perf metric: Change expr__get_id to return struct expr_id_data

Changing expr__get_id to use and return struct expr_id_data
pointer as value for the ID. This way we can access data other
than value for given ID in following changes.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Reviewed-by: Kajol Jain <kjain@linux.ibm.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200719181320.785305-4-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/expr.c

@@ -73,14 +73,10 @@ int expr__add_id_val(struct expr_parse_ctx *ctx, const char *id, double val)
 	return ret;
 }
 
-int expr__get_id(struct expr_parse_ctx *ctx, const char *id, double *val_ptr)
+int expr__get_id(struct expr_parse_ctx *ctx, const char *id,
+		 struct expr_id_data **data)
 {
-	struct expr_id_data *data;
-
-	if (!hashmap__find(&ctx->ids, id, (void **)&data))
-		return -1;
-	*val_ptr = (data == NULL) ?  0.0 : data->val;
-	return 0;
+	return hashmap__find(&ctx->ids, id, (void **)data) ? 0 : -1;
 }
 
 void expr__ctx_init(struct expr_parse_ctx *ctx)

tools/perf/util/expr.h

@@ -28,7 +28,8 @@ void expr__ctx_init(struct expr_parse_ctx *ctx);
 void expr__ctx_clear(struct expr_parse_ctx *ctx);
 int expr__add_id(struct expr_parse_ctx *ctx, const char *id);
 int expr__add_id_val(struct expr_parse_ctx *ctx, const char *id, double val);
-int expr__get_id(struct expr_parse_ctx *ctx, const char *id, double *val_ptr);
+int expr__get_id(struct expr_parse_ctx *ctx, const char *id,
+		 struct expr_id_data **data);
 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,

tools/perf/util/expr.y

@@ -85,12 +85,16 @@ if_expr:
 	;
 
 expr:	  NUMBER
-	| ID			{ if (expr__get_id(ctx, $1, &$$)) {
-					pr_debug("%s not found\n", $1);
+	| ID			{
+					struct expr_id_data *data;
+
+					if (expr__get_id(ctx, $1, &data) || !data) {
+						pr_debug("%s not found\n", $1);
+						free($1);
+						YYABORT;
+					}
+					$$ = data->val;
 					free($1);
-					YYABORT;
-				  }
-				  free($1);
 				}
 	| expr '|' expr		{ $$ = (long)$1 | (long)$3; }
 	| expr '&' expr		{ $$ = (long)$1 & (long)$3; }