| Message ID | 20231212134934.500289-1-stefanha@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] string-output-visitor: show structs as "<omitted>" | expand |
Stefan Hajnoczi <stefanha@redhat.com> writes: > 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> Okay as a stopgap to unblock your virtio-blk-pci work. Suggest you merge this patch together with the patch that needs it. Reviewed-by: Markus Armbruster <armbru@redhat.com>
On Tue, 19 Dec 2023 at 09:49, Markus Armbruster <armbru@redhat.com> wrote: > > Stefan Hajnoczi <stefanha@redhat.com> writes: > > > 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> > > Okay as a stopgap to unblock your virtio-blk-pci work. Suggest you > merge this patch together with the patch that needs it. Thanks! Stefan
diff --git a/include/qapi/string-output-visitor.h b/include/qapi/string-output-visitor.h index 268dfe9986..b1ee473b30 100644 --- a/include/qapi/string-output-visitor.h +++ b/include/qapi/string-output-visitor.h @@ -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); diff --git a/qapi/string-output-visitor.c b/qapi/string-output-visitor.c index c0cb72dbe4..f0c1dea89e 100644 --- a/qapi/string-output-visitor.c +++ b/qapi/string-output-visitor.c @@ -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;
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> --- v2: - Note that struct fields are omitted in string-output-visitor.h [Markus] - Add a TODO comment in end_struct() [Markus] --- include/qapi/string-output-visitor.h | 6 +++--- qapi/string-output-visitor.c | 16 ++++++++++++++++ 2 files changed, 19 insertions(+), 3 deletions(-)