trace: separate trace event control and query routines from the simple backend

Generalize the 'st_print_trace_events' and 'st_change_trace_event_state' into
backend-specific 'trace_print_events' and 'trace_event_set_state' (respectively)
in the "trace/control.h" file.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>

4 files changed, 33 insertions, 11 deletions

diff --git a/trace/control.h b/trace/control.h
index bb54339..c99b4d5 100644
--- a/trace/control.h
+++ b/trace/control.h
@@ -10,7 +10,16 @@
 #ifndef TRACE_CONTROL_H
 #define TRACE_CONTROL_H
 
-#include <stdbool.h>
+#include "qemu-common.h"
+
+
+/** Print the state of all events. */
+void trace_print_events(FILE *stream, fprintf_function stream_printf);
+/** Set the state of an event.
+ *
+ * @return Whether the state changed.
+ */
+bool trace_event_set_state(const char *name, bool state);
 
 
 /** Initialize the tracing backend.
diff --git a/trace/default.c b/trace/default.c
index 42fdb6b..3573d5b 100644
--- a/trace/default.c
+++ b/trace/default.c
@@ -10,6 +10,21 @@
 #include "trace/control.h"
 
 
+void trace_print_events(FILE *stream, fprintf_function stream_printf)
+{
+    fprintf(stderr, "warning: "
+            "cannot print the trace events with the current backend\n");
+    stream_printf(stream, "error: "
+                  "operation not supported with the current backend\n");
+}
+
+bool trace_event_set_state(const char *name, bool state)
+{
+    fprintf(stderr, "warning: "
+            "cannot set the state of a trace event with the current backend\n");
+    return false;
+}
+
 bool trace_backend_init(const char *file)
 {
     if (file) {
diff --git a/trace/simple.c b/trace/simple.c
index 369e860..70689e9 100644
--- a/trace/simple.c
+++ b/trace/simple.c
@@ -303,7 +303,12 @@ void st_print_trace(FILE *stream, int (*stream_printf)(FILE *stream, const char
     }
 }
 
-void st_print_trace_events(FILE *stream, int (*stream_printf)(FILE *stream, const char *fmt, ...))
+void st_flush_trace_buffer(void)
+{
+    flush_trace_file(true);
+}
+
+void trace_print_events(FILE *stream, fprintf_function stream_printf)
 {
     unsigned int i;
 
@@ -313,24 +318,19 @@ void st_print_trace_events(FILE *stream, int (*stream_printf)(FILE *stream, cons
     }
 }
 
-bool st_change_trace_event_state(const char *name, bool enabled)
+bool trace_event_set_state(const char *name, bool state)
 {
     unsigned int i;
 
     for (i = 0; i < NR_TRACE_EVENTS; i++) {
         if (!strcmp(trace_list[i].tp_name, name)) {
-            trace_list[i].state = enabled;
+            trace_list[i].state = state;
             return true;
         }
     }
     return false;
 }
 
-void st_flush_trace_buffer(void)
-{
-    flush_trace_file(true);
-}
-
 bool trace_backend_init(const char *file)
 {
     pthread_t thread;
diff --git a/trace/simple.h b/trace/simple.h
index 08b9a52..466e75b 100644
--- a/trace/simple.h
+++ b/trace/simple.h
@@ -30,8 +30,6 @@ void trace4(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, uint64_t
 void trace5(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, uint64_t x4, uint64_t x5);
 void trace6(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, uint64_t x4, uint64_t x5, uint64_t x6);
 void st_print_trace(FILE *stream, fprintf_function stream_printf);
-void st_print_trace_events(FILE *stream, fprintf_function stream_printf);
-bool st_change_trace_event_state(const char *tname, bool tstate);
 void st_print_trace_file_status(FILE *stream, fprintf_function stream_printf);
 void st_set_trace_file_enabled(bool enable);
 bool st_set_trace_file(const char *file);