summaryrefslogtreecommitdiff
path: root/trace/control.c
blob: 995beb384c13a0c716ac1dba1e164e92ab026cd6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
/*
 * Interface for configuring and controlling the state of tracing events.
 *
 * Copyright (C) 2011-2014 Lluís Vilanova <vilanova@ac.upc.edu>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 */

#include "trace/control.h"
#ifdef CONFIG_TRACE_SIMPLE
#include "trace/simple.h"
#endif
#ifdef CONFIG_TRACE_FTRACE
#include "trace/ftrace.h"
#endif
#include "qemu/error-report.h"

TraceEvent *trace_event_name(const char *name)
{
    assert(name != NULL);

    TraceEventID i;
    for (i = 0; i < trace_event_count(); i++) {
        TraceEvent *ev = trace_event_id(i);
        if (strcmp(trace_event_get_name(ev), name) == 0) {
            return ev;
        }
    }
    return NULL;
}

static bool pattern_glob(const char *pat, const char *ev)
{
    while (*pat != '\0' && *ev != '\0') {
        if (*pat == *ev) {
            pat++;
            ev++;
        }
        else if (*pat == '*') {
            if (pattern_glob(pat, ev+1)) {
                return true;
            } else if (pattern_glob(pat+1, ev)) {
                return true;
            } else {
                return false;
            }
        } else {
            return false;
        }
    }

    while (*pat == '*') {
        pat++;
    }

    if (*pat == '\0' && *ev == '\0') {
        return true;
    } else {
        return false;
    }
}

TraceEvent *trace_event_pattern(const char *pat, TraceEvent *ev)
{
    assert(pat != NULL);

    TraceEventID i;

    if (ev == NULL) {
        i = -1;
    } else {
        i = trace_event_get_id(ev);
    }
    i++;

    while (i < trace_event_count()) {
        TraceEvent *res = trace_event_id(i);
        if (pattern_glob(pat, trace_event_get_name(res))) {
            return res;
        }
        i++;
    }

    return NULL;
}

static void trace_init_events(const char *fname)
{
    Location loc;
    FILE *fp;
    char line_buf[1024];
    size_t line_idx = 0;

    if (fname == NULL) {
        return;
    }

    loc_push_none(&loc);
    loc_set_file(fname, 0);
    fp = fopen(fname, "r");
    if (!fp) {
        error_report("%s", strerror(errno));
        exit(1);
    }
    while (fgets(line_buf, sizeof(line_buf), fp)) {
        loc_set_file(fname, ++line_idx);
        size_t len = strlen(line_buf);
        if (len > 1) {              /* skip empty lines */
            line_buf[len - 1] = '\0';
            if ('#' == line_buf[0]) { /* skip commented lines */
                continue;
            }
            const bool enable = ('-' != line_buf[0]);
            char *line_ptr = enable ? line_buf : line_buf + 1;
            if (trace_event_is_pattern(line_ptr)) {
                TraceEvent *ev = NULL;
                while ((ev = trace_event_pattern(line_ptr, ev)) != NULL) {
                    if (trace_event_get_state_static(ev)) {
                        trace_event_set_state_dynamic(ev, enable);
                    }
                }
            } else {
                TraceEvent *ev = trace_event_name(line_ptr);
                if (ev == NULL) {
                    error_report("WARNING: trace event '%s' does not exist",
                                 line_ptr);
                } else if (!trace_event_get_state_static(ev)) {
                    error_report("WARNING: trace event '%s' is not traceable",
                                 line_ptr);
                } else {
                    trace_event_set_state_dynamic(ev, enable);
                }
            }
        }
    }
    if (fclose(fp) != 0) {
        loc_set_file(fname, 0);
        error_report("%s", strerror(errno));
        exit(1);
    }
    loc_pop(&loc);
}

bool trace_init_backends(const char *events, const char *file)
{
#ifdef CONFIG_TRACE_SIMPLE
    if (!st_init(file)) {
        fprintf(stderr, "failed to initialize simple tracing backend.\n");
        return false;
    }
#else
    if (file) {
        fprintf(stderr, "error: -trace file=...: "
                "option not supported by the selected tracing backends\n");
        return false;
    }
#endif

#ifdef CONFIG_TRACE_FTRACE
    if (!ftrace_init()) {
        fprintf(stderr, "failed to initialize ftrace backend.\n");
        return false;
    }
#endif

    trace_init_events(events);
    return true;
}