gen_packed_field_checks.c

 1// SPDX-License-Identifier: GPL-2.0
 2// Copyright (c) 2024, Intel Corporation
 3#include <stdbool.h>
 4#include <stdio.h>
 5
 6#define MAX_PACKED_FIELD_SIZE 50
 7
 8int main(int argc, char **argv)
 9{
10	/* The first macro doesn't need a 'do {} while(0)' loop */
11	printf("#define CHECK_PACKED_FIELDS_1(fields) \\\n");
12	printf("\tCHECK_PACKED_FIELD(fields, 0)\n\n");
13
14	/* Remaining macros require a do/while loop, and are implemented
15	 * recursively by calling the previous iteration's macro.
16	 */
17	for (int i = 2; i <= MAX_PACKED_FIELD_SIZE; i++) {
18		printf("#define CHECK_PACKED_FIELDS_%d(fields) do { \\\n", i);
19		printf("\tCHECK_PACKED_FIELDS_%d(fields); \\\n", i - 1);
20		printf("\tCHECK_PACKED_FIELD(fields, %d); \\\n", i - 1);
21		printf("} while (0)\n\n");
22	}
23
24	printf("#define CHECK_PACKED_FIELDS(fields) \\\n");
25
26	for (int i = 1; i <= MAX_PACKED_FIELD_SIZE; i++)
27		printf("\t__builtin_choose_expr(ARRAY_SIZE(fields) == %d, ({ CHECK_PACKED_FIELDS_%d(fields); }), \\\n",
28		       i, i);
29
30	printf("\t({ BUILD_BUG_ON_MSG(1, \"CHECK_PACKED_FIELDS() must be regenerated to support array sizes larger than %d.\"); }) \\\n",
31	       MAX_PACKED_FIELD_SIZE);
32
33	for (int i = 1; i <= MAX_PACKED_FIELD_SIZE; i++)
34		printf(")");
35
36	printf("\n");
37}