Re: [PATCH] qapi: Fix crash on missing enum member name

[John Snow]

On 6/16/21 3:21 AM, Markus Armbruster wrote:
> New test case enum-dict-no-name.json crashes:
>
>      $ python3 scripts/qapi-gen.py tests/qapi-schema/enum-dict-no-name.json
>      Traceback (most recent call last):
>      [...]
>        File "/work/armbru/qemu/scripts/qapi/expr.py", line 458, in check_enum
>         member_name = member['name']
>      KeyError: 'name'
>
> Root cause: we try to retrieve member 'name' before we check for
> missing members.  With that fixed, we get the expected error "'data'
> member misses key 'name'".

Whoops! Good spot.

> Fixes: 0825f62c842f2c07c5471391c6d7fd3f4fe83732
> Signed-off-by: Markus Armbruster <armbru@redhat.com>

Reviewed-by: John Snow <jsnow@redhat.com>

> ---
>   scripts/qapi/expr.py                     | 2 +-
>   tests/qapi-schema/enum-dict-no-name.err  | 2 ++
>   tests/qapi-schema/enum-dict-no-name.json | 2 ++
>   tests/qapi-schema/enum-dict-no-name.out  | 0
>   4 files changed, 5 insertions(+), 1 deletion(-)
>   create mode 100644 tests/qapi-schema/enum-dict-no-name.err
>   create mode 100644 tests/qapi-schema/enum-dict-no-name.json
>   create mode 100644 tests/qapi-schema/enum-dict-no-name.out
>
> diff --git a/scripts/qapi/expr.py b/scripts/qapi/expr.py
> index 496f7e0333..cf98923fa6 100644
> --- a/scripts/qapi/expr.py
> +++ b/scripts/qapi/expr.py
> @@ -455,8 +455,8 @@ def check_enum(expr: _JSONObject, info: QAPISourceInfo) -> 
> None:
>                     for m in members]
>       for member in members:
>           source = "'data' member"
> -        member_name = member['name']
>           check_keys(member, info, source, ['name'], ['if'])
> +        member_name = member['name']
>           check_name_is_str(member_name, info, source)
>           source = "%s '%s'" % (source, member_name)
>           # Enum members may start with a digit
> diff --git a/tests/qapi-schema/enum-dict-no-name.err 
> b/tests/qapi-schema/enum-dict-no-name.err
> new file mode 100644
> index 0000000000..3ce0c16987
> --- /dev/null
> +++ b/tests/qapi-schema/enum-dict-no-name.err
> @@ -0,0 +1,2 @@
> +enum-dict-no-name.json: In enum 'Enum':
> +enum-dict-no-name.json:2: 'data' member misses key 'name'
> diff --git a/tests/qapi-schema/enum-dict-no-name.json 
> b/tests/qapi-schema/enum-dict-no-name.json
> new file mode 100644
> index 0000000000..5952a8662e
> --- /dev/null
> +++ b/tests/qapi-schema/enum-dict-no-name.json
> @@ -0,0 +1,2 @@
> +# enum member lacking a name
> +{ 'enum': 'Enum', 'data': [ {} ] }
> diff --git a/tests/qapi-schema/enum-dict-no-name.out 
> b/tests/qapi-schema/enum-dict-no-name.out
> new file mode 100644
> index 0000000000..e69de29bb2