Commit Graph

38 Commits

Author SHA1 Message Date
Markus Armbruster 94a3f0af38 docs/qapi-code-gen.txt: Fix QAPI schema examples
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-04 15:47:16 +02:00
Markus Armbruster 3a864e7c52 qapi: Generated code cleanup
Clean up white-space, brace placement, and superfluous #ifdef
QAPI_TYPES_BUILTIN_CLEANUP_DEF.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-04 15:47:16 +02:00
Markus Armbruster 3f99144cd9 qapi-commands: Drop useless initialization
In generated command handlers, the assignment to retval dominates its
only use.  Therefore, its initialization is useless.  Drop it.

Suggested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-04 15:47:15 +02:00
Markus Armbruster 9b090d42ae qapi: Command returning anonymous type doesn't work, outlaw
Reproducer: with

    { 'command': 'user_def_cmd4', 'returns': { 'a': 'int' } }

added to qapi-schema-test.json, qapi-commands.py dies when it tries to
generate the command handler function

    Traceback (most recent call last):
      File "/work/armbru/qemu/scripts/qapi-commands.py", line 359, in <module>
        ret = generate_command_decl(cmd['command'], arglist, ret_type) + "\n"
      File "/work/armbru/qemu/scripts/qapi-commands.py", line 29, in generate_command_decl
        ret_type=c_type(ret_type), name=c_name(name),
      File "/work/armbru/qemu/scripts/qapi.py", line 927, in c_type
        assert isinstance(value, str) and value != ""
    AssertionError

because the return type doesn't exist.

Simply outlaw this usage, and drop or dumb down test cases accordingly.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-04 15:47:15 +02:00
Markus Armbruster 315932b5ed qapi: Fix to reject union command and event arguments
A command's or event's 'data' must be a struct type, given either as a
dictionary, or as struct type name.

Commit dd883c6 tightened the checking there, but not enough: we still
accept 'union'.  Fix to reject it.

We may want to support union types there, but we'll have to extend
qapi-commands.py and qapi-events.py for it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-04 15:47:15 +02:00
Markus Armbruster 016a335bd8 qapi-event: Clean up how name of enum QAPIEvent is made
Use c_name() instead of ad hoc code.  Doesn't upcase the -p prefix,
which is an improvement in my book.  Unbreaks prefix containing '.',
but other funny characters remain broken.  To be fixed next.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-04 15:47:13 +02:00
Markus Armbruster 4247f83900 qapi: Clarify docs on including the same file multiple times
It's idempotent.

While there, update examples to current code.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-04 15:47:13 +02:00
Markus Armbruster 836c3b01d2 qapi: Drop bogus command from docs
Commit 87a560c4 added it in the wrong place.  Commit 59a2c4ce added it
in the right place, but didn't remove it from the wrong place.  Do
that now.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-06-18 14:12:33 +02:00
Markus Armbruster 16d80f6181 qapi: Turn generators' mandatory option -i into an argument
Mandatory option is silly, and the error handling is missing: the
programs crash when -i isn't supplied.  Make it an argument, and check
it properly.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-05-14 18:41:23 +02:00
Eric Blake 363b4262a1 qapi: Tweak doc references to QMP when QGA is also meant
We have more than one qapi schema in use by more than one protocol.
Add a new term 'Client JSON Protocol' for use throughout the
document, to avoid confusion on whether something refers only to
QMP and not QGA.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-05-05 18:39:02 +02:00
Eric Blake 3b2a8b8532 qapi: Document 'struct' metatype
Referring to "type" as both a meta-type (built-in, enum, union,
alternate, or struct) and a specific type (the name that the
schema uses for declaring structs) is confusing.  Now that the
generator accepts 'struct' as a synonym for 'type', update all
documentation to use saner wording.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-05-05 18:39:01 +02:00
Eric Blake 7b1b98c420 qapi: Document new 'alternate' meta-type
The next patch will quit special-casing "'union':'Foo',
'discriminator':{}" and instead use "'alternate':'Foo'".

Separating docs from implementation makes it easier to focus
on wording without holding up code.  In particular, making
alternate a separate type makes for a nice type hierarchy:

          /-------- meta-type ------\
         /              |            \
    simple types    alternate     complex types
    |         |                   |           |
 built-in   enum             type(struct)   union
 |       \    /                            /    \
numeric  string                         simple  flat

A later patch will then clean up 'type' vs. 'struct'
confusion.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-05-05 18:39:00 +02:00
Eric Blake e790e66651 qapi: Document type-safety considerations
Go into more details about the various types of valid expressions
in a qapi schema, including tweaks to document fixes being done
later in the current patch series.  Also fix some stale and missing
documentation in the QMP specification.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-05-05 18:38:59 +02:00
Eric Blake 6fb5545172 qapi: Add copyright declaration on docs
While our top-level COPYING with its GPLv2+ license applies to
any documentation file that omits explicit instructions, these
days it's better to be a good example of calling out our
intentions.  Correct use of GPL requires the use of a copyright
statement, so I'm adding notice to two QAPI documents, by
attributing these files to the initial authors and major
contributors.  I used:

$ git blame --line-porcelain $file \
  | sed -n 's/^author //p' | sort | uniq -c | sort -rn

to determine authorship of these two files.  qmp-spec.txt blames
entirely to Red Hat (easy, since my contribution falls in that
category); while qapi-code-gen.txt has multiple contributors
representing multiple entities.  But since it was originally
supplied by Michael Roth, the notice I added there copies the
notice he has used in other files.  As there is no intended
change in license from the implicit one previously present from
the top level, I have not bothered to CC other contributors;
if we want to weaken things to something looser (such as LGPL)
so that there is no question that someone re-implementing the
spec is not forced to use GPL, that would be a different commit.

CC: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-05-05 18:38:59 +02:00
Eric Blake 59a2c4ce2b qapi: Update docs given recent event, spacing fixes
Commit 21cd70d added event support but didn't document what the
generated code looks like.  Commit 05dfb26 removed some unwanted
spaces in the generated code, but didn't reflect those changes
into the documentation.  Finally, the docs start with a big
disclaimer about QMP not using QAPI yet, which feels rather stale.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2014-09-26 21:18:20 +04:00
Wenchao Xia d6f9c82c62 qapi script: clean up in scripts
This patch improve docs and uses c_type(argentry, is_param=True)
in script.

Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-06-27 09:27:56 -04:00
Wenchao Xia 21cd70dfc1 qapi script: add event support
qapi-event.py will parse the schema and generate qapi-event.c, then
the API in qapi-event.c can be used to handle events in qemu code.
All API have prefix "qapi_event".

The script mainly includes two parts: generate API for each event
define, generate an enum type for all defined events.

Since in some cases the real emit behavior may change, for example,
qemu-img would not send a event, a callback layer is used to
control the behavior. As a result, the stubs at compile time
can be saved, the binding of block layer code and monitor code
will become looser.

Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-06-23 11:01:25 -04:00
Benoît Canet 24fd848950 qapi: skip redundant includes
The purpose of this change is to help create a json file containing
common definitions; each bit of generated C code must be emitted
only one time.

A second history global to all QAPISchema instances has been added
to detect when a file is included more than one time and skip these
includes.
It does not act as a stack and the changes made to it by the
__init__ function are propagated back to the caller so it's really
a global state.

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-16 10:35:59 -04:00
Markus Armbruster 87a560c455 qapi: Show qapi-commands.py invocation in qapi-code-gen.txt
While there, pare down the shell prompts.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-15 15:16:01 -04:00
Markus Armbruster 297a3646c2 qapi: Replace uncommon use of the error API by the common one
We commonly use the error API like this:

    err = NULL;
    foo(..., &err);
    if (err) {
        goto out;
    }
    bar(..., &err);

Every error source is checked separately.  The second function is only
called when the first one succeeds.  Both functions are free to pass
their argument to error_set().  Because error_set() asserts no error
has been set, this effectively means they must not be called with an
error set.

The qapi-generated code uses the error API differently:

    // *errp was initialized to NULL somewhere up the call chain
    frob(..., errp);
    gnat(..., errp);

Errors accumulate in *errp: first error wins, subsequent errors get
dropped.  To make this work, the second function does nothing when
called with an error set.  Requires non-null errp, or else the second
function can't see the first one fail.

This usage has also bled into visitor tests, and two device model
object property getters rtc_get_date() and balloon_stats_get_all().

With the "accumulate" technique, you need fewer error checks in
callers, and buy that with an error check in every callee.  Can be
nice.

However, mixing the two techniques is confusing.  You can't use the
"accumulate" technique with functions designed for the "check
separately" technique.  You can use the "check separately" technique
with functions designed for the "accumulate" technique, but then
error_set() can't catch you setting an error more than once.

Standardize on the "check separately" technique for now, because it's
overwhelmingly prevalent.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-15 14:00:46 -04:00
Markus Armbruster f9bee751be qapi: Normalize marshalling's visitor initialization and cleanup
Input and output marshalling functions do it differently.  Change them
to work the same: initialize the I/O visitor, use it, clean it up,
initialize the dealloc visitor, use it, clean it up.

This delays dealloc visitor initialization in output marshalling
functions, and input visitor cleanup in input marshalling functions.
No functional change, but the latter will be convenient when I change
the error handling.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-15 14:00:45 -04:00
Markus Armbruster 6e2bb3ec70 qapi: Update qapi-code-gen.txt example to match current code
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-15 14:00:45 -04:00
Eric Blake cc1626556d qapi: Document optional arguments' backwards compatibility
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-09 09:11:32 -04:00
Lluís Vilanova a719a27c82 qapi: Add a primitive to include other files from a QAPI schema file
The primitive uses JSON syntax, and include paths are relative to the file using the directive:

  { 'include': 'path/to/file.json' }

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-08 14:19:58 -04:00
Lluís Vilanova 33aaad529e qapi: Use an explicit input file
Use an explicit input file on the command-line instead of reading from standard
input.

It also outputs the proper file name when there's an error.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-05-08 14:19:58 -04:00
Wenchao Xia 5223070c47 qapi script: do not allow string discriminator
Since enum based discriminators provide better type-safety and
ensure that future qapi additions do not forget to adjust dependent
unions, forbid using string as discriminator from now on.

Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-03-11 09:07:42 -04:00
Wenchao Xia bceae7697f qapi script: support enum type as discriminator in union
By default, any union will automatically generate a enum type as
"[UnionName]Kind" in C code, and it is duplicated when the discriminator
is specified as a pre-defined enum type in schema. After this patch,
the pre-defined enum type will be really used as the switch case
condition in generated C code, if discriminator is an enum field.

Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-03-11 09:07:42 -04:00
Eric Blake 63922c6477 qapi: fix documentation example
The QMP wire format uses "", not '', around strings.

* docs/qapi-code-gen.txt: Fix typo.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-10-26 13:01:58 +04:00
Kevin Wolf 622f557f5a qapi-types/visit.py: Inheritance for structs
This introduces a new 'base' key for struct definitions that refers to
another struct type. On the JSON level, the fields of the base type are
included directly into the same namespace as the fields of the defined
type, like with unions. On the C level, a pointer to a struct of the
base type is included.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2013-10-11 16:50:01 +02:00
Kevin Wolf 69dd62dfd6 qapi: Anonymous unions
The discriminator for anonymous unions is the data type. This allows to
have a union type that allows both of these:

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

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

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

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2013-07-26 21:10:11 +02:00
Kevin Wolf 50f2bdc75c qapi: Flat unions with arbitrary discriminator
Instead of the rather verbose syntax that distinguishes base and
subclass fields...

  { "type": "file",
    "read-only": true,
    "data": {
        "filename": "test"
    } }

...we can now have both in the same namespace, allowing a more direct
mapping of the command line, and moving fields between the common base
and subclasses without breaking the API:

  { "driver": "file",
    "read-only": true,
    "filename": "test" }

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2013-07-26 21:09:37 +02:00
Kevin Wolf 51631493e4 docs: Document QAPI union types
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2013-07-26 20:17:15 +02:00
Paolo Bonzini d195325b05 qapi: fix error propagation
Don't overwrite / leak previously set errors.
Make traversal cope with missing mandatory sub-structs.
Don't try to end a container that could not be started.

v1->v2:
- unchanged

v2->v3:
- instead of examining, assert that we never overwrite errors with
  error_set()
- allow visitors to set a NULL struct pointer successfully, so traversal
  of incomplete objects can continue
- check for a NULL "obj" before accessing "(*obj)->has_XXX" (this is not a
  typo, "obj != NULL" implies "*obj != NULL" here)
- fix start_struct / end_struct balance for unions as well

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-07-23 11:55:17 +01:00
Paolo Bonzini 3a86a0fa76 qapi: untangle next_list
Right now, the semantics of next_list are complicated.  The caller must:

* call start_list

* call next_list for each element *including the first*

* on the first call to next_list, the second argument should point to
NULL and the result is the head of the list.  On subsequent calls,
the second argument should point to the last node (last result of
next_list) and next_list itself tacks the element at the tail of the
list.

This works for both input and output visitor, but having the visitor
write memory when it is only reading the list is ugly.  Plus, relying
on *list to detect the first call is tricky and undocumented.

We can initialize so->entry in next_list instead of start_list, leaving
it NULL in start_list.  This way next_list sees clearly whether it is
on the first call---as a bonus, it discriminates the cases based on
internal state of the visitor rather than external state.  We can
also pull the assignment of the list head from generated code up to
next_list.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-03-27 09:14:19 -03:00
Stefan Weil 4238e26416 Fix some spelling bugs in documentation and comments
These errors were detected by codespell:

remaing -> remaining
soley -> solely
virutal -> virtual
seperate -> separate

libcacard.txt still needs some more patches.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-11-17 12:57:36 +00:00
Stefan Hajnoczi acf8394eae qapi: fix typos in documentation JSON examples
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-11-01 06:23:48 +00:00
Stefan Weil 2542bfd51c Fix spelling in comments and debug messages (recieve -> receive)
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Reviewed-by: Andreas Färber <andreas.faerber@web.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-08-29 11:47:33 +01:00
Michael Roth b84da83195 qapi: add QAPI code generation documentation
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>
2011-07-21 16:48:15 -03:00