Re: [PATCH 3/6] qapi: Remove wrapper struct for simple unions

[Markus Armbruster]

Marc-André Lureau <marcandre.lureau@gmail.com> writes:

> Hi
>
> On Fri, Oct 23, 2020 at 2:14 PM Kevin Wolf <kwolf@redhat.com> wrote:
>
>> Variants of simple unions are always contained in a wrapper object
>> called 'data' that serves no real use. When mapping a QAPI object to the
>> command line, this becomes very visible to users because they have to
>> add one or more useless 'data.' to many option names.
>>
>> As a first step towards avoiding this painful CLI experience, this gets
>> rid of the 'data' indirection internally: The QAPI parser doesn't use a
>> wrapper object as the variant type any more, so the indirection is
>> removed from the generated C types. As a result, the C type looks the
>> same for flat and simple unions now. A large part of this patch is
>> mechanical conversion of C code to remove the 'data' indirection.
>>
>> Conceptually, the important change is that variants can now have flat
>> and wrapped representations. For a transitioning period, we'll allow
>> variants to support both representations in a later patch. Eventually,
>> the plan is to deprecate and remove wrapped representations entirely,
>> unifying simple and flat unions.
>>
>> The externally visible interfaces stay unchanged: Visitors still expect
>> the 'data' wrappers, and introspection still shows it.
>>
>> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
>>
>
> breaks the build for me:
>
> ../chardev/spice.c: In function ‘qemu_chr_open_spice_vmc’:
> ../chardev/spice.c:261:56: error: ‘ChardevSpiceChannel’ has no member named
> ‘data’
>   261 |     ChardevSpiceChannel *spicevmc = backend->u.spicevmc.data;
>       |                                                        ^
> ../chardev/spice.c: In function ‘qemu_chr_open_spice_port’:
> ../chardev/spice.c:297:55: error: ‘ChardevSpicePort’ has no member named
> ‘data’
>   297 |     ChardevSpicePort *spiceport = backend->u.spiceport.data;
>       |                                                       ^
> ../chardev/spice.c: In function ‘qemu_chr_parse_spice_vmc’:
> ../chardev/spice.c:331:35: error: ‘ChardevSpiceChannel’ has no member named
> ‘data’
>   331 |     spicevmc = backend->u.spicevmc.data =
> g_new0(ChardevSpiceChannel, 1);
>       |                                   ^
> ../chardev/spice.c: In function ‘qemu_chr_parse_spice_port’:
> ../chardev/spice.c:347:37: error: ‘ChardevSpicePort’ has no member named
> ‘data’
>   347 |     spiceport = backend->u.spiceport.data =
> g_new0(ChardevSpicePort, 1);
>       |                                     ^
> ../ui/spice-app.c: In function ‘chr_spice_backend_new’:
> ../ui/spice-app.c:63:20: error: ‘ChardevSpicePort’ has no member named
> ‘data’
>    63 |     be->u.spiceport.data = g_new0(ChardevSpicePort, 1);
>       |                    ^
> ../ui/spice-app.c: In function ‘vc_chr_open’:
> ../ui/spice-app.c:86:20: error: ‘ChardevSpicePort’ has no member named
> ‘data’
>    86 |     be->u.spiceport.data->fqdn = fqdn ?
>       |                    ^
> ../ui/spice-app.c: In function ‘spice_app_display_init’:
> ../ui/spice-app.c:185:20: error: ‘ChardevSpicePort’ has no member named
> ‘data’
>   185 |     be->u.spiceport.data->fqdn = g_strdup("org.qemu.monitor.qmp.0");
>       |                    ^

In addition to that, I get

    /usr/bin/sphinx-build-3 -Dversion=5.1.50 -Drelease= 
-Ddepfile=docs/interop.d -Ddepfile_stamp=docs/interop.stamp -b html -d 
/work/armbru/qemu/bld-x86/docs/interop.p /work/armbru/qemu/docs/interop 
/work/armbru/qemu/bld-x86/docs/interop
    Running Sphinx v2.2.2
    building [mo]: targets for 0 po files that are out of date
    building [html]: targets for 12 source files that are out of date
    updating environment: [new config] 12 added, 0 changed, 0 removed
    reading sources... [  8%] bitmaps
    reading sources... [ 16%] dbus
    reading sources... [ 25%] dbus-vmstate
    reading sources... [ 33%] index
    reading sources... [ 41%] live-block-operations
    reading sources... [ 50%] pr-helper
    reading sources... [ 58%] qemu-ga
    reading sources... [ 66%] qemu-ga-ref
    reading sources... [ 75%] qemu-qmp-ref

    Exception occurred:
      File "/work/armbru/qemu/docs/sphinx/qapidoc.py", line 187, in 
_nodes_for_members
        assert not v.type.base and not v.type.variants
    AttributeError: 'QAPISchemaBuiltinType' object has no attribute 'base'
    The full traceback has been saved in /tmp/sphinx-err-fq8tq1i7.log, if you 
want to report the issue to the developers.
    Please also report this if it was a user error, so that a better error 
message can be provided next time.
    A bug report can be filed in the tracker at 
<https://github.com/sphinx-doc/sphinx/issues>. Thanks!