[PATCH v2 1/3] perf util: Move block_pair_cmp to block-info

[Jin Yao <yao.jin@linux.intel.com>]

block_pair_cmp() is a function which is used to compare
two blocks. Moving it from builtin-diff.c to block-info.c
to let it be used by other builtins.

In block_pair_cmp, there is a minor change. It checks valid
for map, dso and sym first. If they are invalid, we will not
compare the address because the address might not make sense.

 v2:
 ---
 New patch created in v2

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
---
 tools/perf/builtin-diff.c    | 17 -----------------
 tools/perf/util/block-info.c | 23 +++++++++++++++++++++++
 tools/perf/util/block-info.h |  2 ++
 3 files changed, 25 insertions(+), 17 deletions(-)

diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index f8b6ae557d8b..5ff1e21082cb 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -572,23 +572,6 @@ static void init_block_hist(struct block_hist *bh)
 	bh->valid = true;
 }
 
-static int block_pair_cmp(struct hist_entry *a, struct hist_entry *b)
-{
-	struct block_info *bi_a = a->block_info;
-	struct block_info *bi_b = b->block_info;
-	int cmp;
-
-	if (!bi_a->sym || !bi_b->sym)
-		return -1;
-
-	cmp = strcmp(bi_a->sym->name, bi_b->sym->name);
-
-	if ((!cmp) && (bi_a->start == bi_b->start) && (bi_a->end == bi_b->end))
-		return 0;
-
-	return -1;
-}
-
 static struct hist_entry *get_block_pair(struct hist_entry *he,
 					 struct hists *hists_pair)
 {
diff --git a/tools/perf/util/block-info.c b/tools/perf/util/block-info.c
index c4b030bf6ec2..18a445938681 100644
--- a/tools/perf/util/block-info.c
+++ b/tools/perf/util/block-info.c
@@ -475,3 +475,26 @@ float block_info__total_cycles_percent(struct hist_entry *he)
 
 	return 0.0;
 }
+
+int block_pair_cmp(struct hist_entry *pair, struct hist_entry *he)
+{
+	struct block_info *bi_p = pair->block_info;
+	struct block_info *bi_h = he->block_info;
+	struct map_symbol *ms_p = &pair->ms;
+	struct map_symbol *ms_h = &he->ms;
+	int cmp;
+
+	if (!ms_p->map || !ms_p->map->dso || !ms_p->sym ||
+	    !ms_h->map || !ms_h->map->dso || !ms_h->sym) {
+		return -1;
+	}
+
+	cmp = strcmp(ms_p->sym->name, ms_h->sym->name);
+	if (cmp)
+		return -1;
+
+	if ((bi_p->start == bi_h->start) && (bi_p->end == bi_h->end))
+		return 0;
+
+	return -1;
+}
diff --git a/tools/perf/util/block-info.h b/tools/perf/util/block-info.h
index bef0d75e9819..bfa22c59195d 100644
--- a/tools/perf/util/block-info.h
+++ b/tools/perf/util/block-info.h
@@ -76,4 +76,6 @@ int report__browse_block_hists(struct block_hist *bh, float min_percent,
 
 float block_info__total_cycles_percent(struct hist_entry *he);
 
+int block_pair_cmp(struct hist_entry *pair, struct hist_entry *he);
+
 #endif /* __PERF_BLOCK_H */
-- 
2.17.1