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 <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1470214725-5023-1-git-send-email-ravi.bangoria@linux.vnet.ibm.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/probe-event.c

@@ -1618,19 +1618,27 @@ int parse_perf_probe_command(const char *cmd, struct perf_probe_event *pev)
 	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

@@ -128,6 +128,8 @@ char *synthesize_perf_probe_point(struct perf_probe_point *pp);
 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);