xref: /qemu/scripts/tracetool/backend/ftrace.py (revision 727385c4)
1# -*- coding: utf-8 -*-
2
3"""
4Ftrace built-in backend.
5"""
6
7__author__     = "Eiichi Tsukata <eiichi.tsukata.xh@hitachi.com>"
8__copyright__  = "Copyright (C) 2013 Hitachi, Ltd."
9__license__    = "GPL version 2 or (at your option) any later version"
10
11__maintainer__ = "Stefan Hajnoczi"
12__email__      = "stefanha@redhat.com"
13
14
15from tracetool import out
16
17
18PUBLIC = True
19
20
21def generate_h_begin(events, group):
22    out('#include "trace/ftrace.h"',
23        '')
24
25
26def generate_h(event, group):
27    argnames = ", ".join(event.args.names())
28    if len(event.args) > 0:
29        argnames = ", " + argnames
30
31    out('    {',
32        '        char ftrace_buf[MAX_TRACE_STRLEN];',
33        '        int unused __attribute__ ((unused));',
34        '        int trlen;',
35        '        if (trace_event_get_state(%(event_id)s)) {',
36        '#line %(event_lineno)d "%(event_filename)s"',
37        '            trlen = snprintf(ftrace_buf, MAX_TRACE_STRLEN,',
38        '                             "%(name)s " %(fmt)s "\\n" %(argnames)s);',
39        '#line %(out_next_lineno)d "%(out_filename)s"',
40        '            trlen = MIN(trlen, MAX_TRACE_STRLEN - 1);',
41        '            unused = write(trace_marker_fd, ftrace_buf, trlen);',
42        '        }',
43        '    }',
44        name=event.name,
45        args=event.args,
46        event_id="TRACE_" + event.name.upper(),
47        event_lineno=event.lineno,
48        event_filename=event.filename,
49        fmt=event.fmt.rstrip("\n"),
50        argnames=argnames)
51
52
53def generate_h_backend_dstate(event, group):
54    out('    trace_event_get_state_dynamic_by_id(%(event_id)s) || \\',
55        event_id="TRACE_" + event.name.upper())
56