_sre.c

python s60 1.4.5版本的源代码

            SRE_IS_WORD((int) ptr[0]) : 0;
        return this == that;

    case SRE_AT_LOC_BOUNDARY:
        if (state->beginning == state->end)
            return 0;
        that = ((void*) ptr > state->beginning) ?
            SRE_LOC_IS_WORD((int) ptr[-1]) : 0;
        this = ((void*) ptr < state->end) ?
            SRE_LOC_IS_WORD((int) ptr[0]) : 0;
        return this != that;

    case SRE_AT_LOC_NON_BOUNDARY:
        if (state->beginning == state->end)
            return 0;
        that = ((void*) ptr > state->beginning) ?
            SRE_LOC_IS_WORD((int) ptr[-1]) : 0;
        this = ((void*) ptr < state->end) ?
            SRE_LOC_IS_WORD((int) ptr[0]) : 0;
        return this == that;

#if defined(HAVE_UNICODE)
    case SRE_AT_UNI_BOUNDARY:
        if (state->beginning == state->end)
            return 0;
        that = ((void*) ptr > state->beginning) ?
            SRE_UNI_IS_WORD((int) ptr[-1]) : 0;
        this = ((void*) ptr < state->end) ?
            SRE_UNI_IS_WORD((int) ptr[0]) : 0;
        return this != that;

    case SRE_AT_UNI_NON_BOUNDARY:
        if (state->beginning == state->end)
            return 0;
        that = ((void*) ptr > state->beginning) ?
            SRE_UNI_IS_WORD((int) ptr[-1]) : 0;
        this = ((void*) ptr < state->end) ?
            SRE_UNI_IS_WORD((int) ptr[0]) : 0;
        return this == that;
#endif

    }

    return 0;
}

LOCAL(int)
SRE_CHARSET(SRE_CODE* set, SRE_CODE ch)
{
    /* check if character is a member of the given set */

    int ok = 1;

    for (;;) {
        switch (*set++) {

        case SRE_OP_LITERAL:
            /* <LITERAL> <code> */
            if (ch == set[0])
                return ok;
            set++;
            break;

        case SRE_OP_RANGE:
            /* <RANGE> <lower> <upper> */
            if (set[0] <= ch && ch <= set[1])
                return ok;
            set += 2;
            break;

        case SRE_OP_CHARSET:
            /* <CHARSET> <bitmap> (16 bits per code word) */
            if (ch < 256 && (set[ch >> 4] & (1 << (ch & 15))))
                return ok;
            set += 16;
            break;

        case SRE_OP_BIGCHARSET:
            /* <BIGCHARSET> <blockcount> <256 blockindices> <blocks> */
        {
            int count, block;
            count = *(set++);
            block = ((unsigned char*)set)[ch >> 8];
            set += 128;
            if (set[block*16 + ((ch & 255)>>4)] & (1 << (ch & 15)))
                return ok;
            set += count*16;
            break;
        }

        case SRE_OP_CATEGORY:
            /* <CATEGORY> <code> */
            if (sre_category(set[0], (int) ch))
                return ok;
            set += 1;
            break;

        case SRE_OP_NEGATE:
            ok = !ok;
            break;

        case SRE_OP_FAILURE:
            return !ok;

        default:
            /* internal error -- there's not much we can do about it
               here, so let's just pretend it didn't match... */
            return 0;
        }
    }
}

LOCAL(int) SRE_MATCH(SRE_STATE* state, SRE_CODE* pattern, int level);

LOCAL(int)
SRE_COUNT(SRE_STATE* state, SRE_CODE* pattern, int maxcount, int level)
{
    SRE_CODE chr;
    SRE_CHAR* ptr = state->ptr;
    SRE_CHAR* end = state->end;
    int i;

    /* adjust end */
    if (maxcount < end - ptr && maxcount != 65535)
        end = ptr + maxcount;

    switch (pattern[0]) {

    case SRE_OP_ANY:
        /* repeated dot wildcard. */
        TRACE(("|%p|%p|COUNT ANY\n", pattern, ptr));
        while (ptr < end && !SRE_IS_LINEBREAK(*ptr))
            ptr++;
        break;

    case SRE_OP_ANY_ALL:
        /* repeated dot wildcare.  skip to the end of the target
           string, and backtrack from there */
        TRACE(("|%p|%p|COUNT ANY_ALL\n", pattern, ptr));
        ptr = end;
        break;

    case SRE_OP_LITERAL:
        /* repeated literal */
        chr = pattern[1];
        TRACE(("|%p|%p|COUNT LITERAL %d\n", pattern, ptr, chr));
        while (ptr < end && (SRE_CODE) *ptr == chr)
            ptr++;
        break;

    case SRE_OP_LITERAL_IGNORE:
        /* repeated literal */
        chr = pattern[1];
        TRACE(("|%p|%p|COUNT LITERAL_IGNORE %d\n", pattern, ptr, chr));
        while (ptr < end && (SRE_CODE) state->lower(*ptr) == chr)
            ptr++;
        break;

    case SRE_OP_NOT_LITERAL:
        /* repeated non-literal */
        chr = pattern[1];
        TRACE(("|%p|%p|COUNT NOT_LITERAL %d\n", pattern, ptr, chr));
        while (ptr < end && (SRE_CODE) *ptr != chr)
            ptr++;
        break;
                
    case SRE_OP_NOT_LITERAL_IGNORE:
        /* repeated non-literal */
        chr = pattern[1];
        TRACE(("|%p|%p|COUNT NOT_LITERAL_IGNORE %d\n", pattern, ptr, chr));
        while (ptr < end && (SRE_CODE) state->lower(*ptr) != chr)
            ptr++;
        break;

    case SRE_OP_IN:
        /* repeated set */
        TRACE(("|%p|%p|COUNT IN\n", pattern, ptr));
        while (ptr < end && SRE_CHARSET(pattern + 2, *ptr))
            ptr++;
        break;

    default:
        /* repeated single character pattern */
        TRACE(("|%p|%p|COUNT SUBPATTERN\n", pattern, ptr));
        while ((SRE_CHAR*) state->ptr < end) {
            i = SRE_MATCH(state, pattern, level);
            if (i < 0)
                return i;
            if (!i)
                break;
        }
        TRACE(("|%p|%p|COUNT %d\n", pattern, ptr,
               (SRE_CHAR*) state->ptr - ptr));
        return (SRE_CHAR*) state->ptr - ptr;
    }

    TRACE(("|%p|%p|COUNT %d\n", pattern, ptr, ptr - (SRE_CHAR*) state->ptr));
    return ptr - (SRE_CHAR*) state->ptr;
}

#if 0 /* not used in this release */
LOCAL(int)
SRE_INFO(SRE_STATE* state, SRE_CODE* pattern)
{
    /* check if an SRE_OP_INFO block matches at the current position.
       returns the number of SRE_CODE objects to skip if successful, 0
       if no match */

    SRE_CHAR* end = state->end;
    SRE_CHAR* ptr = state->ptr;
    int i;

    /* check minimal length */
    if (pattern[3] && (end - ptr) < pattern[3])
        return 0;

    /* check known prefix */
    if (pattern[2] & SRE_INFO_PREFIX && pattern[5] > 1) {
        /* <length> <skip> <prefix data> <overlap data> */
        for (i = 0; i < pattern[5]; i++)
            if ((SRE_CODE) ptr[i] != pattern[7 + i])
                return 0;
        return pattern[0] + 2 * pattern[6];
    }
    return pattern[0];
}
#endif

LOCAL(int)
SRE_MATCH(SRE_STATE* state, SRE_CODE* pattern, int level)
{
    /* check if string matches the given pattern.  returns <0 for
       error, 0 for failure, and 1 for success */

    SRE_CHAR* end = state->end;
    SRE_CHAR* ptr = state->ptr;
    int i, count;
    SRE_REPEAT* rp;
    int lastmark;
    SRE_CODE chr;

    SRE_REPEAT rep; /* FIXME: <fl> allocate in STATE instead */

    TRACE(("|%p|%p|ENTER %d\n", pattern, ptr, level));

#if defined(USE_STACKCHECK)
    if (level % 10 == 0 && PyOS_CheckStack())
        return SRE_ERROR_RECURSION_LIMIT;
#endif

#if defined(USE_RECURSION_LIMIT)
    if (level > USE_RECURSION_LIMIT)
        return SRE_ERROR_RECURSION_LIMIT;
#endif

    if (pattern[0] == SRE_OP_INFO) {
        /* optimization info block */
        /* <INFO> <1=skip> <2=flags> <3=min> ... */
        if (pattern[3] && (end - ptr) < pattern[3]) {
            TRACE(("reject (got %d chars, need %d)\n",
                   (end - ptr), pattern[3]));
            return 0;
        }
        pattern += pattern[1] + 1;
    }

    for (;;) {

        switch (*pattern++) {

        case SRE_OP_FAILURE:
            /* immediate failure */
            TRACE(("|%p|%p|FAILURE\n", pattern, ptr));
            return 0;

        case SRE_OP_SUCCESS:
            /* end of pattern */
            TRACE(("|%p|%p|SUCCESS\n", pattern, ptr));
            state->ptr = ptr;
            return 1;

        case SRE_OP_AT:
            /* match at given position */
            /* <AT> <code> */
            TRACE(("|%p|%p|AT %d\n", pattern, ptr, *pattern));
            if (!SRE_AT(state, ptr, *pattern))
                return 0;
            pattern++;
            break;

        case SRE_OP_CATEGORY:
            /* match at given category */
            /* <CATEGORY> <code> */
            TRACE(("|%p|%p|CATEGORY %d\n", pattern, ptr, *pattern));
            if (ptr >= end || !sre_category(pattern[0], ptr[0]))
                return 0;
            pattern++;
            ptr++;
            break;

        case SRE_OP_LITERAL:
            /* match literal string */
            /* <LITERAL> <code> */
            TRACE(("|%p|%p|LITERAL %d\n", pattern, ptr, *pattern));
            if (ptr >= end || (SRE_CODE) ptr[0] != pattern[0])
                return 0;
            pattern++;
            ptr++;
            break;

        case SRE_OP_NOT_LITERAL:
            /* match anything that is not literal character */
            /* <NOT_LITERAL> <code> */
            TRACE(("|%p|%p|NOT_LITERAL %d\n", pattern, ptr, *pattern));
            if (ptr >= end || (SRE_CODE) ptr[0] == pattern[0])
                return 0;
            pattern++;
            ptr++;
            break;

        case SRE_OP_ANY:
            /* match anything (except a newline) */
            /* <ANY> */
            TRACE(("|%p|%p|ANY\n", pattern, ptr));
            if (ptr >= end || SRE_IS_LINEBREAK(ptr[0]))
                return 0;
            ptr++;
            break;

        case SRE_OP_ANY_ALL:
            /* match anything */
            /* <ANY_ALL> */
            TRACE(("|%p|%p|ANY_ALL\n", pattern, ptr));
            if (ptr >= end)
                return 0;
            ptr++;
            break;

        case SRE_OP_IN:
            /* match set member (or non_member) */
            /* <IN> <skip> <set> */
            TRACE(("|%p|%p|IN\n", pattern, ptr));
            if (ptr >= end || !SRE_CHARSET(pattern + 1, *ptr))
                return 0;
            pattern += pattern[0];
            ptr++;
            break;

        case SRE_OP_GROUPREF:
            /* match backreference */
            TRACE(("|%p|%p|GROUPREF %d\n", pattern, ptr, pattern[0]));
            i = pattern[0];
            {
                SRE_CHAR* p = (SRE_CHAR*) state->mark[i+i];
                SRE_CHAR* e = (SRE_CHAR*) state->mark[i+i+1];
                if (!p || !e || e < p)
                    return 0;
                while (p < e) {
                    if (ptr >= end || *ptr != *p)
                        return 0;
                    p++; ptr++;
                }
            }
            pattern++;
            break;

        case SRE_OP_GROUPREF_IGNORE:
            /* match backreference */
            TRACE(("|%p|%p|GROUPREF_IGNORE %d\n", pattern, ptr, pattern[0]));
            i = pattern[0];
            {
                SRE_CHAR* p = (SRE_CHAR*) state->mark[i+i];
                SRE_CHAR* e = (SRE_CHAR*) state->mark[i+i+1];
                if (!p || !e || e < p)
                    return 0;
                while (p < e) {
                    if (ptr >= end ||
                        state->lower(*ptr) != state->lower(*p))
                        return 0;
                    p++; ptr++;
                }
            }
            pattern++;
            break;

        case SRE_OP_LITERAL_IGNORE:
            TRACE(("|%p|%p|LITERAL_IGNORE %d\n", pattern, ptr, pattern[0]));
            if (ptr >= end ||
                state->lower(*ptr) != state->lower(*pattern))
                return 0;
            pattern++;
            ptr++;
            break;

        case SRE_OP_NOT_LITERAL_IGNORE:
            TRACE(("|%p|%p|NOT_LITERAL_IGNORE %d\n", pattern, ptr, *pattern));
            if (ptr >= end ||
                state->lower(*ptr) == state->lower(*pattern))
                return 0;
            pattern++;
            ptr++;
            break;

        case SRE_OP_IN_IGNORE:
            TRACE(("|%p|%p|IN_IGNORE\n", pattern, ptr));
            if (ptr >= end
                || !SRE_CHARSET(pattern + 1, (SRE_CODE) state->lower(*ptr)))
                return 0;
            pattern += pattern[0];
            ptr++;
            break;

        case SRE_OP_MARK:
            /* set mark */
            /* <MARK> <gid> */
            TRACE(("|%p|%p|MARK %d\n", pattern, ptr, pattern[0]));
            i = pattern[0];
            if (i & 1)
                state->lastindex = i/2 + 1;
            if (i > state->lastmark)
                state->lastmark = i;
            state->mark[i] = ptr;
            pattern++;
            break;

        case SRE_OP_JUMP:
        case SRE_OP_INFO:
            /* jump forward */
            /* <JUMP> <offset> */
            TRACE(("|%p|%p|JUMP %d\n", pattern, ptr, pattern[0]));
            pattern += pattern[0];
            break;

        case SRE_OP_ASSERT:
            /* assert subpattern */
            /* <ASSERT> <skip> <back> <pattern> */
            TRACE(("|%p|%p|ASSERT %d\n", pattern, ptr, pattern[1]));
            state->ptr = ptr - pattern[1];
            if (state->ptr < state->beginning)
                return 0;
            i = SRE_MATCH(state, pattern + 2, level + 1);
            if (i <= 0)
                return i;
            pattern += pattern[0];
            break;

        case SRE_OP_ASSERT_NOT:
            /* assert not subpattern */
            /* <ASSERT_NOT> <skip> <back> <pattern> */
            TRACE(("|%p|%p|ASSERT_NOT %d\n", pattern, ptr, pattern[1]));