YQ Connector:Use docker-compose in integrational tests

1 files changed, 1825 insertions, 0 deletions

diff --git a/contrib/libs/pcre2/src/pcre2_study.c b/contrib/libs/pcre2/src/pcre2_study.c
new file mode 100644
index 0000000000..b259d246eb
--- /dev/null
+++ b/contrib/libs/pcre2/src/pcre2_study.c
@@ -0,0 +1,1825 @@
+/*************************************************
+*      Perl-Compatible Regular Expressions       *
+*************************************************/
+
+/* PCRE is a library of functions to support regular expressions whose syntax
+and semantics are as close as possible to those of the Perl 5 language.
+
+                       Written by Philip Hazel
+     Original API code Copyright (c) 1997-2012 University of Cambridge
+          New API code Copyright (c) 2016-2021 University of Cambridge
+
+-----------------------------------------------------------------------------
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright notice,
+      this list of conditions and the following disclaimer.
+
+    * 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.
+
+    * Neither the name of the University of Cambridge 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.
+-----------------------------------------------------------------------------
+*/
+
+/* This module contains functions for scanning a compiled pattern and
+collecting data (e.g. minimum matching length). */
+
+
+#ifdef HAVE_CONFIG_H
+#include <pcre2_config.h>
+#endif
+
+#include "pcre2_internal.h"
+
+/* The maximum remembered capturing brackets minimum. */
+
+#define MAX_CACHE_BACKREF 128
+
+/* Set a bit in the starting code unit bit map. */
+
+#define SET_BIT(c) re->start_bitmap[(c)/8] |= (1u << ((c)&7))
+
+/* Returns from set_start_bits() */
+
+enum { SSB_FAIL, SSB_DONE, SSB_CONTINUE, SSB_UNKNOWN, SSB_TOODEEP };
+
+
+/*************************************************
+*   Find the minimum subject length for a group  *
+*************************************************/
+
+/* Scan a parenthesized group and compute the minimum length of subject that
+is needed to match it. This is a lower bound; it does not mean there is a
+string of that length that matches. In UTF mode, the result is in characters
+rather than code units. The field in a compiled pattern for storing the minimum
+length is 16-bits long (on the grounds that anything longer than that is
+pathological), so we give up when we reach that amount. This also means that
+integer overflow for really crazy patterns cannot happen.
+
+Backreference minimum lengths are cached to speed up multiple references. This
+function is called only when the highest back reference in the pattern is less
+than or equal to MAX_CACHE_BACKREF, which is one less than the size of the
+caching vector. The zeroth element contains the number of the highest set
+value.
+
+Arguments:
+  re              compiled pattern block
+  code            pointer to start of group (the bracket)
+  startcode       pointer to start of the whole pattern's code
+  utf             UTF flag
+  recurses        chain of recurse_check to catch mutual recursion
+  countptr        pointer to call count (to catch over complexity)
+  backref_cache   vector for caching back references.
+
+This function is no longer called when the pattern contains (*ACCEPT); however,
+the old code for returning -1 is retained, just in case.
+
+Returns:   the minimum length
+           -1 \C in UTF-8 mode
+              or (*ACCEPT)
+              or pattern too complicated
+           -2 internal error (missing capturing bracket)
+           -3 internal error (opcode not listed)
+*/
+
+static int
+find_minlength(const pcre2_real_code *re, PCRE2_SPTR code,
+  PCRE2_SPTR startcode, BOOL utf, recurse_check *recurses, int *countptr,
+  int *backref_cache)
+{
+int length = -1;
+int branchlength = 0;
+int prev_cap_recno = -1;
+int prev_cap_d = 0;
+int prev_recurse_recno = -1;
+int prev_recurse_d = 0;
+uint32_t once_fudge = 0;
+BOOL had_recurse = FALSE;
+BOOL dupcapused = (re->flags & PCRE2_DUPCAPUSED) != 0;
+PCRE2_SPTR nextbranch = code + GET(code, 1);
+PCRE2_UCHAR *cc = (PCRE2_UCHAR *)code + 1 + LINK_SIZE;
+recurse_check this_recurse;
+
+/* If this is a "could be empty" group, its minimum length is 0. */
+
+if (*code >= OP_SBRA && *code <= OP_SCOND) return 0;
+
+/* Skip over capturing bracket number */
+
+if (*code == OP_CBRA || *code == OP_CBRAPOS) cc += IMM2_SIZE;
+
+/* A large and/or complex regex can take too long to process. */
+
+if ((*countptr)++ > 1000) return -1;
+
+/* Scan along the opcodes for this branch. If we get to the end of the branch,
+check the length against that of the other branches. If the accumulated length
+passes 16-bits, reset to that value and skip the rest of the branch. */
+
+for (;;)
+  {
+  int d, min, recno;
+  PCRE2_UCHAR op, *cs, *ce;
+
+  if (branchlength >= UINT16_MAX)
+    {
+    branchlength = UINT16_MAX;
+    cc = (PCRE2_UCHAR *)nextbranch;
+    }
+
+  op = *cc;
+  switch (op)
+    {
+    case OP_COND:
+    case OP_SCOND:
+
+    /* If there is only one branch in a condition, the implied branch has zero
+    length, so we don't add anything. This covers the DEFINE "condition"
+    automatically. If there are two branches we can treat it the same as any
+    other non-capturing subpattern. */
+
+    cs = cc + GET(cc, 1);
+    if (*cs != OP_ALT)
+      {
+      cc = cs + 1 + LINK_SIZE;
+      break;
+      }
+    goto PROCESS_NON_CAPTURE;
+
+    case OP_BRA:
+    /* There's a special case of OP_BRA, when it is wrapped round a repeated
+    OP_RECURSE. We'd like to process the latter at this level so that
+    remembering the value works for repeated cases. So we do nothing, but
+    set a fudge value to skip over the OP_KET after the recurse. */
+
+    if (cc[1+LINK_SIZE] == OP_RECURSE && cc[2*(1+LINK_SIZE)] == OP_KET)
+      {
+      once_fudge = 1 + LINK_SIZE;
+      cc += 1 + LINK_SIZE;
+      break;
+      }
+    /* Fall through */
+
+    case OP_ONCE:
+    case OP_SCRIPT_RUN:
+    case OP_SBRA:
+    case OP_BRAPOS:
+    case OP_SBRAPOS:
+    PROCESS_NON_CAPTURE:
+    d = find_minlength(re, cc, startcode, utf, recurses, countptr,
+      backref_cache);
+    if (d < 0) return d;
+    branchlength += d;
+    do cc += GET(cc, 1); while (*cc == OP_ALT);
+    cc += 1 + LINK_SIZE;
+    break;
+
+    /* To save time for repeated capturing subpatterns, we remember the
+    length of the previous one. Unfortunately we can't do the same for
+    the unnumbered ones above. Nor can we do this if (?| is present in the
+    pattern because captures with the same number are not then identical. */
+
+    case OP_CBRA:
+    case OP_SCBRA:
+    case OP_CBRAPOS:
+    case OP_SCBRAPOS:
+    recno = (int)GET2(cc, 1+LINK_SIZE);
+    if (dupcapused || recno != prev_cap_recno)
+      {
+      prev_cap_recno = recno;
+      prev_cap_d = find_minlength(re, cc, startcode, utf, recurses, countptr,
+        backref_cache);
+      if (prev_cap_d < 0) return prev_cap_d;
+      }
+    branchlength += prev_cap_d;
+    do cc += GET(cc, 1); while (*cc == OP_ALT);
+    cc += 1 + LINK_SIZE;
+    break;
+
+    /* ACCEPT makes things far too complicated; we have to give up. In fact,
+    from 10.34 onwards, if a pattern contains (*ACCEPT), this function is not
+    used. However, leave the code in place, just in case. */
+
+    case OP_ACCEPT:
+    case OP_ASSERT_ACCEPT:
+    return -1;
+
+    /* Reached end of a branch; if it's a ket it is the end of a nested
+    call. If it's ALT it is an alternation in a nested call. If it is END it's
+    the end of the outer call. All can be handled by the same code. If the
+    length of any branch is zero, there is no need to scan any subsequent
+    branches. */
+
+    case OP_ALT:
+    case OP_KET:
+    case OP_KETRMAX:
+    case OP_KETRMIN:
+    case OP_KETRPOS:
+    case OP_END:
+    if (length < 0 || (!had_recurse && branchlength < length))
+      length = branchlength;
+    if (op != OP_ALT || length == 0) return length;
+    nextbranch = cc + GET(cc, 1);
+    cc += 1 + LINK_SIZE;
+    branchlength = 0;
+    had_recurse = FALSE;
+    break;
+
+    /* Skip over assertive subpatterns */
+
+    case OP_ASSERT:
+    case OP_ASSERT_NOT:
+    case OP_ASSERTBACK:
+    case OP_ASSERTBACK_NOT:
+    case OP_ASSERT_NA:
+    case OP_ASSERTBACK_NA:
+    do cc += GET(cc, 1); while (*cc == OP_ALT);
+    /* Fall through */
+
+    /* Skip over things that don't match chars */
+
+    case OP_REVERSE:
+    case OP_CREF:
+    case OP_DNCREF:
+    case OP_RREF:
+    case OP_DNRREF:
+    case OP_FALSE:
+    case OP_TRUE:
+    case OP_CALLOUT:
+    case OP_SOD:
+    case OP_SOM:
+    case OP_EOD:
+    case OP_EODN:
+    case OP_CIRC:
+    case OP_CIRCM:
+    case OP_DOLL:
+    case OP_DOLLM:
+    case OP_NOT_WORD_BOUNDARY:
+    case OP_WORD_BOUNDARY:
+    cc += PRIV(OP_lengths)[*cc];
+    break;
+
+    case OP_CALLOUT_STR:
+    cc += GET(cc, 1 + 2*LINK_SIZE);
+    break;
+
+    /* Skip over a subpattern that has a {0} or {0,x} quantifier */
+
+    case OP_BRAZERO:
+    case OP_BRAMINZERO:
+    case OP_BRAPOSZERO:
+    case OP_SKIPZERO:
+    cc += PRIV(OP_lengths)[*cc];
+    do cc += GET(cc, 1); while (*cc == OP_ALT);
+    cc += 1 + LINK_SIZE;
+    break;
+
+    /* Handle literal characters and + repetitions */
+
+    case OP_CHAR:
+    case OP_CHARI:
+    case OP_NOT:
+    case OP_NOTI:
+    case OP_PLUS:
+    case OP_PLUSI:
+    case OP_MINPLUS:
+    case OP_MINPLUSI:
+    case OP_POSPLUS:
+    case OP_POSPLUSI:
+    case OP_NOTPLUS:
+    case OP_NOTPLUSI:
+    case OP_NOTMINPLUS:
+    case OP_NOTMINPLUSI:
+    case OP_NOTPOSPLUS:
+    case OP_NOTPOSPLUSI:
+    branchlength++;
+    cc += 2;
+#ifdef SUPPORT_UNICODE
+    if (utf && HAS_EXTRALEN(cc[-1])) cc += GET_EXTRALEN(cc[-1]);
+#endif
+    break;
+
+    case OP_TYPEPLUS:
+    case OP_TYPEMINPLUS:
+    case OP_TYPEPOSPLUS:
+    branchlength++;
+    cc += (cc[1] == OP_PROP || cc[1] == OP_NOTPROP)? 4 : 2;
+    break;
+
+    /* Handle exact repetitions. The count is already in characters, but we
+    may need to skip over a multibyte character in UTF mode.  */
+
+    case OP_EXACT:
+    case OP_EXACTI:
+    case OP_NOTEXACT:
+    case OP_NOTEXACTI:
+    branchlength += GET2(cc,1);
+    cc += 2 + IMM2_SIZE;
+#ifdef SUPPORT_UNICODE
+    if (utf && HAS_EXTRALEN(cc[-1])) cc += GET_EXTRALEN(cc[-1]);
+#endif
+    break;
+
+    case OP_TYPEEXACT:
+    branchlength += GET2(cc,1);
+    cc += 2 + IMM2_SIZE + ((cc[1 + IMM2_SIZE] == OP_PROP
+      || cc[1 + IMM2_SIZE] == OP_NOTPROP)? 2 : 0);
+    break;
+
+    /* Handle single-char non-literal matchers */
+
+    case OP_PROP:
+    case OP_NOTPROP:
+    cc += 2;
+    /* Fall through */
+
+    case OP_NOT_DIGIT:
+    case OP_DIGIT:
+    case OP_NOT_WHITESPACE:
+    case OP_WHITESPACE:
+    case OP_NOT_WORDCHAR:
+    case OP_WORDCHAR:
+    case OP_ANY:
+    case OP_ALLANY:
+    case OP_EXTUNI:
+    case OP_HSPACE:
+    case OP_NOT_HSPACE:
+    case OP_VSPACE:
+    case OP_NOT_VSPACE:
+    branchlength++;
+    cc++;
+    break;
+
+    /* "Any newline" might match two characters, but it also might match just
+    one. */
+
+    case OP_ANYNL:
+    branchlength += 1;
+    cc++;
+    break;
+
+    /* The single-byte matcher means we can't proceed in UTF mode. (In
+    non-UTF mode \C will actually be turned into OP_ALLANY, so won't ever
+    appear, but leave the code, just in case.) */
+
+    case OP_ANYBYTE:
+#ifdef SUPPORT_UNICODE
+    if (utf) return -1;
+#endif
+    branchlength++;
+    cc++;
+    break;
+
+    /* For repeated character types, we have to test for \p and \P, which have
+    an extra two bytes of parameters. */
+
+    case OP_TYPESTAR:
+    case OP_TYPEMINSTAR:
+    case OP_TYPEQUERY:
+    case OP_TYPEMINQUERY:
+    case OP_TYPEPOSSTAR:
+    case OP_TYPEPOSQUERY:
+    if (cc[1] == OP_PROP || cc[1] == OP_NOTPROP) cc += 2;
+    cc += PRIV(OP_lengths)[op];
+    break;
+
+    case OP_TYPEUPTO:
+    case OP_TYPEMINUPTO:
+    case OP_TYPEPOSUPTO:
+    if (cc[1 + IMM2_SIZE] == OP_PROP
+      || cc[1 + IMM2_SIZE] == OP_NOTPROP) cc += 2;
+    cc += PRIV(OP_lengths)[op];
+    break;
+
+    /* Check a class for variable quantification */
+
+    case OP_CLASS:
+    case OP_NCLASS:
+#ifdef SUPPORT_WIDE_CHARS
+    case OP_XCLASS:
+    /* The original code caused an unsigned overflow in 64 bit systems,
+    so now we use a conditional statement. */
+    if (op == OP_XCLASS)
+      cc += GET(cc, 1);
+    else
+      cc += PRIV(OP_lengths)[OP_CLASS];
+#else
+    cc += PRIV(OP_lengths)[OP_CLASS];
+#endif
+
+    switch (*cc)
+      {
+      case OP_CRPLUS:
+      case OP_CRMINPLUS:
+      case OP_CRPOSPLUS:
+      branchlength++;
+      /* Fall through */
+
+      case OP_CRSTAR:
+      case OP_CRMINSTAR:
+      case OP_CRQUERY:
+      case OP_CRMINQUERY:
+      case OP_CRPOSSTAR:
+      case OP_CRPOSQUERY:
+      cc++;
+      break;
+
+      case OP_CRRANGE:
+      case OP_CRMINRANGE:
+      case OP_CRPOSRANGE:
+      branchlength += GET2(cc,1);
+      cc += 1 + 2 * IMM2_SIZE;
+      break;
+
+      default:
+      branchlength++;
+      break;
+      }
+    break;
+
+    /* Backreferences and subroutine calls (OP_RECURSE) are treated in the same
+    way: we find the minimum length for the subpattern. A recursion
+    (backreference or subroutine) causes an a flag to be set that causes the
+    length of this branch to be ignored. The logic is that a recursion can only
+    make sense if there is another alternative that stops the recursing. That
+    will provide the minimum length (when no recursion happens).
+
+    If PCRE2_MATCH_UNSET_BACKREF is set, a backreference to an unset bracket
+    matches an empty string (by default it causes a matching failure), so in
+    that case we must set the minimum length to zero.
+
+    For backreferenes, if duplicate numbers are present in the pattern we check
+    for a reference to a duplicate. If it is, we don't know which version will
+    be referenced, so we have to set the minimum length to zero. */
+
+    /* Duplicate named pattern back reference. */
+
+    case OP_DNREF:
+    case OP_DNREFI:
+    if (!dupcapused && (re->overall_options & PCRE2_MATCH_UNSET_BACKREF) == 0)
+      {
+      int count = GET2(cc, 1+IMM2_SIZE);
+      PCRE2_UCHAR *slot =
+        (PCRE2_UCHAR *)((uint8_t *)re + sizeof(pcre2_real_code)) +
+          GET2(cc, 1) * re->name_entry_size;
+
+      d = INT_MAX;
+
+      /* Scan all groups with the same name; find the shortest. */
+
+      while (count-- > 0)
+        {
+        int dd, i;
+        recno = GET2(slot, 0);
+
+        if (recno <= backref_cache[0] && backref_cache[recno] >= 0)
+          dd = backref_cache[recno];
+        else
+          {
+          ce = cs = (PCRE2_UCHAR *)PRIV(find_bracket)(startcode, utf, recno);
+          if (cs == NULL) return -2;
+          do ce += GET(ce, 1); while (*ce == OP_ALT);
+
+          dd = 0;
+          if (!dupcapused ||
+              (PCRE2_UCHAR *)PRIV(find_bracket)(ce, utf, recno) == NULL)
+            {
+            if (cc > cs && cc < ce)    /* Simple recursion */
+              {
+              had_recurse = TRUE;
+              }
+            else
+              {
+              recurse_check *r = recurses;
+              for (r = recurses; r != NULL; r = r->prev)
+                if (r->group == cs) break;
+              if (r != NULL)           /* Mutual recursion */
+                {
+                had_recurse = TRUE;
+                }
+              else
+                {
+                this_recurse.prev = recurses;  /* No recursion */
+                this_recurse.group = cs;
+                dd = find_minlength(re, cs, startcode, utf, &this_recurse,
+                  countptr, backref_cache);
+                if (dd < 0) return dd;
+                }
+              }
+            }
+
+          backref_cache[recno] = dd;
+          for (i = backref_cache[0] + 1; i < recno; i++) backref_cache[i] = -1;
+          backref_cache[0] = recno;
+          }
+
+        if (dd < d) d = dd;
+        if (d <= 0) break;    /* No point looking at any more */
+        slot += re->name_entry_size;
+        }
+      }
+    else d = 0;
+    cc += 1 + 2*IMM2_SIZE;
+    goto REPEAT_BACK_REFERENCE;
+
+    /* Single back reference by number. References by name are converted to by
+    number when there is no duplication. */
+
+    case OP_REF:
+    case OP_REFI:
+    recno = GET2(cc, 1);
+    if (recno <= backref_cache[0] && backref_cache[recno] >= 0)
+      d = backref_cache[recno];
+    else
+      {
+      int i;
+      d = 0;
+
+      if ((re->overall_options & PCRE2_MATCH_UNSET_BACKREF) == 0)
+        {
+        ce = cs = (PCRE2_UCHAR *)PRIV(find_bracket)(startcode, utf, recno);
+        if (cs == NULL) return -2;
+        do ce += GET(ce, 1); while (*ce == OP_ALT);
+
+        if (!dupcapused ||
+            (PCRE2_UCHAR *)PRIV(find_bracket)(ce, utf, recno) == NULL)
+          {
+          if (cc > cs && cc < ce)    /* Simple recursion */
+            {
+            had_recurse = TRUE;
+            }
+          else
+            {
+            recurse_check *r = recurses;
+            for (r = recurses; r != NULL; r = r->prev) if (r->group == cs) break;
+            if (r != NULL)           /* Mutual recursion */
+              {
+              had_recurse = TRUE;
+              }
+            else                     /* No recursion */
+              {
+              this_recurse.prev = recurses;
+              this_recurse.group = cs;
+              d = find_minlength(re, cs, startcode, utf, &this_recurse, countptr,
+                backref_cache);
+              if (d < 0) return d;
+              }
+            }
+          }
+        }
+
+      backref_cache[recno] = d;
+      for (i = backref_cache[0] + 1; i < recno; i++) backref_cache[i] = -1;
+      backref_cache[0] = recno;
+      }
+
+    cc += 1 + IMM2_SIZE;
+
+    /* Handle repeated back references */
+
+    REPEAT_BACK_REFERENCE:
+    switch (*cc)
+      {
+      case OP_CRSTAR:
+      case OP_CRMINSTAR:
+      case OP_CRQUERY:
+      case OP_CRMINQUERY:
+      case OP_CRPOSSTAR:
+      case OP_CRPOSQUERY:
+      min = 0;
+      cc++;
+      break;
+
+      case OP_CRPLUS:
+      case OP_CRMINPLUS:
+      case OP_CRPOSPLUS:
+      min = 1;
+      cc++;
+      break;
+
+      case OP_CRRANGE:
+      case OP_CRMINRANGE:
+      case OP_CRPOSRANGE:
+      min = GET2(cc, 1);
+      cc += 1 + 2 * IMM2_SIZE;
+      break;
+
+      default:
+      min = 1;
+      break;
+      }
+
+     /* Take care not to overflow: (1) min and d are ints, so check that their
+     product is not greater than INT_MAX. (2) branchlength is limited to
+     UINT16_MAX (checked at the top of the loop). */
+
+    if ((d > 0 && (INT_MAX/d) < min) || UINT16_MAX - branchlength < min*d)
+      branchlength = UINT16_MAX;
+    else branchlength += min * d;
+    break;
+
+    /* Recursion always refers to the first occurrence of a subpattern with a
+    given number. Therefore, we can always make use of caching, even when the
+    pattern contains multiple subpatterns with the same number. */
+
+    case OP_RECURSE:
+    cs = ce = (PCRE2_UCHAR *)startcode + GET(cc, 1);
+    recno = GET2(cs, 1+LINK_SIZE);
+    if (recno == prev_recurse_recno)
+      {
+      branchlength += prev_recurse_d;
+      }
+    else
+      {
+      do ce += GET(ce, 1); while (*ce == OP_ALT);
+      if (cc > cs && cc < ce)    /* Simple recursion */
+        had_recurse = TRUE;
+      else
+        {
+        recurse_check *r = recurses;
+        for (r = recurses; r != NULL; r = r->prev) if (r->group == cs) break;
+        if (r != NULL)          /* Mutual recursion */
+          had_recurse = TRUE;
+        else
+          {
+          this_recurse.prev = recurses;
+          this_recurse.group = cs;
+          prev_recurse_d = find_minlength(re, cs, startcode, utf, &this_recurse,
+            countptr, backref_cache);
+          if (prev_recurse_d < 0) return prev_recurse_d;
+          prev_recurse_recno = recno;
+          branchlength += prev_recurse_d;
+          }
+        }
+      }
+    cc += 1 + LINK_SIZE + once_fudge;
+    once_fudge = 0;
+    break;
+
+    /* Anything else does not or need not match a character. We can get the
+    item's length from the table, but for those that can match zero occurrences
+    of a character, we must take special action for UTF-8 characters. As it
+    happens, the "NOT" versions of these opcodes are used at present only for
+    ASCII characters, so they could be omitted from this list. However, in
+    future that may change, so we include them here so as not to leave a
+    gotcha for a future maintainer. */
+
+    case OP_UPTO:
+    case OP_UPTOI:
+    case OP_NOTUPTO:
+    case OP_NOTUPTOI:
+    case OP_MINUPTO:
+    case OP_MINUPTOI:
+    case OP_NOTMINUPTO:
+    case OP_NOTMINUPTOI:
+    case OP_POSUPTO:
+    case OP_POSUPTOI:
+    case OP_NOTPOSUPTO:
+    case OP_NOTPOSUPTOI:
+
+    case OP_STAR:
+    case OP_STARI:
+    case OP_NOTSTAR:
+    case OP_NOTSTARI:
+    case OP_MINSTAR:
+    case OP_MINSTARI:
+    case OP_NOTMINSTAR:
+    case OP_NOTMINSTARI:
+    case OP_POSSTAR:
+    case OP_POSSTARI:
+    case OP_NOTPOSSTAR:
+    case OP_NOTPOSSTARI:
+
+    case OP_QUERY:
+    case OP_QUERYI:
+    case OP_NOTQUERY:
+    case OP_NOTQUERYI:
+    case OP_MINQUERY:
+    case OP_MINQUERYI:
+    case OP_NOTMINQUERY:
+    case OP_NOTMINQUERYI:
+    case OP_POSQUERY:
+    case OP_POSQUERYI:
+    case OP_NOTPOSQUERY:
+    case OP_NOTPOSQUERYI:
+
+    cc += PRIV(OP_lengths)[op];
+#ifdef SUPPORT_UNICODE
+    if (utf && HAS_EXTRALEN(cc[-1])) cc += GET_EXTRALEN(cc[-1]);
+#endif
+    break;
+
+    /* Skip these, but we need to add in the name length. */
+
+    case OP_MARK:
+    case OP_COMMIT_ARG:
+    case OP_PRUNE_ARG:
+    case OP_SKIP_ARG:
+    case OP_THEN_ARG:
+    cc += PRIV(OP_lengths)[op] + cc[1];
+    break;
+
+    /* The remaining opcodes are just skipped over. */
+
+    case OP_CLOSE:
+    case OP_COMMIT:
+    case OP_FAIL:
+    case OP_PRUNE:
+    case OP_SET_SOM:
+    case OP_SKIP:
+    case OP_THEN:
+    cc += PRIV(OP_lengths)[op];
+    break;
+
+    /* This should not occur: we list all opcodes explicitly so that when
+    new ones get added they are properly considered. */
+
+    default:
+    return -3;
+    }
+  }
+/* Control never gets here */
+}
+
+
+
+/*************************************************
+*      Set a bit and maybe its alternate case    *
+*************************************************/
+
+/* Given a character, set its first code unit's bit in the table, and also the
+corresponding bit for the other version of a letter if we are caseless.
+
+Arguments:
+  re            points to the regex block
+  p             points to the first code unit of the character
+  caseless      TRUE if caseless
+  utf           TRUE for UTF mode
+  ucp           TRUE for UCP mode
+
+Returns:        pointer after the character
+*/
+
+static PCRE2_SPTR
+set_table_bit(pcre2_real_code *re, PCRE2_SPTR p, BOOL caseless, BOOL utf,
+  BOOL ucp)
+{
+uint32_t c = *p++;   /* First code unit */
+
+(void)utf;           /* Stop compiler warnings when UTF not supported */
+(void)ucp;
+
+/* In 16-bit and 32-bit modes, code units greater than 0xff set the bit for
+0xff. */
+
+#if PCRE2_CODE_UNIT_WIDTH != 8
+if (c > 0xff) SET_BIT(0xff); else
+#endif
+
+SET_BIT(c);
+
+/* In UTF-8 or UTF-16 mode, pick up the remaining code units in order to find
+the end of the character, even when caseless. */
+
+#ifdef SUPPORT_UNICODE
+if (utf)
+  {
+#if PCRE2_CODE_UNIT_WIDTH == 8
+  if (c >= 0xc0) GETUTF8INC(c, p);
+#elif PCRE2_CODE_UNIT_WIDTH == 16
+  if ((c & 0xfc00) == 0xd800) GETUTF16INC(c, p);
+#endif
+  }
+#endif  /* SUPPORT_UNICODE */
+
+/* If caseless, handle the other case of the character. */
+
+if (caseless)
+  {
+#ifdef SUPPORT_UNICODE
+  if (utf || ucp)
+    {
+    c = UCD_OTHERCASE(c);
+#if PCRE2_CODE_UNIT_WIDTH == 8
+    if (utf)
+      {
+      PCRE2_UCHAR buff[6];
+      (void)PRIV(ord2utf)(c, buff);
+      SET_BIT(buff[0]);
+      }
+    else if (c < 256) SET_BIT(c);
+#else  /* 16-bit or 32-bit mode */
+    if (c > 0xff) SET_BIT(0xff); else SET_BIT(c);
+#endif
+    }
+
+  else
+#endif  /* SUPPORT_UNICODE */
+
+  /* Not UTF or UCP */
+
+  if (MAX_255(c)) SET_BIT(re->tables[fcc_offset + c]);
+  }
+
+return p;
+}
+
+
+
+/*************************************************
+*     Set bits for a positive character type     *
+*************************************************/
+
+/* This function sets starting bits for a character type. In UTF-8 mode, we can
+only do a direct setting for bytes less than 128, as otherwise there can be
+confusion with bytes in the middle of UTF-8 characters. In a "traditional"
+environment, the tables will only recognize ASCII characters anyway, but in at
+least one Windows environment, some higher bytes bits were set in the tables.
+So we deal with that case by considering the UTF-8 encoding.
+
+Arguments:
+  re             the regex block
+  cbit type      the type of character wanted
+  table_limit    32 for non-UTF-8; 16 for UTF-8
+
+Returns:         nothing
+*/
+
+static void
+set_type_bits(pcre2_real_code *re, int cbit_type, unsigned int table_limit)
+{
+uint32_t c;
+for (c = 0; c < table_limit; c++)
+  re->start_bitmap[c] |= re->tables[c+cbits_offset+cbit_type];
+#if defined SUPPORT_UNICODE && PCRE2_CODE_UNIT_WIDTH == 8
+if (table_limit == 32) return;
+for (c = 128; c < 256; c++)
+  {
+  if ((re->tables[cbits_offset + c/8] & (1u << (c&7))) != 0)
+    {
+    PCRE2_UCHAR buff[6];
+    (void)PRIV(ord2utf)(c, buff);
+    SET_BIT(buff[0]);
+    }
+  }
+#endif  /* UTF-8 */
+}
+
+
+/*************************************************
+*     Set bits for a negative character type     *
+*************************************************/
+
+/* This function sets starting bits for a negative character type such as \D.
+In UTF-8 mode, we can only do a direct setting for bytes less than 128, as
+otherwise there can be confusion with bytes in the middle of UTF-8 characters.
+Unlike in the positive case, where we can set appropriate starting bits for
+specific high-valued UTF-8 characters, in this case we have to set the bits for
+all high-valued characters. The lowest is 0xc2, but we overkill by starting at
+0xc0 (192) for simplicity.
+
+Arguments:
+  re             the regex block
+  cbit type      the type of character wanted
+  table_limit    32 for non-UTF-8; 16 for UTF-8
+
+Returns:         nothing
+*/
+
+static void
+set_nottype_bits(pcre2_real_code *re, int cbit_type, unsigned int table_limit)
+{
+uint32_t c;
+for (c = 0; c < table_limit; c++)
+  re->start_bitmap[c] |= (uint8_t)(~(re->tables[c+cbits_offset+cbit_type]));
+#if defined SUPPORT_UNICODE && PCRE2_CODE_UNIT_WIDTH == 8
+if (table_limit != 32) for (c = 24; c < 32; c++) re->start_bitmap[c] = 0xff;
+#endif
+}
+
+
+
+/*************************************************
+*      Create bitmap of starting code units      *
+*************************************************/
+
+/* This function scans a compiled unanchored expression recursively and
+attempts to build a bitmap of the set of possible starting code units whose
+values are less than 256. In 16-bit and 32-bit mode, values above 255 all cause
+the 255 bit to be set. When calling set[_not]_type_bits() in UTF-8 (sic) mode
+we pass a value of 16 rather than 32 as the final argument. (See comments in
+those functions for the reason.)
+
+The SSB_CONTINUE return is useful for parenthesized groups in patterns such as
+(a*)b where the group provides some optional starting code units but scanning
+must continue at the outer level to find at least one mandatory code unit. At
+the outermost level, this function fails unless the result is SSB_DONE.
+
+We restrict recursion (for nested groups) to 1000 to avoid stack overflow
+issues.
+
+Arguments:
+  re           points to the compiled regex block
+  code         points to an expression
+  utf          TRUE if in UTF mode
+  ucp          TRUE if in UCP mode
+  depthptr     pointer to recurse depth
+
+Returns:       SSB_FAIL     => Failed to find any starting code units
+               SSB_DONE     => Found mandatory starting code units
+               SSB_CONTINUE => Found optional starting code units
+               SSB_UNKNOWN  => Hit an unrecognized opcode
+               SSB_TOODEEP  => Recursion is too deep
+*/
+
+static int
+set_start_bits(pcre2_real_code *re, PCRE2_SPTR code, BOOL utf, BOOL ucp,
+  int *depthptr)
+{
+uint32_t c;
+int yield = SSB_DONE;
+
+#if defined SUPPORT_UNICODE && PCRE2_CODE_UNIT_WIDTH == 8
+int table_limit = utf? 16:32;
+#else
+int table_limit = 32;
+#endif
+
+*depthptr += 1;
+if (*depthptr > 1000) return SSB_TOODEEP;
+
+do
+  {
+  BOOL try_next = TRUE;
+  PCRE2_SPTR tcode = code + 1 + LINK_SIZE;
+
+  if (*code == OP_CBRA || *code == OP_SCBRA ||
+      *code == OP_CBRAPOS || *code == OP_SCBRAPOS) tcode += IMM2_SIZE;
+
+  while (try_next)    /* Loop for items in this branch */
+    {
+    int rc;
+    uint8_t *classmap = NULL;
+#ifdef SUPPORT_WIDE_CHARS
+    PCRE2_UCHAR xclassflags;
+#endif
+
+    switch(*tcode)
+      {
+      /* If we reach something we don't understand, it means a new opcode has
+      been created that hasn't been added to this function. Hopefully this
+      problem will be discovered during testing. */
+
+      default:
+      return SSB_UNKNOWN;
+
+      /* Fail for a valid opcode that implies no starting bits. */
+
+      case OP_ACCEPT:
+      case OP_ASSERT_ACCEPT:
+      case OP_ALLANY:
+      case OP_ANY:
+      case OP_ANYBYTE:
+      case OP_CIRCM:
+      case OP_CLOSE:
+      case OP_COMMIT:
+      case OP_COMMIT_ARG:
+      case OP_COND:
+      case OP_CREF:
+      case OP_FALSE:
+      case OP_TRUE:
+      case OP_DNCREF:
+      case OP_DNREF:
+      case OP_DNREFI:
+      case OP_DNRREF:
+      case OP_DOLL:
+      case OP_DOLLM:
+      case OP_END:
+      case OP_EOD:
+      case OP_EODN:
+      case OP_EXTUNI:
+      case OP_FAIL:
+      case OP_MARK:
+      case OP_NOT:
+      case OP_NOTEXACT:
+      case OP_NOTEXACTI:
+      case OP_NOTI:
+      case OP_NOTMINPLUS:
+      case OP_NOTMINPLUSI:
+      case OP_NOTMINQUERY:
+      case OP_NOTMINQUERYI:
+      case OP_NOTMINSTAR:
+      case OP_NOTMINSTARI:
+      case OP_NOTMINUPTO:
+      case OP_NOTMINUPTOI:
+      case OP_NOTPLUS:
+      case OP_NOTPLUSI:
+      case OP_NOTPOSPLUS:
+      case OP_NOTPOSPLUSI:
+      case OP_NOTPOSQUERY:
+      case OP_NOTPOSQUERYI:
+      case OP_NOTPOSSTAR:
+      case OP_NOTPOSSTARI:
+      case OP_NOTPOSUPTO:
+      case OP_NOTPOSUPTOI:
+      case OP_NOTPROP:
+      case OP_NOTQUERY:
+      case OP_NOTQUERYI:
+      case OP_NOTSTAR:
+      case OP_NOTSTARI:
+      case OP_NOTUPTO:
+      case OP_NOTUPTOI:
+      case OP_NOT_HSPACE:
+      case OP_NOT_VSPACE:
+      case OP_PRUNE:
+      case OP_PRUNE_ARG:
+      case OP_RECURSE:
+      case OP_REF:
+      case OP_REFI:
+      case OP_REVERSE:
+      case OP_RREF:
+      case OP_SCOND:
+      case OP_SET_SOM:
+      case OP_SKIP:
+      case OP_SKIP_ARG:
+      case OP_SOD:
+      case OP_SOM:
+      case OP_THEN:
+      case OP_THEN_ARG:
+      return SSB_FAIL;
+
+      /* OP_CIRC happens only at the start of an anchored branch (multiline ^
+      uses OP_CIRCM). Skip over it. */
+
+      case OP_CIRC:
+      tcode += PRIV(OP_lengths)[OP_CIRC];
+      break;
+
+      /* A "real" property test implies no starting bits, but the fake property
+      PT_CLIST identifies a list of characters. These lists are short, as they
+      are used for characters with more than one "other case", so there is no
+      point in recognizing them for OP_NOTPROP. */
+
+      case OP_PROP:
+      if (tcode[1] != PT_CLIST) return SSB_FAIL;
+        {
+        const uint32_t *p = PRIV(ucd_caseless_sets) + tcode[2];
+        while ((c = *p++) < NOTACHAR)
+          {
+#if defined SUPPORT_UNICODE && PCRE2_CODE_UNIT_WIDTH == 8
+          if (utf)
+            {
+            PCRE2_UCHAR buff[6];
+            (void)PRIV(ord2utf)(c, buff);
+            c = buff[0];
+            }
+#endif
+          if (c > 0xff) SET_BIT(0xff); else SET_BIT(c);
+          }
+        }
+      try_next = FALSE;
+      break;
+
+      /* We can ignore word boundary tests. */
+
+      case OP_WORD_BOUNDARY:
+      case OP_NOT_WORD_BOUNDARY:
+      tcode++;
+      break;
+
+      /* If we hit a bracket or a positive lookahead assertion, recurse to set
+      bits from within the subpattern. If it can't find anything, we have to
+      give up. If it finds some mandatory character(s), we are done for this
+      branch. Otherwise, carry on scanning after the subpattern. */
+
+      case OP_BRA:
+      case OP_SBRA:
+      case OP_CBRA:
+      case OP_SCBRA:
+      case OP_BRAPOS:
+      case OP_SBRAPOS:
+      case OP_CBRAPOS:
+      case OP_SCBRAPOS:
+      case OP_ONCE:
+      case OP_SCRIPT_RUN:
+      case OP_ASSERT:
+      case OP_ASSERT_NA:
+      rc = set_start_bits(re, tcode, utf, ucp, depthptr);
+      if (rc == SSB_DONE)
+        {
+        try_next = FALSE;
+        }
+      else if (rc == SSB_CONTINUE)
+        {
+        do tcode += GET(tcode, 1); while (*tcode == OP_ALT);
+        tcode += 1 + LINK_SIZE;
+        }
+      else return rc;   /* FAIL, UNKNOWN, or TOODEEP */
+      break;
+
+      /* If we hit ALT or KET, it means we haven't found anything mandatory in
+      this branch, though we might have found something optional. For ALT, we
+      continue with the next alternative, but we have to arrange that the final
+      result from subpattern is SSB_CONTINUE rather than SSB_DONE. For KET,
+      return SSB_CONTINUE: if this is the top level, that indicates failure,
+      but after a nested subpattern, it causes scanning to continue. */
+
+      case OP_ALT:
+      yield = SSB_CONTINUE;
+      try_next = FALSE;
+      break;
+
+      case OP_KET:
+      case OP_KETRMAX:
+      case OP_KETRMIN:
+      case OP_KETRPOS:
+      return SSB_CONTINUE;
+
+      /* Skip over callout */
+
+      case OP_CALLOUT:
+      tcode += PRIV(OP_lengths)[OP_CALLOUT];
+      break;
+
+      case OP_CALLOUT_STR:
+      tcode += GET(tcode, 1 + 2*LINK_SIZE);
+      break;
+
+      /* Skip over lookbehind and negative lookahead assertions */
+
+      case OP_ASSERT_NOT:
+      case OP_ASSERTBACK:
+      case OP_ASSERTBACK_NOT:
+      case OP_ASSERTBACK_NA:
+      do tcode += GET(tcode, 1); while (*tcode == OP_ALT);
+      tcode += 1 + LINK_SIZE;
+      break;
+
+      /* BRAZERO does the bracket, but carries on. */
+
+      case OP_BRAZERO:
+      case OP_BRAMINZERO:
+      case OP_BRAPOSZERO:
+      rc = set_start_bits(re, ++tcode, utf, ucp, depthptr);
+      if (rc == SSB_FAIL || rc == SSB_UNKNOWN || rc == SSB_TOODEEP) return rc;
+      do tcode += GET(tcode,1); while (*tcode == OP_ALT);
+      tcode += 1 + LINK_SIZE;
+      break;
+
+      /* SKIPZERO skips the bracket. */
+
+      case OP_SKIPZERO:
+      tcode++;
+      do tcode += GET(tcode,1); while (*tcode == OP_ALT);
+      tcode += 1 + LINK_SIZE;
+      break;
+
+      /* Single-char * or ? sets the bit and tries the next item */
+
+      case OP_STAR:
+      case OP_MINSTAR:
+      case OP_POSSTAR:
+      case OP_QUERY:
+      case OP_MINQUERY:
+      case OP_POSQUERY:
+      tcode = set_table_bit(re, tcode + 1, FALSE, utf, ucp);
+      break;
+
+      case OP_STARI:
+      case OP_MINSTARI:
+      case OP_POSSTARI:
+      case OP_QUERYI:
+      case OP_MINQUERYI:
+      case OP_POSQUERYI:
+      tcode = set_table_bit(re, tcode + 1, TRUE, utf, ucp);
+      break;
+
+      /* Single-char upto sets the bit and tries the next */
+
+      case OP_UPTO:
+      case OP_MINUPTO:
+      case OP_POSUPTO:
+      tcode = set_table_bit(re, tcode + 1 + IMM2_SIZE, FALSE, utf, ucp);
+      break;
+
+      case OP_UPTOI:
+      case OP_MINUPTOI:
+      case OP_POSUPTOI:
+      tcode = set_table_bit(re, tcode + 1 + IMM2_SIZE, TRUE, utf, ucp);
+      break;
+
+      /* At least one single char sets the bit and stops */
+
+      case OP_EXACT:
+      tcode += IMM2_SIZE;
+      /* Fall through */
+      case OP_CHAR:
+      case OP_PLUS:
+      case OP_MINPLUS:
+      case OP_POSPLUS:
+      (void)set_table_bit(re, tcode + 1, FALSE, utf, ucp);
+      try_next = FALSE;
+      break;
+
+      case OP_EXACTI:
+      tcode += IMM2_SIZE;
+      /* Fall through */
+      case OP_CHARI:
+      case OP_PLUSI:
+      case OP_MINPLUSI:
+      case OP_POSPLUSI:
+      (void)set_table_bit(re, tcode + 1, TRUE, utf, ucp);
+      try_next = FALSE;
+      break;
+
+      /* Special spacing and line-terminating items. These recognize specific
+      lists of characters. The difference between VSPACE and ANYNL is that the
+      latter can match the two-character CRLF sequence, but that is not
+      relevant for finding the first character, so their code here is
+      identical. */
+
+      case OP_HSPACE:
+      SET_BIT(CHAR_HT);
+      SET_BIT(CHAR_SPACE);
+
+      /* For the 16-bit and 32-bit libraries (which can never be EBCDIC), set
+      the bits for 0xA0 and for code units >= 255, independently of UTF. */
+
+#if PCRE2_CODE_UNIT_WIDTH != 8
+      SET_BIT(0xA0);
+      SET_BIT(0xFF);
+#else
+      /* For the 8-bit library in UTF-8 mode, set the bits for the first code
+      units of horizontal space characters. */
+
+#ifdef SUPPORT_UNICODE
+      if (utf)
+        {
+        SET_BIT(0xC2);  /* For U+00A0 */
+        SET_BIT(0xE1);  /* For U+1680, U+180E */
+        SET_BIT(0xE2);  /* For U+2000 - U+200A, U+202F, U+205F */
+        SET_BIT(0xE3);  /* For U+3000 */
+        }
+      else
+#endif
+      /* For the 8-bit library not in UTF-8 mode, set the bit for 0xA0, unless
+      the code is EBCDIC. */
+        {
+#ifndef EBCDIC
+        SET_BIT(0xA0);
+#endif  /* Not EBCDIC */
+        }
+#endif  /* 8-bit support */
+
+      try_next = FALSE;
+      break;
+
+      case OP_ANYNL:
+      case OP_VSPACE:
+      SET_BIT(CHAR_LF);
+      SET_BIT(CHAR_VT);
+      SET_BIT(CHAR_FF);
+      SET_BIT(CHAR_CR);
+
+      /* For the 16-bit and 32-bit libraries (which can never be EBCDIC), set
+      the bits for NEL and for code units >= 255, independently of UTF. */
+
+#if PCRE2_CODE_UNIT_WIDTH != 8
+      SET_BIT(CHAR_NEL);
+      SET_BIT(0xFF);
+#else
+      /* For the 8-bit library in UTF-8 mode, set the bits for the first code
+      units of vertical space characters. */
+
+#ifdef SUPPORT_UNICODE
+      if (utf)
+        {
+        SET_BIT(0xC2);  /* For U+0085 (NEL) */
+        SET_BIT(0xE2);  /* For U+2028, U+2029 */
+        }
+      else
+#endif
+      /* For the 8-bit library not in UTF-8 mode, set the bit for NEL. */
+        {
+        SET_BIT(CHAR_NEL);
+        }
+#endif  /* 8-bit support */
+
+      try_next = FALSE;
+      break;
+
+      /* Single character types set the bits and stop. Note that if PCRE2_UCP
+      is set, we do not see these opcodes because \d etc are converted to
+      properties. Therefore, these apply in the case when only characters less
+      than 256 are recognized to match the types. */
+
+      case OP_NOT_DIGIT:
+      set_nottype_bits(re, cbit_digit, table_limit);
+      try_next = FALSE;
+      break;
+
+      case OP_DIGIT:
+      set_type_bits(re, cbit_digit, table_limit);
+      try_next = FALSE;
+      break;
+
+      case OP_NOT_WHITESPACE:
+      set_nottype_bits(re, cbit_space, table_limit);
+      try_next = FALSE;
+      break;
+
+      case OP_WHITESPACE:
+      set_type_bits(re, cbit_space, table_limit);
+      try_next = FALSE;
+      break;
+
+      case OP_NOT_WORDCHAR:
+      set_nottype_bits(re, cbit_word, table_limit);
+      try_next = FALSE;
+      break;
+
+      case OP_WORDCHAR:
+      set_type_bits(re, cbit_word, table_limit);
+      try_next = FALSE;
+      break;
+
+      /* One or more character type fudges the pointer and restarts, knowing
+      it will hit a single character type and stop there. */
+
+      case OP_TYPEPLUS:
+      case OP_TYPEMINPLUS:
+      case OP_TYPEPOSPLUS:
+      tcode++;
+      break;
+
+      case OP_TYPEEXACT:
+      tcode += 1 + IMM2_SIZE;
+      break;
+
+      /* Zero or more repeats of character types set the bits and then
+      try again. */
+
+      case OP_TYPEUPTO:
+      case OP_TYPEMINUPTO:
+      case OP_TYPEPOSUPTO:
+      tcode += IMM2_SIZE;  /* Fall through */
+
+      case OP_TYPESTAR:
+      case OP_TYPEMINSTAR:
+      case OP_TYPEPOSSTAR:
+      case OP_TYPEQUERY:
+      case OP_TYPEMINQUERY:
+      case OP_TYPEPOSQUERY:
+      switch(tcode[1])
+        {
+        default:
+        case OP_ANY:
+        case OP_ALLANY:
+        return SSB_FAIL;
+
+        case OP_HSPACE:
+        SET_BIT(CHAR_HT);
+        SET_BIT(CHAR_SPACE);
+
+        /* For the 16-bit and 32-bit libraries (which can never be EBCDIC), set
+        the bits for 0xA0 and for code units >= 255, independently of UTF. */
+
+#if PCRE2_CODE_UNIT_WIDTH != 8
+        SET_BIT(0xA0);
+        SET_BIT(0xFF);
+#else
+        /* For the 8-bit library in UTF-8 mode, set the bits for the first code
+        units of horizontal space characters. */
+
+#ifdef SUPPORT_UNICODE
+        if (utf)
+          {
+          SET_BIT(0xC2);  /* For U+00A0 */
+          SET_BIT(0xE1);  /* For U+1680, U+180E */
+          SET_BIT(0xE2);  /* For U+2000 - U+200A, U+202F, U+205F */
+          SET_BIT(0xE3);  /* For U+3000 */
+          }
+        else
+#endif
+        /* For the 8-bit library not in UTF-8 mode, set the bit for 0xA0, unless
+        the code is EBCDIC. */
+          {
+#ifndef EBCDIC
+          SET_BIT(0xA0);
+#endif  /* Not EBCDIC */
+          }
+#endif  /* 8-bit support */
+        break;
+
+        case OP_ANYNL:
+        case OP_VSPACE:
+        SET_BIT(CHAR_LF);
+        SET_BIT(CHAR_VT);
+        SET_BIT(CHAR_FF);
+        SET_BIT(CHAR_CR);
+
+        /* For the 16-bit and 32-bit libraries (which can never be EBCDIC), set
+        the bits for NEL and for code units >= 255, independently of UTF. */
+
+#if PCRE2_CODE_UNIT_WIDTH != 8
+        SET_BIT(CHAR_NEL);
+        SET_BIT(0xFF);
+#else
+        /* For the 8-bit library in UTF-8 mode, set the bits for the first code
+        units of vertical space characters. */
+
+#ifdef SUPPORT_UNICODE
+        if (utf)
+          {
+          SET_BIT(0xC2);  /* For U+0085 (NEL) */
+          SET_BIT(0xE2);  /* For U+2028, U+2029 */
+          }
+        else
+#endif
+        /* For the 8-bit library not in UTF-8 mode, set the bit for NEL. */
+          {
+          SET_BIT(CHAR_NEL);
+          }
+#endif  /* 8-bit support */
+        break;
+
+        case OP_NOT_DIGIT:
+        set_nottype_bits(re, cbit_digit, table_limit);
+        break;
+
+        case OP_DIGIT:
+        set_type_bits(re, cbit_digit, table_limit);
+        break;
+
+        case OP_NOT_WHITESPACE:
+        set_nottype_bits(re, cbit_space, table_limit);
+        break;
+
+        case OP_WHITESPACE:
+        set_type_bits(re, cbit_space, table_limit);
+        break;
+
+        case OP_NOT_WORDCHAR:
+        set_nottype_bits(re, cbit_word, table_limit);
+        break;
+
+        case OP_WORDCHAR:
+        set_type_bits(re, cbit_word, table_limit);
+        break;
+        }
+
+      tcode += 2;
+      break;
+
+      /* Extended class: if there are any property checks, or if this is a
+      negative XCLASS without a map, give up. If there are no property checks,
+      there must be wide characters on the XCLASS list, because otherwise an
+      XCLASS would not have been created. This means that code points >= 255
+      are potential starters. In the UTF-8 case we can scan them and set bits
+      for the relevant leading bytes. */
+
+#ifdef SUPPORT_WIDE_CHARS
+      case OP_XCLASS:
+      xclassflags = tcode[1 + LINK_SIZE];
+      if ((xclassflags & XCL_HASPROP) != 0 ||
+          (xclassflags & (XCL_MAP|XCL_NOT)) == XCL_NOT)
+        return SSB_FAIL;
+
+      /* We have a positive XCLASS or a negative one without a map. Set up the
+      map pointer if there is one, and fall through. */
+
+      classmap = ((xclassflags & XCL_MAP) == 0)? NULL :
+        (uint8_t *)(tcode + 1 + LINK_SIZE + 1);
+
+      /* In UTF-8 mode, scan the character list and set bits for leading bytes,
+      then jump to handle the map. */
+
+#if PCRE2_CODE_UNIT_WIDTH == 8
+      if (utf && (xclassflags & XCL_NOT) == 0)
+        {
+        PCRE2_UCHAR b, e;
+        PCRE2_SPTR p = tcode + 1 + LINK_SIZE + 1 + ((classmap == NULL)? 0:32);
+        tcode += GET(tcode, 1);
+
+        for (;;) switch (*p++)
+          {
+          case XCL_SINGLE:
+          b = *p++;
+          while ((*p & 0xc0) == 0x80) p++;
+          re->start_bitmap[b/8] |= (1u << (b&7));
+          break;
+
+          case XCL_RANGE:
+          b = *p++;
+          while ((*p & 0xc0) == 0x80) p++;
+          e = *p++;
+          while ((*p & 0xc0) == 0x80) p++;
+          for (; b <= e; b++)
+            re->start_bitmap[b/8] |= (1u << (b&7));
+          break;
+
+          case XCL_END:
+          goto HANDLE_CLASSMAP;
+
+          default:
+          return SSB_UNKNOWN;   /* Internal error, should not occur */
+          }
+        }
+#endif  /* SUPPORT_UNICODE && PCRE2_CODE_UNIT_WIDTH == 8 */
+#endif  /* SUPPORT_WIDE_CHARS */
+
+      /* It seems that the fall through comment must be outside the #ifdef if
+      it is to avoid the gcc compiler warning. */
+
+      /* Fall through */
+
+      /* Enter here for a negative non-XCLASS. In the 8-bit library, if we are
+      in UTF mode, any byte with a value >= 0xc4 is a potentially valid starter
+      because it starts a character with a value > 255. In 8-bit non-UTF mode,
+      there is no difference between CLASS and NCLASS. In all other wide
+      character modes, set the 0xFF bit to indicate code units >= 255. */
+
+      case OP_NCLASS:
+#if defined SUPPORT_UNICODE && PCRE2_CODE_UNIT_WIDTH == 8
+      if (utf)
+        {
+        re->start_bitmap[24] |= 0xf0;            /* Bits for 0xc4 - 0xc8 */
+        memset(re->start_bitmap+25, 0xff, 7);    /* Bits for 0xc9 - 0xff */
+        }
+#elif PCRE2_CODE_UNIT_WIDTH != 8
+      SET_BIT(0xFF);                             /* For characters >= 255 */
+#endif
+      /* Fall through */
+
+      /* Enter here for a positive non-XCLASS. If we have fallen through from
+      an XCLASS, classmap will already be set; just advance the code pointer.
+      Otherwise, set up classmap for a a non-XCLASS and advance past it. */
+
+      case OP_CLASS:
+      if (*tcode == OP_XCLASS) tcode += GET(tcode, 1); else
+        {
+        classmap = (uint8_t *)(++tcode);
+        tcode += 32 / sizeof(PCRE2_UCHAR);
+        }
+
+      /* When wide characters are supported, classmap may be NULL. In UTF-8
+      (sic) mode, the bits in a class bit map correspond to character values,
+      not to byte values. However, the bit map we are constructing is for byte
+      values. So we have to do a conversion for characters whose code point is
+      greater than 127. In fact, there are only two possible starting bytes for
+      characters in the range 128 - 255. */
+
+#if defined SUPPORT_WIDE_CHARS && PCRE2_CODE_UNIT_WIDTH == 8
+      HANDLE_CLASSMAP:
+#endif
+      if (classmap != NULL)
+        {
+#if defined SUPPORT_UNICODE && PCRE2_CODE_UNIT_WIDTH == 8
+        if (utf)
+          {
+          for (c = 0; c < 16; c++) re->start_bitmap[c] |= classmap[c];
+          for (c = 128; c < 256; c++)
+            {
+            if ((classmap[c/8] & (1u << (c&7))) != 0)
+              {
+              int d = (c >> 6) | 0xc0;                 /* Set bit for this starter */
+              re->start_bitmap[d/8] |= (1u << (d&7));  /* and then skip on to the */
+              c = (c & 0xc0) + 0x40 - 1;               /* next relevant character. */
+              }
+            }
+          }
+        else
+#endif
+        /* In all modes except UTF-8, the two bit maps are compatible. */
+
+          {
+          for (c = 0; c < 32; c++) re->start_bitmap[c] |= classmap[c];
+          }
+        }
+
+      /* Act on what follows the class. For a zero minimum repeat, continue;
+      otherwise stop processing. */
+
+      switch (*tcode)
+        {
+        case OP_CRSTAR:
+        case OP_CRMINSTAR:
+        case OP_CRQUERY:
+        case OP_CRMINQUERY:
+        case OP_CRPOSSTAR:
+        case OP_CRPOSQUERY:
+        tcode++;
+        break;
+
+        case OP_CRRANGE:
+        case OP_CRMINRANGE:
+        case OP_CRPOSRANGE:
+        if (GET2(tcode, 1) == 0) tcode += 1 + 2 * IMM2_SIZE;
+          else try_next = FALSE;
+        break;
+
+        default:
+        try_next = FALSE;
+        break;
+        }
+      break; /* End of class handling case */
+      }      /* End of switch for opcodes */
+    }        /* End of try_next loop */
+
+  code += GET(code, 1);   /* Advance to next branch */
+  }
+while (*code == OP_ALT);
+
+return yield;
+}
+
+
+
+/*************************************************
+*          Study a compiled expression           *
+*************************************************/
+
+/* This function is handed a compiled expression that it must study to produce
+information that will speed up the matching.
+
+Argument:
+  re       points to the compiled expression
+
+Returns:   0 normally; non-zero should never normally occur
+           1 unknown opcode in set_start_bits
+           2 missing capturing bracket
+           3 unknown opcode in find_minlength
+*/
+
+int
+PRIV(study)(pcre2_real_code *re)
+{
+int count = 0;
+PCRE2_UCHAR *code;
+BOOL utf = (re->overall_options & PCRE2_UTF) != 0;
+BOOL ucp = (re->overall_options & PCRE2_UCP) != 0;
+
+/* Find start of compiled code */
+
+code = (PCRE2_UCHAR *)((uint8_t *)re + sizeof(pcre2_real_code)) +
+  re->name_entry_size * re->name_count;
+
+/* For a pattern that has a first code unit, or a multiline pattern that
+matches only at "line start", there is no point in seeking a list of starting
+code units. */
+
+if ((re->flags & (PCRE2_FIRSTSET|PCRE2_STARTLINE)) == 0)
+  {
+  int depth = 0;
+  int rc = set_start_bits(re, code, utf, ucp, &depth);
+  if (rc == SSB_UNKNOWN) return 1;
+
+  /* If a list of starting code units was set up, scan the list to see if only
+  one or two were listed. Having only one listed is rare because usually a
+  single starting code unit will have been recognized and PCRE2_FIRSTSET set.
+  If two are listed, see if they are caseless versions of the same character;
+  if so we can replace the list with a caseless first code unit. This gives
+  better performance and is plausibly worth doing for patterns such as [Ww]ord
+  or (word|WORD). */
+
+  if (rc == SSB_DONE)
+    {
+    int i;
+    int a = -1;
+    int b = -1;
+    uint8_t *p = re->start_bitmap;
+    uint32_t flags = PCRE2_FIRSTMAPSET;
+
+    for (i = 0; i < 256; p++, i += 8)
+      {
+      uint8_t x = *p;
+      if (x != 0)
+        {
+        int c;
+        uint8_t y = x & (~x + 1);   /* Least significant bit */
+        if (y != x) goto DONE;      /* More than one bit set */
+
+        /* In the 16-bit and 32-bit libraries, the bit for 0xff means "0xff and
+        all wide characters", so we cannot use it here. */
+
+#if PCRE2_CODE_UNIT_WIDTH != 8
+        if (i == 248 && x == 0x80) goto DONE;
+#endif
+
+        /* Compute the character value */
+
+        c = i;
+        switch (x)
+          {
+          case 1:   break;
+          case 2:   c += 1; break;  case 4:  c += 2; break;
+          case 8:   c += 3; break;  case 16: c += 4; break;
+          case 32:  c += 5; break;  case 64: c += 6; break;
+          case 128: c += 7; break;
+          }
+
+        /* c contains the code unit value, in the range 0-255. In 8-bit UTF
+        mode, only values < 128 can be used. In all the other cases, c is a
+        character value. */
+
+#if PCRE2_CODE_UNIT_WIDTH == 8
+        if (utf && c > 127) goto DONE;
+#endif
+        if (a < 0) a = c;   /* First one found, save in a */
+        else if (b < 0)     /* Second one found */
+          {
+          int d = TABLE_GET((unsigned int)c, re->tables + fcc_offset, c);
+
+#ifdef SUPPORT_UNICODE
+          if (utf || ucp)
+            {
+            if (UCD_CASESET(c) != 0) goto DONE;     /* Multiple case set */
+            if (c > 127) d = UCD_OTHERCASE(c);
+            }
+#endif  /* SUPPORT_UNICODE */
+
+          if (d != a) goto DONE;   /* Not the other case of a */
+          b = c;                   /* Save second in b */
+          }
+        else goto DONE;   /* More than two characters found */
+        }
+      }
+
+    /* Replace the start code unit bits with a first code unit, but only if it
+    is not the same as a required later code unit. This is because a search for
+    a required code unit starts after an explicit first code unit, but at a
+    code unit found from the bitmap. Patterns such as /a*a/ don't work
+    if both the start unit and required unit are the same. */
+
+    if (a >= 0 &&
+        (
+        (re->flags & PCRE2_LASTSET) == 0 ||
+          (
+          re->last_codeunit != (uint32_t)a &&
+          (b < 0 || re->last_codeunit != (uint32_t)b)
+          )
+        ))
+      {
+      re->first_codeunit = a;
+      flags = PCRE2_FIRSTSET;
+      if (b >= 0) flags |= PCRE2_FIRSTCASELESS;
+      }
+
+    DONE:
+    re->flags |= flags;
+    }
+  }
+
+/* Find the minimum length of subject string. If the pattern can match an empty
+string, the minimum length is already known. If the pattern contains (*ACCEPT)
+all bets are off, and we don't even try to find a minimum length. If there are
+more back references than the size of the vector we are going to cache them in,
+do nothing. A pattern that complicated will probably take a long time to
+analyze and may in any case turn out to be too complicated. Note that back
+reference minima are held as 16-bit numbers. */
+
+if ((re->flags & (PCRE2_MATCH_EMPTY|PCRE2_HASACCEPT)) == 0 &&
+     re->top_backref <= MAX_CACHE_BACKREF)
+  {
+  int min;
+  int backref_cache[MAX_CACHE_BACKREF+1];
+  backref_cache[0] = 0;    /* Highest one that is set */
+  min = find_minlength(re, code, code, utf, NULL, &count, backref_cache);
+  switch(min)
+    {
+    case -1:  /* \C in UTF mode or over-complex regex */
+    break;    /* Leave minlength unchanged (will be zero) */
+
+    case -2:
+    return 2; /* missing capturing bracket */
+
+    case -3:
+    return 3; /* unrecognized opcode */
+
+    default:
+    re->minlength = (min > UINT16_MAX)? UINT16_MAX : min;
+    break;
+    }
+  }
+
+return 0;
+}
+
+/* End of pcre2_study.c */