Provide the missing LIBUSB_LOG_LEVEL_* for older libusb or FreeBSD. Providing just...
[qemu.git] / trace / control.c
1 /*
2 * Interface for configuring and controlling the state of tracing events.
3 *
4 * Copyright (C) 2011-2014 LluĂ­s Vilanova <vilanova@ac.upc.edu>
5 *
6 * This work is licensed under the terms of the GNU GPL, version 2 or later.
7 * See the COPYING file in the top-level directory.
8 */
9
10 #include "trace/control.h"
11 #ifdef CONFIG_TRACE_SIMPLE
12 #include "trace/simple.h"
13 #endif
14 #ifdef CONFIG_TRACE_FTRACE
15 #include "trace/ftrace.h"
16 #endif
17 #include "qemu/error-report.h"
18
19 TraceEvent *trace_event_name(const char *name)
20 {
21 assert(name != NULL);
22
23 TraceEventID i;
24 for (i = 0; i < trace_event_count(); i++) {
25 TraceEvent *ev = trace_event_id(i);
26 if (strcmp(trace_event_get_name(ev), name) == 0) {
27 return ev;
28 }
29 }
30 return NULL;
31 }
32
33 static bool pattern_glob(const char *pat, const char *ev)
34 {
35 while (*pat != '\0' && *ev != '\0') {
36 if (*pat == *ev) {
37 pat++;
38 ev++;
39 }
40 else if (*pat == '*') {
41 if (pattern_glob(pat, ev+1)) {
42 return true;
43 } else if (pattern_glob(pat+1, ev)) {
44 return true;
45 } else {
46 return false;
47 }
48 } else {
49 return false;
50 }
51 }
52
53 while (*pat == '*') {
54 pat++;
55 }
56
57 if (*pat == '\0' && *ev == '\0') {
58 return true;
59 } else {
60 return false;
61 }
62 }
63
64 TraceEvent *trace_event_pattern(const char *pat, TraceEvent *ev)
65 {
66 assert(pat != NULL);
67
68 TraceEventID i;
69
70 if (ev == NULL) {
71 i = -1;
72 } else {
73 i = trace_event_get_id(ev);
74 }
75 i++;
76
77 while (i < trace_event_count()) {
78 TraceEvent *res = trace_event_id(i);
79 if (pattern_glob(pat, trace_event_get_name(res))) {
80 return res;
81 }
82 i++;
83 }
84
85 return NULL;
86 }
87
88 static void trace_init_events(const char *fname)
89 {
90 Location loc;
91 FILE *fp;
92 char line_buf[1024];
93 size_t line_idx = 0;
94
95 if (fname == NULL) {
96 return;
97 }
98
99 loc_push_none(&loc);
100 loc_set_file(fname, 0);
101 fp = fopen(fname, "r");
102 if (!fp) {
103 error_report("%s", strerror(errno));
104 exit(1);
105 }
106 while (fgets(line_buf, sizeof(line_buf), fp)) {
107 loc_set_file(fname, ++line_idx);
108 size_t len = strlen(line_buf);
109 if (len > 1) { /* skip empty lines */
110 line_buf[len - 1] = '\0';
111 if ('#' == line_buf[0]) { /* skip commented lines */
112 continue;
113 }
114 const bool enable = ('-' != line_buf[0]);
115 char *line_ptr = enable ? line_buf : line_buf + 1;
116 if (trace_event_is_pattern(line_ptr)) {
117 TraceEvent *ev = NULL;
118 while ((ev = trace_event_pattern(line_ptr, ev)) != NULL) {
119 if (trace_event_get_state_static(ev)) {
120 trace_event_set_state_dynamic(ev, enable);
121 }
122 }
123 } else {
124 TraceEvent *ev = trace_event_name(line_ptr);
125 if (ev == NULL) {
126 error_report("WARNING: trace event '%s' does not exist",
127 line_ptr);
128 } else if (!trace_event_get_state_static(ev)) {
129 error_report("WARNING: trace event '%s' is not traceable\n",
130 line_ptr);
131 } else {
132 trace_event_set_state_dynamic(ev, enable);
133 }
134 }
135 }
136 }
137 if (fclose(fp) != 0) {
138 loc_set_file(fname, 0);
139 error_report("%s", strerror(errno));
140 exit(1);
141 }
142 loc_pop(&loc);
143 }
144
145 bool trace_init_backends(const char *events, const char *file)
146 {
147 #ifdef CONFIG_TRACE_SIMPLE
148 if (!st_init(file)) {
149 fprintf(stderr, "failed to initialize simple tracing backend.\n");
150 return false;
151 }
152 #else
153 if (file) {
154 fprintf(stderr, "error: -trace file=...: "
155 "option not supported by the selected tracing backends\n");
156 return false;
157 }
158 #endif
159
160 #ifdef CONFIG_TRACE_FTRACE
161 if (!ftrace_init()) {
162 fprintf(stderr, "failed to initialize ftrace backend.\n");
163 return false;
164 }
165 #endif
166
167 trace_init_events(events);
168 return true;
169 }