perf trace: Beautify wait4/waitid 'options' argument

  # trace -e waitid,wait4

   0.557 ( 0.557 ms): bash/27335 wait4(upid: -1, stat_addr: 0x7ffd02f449f0) = 27336
   1.250 ( 0.685 ms): bash/27335 wait4(upid: -1, stat_addr: 0x7ffd02f449f0) = 27337
   1.312 ( 0.002 ms): bash/27335 wait4(upid: -1, stat_addr: 0x7ffd02f44690, options: NOHANG) = -1 ECHILD No child processes
   1.550 ( 0.015 ms): bash/3856 wait4(upid: -1, stat_addr: 0x7ffd02f44990, options: NOHANG|UNTRACED|CONTINUED) = 27335
   1.552 ( 0.001 ms): bash/3856 wait4(upid: -1, stat_addr: 0x7ffd02f44990, options: NOHANG|UNTRACED|CONTINUED) = 0
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-i5vlo5n5jv0amt8bkyicmdxh@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-trace.c

@@ -1074,6 +1074,7 @@ static size_t syscall_arg__scnprintf_getrandom_flags(char *bf, size_t size,
 	  .arg_parm	 = { [arg] = &strarray__##array, }
 
 #include "trace/beauty/sched_policy.c"
+#include "trace/beauty/waitid_options.c"
 
 static struct syscall_fmt {
 	const char *name;
@@ -1364,6 +1365,10 @@ static struct syscall_fmt {
 	  .arg_scnprintf = { [0] = SCA_FILENAME, /* filename */ }, },
 	{ .name	    = "vmsplice",  .errmsg = true,
 	  .arg_scnprintf = { [0] = SCA_FD, /* fd */ }, },
+	{ .name	    = "wait4",	    .errmsg = true,
+	  .arg_scnprintf = { [2] = SCA_WAITID_OPTIONS, /* options */ }, },
+	{ .name	    = "waitid",	    .errmsg = true,
+	  .arg_scnprintf = { [3] = SCA_WAITID_OPTIONS, /* options */ }, },
 	{ .name	    = "write",	    .errmsg = true,
 	  .arg_scnprintf = { [0] = SCA_FD, /* fd */ }, },
 	{ .name	    = "writev",	    .errmsg = true,

tools/perf/trace/beauty/waitid_options.c

@@ -0,0 +1,26 @@
+#include <sys/types.h>
+#include <sys/wait.h>
+
+static size_t syscall_arg__scnprintf_waitid_options(char *bf, size_t size,
+						    struct syscall_arg *arg)
+{
+	int printed = 0, options = arg->val;
+
+#define	P_OPTION(n) \
+	if (options & W##n) { \
+		printed += scnprintf(bf + printed, size - printed, "%s%s", printed ? "|" : "", #n); \
+		options &= ~W##n; \
+	}
+
+	P_OPTION(NOHANG);
+	P_OPTION(UNTRACED);
+	P_OPTION(CONTINUED);
+#undef P_OPTION
+
+	if (options)
+		printed += scnprintf(bf + printed, size - printed, "%s%#x", printed ? "|" : "", options);
+
+	return printed;
+}
+
+#define SCA_WAITID_OPTIONS syscall_arg__scnprintf_waitid_options