[RFC PATCH 00/19] Configurable policy for handling deprecated interfaces

[Markus Armbruster]

This series is RFC because it's incomplete, and the warning idea in
PATCH 18 is half-baked.  I'm soliciting feed back from the management
application crowd: is this going into a useful direction?

The series adresses only deprecated commands and events.  Good enough
to demonstrate the ideas, I think.  A complete solution should
additionally cover arguments and return values.  Feels feasible to me.

New option -compat deprecated-input=<in-policy>,deprecated-output=out-policy
configures the policy.  Available input policies:

* accept: Accept deprecated commands with a warning (default)
* reject: Reject deprecated commands
* crash: Crash on deprecated command

Available output policies:

* accept: Emit deprecated events (default)
* hide: Suppress deprecated events

See also last item of
    Subject: Minutes of KVM Forum BoF on deprecating stuff
    Date: Fri, 26 Oct 2018 16:03:51 +0200
    Message-ID: <address@hidden>
    https://lists.nongnu.org/archive/html/qemu-devel/2018-10/msg05828.html


Markus Armbruster (19):
  tests/test-qmp-cmds: Factor out qmp_dispatch() test helpers
  tests/test-qmp-cmds: Check responses more thoroughly
  tests/test-qmp-cmds: Simplify test data setup
  tests/test-qmp-event: Simplify test data setup
  tests/test-qmp-event: Use qobject_is_equal()
  tests/test-qmp-event: Check event is actually emitted
  qapi: Add feature flags to remaining definitions
  qapi: Consistently put @features parameter right after @ifcond
  qapi: Inline do_qmp_dispatch() into qmp_dispatch()
  qapi: Simplify how qmp_dispatch() deals with QCO_NO_SUCCESS_RESP
  qapi: Simplify how qmp_dispatch() gets the request ID
  qapi: Replace qmp_dispatch()'s TODO comment by an explanation
  qapi: New special feature flag "deprecated"
  qemu-options: New -compat to set policy for "funny" interfaces
  qapi: Mark deprecated QMP commands with feature 'deprecated'
  qapi: Implement -compat deprecated-input=reject for commands
  qapi: Implement -compat deprecated-input=crash for commands
  qapi: Include a warning in the response to a deprecated command
  qapi: Implement -compat deprecated-output=hide for events

 docs/devel/qapi-code-gen.txt                  |  21 +-
 tests/qapi-schema/doc-good.texi               |  32 ++-
 qapi/common.json                              |  48 ++++
 qapi/introspect.json                          |  28 ++-
 qapi/machine.json                             |  24 +-
 qapi/migration.json                           |  36 ++-
 qapi/misc.json                                |  25 +-
 include/qapi/compat-policy.h                  |  20 ++
 include/qapi/qmp/dispatch.h                   |   1 +
 qapi/qmp-dispatch.c                           | 140 +++++++-----
 tests/test-qmp-cmds.c                         | 216 +++++++++++-------
 tests/test-qmp-event.c                        | 181 ++++-----------
 vl.c                                          |  17 ++
 qemu-options.hx                               |  24 ++
 scripts/qapi/commands.py                      |  16 +-
 scripts/qapi/doc.py                           |  16 +-
 scripts/qapi/events.py                        |  16 +-
 scripts/qapi/expr.py                          |  11 +-
 scripts/qapi/introspect.py                    |  41 ++--
 scripts/qapi/schema.py                        | 138 ++++++-----
 scripts/qapi/types.py                         |   8 +-
 scripts/qapi/visit.py                         |   8 +-
 tests/Makefile.include                        |   1 +
 tests/qapi-schema/alternate-base.err          |   2 +-
 tests/qapi-schema/doc-good.json               |  18 +-
 tests/qapi-schema/doc-good.out                |  20 +-
 .../qapi-schema/features-deprecated-type.err  |   2 +
 .../qapi-schema/features-deprecated-type.json |   3 +
 .../qapi-schema/features-deprecated-type.out  |   0
 tests/qapi-schema/qapi-schema-test.json       |  31 ++-
 tests/qapi-schema/qapi-schema-test.out        |  29 ++-
 tests/qapi-schema/test-qapi.py                |  19 +-
 32 files changed, 731 insertions(+), 461 deletions(-)
 create mode 100644 include/qapi/compat-policy.h
 create mode 100644 tests/qapi-schema/features-deprecated-type.err
 create mode 100644 tests/qapi-schema/features-deprecated-type.json
 create mode 100644 tests/qapi-schema/features-deprecated-type.out

-- 
2.21.0