[Spice-devel] [PATCH 01/11] FIXME hardcoded 58?

[Frediano Ziglio]

> 
> On Thu, 2015-10-29 at 07:24 -0400, Frediano Ziglio wrote:
> > > 
> > > From: Marc-André Lureau <marcandre.lureau at gmail.com>
> > > 
> > > ---
> > >  server/red_worker.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/server/red_worker.c b/server/red_worker.c
> > > index c027fde..3aa05d8 100644
> > > --- a/server/red_worker.c
> > > +++ b/server/red_worker.c
> > > @@ -9802,7 +9802,7 @@ static void
> > > guest_set_client_capabilities(RedWorker
> > > *worker)
> > >      DisplayChannelClient *dcc;
> > >      RedChannelClient *rcc;
> > >      RingItem *link, *next;
> > > -    uint8_t caps[58] = { 0 };
> > > +    uint8_t caps[58] = { 0 }; /* FIXME: 58?? */
> > >      int caps_available[] = {
> > >          SPICE_DISPLAY_CAP_SIZED_STREAM,
> > >          SPICE_DISPLAY_CAP_MONITORS_CONFIG,
> > > --
> > > 2.4.3
> > > 
> > 
> > I think the reply came from http://cgit.freedesktop.org/spice/spice-p
> > rotocol/commit/?id=361fd166b26b4450617b1f7175be9aaa7d8f6a7e
> > The "fix" would require a change (a definition) in spice-protocol
> > spice/qxl_dev.h file and use the mnemonic instead.
> 
> I guess the spice-protocol structure definition is the root cause of
> this number, but the direct reason that we're allocating this size
> array here is probably because of the definition of
> QxlInterface::set_client_capabilities() in server/spice-qxl.h. There is
> also a "magic" 58 in that function declaration. So if we're going to
> address the one in red_worker.c, we should probably address them both.
> 
> > 
> > Or we could use instead a sizeof(((QXLRom*)0)->client_capabilities).
> > 
> > Personally I would prefer the second, we just released a spice
> > -protocol release so doing the change,
> > bumping version and update version on spice-server is quite long.
> 
> 
> This seems OK to me.
> 
> Another option is to do both as an transitional measure. For example,
> introduce a SPICE_CAPABILITIES_SIZE #define in spice-protocol, and then
> in spice server do something like
> 
> #ifndef SPICE_CAPABILITIES_SIZE
>  #define SPICE_CAPABILITIES_SIZE sizeof(...)
> #endif
> 
> But I'm not sure it's worth the effort.
> 

I think this patch can go

[PATCH] worker: avoid to use constant directly for capability size

---
 server/red_worker.c | 2 +-
 server/spice-qxl.h  | 6 +++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/server/red_worker.c b/server/red_worker.c
index 96c0f14..2b23ffd 100644
--- a/server/red_worker.c
+++ b/server/red_worker.c
@@ -9802,7 +9802,7 @@ static void guest_set_client_capabilities(RedWorker *worker)
     DisplayChannelClient *dcc;
     RedChannelClient *rcc;
     RingItem *link, *next;
-    uint8_t caps[58] = { 0 };
+    uint8_t caps[SPICE_CAPABILITIES_SIZE] = { 0 };
     int caps_available[] = {
         SPICE_DISPLAY_CAP_SIZED_STREAM,
         SPICE_DISPLAY_CAP_MONITORS_CONFIG,
diff --git a/server/spice-qxl.h b/server/spice-qxl.h
index dd49a86..e1f14e7 100644
--- a/server/spice-qxl.h
+++ b/server/spice-qxl.h
@@ -24,6 +24,10 @@
 
 #include "spice-core.h"
 
+#ifndef SPICE_CAPABILITIES_SIZE
+#define SPICE_CAPABILITIES_SIZE (sizeof(((QXLRom*)0)->client_capabilities))
+#endif
+
 /* qxl interface */
 
 #define SPICE_INTERFACE_QXL "qxl"
@@ -175,7 +179,7 @@ struct QXLInterface {
                                  uint32_t num_updated_rects);
     void (*set_client_capabilities)(QXLInstance *qin,
                                     uint8_t client_present,
-                                    uint8_t caps[58]);
+                                    uint8_t caps[SPICE_CAPABILITIES_SIZE]);
     /* returns 1 if the interface is supported, 0 otherwise.
      * if monitors_config is NULL nothing is done except reporting the
      * return code. */
-- 
2.4.3