Commit Graph

5 Commits

Author SHA1 Message Date
Markus Armbruster 2ab218aad6 qapi: Change frontend error messages to start with lower case
Starting error messages with a capital letter complicates things when
text can get interpolated both at the beginning and in the middle of
an error message.  The next patch will do that.  Switch to lower case
to keep it simpler.

For what it's worth, the GNU Coding Standards advise the message
"should not begin with a capital letter when it follows a program name
and/or file name, because that isn’t the beginning of a sentence. (The
sentence conceptually starts at the beginning of the line.)"

While there, avoid breaking lines containing multiple arguments in the
middle of an argument.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190927134639.4284-7-armbru@redhat.com>
2019-09-28 17:17:18 +02:00
Markus Armbruster 7be6c51194 qapi: Prefix frontend errors with an "in definition" line
We take pains to include the offending expression in error messages,
e.g.

    tests/qapi-schema/alternate-any.json:2: alternate 'Alt' member 'one' cannot use type 'any'

But not always:

    tests/qapi-schema/enum-if-invalid.json:2: 'if' condition must be a string or a list of strings

Instead of improving them one by one, report the offending expression
whenever it is known, like this:

    tests/qapi-schema/enum-if-invalid.json: In enum 'TestIfEnum':
    tests/qapi-schema/enum-if-invalid.json:2: 'if' condition must be a string or a list of strings

Error messages that mention the offending expression become a bit
redundant, e.g.

    tests/qapi-schema/alternate-any.json: In alternate 'Alt':
    tests/qapi-schema/alternate-any.json:2: alternate 'Alt' member 'one' cannot use type 'any'

I'll take care of that later in this series.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190927134639.4284-5-armbru@redhat.com>
2019-09-28 17:17:18 +02:00
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
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 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