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kc3-lang/libbsd/src/unvis.c

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  • Author : Guillem Jover
    Date : 2024-01-08 23:37:43
    Hash : 304a1f83
    Message : doc: Use macOS to refer to the operating system This is the correct spelling, instead of capitalizing it.

  • src/unvis.c
  • /*	$NetBSD: unvis.c,v 1.44 2014/09/26 15:43:36 roy Exp $	*/
    
    /*-
     * Copyright (c) 1989, 1993
     *	The Regents of the University of California.  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.
     * 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.
     */
    
    #include <sys/cdefs.h>
    #include <sys/types.h>
    
    #include <assert.h>
    #include <ctype.h>
    #include <stdint.h>
    #include <stdio.h>
    #include <errno.h>
    #pragma GCC diagnostic push
    #pragma GCC diagnostic ignored "-Wcpp"
    #include <vis.h>
    #pragma GCC diagnostic pop
    
    #include "local-link.h"
    
    #ifdef __weak_alias
    __weak_alias(strnunvisx,_strnunvisx)
    #endif
    
    #define _DIAGASSERT(x)
    
    /*
     * decode driven by state machine
     */
    #define	S_GROUND	0	/* haven't seen escape char */
    #define	S_START		1	/* start decoding special sequence */
    #define	S_META		2	/* metachar started (M) */
    #define	S_META1		3	/* metachar more, regular char (-) */
    #define	S_CTRL		4	/* control char started (^) */
    #define	S_OCTAL2	5	/* octal digit 2 */
    #define	S_OCTAL3	6	/* octal digit 3 */
    #define	S_HEX		7	/* mandatory hex digit */
    #define	S_HEX1		8	/* http hex digit */
    #define	S_HEX2		9	/* http hex digit 2 */
    #define	S_MIME1		10	/* mime hex digit 1 */
    #define	S_MIME2		11	/* mime hex digit 2 */
    #define	S_EATCRNL	12	/* mime eating CRNL */
    #define	S_AMP		13	/* seen & */
    #define	S_NUMBER	14	/* collecting number */
    #define	S_STRING	15	/* collecting string */
    
    #define	isoctal(c) \
    	(((unsigned char)(c)) >= '0' && ((unsigned char)(c)) <= '7')
    #define	xtod(c)		(isdigit(c) ? (c - '0') : ((tolower(c) - 'a') + 10))
    #define	XTOD(c)		(isdigit(c) ? (c - '0') : ((c - 'A') + 10))
    
    /*
     * RFC 1866
     */
    static const struct nv {
    	char name[7];
    	uint8_t value;
    } nv[] = {
    	{ "AElig",	198 }, /* capital AE diphthong (ligature)  */
    	{ "Aacute",	193 }, /* capital A, acute accent  */
    	{ "Acirc",	194 }, /* capital A, circumflex accent  */
    	{ "Agrave",	192 }, /* capital A, grave accent  */
    	{ "Aring",	197 }, /* capital A, ring  */
    	{ "Atilde",	195 }, /* capital A, tilde  */
    	{ "Auml",	196 }, /* capital A, dieresis or umlaut mark  */
    	{ "Ccedil",	199 }, /* capital C, cedilla  */
    	{ "ETH",	208 }, /* capital Eth, Icelandic  */
    	{ "Eacute",	201 }, /* capital E, acute accent  */
    	{ "Ecirc",	202 }, /* capital E, circumflex accent  */
    	{ "Egrave",	200 }, /* capital E, grave accent  */
    	{ "Euml",	203 }, /* capital E, dieresis or umlaut mark  */
    	{ "Iacute",	205 }, /* capital I, acute accent  */
    	{ "Icirc",	206 }, /* capital I, circumflex accent  */
    	{ "Igrave",	204 }, /* capital I, grave accent  */
    	{ "Iuml",	207 }, /* capital I, dieresis or umlaut mark  */
    	{ "Ntilde",	209 }, /* capital N, tilde  */
    	{ "Oacute",	211 }, /* capital O, acute accent  */
    	{ "Ocirc",	212 }, /* capital O, circumflex accent  */
    	{ "Ograve",	210 }, /* capital O, grave accent  */
    	{ "Oslash",	216 }, /* capital O, slash  */
    	{ "Otilde",	213 }, /* capital O, tilde  */
    	{ "Ouml",	214 }, /* capital O, dieresis or umlaut mark  */
    	{ "THORN",	222 }, /* capital THORN, Icelandic  */
    	{ "Uacute",	218 }, /* capital U, acute accent  */
    	{ "Ucirc",	219 }, /* capital U, circumflex accent  */
    	{ "Ugrave",	217 }, /* capital U, grave accent  */
    	{ "Uuml",	220 }, /* capital U, dieresis or umlaut mark  */
    	{ "Yacute",	221 }, /* capital Y, acute accent  */
    	{ "aacute",	225 }, /* small a, acute accent  */
    	{ "acirc",	226 }, /* small a, circumflex accent  */
    	{ "acute",	180 }, /* acute accent  */
    	{ "aelig",	230 }, /* small ae diphthong (ligature)  */
    	{ "agrave",	224 }, /* small a, grave accent  */
    	{ "amp",	 38 }, /* ampersand  */
    	{ "aring",	229 }, /* small a, ring  */
    	{ "atilde",	227 }, /* small a, tilde  */
    	{ "auml",	228 }, /* small a, dieresis or umlaut mark  */
    	{ "brvbar",	166 }, /* broken (vertical) bar  */
    	{ "ccedil",	231 }, /* small c, cedilla  */
    	{ "cedil",	184 }, /* cedilla  */
    	{ "cent",	162 }, /* cent sign  */
    	{ "copy",	169 }, /* copyright sign  */
    	{ "curren",	164 }, /* general currency sign  */
    	{ "deg",	176 }, /* degree sign  */
    	{ "divide",	247 }, /* divide sign  */
    	{ "eacute",	233 }, /* small e, acute accent  */
    	{ "ecirc",	234 }, /* small e, circumflex accent  */
    	{ "egrave",	232 }, /* small e, grave accent  */
    	{ "eth",	240 }, /* small eth, Icelandic  */
    	{ "euml",	235 }, /* small e, dieresis or umlaut mark  */
    	{ "frac12",	189 }, /* fraction one-half  */
    	{ "frac14",	188 }, /* fraction one-quarter  */
    	{ "frac34",	190 }, /* fraction three-quarters  */
    	{ "gt",		 62 }, /* greater than  */
    	{ "iacute",	237 }, /* small i, acute accent  */
    	{ "icirc",	238 }, /* small i, circumflex accent  */
    	{ "iexcl",	161 }, /* inverted exclamation mark  */
    	{ "igrave",	236 }, /* small i, grave accent  */
    	{ "iquest",	191 }, /* inverted question mark  */
    	{ "iuml",	239 }, /* small i, dieresis or umlaut mark  */
    	{ "laquo",	171 }, /* angle quotation mark, left  */
    	{ "lt",		 60 }, /* less than  */
    	{ "macr",	175 }, /* macron  */
    	{ "micro",	181 }, /* micro sign  */
    	{ "middot",	183 }, /* middle dot  */
    	{ "nbsp",	160 }, /* no-break space  */
    	{ "not",	172 }, /* not sign  */
    	{ "ntilde",	241 }, /* small n, tilde  */
    	{ "oacute",	243 }, /* small o, acute accent  */
    	{ "ocirc",	244 }, /* small o, circumflex accent  */
    	{ "ograve",	242 }, /* small o, grave accent  */
    	{ "ordf",	170 }, /* ordinal indicator, feminine  */
    	{ "ordm",	186 }, /* ordinal indicator, masculine  */
    	{ "oslash",	248 }, /* small o, slash  */
    	{ "otilde",	245 }, /* small o, tilde  */
    	{ "ouml",	246 }, /* small o, dieresis or umlaut mark  */
    	{ "para",	182 }, /* pilcrow (paragraph sign)  */
    	{ "plusmn",	177 }, /* plus-or-minus sign  */
    	{ "pound",	163 }, /* pound sterling sign  */
    	{ "quot",	 34 }, /* double quote  */
    	{ "raquo",	187 }, /* angle quotation mark, right  */
    	{ "reg",	174 }, /* registered sign  */
    	{ "sect",	167 }, /* section sign  */
    	{ "shy",	173 }, /* soft hyphen  */
    	{ "sup1",	185 }, /* superscript one  */
    	{ "sup2",	178 }, /* superscript two  */
    	{ "sup3",	179 }, /* superscript three  */
    	{ "szlig",	223 }, /* small sharp s, German (sz ligature)  */
    	{ "thorn",	254 }, /* small thorn, Icelandic  */
    	{ "times",	215 }, /* multiply sign  */
    	{ "uacute",	250 }, /* small u, acute accent  */
    	{ "ucirc",	251 }, /* small u, circumflex accent  */
    	{ "ugrave",	249 }, /* small u, grave accent  */
    	{ "uml",	168 }, /* umlaut (dieresis)  */
    	{ "uuml",	252 }, /* small u, dieresis or umlaut mark  */
    	{ "yacute",	253 }, /* small y, acute accent  */
    	{ "yen",	165 }, /* yen sign  */
    	{ "yuml",	255 }, /* small y, dieresis or umlaut mark  */
    };
    
    /*
     * unvis - decode characters previously encoded by vis
     */
    int
    unvis(char *cp, int c, int *astate, int flag)
    {
    	unsigned char uc = (unsigned char)c;
    	unsigned char st, ia, is, lc;
    
    /*
     * Bottom 8 bits of astate hold the state machine state.
     * Top 8 bits hold the current character in the http 1866 nv string decoding
     */
    #define GS(a)		((a) & 0xff)
    #define SS(a, b)	(((uint32_t)(a) << 24) | (b))
    #define GI(a)		((uint32_t)(a) >> 24)
    
    	_DIAGASSERT(cp != NULL);
    	_DIAGASSERT(astate != NULL);
    	st = GS(*astate);
    
    	if (flag & UNVIS_END) {
    		switch (st) {
    		case S_OCTAL2:
    		case S_OCTAL3:
    		case S_HEX2:
    			*astate = SS(0, S_GROUND);
    			return UNVIS_VALID;
    		case S_GROUND:
    			return UNVIS_NOCHAR;
    		default:
    			return UNVIS_SYNBAD;
    		}
    	}
    
    	switch (st) {
    
    	case S_GROUND:
    		*cp = 0;
    		if ((flag & VIS_NOESCAPE) == 0 && c == '\\') {
    			*astate = SS(0, S_START);
    			return UNVIS_NOCHAR;
    		}
    		if ((flag & VIS_HTTP1808) && c == '%') {
    			*astate = SS(0, S_HEX1);
    			return UNVIS_NOCHAR;
    		}
    		if ((flag & VIS_HTTP1866) && c == '&') {
    			*astate = SS(0, S_AMP);
    			return UNVIS_NOCHAR;
    		}
    		if ((flag & VIS_MIMESTYLE) && c == '=') {
    			*astate = SS(0, S_MIME1);
    			return UNVIS_NOCHAR;
    		}
    		*cp = c;
    		return UNVIS_VALID;
    
    	case S_START:
    		switch(c) {
    		case '\\':
    			*cp = c;
    			*astate = SS(0, S_GROUND);
    			return UNVIS_VALID;
    		case '0': case '1': case '2': case '3':
    		case '4': case '5': case '6': case '7':
    			*cp = (c - '0');
    			*astate = SS(0, S_OCTAL2);
    			return UNVIS_NOCHAR;
    		case 'M':
    			*cp = (char)0200;
    			*astate = SS(0, S_META);
    			return UNVIS_NOCHAR;
    		case '^':
    			*astate = SS(0, S_CTRL);
    			return UNVIS_NOCHAR;
    		case 'n':
    			*cp = '\n';
    			*astate = SS(0, S_GROUND);
    			return UNVIS_VALID;
    		case 'r':
    			*cp = '\r';
    			*astate = SS(0, S_GROUND);
    			return UNVIS_VALID;
    		case 'b':
    			*cp = '\b';
    			*astate = SS(0, S_GROUND);
    			return UNVIS_VALID;
    		case 'a':
    			*cp = '\007';
    			*astate = SS(0, S_GROUND);
    			return UNVIS_VALID;
    		case 'v':
    			*cp = '\v';
    			*astate = SS(0, S_GROUND);
    			return UNVIS_VALID;
    		case 't':
    			*cp = '\t';
    			*astate = SS(0, S_GROUND);
    			return UNVIS_VALID;
    		case 'f':
    			*cp = '\f';
    			*astate = SS(0, S_GROUND);
    			return UNVIS_VALID;
    		case 's':
    			*cp = ' ';
    			*astate = SS(0, S_GROUND);
    			return UNVIS_VALID;
    		case 'E':
    			*cp = '\033';
    			*astate = SS(0, S_GROUND);
    			return UNVIS_VALID;
    		case 'x':
    			*astate = SS(0, S_HEX);
    			return UNVIS_NOCHAR;
    		case '\n':
    			/*
    			 * hidden newline
    			 */
    			*astate = SS(0, S_GROUND);
    			return UNVIS_NOCHAR;
    		case '$':
    			/*
    			 * hidden marker
    			 */
    			*astate = SS(0, S_GROUND);
    			return UNVIS_NOCHAR;
    		default:
    			if (isgraph(c)) {
    				*cp = c;
    				*astate = SS(0, S_GROUND);
    				return UNVIS_VALID;
    			}
    		}
    		goto bad;
    
    	case S_META:
    		if (c == '-')
    			*astate = SS(0, S_META1);
    		else if (c == '^')
    			*astate = SS(0, S_CTRL);
    		else
    			goto bad;
    		return UNVIS_NOCHAR;
    
    	case S_META1:
    		*astate = SS(0, S_GROUND);
    		*cp |= c;
    		return UNVIS_VALID;
    
    	case S_CTRL:
    		if (c == '?')
    			*cp |= 0177;
    		else
    			*cp |= c & 037;
    		*astate = SS(0, S_GROUND);
    		return UNVIS_VALID;
    
    	case S_OCTAL2:	/* second possible octal digit */
    		if (isoctal(uc)) {
    			/*
    			 * yes - and maybe a third
    			 */
    			*cp = (*cp << 3) + (c - '0');
    			*astate = SS(0, S_OCTAL3);
    			return UNVIS_NOCHAR;
    		}
    		/*
    		 * no - done with current sequence, push back passed char
    		 */
    		*astate = SS(0, S_GROUND);
    		return UNVIS_VALIDPUSH;
    
    	case S_OCTAL3:	/* third possible octal digit */
    		*astate = SS(0, S_GROUND);
    		if (isoctal(uc)) {
    			*cp = (*cp << 3) + (c - '0');
    			return UNVIS_VALID;
    		}
    		/*
    		 * we were done, push back passed char
    		 */
    		return UNVIS_VALIDPUSH;
    
    	case S_HEX:
    		if (!isxdigit(uc))
    			goto bad;
    		/*FALLTHROUGH*/
    	case S_HEX1:
    		if (isxdigit(uc)) {
    			*cp = xtod(uc);
    			*astate = SS(0, S_HEX2);
    			return UNVIS_NOCHAR;
    		}
    		/*
    		 * no - done with current sequence, push back passed char
    		 */
    		*astate = SS(0, S_GROUND);
    		return UNVIS_VALIDPUSH;
    
    	case S_HEX2:
    		*astate = S_GROUND;
    		if (isxdigit(uc)) {
    			*cp = xtod(uc) | (*cp << 4);
    			return UNVIS_VALID;
    		}
    		return UNVIS_VALIDPUSH;
    
    	case S_MIME1:
    		if (uc == '\n' || uc == '\r') {
    			*astate = SS(0, S_EATCRNL);
    			return UNVIS_NOCHAR;
    		}
    		if (isxdigit(uc) && (isdigit(uc) || isupper(uc))) {
    			*cp = XTOD(uc);
    			*astate = SS(0, S_MIME2);
    			return UNVIS_NOCHAR;
    		}
    		goto bad;
    
    	case S_MIME2:
    		if (isxdigit(uc) && (isdigit(uc) || isupper(uc))) {
    			*astate = SS(0, S_GROUND);
    			*cp = XTOD(uc) | (*cp << 4);
    			return UNVIS_VALID;
    		}
    		goto bad;
    
    	case S_EATCRNL:
    		switch (uc) {
    		case '\r':
    		case '\n':
    			return UNVIS_NOCHAR;
    		case '=':
    			*astate = SS(0, S_MIME1);
    			return UNVIS_NOCHAR;
    		default:
    			*cp = uc;
    			*astate = SS(0, S_GROUND);
    			return UNVIS_VALID;
    		}
    
    	case S_AMP:
    		*cp = 0;
    		if (uc == '#') {
    			*astate = SS(0, S_NUMBER);
    			return UNVIS_NOCHAR;
    		}
    		*astate = SS(0, S_STRING);
    		/*FALLTHROUGH*/
    
    	case S_STRING:
    		ia = *cp;		/* index in the array */
    		is = GI(*astate);	/* index in the string */
    		lc = is == 0 ? 0 : nv[ia].name[is - 1];	/* last character */
    
    		if (uc == ';')
    			uc = '\0';
    
    		for (; ia < __arraycount(nv); ia++) {
    			if (is != 0 && nv[ia].name[is - 1] != lc)
    				goto bad;
    			if (nv[ia].name[is] == uc)
    				break;
    		}
    
    		if (ia == __arraycount(nv))
    			goto bad;
    
    		if (uc != 0) {
    			*cp = ia;
    			*astate = SS(is + 1, S_STRING);
    			return UNVIS_NOCHAR;
    		}
    
    		*cp = nv[ia].value;
    		*astate = SS(0, S_GROUND);
    		return UNVIS_VALID;
    
    	case S_NUMBER:
    		if (uc == ';')
    			return UNVIS_VALID;
    		if (!isdigit(uc))
    			goto bad;
    		*cp += (*cp * 10) + uc - '0';
    		return UNVIS_NOCHAR;
    
    	default:
    	bad:
    		/*
    		 * decoder in unknown state - (probably uninitialized)
    		 */
    		*astate = SS(0, S_GROUND);
    		return UNVIS_SYNBAD;
    	}
    }
    
    /*
     * strnunvisx - decode src into dst
     *
     *	Number of chars decoded into dst is returned, -1 on error.
     *	Dst is null terminated.
     */
    
    int
    strnunvisx(char *dst, size_t dlen, const char *src, int flag)
    {
    	char c;
    	char t = '\0', *start = dst;
    	int state = 0;
    
    	_DIAGASSERT(src != NULL);
    	_DIAGASSERT(dst != NULL);
    #define CHECKSPACE() \
    	do { \
    		if (dlen-- == 0) { \
    			errno = ENOSPC; \
    			return -1; \
    		} \
    	} while (/*CONSTCOND*/0)
    
    	while ((c = *src++) != '\0') {
     again:
    		switch (unvis(&t, c, &state, flag)) {
    		case UNVIS_VALID:
    			CHECKSPACE();
    			*dst++ = t;
    			break;
    		case UNVIS_VALIDPUSH:
    			CHECKSPACE();
    			*dst++ = t;
    			goto again;
    		case 0:
    		case UNVIS_NOCHAR:
    			break;
    		case UNVIS_SYNBAD:
    			errno = EINVAL;
    			return -1;
    		default:
    			_DIAGASSERT(/*CONSTCOND*/0);
    			errno = EINVAL;
    			return -1;
    		}
    	}
    	if (unvis(&t, c, &state, UNVIS_END) == UNVIS_VALID) {
    		CHECKSPACE();
    		*dst++ = t;
    	}
    	CHECKSPACE();
    	*dst = '\0';
    	return (int)(dst - start);
    }
    
    int
    strunvisx(char *dst, const char *src, int flag)
    {
    	return strnunvisx(dst, (size_t)~0, src, flag);
    }
    
    int
    strunvis(char *dst, const char *src)
    {
    	return strnunvisx(dst, (size_t)~0, src, 0);
    }
    
    /*
     * NetBSD added an strnvis and unfortunately made it incompatible with the
     * existing one in OpenBSD and Freedesktop's libbsd (the former having existed
     * for over ten years). Despite this incompatibility being reported during
     * development (see http://gnats.netbsd.org/44977) they still shipped it.
     * Even more unfortunately FreeBSD and later macOS picked up this incompatible
     * implementation.
     *
     * Provide both implementations and default for now on the historical one to
     * avoid breakage, we will switch to the NetBSD one in libbsd 0.10.0 or so.
     *
     * OpenBSD, 2001: strnunvis(char *dst, const char *src, size_t dlen);
     * NetBSD: 2012,  strnunvis(char *dst, size_t dlen, const char *src);
     */
    ssize_t
    strnunvis_openbsd(char *, const char *, size_t);
    ssize_t
    strnunvis_openbsd(char *dst, const char *src, size_t dlen)
    {
    	return strnunvisx(dst, dlen, src, 0);
    }
    libbsd_symver_default(strnunvis, strnunvis_openbsd, LIBBSD_0.2);
    
    int
    strnunvis_netbsd(char *, size_t, const char *);
    int
    strnunvis_netbsd(char *dst, size_t dlen, const char *src)
    {
    	return strnunvisx(dst, dlen, src, 0);
    }
    libbsd_symver_variant(strnunvis, strnunvis_netbsd, LIBBSD_0.9.1);