misc/libphysfs/physfs_unicode.c
author nemo
Mon, 10 Apr 2017 12:06:43 -0400
changeset 12213 bb5522e88ab2
parent 8524 a65e9bcf0a03
permissions -rw-r--r--
bulk copy of latest physfs to our misc/libphysfs since this seems to fix an off-by-1 error reliably hit in readln read of 1 byte probably introduced in the addition of the buffered read. Whether this is excessive or whether libphysfs should even be maintained by us is another matter. But at least we shouldn't crash

#define __PHYSICSFS_INTERNAL__
#include "physfs_internal.h"


/*
 * From rfc3629, the UTF-8 spec:
 *  https://www.ietf.org/rfc/rfc3629.txt
 *
 *   Char. number range  |        UTF-8 octet sequence
 *      (hexadecimal)    |              (binary)
 *   --------------------+---------------------------------------------
 *   0000 0000-0000 007F | 0xxxxxxx
 *   0000 0080-0000 07FF | 110xxxxx 10xxxxxx
 *   0000 0800-0000 FFFF | 1110xxxx 10xxxxxx 10xxxxxx
 *   0001 0000-0010 FFFF | 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
 */


/*
 * This may not be the best value, but it's one that isn't represented
 *  in Unicode (0x10FFFF is the largest codepoint value). We return this
 *  value from utf8codepoint() if there's bogus bits in the
 *  stream. utf8codepoint() will turn this value into something
 *  reasonable (like a question mark), for text that wants to try to recover,
 *  whereas utf8valid() will use the value to determine if a string has bad
 *  bits.
 */
#define UNICODE_BOGUS_CHAR_VALUE 0xFFFFFFFF

/*
 * This is the codepoint we currently return when there was bogus bits in a
 *  UTF-8 string. May not fly in Asian locales?
 */
#define UNICODE_BOGUS_CHAR_CODEPOINT '?'

static PHYSFS_uint32 utf8codepoint(const char **_str)
{
    const char *str = *_str;
    PHYSFS_uint32 retval = 0;
    PHYSFS_uint32 octet = (PHYSFS_uint32) ((PHYSFS_uint8) *str);
    PHYSFS_uint32 octet2, octet3, octet4;

    if (octet == 0)  /* null terminator, end of string. */
        return 0;

    else if (octet < 128)  /* one octet char: 0 to 127 */
    {
        (*_str)++;  /* skip to next possible start of codepoint. */
        return octet;
    } /* else if */

    else if ((octet > 127) && (octet < 192))  /* bad (starts with 10xxxxxx). */
    {
        /*
         * Apparently each of these is supposed to be flagged as a bogus
         *  char, instead of just resyncing to the next valid codepoint.
         */
        (*_str)++;  /* skip to next possible start of codepoint. */
        return UNICODE_BOGUS_CHAR_VALUE;
    } /* else if */

    else if (octet < 224)  /* two octets */
    {
        (*_str)++;  /* advance at least one byte in case of an error */
        octet -= (128+64);
        octet2 = (PHYSFS_uint32) ((PHYSFS_uint8) *(++str));
        if ((octet2 & (128+64)) != 128)  /* Format isn't 10xxxxxx? */
            return UNICODE_BOGUS_CHAR_VALUE;

        *_str += 1;  /* skip to next possible start of codepoint. */
        retval = ((octet << 6) | (octet2 - 128));
        if ((retval >= 0x80) && (retval <= 0x7FF))
            return retval;
    } /* else if */

    else if (octet < 240)  /* three octets */
    {
        (*_str)++;  /* advance at least one byte in case of an error */
        octet -= (128+64+32);
        octet2 = (PHYSFS_uint32) ((PHYSFS_uint8) *(++str));
        if ((octet2 & (128+64)) != 128)  /* Format isn't 10xxxxxx? */
            return UNICODE_BOGUS_CHAR_VALUE;

        octet3 = (PHYSFS_uint32) ((PHYSFS_uint8) *(++str));
        if ((octet3 & (128+64)) != 128)  /* Format isn't 10xxxxxx? */
            return UNICODE_BOGUS_CHAR_VALUE;

        *_str += 2;  /* skip to next possible start of codepoint. */
        retval = ( ((octet << 12)) | ((octet2-128) << 6) | ((octet3-128)) );

        /* There are seven "UTF-16 surrogates" that are illegal in UTF-8. */
        switch (retval)
        {
            case 0xD800:
            case 0xDB7F:
            case 0xDB80:
            case 0xDBFF:
            case 0xDC00:
            case 0xDF80:
            case 0xDFFF:
                return UNICODE_BOGUS_CHAR_VALUE;
        } /* switch */

        /* 0xFFFE and 0xFFFF are illegal, too, so we check them at the edge. */
        if ((retval >= 0x800) && (retval <= 0xFFFD))
            return retval;
    } /* else if */

    else if (octet < 248)  /* four octets */
    {
        (*_str)++;  /* advance at least one byte in case of an error */
        octet -= (128+64+32+16);
        octet2 = (PHYSFS_uint32) ((PHYSFS_uint8) *(++str));
        if ((octet2 & (128+64)) != 128)  /* Format isn't 10xxxxxx? */
            return UNICODE_BOGUS_CHAR_VALUE;

        octet3 = (PHYSFS_uint32) ((PHYSFS_uint8) *(++str));
        if ((octet3 & (128+64)) != 128)  /* Format isn't 10xxxxxx? */
            return UNICODE_BOGUS_CHAR_VALUE;

        octet4 = (PHYSFS_uint32) ((PHYSFS_uint8) *(++str));
        if ((octet4 & (128+64)) != 128)  /* Format isn't 10xxxxxx? */
            return UNICODE_BOGUS_CHAR_VALUE;

        *_str += 3;  /* skip to next possible start of codepoint. */
        retval = ( ((octet << 18)) | ((octet2 - 128) << 12) |
                   ((octet3 - 128) << 6) | ((octet4 - 128)) );
        if ((retval >= 0x10000) && (retval <= 0x10FFFF))
            return retval;
    } /* else if */

    /*
     * Five and six octet sequences became illegal in rfc3629.
     *  We throw the codepoint away, but parse them to make sure we move
     *  ahead the right number of bytes and don't overflow the buffer.
     */

    else if (octet < 252)  /* five octets */
    {
        (*_str)++;  /* advance at least one byte in case of an error */
        octet = (PHYSFS_uint32) ((PHYSFS_uint8) *(++str));
        if ((octet & (128+64)) != 128)  /* Format isn't 10xxxxxx? */
            return UNICODE_BOGUS_CHAR_VALUE;

        octet = (PHYSFS_uint32) ((PHYSFS_uint8) *(++str));
        if ((octet & (128+64)) != 128)  /* Format isn't 10xxxxxx? */
            return UNICODE_BOGUS_CHAR_VALUE;

        octet = (PHYSFS_uint32) ((PHYSFS_uint8) *(++str));
        if ((octet & (128+64)) != 128)  /* Format isn't 10xxxxxx? */
            return UNICODE_BOGUS_CHAR_VALUE;

        octet = (PHYSFS_uint32) ((PHYSFS_uint8) *(++str));
        if ((octet & (128+64)) != 128)  /* Format isn't 10xxxxxx? */
            return UNICODE_BOGUS_CHAR_VALUE;

        *_str += 4;  /* skip to next possible start of codepoint. */
        return UNICODE_BOGUS_CHAR_VALUE;
    } /* else if */

    else  /* six octets */
    {
        (*_str)++;  /* advance at least one byte in case of an error */
        octet = (PHYSFS_uint32) ((PHYSFS_uint8) *(++str));
        if ((octet & (128+64)) != 128)  /* Format isn't 10xxxxxx? */
            return UNICODE_BOGUS_CHAR_VALUE;

        octet = (PHYSFS_uint32) ((PHYSFS_uint8) *(++str));
        if ((octet & (128+64)) != 128)  /* Format isn't 10xxxxxx? */
            return UNICODE_BOGUS_CHAR_VALUE;

        octet = (PHYSFS_uint32) ((PHYSFS_uint8) *(++str));
        if ((octet & (128+64)) != 128)  /* Format isn't 10xxxxxx? */
            return UNICODE_BOGUS_CHAR_VALUE;

        octet = (PHYSFS_uint32) ((PHYSFS_uint8) *(++str));
        if ((octet & (128+64)) != 128)  /* Format isn't 10xxxxxx? */
            return UNICODE_BOGUS_CHAR_VALUE;

        octet = (PHYSFS_uint32) ((PHYSFS_uint8) *(++str));
        if ((octet & (128+64)) != 128)  /* Format isn't 10xxxxxx? */
            return UNICODE_BOGUS_CHAR_VALUE;

        *_str += 6;  /* skip to next possible start of codepoint. */
        return UNICODE_BOGUS_CHAR_VALUE;
    } /* else if */

    return UNICODE_BOGUS_CHAR_VALUE;
} /* utf8codepoint */


void PHYSFS_utf8ToUcs4(const char *src, PHYSFS_uint32 *dst, PHYSFS_uint64 len)
{
    len -= sizeof (PHYSFS_uint32);   /* save room for null char. */
    while (len >= sizeof (PHYSFS_uint32))
    {
        PHYSFS_uint32 cp = utf8codepoint(&src);
        if (cp == 0)
            break;
        else if (cp == UNICODE_BOGUS_CHAR_VALUE)
            cp = UNICODE_BOGUS_CHAR_CODEPOINT;
        *(dst++) = cp;
        len -= sizeof (PHYSFS_uint32);
    } /* while */

    *dst = 0;
} /* PHYSFS_utf8ToUcs4 */


void PHYSFS_utf8ToUcs2(const char *src, PHYSFS_uint16 *dst, PHYSFS_uint64 len)
{
    len -= sizeof (PHYSFS_uint16);   /* save room for null char. */
    while (len >= sizeof (PHYSFS_uint16))
    {
        PHYSFS_uint32 cp = utf8codepoint(&src);
        if (cp == 0)
            break;
        else if (cp == UNICODE_BOGUS_CHAR_VALUE)
            cp = UNICODE_BOGUS_CHAR_CODEPOINT;

        if (cp > 0xFFFF)  /* UTF-16 surrogates (bogus chars in UCS-2) */
            cp = UNICODE_BOGUS_CHAR_CODEPOINT;

        *(dst++) = cp;
        len -= sizeof (PHYSFS_uint16);
    } /* while */

    *dst = 0;
} /* PHYSFS_utf8ToUcs2 */


void PHYSFS_utf8ToUtf16(const char *src, PHYSFS_uint16 *dst, PHYSFS_uint64 len)
{
    len -= sizeof (PHYSFS_uint16);   /* save room for null char. */
    while (len >= sizeof (PHYSFS_uint16))
    {
        PHYSFS_uint32 cp = utf8codepoint(&src);
        if (cp == 0)
            break;
        else if (cp == UNICODE_BOGUS_CHAR_VALUE)
            cp = UNICODE_BOGUS_CHAR_CODEPOINT;

        if (cp > 0xFFFF)  /* encode as surrogate pair */
        {
            if (len < (sizeof (PHYSFS_uint16) * 2))
                break;  /* not enough room for the pair, stop now. */

            cp -= 0x10000;  /* Make this a 20-bit value */

            *(dst++) = 0xD800 + ((cp >> 10) & 0x3FF);
            len -= sizeof (PHYSFS_uint16);

            cp = 0xDC00 + (cp & 0x3FF);
        } /* if */

        *(dst++) = cp;
        len -= sizeof (PHYSFS_uint16);
    } /* while */

    *dst = 0;
} /* PHYSFS_utf8ToUtf16 */

static void utf8fromcodepoint(PHYSFS_uint32 cp, char **_dst, PHYSFS_uint64 *_len)
{
    char *dst = *_dst;
    PHYSFS_uint64 len = *_len;

    if (len == 0)
        return;

    if (cp > 0x10FFFF)
        cp = UNICODE_BOGUS_CHAR_CODEPOINT;
    else if ((cp == 0xFFFE) || (cp == 0xFFFF))  /* illegal values. */
        cp = UNICODE_BOGUS_CHAR_CODEPOINT;
    else
    {
        /* There are seven "UTF-16 surrogates" that are illegal in UTF-8. */
        switch (cp)
        {
            case 0xD800:
            case 0xDB7F:
            case 0xDB80:
            case 0xDBFF:
            case 0xDC00:
            case 0xDF80:
            case 0xDFFF:
                cp = UNICODE_BOGUS_CHAR_CODEPOINT;
        } /* switch */
    } /* else */

    /* Do the encoding... */
    if (cp < 0x80)
    {
        *(dst++) = (char) cp;
        len--;
    } /* if */

    else if (cp < 0x800)
    {
        if (len < 2)
            len = 0;
        else
        {
            *(dst++) = (char) ((cp >> 6) | 128 | 64);
            *(dst++) = (char) (cp & 0x3F) | 128;
            len -= 2;
        } /* else */
    } /* else if */

    else if (cp < 0x10000)
    {
        if (len < 3)
            len = 0;
        else
        {
            *(dst++) = (char) ((cp >> 12) | 128 | 64 | 32);
            *(dst++) = (char) ((cp >> 6) & 0x3F) | 128;
            *(dst++) = (char) (cp & 0x3F) | 128;
            len -= 3;
        } /* else */
    } /* else if */

    else
    {
        if (len < 4)
            len = 0;
        else
        {
            *(dst++) = (char) ((cp >> 18) | 128 | 64 | 32 | 16);
            *(dst++) = (char) ((cp >> 12) & 0x3F) | 128;
            *(dst++) = (char) ((cp >> 6) & 0x3F) | 128;
            *(dst++) = (char) (cp & 0x3F) | 128;
            len -= 4;
        } /* else if */
    } /* else */

    *_dst = dst;
    *_len = len;
} /* utf8fromcodepoint */

#define UTF8FROMTYPE(typ, src, dst, len) \
    if (len == 0) return; \
    len--;  \
    while (len) \
    { \
        const PHYSFS_uint32 cp = (PHYSFS_uint32) ((typ) (*(src++))); \
        if (cp == 0) break; \
        utf8fromcodepoint(cp, &dst, &len); \
    } \
    *dst = '\0'; \

void PHYSFS_utf8FromUcs4(const PHYSFS_uint32 *src, char *dst, PHYSFS_uint64 len)
{
    UTF8FROMTYPE(PHYSFS_uint32, src, dst, len);
} /* PHYSFS_utf8FromUcs4 */

void PHYSFS_utf8FromUcs2(const PHYSFS_uint16 *src, char *dst, PHYSFS_uint64 len)
{
    UTF8FROMTYPE(PHYSFS_uint64, src, dst, len);
} /* PHYSFS_utf8FromUcs2 */

/* latin1 maps to unicode codepoints directly, we just utf-8 encode it. */
void PHYSFS_utf8FromLatin1(const char *src, char *dst, PHYSFS_uint64 len)
{
    UTF8FROMTYPE(PHYSFS_uint8, src, dst, len);
} /* PHYSFS_utf8FromLatin1 */

#undef UTF8FROMTYPE


void PHYSFS_utf8FromUtf16(const PHYSFS_uint16 *src, char *dst, PHYSFS_uint64 len)
{
    if (len == 0)
        return;

    len--;
    while (len)
    {
        PHYSFS_uint32 cp = (PHYSFS_uint32) *(src++);
        if (cp == 0)
            break;

        /* Orphaned second half of surrogate pair? */
        if ((cp >= 0xDC00) && (cp <= 0xDFFF))
            cp = UNICODE_BOGUS_CHAR_CODEPOINT;
        else if ((cp >= 0xD800) && (cp <= 0xDBFF))  /* start surrogate pair! */
        {
            const PHYSFS_uint32 pair = (PHYSFS_uint32) *src;
            if ((pair < 0xDC00) || (pair > 0xDFFF))
                cp = UNICODE_BOGUS_CHAR_CODEPOINT;
            else
            {
                src++;  /* eat the other surrogate. */
                cp = (((cp - 0xD800) << 10) | (pair - 0xDC00));
            } /* else */
        } /* else if */

        utf8fromcodepoint(cp, &dst, &len);
    } /* while */

    *dst = '\0';
} /* PHYSFS_utf8FromUtf16 */


typedef struct CaseFoldMapping
{
    PHYSFS_uint32 from;
    PHYSFS_uint32 to0;
    PHYSFS_uint32 to1;
    PHYSFS_uint32 to2;
} CaseFoldMapping;

typedef struct CaseFoldHashBucket
{
    const PHYSFS_uint8 count;
    const CaseFoldMapping *list;
} CaseFoldHashBucket;

#include "physfs_casefolding.h"

static void locate_case_fold_mapping(const PHYSFS_uint32 from,
                                     PHYSFS_uint32 *to)
{
    PHYSFS_uint32 i;
    const PHYSFS_uint8 hashed = ((from ^ (from >> 8)) & 0xFF);
    const CaseFoldHashBucket *bucket = &case_fold_hash[hashed];
    const CaseFoldMapping *mapping = bucket->list;

    for (i = 0; i < bucket->count; i++, mapping++)
    {
        if (mapping->from == from)
        {
            to[0] = mapping->to0;
            to[1] = mapping->to1;
            to[2] = mapping->to2;
            return;
        } /* if */
    } /* for */

    /* Not found...there's no remapping for this codepoint. */
    to[0] = from;
    to[1] = 0;
    to[2] = 0;
} /* locate_case_fold_mapping */


static int utf8codepointcmp(const PHYSFS_uint32 cp1, const PHYSFS_uint32 cp2)
{
    PHYSFS_uint32 folded1[3], folded2[3];

    if (cp1 == cp2)
        return 0;  /* obviously matches. */

    locate_case_fold_mapping(cp1, folded1);
    locate_case_fold_mapping(cp2, folded2);

    if (folded1[0] < folded2[0])
        return -1;
    else if (folded1[0] > folded2[0])
        return 1;
    else if (folded1[1] < folded2[1])
        return -1;
    else if (folded1[1] > folded2[1])
        return 1;
    else if (folded1[2] < folded2[2])
        return -1;
    else if (folded1[2] > folded2[2])
        return 1;

    return 0;  /* complete match. */
} /* utf8codepointcmp */


int __PHYSFS_utf8stricmp(const char *str1, const char *str2)
{
    while (1)
    {
        const PHYSFS_uint32 cp1 = utf8codepoint(&str1);
        const PHYSFS_uint32 cp2 = utf8codepoint(&str2);
        const int rc = utf8codepointcmp(cp1, cp2);
        if (rc != 0)
            return rc;
        else if (cp1 == 0)
            break;  /* complete match. */
    } /* while */

    return 0;
} /* __PHYSFS_utf8stricmp */


int __PHYSFS_utf8strnicmp(const char *str1, const char *str2, PHYSFS_uint32 n)
{
    while (n > 0)
    {
        const PHYSFS_uint32 cp1 = utf8codepoint(&str1);
        const PHYSFS_uint32 cp2 = utf8codepoint(&str2);
        const int rc = utf8codepointcmp(cp1, cp2);
        if (rc != 0)
            return rc;
        else if (cp1 == 0)
            return 0;
        n--;
    } /* while */

    return 0;  /* matched to n chars. */
} /* __PHYSFS_utf8strnicmp */


int __PHYSFS_stricmpASCII(const char *str1, const char *str2)
{
    while (1)
    {
        const char ch1 = *(str1++);
        const char ch2 = *(str2++);
        const char cp1 = ((ch1 >= 'A') && (ch1 <= 'Z')) ? (ch1+32) : ch1;
        const char cp2 = ((ch2 >= 'A') && (ch2 <= 'Z')) ? (ch2+32) : ch2;
        if (cp1 < cp2)
            return -1;
        else if (cp1 > cp2)
            return 1;
        else if (cp1 == 0)  /* they're both null chars? */
            break;
    } /* while */

    return 0;
} /* __PHYSFS_stricmpASCII */


int __PHYSFS_strnicmpASCII(const char *str1, const char *str2, PHYSFS_uint32 n)
{
    while (n-- > 0)
    {
        const char ch1 = *(str1++);
        const char ch2 = *(str2++);
        const char cp1 = ((ch1 >= 'A') && (ch1 <= 'Z')) ? (ch1+32) : ch1;
        const char cp2 = ((ch2 >= 'A') && (ch2 <= 'Z')) ? (ch2+32) : ch2;
        if (cp1 < cp2)
            return -1;
        else if (cp1 > cp2)
            return 1;
        else if (cp1 == 0)  /* they're both null chars? */
            return 0;
    } /* while */

    return 0;
} /* __PHYSFS_strnicmpASCII */


/* end of physfs_unicode.c ... */