Since enum based discriminators provide better type-safety and
ensure that future qapi additions do not forget to adjust dependent
unions, forbid using string as discriminator from now on.
Signed-off-by: NWenchao Xia <wenchaoqemu@gmail.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

By default, any union will automatically generate a enum type as
"[UnionName]Kind" in C code, and it is duplicated when the discriminator
is specified as a pre-defined enum type in schema. After this patch,
the pre-defined enum type will be really used as the switch case
condition in generated C code, if discriminator is an enum field.
Signed-off-by: NWenchao Xia <wenchaoqemu@gmail.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

Since line info is remembered as QAPISchema.line now, this patch
uses it as additional info for every expr in QAPISchema inside qapi.py,
then improves error message with it in checking of exprs.

For common union the patch will check whether base is a valid complex
type if specified. For flat union it will check whether base presents,
whether discriminator is found in base, whether the key of every branch
is correct when discriminator is an enum type.
Signed-off-by: NWenchao Xia <wenchaoqemu@gmail.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

It is bad that same key was specified twice, especially when a union has
two branches with same condition. This patch can prevent it.
Signed-off-by: NWenchao Xia <wenchaoqemu@gmail.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

Later other scripts will need to check the enum values.
Signed-off-by: NWenchao Xia <wenchaoqemu@gmail.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

The test demonstrates a generator bug: the generated struct
UserDefFlatUnion doesn't include members for the indirect base
UserDefZero.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

According to commit 4f193e34
("tests: Use qapi-schema-test.json as schema parser test")
the "tests/qapi-schema/qapi-schema-test.out" file must be updated as well.
Signed-off-by: NLaszlo Ersek <lersek@redhat.com>
Tested-by: NWanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Message-id: 1374939721-7876-10-git-send-email-armbru@redhat.com
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Report syntax error instead of crashing.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Message-id: 1374939721-7876-8-git-send-email-armbru@redhat.com
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Fixes at least the following parser bugs:

* accepts any token in place of a colon

* treats comma as optional

* crashes when closing braces or brackets are missing
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Message-id: 1374939721-7876-7-git-send-email-armbru@redhat.com
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Message-id: 1374939721-7876-6-git-send-email-armbru@redhat.com
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Message-id: 1374939721-7876-5-git-send-email-armbru@redhat.com
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

The parser has a rather unorthodox structure:

    Until EOF:

        Read a section:

            Generator function get_expr() yields one section after the
            other, as a string.  An unindented, non-empty line that
            isn't a comment starts a new section.

        Lexing:

            Split section into a list of tokens (strings), with help
            of generator function tokenize().

        Parsing:

            Parse the first expression from the list of tokens, with
            parse(), throw away any remaining tokens.

            In parse_schema(): record value of an enum, union or
            struct key (if any) in the appropriate global table,
            append expression to the list of expressions.

    Return list of expressions.

Known issues:

(1) Indentation is significant, unlike in real JSON.

(2) Neither lexer nor parser have any idea of source positions.  Error
    reporting is hard, let's go shopping.

(3) The one error we bother to detect, we "report" via raise.

(4) The lexer silently ignores invalid characters.

(5) If everything in a section gets ignored, the parser crashes.

(6) The lexer treats a string containing a structural character exactly
    like the structural character.

(7) Tokens trailing the first expression in a section are silently
    ignored.

(8) The parser accepts any token in place of a colon.

(9) The parser treats comma as optional.

(10) parse() crashes on unexpected EOF.

(11) parse_schema() crashes when a section's expression isn't a JSON
    object.

Replace this piece of original art by a thoroughly unoriginal design.
Takes care of (1), (2), (5), (6) and (7), and lays the groundwork for
addressing the others.  Generated source files remain unchanged.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Message-id: 1374939721-7876-4-git-send-email-armbru@redhat.com
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Message-id: 1374939721-7876-3-git-send-email-armbru@redhat.com
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

The parser handles erroneous input badly.  To be improved shortly.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Message-id: 1374939721-7876-2-git-send-email-armbru@redhat.com
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>