Commit Graph

91 Commits

Author SHA1 Message Date
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
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 3e7fb5811b qapi: Fix code generation for empty modules
When a sub-module doesn't contain any definitions, we don't generate
code for it, but we do generate the #include.

We generate code only for modules that get visited.
QAPISchema.visit() visits only modules that have definitions.  It can
visit modules multiple times.

Clean this up as follows.  Collect entities in their QAPISchemaModule.
Have QAPISchema.visit() call QAPISchemaModule.visit() for each module.
Have QAPISchemaModule.visit() call .visit_module() for itself, and
QAPISchemaEntity.visit() for each of its entities.  This way, we visit
each module exactly once.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20191120182551.23795-6-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-01-14 11:01:58 +01:00
Peter Krempa 2e2e0df270 tests: qapi: Test 'features' of commands
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: <20191018081454.21369-4-armbru@redhat.com>
2019-10-22 13:54:13 +02:00
Markus Armbruster 758f272b6d tests/qapi-schema: Tidy up test output indentation
Command and event details are indented three spaces, everything else
four.  Messed up in commit 156402e504.  Use four spaces consistently.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Message-Id: <20191018081454.21369-2-armbru@redhat.com>
2019-10-22 13:54:13 +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 f03255362a qapi: Permit alternates with just one branch
A union or alternate without branches makes no sense and doesn't work:
it can't be instantiated.  A union or alternate with just one branch
works, but is degenerate.  We accept the former, but reject the
latter.  Weird.  docs/devel/qapi-code-gen.txt doesn't mention the
difference.  It claims an alternate definition is "is similar to a
simple union type".

Permit degenerate alternates to make them consistent with unions.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190913201349.24332-10-armbru@redhat.com>
2019-09-24 14:07:22 +02:00
Markus Armbruster 675b214bc6 qapi: Permit 'boxed' with empty type
We reject empty types with 'boxed': true.  We don't really need that
to work, but making it work is actually simpler than rejecting it, so
do that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190913201349.24332-9-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 8aa3a33e44 tests/qapi-schema: Test for good feature lists in structs
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20190606153803.5278-3-armbru@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-06-12 18:35:17 +02:00
Markus Armbruster 56a4689582 qapi: Fix array first used in a different module
We generally put implicitly defined types in whatever module triggered
their definition.  This is wrong for array types, as the included test
case demonstrates.  Let's have a closer look at it.

Type 'Status' is defined sub-sub-module.json.  Array type ['Status']
occurs in main module qapi-schema-test.json and in
include/sub-module.json.  The main module's use is first, so the array
type gets put into the main module.

The generated C headers define StatusList in qapi-types.h.  But
include/qapi-types-sub-module.h uses it without including
qapi-types.h.  Oops.

To fix that, put the array type into its element type's module.

Now StatusList gets generated into qapi-types-sub-module.h, which all
its users include.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190301154051.23317-8-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2019-03-05 14:43:11 +01:00
Markus Armbruster 5e12eb987b tests/qapi-schema: Cover forward reference to sub-module
The forward reference from the main module to the sub-module works
fine, except for an issue visible in qapi-schema-test.out: the array
type wrapped around the forward reference ends up in the main module,
not the sub-module.  The next commit will explain why that's bad, and
fix it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190301154051.23317-7-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2019-03-05 14:43:11 +01:00
Markus Armbruster b359f4b203 tests: Rename UserDefNativeListUnion to UserDefListUnion
The lists in UserDefNativeListUnion aren't "native", they're lists of
built-in types.  The next commit will add a list of a user-defined
type.  Drop "Native", and adjust the tests using the type.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190301154051.23317-6-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2019-03-05 14:43:11 +01:00
Markus Armbruster 709395f8f6 qapi: Fix code generation for sub-modules in other directories
The #include directives to pull in sub-modules use file names relative
to the main module.  Works only when all modules are in the same
directory, or the main module's output directory is in the compiler's
include path.  Use relative file names instead.

The dummy variable we generate to avoid empty .o files has an invalid
name for sub-modules in other directories.  Fix that.

Both messed up in commit 252dc3105f "qapi: Generate separate .h, .c
for each module".  Escaped testing because tests/qapi-schema-test.json
doesn't cover sub-modules in other directories, only
tests/qapi-schema/include-relpath.json does, and we generate and
compile C code only for the former, not the latter.  Fold the latter
into the former.  This would have caught the mistakes fixed in this
commit.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190301154051.23317-5-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2019-03-05 14:43:11 +01:00
Markus Armbruster 0f20628b24 tests/qapi-schema: Cover conditional arrays
Commit 967c885108 neglected to cover arrays of conditional types.  Do
that now.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190301154051.23317-3-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2019-03-05 14:43:11 +01:00
Markus Armbruster ca0ac758d6 tests/qapi-schema: Make test-qapi.py print arrays
The next few commits mess with array types, and having the changes
exposed in output of test-qapi.py will be useful.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190301154051.23317-2-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[Rationale added to commit message]
2019-03-05 14:41:01 +01:00
Markus Armbruster dcac64711e qapi: Clean up modular built-in code generation a bit
We neglect to call .visit_module() for the special module we use for
built-ins.  Harmless, but clean it up anyway.  The
tests/qapi-schema/*.out now show the built-in module as 'module None'.

Subclasses of QAPISchemaModularCVisitor need to ._add_module() this
special module to enable code generation for built-ins.  When this
hasn't been done, QAPISchemaModularCVisitor.visit_module() does
nothing for the special module.  That looks like built-ins could
accidentally be generated into the wrong module when a subclass
neglects to call ._add_module().  Can't happen, because built-ins are
all visited before any other module.  But that's non-obvious.  Switch
off code generation explicitly.

Rename QAPISchemaModularCVisitor._begin_module() to
._begin_user_module().

New QAPISchemaModularCVisitor._is_builtin_module(), for clarity.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20190214152251.2073-4-armbru@redhat.com>
2019-02-18 14:44:04 +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
Marc-André Lureau 1e381b6559 tests: print enum type members more like object type members
Commit 93bda4dd46 changed the internal representation of enum type
members from str to QAPISchemaMember, but we still print only a
string.  Has been good enough, as the name is the member's only
attribute of interest, but that's about to change.  To prepare, print
them more like object type members.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20181213123724.4866-4-marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-12-13 19:20:11 +01:00
Marc-André Lureau f8c4fdd6ae tests/qapi: Cover commands with 'if' and union / alternate 'data'
Forgotten in commit 967c885108.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20181208111606.8505-19-marcandre.lureau@redhat.com>
Message-Id: <20181208111606.8505-21-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Squashed, commit message adjusted]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-12-13 19:20:11 +01:00
Marc-André Lureau ae6bf76604 tests: add a qmp success-response test
Verify the usage of this schema feature and the API behaviour.  This
should be the only case where qmp_dispatch() returns NULL.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2018-08-31 09:53:10 +02:00
Marc-André Lureau fbf09a2fa4 qapi: add 'ifcond' to visitor methods
Modify the test visitor to check correct passing of values.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180703155648.11933-5-marcandre.lureau@redhat.com>
[Accidental change to roms/seabios dropped]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-07-03 18:38:53 +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
Anton Nefedov 800877bb16 qapi: allow empty branches in flat unions
It often happens that just a few discriminator values imply extra data in
a flat union. Existing checks did not make possible to leave other values
uncovered. Such cases had to be worked around by either stating a dummy
(empty) type or introducing another (subset) discriminator enumeration.

Both options create redundant entities in qapi files for little profit.

With this patch it is not necessary anymore to add designated union
fields for every possible value of a discriminator enumeration.

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Message-Id: <1529311206-76847-2-git-send-email-anton.nefedov@virtuozzo.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-06-22 16:33:46 +02:00
Igor Mammedov 7b13f2c27a tests: qapi-schema tests for allow-preconfig
use new allow-preconfig parameter in tests and make sure that
the QAPISchema can parse allow-preconfig correctly

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1526058959-41425-1-git-send-email-imammedo@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2018-05-30 13:19:14 -03:00
Peter Xu 1a1b11dc0f tests: add oob-test for qapi-schema
It simply tests the new OOB capability, and make sure the QAPISchema can
parse it correctly.

Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180326063901.27425-7-peterx@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-27 10:17:45 -05:00
Peter Xu 4bebca1e42 tests: let qapi-schema tests detect oob
The allow_oob parameter was passed in but not used in tests.  Now
reflect that in the tests, so we need to touch up other command testers
with that new change.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180326063901.27425-6-peterx@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-27 10:17:45 -05:00
Markus Armbruster cf40a0a5c2 qapi: Record 'include' directives in intermediate representation
The include directive permits modular QAPI schemata, but the generated
code is monolithic all the same.  To permit generating modular code,
the front end needs to pass more information on inclusions to the back
ends.  The commit before last added the necessary information to the
parse tree.  This commit adds it to the intermediate representation
and its QAPISchemaVisitor.  A later commit will use this to to
generate modular code.

New entity QAPISchemaInclude represents inclusions.  Call new visitor
method visit_include() for it, so visitors can see the sub-modules a
module includes.

Note that unlike other entities, QAPISchemaInclude has no name, and is
therefore not added to entity_dict.

New QAPISchemaEntity attribute @module names the entity's source file.
Call new visitor method visit_module() when it changes during a visit,
so visitors can keep track of the module being visited.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20180211093607.27351-18-armbru@redhat.com>
[eblake: avoid accidental deletion of self._predefining]
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-02 13:14:10 -06:00
Markus Armbruster 8a84767cc4 qapi: Generate in source order
The generators' conversion to visitors (merge commit 9e72681d16)
changed the processing order of entities from source order to
alphabetical order.  The next commit needs source order, so change it
back.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20180211093607.27351-17-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-02 13:14:10 -06:00
Markus Armbruster 4d2d5c41a9 qapi: Introduce a first class 'null' type
I expect the 'null' type to be useful mostly for members of alternate
types.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-07-24 13:35:11 +02:00
Marc-André Lureau 01b2ffcedd qapi: merge QInt and QFloat in QNum
We would like to use a same QObject type to represent numbers, whether
they are int, uint, or floats. Getters will allow some compatibility
between the various types if the number fits other representations.

Add a few more tests while at it.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170607163635.17635-7-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[parse_stats_intervals() simplified a bit, comment in
test_visitor_in_int_overflow() tidied up, suppress bogus warnings]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-06-20 14:31:31 +02:00
Marc-André Lureau 7c877c8030 tests: Remove test cases for alternates of 'number' and 'int'
Alternates with both a 'number' and an 'int' branch will become
invalid when the next patch merges of QFloat and QInt into QNum.
More sophisticated alternate code could keep them valid, but since
we have no users outside tests, simply drop the tests.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20170607163635.17635-4-marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-06-19 14:56:29 +02:00
Markus Armbruster c0644771eb qapi: Reject alternates that can't work with keyval_parse()
Alternates are sum types like unions, but use the JSON type on the
wire / QType in QObject instead of an explicit tag.  That's why we
require alternate members to have distinct QTypes.

The recently introduced keyval_parse() (commit d454dbe) can only
produce string scalars.  The qobject_input_visitor_new_keyval() input
visitor mostly hides the difference, so code using a QObject input
visitor doesn't have to care whether its input was parsed from JSON or
KEY=VALUE,...  The difference leaks for alternates, as noted in commit
0ee9ae7: a non-string, non-enum scalar alternate value can't currently
be expressed.

In part, this is just our insufficiently sophisticated implementation.
Consider alternate type 'GuestFileWhence'.  It has an integer member
and a 'QGASeek' member.  The latter is an enumeration with values
'set', 'cur', 'end'.  The meaning of b=set, b=cur, b=end, b=0, b=1 and
so forth is perfectly obvious.  However, our current implementation
falls apart at run time for b=0, b=1, and so forth.  Fixable, but not
today; add a test case and a TODO comment.

Now consider an alternate type with a string and an integer member.
What's the meaning of a=42?  Is it the string "42" or the integer 42?
Whichever meaning you pick makes the other inexpressible.  This isn't
just an implementation problem, it's fundamental.  Our current
implementation will pick string.

So far, we haven't needed such alternates.  To make sure we stop and
think before we add one that cannot sanely work with keyval_parse(),
let's require alternate members to have sufficiently distinct
representation in KEY=VALUE,... syntax:

* A string member clashes with any other scalar member

* An enumeration member clashes with bool members when it has value
  'on' or 'off'.

* An enumeration member clashes with numeric members when it has a
  value that starts with '-', '+', or a decimal digit.  This is a
  rather lazy approximation of the actual number syntax accepted by
  the visitor.

  Note that enumeration values starting with '-' and '+' are rejected
  elsewhere already, but better safe than sorry.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1495471335-23707-5-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 16:04:09 +02:00
Markus Armbruster 8168ca8ea3 tests/qapi-schema: Avoid 'str' in alternate test cases
The next commit is going to make alternate members of type 'str'
conflict with other scalar types.  Would break a few test cases that
don't actually require 'str'.  Flip them from 'str' to 'bool' or
'EnumOne'.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1495471335-23707-4-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 87c16dceca qapi: Back out doc comments added just to please qapi.py
This reverts commit 3313b61's changes to tests/qapi-schema/, except
for tests/qapi-schema/doc-*.

We could keep some of these doc comments to serve as positive test
cases.  However, they don't actually add to what we get from doc
comment use in actual schemas, as we we don't test output matches
expectations, and don't systematically cover doc comment features.
Proper positive test coverage would be nice.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1489582656-31133-4-git-send-email-armbru@redhat.com>
2017-03-16 07:13:01 +01:00
Marc-André Lureau 3313b6124b qapi: add qapi2texi script
As the name suggests, the qapi2texi script converts JSON QAPI
description into a texi file suitable for different target
formats (info/man/txt/pdf/html...).

It parses the following kind of blocks:

Free-form:

  ##
  # = Section
  # == Subsection
  #
  # Some text foo with *emphasis*
  # 1. with a list
  # 2. like that
  #
  # And some code:
  # | $ echo foo
  # | -> do this
  # | <- get that
  #
  ##

Symbol description:

  ##
  # @symbol:
  #
  # Symbol body ditto ergo sum. Foo bar
  # baz ding.
  #
  # @param1: the frob to frobnicate
  # @param2: #optional how hard to frobnicate
  #
  # Returns: the frobnicated frob.
  #          If frob isn't frobnicatable, GenericError.
  #
  # Since: version
  # Notes: notes, comments can have
  #        - itemized list
  #        - like this
  #
  # Example:
  #
  # -> { "execute": "quit" }
  # <- { "return": {} }
  #
  ##

That's roughly following the following EBNF grammar:

api_comment = "##\n" comment "##\n"
comment = freeform_comment | symbol_comment
freeform_comment = { "# " text "\n" | "#\n" }
symbol_comment = "# @" name ":\n" { member | tag_section | freeform_comment }
member = "# @" name ':' [ text ] "\n" freeform_comment
tag_section = "# " ( "Returns:", "Since:", "Note:", "Notes:", "Example:", "Examples:" ) [ text ]  "\n" freeform_comment
text = free text with markup

Note that the grammar is ambiguous: a line "# @foo:\n" can be parsed
both as freeform_comment and as symbol_comment.  The actual parser
recognizes symbol_comment.

See docs/qapi-code-gen.txt for more details.

Deficiencies and limitations:
- the generated QMP documentation includes internal types
- union type support is lacking
- type information is lacking in generated documentation
- doc comment error message positions are imprecise, they point
  to the beginning of the comment.
- a few minor issues, all marked TODO/FIXME in the code

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170113144135.5150-16-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[test-qapi.py tweaked to avoid trailing empty lines in .out]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-01-16 10:10:35 +01:00
Eric Blake c818408e44 qapi: Implement boxed types for commands/events
Turn on the ability to pass command and event arguments in
a single boxed parameter, which must name a non-empty type
(although the type can be a struct with all optional members).
For structs, it makes it possible to pass a single qapi type
instead of a breakout of all struct members (useful if the
arguments are already in a struct or if the number of members
is large); for other complex types, it is now possible to use
a union or alternate as the data for a command or event.

The empty type may be technically feasible if needed down the
road, but it's easier to forbid it now and relax things to allow
it later, than it is to allow it now and have to special case
how the generated 'q_empty' type is handled (see commit 7ce106a9
for reasons why nothing is generated for the empty type).  An
alternate type is never considered empty, but now that a boxed
type can be either an object or an alternate, we have to provide
a trivial QAPISchemaAlternateType.is_empty().  The new call to
arg_type.is_empty() during QAPISchemaCommand.check() requires
that we first check the type in question; but there is no chance
of introducing a cycle since objects do not refer back to commands.

We still have a split in syntax checking between ad-hoc parsing
up front (merely validates that 'boxed' has a sane value) and
during .check() methods (if 'boxed' is set, then 'data' must name
a non-empty user-defined type).

Generated code is unchanged, as long as no client uses the
new feature.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1468468228-27827-10-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Test files renamed to *-boxed-*]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-07-19 13:21:08 +02:00
Eric Blake 48825ca419 qapi: Plumb in 'boxed' to qapi generator lower levels
The next patch will add support for passing a qapi union type
as the 'data' of a command.  But to do that, the user function
for implementing the command, as called by the generated
marshal command, must take the corresponding C struct as a
single boxed pointer, rather than a breakdown into one
parameter per member.  Even without a union, being able to use
a C struct rather than a list of parameters can make it much
easier to handle coding with QAPI.

This patch adds the internal plumbing of a 'boxed' flag
associated with each command and event.  In several cases,
this means adding indentation, with one new dead branch and
the remaining branch being the original code more deeply
nested; this was done so that the new implementation in the
next patch is easier to review without also being mixed with
indentation changes.

For this patch, no behavior or generated output changes, other
than the testsuite outputting the value of the new flag
(always False for now).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1468468228-27827-9-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Identifier box renamed to boxed in two places]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-07-19 13:21:08 +02:00
Eric Blake da9cb19385 qapi: Hide tag_name data member of variants
Clean up the only remaining external use of the tag_name field of
QAPISchemaObjectTypeVariants, by explicitly listing the generated
'type' tag for all variants in the testsuite (you can still tell
simple unions by the -wrapper types).  Then we can mark the
tag_name field as private by adding a leading underscore to prevent
any further use.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1468468228-27827-5-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-07-19 13:21:08 +02:00
Eric Blake ac4338f8eb qapi: Allow anonymous base for flat union
Rather than requiring all flat unions to explicitly create
a separate base struct, we can allow the qapi schema to specify
the common members via an inline dictionary. This is similar to
how commands can specify an inline anonymous type for its 'data'.
We already have several struct types that only exist to serve as
a single flat union's base; the next commit will clean them up.
In particular, this patch's change to the BlockdevOptions example
in qapi-code-gen.txt will actually be done in the real QAPI schema.

Now that anonymous bases are legal, we need to rework the
flat-union-bad-base negative test (as previously written, it
forms what is now valid QAPI; tweak it to now provide coverage
of a new error message path), and add a positive test in
qapi-schema-test to use an anonymous base (making the integer
argument optional, for even more coverage).

Note that this patch only allows anonymous bases for flat unions;
simple unions are already enough syntactic sugar that we do not
want to burden them further.  Meanwhile, while it would be easy
to also allow an anonymous base for structs, that would be quite
redundant, as the members can be put right into the struct
instead.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1458254921-17042-15-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-03-18 10:29:26 +01:00
Eric Blake 7599697c66 qapi: Adjust names of implicit types
The original choice of ':obj-' as the prefix for implicit types
made it obvious that we weren't going to clash with any user-defined
names, which cannot contain ':'.  But now we want to create structs
for implicit types, to get rid of special cases in the generators,
and our use of ':' in implicit names needs a tweak to produce valid
C code.

We could transliterate ':' to '_', except that C99 mandates that
"identifiers that begin with an underscore are always reserved for
use as identifiers with file scope in both the ordinary and tag name
spaces".  So it's time to change our naming convention: we can
instead use the 'q_' prefix that we reserved for ourselves back in
commit 9fb081e0.  Technically, since we aren't planning on exposing
the empty type in generated code, we could keep the name ':empty',
but renaming it to 'q_empty' makes the check for startswith('q_')
cover all implicit types, whether or not code is generated for them.

As long as we don't declare 'empty' or 'obj' ticklish, it shouldn't
clash with c_name() prepending 'q_' to the user's ticklish names.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1458254921-17042-5-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-03-18 10:29:25 +01:00
Eric Blake 972a110162 qapi: Fix command with named empty argument type
The generator special-cased

 { 'command':'foo', 'data': {} }

to avoid emitting a visitor variable, but failed to see that

 { 'struct':'NamedEmptyType, 'data': {} }
 { 'command':'foo', 'data':'NamedEmptyType' }

needs the same treatment.  There, the generator happily generates a
visitor to get no arguments, and a visitor to destroy no arguments;
and the compiler isn't happy with that, as demonstrated by the updated
qapi-schema-test.json:

  tests/test-qmp-marshal.c: In function ‘qmp_marshal_user_def_cmd0’:
  tests/test-qmp-marshal.c:264:14: error: variable ‘v’ set but not used [-Werror=unused-but-set-variable]
       Visitor *v;
                ^

No change to generated code except for the testsuite addition.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1458254921-17042-3-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-03-18 10:29:25 +01:00
Eric Blake 68d078395d qapi: Add tests of complex objects within alternate
Upcoming patches will adjust how we visit an object branch of an
alternate; but we were completely lacking testsuite coverage.
Rectify this, so that the future patches will be able to highlight
the changes and still prove that we avoided regressions.

In particular, the use of a flat union UserDefFlatUnion rather
than a simple struct UserDefA as the branch will give us coverage
of an object with variants.  And visiting an alternate as both
the top level and as a nested member gives confidence in correct
memory allocation handling, especially if the test is run under
valgrind.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1455778109-6278-5-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-19 11:08:57 +01:00
Eric Blake 9d3524b39e qapi-visit: Honor prefix of discriminator enum
When we added support for a user-specified prefix for an enum
type (commit 351d36e), we forgot to teach the qapi-visit code
to honor that prefix in the case of using a prefixed enum as
the discriminator for a flat union.  While there is still some
on-list debate on whether we want to keep prefixes, we should
at least make it work as long as it is still part of the code
base.

Reported-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1455665965-27638-1-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-19 11:08:56 +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