[Qemu-devel] [PATCH v10 00/30] qapi member collision (post-introspection cleanups, subset C')

[Eric Blake]

No pending prerequisites; based on qemu.git master

Also available as a tag at this location:
git fetch git://repo.or.cz/qemu/ericb.git qapi-cleanupv9c

and will soon be part of my branch with the rest of the v5 series, at:
http://repo.or.cz/qemu/ericb.git/shortlog/refs/heads/qapi

v10 notes:
Split several patches, redo the middle patches from Markus to be
back in the order they were first posted, some fallout change to
my patches due to the nicer pattern of minimizing conditionals
inside .check(), by instead calling .check_clash() as needed.
Change data->err magic in tests to instead use a new helper
error_free_or_abort(). Add a patch that would prevent qapi
case-insensitive clashes.

I am redoing my subset boundaries slightly: patches 23-27 of
v9 (updating the alternate layout) will be delayed to subset D,
and 2 other patches previously posted in subset D are now here
(turning qapi clash checking into actual error messages), so
the subject line of this cover letter is slightly different.

Hopefully, we are converging on something that will be ready
for a pull request, especially for the earlier patches of this
subset.

Backport diff in relation to v9:

001/30:[----] [--] 'qapi: Use generated TestStruct machinery in tests'
002/30:[----] [--] 'qapi: Strengthen test of TestStructList'
003/30:[down] 'qobject: Protect against use-after-free in qobject_decref()'
004/30:[down] 'qapi: Share test_init code in test-qmp-input*'
005/30:[0001] [FC] 'qapi: Plug leaks in test-qmp-*'
006/30:[down] 'qapi: Simplify non-error testing in test-qmp-*'
007/30:[down] 'qapi: Simplify error cleanup in test-qmp-*'
008/30:[----] [--] 'qapi: More tests of alternate output'
009/30:[0010] [FC] 'qapi: Test failure in middle of array parse'
010/30:[0025] [FC] 'qapi: More tests of input arrays'
011/30:[----] [--] 'qapi: Provide nicer array names in introspection'
012/30:[0014] [FC] 'qapi-introspect: Document lack of sorting'
013/30:[----] [--] 'qapi: Track simple union tag in object.local_members'
014/30:[----] [--] 'qapi-types: Consolidate gen_struct() and gen_union()'
015/30:[----] [--] 'qapi-types: Simplify gen_struct_field[s]'
016/30:[0005] [FC] 'qapi: Drop obsolete tag value collision assertions'
017/30:[0002] [FC] 'qapi: Simplify QAPISchemaObjectTypeMember.check()'
018/30:[down] 'qapi: Clean up after previous commit'
019/30:[----] [-C] 'qapi: Fix up commit 7618b91's clash sanity checking change'
020/30:[0002] [FC] 'qapi: Eliminate QAPISchemaObjectType.check() variable 
members'
021/30:[----] [--] 'qapi: Factor out QAPISchemaObjectTypeMember.check_clash()'
022/30:[----] [-C] 'qapi: Simplify QAPISchemaObjectTypeVariants.check()'
023/30:[0023] [FC] 'qapi: Check for qapi collisions of flat union branches'
024/30:[0013] [FC] 'qapi: Factor out QAPISchemaObjectType.check_clash()'
025/30:[down] 'qapi: Hoist tag collision check to Variants.check()'
026/30:[----] [--] 'qapi: Remove outdated tests related to QMP/branch 
collisions'
027/30:[down] 'qapi: Track owner of each object member'
028/30:[down] 'qapi: Detect collisions in C member names'
029/30:[down] 'cpu: Convert CpuInfo into flat union'
030/30:[down] 'qapi: Forbid case-insensitive clashes'


v9 notes:
https://lists.gnu.org/archive/html/qemu-devel/2015-11/msg00652.html
More patches added, and several reorganized.  Lots of new patches
from Markus, although not in the order originally proposed.

The first 8 patches are fairly straightforward, and could probably
be taken as-is. Patch 9 is a rewrite of v8 4/17, but in the opposite
direction (document that no sorting is done, rather than attempting
to sort), so it may need further fine-tuning.  Patches 12-21
represents a fusion of Markus' and my attempts to rewrite v5 7/17
into a more-reviewable set of patches, and caused further churn
later in the series.

Patch 23 still uses tag_member.type == None; I ran out of time to
work on Markus' idea of providing an instance of QAPISchemaBuiltinType
to fill the role for 'qtype_code' without being exposed through .json
files and without breaking the invariant of a valid member.type after
check(), and wanted to get the rest of the series started under revew.
So I may need a followup patch or even a v10 of the later half of
this series after exploring that idea more.

v8 notes:
https://lists.gnu.org/archive/html/qemu-devel/2015-10/msg06674.html
Minor changes when rebasing to latest, improved commit messages in
a few places, plus the addition of a few new patches. Markus started
reviewing v7, but hadn't gotten very far.

v7 notes:
https://lists.gnu.org/archive/html/qemu-devel/2015-10/msg04112.html
Patches 1-3 of the previous round have moved to subset B; patch 7
is gone, and a couple of new patches are present in this round. The
latest version of subset B made it much easier to reason about
collision detection (namely, tag values can't collide with QMP values
thanks to a named rather than anonymous union in the C type), and I
like how things turned out.  I suspect the hardest part of the review
will be patches 5/14 and 7/14, although none of this has really
had much review in any earlier versions.

v6 notes:
https://lists.gnu.org/archive/html/qemu-devel/2015-10/msg01980.html
Add some patches and rebase onto work on subset B. Rearrange some
patches from v5 (this set includes 17-20, 23, 25-27). Backport diff
gets a bit confused by one patch title changing.

Not much direct review comments, although some of the changes here
are updated based on comments made on other patches in the v5 series.

Subset D (and more?) will come later.

In v5:
https://lists.gnu.org/archive/html/qemu-devel/2015-09/msg05410.html
I _did_ rearrange patches to try and group related features:

1-2: Groundwork cleanups
3-5: Add more test cases
6-16: Front-end cleanups
17-18: Introspection output cleanups
19-20: 'alternate' type cleanups
21-29: qapi visitor cleanups
30-45: qapi-ify netdev_add
46: add qapi shorthand for flat unions

Lots of fixes based on additional testing, and rebased to
track other changes that happened in the meantime.  The series
is huge; I can split off smaller portions as requested.

In v4:
https://lists.gnu.org/archive/html/qemu-devel/2015-09/msg02580.html
add some more clean up patches
rebase to Markus' recent work
pull in part of Zoltán's work to make netdev_add a flat union,
further enhancing it to be introspectible

I might be able to rearrange some of these patches, or separate
it into smaller independent series, if requested; but I'm
posting now to get review started.

In v3:
https://lists.gnu.org/archive/html/qemu-devel/2015-08/msg02059.html
redo cleanup of dealloc of partial struct
add patches to make all visit_type_*() avoid leaks on failure
add patches to allow boxed command arguments and events

In v2:
https://lists.gnu.org/archive/html/qemu-devel/2015-08/msg00900.html
rebase to Markus' v3 series
rework how comments are emitted for fields inherited from base
additional patches added for deleting colliding 'void *data'
documentation updates to match code changes

v1 was here:
https://lists.gnu.org/archive/html/qemu-devel/2015-07/msg05266.html
https://lists.gnu.org/archive/html/qemu-devel/2015-07/msg05325.html

Eric Blake (23):
  qapi: Use generated TestStruct machinery in tests
  qapi: Strengthen test of TestStructList
  qobject: Protect against use-after-free in qobject_decref()
  qapi: Share test_init code in test-qmp-input*
  qapi: Plug leaks in test-qmp-*
  qapi: Simplify non-error testing in test-qmp-*
  qapi: Simplify error cleanup in test-qmp-*
  qapi: More tests of alternate output
  qapi: Test failure in middle of array parse
  qapi: More tests of input arrays
  qapi: Provide nicer array names in introspection
  qapi-introspect: Document lack of sorting
  qapi: Track simple union tag in object.local_members
  qapi-types: Consolidate gen_struct() and gen_union()
  qapi-types: Simplify gen_struct_field[s]
  qapi: Check for qapi collisions of flat union branches
  qapi: Factor out QAPISchemaObjectType.check_clash()
  qapi: Hoist tag collision check to Variants.check()
  qapi: Remove outdated tests related to QMP/branch collisions
  qapi: Track owner of each object member
  qapi: Detect collisions in C member names
  cpu: Convert CpuInfo into flat union
  qapi: Forbid case-insensitive clashes

Markus Armbruster (7):
  qapi: Drop obsolete tag value collision assertions
  qapi: Simplify QAPISchemaObjectTypeMember.check()
  qapi: Clean up after previous commit
  qapi: Fix up commit 7618b91's clash sanity checking change
  qapi: Eliminate QAPISchemaObjectType.check() variable members
  qapi: Factor out QAPISchemaObjectTypeMember.check_clash()
  qapi: Simplify QAPISchemaObjectTypeVariants.check()

 cpus.c                                             |  31 ++-
 docs/qapi-code-gen.txt                             |  31 ++-
 hmp.c                                              |  30 ++-
 include/qapi/qmp/qobject.h                         |   1 +
 qapi-schema.json                                   | 120 +++++++--
 qapi/introspect.json                               |  17 +-
 scripts/qapi-introspect.py                         |   8 +-
 scripts/qapi-types.py                              |  68 ++----
 scripts/qapi-visit.py                              |   9 +-
 scripts/qapi.py                                    | 135 ++++++----
 tests/Makefile                                     |   4 +-
 tests/qapi-schema/args-case-clash.err              |   1 +
 ...{union-clash-type.exit => args-case-clash.exit} |   0
 tests/qapi-schema/args-case-clash.json             |   5 +
 .../{union-clash-type.out => args-case-clash.out}  |   0
 tests/qapi-schema/args-name-clash.err              |   1 +
 tests/qapi-schema/args-name-clash.exit             |   2 +-
 tests/qapi-schema/args-name-clash.json             |   6 +-
 tests/qapi-schema/args-name-clash.out              |   6 -
 tests/qapi-schema/flat-union-clash-branch.err      |   0
 tests/qapi-schema/flat-union-clash-branch.exit     |   1 -
 tests/qapi-schema/flat-union-clash-branch.json     |  18 --
 tests/qapi-schema/flat-union-clash-branch.out      |  14 --
 tests/qapi-schema/flat-union-clash-type.err        |   1 -
 tests/qapi-schema/flat-union-clash-type.exit       |   1 -
 tests/qapi-schema/flat-union-clash-type.json       |  14 --
 tests/qapi-schema/flat-union-clash-type.out        |   0
 tests/qapi-schema/qapi-schema-test.json            |   6 +-
 tests/qapi-schema/qapi-schema-test.out             |  15 +-
 tests/qapi-schema/union-clash-data.out             |   1 +
 tests/qapi-schema/union-clash-type.err             |   1 -
 tests/qapi-schema/union-clash-type.json            |   9 -
 tests/qapi-schema/union-empty.out                  |   1 +
 tests/test-qmp-commands.c                          |   8 +-
 tests/test-qmp-common.h                            |  22 ++
 tests/test-qmp-event.c                             |   1 +
 tests/test-qmp-input-strict.c                      | 131 +++-------
 tests/test-qmp-input-visitor.c                     | 272 +++++++++------------
 tests/test-qmp-output-visitor.c                    | 151 +++---------
 tests/test-visitor-serialization.c                 |  76 ++----
 40 files changed, 570 insertions(+), 648 deletions(-)
 create mode 100644 tests/qapi-schema/args-case-clash.err
 rename tests/qapi-schema/{union-clash-type.exit => args-case-clash.exit} (100%)
 create mode 100644 tests/qapi-schema/args-case-clash.json
 rename tests/qapi-schema/{union-clash-type.out => args-case-clash.out} (100%)
 delete mode 100644 tests/qapi-schema/flat-union-clash-branch.err
 delete mode 100644 tests/qapi-schema/flat-union-clash-branch.exit
 delete mode 100644 tests/qapi-schema/flat-union-clash-branch.json
 delete mode 100644 tests/qapi-schema/flat-union-clash-branch.out
 delete mode 100644 tests/qapi-schema/flat-union-clash-type.err
 delete mode 100644 tests/qapi-schema/flat-union-clash-type.exit
 delete mode 100644 tests/qapi-schema/flat-union-clash-type.json
 delete mode 100644 tests/qapi-schema/flat-union-clash-type.out
 delete mode 100644 tests/qapi-schema/union-clash-type.err
 delete mode 100644 tests/qapi-schema/union-clash-type.json
 create mode 100644 tests/test-qmp-common.h

-- 
2.4.3