Eric Blake 2f42c2c195 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). Backports commit 68ab47e4b4ecc1c4649362b8cc1e49794d1a6537 from qemu		2018-02-23 19:53:17 -05:00
..
create_config	more cleanup qemu/configure	2017-01-19 14:11:54 +08:00
make_device_config.sh	fix file perms	2015-08-28 21:05:38 -07:00
ordereddict.py	import	2015-08-21 15:04:50 +08:00
qapi-event.py	qapi: Split visit_end_struct() into pieces	2018-02-23 19:13:47 -05:00
qapi-types.py	qapi: Adjust layout of FooList types	2018-02-23 14:49:06 -05:00
qapi-visit.py	qapi: Change visit_type_FOO() to no longer return partial objects	2018-02-23 19:53:17 -05:00
qapi.py	qapi: Use anonymous bases in QMP flat unions	2018-02-21 22:55:12 -05:00