+HV*
+Perl__swash_inversion_hash(pTHX_ SV* const swash)
+{
+
+ /* Subject to change or removal. For use only in one place in regcomp.c.
+ * Can't be used on a property that is subject to user override, as it
+ * relies on the value of SPECIALS in the swash which would be set by
+ * utf8_heavy.pl to the hash in the non-overriden file, and hence is not set
+ * for overridden properties
+ *
+ * Returns a hash which is the inversion and closure of a swash mapping.
+ * For example, consider the input lines:
+ * 004B 006B
+ * 004C 006C
+ * 212A 006B
+ *
+ * The returned hash would have two keys, the utf8 for 006B and the utf8 for
+ * 006C. The value for each key is an array. For 006C, the array would
+ * have a two elements, the utf8 for itself, and for 004C. For 006B, there
+ * would be three elements in its array, the utf8 for 006B, 004B and 212A.
+ *
+ * Essentially, for any code point, it gives all the code points that map to
+ * it, or the list of 'froms' for that point.
+ *
+ * Currently it ignores any additions or deletions from other swashes,
+ * looking at just the main body of the swash, and if there are SPECIALS
+ * in the swash, at that hash
+ *
+ * The specials hash can be extra code points, and most likely consists of
+ * maps from single code points to multiple ones (each expressed as a string
+ * of utf8 characters). This function currently returns only 1-1 mappings.
+ * However consider this possible input in the specials hash:
+ * "\xEF\xAC\x85" => "\x{0073}\x{0074}", # U+FB05 => 0073 0074
+ * "\xEF\xAC\x86" => "\x{0073}\x{0074}", # U+FB06 => 0073 0074
+ *
+ * Both FB05 and FB06 map to the same multi-char sequence, which we don't
+ * currently handle. But it also means that FB05 and FB06 are equivalent in
+ * a 1-1 mapping which we should handle, and this relationship may not be in
+ * the main table. Therefore this function examines all the multi-char
+ * sequences and adds the 1-1 mappings that come out of that. */
+
+ U8 *l, *lend;
+ STRLEN lcur;
+ HV *const hv = MUTABLE_HV(SvRV(swash));
+
+ /* The string containing the main body of the table */
+ SV** const listsvp = hv_fetchs(hv, "LIST", FALSE);
+
+ SV** const typesvp = hv_fetchs(hv, "TYPE", FALSE);
+ SV** const bitssvp = hv_fetchs(hv, "BITS", FALSE);
+ SV** const nonesvp = hv_fetchs(hv, "NONE", FALSE);
+ /*SV** const extssvp = hv_fetchs(hv, "EXTRAS", FALSE);*/
+ const U8* const typestr = (U8*)SvPV_nolen(*typesvp);
+ const STRLEN bits = SvUV(*bitssvp);
+ const STRLEN octets = bits >> 3; /* if bits == 1, then octets == 0 */
+ const UV none = SvUV(*nonesvp);
+ SV **specials_p = hv_fetchs(hv, "SPECIALS", 0);
+
+ HV* ret = newHV();
+
+ PERL_ARGS_ASSERT__SWASH_INVERSION_HASH;
+
+ /* Must have at least 8 bits to get the mappings */
+ if (bits != 8 && bits != 16 && bits != 32) {
+ Perl_croak(aTHX_ "panic: swash_inversion_hash doesn't expect bits %"UVuf,
+ (UV)bits);
+ }
+
+ if (specials_p) { /* It might be "special" (sometimes, but not always, a
+ mapping to more than one character */
+
+ /* Construct an inverse mapping hash for the specials */
+ HV * const specials_hv = MUTABLE_HV(SvRV(*specials_p));
+ HV * specials_inverse = newHV();
+ char *char_from; /* the lhs of the map */
+ I32 from_len; /* its byte length */
+ char *char_to; /* the rhs of the map */
+ I32 to_len; /* its byte length */
+ SV *sv_to; /* and in a sv */
+ AV* from_list; /* list of things that map to each 'to' */
+
+ hv_iterinit(specials_hv);
+
+ /* The keys are the characters (in utf8) that map to the corresponding
+ * utf8 string value. Iterate through the list creating the inverse
+ * list. */
+ while ((sv_to = hv_iternextsv(specials_hv, &char_from, &from_len))) {
+ SV** listp;
+ if (! SvPOK(sv_to)) {
+ Perl_croak(aTHX_ "panic: value returned from hv_iternextsv() unexpectedly is not a string");
+ }
+ /*DEBUG_U(PerlIO_printf(Perl_debug_log, "Found mapping from %"UVXf", First char of to is %"UVXf"\n", utf8_to_uvchr((U8*) char_from, 0), utf8_to_uvchr((U8*) SvPVX(sv_to), 0)));*/
+
+ /* Each key in the inverse list is a mapped-to value, and the key's
+ * hash value is a list of the strings (each in utf8) that map to
+ * it. Those strings are all one character long */
+ if ((listp = hv_fetch(specials_inverse,
+ SvPVX(sv_to),
+ SvCUR(sv_to), 0)))
+ {
+ from_list = (AV*) *listp;
+ }
+ else { /* No entry yet for it: create one */
+ from_list = newAV();
+ if (! hv_store(specials_inverse,
+ SvPVX(sv_to),
+ SvCUR(sv_to),
+ (SV*) from_list, 0))
+ {
+ Perl_croak(aTHX_ "panic: hv_store() unexpectedly failed");
+ }
+ }
+
+ /* Here have the list associated with this 'to' (perhaps newly
+ * created and empty). Just add to it. Note that we ASSUME that
+ * the input is guaranteed to not have duplications, so we don't
+ * check for that. Duplications just slow down execution time. */
+ av_push(from_list, newSVpvn_utf8(char_from, from_len, TRUE));
+ }
+
+ /* Here, 'specials_inverse' contains the inverse mapping. Go through
+ * it looking for cases like the FB05/FB06 examples above. There would
+ * be an entry in the hash like
+ * 'st' => [ FB05, FB06 ]
+ * In this example we will create two lists that get stored in the
+ * returned hash, 'ret':
+ * FB05 => [ FB05, FB06 ]
+ * FB06 => [ FB05, FB06 ]
+ *
+ * Note that there is nothing to do if the array only has one element.
+ * (In the normal 1-1 case handled below, we don't have to worry about
+ * two lists, as everything gets tied to the single list that is
+ * generated for the single character 'to'. But here, we are omitting
+ * that list, ('st' in the example), so must have multiple lists.) */
+ while ((from_list = (AV *) hv_iternextsv(specials_inverse,
+ &char_to, &to_len)))
+ {
+ if (av_len(from_list) > 0) {
+ int i;
+
+ /* We iterate over all combinations of i,j to place each code
+ * point on each list */
+ for (i = 0; i <= av_len(from_list); i++) {
+ int j;
+ AV* i_list = newAV();
+ SV** entryp = av_fetch(from_list, i, FALSE);
+ if (entryp == NULL) {
+ Perl_croak(aTHX_ "panic: av_fetch() unexpectedly failed");
+ }
+ if (hv_fetch(ret, SvPVX(*entryp), SvCUR(*entryp), FALSE)) {
+ Perl_croak(aTHX_ "panic: unexpected entry for %s", SvPVX(*entryp));
+ }
+ if (! hv_store(ret, SvPVX(*entryp), SvCUR(*entryp),
+ (SV*) i_list, FALSE))
+ {
+ Perl_croak(aTHX_ "panic: hv_store() unexpectedly failed");
+ }
+
+ /* For debugging: UV u = utf8_to_uvchr((U8*) SvPVX(*entryp), 0);*/
+ for (j = 0; j <= av_len(from_list); j++) {
+ entryp = av_fetch(from_list, j, FALSE);
+ if (entryp == NULL) {
+ Perl_croak(aTHX_ "panic: av_fetch() unexpectedly failed");
+ }
+
+ /* When i==j this adds itself to the list */
+ av_push(i_list, newSVuv(utf8_to_uvchr(
+ (U8*) SvPVX(*entryp), 0)));
+ /*DEBUG_U(PerlIO_printf(Perl_debug_log, "Adding %"UVXf" to list for %"UVXf"\n", utf8_to_uvchr((U8*) SvPVX(*entryp), 0), u));*/
+ }
+ }
+ }
+ }
+ SvREFCNT_dec(specials_inverse); /* done with it */
+ } /* End of specials */
+
+ /* read $swash->{LIST} */
+ l = (U8*)SvPV(*listsvp, lcur);
+ lend = l + lcur;
+
+ /* Go through each input line */
+ while (l < lend) {
+ UV min, max, val;
+ UV inverse;
+ l = S_swash_scan_list_line(aTHX_ l, lend, &min, &max, &val,
+ cBOOL(octets), typestr);
+ if (l > lend) {
+ break;
+ }
+
+ /* Each element in the range is to be inverted */
+ for (inverse = min; inverse <= max; inverse++) {
+ AV* list;
+ SV** listp;
+ IV i;
+ bool found_key = FALSE;
+ bool found_inverse = FALSE;
+
+ /* The key is the inverse mapping */
+ char key[UTF8_MAXBYTES+1];
+ char* key_end = (char *) uvuni_to_utf8((U8*) key, val);
+ STRLEN key_len = key_end - key;
+
+ /* Get the list for the map */
+ if ((listp = hv_fetch(ret, key, key_len, FALSE))) {
+ list = (AV*) *listp;
+ }
+ else { /* No entry yet for it: create one */
+ list = newAV();
+ if (! hv_store(ret, key, key_len, (SV*) list, FALSE)) {
+ Perl_croak(aTHX_ "panic: hv_store() unexpectedly failed");
+ }
+ }
+
+ /* Look through list to see if this inverse mapping already is
+ * listed, or if there is a mapping to itself already */
+ for (i = 0; i <= av_len(list); i++) {
+ SV** entryp = av_fetch(list, i, FALSE);
+ SV* entry;
+ if (entryp == NULL) {
+ Perl_croak(aTHX_ "panic: av_fetch() unexpectedly failed");
+ }
+ entry = *entryp;
+ /*DEBUG_U(PerlIO_printf(Perl_debug_log, "list for %"UVXf" contains %"UVXf"\n", val, SvUV(entry)));*/
+ if (SvUV(entry) == val) {
+ found_key = TRUE;
+ }
+ if (SvUV(entry) == inverse) {
+ found_inverse = TRUE;
+ }
+
+ /* No need to continue searching if found everything we are
+ * looking for */
+ if (found_key && found_inverse) {
+ break;
+ }
+ }
+
+ /* Make sure there is a mapping to itself on the list */
+ if (! found_key) {
+ av_push(list, newSVuv(val));
+ /*DEBUG_U(PerlIO_printf(Perl_debug_log, "Adding %"UVXf" to list for %"UVXf"\n", val, val));*/
+ }
+
+
+ /* Simply add the value to the list */
+ if (! found_inverse) {
+ av_push(list, newSVuv(inverse));
+ /*DEBUG_U(PerlIO_printf(Perl_debug_log, "Adding %"UVXf" to list for %"UVXf"\n", inverse, val));*/
+ }
+
+ /* swash_get() increments the value of val for each element in the
+ * range. That makes more compact tables possible. You can
+ * express the capitalization, for example, of all consecutive
+ * letters with a single line: 0061\t007A\t0041 This maps 0061 to
+ * 0041, 0062 to 0042, etc. I (khw) have never understood 'none',
+ * and it's not documented; it appears to be used only in
+ * implementing tr//; I copied the semantics from swash_get(), just
+ * in case */
+ if (!none || val < none) {
+ ++val;
+ }
+ }
+ }
+
+ return ret;
+}
+
+SV*
+Perl__swash_to_invlist(pTHX_ SV* const swash)
+{
+
+ /* Subject to change or removal. For use only in one place in regcomp.c */
+
+ U8 *l, *lend;
+ char *loc;
+ STRLEN lcur;
+ HV *const hv = MUTABLE_HV(SvRV(swash));
+ UV elements = 0; /* Number of elements in the inversion list */
+ U8 empty[] = "";
+
+ /* The string containing the main body of the table */
+ SV** const listsvp = hv_fetchs(hv, "LIST", FALSE);
+ SV** const typesvp = hv_fetchs(hv, "TYPE", FALSE);
+ SV** const bitssvp = hv_fetchs(hv, "BITS", FALSE);
+ SV** const extssvp = hv_fetchs(hv, "EXTRAS", FALSE);
+ SV** const invert_it_svp = hv_fetchs(hv, "INVERT_IT", FALSE);
+
+ const U8* const typestr = (U8*)SvPV_nolen(*typesvp);
+ const STRLEN bits = SvUV(*bitssvp);
+ const STRLEN octets = bits >> 3; /* if bits == 1, then octets == 0 */
+ U8 *x, *xend;
+ STRLEN xcur;
+
+ SV* invlist;
+
+ PERL_ARGS_ASSERT__SWASH_TO_INVLIST;
+
+ /* read $swash->{LIST} */
+ if (SvPOK(*listsvp)) {
+ l = (U8*)SvPV(*listsvp, lcur);
+ }
+ else {
+ /* LIST legitimately doesn't contain a string during compilation phases
+ * of Perl itself, before the Unicode tables are generated. In this
+ * case, just fake things up by creating an empty list */
+ l = empty;
+ lcur = 0;
+ }
+ loc = (char *) l;
+ lend = l + lcur;
+
+ /* Scan the input to count the number of lines to preallocate array size
+ * based on worst possible case, which is each line in the input creates 2
+ * elements in the inversion list: 1) the beginning of a range in the list;
+ * 2) the beginning of a range not in the list. */
+ while ((loc = (strchr(loc, '\n'))) != NULL) {
+ elements += 2;
+ loc++;
+ }
+
+ /* If the ending is somehow corrupt and isn't a new line, add another
+ * element for the final range that isn't in the inversion list */
+ if (! (*lend == '\n' || (*lend == '\0' && *(lend - 1) == '\n'))) {
+ elements++;
+ }
+
+ invlist = _new_invlist(elements);
+
+ /* Now go through the input again, adding each range to the list */
+ while (l < lend) {
+ UV start, end;
+ UV val; /* Not used by this function */
+
+ l = S_swash_scan_list_line(aTHX_ l, lend, &start, &end, &val,
+ cBOOL(octets), typestr);
+
+ if (l > lend) {
+ break;
+ }
+
+ _append_range_to_invlist(invlist, start, end);
+ }
+
+ /* Invert if the data says it should be */
+ if (invert_it_svp && SvUV(*invert_it_svp)) {
+ _invlist_invert_prop(invlist);
+ }
+
+ /* This code is copied from swash_get()
+ * read $swash->{EXTRAS} */
+ x = (U8*)SvPV(*extssvp, xcur);
+ xend = x + xcur;
+ while (x < xend) {
+ STRLEN namelen;
+ U8 *namestr;
+ SV** othersvp;
+ HV* otherhv;
+ STRLEN otherbits;
+ SV **otherbitssvp, *other;
+ U8 *nl;
+
+ const U8 opc = *x++;
+ if (opc == '\n')
+ continue;
+
+ nl = (U8*)memchr(x, '\n', xend - x);
+
+ if (opc != '-' && opc != '+' && opc != '!' && opc != '&') {
+ if (nl) {
+ x = nl + 1; /* 1 is length of "\n" */
+ continue;
+ }
+ else {
+ x = xend; /* to EXTRAS' end at which \n is not found */
+ break;
+ }
+ }
+
+ namestr = x;
+ if (nl) {
+ namelen = nl - namestr;
+ x = nl + 1;
+ }
+ else {
+ namelen = xend - namestr;
+ x = xend;
+ }
+
+ othersvp = hv_fetch(hv, (char *)namestr, namelen, FALSE);
+ otherhv = MUTABLE_HV(SvRV(*othersvp));
+ otherbitssvp = hv_fetchs(otherhv, "BITS", FALSE);
+ otherbits = (STRLEN)SvUV(*otherbitssvp);
+
+ if (bits != otherbits || bits != 1) {
+ Perl_croak(aTHX_ "panic: _swash_to_invlist only operates on boolean properties");
+ }
+
+ /* The "other" swatch must be destroyed after. */
+ other = _swash_to_invlist((SV *)*othersvp);
+
+ /* End of code copied from swash_get() */
+ switch (opc) {
+ case '+':
+ _invlist_union(invlist, other, &invlist);
+ break;
+ case '!':
+ _invlist_invert(other);
+ _invlist_union(invlist, other, &invlist);
+ break;
+ case '-':
+ _invlist_subtract(invlist, other, &invlist);
+ break;
+ case '&':
+ _invlist_intersection(invlist, other, &invlist);
+ break;
+ default:
+ break;
+ }
+ sv_free(other); /* through with it! */
+ }
+
+ return invlist;
+}
+