Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Fri, 17 Sep 2021 23:35:07 -0700
In-Reply-To: <20210918063513.2356923-1-irogers@google.com>
Message-Id: <20210918063513.2356923-3-irogers@google.com>
Mime-Version: 1.0
References: <20210918063513.2356923-1-irogers@google.com>
Subject: [PATCH v8 2/8] perf metric: Use NAN for missing event IDs.
From:   Ian Rogers <irogers@google.com>
To:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>,
        linux-kernel@vger.kernel.org, Andi Kleen <ak@linux.intel.com>,
        Jin Yao <yao.jin@linux.intel.com>,
        John Garry <john.garry@huawei.com>,
        Paul Clarke <pc@us.ibm.com>, kajoljain <kjain@linux.ibm.com>,
        linux-perf-users@vger.kernel.org
Cc:     Stephane Eranian <eranian@google.com>,
        Sandeep Dasgupta <sdasgup@google.com>,
        Ian Rogers <irogers@google.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

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