string-output-visitor: show structs as "<omitted>"

StringOutputVisitor crashes when it visits a struct because
->start_struct() is NULL.

Show "<omitted>" instead of crashing. This is necessary because the
virtio-blk-pci iothread-vq-mapping parameter that I'd like to introduce
soon is a list of IOThreadMapping structs.

This patch is a quick fix to solve the crash, but the long-term solution
is replacing StringOutputVisitor with something that can handle the full
gamut of values in QEMU.

Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20231212134934.500289-1-stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Stefan Hajnoczi 2023-12-12 08:49:34 -05:00 committed by Kevin Wolf
parent c12887e1b0
commit ff32bb5347
2 changed files with 19 additions and 3 deletions

View File

@ -26,9 +26,9 @@ typedef struct StringOutputVisitor StringOutputVisitor;
* If everything else succeeds, pass @result to visit_complete() to
* collect the result of the visit.
*
* The string output visitor does not implement support for visiting
* QAPI structs, alternates, null, or arbitrary QTypes. It also
* requires a non-null list argument to visit_start_list().
* The string output visitor does not implement support for alternates, null,
* or arbitrary QTypes. Struct fields are not shown. It also requires a
* non-null list argument to visit_start_list().
*/
Visitor *string_output_visitor_new(bool human, char **result);

View File

@ -292,6 +292,20 @@ static bool print_type_null(Visitor *v, const char *name, QNull **obj,
return true;
}
static bool start_struct(Visitor *v, const char *name, void **obj,
size_t size, Error **errp)
{
return true;
}
static void end_struct(Visitor *v, void **obj)
{
StringOutputVisitor *sov = to_sov(v);
/* TODO actually print struct fields */
string_output_set(sov, g_strdup("<omitted>"));
}
static bool
start_list(Visitor *v, const char *name, GenericList **list, size_t size,
Error **errp)
@ -379,6 +393,8 @@ Visitor *string_output_visitor_new(bool human, char **result)
v->visitor.type_str = print_type_str;
v->visitor.type_number = print_type_number;
v->visitor.type_null = print_type_null;
v->visitor.start_struct = start_struct;
v->visitor.end_struct = end_struct;
v->visitor.start_list = start_list;
v->visitor.next_list = next_list;
v->visitor.end_list = end_list;