perf script: Make printing flags reliable

Add a check for the generated string of flags. Print out the raw number
if the string generation fails.

Use the SAMPLE_FLAGS_STR_ALIGNED_SIZE macro to replace the value '21'.

Reviewed-by: Ian Rogers <[e-mail]>
Reviewed-by: James Clark <[e-mail]>
Signed-off-by: Leo Yan <[e-mail]>
Reviewed-by: Adrian Hunter <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Namhyung Kim <[e-mail]>

tools/perf/builtin-script.c

···
 static int perf_sample__fprintf_flags(u32 flags, FILE *fp)
 {
 	char str[SAMPLE_FLAGS_BUF_SIZE];
+	int ret;
 
-	perf_sample__sprintf_flags(flags, str, sizeof(str));
-	return fprintf(fp, "  %-21s ", str);
+	ret = perf_sample__sprintf_flags(flags, str, sizeof(str));
+	if (ret < 0)
+		return fprintf(fp, "  raw flags:0x%-*x ",
+			       SAMPLE_FLAGS_STR_ALIGNED_SIZE - 12, flags);
+
+	return fprintf(fp, "  %-*s ", SAMPLE_FLAGS_STR_ALIGNED_SIZE, str);
 }
 
 struct printer_data {

tools/perf/util/trace-event.h

···
 int common_lock_depth(struct scripting_context *context);
 
 #define SAMPLE_FLAGS_BUF_SIZE 64
+#define SAMPLE_FLAGS_STR_ALIGNED_SIZE	21
+
 int perf_sample__sprintf_flags(u32 flags, char *str, size_t sz);
 
 #if defined(LIBTRACEEVENT_VERSION) &&  LIBTRACEEVENT_VERSION >= MAKE_LIBTRACEEVENT_VERSION(1, 5, 0)