trace: Do not include qom/cpu.h into generated trace.h

docs/devel/tracing.txt explains "since many source files include
trace.h, [the generated trace.h use] a minimum of types and other
header files included to keep the namespace clean and compile times
and dependencies down."

Commit 4815185902 "trace: Add per-vCPU tracing states for events with
the 'vcpu' property" made them all include qom/cpu.h via
control-internal.h.  qom/cpu.h in turn includes about thirty headers.
Ouch.

Per-vCPU tracing is currently not supported in sub-directories'
trace-events.  In other words, qom/cpu.h can only be used in
trace-root.h, not in any trace.h.

Split trace/control-vcpu.h off trace/control.h and
trace/control-internal.h.  Have the generated trace.h include
trace/control.h (which no longer includes qom/cpu.h), and trace-root.h
include trace/control-vcpu.h (which includes it).

The resulting improvement is a bit disappointing: in my "build
everything" tree, some 1100 out of 6600 objects (not counting tests
and objects that don't depend on qemu/osdep.h) depend on a trace.h,
and about 600 of them no longer depend on qom/cpu.h.  But more than
1300 others depend on trace-root.h.  More work is clearly needed.
Left for another day.

Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-8-armbru@redhat.com>

block/block-backend.c

@@ -15,6 +15,7 @@
 #include "block/block_int.h"
 #include "block/blockjob.h"
 #include "block/throttle-groups.h"
+#include "hw/qdev-core.h"
 #include "sysemu/blockdev.h"
 #include "sysemu/sysemu.h"
 #include "qapi/error.h"

qom/object.c

@@ -11,6 +11,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "hw/qdev-core.h"
 #include "qapi/error.h"
 #include "qom/object.h"
 #include "qom/object_interfaces.h"

scripts/tracetool/format/c.py

@@ -28,6 +28,7 @@ def generate(events, backend, group):
     out('/* This file is autogenerated by tracetool, do not edit. */',
         '',
         '#include "qemu/osdep.h"',
+        '#include "qemu/module.h"',
         '#include "%s"' % header,
         '')
 

scripts/tracetool/format/h.py

@@ -17,12 +17,17 @@ from tracetool import out
 
 
 def generate(events, backend, group):
+    if group == "root":
+        header = "trace/control-vcpu.h"
+    else:
+        header = "trace/control.h"
+
     out('/* This file is autogenerated by tracetool, do not edit. */',
         '',
         '#ifndef TRACE_%s_GENERATED_TRACERS_H' % group.upper(),
         '#define TRACE_%s_GENERATED_TRACERS_H' % group.upper(),
         '',
-        '#include "trace/control.h"',
+        '#include "%s"' % header,
         '')
 
     for e in events:

trace/control-internal.h

@@ -10,9 +10,6 @@
 #ifndef TRACE__CONTROL_INTERNAL_H
 #define TRACE__CONTROL_INTERNAL_H
 
-#include "qom/cpu.h"
-
-
 extern int trace_events_enabled_count;
 
 
@@ -59,28 +56,6 @@ static inline bool trace_event_get_state_dynamic(TraceEvent *ev)
     return unlikely(trace_events_enabled_count) && *ev->dstate;
 }
 
-static inline bool
-trace_event_get_vcpu_state_dynamic_by_vcpu_id(CPUState *vcpu,
-                                              uint32_t vcpu_id)
-{
-    /* it's on fast path, avoid consistency checks (asserts) */
-    if (unlikely(trace_events_enabled_count)) {
-        return test_bit(vcpu_id, vcpu->trace_dstate);
-    } else {
-        return false;
-    }
-}
-
-static inline bool trace_event_get_vcpu_state_dynamic(CPUState *vcpu,
-                                                      TraceEvent *ev)
-{
-    uint32_t vcpu_id;
-    assert(trace_event_is_vcpu(ev));
-    vcpu_id = trace_event_get_vcpu_id(ev);
-    return trace_event_get_vcpu_state_dynamic_by_vcpu_id(vcpu, vcpu_id);
-}
-
-
 void trace_event_register_group(TraceEvent **events);
 
 #endif /* TRACE__CONTROL_INTERNAL_H */

trace/control-vcpu.h

@@ -0,0 +1,63 @@
+/*
+ * Interface for configuring and controlling the state of tracing events.
+ *
+ * Copyright (C) 2011-2016 Lluís Vilanova <vilanova@ac.upc.edu>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef TRACE__CONTROL_VCPU_H
+#define TRACE__CONTROL_VCPU_H
+
+#include "control.h"
+#include "event-internal.h"
+#include "qom/cpu.h"
+
+/**
+ * trace_event_get_vcpu_state:
+ * @vcpu: Target vCPU.
+ * @id: Event identifier name.
+ *
+ * Get the tracing state of an event (both static and dynamic) for the given
+ * vCPU.
+ *
+ * If the event has the disabled property, the check will have no performance
+ * impact.
+ */
+#define trace_event_get_vcpu_state(vcpu, id)                            \
+    ((id ##_ENABLED) &&                                                 \
+     trace_event_get_vcpu_state_dynamic_by_vcpu_id(                     \
+         vcpu, _ ## id ## _EVENT.vcpu_id))
+
+/**
+ * trace_event_get_vcpu_state_dynamic:
+ *
+ * Get the dynamic tracing state of an event for the given vCPU.
+ */
+static bool trace_event_get_vcpu_state_dynamic(CPUState *vcpu, TraceEvent *ev);
+
+#include "control-internal.h"
+
+static inline bool
+trace_event_get_vcpu_state_dynamic_by_vcpu_id(CPUState *vcpu,
+                                              uint32_t vcpu_id)
+{
+    /* it's on fast path, avoid consistency checks (asserts) */
+    if (unlikely(trace_events_enabled_count)) {
+        return test_bit(vcpu_id, vcpu->trace_dstate);
+    } else {
+        return false;
+    }
+}
+
+static inline bool trace_event_get_vcpu_state_dynamic(CPUState *vcpu,
+                                                      TraceEvent *ev)
+{
+    uint32_t vcpu_id;
+    assert(trace_event_is_vcpu(ev));
+    vcpu_id = trace_event_get_vcpu_id(ev);
+    return trace_event_get_vcpu_state_dynamic_by_vcpu_id(vcpu, vcpu_id);
+}
+
+#endif

trace/control.h

@@ -119,22 +119,6 @@ static const char * trace_event_get_name(TraceEvent *ev);
 #define trace_event_get_state_backends(id)              \
     ((id ##_ENABLED) && id ##_BACKEND_DSTATE())
 
-/**
- * trace_event_get_vcpu_state:
- * @vcpu: Target vCPU.
- * @id: Event identifier name.
- *
- * Get the tracing state of an event (both static and dynamic) for the given
- * vCPU.
- *
- * If the event has the disabled property, the check will have no performance
- * impact.
- */
-#define trace_event_get_vcpu_state(vcpu, id)                            \
-    ((id ##_ENABLED) &&                                                 \
-     trace_event_get_vcpu_state_dynamic_by_vcpu_id(                     \
-         vcpu, _ ## id ## _EVENT.vcpu_id))
-
 /**
  * trace_event_get_state_static:
  * @id: Event identifier.
@@ -155,14 +139,6 @@ static bool trace_event_get_state_static(TraceEvent *ev);
  */
 static bool trace_event_get_state_dynamic(TraceEvent *ev);
 
-/**
- * trace_event_get_vcpu_state_dynamic:
- *
- * Get the dynamic tracing state of an event for the given vCPU.
- */
-static bool trace_event_get_vcpu_state_dynamic(CPUState *vcpu, TraceEvent *ev);
-
-
 /**
  * trace_event_set_state_dynamic:
  *

trace/qmp.c

@@ -10,7 +10,7 @@
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "qapi/qapi-commands-trace.h"
-#include "control.h"
+#include "control-vcpu.h"
 
 
 static CPUState *get_cpu(bool has_vcpu, int vcpu, Error **errp)

ui/vnc.c

@@ -28,6 +28,7 @@
 #include "vnc.h"
 #include "vnc-jobs.h"
 #include "trace.h"
+#include "hw/qdev-core.h"
 #include "sysemu/sysemu.h"
 #include "qemu/error-report.h"
 #include "qemu/module.h"