[Spice-devel] [PATCH spice-server 1/2] Fix compile warnings on Linux 32bit system

[Frediano Ziglio]

Based on a patch from Hongzhi.Song <hongzhi.song at windriver.com>.

There are following compile errors on Linux 32bit system with -Werror
for gcc.

red-channel.c:207:73: error: format '%x' expects argument of type
'unsigned int', but argument 7 has type 'long unsigned int' [-Werror=format=]
|207| red_channel_debug(self, "thread_id 0x%" G_GSIZE_MODIFIER "x",
				~~~~~~~~~~~~~~~~~~~~~^
			self->priv->thread_id);
		~~~~~~~~~~~~~~~~~~~~~^

pthread_t is an opaque type so there it's not easy to get portably
the printf format string. However the type must be comparable in C
so this (excluding floating point which does not make sense) means
an integral type or a pointer.
Under *BSD this is a pointer so can be converted without loosing
precision to void*.
Under Linux this is a "unsigned long int" type, being Linux LP32 or
LP64 this means that the size of pthread_t is the same as size_t
so can be converted without loosing precision to void*.
Under MingW (the pthread port to Windows) this is a uintptr_t type
that is can be converted without loosing precision to void*.
On any potential future platforms if the integral type is smaller
than a uintptr_t type (which has the same size of void*) the cast
should trigger a warning and if not won't loose precision; the
integral type is unlikely to be bigger than a pointer and likely
the cast would trigger a warning.

The cast on read_binary (red-replay-qxl.c) is safe, "*size" is a
size_t while "strm.total_out" is the number of written bytes in
a buffer which cannot be bigger than a size_t.

Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
---
 server/red-channel.c    |  8 ++++----
 server/red-client.c     | 14 +++++++-------
 server/red-replay-qxl.c |  2 +-
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/server/red-channel.c b/server/red-channel.c
index 82e522395..e09edacf8 100644
--- a/server/red-channel.c
+++ b/server/red-channel.c
@@ -202,7 +202,7 @@ red_channel_constructed(GObject *object)
 {
     RedChannel *self = RED_CHANNEL(object);
 
-    red_channel_debug(self, "thread_id 0x%" G_GSIZE_MODIFIER "x", self->priv->thread_id);
+    red_channel_debug(self, "thread_id %p", (void*) self->priv->thread_id);
 
     RedChannelClass *klass = RED_CHANNEL_GET_CLASS(self);
 
@@ -473,11 +473,11 @@ void red_channel_remove_client(RedChannel *channel, RedChannelClient *rcc)
 
     if (!pthread_equal(pthread_self(), channel->priv->thread_id)) {
         red_channel_warning(channel,
-                            "channel->thread_id (0x%" G_GSIZE_MODIFIER "x) != "
-                            "pthread_self (0x%" G_GSIZE_MODIFIER "x)."
+                            "channel->thread_id (%p) != "
+                            "pthread_self (%p)."
                             "If one of the threads is != io-thread && != vcpu-thread, "
                             "this might be a BUG",
-                            channel->priv->thread_id, pthread_self());
+                            (void*) channel->priv->thread_id, (void*) pthread_self());
     }
     spice_return_if_fail(channel);
     link = g_list_find(channel->priv->clients, rcc);
diff --git a/server/red-client.c b/server/red-client.c
index 961b4970e..a4c79a174 100644
--- a/server/red-client.c
+++ b/server/red-client.c
@@ -174,11 +174,11 @@ void red_client_migrate(RedClient *client)
     RedChannel *channel;
 
     if (!pthread_equal(pthread_self(), client->thread_id)) {
-        spice_warning("client->thread_id (0x%" G_GSIZE_MODIFIER "x) != "
-                      "pthread_self (0x%" G_GSIZE_MODIFIER "x)."
+        spice_warning("client->thread_id (%p) != "
+                      "pthread_self (%p)."
                       "If one of the threads is != io-thread && != vcpu-thread,"
                       " this might be a BUG",
-                      client->thread_id, pthread_self());
+                      (void*) client->thread_id, (void*) pthread_self());
     }
     FOREACH_CHANNEL_CLIENT(client, rcc) {
         if (red_channel_client_is_connected(rcc)) {
@@ -193,12 +193,12 @@ void red_client_destroy(RedClient *client)
     RedChannelClient *rcc;
 
     if (!pthread_equal(pthread_self(), client->thread_id)) {
-        spice_warning("client->thread_id (0x%" G_GSIZE_MODIFIER "x) != "
-                      "pthread_self (0x%" G_GSIZE_MODIFIER "x)."
+        spice_warning("client->thread_id (%p) != "
+                      "pthread_self (%p)."
                       "If one of the threads is != io-thread && != vcpu-thread,"
                       " this might be a BUG",
-                      client->thread_id,
-                      pthread_self());
+                      (void*) client->thread_id,
+                      (void*) pthread_self());
     }
     red_client_set_disconnecting(client);
     FOREACH_CHANNEL_CLIENT(client, rcc) {
diff --git a/server/red-replay-qxl.c b/server/red-replay-qxl.c
index 6d3481805..fa44fa7c4 100644
--- a/server/red-replay-qxl.c
+++ b/server/red-replay-qxl.c
@@ -265,7 +265,7 @@ static replay_t read_binary(SpiceReplay *replay, const char *prefix, size_t *siz
         }
         if ((ret = inflate(&strm, Z_NO_FLUSH)) != Z_STREAM_END) {
             spice_error("inflate error %d (disc: %" G_GSSIZE_FORMAT ")",
-                        ret, *size - strm.total_out);
+                        ret, (size_t) (*size - strm.total_out));
             if (ret == Z_DATA_ERROR) {
                 /* last operation may be wrong. since we do the recording
                  * in red_worker, when there is a shutdown from the vcpu/io thread
-- 
2.20.1