[libvirt] [RFC PATCH 3/8] util: Generate a common internal only error print

[John Ferlan]

If virObjectIsClass fails "internally" to virobject.c, create a macro to
generate the VIR_WARN describing what the problem is. Also improve the
checks and message a bit to indicate which was the failure - whether the
obj was NULL or just not the right class

Signed-off-by: John Ferlan <jferlan at redhat.com>
---
 src/util/virobject.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/util/virobject.c b/src/util/virobject.c
index 5d5b6a3..9fe4e71 100644
--- a/src/util/virobject.c
+++ b/src/util/virobject.c
@@ -47,6 +47,16 @@ struct _virClass {
     virObjectDisposeCallback dispose;
 };
 
+#define VIR_OBJECT_USAGE_PRINT_WARNING(anyobj, objclass)                    \
+    do {                                                                    \
+        virObjectPtr obj = anyobj;                                          \
+        if (!obj)                                                           \
+            VIR_WARN("Object %p is not a virObject class instance", anyobj);\
+        else                                                                \
+            VIR_WARN("Object %p (%s) is not a %s instance",                 \
+                      anyobj, obj->klass->name, #objclass);                 \
+    } while (0)
+
 static virClassPtr virObjectClass;
 static virClassPtr virObjectLockableClass;
 
@@ -312,14 +322,10 @@ virObjectRef(void *anyobj)
 static virObjectLockablePtr
 virObjectGetLockableObj(void *anyobj)
 {
-    virObjectPtr obj;
-
     if (virObjectIsClass(anyobj, virObjectLockableClass))
         return anyobj;
 
-    obj = anyobj;
-    VIR_WARN("Object %p (%s) is not a virObjectLockable instance",
-              anyobj, obj ? obj->klass->name : "(unknown)");
+    VIR_OBJECT_USAGE_PRINT_WARNING(anyobj, virObjectLockableClass);
 
     return NULL;
 
-- 
2.9.3