c - MISRA C :2012: Rule 4. 1 八进制和十六进制转义序列应终止

Question

我在 C 中有以下代码，违反了 MISRAC:2012 规则 4.1(即八进制和十六进制转义序列应终止)。我不清楚哪个是解决以下代码的正确合规解决方案。

static const char rcsid[] = "\n@(#) $Revision: 243501 $\n";

和

rerrs[] = {
    { REG_NOMATCH,  "REG_NOMATCH",  "llvm_regexec() failed to match" },
    { REG_BADPAT,   "REG_BADPAT",   "invalid regular expression" },
    { REG_ECOLLATE, "REG_ECOLLATE", "invalid collating element" },
    { REG_ECTYPE,   "REG_ECTYPE",   "invalid character class" },
    { REG_EESCAPE,  "REG_EESCAPE",  "trailing backslash (\\)" },
    { REG_ESUBREG,  "REG_ESUBREG",  "invalid backreference number" },
    { REG_EBRACK,   "REG_EBRACK",   "brackets ([ ]) not balanced" },
    { REG_EPAREN,   "REG_EPAREN",   "parentheses not balanced" },
    { REG_EBRACE,   "REG_EBRACE",   "braces not balanced" },
    { REG_BADBR,    "REG_BADBR",    "invalid repetition count(s)" },
    { REG_ERANGE,   "REG_ERANGE",   "invalid character range" },
    { REG_ESPACE,   "REG_ESPACE",   "out of memory" },
    { REG_BADRPT,   "REG_BADRPT",   "repetition-operator operand invalid" },
    { REG_EMPTY,    "REG_EMPTY",    "empty (sub)expression" },
    { REG_ASSERT,   "REG_ASSERT",   "\"can't happen\" -- you found a bug" },
    { REG_INVARG,   "REG_INVARG",   "invalid argument to regex routine" },
    { 0,        "",     "*** unknown regexp error code ***" }
};

关于这个，Understand tool of Scitool 说违规在第 58 行:

第二次违规的所有代码是

*-
 * This code is derived from OpenBSD's libc/regex, original license follows:
 *
 * Copyright (c) 1992, 1993, 1994 Henry Spencer.
 * Copyright (c) 1992, 1993, 1994
 *  The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Henry Spencer.
 *
 * 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 *  @(#)regerror.c  8.4 (Berkeley) 3/20/94
 */

#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <limits.h>
#include <stdlib.h>
#include "regex_impl.h"

#include "regutils.h"

#ifdef _MSC_VER
#define snprintf _snprintf
#endif

static const char *regatoi(const llvm_regex_t *, char *, int);

static struct rerr {
    int code;
    const char *name;
    const char *explain;
} rerrs[] = {
    { REG_NOMATCH,  "REG_NOMATCH",  "llvm_regexec() failed to match" },
    { REG_BADPAT,   "REG_BADPAT",   "invalid regular expression" },
    { REG_ECOLLATE, "REG_ECOLLATE", "invalid collating element" },
    { REG_ECTYPE,   "REG_ECTYPE",   "invalid character class" },
    { REG_EESCAPE,  "REG_EESCAPE",  "trailing backslash (\\)" },
    { REG_ESUBREG,  "REG_ESUBREG",  "invalid backreference number" },
    { REG_EBRACK,   "REG_EBRACK",   "brackets ([ ]) not balanced" },
    { REG_EPAREN,   "REG_EPAREN",   "parentheses not balanced" },
    { REG_EBRACE,   "REG_EBRACE",   "braces not balanced" },
    { REG_BADBR,    "REG_BADBR",    "invalid repetition count(s)" },
    { REG_ERANGE,   "REG_ERANGE",   "invalid character range" },
    { REG_ESPACE,   "REG_ESPACE",   "out of memory" },
    { REG_BADRPT,   "REG_BADRPT",   "repetition-operator operand invalid" },
    { REG_EMPTY,    "REG_EMPTY",    "empty (sub)expression" },
    { REG_ASSERT,   "REG_ASSERT",   "\"can't happen\" -- you found a bug" },
    { REG_INVARG,   "REG_INVARG",   "invalid argument to regex routine" },
    { 0,        "",     "*** unknown regexp error code ***" }
};

/*
 - llvm_regerror - the interface to error numbers
 = extern size_t llvm_regerror(int, const llvm_regex_t *, char *, size_t);
 */
/* ARGSUSED */
size_t
llvm_regerror(int errcode, const llvm_regex_t *preg, char *errbuf, size_t errbuf_size)
{
    struct rerr *r;
    size_t len;
    int target = errcode &~ REG_ITOA;
    const char *s;
    char convbuf[50];

    if (errcode == REG_ATOI)
        s = regatoi(preg, convbuf, sizeof convbuf);
    else {
        for (r = rerrs; r->code != 0; r++)
            if (r->code == target)
                break;

        if (errcode&REG_ITOA) {
            if (r->code != 0) {
                assert(strlen(r->name) < sizeof(convbuf));
                (void) llvm_strlcpy(convbuf, r->name, sizeof convbuf);
            } else
                (void)snprintf(convbuf, sizeof convbuf,
                    "REG_0x%x", target);
            s = convbuf;
        } else
            s = r->explain;
    }

    len = strlen(s) + 1;
    if (errbuf_size > 0) {
        llvm_strlcpy(errbuf, s, errbuf_size);
    }

    return(len);
}

/*
 - regatoi - internal routine to implement REG_ATOI
 */
static const char *
regatoi(const llvm_regex_t *preg, char *localbuf, int localbufsize)
{
    struct rerr *r;

    for (r = rerrs; r->code != 0; r++)
        if (strcmp(r->name, preg->re_endp) == 0)
            break;
    if (r->code == 0)
        return("0");

    (void)snprintf(localbuf, localbufsize, "%d", r->code);
    return(localbuf);
}

Answer 1

发布的代码中没有八进制/十六进制转义序列，因此您的静态分析器是错误的。

\n、\" 和 \\ 是“简单的转义序列”，MISRA-C 对此无话可说。

行 static const char rcsid[] = "\n@(#) $Revision: 243501 $\n"; 符合 MISRA-C。