trace: move qemu_trace_opts to trace/control.c

The patch also creates trace_opt_parse() helper in trace/control.c to reuse
this code in next patches for qemu-nbd and qemu-io.

The patch also makes trace_init_events() static, as this call is not used
outside the module anymore.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1466174654-30130-4-git-send-email-den@openvz.org
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

trace/control.c

@@ -21,11 +21,33 @@
 #endif
 #include "qapi/error.h"
 #include "qemu/error-report.h"
+#include "qemu/config-file.h"
 #include "monitor/monitor.h"
 
 int trace_events_enabled_count;
 bool trace_events_dstate[TRACE_EVENT_COUNT];
 
+QemuOptsList qemu_trace_opts = {
+    .name = "trace",
+    .implied_opt_name = "enable",
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_trace_opts.head),
+    .desc = {
+        {
+            .name = "enable",
+            .type = QEMU_OPT_STRING,
+        },
+        {
+            .name = "events",
+            .type = QEMU_OPT_STRING,
+        },{
+            .name = "file",
+            .type = QEMU_OPT_STRING,
+        },
+        { /* end of list */ }
+    },
+};
+
+
 TraceEvent *trace_event_name(const char *name)
 {
     assert(name != NULL);
@@ -142,7 +164,7 @@ void trace_enable_events(const char *line_buf)
     }
 }
 
-void trace_init_events(const char *fname)
+static void trace_init_events(const char *fname)
 {
     Location loc;
     FILE *fp;
@@ -217,3 +239,21 @@ bool trace_init_backends(void)
 
     return true;
 }
+
+char *trace_opt_parse(const char *optarg)
+{
+    char *trace_file;
+    QemuOpts *opts = qemu_opts_parse_noisily(qemu_find_opts("trace"),
+                                             optarg, true);
+    if (!opts) {
+        exit(1);
+    }
+    if (qemu_opt_get(opts, "enable")) {
+        trace_enable_events(qemu_opt_get(opts, "enable"));
+    }
+    trace_init_events(qemu_opt_get(opts, "events"));
+    trace_file = g_strdup(qemu_opt_get(opts, "file"));
+    qemu_opts_del(opts);
+
+    return trace_file;
+}

trace/control.h

@@ -159,17 +159,6 @@ static void trace_event_set_state_dynamic(TraceEvent *ev, bool state);
  */
 bool trace_init_backends(void);
 
-/**
- * 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);
-
 /**
  * trace_init_file:
  * @file:   Name of trace output file; may be NULL.
@@ -197,6 +186,20 @@ void trace_list_events(void);
  */
 void trace_enable_events(const char *line_buf);
 
+/**
+ * Definition of QEMU options describing trace subsystem configuration
+ */
+extern QemuOptsList qemu_trace_opts;
+
+/**
+ * trace_opt_parse:
+ * @optarg: A string argument of --trace command line argument
+ *
+ * Initialize tracing subsystem.
+ *
+ * Returns the filename to save trace to.  It must be freed with g_free().
+ */
+char *trace_opt_parse(const char *optarg);
 
 #include "trace/control-internal.h"
 

vl.c

@@ -262,26 +262,6 @@ static QemuOptsList qemu_sandbox_opts = {
     },
 };
 
-static QemuOptsList qemu_trace_opts = {
-    .name = "trace",
-    .implied_opt_name = "enable",
-    .head = QTAILQ_HEAD_INITIALIZER(qemu_trace_opts.head),
-    .desc = {
-        {
-            .name = "enable",
-            .type = QEMU_OPT_STRING,
-        },
-        {
-            .name = "events",
-            .type = QEMU_OPT_STRING,
-        },{
-            .name = "file",
-            .type = QEMU_OPT_STRING,
-        },
-        { /* end of list */ }
-    },
-};
-
 static QemuOptsList qemu_option_rom_opts = {
     .name = "option-rom",
     .implied_opt_name = "romfile",
@@ -3864,23 +3844,9 @@ int main(int argc, char **argv, char **envp)
                 xen_mode = XEN_ATTACH;
                 break;
             case QEMU_OPTION_trace:
-            {
+                g_free(trace_file);
-                opts = qemu_opts_parse_noisily(qemu_find_opts("trace"),
+                trace_file = trace_opt_parse(optarg);
-                                               optarg, true);
-                if (!opts) {
-                    exit(1);
-                }
-                if (qemu_opt_get(opts, "enable")) {
-                    trace_enable_events(qemu_opt_get(opts, "enable"));
-                }
-                trace_init_events(qemu_opt_get(opts, "events"));
-                if (trace_file) {
-                    g_free(trace_file);
-                }
-                trace_file = g_strdup(qemu_opt_get(opts, "file"));
-                qemu_opts_del(opts);
                 break;
-            }
             case QEMU_OPTION_readconfig:
                 {
                     int ret = qemu_read_config_file(optarg);