[RFC 03/12] perf event action: Add parsing const integer expr support

Yang Jihong
2024-11-28T13:36:30Z

Support parsing of constant integer expression.

Signed-off-by: Yang Jihong <yangjihong@bytedance.com>
---
tools/perf/util/parse-action.c | 52 ++++++++++++++++++++++++++++++++++
tools/perf/util/parse-action.h | 1 +
tools/perf/util/parse-action.l | 19 +++++++++++++
tools/perf/util/parse-action.y | 13 ++++++++-
4 files changed, 84 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/parse-action.c b/tools/perf/util/parse-action.c
index 391546bf3d73..3b10cf9f99b3 100644
--- a/tools/perf/util/parse-action.c
+++ b/tools/perf/util/parse-action.c
@@ -7,6 +7,7 @@
*
* Supported expressions:
* - constant:
+ * - integer
*/

#include "util/debug.h"
@@ -118,7 +119,58 @@ void event_actions__free(void)
(void)event_actions__for_each_expr_safe(do_action_free, NULL, false);
}

+static int expr_const_int_new(struct evtact_expr *expr, void *data, int size)
+{
+ if (data == NULL ||
+ (size != sizeof(int)
+ && size != sizeof(long) && size != sizeof(long long))) {
+ pr_err("expr_const_int size invalid: %d\n", size);
+ return -EINVAL;
+ }
+
+ expr->priv = malloc(sizeof(long long));
+ if (expr->priv == NULL) {
+ pr_err("exp_ const_int malloc failed\n");
+ return -ENOMEM;
+ }
+
+ if (size == sizeof(int))
+ *(unsigned long long *)(expr->priv) = *(unsigned int *)data;
+ else if (size == sizeof(long))
+ *(unsigned long long *)(expr->priv) = *(unsigned long *)data;
+ else if (size == sizeof(long long))
+ *(unsigned long long *)(expr->priv) = *(unsigned long long *)data;
+
+ INIT_LIST_HEAD(&expr->opnds);
+ return 0;
+}
+
+static void expr_const_int_free(struct evtact_expr *expr)
+{
+ zfree(&expr->priv);
+}
+
+static int expr_const_int_eval(struct evtact_expr *expr,
+ void *in __maybe_unused, int in_size __maybe_unused,
+ void **out, int *out_size)
+{
+ if (out != NULL)
+ *out = expr->priv;
+
+ if (out_size != NULL)
+ *out_size = sizeof(long long);
+
+ return 0;
+}
+
+static struct evtact_expr_ops expr_const_int_ops = {
+ .new = expr_const_int_new,
+ .free = expr_const_int_free,
+ .eval = expr_const_int_eval,
+};
+
static struct evtact_expr_ops *expr_const_ops_list[EVTACT_EXPR_CONST_TYPE_MAX] = {
+ [EVTACT_EXPR_CONST_TYPE_INT] = &expr_const_int_ops,
};

static int expr_const_set_ops(struct evtact_expr *expr, u32 opcode)
diff --git a/tools/perf/util/parse-action.h b/tools/perf/util/parse-action.h
index 47bd75264dee..ac81278c590e 100644
--- a/tools/perf/util/parse-action.h
+++ b/tools/perf/util/parse-action.h
@@ -14,6 +14,7 @@ enum evtact_expr_type {
};

enum evtact_expr_const_type {
+ EVTACT_EXPR_CONST_TYPE_INT,
EVTACT_EXPR_CONST_TYPE_MAX,
};

diff --git a/tools/perf/util/parse-action.l b/tools/perf/util/parse-action.l
index 3cb72de50372..9237399a11ac 100644
--- a/tools/perf/util/parse-action.l
+++ b/tools/perf/util/parse-action.l
@@ -13,13 +13,32 @@
#include "parse-action.h"
#include "parse-action-bison.h"

+static int value(int base)
+{
+ unsigned long long num;
+
+ errno = 0;
+ num = strtoul(parse_action_text, NULL, base);
+ if (errno) {
+ pr_err("parse_action malloc number failed\n");
+ return ERROR;
+ }
+
+ parse_action_lval.num = num;
+ return NUMBER;
+}
+
%}

+num_dec [0-9]+
+num_hex 0[xX][0-9a-fA-F]+
space [ \t]
ident [_a-zA-Z][_a-zA-Z0-9]*

%%

+{num_dec} { return value(10); }
+{num_hex} { return value(16); }
{space} { }

";" { return SEMI; }
diff --git a/tools/perf/util/parse-action.y b/tools/perf/util/parse-action.y
index fade9d093d4a..51e77e54f157 100644
--- a/tools/perf/util/parse-action.y
+++ b/tools/perf/util/parse-action.y
@@ -17,6 +17,8 @@
#include "util/debug.h"
#include "util/parse-action.h"

+#define expr_id(t, o) evtact_expr_id_encode(EVTACT_EXPR_TYPE_##t, EVTACT_EXPR_##t##_TYPE_##o)
+
int parse_action_lex(void);

static void parse_action_error(struct list_head *expr __maybe_unused,
@@ -32,13 +34,15 @@ static void parse_action_error(struct list_head *expr __maybe_unused,
char *str;
struct evtact_expr *expr;
struct list_head *list;
+ unsigned long long num;
}

-%token IDENT ERROR
+%token IDENT ERROR NUMBER
%token SEMI
%type <expr> action_term expr_term
%destructor { parse_action_expr__free($$); } <expr>
%type <str> IDENT
+%type <num> NUMBER

%%

@@ -65,6 +69,13 @@ expr_term
}

expr_term:
+NUMBER
+{
+ $$ = parse_action_expr__new(expr_id(CONST, INT), NULL, (void *)&$1, sizeof($1));
+ if ($$ == NULL)
+ YYERROR;
+}
+|
IDENT
{
$$ = NULL;
--
2.25.1