trace: convert stderr backend to log

[Also update .travis.yml --enable-trace-backends=stderr
--Stefan]

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: 1452174932-28657-10-git-send-email-den@openvz.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

scripts/tracetool/backend/log.py

@@ -0,0 +1,48 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+"""
+Stderr built-in backend.
+"""
+
+__author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
+__license__    = "GPL version 2 or (at your option) any later version"
+
+__maintainer__ = "Stefan Hajnoczi"
+__email__      = "stefanha@linux.vnet.ibm.com"
+
+
+from tracetool import out
+
+
+PUBLIC = True
+
+
+def generate_h_begin(events):
+    out('#include <stdio.h>',
+        '#include <sys/time.h>',
+        '#include <sys/types.h>',
+        '#include <unistd.h>',
+        '#include "trace/control.h"',
+        '#include "qemu/log.h"',
+        '')
+
+
+def generate_h(event):
+    argnames = ", ".join(event.args.names())
+    if len(event.args) > 0:
+        argnames = ", " + argnames
+
+    out('    if (trace_event_get_state(%(event_id)s)) {',
+        '        struct timeval _now;',
+        '        gettimeofday(&_now, NULL);',
+        '        qemu_log_mask(LOG_TRACE, "%%d@%%zd.%%06zd:%(name)s " %(fmt)s "\\n",',
+        '                      getpid(),',
+        '                      (size_t)_now.tv_sec, (size_t)_now.tv_usec',
+        '                      %(argnames)s);',
+        '    }',
+        event_id="TRACE_" + event.name.upper(),
+        name=event.name,
+        fmt=event.fmt.rstrip("\n"),
+        argnames=argnames)