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| author | Eric Blake <eblake@redhat.com> | 2015-07-30 17:07:17 -0600 |
|---|---|---|
| committer | Markus Armbruster <armbru@redhat.com> | 2015-09-04 15:47:14 +0200 |
| commit | ca56a822dd538017715345cbbe1f8829e0cc2742 (patch) | |
| tree | ddbde6c3a1ebddf1930f57a309fdc9a64bfdf55e /scripts | |
| parent | 2f52e20597ebd55ede668b2b7d162a84f419b03e (diff) | |
| download | qemu-ca56a822dd538017715345cbbe1f8829e0cc2742.tar.gz qemu-ca56a822dd538017715345cbbe1f8829e0cc2742.tar.bz2 qemu-ca56a822dd538017715345cbbe1f8829e0cc2742.zip | |
qapi: Document shortcoming with union 'data' branch
Add a FIXME to remind us to fully audit whether removing the
'void *data' branch of each qapi union type can be done safely.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1438297637-26789-1-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Diffstat (limited to 'scripts')
| -rw-r--r-- | scripts/qapi-types.py | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py index 82141cdec3..8444f9836a 100644 --- a/scripts/qapi-types.py +++ b/scripts/qapi-types.py @@ -219,6 +219,14 @@ struct %(name)s ''', discriminator_type_name=c_name(discriminator_type_name)) + # FIXME: What purpose does data serve, besides preventing a union that + # has a branch named 'data'? We use it in qapi-visit.py to decide + # whether to bypass the switch statement if visiting the discriminator + # failed; but since we 0-initialize structs, and cannot tell what + # branch of the union is in use if the discriminator is invalid, there + # should not be any data leaks even without a data pointer. Or, if + # 'data' is merely added to guarantee we don't have an empty union, + # shouldn't we enforce that at .json parse time? ret += mcgen(''' union { /* union tag is @%(c_name)s */ void *data; |