2015-05-04 18:05:13 +03:00
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# we reject an alternate with unknown type in branch
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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 17:41:29 +03:00
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##
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# @Alt:
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##
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2015-05-04 18:05:13 +03:00
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{ 'alternate': 'Alt',
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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>
2015-09-30 01:21:05 +03:00
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'data': { 'unknown': 'MissingType', 'i': 'int' } }
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