1 files changed, 169 insertions, 0 deletions
diff --git a/trace/control.c b/trace/control.c
new file mode 100644
index 00000000..995beb38
--- /dev/null
+++ b/trace/control.c
@@ -0,0 +1,169 @@
+/*
+ * 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;
+}