qemu/include
Eric Blake 68ab47e4b4 qapi: Change visit_type_FOO() to no longer return partial objects
Returning a partial object on error is an invitation for a careless
caller to leak memory.  We already fixed things in an earlier
patch to guarantee NULL if visit_start fails ("qapi: Guarantee
NULL obj on input visitor callback error"), but that does not
help the case where visit_start succeeds but some other failure
happens before visit_end, such that we leak a partially constructed
object outside visit_type_FOO(). As no one outside the testsuite
was actually relying on these semantics, it is cleaner to just
document and guarantee that ALL pointer-based visit_type_FOO()
functions always leave a safe value in *obj during an input visitor
(either the new object on success, or NULL if an error is
encountered), so callers can now unconditionally use
qapi_free_FOO() to clean up regardless of whether an error occurred.

The decision is done by adding visit_is_input(), then updating the
generated code to check if additional cleanup is needed based on
the type of visitor in use.

Note that we still leave *obj unchanged after a scalar-based
visit_type_FOO(); I did not feel like auditing all uses of
visit_type_Enum() to see if the callers would tolerate a specific
sentinel value (not to mention having to decide whether it would
be better to use 0 or ENUM__MAX as that sentinel).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1461879932-9020-25-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:55 +02:00
..
block block: Fix bdrv_drain in coroutine 2016-04-11 16:59:09 +01:00
crypto include/crypto: Include qapi-types.h or qemu/bswap.h instead of qemu-common.h 2016-03-22 22:20:16 +01:00
disas disas: Add print_insn to disassemble info 2015-07-09 15:20:40 +02:00
exec qemu-log: dfilter-ise exec, out_asm, op and opt_op 2016-03-22 22:20:18 +01:00
fpu include: Clean up includes 2016-02-23 12:43:05 +00:00
hw virtio-input: support absolute axis config in pass-through 2016-04-13 17:26:12 +02:00
io io: implement socket watch for win32 using WSAEventSelect+select 2016-03-10 17:19:07 +00:00
libdecnumber include: Clean up includes 2016-02-23 12:43:05 +00:00
migration migration (ordinary): move bdrv_invalidate_cache_all of of coroutine context 2016-02-26 20:39:50 +05:30
monitor Use scripts/clean-includes to drop redundant qemu/typedefs.h 2016-03-22 22:20:16 +01:00
net Use scripts/clean-includes to drop redundant qemu/typedefs.h 2016-03-22 22:20:16 +01:00
qapi qapi: Change visit_type_FOO() to no longer return partial objects 2016-05-12 09:47:55 +02:00
qemu event-notifier: Add "is_external" parameter 2016-04-22 16:43:56 +02:00
qom qom: -object error messages lost location, restore it 2016-04-28 08:19:36 +02:00
standard-headers update Linux headers to 4.6 2016-04-05 11:46:52 +02:00
sysemu kvm: add kvm_device_supported() helper function 2016-03-30 17:27:24 +01:00
ui ui/virtio-gpu: add and use qemu_create_displaysurface_pixman 2016-04-11 12:32:01 +02:00
elf.h include: Clean up includes 2016-02-23 12:43:05 +00:00
glib-compat.h glib: add compatibility interface for g_hash_table_add() 2015-10-30 09:01:03 +01:00
qemu-common.h util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00
qemu-io.h qemu-io: Use BlockBackend 2015-02-16 15:07:19 +00:00
qjson.h QJSON: Add JSON writer 2015-02-05 17:16:14 +01:00
trace-tcg.h trace: [tcg] Generate TCG tracing routines 2014-08-12 14:26:12 +01:00
trace.h trace: [tcg] Include event definitions in "trace.h" 2014-08-12 14:26:12 +01:00