perf list: Allow wordwrap to wrap on commas

A raw event encoding may be a block with terms separated by commas. If
wrapping such a string it would be useful to break at the commas, so
add this ability to wordwrap.

Signed-off-by: Ian Rogers <[e-mail]>
Tested-by: Kan Liang <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: James Clark <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Ravi Bangoria <[e-mail]>
Cc: Yang Jihong <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/builtin-list.c

···
 #include <subcmd/pager.h>
 #include <subcmd/parse-options.h>
 #include <linux/zalloc.h>
+#include <ctype.h>
 #include <stdarg.h>
 #include <stdio.h>
 
···
 
 static void default_print_end(void *print_state __maybe_unused) {}
 
+static const char *skip_spaces_or_commas(const char *str)
+{
+	while (isspace(*str) || *str == ',')
+		++str;
+	return str;
+}
+
 static void wordwrap(FILE *fp, const char *s, int start, int max, int corr)
 {
 	int column = start;
 	int n;
 	bool saw_newline = false;
+	bool comma = false;
 
 	while (*s) {
-		int wlen = strcspn(s, " \t\n");
+		int wlen = strcspn(s, " ,\t\n");
+		const char *sep = comma ? "," : " ";
 
 		if ((column + wlen >= max && column > start) || saw_newline) {
-			fprintf(fp, "\n%*s", start, "");
+			fprintf(fp, comma ? ",\n%*s" : "\n%*s", start, "");
 			column = start + corr;
 		}
-		n = fprintf(fp, "%s%.*s", column > start ? " " : "", wlen, s);
+		if (column <= start)
+			sep = "";
+		n = fprintf(fp, "%s%.*s", sep, wlen, s);
 		if (n <= 0)
 			break;
 		saw_newline = s[wlen] == '\n';
 		s += wlen;
+		comma = s[0] == ',';
 		column += n;
-		s = skip_spaces(s);
+		s = skip_spaces_or_commas(s);
 	}
 }