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qemu-e2k/tests/qapi-schema/base-cycle-direct.json

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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>
2015-12-02 06:20:59 +01:00
# we reject a loop in base classes
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>
2017-01-13 15:41:29 +01:00
##
# @Loopy:
##
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>
2015-12-02 06:20:59 +01:00
{ 'struct': 'Loopy', 'base': 'Loopy', 'data': {} }