regerror.c

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/*
 * regerror - error-code expansion
 *
 * Copyright (c) 1998, 1999 Henry Spencer.  All rights reserved.
 *
 * Development of this software was funded, in part, by Cray Research Inc.,
 * UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics
 * Corporation, none of whom are responsible for the results.  The author
 * thanks all of them.
 *
 * Redistribution and use in source and binary forms -- with or without
 * modification -- are permitted for any purpose, provided that
 * redistributions in source form retain this entire copyright notice and
 * indicate the origin and nature of any modifications.
 *
 * I'd appreciate being given credit for this package in the documentation
 * of software which uses it, but that is not a requirement.
 *
 * THIS SOFTWARE IS PROVIDED ``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
 * HENRY SPENCER 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.
 *
 * src/backend/regex/regerror.c
 *
 */
 
#include "regex/regguts.h"
 
/* unknown-error explanation */
static const char unk[] = "*** unknown regex error code 0x%x ***";
 
/* struct to map among codes, code names, and explanations */
static const struct rerr
{
    int         code;
    const char *name;
    const char *explain;
}           rerrs[] =
 
{
    /* the actual table is built from regex.h */
#include "regex/regerrs.h"
    {
        -1, "", "oops"
    },                          /* explanation special-cased in code */
};
 
/*
 * pg_regerror - the interface to error numbers
 */
/* ARGSUSED */
size_t                          /* actual space needed (including NUL) */
pg_regerror(int errcode,        /* error code, or REG_ATOI or REG_ITOA */
            const regex_t *preg,    /* associated regex_t (unused at present) */
            char *errbuf,       /* result buffer (unless errbuf_size==0) */
            size_t errbuf_size) /* available space in errbuf, can be 0 */
{
    const struct rerr *r;
    const char *msg;
    char        convbuf[sizeof(unk) + 50];  /* 50 = plenty for int */
    size_t      len;
    int         icode;
 
    switch (errcode)
    {
        case REG_ATOI:          /* convert name to number */
            for (r = rerrs; r->code >= 0; r++)
                if (strcmp(r->name, errbuf) == 0)
                    break;
            sprintf(convbuf, "%d", r->code);    /* -1 for unknown */
            msg = convbuf;
            break;
        case REG_ITOA:          /* convert number to name */
            icode = atoi(errbuf);   /* not our problem if this fails */
            for (r = rerrs; r->code >= 0; r++)
                if (r->code == icode)
                    break;
            if (r->code >= 0)
                msg = r->name;
            else
            {                   /* unknown; tell him the number */
                sprintf(convbuf, "REG_%u", (unsigned) icode);
                msg = convbuf;
            }
            break;
        default:                /* a real, normal error code */
            for (r = rerrs; r->code >= 0; r++)
                if (r->code == errcode)
                    break;
            if (r->code >= 0)
                msg = r->explain;
            else
            {                   /* unknown; say so */
                sprintf(convbuf, unk, errcode);
                msg = convbuf;
            }
            break;
    }
 
    len = strlen(msg) + 1;      /* space needed, including NUL */
    if (errbuf_size > 0)
    {
        if (errbuf_size > len)
            strcpy(errbuf, msg);
        else
        {                       /* truncate to fit */
            memcpy(errbuf, msg, errbuf_size - 1);
            errbuf[errbuf_size - 1] = '\0';
        }
    }
 
    return len;
}