becceedc4d
There's no reason to do two malloc's for an alternate type visiting a QAPI struct; let's just inline the struct directly as the C union branch of the struct. Surprisingly, no clients were actually using the struct member prior to this patch outside of the testsuite; an earlier patch in the series added some testsuite coverage to make the effect of this patch more obvious. In qapi.py, c_type() gains a new is_unboxed flag to control when we are emitting a C struct unboxed within the context of an outer struct (different from our other two modes of usage with no flags for normal local variable declarations, and with is_param for adding 'const' in a parameter list). I don't know if there is any more pythonic way of collapsing the two flags into a single parameter, as we never have a caller setting both flags at once. Ultimately, we want to also unbox branches for QAPI unions, but as that touches a lot more client code, it is better as separate patches. But since unions and alternates share gen_variants(), I had to hack in a way to test if we are visiting an alternate type for setting the is_unboxed flag: look for a non-object branch. This works because alternates have at least two branches, with at most one object branch, while unions have only object branches. The hack will go away in a later patch. The generated code difference to qapi-types.h is relatively small: | struct BlockdevRef { | QType type; | union { /* union tag is @type */ | void *data; |- BlockdevOptions *definition; |+ BlockdevOptions definition; | char *reference; | } u; | }; The corresponding spot in qapi-visit.c calls visit_type_FOO(), which first calls visit_start_struct() to allocate or deallocate the member and handle a layer of {} from the JSON stream, then visits the members. To peel off the indirection and the memory management that comes with it, we inline this call, then suppress allocation / deallocation by passing NULL to visit_start_struct(), and adjust the member visit: | switch ((*obj)->type) { | case QTYPE_QDICT: |- visit_type_BlockdevOptions(v, name, &(*obj)->u.definition, &err); |+ visit_start_struct(v, name, NULL, 0, &err); |+ if (err) { |+ break; |+ } |+ visit_type_BlockdevOptions_fields(v, &(*obj)->u.definition, &err); |+ error_propagate(errp, err); |+ err = NULL; |+ visit_end_struct(v, &err); | break; | case QTYPE_QSTRING: | visit_type_str(v, name, &(*obj)->u.reference, &err); The visit of non-object fields is unchanged. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1455778109-6278-13-git-send-email-eblake@redhat.com> [Commit message tweaked] Signed-off-by: Markus Armbruster <armbru@redhat.com> |
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.. | ||
kvm | ||
qemu-guest-agent | ||
qemugdb | ||
qmp | ||
tracetool | ||
analyse-9p-simpletrace.py | ||
analyze-migration.py | ||
check-qerror.sh | ||
checkpatch.pl | ||
clean-includes | ||
cleanup-trace-events.pl | ||
cocci-macro-file.h | ||
coverity-model.c | ||
create_config | ||
disas-objdump.pl | ||
dump-guest-memory.py | ||
extract-vsssdk-headers | ||
feature_to_c.sh | ||
get_maintainer.pl | ||
gtester-cat | ||
hxtool | ||
make_device_config.sh | ||
make-release | ||
ordereddict.py | ||
qapi-commands.py | ||
qapi-event.py | ||
qapi-introspect.py | ||
qapi-types.py | ||
qapi-visit.py | ||
qapi.py | ||
qemu-binfmt-conf.sh | ||
qemu-gdb.py | ||
qtest.py | ||
refresh-pxe-roms.sh | ||
shaderinclude.pl | ||
signrom.py | ||
simpletrace.py | ||
switch-timer-api | ||
texi2pod.pl | ||
tracetool.py | ||
update-linux-headers.sh | ||
vmstate-static-checker.py |