Commit Graph

199 Commits

Author SHA1 Message Date
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 c32617a194 qapi2texi: Fix translation of *strong* and _emphasized_
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1490015515-25851-7-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2017-03-21 10:42:58 +01:00
Markus Armbruster 80d1f2e4a5 tests/qapi-schema: Systematic positive doc comment tests
We have a number of negative tests, but we don't have systematic
positive coverage.  Fix that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1490015515-25851-6-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2017-03-21 10:42:55 +01:00
Markus Armbruster 818c331833 tests/qapi-schema: Make test-qapi.py print docs again
test-qapi.py used to print the internal representation of doc comments
(commit 3313b61).  This went away when we dropped the doc comments in
positive tests (commit 87c16dc).  Bring it back, because I'm going to
add real positive doc comment tests.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1490015515-25851-5-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2017-03-21 10:42:52 +01:00
Markus Armbruster 012b126de2 qapi: Fix a misleading parser error message
When choking on a token where an expression is expected, we report
'Expected "{", "[" or string'.  Close, but no cigar.  Fix it to
Expected '"{", "[", string, boolean or "null"'.

Missed in commit e53188a.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1489582656-31133-48-git-send-email-armbru@redhat.com>
2017-03-16 07:13:04 +01:00
Markus Armbruster 816a57cd6e qapi: Fix detection of bogus member documentation
check_definition_doc() checks for member documentation without a
matching member.  It laboriously second-guesses what members
QAPISchema._def_exprs() will create.  That's a stupid game.

Move the check into QAPISchema.check(), where the members are known.
Delegate the actual checking to new QAPIDoc.check().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1489582656-31133-38-git-send-email-armbru@redhat.com>
2017-03-16 07:13:04 +01:00
Markus Armbruster f641d06ad6 tests/qapi-schema: Improve coverage of bogus member docs
New test doc-bad-union-member.json shows we can fail to reject
documentation for nonexistent members.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1489582656-31133-37-git-send-email-armbru@redhat.com>
2017-03-16 07:13:03 +01:00
Markus Armbruster bdc001caaa tests/qapi-schema: Rename doc-bad-args to doc-bad-command-arg
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1489582656-31133-36-git-send-email-armbru@redhat.com>
2017-03-16 07:13:03 +01:00
Markus Armbruster 4ea7148e89 qapi: Move empty doc section checking to doc parser
Results in a more precise error location, but the real reason is
emptying out check_docs() step by step.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1489582656-31133-35-git-send-email-armbru@redhat.com>
2017-03-16 07:13:03 +01:00
Markus Armbruster 2d433236df qapi: Improve error message on @NAME: in free-form doc
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1489582656-31133-34-git-send-email-armbru@redhat.com>
2017-03-16 07:13:03 +01:00
Markus Armbruster 7947016d1c qapi: Move detection of doc / expression name mismatch
Move the check whether the doc matches the expression name from
check_definition_doc() to check_exprs().  This changes the error
location from the comment to the expression.  Makes sense as the
message talks about the expression: "Definition of '%s' follows
documentation for '%s'".  It's also a step towards getting rid of
check_docs().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1489582656-31133-33-git-send-email-armbru@redhat.com>
2017-03-16 07:13:03 +01:00
Markus Armbruster e7823a2adf qapi: Fix detection of doc / expression mismatch
This fixes the errors uncovered by the previous commit.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1489582656-31133-32-git-send-email-armbru@redhat.com>
2017-03-16 07:13:03 +01:00
Markus Armbruster 2028be8eea tests/qapi-schema: Improve doc / expression mismatch coverage
New tests doc-before-include.json and doc-before-pragma.json show we
fail to reject a misplaced expression comment.

New test doc-no-symbol.json shows a bad error message.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1489582656-31133-31-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-16 07:13:03 +01:00
Markus Armbruster 1d8bda128d qapi: The #optional tag is redundant, drop
We traditionally mark optional members #optional in the doc comment.
Before commit 3313b61, this was entirely manual.

Commit 3313b61 added some automation because its qapi2texi.py relied
on #optional to determine whether a member is optional.  This is no
longer the case since the previous commit: the only thing qapi2texi.py
still does with #optional is stripping it out.  We still reject bogus
qapi-schema.json and six places for qga/qapi-schema.json.

Thus, you can't actually rely on #optional to see whether something is
optional.  Yet we still make people add it manually.  That's just
busy-work.

Drop the code to check, fix up and strip out #optional, along with all
instances of #optional.  To keep it out, add code to reject it, to be
dropped again once the dust settles.

No change to generated documentation.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1489582656-31133-18-git-send-email-armbru@redhat.com>
2017-03-16 07:13:02 +01:00
Markus Armbruster 4815374513 qapi: Fix to reject empty union base gracefully
Common Python pitfall: 'assert base_members' fires on [] in addition
to None.  Correct to 'assert base_members is not None'.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1489582656-31133-10-git-send-email-armbru@redhat.com>
2017-03-16 07:13:02 +01:00
Markus Armbruster 707fb2d381 tests/qapi-schema: Cover empty union base
The new test case shows off qapi.py choking on an empty union base.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1489582656-31133-9-git-send-email-armbru@redhat.com>
2017-03-16 07:13:02 +01:00
Markus Armbruster 2cfbae3c42 qapi: Have each QAPI schema declare its name rule violations
qapi.py has a hardcoded white-list of type names that may violate the
rule on use of upper and lower case.  Add a new pragma directive
'name-case-whitelist', and use it to replace the hard-coded
white-list.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1489582656-31133-7-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-16 07:13:02 +01:00
Markus Armbruster 1554a8fae9 qapi: Have each QAPI schema declare its returns white-list
qapi.py has a hardcoded white-list of command names that may violate
the rules on permitted return types.  Add a new pragma directive
'returns-whitelist', and use it to replace the hard-coded white-list.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1489582656-31133-6-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-16 07:13:02 +01:00
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
Markus Armbruster bc52d03ff5 qapi: Make doc comments optional where we don't need them
Since we added the documentation generator in commit 3313b61, doc
comments are mandatory.  That's a very good idea for a schema that
needs to be documented, but has proven to be annoying for testing.

Make doc comments optional again, but add a new directive

    { 'pragma': { 'doc-required': true } }

to let a QAPI schema require them.

Add test cases for the new pragma directive.  While there, plug a
minor hole in includ directive test coverage.

Require documentation in the schemas we actually want documented:
qapi-schema.json and qga/qapi-schema.json.

We could probably make qapi2texi.py cope with incomplete
documentation, but for now, simply make it refuse to run unless the
schema has 'doc-required': true.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1489582656-31133-3-git-send-email-armbru@redhat.com>
[qapi-code-gen.txt wording tweaked]
Reviewed-by: Eric Blake <eblake@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 d0b182392d qapi: Require all branches of flat union enum to be covered
We were previously enforcing that all flat union branches were
found in the corresponding enum, but not that all enum values
were covered by branches.  The resulting generated code would
abort() if the user passes the uncovered enum value.

We don't automatically treat non-present branches in a flat
union as empty types, for symmetry with simple unions (there,
the enum type is generated from the list of all branches, so
there is no way to omit a branch but still have it be part of
the union).

A later patch will add shorthand so that branches that are empty
in flat unions can be declared as 'branch':{} instead of
'branch':'Empty', to avoid the need for an otherwise useless
explicit empty type.  [Such shorthand for simple unions is a bit
harder to justify, since we would still have to generate a
wrapper type that parses 'data':{}, rather than truly being an
empty branch with no additional siblings to the 'type' member.]

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1468468228-27827-3-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 48eb62a74f qapi: Drop useless 'data' member of unions
We started moving away from the use of the 'void *data' member
in the C union corresponding to a QAPI union back in commit
544a373; recent commits have gotten rid of other uses.  Now
that it is completely unused, we can remove the member itself
as well as the FIXME comment.  Update the testsuite to drop the
negative test union-clash-data.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1457021813-10704-11-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-03-05 10:42:06 +01:00
Eric Blake 14f00c6c49 qapi: Rename 'fields' to 'members' in generator
C types and JSON objects don't have fields, but members.  We
shouldn't gratuitously invent terminology.  This patch is a
strict renaming of generator code internals (including testsuite
comments), before later patches rename C interfaces.

No change to generated code with this patch.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1457021813-10704-2-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-03-05 10:40:52 +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 46534309e6 qapi: Forbid 'any' inside an alternate
The whole point of an alternate is to allow some type-safety while
still accepting more than one JSON type.  Meanwhile, the 'any'
type exists to bypass type-safety altogether.  The two are
incompatible: you can't accept every type, and still tell which
branch of the alternate to use for the parse; fix this to give a
sane error instead of a Python stack trace.

Note that other types that can't be alternate members are caught
earlier, by check_type().

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1455778109-6278-4-git-send-email-eblake@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-19 11:08:56 +01:00
Eric Blake 02a57ae32b qapi: Forbid empty unions and useless alternates
Empty unions serve no purpose, and while we compile with gcc
which permits them, strict C99 forbids them.  We happen to inject
a dummy 'void *data' member into the C unions that represent QAPI
unions and alternates, but we want to get rid of that member (it
pollutes the namespace for no good reason), which would leave us
with an empty union if the user didn't provide any branches.  While
empty structs make sense in QAPI, empty unions don't add any
expressiveness to the QMP language.  So prohibit them at parse
time.  Update the documentation and testsuite to match.

Note that the documentation already mentioned that alternates
should have "two or more JSON data types"; so this also fixes
the code to enforce that.  However, we have existing uses of a
union type with only one branch, so the 2-or-more strictness
is intentionally limited to alternates.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1455778109-6278-3-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-19 11:08:56 +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 bac5429ccb qapi: Detect base class loops
It should be fairly obvious that qapi base classes need to
form an acyclic graph, since QMP cannot specify the same
key more than once, while base classes are included as flat
members alongside other members added by the child.  But the
old check_member_clash() parser function was not prepared to
check for this, and entered an infinite recursion (at least
until Python gives up, complaining about nesting too deep).

Now that check_member_clash() has been recently removed,
attempts at self-inheritance trigger an assertion failure
introduced by commit ac88219a.  The obvious fix is to turn
the assertion into a conditional.

This patch includes both the tests (base-cycle-direct and
base-cycle-indirect) and the fix, since the .err file output
for the unfixed case is not useful (particularly when it was
warning about unbounded recursion, as that limit may be
platform-specific).

We don't need to worry about cycles in flat unions (neither
the base type nor the type of a variant can be a union) nor
in alternates (alternate branches cannot themselves be an
alternate).  But if we later allow a union type as a variant,
we will still be okay, as QAPISchemaObjectTypeVariants.check()
triggers the same QAPISchemaObjectType.check() that will
detect any loops.

Likewise, we need not worry about the case of diamond
inheritance where the same class is used for a flat union base
class and one of its variants; either both uses will introduce
a collision in trying to insert the same member name twice, or
the shared type is empty and changes nothing.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1449033659-25497-16-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:29 +01:00
Eric Blake 01cfbaa4c3 qapi: Move duplicate collision checks to schema check()
With the recent commit 'qapi: Detect collisions in C member
names', we have two different locations for detecting clashes -
one at parse time, and another at QAPISchema*.check() time.
Remove all of the ad hoc parser checks, and delete associated
code (for example, the global check_member_clash() method is
no longer needed).

Testing this showed that the test union-bad-branch wasn't adding
much: union-clash-branches also exposes the error message when
branches collide, and we've recently fixed things to avoid an
implicit collision with max.  Likewise, the error for
enum-clash-member changes to report our new detection of
upper case in a value name, unless we modify the test to use
all lower case.

The wording of several error messages has changed, but the
change is generally an improvement rather than a regression.

No change to generated code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1449033659-25497-15-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:29 +01:00
Eric Blake 893e1f2c51 qapi: Enforce (or whitelist) case conventions on qapi members
We document that members of enums and objects should be
'lower-case', although we were not enforcing it.  We have to
whitelist a few pre-existing entities that violate the norms.
Add three new tests to expose the new error message, each of
which first uses the whitelisted name 'UuidInfo' to prove the
whitelist works, then triggers the failure (this is the same
pattern used in the existing returns-whitelist.json test).

Note that by adding this check, we have effectively forbidden
an entity with a case-insensitive clash of member names, for
any entity that is not on the whitelist (although there is
still the possibility to clash via '-' vs. '_').

Not done here: a future patch should also add naming convention
support and whitelist exceptions for command, event, and type
names.

The additions to QAPISchemaMember.check_clash() check whether
info['name'] is in the whitelist (the top-most entity name at
the point 'info' tracks), rather than self.owner (the type,
possibly implicit, that directly owns the member), because it
is easier to maintain the whitelist by the names actually in
the user's .json file, rather than worrying about the names
of implicit types.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1449033659-25497-14-git-send-email-eblake@redhat.com>
[Simplified a bit as per discussion with Eric]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:29 +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
Eric Blake 7264f5c50c 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>
2015-12-17 08:21:28 +01:00
Eric Blake 04e0639d4e qapi: Remove obsolete tests for MAX collision
Now that we no longer collide with an implicit _MAX enum member,
we no longer need to reject it in the ad hoc parser, and can
remove several tests that are no longer needed.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-24-git-send-email-eblake@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:28 +01:00
Eric Blake 59a92feedc qapi: Tighten the regex on valid names
We already documented that qapi names should match specific
patterns (such as starting with a letter unless it was an enum
value or a downstream extension).  Tighten that from a suggestion
into a hard requirement, which frees up names beginning with a
single underscore for qapi internal usage.

The tighter regex doesn't forbid everything insane that a user
could provide (for example, a user could name a type 'Foo-lookup'
to collide with the generated 'Foo_lookup[]' for an enum 'Foo'),
but does a good job at protecting the most obvious uses, and
also happens to reserve single leading underscore for later use.

The handling of enum values starting with a digit is tricky:
commit 9fb081e introduced a subtle bug by using c_name() on
a munged value, which would allow an enum to include the
member 'q-int' in spite of our reservation.  Furthermore,
munging with a leading '_' would fail our tighter regex.  So
fix it by only munging for leading digits (which are never
ticklish in c_name()) and by using a different prefix (I
picked 'D', although any letter should do).

Add new tests, reserved-member-underscore and reserved-enum-q,
to demonstrate the tighter checking.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-22-git-send-email-eblake@redhat.com>
Message-Id: <1447883135-18020-1-git-send-email-eblake@redhat.com>
[Eric's fixup squashed in]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:27 +01:00
Eric Blake c43567c120 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>
2015-12-17 08:21:27 +01:00
Eric Blake 27b60ab93b qapi: Detect collisions in C member names
Detect attempts to declare two object members that would result
in the same C member name, by keying the 'seen' dictionary off
of the C name rather than the qapi name.  It also requires passing
info through the check_clash() methods.

This addresses a TODO and fixes the previously-broken
args-name-clash test.  The resulting error message demonstrates
the utility of the .describe() method added previously.  No change
to generated code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-17-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:27 +01:00
Eric Blake 61a946611b qapi: Remove outdated tests related to QMP/branch collisions
Now that branches are in a separate C namespace, we can remove
the restrictions in the parser that claim a branch name would
collide with QMP, and delete the negative tests that are no
longer problematic.  A separate patch can then add positive
tests to qapi-schema-test to test that any corner cases will
compile correctly.

This reverts the scripts/qapi.py portion of commit 7b2a5c2,
now that the assertions that it plugged are no longer possible.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-15-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:27 +01:00
Eric Blake da34a9bd99 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>
2015-12-17 08:21:26 +01:00
Eric Blake 748053c97b 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>
2015-11-09 16:45:05 +01:00
Eric Blake 5e59baf90a qapi: Reserve 'u' member name
Now that we have separated union tag values from colliding with
non-variant C names, by naming the union 'u', we should reserve
this name for our use.  Note that we want to forbid 'u' even in
a struct with no variants, because it is possible for a future
qemu release to extend QMP in a backwards-compatible manner while
converting from a struct to a flat union.  Fortunately, no
existing clients were using this member name.  If we ever find
the need for QMP to have a member 'u', we could at that time
relax things, perhaps by having c_name() munge the QMP member to
'q_u'.

Note that we cannot forbid 'u' everywhere (by adding the
rejection code to check_name()), because the existing QKeyCode
enum already uses it; therefore we only reserve it as a struct
type member name.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-24-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:28 +01:00
Eric Blake ddf2190896 qapi: Unbox base members
Rather than storing a base class as a pointer to a box, just
store the fields of that base class in the same order, so that
a child struct can be directly cast to its parent.  This gives
less malloc overhead, less pointer dereferencing, and even less
generated code.  Compare to the earlier commit 1e6c1616a "qapi:
Generate a nicer struct for flat unions" (although that patch
had fewer places to change, as less of qemu was directly using
qapi structs for flat unions).  It also allows us to turn on
automatic type-safe wrappers for upcasting to the base class
of a struct.

Changes to the generated code look like this in qapi-types.h:

| struct SpiceChannel {
|-    SpiceBasicInfo *base;
|+    /* Members inherited from SpiceBasicInfo: */
|+    char *host;
|+    char *port;
|+    NetworkAddressFamily family;
|+    /* Own members: */
|     int64_t connection_id;

as well as additional upcast functions like qapi_SpiceChannel_base().
Meanwhile, changes to qapi-visit.c look like:

| static void visit_type_SpiceChannel_fields(Visitor *v, SpiceChannel **obj, Error **errp)
| {
|     Error *err = NULL;
|
|-    visit_type_implicit_SpiceBasicInfo(v, &(*obj)->base, &err);
|+    visit_type_SpiceBasicInfo_fields(v, (SpiceBasicInfo **)obj, &err);
|     if (err) {

(the cast is necessary, since our upcast wrappers only deal with a
single pointer, not pointer-to-pointer); plus the wholesale
elimination of some now-unused visit_type_implicit_FOO() functions.

Without boxing, the corner case of one empty struct having
another empty struct as its base type now requires inserting a
dummy member (previously, the 'Base *base' member sufficed).

And now that we no longer consume a 'base' member in the generated
C struct, we can delete the former negative struct-base-clash-base
test.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-11-git-send-email-eblake@redhat.com>
[Commit message tweaked slightly]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:26 +01:00
Eric Blake 9fb081e0b9 qapi: Reserve 'q_*' and 'has_*' member names
c_name() produces names starting with 'q_' when protecting a
dictionary member name that would fail to directly compile, but
in doing so can cause clashes with any member name already
beginning with 'q-' or 'q_'.  Likewise, we create a C name 'has_'
for any optional member that can clash with any member name
beginning with 'has-' or 'has_'.

Technically, rather than blindly reserving the namespace,
we could try to complain about user names only when an actual
collision occurs, or even teach c_name() how to munge names
to avoid collisions.  But it is not trivial, especially when
collisions can occur across multiple types (such as via
inheritance or flat unions).  Besides, no existing .json
files are trying to use these names.  So it's easier to just
outright forbid the potential for collision.  We can always
relax things in the future if a real need arises for QMP to
express member names that have been forbidden here.

'has_' only has to be reserved for struct/union member names,
while 'q_' is reserved everywhere (matching the fact that
only members can be optional, while we use c_name() for munging
both members and entities).  Note that we could relax 'q_'
restrictions on entities independently from member names; for
example, c_name('qmp_' + 'unix') would result in a different
function name than our current 'qmp_' + c_name('unix').

Update and add tests to cover the new error messages.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-6-git-send-email-eblake@redhat.com>
[Consistently pass protect=False to c_name(); commit message tweaked
slightly]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:26 +01:00
Eric Blake 255960dd37 qapi: Reserve '*List' type names for list types
Type names ending in 'List' can clash with qapi list types in
generated C.  We don't currently use such names. It is easier to
outlaw them now than to worry about how to resolve such a clash
in the future. For precedence, see commit 4dc2e69, which did the
same for names ending in 'Kind' versus implicit enum types for
qapi unions.

Update the testsuite to match.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-5-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:26 +01:00
Eric Blake 1976708321 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>
2015-11-02 08:30:25 +01:00
Eric Blake 9f08c8ec73 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>
2015-10-15 08:39:08 +02:00
Eric Blake 849ab13c16 qapi: Drop redundant args-member-array test
qapi-schema-test already ensures that we can correctly compile
an array of enums (__org.qemu_x-command), an array of builtins
(UserDefNativeListUnion), and an array of structs (again
__org.qemu_x-command).  That means args-member-array is not
adding any additional parse-only test coverage, so drop it.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1444760807-11307-1-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-15 08:39:08 +02:00
Eric Blake 70478cef83 qapi: Drop redundant flat-union-reverse-define test
As of commit 8c3f8e77, we test compilation of forward references
for a struct base type (UserDefOne), flat union base type
(UserDefUnionBase), and flat union branch type
(UserDefFlatUnion2). The only remaining forward reference being
tested for parsing in flat-union-reverse-define was a forward
enum declaration.  Once we make sure that always compiles,
the smaller parse-only test is redundant and can be deleted.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1444710158-8723-7-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-15 08:39:07 +02:00
Eric Blake cae95eae62 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>
2015-10-15 08:39:07 +02:00
Eric Blake 625b251c69 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>
2015-10-15 08:39:07 +02:00
Eric Blake baabb84c5b qapi: Drop redundant alternate-good test
The alternate-good.json test was already covered by
qapi-schema-test.json.  As future commits will be tweaking
how alternates are laid out, removing the duplicate test now
reduces churn.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1444710158-8723-4-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-15 08:39:07 +02:00
Eric Blake 376863ef48 qapi: Reuse code for flat union base validation
Rather than open-code the check for a valid base type, we
should reuse the common functionality. This allows for
consistent error messages, and also makes it easier for a
later patch to turn on support for inline anonymous base
structures.

Test flat-union-inline is updated to test only one feature
(anonymous branch dictionaries), which can be implemented
independently (test flat-union-bad-base already covers the
idea of an anonymous base dictionary).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1443565276-4535-10-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12 18:46:49 +02:00
Eric Blake 9c51b44129 qapi: Test use of 'number' within alternates
Add some testsuite exposure for use of a 'number' as part of
an alternate.  The current state of the tree has a few bugs
exposed by this: our input parser depends on the ordering of
how the qapi schema declared the alternate, and the parser
does not accept integers for a 'number' in an alternate even
though it does for numbers outside of an alternate.

Mixing 'int' and 'number' in the same alternate is unusual,
since both are supplied by json-numbers, but there does not
seem to be a technical reason to forbid it given that our
json lexer distinguishes between json-numbers that can be
represented as an int vs. those that cannot.

Improve the existing test_visitor_in_alternate() to match the
style of the new test_visitor_in_alternate_number(), and to
ensure full coverage of all possible qtype parsing.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1443565276-4535-9-git-send-email-eblake@redhat.com>
[Eric's follow-up fixes squashed in]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12 18:46:13 +02:00
Eric Blake 8d25dd101f qapi: Add tests for empty unions
The documentation claims that alternates are useful for
allowing two or more types, although nothing enforces this.
Meanwhile, it is silent on whether empty unions are allowed.
In practice, the generated code will compile, in part because
we have a 'void *data' branch; but attempting to visit such a
type will cause an abort().  While there's no technical reason
that a degenerate union could not be made to work, it's harder
to justify the time spent in chasing known (the current
abort() during visit) and unknown corner cases, than it would
be to just outlaw them.  A future patch will probably take the
approach of forbidding them; in the meantime, we can at least
add testsuite coverage to make it obvious where things stand.

In addition to adding tests to expose the problems, we also
need to adjust existing tests that are meant to test something
else, but which could fail for the wrong reason if we reject
degenerate alternates/unions.

Note that empty structs are explicitly supported (for example,
right now they are the only way to specify that one branch of a
flat union adds no additional members), and empty enums are
covered by the testsuite as working (even if they do not seem
to have much use).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1443565276-4535-8-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12 18:44:54 +02:00
Eric Blake 7b2a5c2f9a qapi: Avoid assertion failure on union 'type' collision
The previous commit added two tests that triggered an assertion
failure. It's fairly straightforward to avoid the failure by
just outright forbidding the collision between a union's tag
values and its discriminator name (including the implicit name
'kind' supplied for simple unions [*]).  Ultimately, we'd like
to move the collision detection into QAPISchema*.check(), but
for now it is easier just to enhance the existing checks.

[*] Of course, down the road, we have plans to rename the simple
union tag name to 'type' to match the QMP wire name, but the
idea of the collision will still be present even then.

Technically, we could avoid the collision by naming the C union
members representing each enum value as '_case_value' rather
than 'value'; but until we have an actual qapi client (and not
just our testsuite) that has a legitimate reason to match a
case label to the name of a QMP key and needs the name munging
to satisfy the compiler, it's easier to just reject the qapi
as invalid.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1443565276-4535-7-git-send-email-eblake@redhat.com>
[Polished a few comments]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12 18:44:54 +02:00
Eric Blake d220fbcd1d qapi: Test for various name collisions
Expose some weaknesses in the generator: we don't always forbid
the generation of structs that contain multiple members that map
to the same C or QMP name.  This has already been marked FIXME in
qapi.py in commit d90675f, but having more tests will make sure
future patches produce desired behavior; and updating existing
patches to better document things doesn't hurt, either.  Some of
these collisions are already caught in the old-style parser
checks, but ultimately we want all collisions to be caught in the
new-style QAPISchema*.check() methods.

This patch focuses on C struct members, and does not consider
collisions between commands and events (affecting C function
names), or even collisions between generated C type names with
user type names (for things like automatic FOOList struct
representing array types or FOOKind for an implicit enum).

There are two types of struct collisions we want to catch:
 1) Collision between two keys in a JSON object. qapi.py prevents
    that within a single struct (see test duplicate-key), but it is
    possible to have collisions between a type's members and its
    base type's members (existing tests struct-base-clash,
    struct-base-clash-deep), and its flat union variant members
    (renamed test flat-union-clash-member).
 2) Collision between two members of the C struct that is generated
    for a given QAPI type:
    a) Multiple QAPI names map to the same C name (new test
       args-name-clash)
    b) A QAPI name maps to a C name that is used for another purpose
       (new tests flat-union-clash-branch, struct-base-clash-base,
       union-clash-data). We already fixed some such cases in commit
       0f61af3e and 1e6c1616, but more remain.
    c) Two C names generated for other purposes clash
       (updated test alternate-clash, new test union-clash-branches,
       union-clash-type, flat-union-clash-type)

Ultimately, if we need to have a flat union where a tag value
clashes with a base member name, we could change the generator to
name the union (using 'foo.u.value' rather than 'foo.value') or
otherwise munge the C name corresponding to tag values.  But
unless such a need arises, it will probably be easier to just
forbid these collisions.

Some of these negative tests will be deleted later, and positive
tests added to qapi-schema-test.json in their place, when the
generator code is reworked to avoid particular code generation
collisions in class 2).

[Note that viewing this patch with git rename detection enabled
may see some confusion due to renaming some tests while adding
others, but where the content is similar enough that git picks
the wrong pre- and post-patch files to associate]

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1443565276-4535-6-git-send-email-eblake@redhat.com>
[Improve commit message and comments a bit, drop an unrelated test]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12 18:44:54 +02:00
Eric Blake 7408fb67c0 qapi: Improve 'include' error message
Use of '"...%s" % include' to print non-strings can lead to
ugly messages, such as this (if the .json change is applied
without the qapi.py change):
 Expected a file name (string), got: OrderedDict()

Better is to just omit the actual non-string value in the
message.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1443565276-4535-3-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12 18:44:54 +02:00
Markus Armbruster 39a1815816 qapi: New QMP command query-qmp-schema for QMP introspection
qapi/introspect.json defines the introspection schema.  It's designed
for QMP introspection, but should do for similar uses, such as QGA.

The introspection schema does not reflect all the rules and
restrictions that apply to QAPI schemata.  A valid QAPI schema has an
introspection value conforming to the introspection schema, but the
converse is not true.

Introspection lowers away a number of schema details, and makes
implicit things explicit:

* The built-in types are declared with their JSON type.

  All integer types are mapped to 'int', because how many bits we use
  internally is an implementation detail.  It could be pressed into
  external interface service as very approximate range information,
  but that's a bad idea.  If we need range information, we better do
  it properly.

* Implicit type definitions are made explicit, and given
  auto-generated names:

  - Array types, named by appending "List" to the name of their
    element type, like in generated C.

  - The enumeration types implicitly defined by simple union types,
    named by appending "Kind" to the name of their simple union type,
    like in generated C.

  - Types that don't occur in generated C.  Their names start with ':'
    so they don't clash with the user's names.

* All type references are by name.

* The struct and union types are generalized into an object type.

* Base types are flattened.

* Commands take a single argument and return a single result.

  Dictionary argument or list result is an implicit type definition.

  The empty object type is used when a command takes no arguments or
  produces no results.

  The argument is always of object type, but the introspection schema
  doesn't reflect that.

  The 'gen': false directive is omitted as implementation detail.

  The 'success-response' directive is omitted as well for now, even
  though it's not an implementation detail, because it's not used by
  QMP.

* Events carry a single data value.

  Implicit type definition and empty object type use, just like for
  commands.

  The value is of object type, but the introspection schema doesn't
  reflect that.

* Types not used by commands or events are omitted.

  Indirect use counts as use.

* Optional members have a default, which can only be null right now

  Instead of a mandatory "optional" flag, we have an optional default.
  No default means mandatory, default null means optional without
  default value.  Non-null is available for optional with default
  (possible future extension).

* Clients should *not* look up types by name, because type names are
  not ABI.  Look up the command or event you're interested in, then
  follow the references.

  TODO Should we hide the type names to eliminate the temptation?

New generator scripts/qapi-introspect.py computes an introspection
value for its input, and generates a C variable holding it.

It can generate awfully long lines.  Marked TODO.

A new test-qmp-input-visitor test case feeds its result for both
tests/qapi-schema/qapi-schema-test.json and qapi-schema.json to a
QmpInputVisitor to verify it actually conforms to the schema.

New QMP command query-qmp-schema takes its return value from that
variable.  Its reply is some 85KiBytes for me right now.

If this turns out to be too much, we have a couple of options:

* We can use shorter names in the JSON.  Not the QMP style.

* Optionally return the sub-schema for commands and events given as
  arguments.

  Right now qmp_query_schema() sends the string literal computed by
  qmp-introspect.py.  To compute sub-schema at run time, we'd have to
  duplicate parts of qapi-introspect.py in C.  Unattractive.

* Let clients cache the output of query-qmp-schema.

  It changes only on QEMU upgrades, i.e. rarely.  Provide a command
  query-qmp-schema-hash.  Clients can have a cache indexed by hash,
  and re-query the schema only when they don't have it cached.  Even
  simpler: put the hash in the QMP greeting.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-21 09:56:49 +02:00
Markus Armbruster 2d21291ae6 qapi: Pseudo-type '**' is now unused, drop it
'gen': false needs to stay for now, because netdev_add is still using
it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1442401589-24189-25-git-send-email-armbru@redhat.com>
2015-09-21 09:56:49 +02:00
Markus Armbruster 28770e057f qapi: Introduce a first class 'any' type
It's first class, because unlike '**', it actually works, i.e. doesn't
require 'gen': false.

'**' will go away next.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
2015-09-21 09:56:49 +02:00
Markus Armbruster 05f43a9608 qapi-event: Convert to QAPISchemaVisitor, fixing data with base
Fixes events whose data is struct with base to include the struct's
base members.  Test case is qapi-schema-test.json's event
__org.qemu_x-command:

    { 'event': '__ORG.QEMU_X-EVENT', 'data': '__org.qemu_x-Struct' }

    { 'struct': '__org.qemu_x-Struct', 'base': '__org.qemu_x-Base',
      'data': { '__org.qemu_x-member2': 'str' } }

    { 'struct': '__org.qemu_x-Base',
      'data': { '__org.qemu_x-member1': '__org.qemu_x-Enum' } }

Patch's effect on generated qapi_event_send___org_qemu_x_event():

    -void qapi_event_send___org_qemu_x_event(const char *__org_qemu_x_member2,
    +void qapi_event_send___org_qemu_x_event(__org_qemu_x_Enum __org_qemu_x_member1,
    +                                        const char *__org_qemu_x_member2,
                                             Error **errp)
     {
         QDict *qmp;
    @@ -224,6 +225,10 @@ void qapi_event_send___org_qemu_x_event(
             goto clean;
         }

    +    visit_type___org_qemu_x_Enum(v, &__org_qemu_x_member1, "__org.qemu_x-member1", &local_err);
    +    if (local_err) {
    +        goto clean;
    +    }
         visit_type_str(v, (char **)&__org_qemu_x_member2, "__org.qemu_x-member2", &local_err);
         if (local_err) {
             goto clean;

Code is generated in a different order now, but that doesn't matter.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
2015-09-21 09:56:48 +02:00
Markus Armbruster 441cbac0c7 qapi-visit: Convert to QAPISchemaVisitor, fixing bugs
Fixes flat unions to visit the base's base members (the previous
commit merely added them to the struct).  Same test case.

Patch's effect on visit_type_UserDefFlatUnion():

     static void visit_type_UserDefFlatUnion_fields(Visitor *m, UserDefFlatUnion **obj, Error **errp)
     {
         Error *err = NULL;

    +    visit_type_int(m, &(*obj)->integer, "integer", &err);
    +    if (err) {
    +        goto out;
    +    }
         visit_type_str(m, &(*obj)->string, "string", &err);
         if (err) {
             goto out;

Test cases updated for the bug fix.

Fixes alternates to generate a visitor for their implicit enumeration
type.  None of them are currently used, obviously.  Example:
block-core.json's BlockdevRef now generates
visit_type_BlockdevRefKind().

Code is generated in a different order now, and therefore has got a
few new forward declarations.  Doesn't matter.

The guard QAPI_VISIT_BUILTIN_VISITOR_DECL is renamed to
QAPI_VISIT_BUILTIN.

The previous commit's two ugly special cases exist here, too.  Mark
both TODO.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-21 09:56:40 +02:00
Markus Armbruster 2b162ccbe8 qapi-types: Convert to QAPISchemaVisitor, fixing flat unions
Fixes flat unions to get the base's base members.  Test case is from
commit 2fc0043, in qapi-schema-test.json:

    { 'union': 'UserDefFlatUnion',
      'base': 'UserDefUnionBase',
      'discriminator': 'enum1',
      'data': { 'value1' : 'UserDefA',
                'value2' : 'UserDefB',
                'value3' : 'UserDefB' } }

    { 'struct': 'UserDefUnionBase',
      'base': 'UserDefZero',
      'data': { 'string': 'str', 'enum1': 'EnumOne' } }

    { 'struct': 'UserDefZero',
      'data': { 'integer': 'int' } }

Patch's effect on UserDefFlatUnion:

     struct UserDefFlatUnion {
         /* Members inherited from UserDefUnionBase: */
    +    int64_t integer;
         char *string;
         EnumOne enum1;
         /* Own members: */
         union { /* union tag is @enum1 */
             void *data;
             UserDefA *value1;
             UserDefB *value2;
             UserDefB *value3;
         };
     };

Flat union visitors remain broken.  They'll be fixed next.

Code is generated in a different order now, but that doesn't matter.

The two guards QAPI_TYPES_BUILTIN_STRUCT_DECL and
QAPI_TYPES_BUILTIN_CLEANUP_DECL are replaced by just
QAPI_TYPES_BUILTIN.

Two ugly special cases for simple unions now stand out like sore
thumbs:

1. The type tag is named 'type' everywhere, except in generated C,
   where it's 'kind'.

2. QAPISchema lowers simple unions to semantically equivalent flat
   unions.  However, the C generated for a simple unions differs from
   the C generated for its equivalent flat union, and we therefore
   need special code to preserve that pointless difference for now.

Mark both TODO.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-21 09:53:16 +02:00
Markus Armbruster 156402e504 tests/qapi-schema: Convert test harness to QAPISchemaVisitor
The old code prints the result of parsing (list of expression
dictionaries), and partial results of semantic analysis (list of enum
dictionaries, list of struct dictionaries).

The new code prints a trace of a schema visit, i.e. what the back-ends
are going to use.  Built-in and array types are omitted, because
they're boring.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-21 09:32:50 +02:00
Markus Armbruster ac88219a6c qapi: New QAPISchema intermediate reperesentation
The QAPI code generators work with a syntax tree (nested dictionaries)
plus a few symbol tables (also dictionaries) on the side.

They have clearly outgrown these simple data structures.  There's lots
of rummaging around in dictionaries, and information is recomputed on
the fly.  For the work I'm going to do, I want more clearly defined
and more convenient interfaces.

Going forward, I also want less coupling between the back-ends and the
syntax tree, to make messing with the syntax easier.

Create a bunch of classes to represent QAPI schemata.

Have the QAPISchema initializer call the parser, then walk the syntax
tree to create the new internal representation, and finally perform
semantic analysis.

Shortcut: the semantic analysis still relies on existing check_exprs()
to do the actual semantic checking.  All this code needs to move into
the classes.  Mark as TODO.

Simple unions are lowered to flat unions.  Flat unions and structs are
represented as a more general object type.

Catching name collisions in generated code would be nice.  Mark as
TODO.

We generate array types eagerly, even though most of them aren't used.
Mark as TODO.

Nothing uses the new intermediate representation just yet, thus no
change to generated files.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-21 09:31:29 +02:00
Daniel P. Berrange 351d36e454 qapi: allow override of default enum prefix naming
The camel_to_upper() method applies some heuristics to turn
a mixed case type name into an all-uppercase name. This is
used for example, to generate enum constant name prefixes.

The heuristics don't also generate a satisfactory name
though. eg

  { 'enum': 'QCryptoTLSCredsEndpoint',
    'data': ['client', 'server']}

Results in Q_CRYPTOTLS_CREDS_ENDPOINT_CLIENT. This has
an undesirable _ after the initial Q and is missing an
_ between the CRYPTO & TLS strings.

Rather than try to add more and more heuristics to try
to cope with this, simply allow the QAPI schema to
specify the desired enum constant prefix explicitly.

eg

  { 'enum': 'QCryptoTLSCredsEndpoint',
    'prefix': 'QCRYPTO_TLS_CREDS_ENDPOINT',
    'data': ['client', 'server']}

Now gives the QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT name.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-09-15 10:59:28 +01:00
Markus Armbruster eddf817bd8 qapi: Simplify error reporting for array types
check_type() first checks and peels off the array type, then checks
the element type.  For two out of four error messages, it takes pains
to report errors for "array of T" instead of just T.  Odd.  Let's
examine the errors.

* Unknown element type, e.g.
  tests/qapi-schema/args-array-unknown.json:

      Member 'array' of 'data' for command 'oops' uses unknown type
      'array of NoSuchType'

  To make sense of this, you need to know that 'array of NoSuchType'
  refers to '[NoSuchType]'.  Easy enough.  However, simply reporting

      Member 'array' of 'data' for command 'oops' uses unknown type
      'NoSuchType'

  is at least as easy to understand.

* Element type's meta-type is inadmissible, e.g.
  tests/qapi-schema/returns-whitelist.json:

      'returns' for command 'no-way-this-will-get-whitelisted' cannot
      use built-in type 'array of int'

  'array of int' is technically not a built-in type, but that's
  pedantry.  However, simply reporting

      'returns' for command 'no-way-this-will-get-whitelisted' cannot
      use built-in type 'int'

  avoids the issue, and is at least as easy to understand.

* The remaining two errors are unreachable, because the array checking
  ensures that value is a string.

Thus, reporting some errors for "array of T" instead of just T works,
but doesn't really improve things.  Drop it.

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 c6b71e5ae7 qapi: Fix errors for non-string, non-dictionary members
Fixes the errors demonstrated by the previous commit.

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 10689e36eb tests/qapi-schema: Cover non-string, non-dictionary members
We always report "should be a dictionary" then.  This is misleading:
when allow_dict, it can be a dictionary or a type name string, else it
can only be a type name.

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 91f9816da4 tests/qapi-schema: Cover two more syntax errors
Syntax error coverage should now be complete.

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 65fbe12545 qapi: Drop one of two "simple union must not have base" checks
The first check ensures the second one can't trigger.  Drop the first
one, because the second one is in a more logical place, and emits a
nicer error message.

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 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 d9658d58e3 qapi-tests: New tests for union, alternate command arguments
A command's 'data' must be a struct type, given either as a
dictionary, or as struct type name.

Existing test case data-int.json covers simple type 'int'.  Add test
cases for type names referring to union and alternate types.

The latter is caught (good), but the former is not (bug).

Events have the same problem, but since they get checked by the same
code, we don't bother to duplicate the tests.

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 6af9a8fc8e tests/qapi-schema: Rename tests from data- to args-
Since every schema entity has 'data', the data- prefix conveys no
information.  These tests actually exercise commands.  Only commands
have arguments, so change the prefix to to args-.

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 80e60a19a8 tests/qapi-schema: Restore test case for flat union base bug
Test case added in commit 2fc0043, and messed up in commit 5223070.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-04 15:47:14 +02:00
Markus Armbruster 999387782f tests/qapi-schema: Document events with base don't work
When event FOO's 'data' is a struct with a base, we consider only the
struct's direct members, and ignore its base.  The generated
qapi_event_send_foo() doesn't take arguments for base members.

No such events currently exist in the QMP schema.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-04 15:47:14 +02:00
Markus Armbruster 422e16aac4 tests/qapi-schema: Document alternate's enum lacks visit function
We generate a declaration, but no definition.

The QMP schema has two: Qcow2OverlapChecks and BlockdevRef.  Neither
visit_type_Qcow2OverlapChecksKind() nor visit_type_BlockdevRefKind()
is actually used.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-04 15:47:14 +02:00
Markus Armbruster 8c3f8e7721 qapi-visit: Fix generated code when schema has forward refs
The visit_type_implicit_FOO() are generated on demand, right before
their first use.  Used by visit_type_STRUCT_fields() when STRUCT has
base FOO, and by visit_type_UNION() when flat UNION has member a FOO.

If the schema defines FOO after its first use as struct base or flat
union member, visit_type_implicit_FOO() calls
visit_type_implicit_FOO() before its definition, which doesn't
compile.

Rearrange qapi-schema-test.json to demonstrate the bug.

Fix by generating the necessary forward declaration.

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 f9a1427361 qapi: Catch and reject flat union branch of array type
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-06-18 14:19:47 +02:00
Markus Armbruster 75276710ae tests/qapi-schema: New flat union array branch test case
The new test demonstrates another generator crash.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-06-18 14:19:47 +02:00
Markus Armbruster 8608d25251 qapi: Fix file name in error messages for included files
We print the name as it appears in the include expression.  Tools
processing error messages want it relative to the working directory.
Make it so.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-06-18 14:12:34 +02:00
Eric Blake e3c4c3d796 qapi: Support downstream events and commands
Enhance the testsuite to cover downstream events and commands.
Events worked without more tweaks, but commands needed a few final
updates in the generator to mangle names in the appropriate places.
In making those tweaks, it was easier to drop type_visitor() and
inline its actions instead.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-05-14 18:21:27 +02:00
Eric Blake d1f07c86c0 qapi: Support downstream alternates
Enhance the testsuite to cover downstream alternates, including
whether the branch name or type is downstream.  Update the
generator to mangle alternate names in the appropriate places.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-05-14 18:21:24 +02:00
Eric Blake 857af5f06c qapi: Support downstream flat unions
Enhance the testsuite to cover downstream flat unions, including
the base type, discriminator name and type, and branch name and
type.  Update the generator to mangle the union names in the
appropriate places.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-05-14 18:21:21 +02:00
Eric Blake bb33729043 qapi: Support downstream simple unions
Enhance the testsuite to cover downstream simple unions, including
when a union branch is a downstream name.  Update the generator to
mangle the union names in the appropriate places.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-05-14 18:21:17 +02:00
Eric Blake 83a02706bb qapi: Support downstream structs
Enhance the testsuite to cover downstream structs, including struct
members and base structs.  Update the generator to mangle the
struct names in the appropriate places.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-05-14 18:21:13 +02:00
Eric Blake fce384b8e5 qapi: Support downstream enums
Enhance the testsuite to cover a downstream enum type and enum
string.  Update the generator to mangle the enum name in the
appropriate places.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-05-14 18:21:09 +02:00
Eric Blake ff55d72eaf qapi: Check for member name conflicts with a base class
Our type inheritance for both 'struct' and for flat 'union' merges
key/value pairs from the base class with those from the type in
question.  Although the C code currently boxes things so that there
is a distinction between which member is referred to, the QMP wire
format does not allow passing a key more than once in a single
object.  Besides, if we ever change the generated C code to not be
quite so boxy, we'd want to avoid duplicate member names there,
too.

Fix a testsuite entry added in an earlier patch, as well as adding
a couple more tests to ensure we have appropriate coverage.  Ensure
that collisions are detected, regardless of whether there is a
difference in opinion on whether the member name is optional.

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 a7f5966b29 qapi: Support (subset of) \u escapes in strings
The handling of \ inside QAPI strings was less than ideal, and
really only worked JSON's \/, \\, \", and our extension of \'
(an obvious extension, when you realize we use '' instead of ""
for strings).  For other things, like '\n', it resulted in a
literal 'n' instead of a newline.

Of course, at the moment, we really have no use for escaped
characters, as QAPI has to map to C identifiers, and we currently
support ASCII only for that.  But down the road, we may add
support for default values for string parameters to a command
or struct; if that happens, it would be nice to correctly support
all JSON escape sequences, such as \n or \uXXXX.  This gets us
closer, by supporting Unicode escapes in the ASCII range.

Since JSON does not require \OCTAL or \xXX escapes, and our QMP
implementation does not understand them either, I intentionally
reject it here, but it would be an easy addition if we desired it.
Likewise, intentionally refusing the NUL byte means we don't have
to worry about C strings being shorter than the qapi input.

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 6b5abc7df7 qapi: Drop support for inline nested types
A future patch will be using a 'name':{dictionary} entry in the
QAPI schema to specify a default value for an optional argument
(see previous commit messages for more details why); but existing
use of inline nested structs conflicts with that goal. Now that
all commands have been changed to avoid inline nested structs,
nuke support for them, and turn it into a hard error. Update the
testsuite to reflect tighter parsing rules.

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 6446a59276 qapi: Drop tests for inline nested structs
A future patch will be using a 'name':{dictionary} entry in the
QAPI schema to specify a default value for an optional argument;
but existing use of inline nested structs conflicts with that goal.

More precisely, a definition in the QAPI schema associates a name
with a set of properties:

Example 1: { 'struct': 'Foo', 'data': { MEMBERS... } }
associates the global name 'Foo' with properties (meta-type struct)
and MEMBERS...

Example 2: 'mumble': TYPE
within MEMBERS... above associates 'mumble' with properties (type
TYPE) and (optional false) within type Foo

The syntax of example 1 is extensible; if we need another property,
we add another name/value pair to the dictionary (such as
'base':TYPE).  The syntax of example 2 is not extensible, because
the right hand side can only be a type.

We have used name encoding to add a property: "'*mumble': 'int'"
associates 'mumble' with (type int) and (optional true).  Nice,
but doesn't scale.  So the solution is to change our existing uses
to be syntactic sugar to an extensible form:

   NAME: TYPE   --> NAME:  { 'type': TYPE, 'optional': false }
   *ONAME: TYPE --> ONAME: { 'type': TYPE, 'optional': true }

This patch fixes the testsuite to avoid inline nested types, by
breaking the nesting into explicit types; it means that the type
is now boxed instead of unboxed in C code, but makes no difference
on the wire (and if desired, a later patch could change the
generator to not do so much boxing in C).  When touching code to
add new allocations, also convert existing allocations to
consistently prefer typesafe g_new0 over g_malloc0 when a type
name is involved.

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 b6fcf32d9b qapi: Merge UserDefTwo and UserDefNested in tests
In the testsuite, UserDefTwo and UserDefNested were identical
structs other than the member names.  Reduce code duplication by
having just one type, and choose names that also favor reuse.
This will also make it easier for a later patch to get rid of
inline nested types in QAPI.  When touching code related to
allocations, convert g_malloc0(sizeof(Type)) to the more typesafe
g_new0(Type, 1).

Ensure that 'make check-qapi-schema check-unit' still passes.

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 895a2a80e0 qapi: Use 'struct' instead of 'type' in schema
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.  Do the bulk of
the conversion to "struct" in qapi schema, with a fairly
mechanical:

for f in `find -name '*.json'; do sed -i "s/'type'/'struct'/"; done

followed by manually filtering out the places where we have a
'type' embedded in 'data'.  Then tweak a couple of tests whose
output changes slightly due to longer lines.

I also verified that the generated files for QMP and QGA (such
as qmp-commands.h) are the same before and after, as assurance
that I didn't leave in any accidental member name changes.

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