perf test: Add test cases for new data source encoding

Add some simple tests to perf test to test data source printing.

v2: Make the tests actually checked for the correct name of Forward
v3: Adjust to new encoding

Committer notes:

Avoid the in place declaration to make this build with older compilers,
for instance, in Debian 7 we get:

  tests/mem.c: In function 'test__mem':
  tests/mem.c:30:5: error: missing initializer [-Werror=missing-field-initializers]
  tests/mem.c:30:5: error: (near initialization for '(anonymous).<anonymous>.mem_snoop') [-Werror=missing-field-initializers]

So just zero a struct, then go on building the unions as needed,
reusing settings from the previous test, i.e. local -> remote, etc.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20170816222156.19953-5-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/mem.c

@@ -0,0 +1,56 @@
+#include "util/mem-events.h"
+#include "util/symbol.h"
+#include "linux/perf_event.h"
+#include "util/debug.h"
+#include "tests.h"
+#include <string.h>
+
+static int check(union perf_mem_data_src data_src,
+		  const char *string)
+{
+	char out[100];
+	char failure[100];
+	struct mem_info mi = { .data_src = data_src };
+
+	int n;
+
+	n = perf_mem__snp_scnprintf(out, sizeof out, &mi);
+	n += perf_mem__lvl_scnprintf(out + n, sizeof out - n, &mi);
+	snprintf(failure, sizeof failure, "unexpected %s", out);
+	TEST_ASSERT_VAL(failure, !strcmp(string, out));
+	return 0;
+}
+
+int test__mem(struct test *text __maybe_unused, int subtest __maybe_unused)
+{
+	int ret = 0;
+	union perf_mem_data_src src;
+
+	memset(&src, 0, sizeof(src));
+
+	src.mem_lvl = PERF_MEM_LVL_HIT;
+	src.mem_lvl_num = 4;
+
+	ret |= check(src, "N/AL4 hit");
+
+	src.mem_remote = 1;
+
+	ret |= check(src, "N/ARemote L4 hit");
+
+	src.mem_lvl = PERF_MEM_LVL_MISS;
+	src.mem_lvl_num = PERF_MEM_LVLNUM_PMEM;
+	src.mem_remote = 0;
+
+	ret |= check(src, "N/APMEM miss");
+
+	src.mem_remote = 1;
+
+	ret |= check(src, "N/ARemote PMEM miss");
+
+	src.mem_snoopx = PERF_MEM_SNOOPX_FWD;
+	src.mem_lvl_num = PERF_MEM_LVLNUM_RAM;
+
+	ret |= check(src , "FwdRemote RAM miss");
+
+	return ret;
+}