/*      $NetBSD: h_ctype_abuse.c,v 1.2 2025/09/15 17:32:01 riastradh Exp $      */

/*-
 * Copyright (c) 2025 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Helper program to verify effects of ctype(3) abuse.
 *
 * NOTE: This program intentionally triggers undefined behaviour by
 * passing int values to the ctype(3) functions which are neither EOF
 * nor representable by unsigned char.  The purpose is to verify that
 * NetBSD's ctype(3) _does not_ trap the undefined behaviour when the
 * environment variable LIBC_ALLOWCTYPEABUSE.  (It does not check
 * anything about the results, which are perforce nonsense -- just that
 * it gets a result without crashing.)
 */

#include <sys/cdefs.h>
__RCSID("$NetBSD: h_ctype_abuse.c,v 1.2 2025/09/15 17:32:01 riastradh Exp $");

#include <ctype.h>
#include <err.h>
#include <limits.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define FOREACHCTYPE(M)                                                       \
        M(ISALPHA, isalpha)                                                   \
        M(ISUPPER, isupper)                                                   \
        M(ISLOWER, islower)                                                   \
        M(ISDIGIT, isdigit)                                                   \
        M(ISXDIGIT, isxdigit)                                                 \
        M(ISALNUM, isalnum)                                                   \
        M(ISSPACE, isspace)                                                   \
        M(ISPUNCT, ispunct)                                                   \
        M(ISPRINT, isprint)                                                   \
        M(ISGRAPH, isgraph)                                                   \
        M(ISCNTRL, iscntrl)                                                   \
        M(ISBLANK, isblank)                                                   \
        M(TOUPPER, toupper)                                                   \
        M(TOLOWER, tolower)

int
main(int argc, char **argv)
{
        enum {
#define M(upper, lower) upper,
                FOREACHCTYPE(M)
#undef M
        } fn;
        enum {
                MACRO,
                FUNCTION,
        } mode;
        int ch;
        volatile int result;

        setprogname(argv[0]);
        if (argc != 3 && argc != 4) {
                errx(1, "Usage: %s <function> <mode> [<locale>]",
                    getprogname());
        }

#define M(upper, lower)                                                       \
        else if (strcmp(argv[1], #lower) == 0)                                \
                fn = upper;

        if (0)
                ;
        FOREACHCTYPE(M)
        else
                errx(1, "unknown ctype function");
#undef M

        if (strcmp(argv[2], "macro") == 0)
                mode = MACRO;
        else if (strcmp(argv[2], "function") == 0)
                mode = FUNCTION;
        else
                errx(1, "unknown usage mode");

        if (argc == 4) {
                if (setlocale(LC_CTYPE, argv[3]) == NULL)
                        err(1, "setlocale");
        }

        /*
         * Make sure we cover EOF as well.
         */
        __CTASSERT(CHAR_MIN == 0 || CHAR_MIN <= EOF);
        __CTASSERT(EOF <= UCHAR_MAX);

        for (ch = (CHAR_MIN == 0 ? EOF : CHAR_MIN); ch <= UCHAR_MAX; ch++) {
                switch (fn) {
#define M(upper, lower)                                                       \
                case upper:                                                   \
                        switch (mode) {                                       \
                        case MACRO:                                           \
                                result = lower(ch);                           \
                                break;                                        \
                        case FUNCTION:                                        \
                                result = (lower)(ch);                         \
                                break;                                        \
                        }                                                     \
                        break;
                FOREACHCTYPE(M)
#undef M
                }
                (void)result;
        }

        return 0;
}