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

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>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2016-07-19' into staging

QAPI patches for 2016-07-19

# gpg: Signature made Tue 19 Jul 2016 19:35:27 BST
# gpg: using RSA k

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2016-07-19' into staging

QAPI patches for 2016-07-19

# gpg: Signature made Tue 19 Jul 2016 19:35:27 BST
# gpg: using RSA key 0x3870B400EB918653
# 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-qapi-2016-07-19:
net: Use correct type for bool flag
qapi: Change Netdev into a flat union
block: Simplify drive-mirror
block: Simplify block_set_io_throttle
qapi: Implement boxed types for commands/events
qapi: Plumb in 'boxed' to qapi generator lower levels
qapi-event: Simplify visit of non-implicit data
qapi: Drop useless gen_err_check()
qapi: Add type.is_empty() helper
qapi: Hide tag_name data member of variants
qapi: Special case c_name() for empty type
qapi: Require all branches of flat union enum to be covered
net: use Netdev instead of NetClientOptions in client init
qapi: change QmpInputVisitor to QSLIST
qapi: change QmpOutputVisitor to QSLIST

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

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 stru

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>

show more ...

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 th

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>

show more ...

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 var

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>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2016-03-18' into staging

QAPI patches for 2016-03-18

# gpg: Signature made Fri 18 Mar 2016 09:54:57 GMT using RSA key ID EB918653
# gpg:

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2016-03-18' into staging

QAPI patches for 2016-03-18

# gpg: Signature made Fri 18 Mar 2016 09:54:57 GMT using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/pull-qapi-2016-03-18:
qapi: Use anonymous bases in QMP flat unions
qapi: Allow anonymous base for flat union
qapi: Make BlockdevOptions doc example closer to reality
qapi: Don't special-case simple union wrappers
qapi: Drop unused c_null()
qapi: Inline gen_visit_members() into lone caller
qapi-commands: Inline single-use helpers of gen_marshal()
qapi-commands: Utilize implicit struct visits
qapi-event: Utilize implicit struct visits
qapi-event: Drop qmp_output_get_qobject() null check
qapi: Emit implicit structs in generated C
qapi: Adjust names of implicit types
qapi: Make c_type() more OO-like
qapi: Fix command with named empty argument type
qapi: Assert in places where variants are not handled

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

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

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>

show more ...

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

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>

show more ...

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':'NamedEmptyT

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>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2016-02-19' into staging

QAPI patches for 2016-02-19

# gpg: Signature made Fri 19 Feb 2016 10:10:18 GMT using RSA key ID EB918653
# gpg:

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2016-02-19' into staging

QAPI patches for 2016-02-19

# gpg: Signature made Fri 19 Feb 2016 10:10:18 GMT using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/pull-qapi-2016-02-19:
qapi: Change visit_start_implicit_struct to visit_start_alternate
qapi: Don't box branches of flat unions
qapi: Don't box struct branch of alternate
qapi-visit: Use common idiom in gen_visit_fields_decl()
qapi: Emit structs used as variants in topological order
qapi: Adjust layout of FooList types
qapi-visit: Less indirection in visit_type_Foo_fields()
qapi-visit: Unify struct and union visit
qapi: Visit variants in visit_type_FOO_fields()
qapi-visit: Simplify how we visit common union members
qapi: Add tests of complex objects within alternate
qapi: Forbid 'any' inside an alternate
qapi: Forbid empty unions and useless alternates
qapi: Simplify excess input reporting in input visitors
qapi-visit: Honor prefix of discriminator enum

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

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 th

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>

show more ...

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

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>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2015-12-17' into staging

QAPI patches for 2015-12-17

# gpg: Signature made Thu 17 Dec 2015 07:33:41 GMT using RSA key ID EB918653
# gpg:

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2015-12-17' into staging

QAPI patches for 2015-12-17

# gpg: Signature made Thu 17 Dec 2015 07:33:41 GMT using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/pull-qapi-2015-12-17: (40 commits)
qapi: Detect base class loops
qapi: Move duplicate collision checks to schema check()
qapi: Enforce (or whitelist) case conventions on qapi members
qapi: Track enum values by QAPISchemaMember, not string
qapi: Prepare new QAPISchemaMember base class
qapi: Shorter visits of optional fields
qapi: Simplify visits of optional fields
qapi: Fix alternates that accept 'number' but not 'int'
qapi: Inline _make_implicit_tag()
qapi-types: Drop unnedeed ._fwdefn
qapi: Simplify visiting of alternate types
qapi: Convert QType into QAPI built-in enum type
qobject: Rename qtype_code to QType
qobject: Simplify QObject
qapi: Change munging of CamelCase enum values
qapi: Add alias for ErrorClass
cpu: Convert CpuInfo into flat union
qapi: Remove obsolete tests for MAX collision
qapi: Don't let implicit enum MAX member collide
qapi: Tighten the regex on valid names
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

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

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>

show more ...

qapi: Convert QType into QAPI built-in enum type

What's more meta than using qapi to define qapi? :)

Convert QType into a full-fledged[*] builtin qapi enum type, so
that a subsequent patch can then

qapi: Convert QType into QAPI built-in enum type

What's more meta than using qapi to define qapi? :)

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

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

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

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1449033659-25497-4-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

qapi: Fix c_name() munging

The method c_name() is supposed to do two different actions: munge
'-' into '_', and add a 'q_' prefix to ticklish names. But it did
these steps out of order, making it p

qapi: Fix c_name() munging

The method c_name() is supposed to do two different actions: munge
'-' into '_', and add a 'q_' prefix to ticklish names. But it did
these steps out of order, making it possible to submit input that
is not ticklish until after munging, where the output then lacked
the desired prefix.

The failure is exposed easily if you have a compiler that recognizes
C11 keywords, and try to name a member '_Thread-local', as it would
result in trying to compile the declaration 'uint64_t _Thread_local;'
which is not valid. However, this name violates our conventions
(ultimately, want to enforce that no qapi names start with single
underscore), so the test is slightly weaker by instead testing
'wchar-t'; the declaration 'uint64_t wchar_t;' is valid in C (where
wchar_t is only a typedef) but would fail with a C++ compiler (where
it is a keyword).

Fix things by reversing the order of actions within c_name().

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-18-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

qapi: Track simple union tag in object.local_members

We were previously creating all unions with an empty list for
local_members. However, it will make it easier to unify struct
and union generatio

qapi: Track simple union tag in object.local_members

We were previously creating all unions with an empty list for
local_members. However, it will make it easier to unify struct
and union generation if we include the generated tag member in
local_members. That way, we can have a common code pattern:
visit the base (if any), visit the local members (if any), visit
the variants (if any). The local_members of a flat union
remains empty (because the discriminator is already visited as
part of the base). Then, by visiting tag_member.check() during
AlternateType.check(), we no longer need to call it during
Variants.check().

The various front end entities now exist as follows:
struct: optional base, optional local_members, no variants
simple union: no base, one-element local_members, variants with tag_member
from local_members
flat union: base, no local_members, variants with tag_member from base
alternate: no base, no local_members, variants

With the new local members, we require a bit of finesse to
avoid assertions in the clients.

No change to generated code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-2-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2015-11-10' into staging

QAPI patches

# gpg: Signature made Tue 10 Nov 2015 07:12:25 GMT using RSA key ID EB918653
# gpg: Good signature

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2015-11-10' into staging

QAPI patches

# gpg: Signature made Tue 10 Nov 2015 07:12:25 GMT using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/pull-qapi-2015-11-10:
qapi-introspect: Document lack of sorting
qapi: Provide nicer array names in introspection
qapi: More tests of input arrays
qapi: Test failure in middle of array parse
qapi: More tests of alternate output
qapi: Simplify error cleanup in test-qmp-*
qapi: Simplify non-error testing in test-qmp-*
qapi: Plug leaks in test-qmp-*
qapi: Share test_init code in test-qmp-input*
qobject: Protect against use-after-free in qobject_decref()
qapi: Strengthen test of TestStructList
qapi: Use generated TestStruct machinery in tests

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

qapi: Use generated TestStruct machinery in tests

Commit d88f5fd and friends first introduced the various test-qmp-*
tests in 2011, with duplicated hand-rolled TestStruct machinery,
to make sure the

qapi: Use generated TestStruct machinery in tests

Commit d88f5fd and friends first introduced the various test-qmp-*
tests in 2011, with duplicated hand-rolled TestStruct machinery,
to make sure the qapi visitor interface was tested. Later, commit
4f193e3 in 2013 added a .json file for further testing use by the
files, but without consolidating any of the existing hand-rolled
visitors. And with four copies, subtle differences have crept in,
between the tests themselves (mainly whitespace differences, but
also a question of whether to use NULL or "TestStruct" when
calling visit_start_struct()) and from what the generator produces
(the hand-rolled versions did not cater to partially-allocated
objects, because they did not have a deallocation usage).

Of course, just because the visitor interface is tested does not
mean it is a sane interface; and future patches will be changing
some of the visitor contracts. Rather than having to duplicate
the cleanup work in each copy of the TestStruct visitor, and keep
each hand-rolled copy in sync with what the generator supplies, we
might as well just test what the generator should give us in the
first place.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1446791754-23823-2-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2015-11-02' into staging

QAPI patches

# gpg: Signature made Mon 02 Nov 2015 09:07:23 GMT using RSA key ID EB918653
# gpg: Good signature

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2015-11-02' into staging

QAPI patches

# gpg: Signature made Mon 02 Nov 2015 09:07:23 GMT using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/pull-qapi-2015-11-02: (25 commits)
qapi: Simplify gen_struct_field()
qapi: Reserve 'u' member name
qapi: Finish converting to new qapi union layout
tpm: Convert to new qapi union layout
memory: Convert to new qapi union layout
input: Convert to new qapi union layout
char: Convert to new qapi union layout
net: Convert to new qapi union layout
sockets: Convert to new qapi union layout
block: Convert to new qapi union layout
tests: Convert to new qapi union layout
qapi-visit: Convert to new qapi union layout
qapi: Start converting to new qapi union layout
qapi-visit: Remove redundant functions for flat union base
qapi: Unbox base members
qapi: Prefer typesafe upcasts to qapi base classes
qapi-types: Refactor base fields output
qapi-visit: Split off visit_type_FOO_fields forward decl
vnc: Hoist allocation of VncBasicInfo to callers
qapi: Reserve 'q_*' and 'has_*' member names
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

tests/qapi-schema: Test for reserved names, empty struct

Add some testsuite coverage to ensure future patches are on
the right track:

Our current C representation of qapi arrays is done by appendin

tests/qapi-schema: Test for reserved names, empty struct

Add some testsuite coverage to ensure future patches are on
the right track:

Our current C representation of qapi arrays is done by appending
'List' to the element name; but we are not preventing the
creation of an object type with the same name. Add
reserved-type-list.json to test this. Then rename
enum-union-clash.json to reserved-type-kind.json to cover the
reservation that we DO detect, and shorten it to match the fact
that the name is reserved even if there is no clash.

We are failing to detect a collision between a dictionary member
and the implicit 'has_*' flag for another optional member. The
easiest fix would be for a future patch to reserve the entire
"has[-_]" namespace for member names (the collision is also
possible for branch names within flat unions, but only as long as
branch names can collide with (non-variant) members; however,
since future patches are about to remove that, it is not worth
testing here). Add reserved-member-has.json to test this.

A similar collision exists between a dictionary member where
c_name() munges what might otherwise be a reserved name to start
with 'q_', and another member explicitly starts with "q[-_]".
Again, the easiest solution for a future patch will be reserving
the entire namespace, but here for commands as well as members.
Add reserved-member-q.json and reserved-command-q.json to test
this; separate tests since arguably our munging of command 'unix'
to 'qmp_q_unix()' could be done without a q_, which is different
than the munging of a member 'unix' to 'foo.q_unix'.

Finally, our testsuite does not have any compilation coverage
of struct inheritance with empty qapi structs. Update
qapi-schema-test.json to test this.

Note that there is currently no technical reason to forbid type
name patterns from member names, or member name patterns from
types, since the two are not in the same namespace in C and
won't collide; but it's not worth adding positive tests of these
corner cases at this time, especially while there is other churn
pending in patches that rearrange which collisions actually
happen.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-2-git-send-email-eblake@redhat.com>
[Commit message tweaked slightly]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2015-10-15' into staging

QAPI patches

# gpg: Signature made Thu 15 Oct 2015 07:40:46 BST using RSA key ID EB918653
# gpg: Good signature

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2015-10-15' into staging

QAPI patches

# gpg: Signature made Thu 15 Oct 2015 07:40:46 BST using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/pull-qapi-2015-10-15:
qapi: Track location that created an implicit type
qapi: Create simple union type member earlier
qapi: Lazy creation of array types
qapi: Don't use info as witness of implicit object type
qapi: Drop redundant args-member-array test
qapi: Drop redundant flat-union-reverse-define test
qapi: Drop redundant returns-int test
qapi: Move empty-enum to compile-time test
qapi: Drop redundant alternate-good test
qapi: Prepare for errors during check()
qapi: Use predicate callback to determine visit filtering
qapi: Fix regression with '-netdev help'

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

qapi: Lazy creation of array types

Commit ac88219a had several TODO markers about whether we needed
to automatically create the corresponding array type alongside
any other type. It turns out that

qapi: Lazy creation of array types

Commit ac88219a had several TODO markers about whether we needed
to automatically create the corresponding array type alongside
any other type. It turns out that most of the time, we don't!

There are a few exceptions: 1) We have a few situations where we
use an array type in internal code but do not expose that type
through QMP; fix it by declaring a dummy type that forces the
generator to see that we want to use the array type.

2) The builtin arrays (such as intList for QAPI ['int']) must
always be generated, because of the way our QAPI_TYPES_BUILTIN
compile guard works: we have situations (at the very least
tests/test-qmp-output-visitor.c) that include both top-level
"qapi-types.h" (via "error.h") and a secondary
"test-qapi-types.h". If we were to only emit the builtin types
when used locally, then the first .h file would not include all
types, but the second .h does not declare anything at all because
the first .h set QAPI_TYPES_BUILTIN, and we would end up with
compilation error due to things like unknown type 'int8List'.

Actually, we may need to revisit how we do type guards, and
change from a single QAPI_TYPES_BUILTIN over to a different
usage pattern that does one #ifdef per qapi type - right now,
the only types that are declared multiple times between two qapi
.json files for inclusion by a single .c file happen to be the
builtin arrays. But now that we have QAPI 'include' statements,
it is logical to assume that we will soon reach a point where
we want to reuse non-builtin types (yes, I'm thinking about what
it will take to add introspection to QGA, where we will want to
reuse the SchemaInfo type and friends). One #ifdef per type
will help ensure that generating the same qapi type into more
than one qapi-types.h won't cause collisions when both are
included in the same .c file; but we also have to solve how to
avoid creating duplicate qapi-types.c entry points. So that
is a problem left for another day.

Generated code for qapi-types and qapi-visit is drastically
reduced; less than a third of the arrays that were blindly
created were actually needed (a quick grep shows we dropped
from 219 to 69 *List types), and the .o files lost more than
30% of their bulk. [For best results, diff the generated
files with 'git diff --patience --no-index pre post'.]

Interestingly, the introspection output is unchanged - this is
because we already cull all types that are not indirectly
reachable from a command or event, so introspection was already
using only a subset of array types. The subset of types
introspected is now a much larger percentage of the overall set
of array types emitted in qapi-types.h (since the larger set
shrunk), but still not 100% (evidence that the array types
emitted for our new Dummy structs, and the new struct itself,
don't affect QMP).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1444710158-8723-9-git-send-email-eblake@redhat.com>
[Moved array info tracking to a later patch]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

qapi: Drop redundant returns-int test

qapi-schema-test was already testing that we could have a
command returning int, but burned a command name in the whitelist.
Merge the redundant positive test r

qapi: Drop redundant returns-int test

qapi-schema-test was already testing that we could have a
command returning int, but burned a command name in the whitelist.
Merge the redundant positive test returns-int, and pick a name
that reduces the whitelist size.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1444710158-8723-6-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

qapi: Move empty-enum to compile-time test

Rather than just asserting that we can parse an empty enum,
let's also make sure we can compile it, by including it in
qapi-schema-test.

Signed-off-by: Er

qapi: Move empty-enum to compile-time test

Rather than just asserting that we can parse an empty enum,
let's also make sure we can compile it, by including it in
qapi-schema-test.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1444710158-8723-5-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...