bpf-filter.y

  1%parse-param {struct list_head *expr_head}
  2%define parse.error verbose
  3
  4%{
  5
  6#ifndef NDEBUG
  7#define YYDEBUG 1
  8#endif
  9
 10#include <stdio.h>
 11#include <string.h>
 12#include <linux/compiler.h>
 13#include <linux/list.h>
 14#include "bpf-filter.h"
 15#include "cgroup.h"
 16
 17int perf_bpf_filter_lex(void);
 18
 19/* To indicate if the current term needs a pathname or not */
 20int perf_bpf_filter_needs_path;
 21
 22static void perf_bpf_filter_error(struct list_head *expr __maybe_unused,
 23				  char const *msg)
 24{
 25	printf("perf_bpf_filter: %s\n", msg);
 26}
 27
 28%}
 29
 30%union
 31{
 32	unsigned long num;
 33	char *path;
 34	struct {
 35		enum perf_bpf_filter_term term;
 36		int part;
 37	} sample;
 38	enum perf_bpf_filter_op op;
 39	struct perf_bpf_filter_expr *expr;
 40}
 41
 42%token BFT_SAMPLE BFT_SAMPLE_PATH BFT_OP BFT_ERROR BFT_NUM BFT_LOGICAL_OR BFT_PATH
 43%type <expr> filter_term filter_expr
 44%destructor { free ($$); } <expr>
 45%type <sample> BFT_SAMPLE BFT_SAMPLE_PATH
 46%type <op> BFT_OP
 47%type <num> BFT_NUM
 48%type <path> BFT_PATH
 49
 50%%
 51
 52filter:
 53filter ',' filter_term
 54{
 55	list_add_tail(&$3->list, expr_head);
 56}
 57|
 58filter_term
 59{
 60	list_add_tail(&$1->list, expr_head);
 61}
 62
 63filter_term:
 64filter_term BFT_LOGICAL_OR filter_expr
 65{
 66	struct perf_bpf_filter_expr *expr;
 67
 68	if ($1->op == PBF_OP_GROUP_BEGIN) {
 69		expr = $1;
 70	} else {
 71		expr = perf_bpf_filter_expr__new(PBF_TERM_NONE, /*part=*/0,
 72						 PBF_OP_GROUP_BEGIN, /*val=*/1);
 73		list_add_tail(&$1->list, &expr->groups);
 74	}
 75	expr->val++;
 76	list_add_tail(&$3->list, &expr->groups);
 77	$$ = expr;
 78}
 79|
 80filter_expr
 81{
 82	$$ = $1;
 83}
 84
 85filter_expr:
 86BFT_SAMPLE BFT_OP BFT_NUM
 87{
 88	$$ = perf_bpf_filter_expr__new($1.term, $1.part, $2, $3);
 89}
 90|
 91BFT_SAMPLE_PATH BFT_OP BFT_PATH
 92{
 93	struct cgroup *cgrp;
 94	unsigned long cgroup_id = 0;
 95
 96	if ($2 != PBF_OP_EQ && $2 != PBF_OP_NEQ) {
 97		printf("perf_bpf_filter: cgroup accepts '==' or '!=' only\n");
 98		YYERROR;
 99	}
100
101	cgrp = cgroup__new($3, /*do_open=*/false);
102	if (cgrp && read_cgroup_id(cgrp) == 0)
103		cgroup_id = cgrp->id;
104
105	$$ = perf_bpf_filter_expr__new($1.term, $1.part, $2, cgroup_id);
106	cgroup__put(cgrp);
107}
108
109%%