[PATCH v8 2/8] perf metric: Use NAN for missing event IDs.

[Ian Rogers <irogers@google.com>]

If during computing a metric an event (id) is missing the parsing
aborts. A later patch will make it so that events that aren't used in
the output are deliberately omitted, in which case we don't want the
abort. Modify the missing ID case to report NAN for these cases.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/expr.y | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y
index b2ada8f8309a..41c9cd4efadd 100644
--- a/tools/perf/util/expr.y
+++ b/tools/perf/util/expr.y
@@ -1,6 +1,7 @@
 /* Simple expression parser */
 %{
 #define YYDEBUG 1
+#include <math.h>
 #include <stdio.h>
 #include "util.h"
 #include "util/debug.h"
@@ -88,12 +89,10 @@ expr:	  NUMBER
 	| ID			{
 					struct expr_id_data *data;
 
-					if (expr__resolve_id(ctx, $1, &data)) {
-						free($1);
-						YYABORT;
-					}
+					$$ = NAN;
+					if (expr__resolve_id(ctx, $1, &data) == 0)
+						$$ = expr_id_data__value(data);
 
-					$$ = expr_id_data__value(data);
 					free($1);
 				}
 	| expr '|' expr		{ $$ = (long)$1 | (long)$3; }
-- 
2.33.0.464.g1972c5931b-goog