Re: [Qemu-devel] [PATCH v5 13/28] qapi: Add some expr tests

[Markus Armbruster]

Eric Blake <address@hidden> writes:

> Demonstrate that the qapi generator doesn't deal well with
> expressions that aren't up to par. Later patches will improve
> the expected results as the generator is made stricter.  Only
> one of the added tests actually behaves sanely at rejecting
> obvious problems.
>
> Note that in some cases, we reject bad QAPI merely because our
> pseudo-JSON parser does not yet know how to parse numbers.  This
> series does not address that, but when a later series adds support
> for numeric defaults of integer fields, the testsuite will ensure
> that we don't lose the error (and hopefully that the error
> message quality is improved).
>
> Signed-off-by: Eric Blake <address@hidden>
[...]
> new file mode 100644
> index 0000000..e69de29
> diff --git a/tests/qapi-schema/event-case.exit 
> b/tests/qapi-schema/event-case.exit
> new file mode 100644
> index 0000000..573541a
> --- /dev/null
> +++ b/tests/qapi-schema/event-case.exit
> @@ -0,0 +1 @@
> +0
> diff --git a/tests/qapi-schema/event-case.json 
> b/tests/qapi-schema/event-case.json
> new file mode 100644
> index 0000000..52dfc3a
> --- /dev/null
> +++ b/tests/qapi-schema/event-case.json
> @@ -0,0 +1,2 @@
> +# FIXME: we should reject an event name that is not all caps
> +{ 'event': 'oops' }

qapi-code-gen.txt documents the naming conventions:

    Types, commands, and events share a common namespace.  Therefore,
    generally speaking, type definitions should always use CamelCase for
    user-defined type names, while built-in types are lowercase. Type
    definitions should not end in 'Kind', as this namespace is used for
    creating implicit C enums for visiting union types.  Command names,
    and field names within a type, should be all lower case with words
    separated by a hyphen.  However, some existing older commands and
    complex types use underscore; when extending such expressions,
    consistency is preferred over blindly avoiding underscore.  Event
    names should be ALL_CAPS with words separated by underscore.  The
    special string '**' appears for some commands that manually perform
    their own type checking rather than relying on the type-safe code
    produced by the qapi code generators.

We should either enforce the conventions consistently, or not at all.

Enforcing them makes certain kinds of name clashes in generated C
impossible.  If we don't enforce them, we should catch the clashes.

Since I haven't read to the end of your series, I have to ask: do you
intend to enforce them?

> diff --git a/tests/qapi-schema/event-case.out 
> b/tests/qapi-schema/event-case.out
> new file mode 100644
> index 0000000..3764bc7
> --- /dev/null
> +++ b/tests/qapi-schema/event-case.out
> @@ -0,0 +1,3 @@
> +[OrderedDict([('event', 'oops')])]
> +[]
> +[]
[...]