perf trace: Factor out the initialization of syscal_arg_fmt->scnprintf

We set the default scnprint routines for the syscall args based on its
type or on heuristics based on its names, now we'll use this for
tracepoints as well, so move it out of syscall__set_arg_fmts() and into
a routine that receive just an array of syscall_arg_fmt entries + the
tracepoint format fields list.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-xs3x0zzyes06c7scdsjn01ty@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-trace.c

@@ -1467,15 +1467,16 @@ static int syscall__alloc_arg_fmts(struct syscall *sc, int nr_args)
 	return 0;
 }
 
-static int syscall__set_arg_fmts(struct syscall *sc)
+static struct tep_format_field *
+syscall_arg_fmt__init_array(struct syscall_arg_fmt *arg, struct tep_format_field *field)
 {
-	struct tep_format_field *field, *last_field = NULL;
-	int idx = 0, len;
+	struct tep_format_field *last_field = NULL;
+	int len;
 
-	for (field = sc->args; field; field = field->next, ++idx) {
+	for (; field; field = field->next, ++arg) {
 		last_field = field;
 
-		if (sc->fmt && sc->fmt->arg[idx].scnprintf)
+		if (arg->scnprintf)
 			continue;
 
 		len = strlen(field->name);
@@ -1483,13 +1484,13 @@ static int syscall__set_arg_fmts(struct syscall *sc)
 		if (strcmp(field->type, "const char *") == 0 &&
 		    ((len >= 4 && strcmp(field->name + len - 4, "name") == 0) ||
 		     strstr(field->name, "path") != NULL))
-			sc->arg_fmt[idx].scnprintf = SCA_FILENAME;
+			arg->scnprintf = SCA_FILENAME;
 		else if ((field->flags & TEP_FIELD_IS_POINTER) || strstr(field->name, "addr"))
-			sc->arg_fmt[idx].scnprintf = SCA_PTR;
+			arg->scnprintf = SCA_PTR;
 		else if (strcmp(field->type, "pid_t") == 0)
-			sc->arg_fmt[idx].scnprintf = SCA_PID;
+			arg->scnprintf = SCA_PID;
 		else if (strcmp(field->type, "umode_t") == 0)
-			sc->arg_fmt[idx].scnprintf = SCA_MODE_T;
+			arg->scnprintf = SCA_MODE_T;
 		else if ((strcmp(field->type, "int") == 0 ||
 			  strcmp(field->type, "unsigned int") == 0 ||
 			  strcmp(field->type, "long") == 0) &&
@@ -1501,10 +1502,17 @@ static int syscall__set_arg_fmts(struct syscall *sc)
 			 * 23 unsigned int
 			 * 7 unsigned long
 			 */
-			sc->arg_fmt[idx].scnprintf = SCA_FD;
+			arg->scnprintf = SCA_FD;
 		}
 	}
 
+	return last_field;
+}
+
+static int syscall__set_arg_fmts(struct syscall *sc)
+{
+	struct tep_format_field *last_field = syscall_arg_fmt__init_array(sc->arg_fmt, sc->args);
+
 	if (last_field)
 		sc->args_size = last_field->offset + last_field->size;