-monitor-2018-07-03-v2' into staging

Monitor patches for 2018-07-03

# gpg: Signature made Tue 03 Jul 2018 22:20:13 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-2018-07-03-v2: (32 commits)
  qapi: Polish command flags documentation in qapi-code-gen.txt
  monitor: Improve some comments
  qmp: Clean up capability negotiation after commit 02130314d8
  qobject: Let qobject_from_jsonf() fail instead of abort
  qmp: Switch timestamp_put() to qdict_from_jsonf_nofail()
  qmp: Add some comments around null responses
  qmp: Simplify monitor_qmp_respond()
  qmp: Replace get_qmp_greeting() by qmp_greeting()
  qmp: Replace monitor_json_emitter{,raw}() by qmp_{queue,send}_response()
  qmp: Use QDict * instead of QObject * for response objects
  qmp: De-duplicate error response building
  qobject: New qdict_from_jsonf_nofail()
  monitor: Peel off @mon_global wrapper
  monitor: Rename use_io_thr to use_io_thread
  qmp: Don't let JSON errors jump the queue
  qmp: Don't let malformed in-band commands jump the queue
  tests/qmp-test: Demonstrate QMP errors jumping the queue
  qmp: Simplify code around monitor_qmp_dispatch_one()
  qmp: Always free QMPRequest with qmp_request_free()
  qmp: Revert change to handle_qmp_command tracepoint
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-07-05 11:25:14 +01:00
Markus Armbruster 153d73f320 qapi: Polish command flags documentation in qapi-code-gen.txt
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180703085358.13941-33-armbru@redhat.com>
2018-07-03 23:18:56 +02:00
Markus Armbruster 00ecec151d qmp: Redo how the client requests out-of-band execution
Commit cf869d5317 "qmp: support out-of-band (oob) execution" added a
general mechanism for command-independent arguments just for an
out-of-band flag:

    The "control" key is introduced to store this extra flag.  "control"
    field is used to store arguments that are shared by all the commands,
    rather than command specific arguments.  Let "run-oob" be the first.

However, it failed to reject unknown members of "control".  For
instance, in QMP command

    {"execute": "query-name", "id": 42, "control": {"crap": true}}

"crap" gets silently ignored.

Instead of fixing this, revert the general "control" mechanism
(because YAGNI), and do it the way I initially proposed, with key
"exec-oob".  Simpler code, simpler interface.

An out-of-band command

    {"execute": "migrate-pause", "id": 42, "control": {"run-oob": true}}

becomes

    {"exec-oob": "migrate-pause", "id": 42}

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180703085358.13941-13-armbru@redhat.com>
[Commit message typo fixed]
2018-07-03 23:18:56 +02:00
Marc-André Lureau 967c885108 qapi: add 'if' to top-level expressions
Accept 'if' key in top-level elements, accepted as string or list of
string type. The following patches will modify the test visitor to
check the value is correctly saved, and generate #if/#endif code (as a
single #if/endif line or a series for a list).

Example of 'if' key:
{ 'struct': 'TestIfStruct', 'data': { 'foo': 'int' },
  'if': 'defined(TEST_IF_STRUCT)' }

The generated code is for now *unconditional*. Later patches generate
the conditionals.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180703155648.11933-2-marcandre.lureau@redhat.com>
[Commit message and Documentation improved]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-07-03 18:21:24 +02:00
Markus Armbruster c069821220 qmp: Say "out-of-band" instead of "Out-Of-Band"
Affects documentation and a few error messages.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180703085358.13941-2-armbru@redhat.com>
2018-07-03 11:46:54 +02:00
Peter Xu 4bfa7974d9 docs: mention shared state protect for OOB
Out-Of-Band handlers need to protect shared state if there is any.
Mention it in the document.  Meanwhile, touch up some other places too,
either with better English, or reordering of bullets.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180620073223.31964-6-peterx@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-06-30 17:50:48 +02:00