dfaggioli/qemu
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

qapi: Add parameter to visit_end_*

Browse Source 
Rather than making the dealloc visitor track of stack of pointers
remembered during visit_start_* in order to free them during
visit_end_*, it's a lot easier to just make all callers pass the
same pointer to visit_end_*.  The generated code has access to the
same pointer, while all other users are doing virtual walks and
can pass NULL.  The dealloc visitor is then greatly simplified.

All three visit_end_*() functions intentionally take a void**,
even though the visit_start_*() functions differ between void**,
GenericList**, and GenericAlternate**.  This is done for several
reasons: when doing a virtual walk, passing NULL doesn't care
what the type is, but when doing a generated walk, we already
have to cast the caller's specific FOO* to call visit_start,
while using void** lets us use visit_end without a cast. Also,
an upcoming patch will add a clone visitor that wants to use
the same implementation for all three visit_end callbacks,
which is made easier if all three share the same signature.

For visitors with already track per-object state (the QMP visitors
via a stack, and the string visitors which do not allow nesting),
add an assertion that the caller is indeed passing the same
pointer to paired calls.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-4-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
This commit is contained in:
Eric Blake
2016-06-09 10:48:34 -06:00
committed by Markus Armbruster
parent 911ee36d41
commit 1158bb2a05
20 changed files with 86 additions and 105 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
include/qapi/visitor-impl.h
View File

@@ -47,7 +47,7 @@ struct Visitor
void (*check_struct)(Visitor *v, Error **errp);
/* Must be set to visit structs */
void (*end_struct)(Visitor *v);
void (*end_struct)(Visitor *v, void **obj);
/* Must be set; implementations may require @list to be non-null,
* but must document it. */
@@ -58,7 +58,7 @@ struct Visitor
GenericList *(*next_list)(Visitor *v, GenericList *tail, size_t size);
/* Must be set */
void (*end_list)(Visitor *v);
void (*end_list)(Visitor *v, void **list);
/* Must be set by input and dealloc visitors to visit alternates;
* optional for output visitors. */
@@ -67,7 +67,7 @@ struct Visitor
bool promote_int, Error **errp);
/* Optional, needed for dealloc visitor */
void (*end_alternate)(Visitor *v);
void (*end_alternate)(Visitor *v, void **obj);
/* Must be set */
void (*type_int64)(Visitor *v, const char *name, int64_t *obj,