perf tests: Add is_printable_array test

Add automated test for is_printable_array function.

Signed-off-by: Jiri Olsa <[e-mail]>
Cc: David Ahern <[e-mail]>
Cc: Jiri Pirko <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Steven Rostedt <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/tests/Build

···
 perf-y += event-times.o
 perf-y += backward-ring-buffer.o
 perf-y += sdt.o
+perf-y += is_printable_array.o
 
 $(OUTPUT)tests/llvm-src-base.c: tests/bpf-script-example.c tests/Build
 	$(call rule_mkdir)

tools/perf/tests/builtin-test.c

···
 		.func = test__sdt_event,
 	},
 	{
+		.desc = "Test is_printable_array function",
+		.func = test__is_printable_array,
+	},
+	{
 		.func = NULL,
 	},
 };

tools/perf/tests/is_printable_array.c

···
+#include <linux/compiler.h>
+#include "tests.h"
+#include "debug.h"
+#include "util.h"
+
+int test__is_printable_array(int subtest __maybe_unused)
+{
+	char buf1[] = { 'k', 'r', 4, 'v', 'a', 0 };
+	char buf2[] = { 'k', 'r', 'a', 'v', 4, 0 };
+	struct {
+		char		*buf;
+		unsigned int	 len;
+		int		 ret;
+	} t[] = {
+		{ (char *) "krava",	sizeof("krava"),	1 },
+		{ (char *) "krava",	sizeof("krava") - 1,	0 },
+		{ (char *) "",		sizeof(""),		1 },
+		{ (char *) "",		0,			0 },
+		{ NULL,			0,			0 },
+		{ buf1,			sizeof(buf1),		0 },
+		{ buf2,			sizeof(buf2),		0 },
+	};
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(t); i++) {
+		int ret;
+
+		ret = is_printable_array((char *) t[i].buf, t[i].len);
+		if (ret != t[i].ret) {
+			pr_err("failed: test %u\n", i);
+			return TEST_FAIL;
+		}
+	}
+
+	return TEST_OK;
+}

tools/perf/tests/tests.h

···
 int test__backward_ring_buffer(int subtest);
 int test__cpu_map_print(int subtest);
 int test__sdt_event(int subtest);
+int test__is_printable_array(int subtest);
 
 #if defined(__arm__) || defined(__aarch64__)
 #ifdef HAVE_DWARF_UNWIND_SUPPORT