xref: /qemu/scripts/tracetool/backend/simple.py (revision 72ac97cd) 
1#!/usr/bin/env python
2# -*- coding: utf-8 -*-
3
4"""
5Simple built-in backend.
6"""
7
8__author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
9__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
10__license__    = "GPL version 2 or (at your option) any later version"
11
12__maintainer__ = "Stefan Hajnoczi"
13__email__      = "stefanha@linux.vnet.ibm.com"
14
15
16from tracetool import out
17
18
19PUBLIC = True
20
21
22def is_string(arg):
23    strtype = ('const char*', 'char*', 'const char *', 'char *')
24    if arg.lstrip().startswith(strtype):
25        return True
26    else:
27        return False
28
29
30def generate_h_begin(events):
31    for event in events:
32        out('void _simple_%(api)s(%(args)s);',
33            api=event.api(),
34            args=event.args)
35    out('')
36
37
38def generate_h(event):
39    out('    _simple_%(api)s(%(args)s);',
40        api=event.api(),
41        args=", ".join(event.args.names()))
42
43
44def generate_c_begin(events):
45    out('#include "trace.h"',
46        '#include "trace/control.h"',
47        '#include "trace/simple.h"',
48        '')
49
50
51def generate_c(event):
52    out('void _simple_%(api)s(%(args)s)',
53        '{',
54        '    TraceBufferRecord rec;',
55        api=event.api(),
56        args=event.args)
57    sizes = []
58    for type_, name in event.args:
59        if is_string(type_):
60            out('    size_t arg%(name)s_len = %(name)s ? MIN(strlen(%(name)s), MAX_TRACE_STRLEN) : 0;',
61                name=name)
62            strsizeinfo = "4 + arg%s_len" % name
63            sizes.append(strsizeinfo)
64        else:
65            sizes.append("8")
66    sizestr = " + ".join(sizes)
67    if len(event.args) == 0:
68        sizestr = '0'
69
70
71    out('',
72        '    if (!trace_event_get_state(%(event_id)s)) {',
73        '        return;',
74        '    }',
75        '',
76        '    if (trace_record_start(&rec, %(event_id)s, %(size_str)s)) {',
77        '        return; /* Trace Buffer Full, Event Dropped ! */',
78        '    }',
79        event_id='TRACE_' + event.name.upper(),
80        size_str=sizestr)
81
82    if len(event.args) > 0:
83        for type_, name in event.args:
84            # string
85            if is_string(type_):
86                out('    trace_record_write_str(&rec, %(name)s, arg%(name)s_len);',
87                    name=name)
88            # pointer var (not string)
89            elif type_.endswith('*'):
90                out('    trace_record_write_u64(&rec, (uintptr_t)(uint64_t *)%(name)s);',
91                    name=name)
92            # primitive data type
93            else:
94                out('    trace_record_write_u64(&rec, (uint64_t)%(name)s);',
95                   name=name)
96
97    out('    trace_record_finish(&rec);',
98        '}',
99        '')
100