trace-cmd: Add -T option to report to test filters

Add the -T option to print the filter strings created by -F
and exit.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

3 files changed, 19 insertions, 2 deletions

diff --git a/Documentation/trace-cmd-report.1.txt b/Documentation/trace-cmd-report.1.txt
index 86169f2..148f9d9 100644
--- a/Documentation/trace-cmd-report.1.txt
+++ b/Documentation/trace-cmd-report.1.txt
@@ -117,6 +117,14 @@ OPTIONS
     Will not display any sched_switch events that have a prev_state of 0.
     Removing the *-v* will only print out those events.
 
+*-T*::
+    Test the filters of -F. After processing a filter string, the
+    resulting filter will be displayed for each event. This is useful
+    for using a filter for more than one event where a field may not
+    exist in all events. Also it can be used to make sure there are no
+    misspelled event field names, as they will simply be ignored.
+    *-T* is ignored if *-F* is not specified.
+
 *-V*::
     Show the plugins that are loaded.
 
diff --git a/trace-read.c b/trace-read.c
index a4c3538..37a7bc4 100644
--- a/trace-read.c
+++ b/trace-read.c
@@ -688,6 +688,7 @@ void trace_report (int argc, char **argv)
         int latency_format = 0;
         int show_events = 0;
         int print_events = 0;
+        int test_filters = 0;
         int raw = 0;
         int neg = 0;
         int c;
@@ -705,11 +706,12 @@ void trace_report (int argc, char **argv)
                 static struct option long_options[] = {
                         {"cpu", required_argument, NULL, 0},
                         {"events", no_argument, NULL, 0},
+                        {"filter-test", no_argument, NULL, 'T'},
                         {"help", no_argument, NULL, '?'},
                         {NULL, 0, NULL, 0}
                 };
 
-                c = getopt_long (argc-1, argv+1, "+hi:feprPNLlEwF:Vvq",
+                c = getopt_long (argc-1, argv+1, "+hi:feprPNLlEwF:VvTq",
                         long_options, &option_index);
                 if (c == -1)
                         break;
@@ -723,6 +725,9 @@ void trace_report (int argc, char **argv)
                 case 'F':
                         add_filter(optarg, neg);
                         break;
+                case 'T':
+                        test_filters = 1;
+                        break;
                 case 'f':
                         show_funcs = 1;
                         break;
@@ -811,6 +816,9 @@ void trace_report (int argc, char **argv)
         if (raw)
                 pevent->print_raw = 1;
 
+        if (test_filters)
+                pevent->test_filters = 1;
+
         if (show_endian) {
                 printf("file is %s endian and host is %s endian\n",
                        pevent_is_file_bigendian(pevent) ? "big" : "little",
diff --git a/trace-usage.c b/trace-usage.c
index a6280e8..88f744c 100644
--- a/trace-usage.c
+++ b/trace-usage.c
@@ -71,7 +71,7 @@ static struct usage_help usage_help[] = {
                 "report",
                 "read out the trace stored in a trace.dat file",
                 " %s report [-i file] [--cpu cpu] [-e][-f][-l][-P][-L][-N][-r][-E]\\\n"
-                "           [-F filter][-v][-V]\n"
+                "           [-F filter][-v][-V][-T]\n"
                 "          -i input file [default trace.dat]\n"
                 "          -e show file endianess\n"
                 "          -f show function list\n"
@@ -80,6 +80,7 @@ static struct usage_help usage_help[] = {
                 "          -F filter to filter output on\n"
                 "          -r raw format: ignore print format and only show field data\n"
                 "          -v will negate all -F after it (Not show matches)\n"
+                "          -T print out the filter strings created and exit\n"
                 "          -V verbose (shows plugins being loaded)\n"
                 "          -L load only local (~/.trace-cmd/plugins) plugins\n"
                 "          -N do not load any plugins\n"