perf probe: Add helper function to check if probe with variable

Introduce helper function instead of inline code and replace hardcoded
strings "$vars" and "$params" with their corresponding macros.

perf_probe_with_var() is not declared as static since it will be called
from different file in subsequent patch.

Signed-off-by: Ravi Bangoria <[e-mail]>
Acked-by: Masami Hiramatsu <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Hemant Kumar <[e-mail]>
Cc: Naveen N. Rao <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Wang Nan <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/probe-event.c

···
 	return ret;
 }
 
+/* Returns true if *any* ARG is either C variable, $params or $vars. */
+bool perf_probe_with_var(struct perf_probe_event *pev)
+{
+	int i = 0;
+
+	for (i = 0; i < pev->nargs; i++)
+		if (is_c_varname(pev->args[i].var)              ||
+		    !strcmp(pev->args[i].var, PROBE_ARG_PARAMS) ||
+		    !strcmp(pev->args[i].var, PROBE_ARG_VARS))
+			return true;
+	return false;
+}
+
 /* Return true if this perf_probe_event requires debuginfo */
 bool perf_probe_event_need_dwarf(struct perf_probe_event *pev)
 {
-	int i;
-
 	if (pev->point.file || pev->point.line || pev->point.lazy_line)
 		return true;
 
-	for (i = 0; i < pev->nargs; i++)
-		if (is_c_varname(pev->args[i].var) ||
-		    !strcmp(pev->args[i].var, "$params") ||
-		    !strcmp(pev->args[i].var, "$vars"))
-			return true;
+	if (perf_probe_with_var(pev))
+		return true;
 
 	return false;
 }

tools/perf/util/probe-event.h

···
 int perf_probe_event__copy(struct perf_probe_event *dst,
 			   struct perf_probe_event *src);
 
+bool perf_probe_with_var(struct perf_probe_event *pev);
+
 /* Check the perf_probe_event needs debuginfo */
 bool perf_probe_event_need_dwarf(struct perf_probe_event *pev);