Re: [PATCH v2 1/4] perf tools: Create for_each_event macro for tracepoints iteration

[Taeung Song]

Hi, Arnaldo :)

On 01/31/2017 09:21 PM, Arnaldo Carvalho de Melo wrote:

Em Tue, Jan 31, 2017 at 08:38:28PM +0900, Taeung Song escreveu:

Such as for_each_subsystem and for_each_event in util/parse-events.c,
add new macros 'for_each_event' for easy iteration over the tracepoints
in order to be more compact and readable.

Looks ok, applied, but look below for some minor suggestions.

- Arnaldo

Cc: Steven Rostedt <rost...@goodmis.org>
Cc: Frederic Weisbecker <fweis...@gmail.com>
Cc: Jiri Olsa <jo...@kernel.org>
Cc: Namhyung Kim <namhy...@kernel.org>
Signed-off-by: Taeung Song <treeze.tae...@gmail.com>
---
 tools/perf/util/trace-event-info.c | 38 ++++++++++++++++++--------------------
 1 file changed, 18 insertions(+), 20 deletions(-)

diff --git a/tools/perf/util/trace-event-info.c 
b/tools/perf/util/trace-event-info.c
index ceb0e27..fb6d95d 100644
--- a/tools/perf/util/trace-event-info.c
+++ b/tools/perf/util/trace-event-info.c
@@ -170,6 +170,12 @@ static bool name_in_tp_list(char *sys, struct 
tracepoint_path *tps)
        return false;
 }

+#define for_each_event(dir, dent, tps)                         \
+       while ((dent = readdir(dir)))                           \
+               if (dent->d_type == DT_DIR &&                        \
+                   (strcmp(dent->d_name, ".")) &&         \
+                   (strcmp(dent->d_name, "..")))          \
+
 static int copy_event_system(const char *sys, struct tracepoint_path *tps)
 {
        struct dirent *dent;
@@ -186,12 +192,10 @@ static int copy_event_system(const char *sys, struct 
tracepoint_path *tps)
                return -errno;
        }

-       while ((dent = readdir(dir))) {
-               if (dent->d_type != DT_DIR ||
-                   strcmp(dent->d_name, ".") == 0 ||
-                   strcmp(dent->d_name, "..") == 0 ||
-                   !name_in_tp_list(dent->d_name, tps))
+       for_each_event(dir, dent, tps) {
+               if (!name_in_tp_list(dent->d_name, tps))
                        continue;
+
                if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) {
                        err = -ENOMEM;
                        goto out;
@@ -210,12 +214,10 @@ static int copy_event_system(const char *sys, struct 
tracepoint_path *tps)
        }

        rewinddir(dir);
-       while ((dent = readdir(dir))) {
-               if (dent->d_type != DT_DIR ||
-                   strcmp(dent->d_name, ".") == 0 ||
-                   strcmp(dent->d_name, "..") == 0 ||
-                   !name_in_tp_list(dent->d_name, tps))
+       for_each_event(dir, dent, tps) {
+               if (!name_in_tp_list(dent->d_name, tps))
                        continue;
+
                if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) {
                        err = -ENOMEM;
                        goto out;
@@ -290,13 +292,11 @@ static int record_event_files(struct tracepoint_path *tps)
                goto out;
        }

-       while ((dent = readdir(dir))) {
-               if (dent->d_type != DT_DIR ||
-                   strcmp(dent->d_name, ".") == 0 ||
-                   strcmp(dent->d_name, "..") == 0 ||
-                   strcmp(dent->d_name, "ftrace") == 0 ||
+       for_each_event(dir, dent, tps) {
+               if (!strcmp(dent->d_name, "ftrace") ||

the existing style was == 0, you switched it to !, equivalent, but
gratuitous, keeping the existing style would make reviewing slightly
faster, as the pattern wouldn't have changed.

I understood !!
In the future, I'll think this when making some patches.

Thanks,
Taeung