[PATCH 12/18] perf metric: Compute referenced metrics

[Jiri Olsa]

Adding computation (expr__parse call) of referenced metric at
the point when it needs to be resolved during the 'master'
metric computation.

Once the inner metric is computed, the result is stored and
used if there's another usage of that metric.

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
 tools/perf/util/expr.c | 31 +++++++++++++++++++++++++++++++
 tools/perf/util/expr.h |  3 +++
 tools/perf/util/expr.y |  4 ++--
 3 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
index 6bf8a21f5c53..2784df38f8c2 100644
--- a/tools/perf/util/expr.c
+++ b/tools/perf/util/expr.c
@@ -91,6 +91,7 @@ int expr__add_ref(struct expr_parse_ctx *ctx, struct metric_ref *ref)
 
 	data_ptr->ref.metric_name = ref->metric_name;
 	data_ptr->ref.metric_expr = ref->metric_expr;
+	data_ptr->ref.counted = false;
 	data_ptr->is_ref = true;
 
 	ret = hashmap__set(&ctx->ids, name, data_ptr,
@@ -110,6 +111,34 @@ int expr__get_id(struct expr_parse_ctx *ctx, const char *id,
 	return hashmap__find(&ctx->ids, id, (void **)data) ? 0 : -1;
 }
 
+int expr__resolve_id(struct expr_parse_ctx *ctx, const char *id,
+		     struct expr_id_data **datap)
+{
+	struct expr_id_data *data;
+
+	if (expr__get_id(ctx, id, datap) || !*datap) {
+		pr_debug("%s not found\n", id);
+		return -1;
+	}
+
+	data = *datap;
+
+	pr_debug2("lookup: is_ref %d, counted %d, val %f: %s\n",
+		  data->is_ref, data->ref.counted, data->val, id);
+
+	if (data->is_ref && !data->ref.counted) {
+		data->ref.counted = true;
+		pr_debug("processing metric: %s ENTRY\n", id);
+		if (expr__parse(&data->val, ctx, data->ref.metric_expr, 1)) {
+			pr_debug("%s failed to count\n", id);
+			return -1;
+		}
+		pr_debug("processing metric: %s EXIT: %f\n", id, data->val);
+	}
+
+	return 0;
+}
+
 void expr__del_id(struct expr_parse_ctx *ctx, const char *id)
 {
 	struct expr_id_data *old_val = NULL;
@@ -150,6 +179,8 @@ __expr__parse(double *val, struct expr_parse_ctx *ctx, const char *expr,
 	void *scanner;
 	int ret;
 
+	pr_debug2("parsing metric: %s\n", expr);
+
 	ret = expr_lex_init_extra(&scanner_ctx, &scanner);
 	if (ret)
 		return ret;
diff --git a/tools/perf/util/expr.h b/tools/perf/util/expr.h
index d19e66915228..b6d1fba64eaa 100644
--- a/tools/perf/util/expr.h
+++ b/tools/perf/util/expr.h
@@ -25,6 +25,7 @@ struct expr_id_data {
 		struct {
 			const char *metric_name;
 			const char *metric_expr;
+			bool counted;
 		} ref;
 	};
 };
@@ -42,6 +43,8 @@ int expr__add_id_val(struct expr_parse_ctx *ctx, const char *id, double val);
 int expr__add_ref(struct expr_parse_ctx *ctx, struct metric_ref *ref);
 int expr__get_id(struct expr_parse_ctx *ctx, const char *id,
 		 struct expr_id_data **data);
+int expr__resolve_id(struct expr_parse_ctx *ctx, const char *id,
+		     struct expr_id_data **datap);
 int expr__parse(double *final_val, struct expr_parse_ctx *ctx,
 		const char *expr, int runtime);
 int expr__find_other(const char *expr, const char *one,
diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y
index 0d4f5d324be7..d34b370391c6 100644
--- a/tools/perf/util/expr.y
+++ b/tools/perf/util/expr.y
@@ -88,11 +88,11 @@ expr:	  NUMBER
 	| ID			{
 					struct expr_id_data *data;
 
-					if (expr__get_id(ctx, $1, &data) || !data) {
-						pr_debug("%s not found\n", $1);
+					if (expr__resolve_id(ctx, $1, &data)) {
 						free($1);
 						YYABORT;
 					}
+
 					$$ = data->val;
 					free($1);
 				}
-- 
2.25.4