Re: [PATCH v3 06/13] qapi/parser: remove FIXME comment from _append_body_line

[Markus Armbruster <armbru@redhat.com>]

John Snow <jsnow@redhat.com> writes:

> True, we do not check the validity of this symbol -- but we don't check
> the validity of definition names during parse, either -- that happens
> later, during the expr check. I don't want to introduce a dependency on
> expr.py:check_name_str here and introduce a cycle.
>
> Instead, rest assured that a documentation block is required for each
> definition. This requirement uses the names of each section to ensure
> that we fulfilled this requirement.
>
> e.g., let's say that block-core.json has a comment block for
> "Snapshot!Info" by accident. We'll see this error message:
>
> In file included from ../../qapi/block.json:8:
> ../../qapi/block-core.json: In struct 'SnapshotInfo':
> ../../qapi/block-core.json:38: documentation comment is for 'Snapshot!Info'
>
> That's a pretty decent error message.
>
> Now, let's say that we actually mangle it twice, identically:
>
> ../../qapi/block-core.json: In struct 'Snapshot!Info':
> ../../qapi/block-core.json:38: struct has an invalid name
>
> That's also pretty decent. If we forget to fix it in both places, we'll
> just be back to the first error.
>
> Therefore, let's just drop this FIXME and adjust the error message to
> not imply a more thorough check than is actually performed.
>
> Signed-off-by: John Snow <jsnow@redhat.com>
> ---
>  scripts/qapi/parser.py                 | 6 ++++--
>  tests/qapi-schema/doc-empty-symbol.err | 2 +-
>  2 files changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/scripts/qapi/parser.py b/scripts/qapi/parser.py
> index 2f93a752f66..52748e8e462 100644
> --- a/scripts/qapi/parser.py
> +++ b/scripts/qapi/parser.py
> @@ -558,9 +558,11 @@ def _append_body_line(self, line):
>                  raise QAPIParseError(
>                      self._parser, "extra whitespace around symbol declaration")
>              self.symbol = line[1:-1]
> -            # FIXME invalid names other than the empty string aren't flagged
> +            # Invalid names are not checked here, but the name provided MUST
> +            # match the following definition, which *is* validated.
>              if not self.symbol:
> -                raise QAPIParseError(self._parser, "invalid name")
> +                raise QAPIParseError(
> +                    self._parser, "doc symbol name cannot be blank")

"blank" feels like "empty or just whitespace" to me.  We actually mean
"empty".

What about "name required after @"?

>          elif self.symbol:
>              # This is a definition documentation block
>              name = line.split(' ', 1)[0]
> diff --git a/tests/qapi-schema/doc-empty-symbol.err b/tests/qapi-schema/doc-empty-symbol.err
> index 81b90e882a7..a4981ee28ea 100644
> --- a/tests/qapi-schema/doc-empty-symbol.err
> +++ b/tests/qapi-schema/doc-empty-symbol.err
> @@ -1 +1 @@
> -doc-empty-symbol.json:4:1: invalid name
> +doc-empty-symbol.json:4:1: doc symbol name cannot be blank