]> git.proxmox.com Git - mirror_qemu.git/commit - docs/qapi-code-gen.txt
qapi: Reserve 'q_*' and 'has_*' member names
authorEric Blake <eblake@redhat.com>
Mon, 26 Oct 2015 22:34:44 +0000 (16:34 -0600)
committerMarkus Armbruster <armbru@redhat.com>
Mon, 2 Nov 2015 07:30:26 +0000 (08:30 +0100)
commit9fb081e0b98409556d023c7193eeb68947cd1211
treec19eeaa3eed47ee66a97a4c14a421c61e2055ff6
parent255960dd374d4497d6ea537305f1b0d8a3433789
qapi: Reserve 'q_*' and 'has_*' member names

c_name() produces names starting with 'q_' when protecting a
dictionary member name that would fail to directly compile, but
in doing so can cause clashes with any member name already
beginning with 'q-' or 'q_'.  Likewise, we create a C name 'has_'
for any optional member that can clash with any member name
beginning with 'has-' or 'has_'.

Technically, rather than blindly reserving the namespace,
we could try to complain about user names only when an actual
collision occurs, or even teach c_name() how to munge names
to avoid collisions.  But it is not trivial, especially when
collisions can occur across multiple types (such as via
inheritance or flat unions).  Besides, no existing .json
files are trying to use these names.  So it's easier to just
outright forbid the potential for collision.  We can always
relax things in the future if a real need arises for QMP to
express member names that have been forbidden here.

'has_' only has to be reserved for struct/union member names,
while 'q_' is reserved everywhere (matching the fact that
only members can be optional, while we use c_name() for munging
both members and entities).  Note that we could relax 'q_'
restrictions on entities independently from member names; for
example, c_name('qmp_' + 'unix') would result in a different
function name than our current 'qmp_' + c_name('unix').

Update and add tests to cover the new error messages.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-6-git-send-email-eblake@redhat.com>
[Consistently pass protect=False to c_name(); commit message tweaked
slightly]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
14 files changed:
docs/qapi-code-gen.txt
scripts/qapi.py
tests/qapi-schema/reserved-command-q.err
tests/qapi-schema/reserved-command-q.exit
tests/qapi-schema/reserved-command-q.json
tests/qapi-schema/reserved-command-q.out
tests/qapi-schema/reserved-member-has.err
tests/qapi-schema/reserved-member-has.exit
tests/qapi-schema/reserved-member-has.json
tests/qapi-schema/reserved-member-has.out
tests/qapi-schema/reserved-member-q.err
tests/qapi-schema/reserved-member-q.exit
tests/qapi-schema/reserved-member-q.json
tests/qapi-schema/reserved-member-q.out