Commit Graph

3 Commits

Author SHA1 Message Date
Markus Armbruster 6974ccd542 qapi.py: Fix schema parser to check syntax systematically
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: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1374939721-7876-7-git-send-email-armbru@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-07-29 10:37:11 -05:00
Markus Armbruster c7a3f25200 qapi.py: Restructure lexer and parser
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: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1374939721-7876-4-git-send-email-armbru@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-07-29 10:37:10 -05:00
Markus Armbruster 98626572f1 tests: QAPI schema parser tests
The parser handles erroneous input badly.  To be improved shortly.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1374939721-7876-2-git-send-email-armbru@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-07-29 10:37:10 -05:00