trace: split trace_init_events out of trace_init_backends

This is cleaner and has two advantages.  First, it improves error
reporting with -daemonize.  Second, multiple "-trace events" options
now cumulate.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-id: 1452174932-28657-3-git-send-email-den@openvz.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

4 files changed, 19 insertions, 11 deletions

diff --git a/qemu-io.c b/qemu-io.c
index d593f19642..1c11d5711e 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -435,7 +435,7 @@ int main(int argc, char **argv)
             }
             break;
         case 'T':
-            if (!trace_init_backends(optarg, NULL)) {
+            if (!trace_init_backends(optarg)) {
                 exit(1); /* error message will have been printed */
             }
             break;
diff --git a/trace/control.c b/trace/control.c
index 700440c5ae..931d64c0c8 100644
--- a/trace/control.c
+++ b/trace/control.c
@@ -88,7 +88,7 @@ TraceEvent *trace_event_pattern(const char *pat, TraceEvent *ev)
     return NULL;
 }
 
-static void trace_init_events(const char *fname)
+void trace_init_events(const char *fname)
 {
     Location loc;
     FILE *fp;
@@ -145,7 +145,7 @@ static void trace_init_events(const char *fname)
     loc_pop(&loc);
 }
 
-bool trace_init_backends(const char *events, const char *file)
+bool trace_init_backends(const char *file)
 {
 #ifdef CONFIG_TRACE_SIMPLE
     if (!st_init(file)) {
@@ -167,6 +167,5 @@ bool trace_init_backends(const char *events, const char *file)
     }
 #endif
 
-    trace_init_events(events);
     return true;
 }
diff --git a/trace/control.h b/trace/control.h
index 6af7ddc628..7905917213 100644
--- a/trace/control.h
+++ b/trace/control.h
@@ -150,8 +150,6 @@ static void trace_event_set_state_dynamic(TraceEvent *ev, bool state);
 
 /**
  * trace_init_backends:
- * @events: Name of file with events to be enabled at startup; may be NULL.
- *          Corresponds to commandline option "-trace events=...".
  * @file:   Name of trace output file; may be NULL.
  *          Corresponds to commandline option "-trace file=...".
  *
@@ -159,7 +157,18 @@ static void trace_event_set_state_dynamic(TraceEvent *ev, bool state);
  *
  * Returns: Whether the backends could be successfully initialized.
  */
-bool trace_init_backends(const char *events, const char *file);
+bool trace_init_backends(const char *file);
+
+/**
+ * trace_init_events:
+ * @events: Name of file with events to be enabled at startup; may be NULL.
+ *          Corresponds to commandline option "-trace events=...".
+ *
+ * Read the list of enabled tracing events.
+ *
+ * Returns: Whether the backends could be successfully initialized.
+ */
+void trace_init_events(const char *file);
 
 
 #include "trace/control-internal.h"
diff --git a/vl.c b/vl.c
index f043009f67..ff2a7d5aed 100644
--- a/vl.c
+++ b/vl.c
@@ -2988,7 +2988,6 @@ int main(int argc, char **argv, char **envp)
     bool userconfig = true;
     const char *log_mask = NULL;
     const char *log_file = NULL;
-    const char *trace_events = NULL;
     const char *trace_file = NULL;
     ram_addr_t maxram_size;
     uint64_t ram_slots = 0;
@@ -3905,8 +3904,9 @@ int main(int argc, char **argv, char **envp)
                 if (!opts) {
                     exit(1);
                 }
-                trace_events = qemu_opt_get(opts, "events");
+                trace_init_events(qemu_opt_get(opts, "events"));
                 trace_file = qemu_opt_get(opts, "file");
+                qemu_opts_del(opts);
                 break;
             }
             case QEMU_OPTION_readconfig:
@@ -4106,7 +4106,7 @@ int main(int argc, char **argv, char **envp)
     }
 
     if (!is_daemonized()) {
-        if (!trace_init_backends(trace_events, trace_file)) {
+        if (!trace_init_backends(trace_file)) {
             exit(1);
         }
     }
@@ -4653,7 +4653,7 @@ int main(int argc, char **argv, char **envp)
     os_setup_post();
 
     if (is_daemonized()) {
-        if (!trace_init_backends(trace_events, trace_file)) {
+        if (!trace_init_backends(trace_file)) {
             exit(1);
         }
     }