trace: remove the TraceEventID and TraceEventVCPUID enums

The TraceEventID and TraceEventVCPUID enums constants are
no longer actually used for anything critical.

The TRACE_EVENT_COUNT limit is used to determine the size
of the TraceEvents array, and can be removed if we just
NULL terminate the array instead.

The TRACE_VCPU_EVENT_COUNT limit is used as a magic value
for marking non-vCPU events, and also for declaring the
size of the trace dstate mask in the CPUState struct.
The former usage can be replaced by a dedicated constant
TRACE_EVENT_VCPU_NONE, defined as (uint32_t)-1. For the
latter usage, we can simply define a constant for the
number of VCPUs, avoiding the need for the full enum.

The only other usages of the enum values can be replaced
by accesing the id/vcpu_id fields via the named TraceEvent
structs.

Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-11-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 11 insertions, 5 deletions

diff --git a/scripts/tracetool/format/events_c.py b/scripts/tracetool/format/events_c.py
index a97054fd58..40ae39568e 100644
--- a/scripts/tracetool/format/events_c.py
+++ b/scripts/tracetool/format/events_c.py
@@ -28,11 +28,16 @@ def generate(events, backend):
     for e in events:
         out('uint16_t %s;' % e.api(e.QEMU_DSTATE))
 
+    next_id = 0
+    next_vcpu_id = 0
     for e in events:
+        id = next_id
+        next_id += 1
         if "vcpu" in e.properties:
-            vcpu_id = "TRACE_VCPU_" + e.name.upper()
+            vcpu_id = next_vcpu_id
+            next_vcpu_id += 1
         else:
-            vcpu_id = "TRACE_VCPU_EVENT_COUNT"
+            vcpu_id = "TRACE_VCPU_EVENT_NONE"
         out('TraceEvent %(event)s = {',
             '    .id = %(id)s,',
             '    .vcpu_id = %(vcpu_id)s,',
@@ -41,16 +46,17 @@ def generate(events, backend):
             '    .dstate = &%(dstate)s ',
             '};',
             event = e.api(e.QEMU_EVENT),
-            id = "TRACE_" + e.name.upper(),
+            id = id,
             vcpu_id = vcpu_id,
             name = e.name,
             sstate = "TRACE_%s_ENABLED" % e.name.upper(),
             dstate = e.api(e.QEMU_DSTATE))
 
-    out('TraceEvent *trace_events[TRACE_EVENT_COUNT] = {')
+    out('TraceEvent *trace_events[] = {')
 
     for e in events:
         out('    &%(event)s,', event = e.api(e.QEMU_EVENT))
 
-    out('};',
+    out('  NULL,',
+        '};',
         '')