len = 0; \
} else { \
len = 1; \
- uvc = _to_fold_latin1( (U8) *uc, foldbuf, &foldlen, 1); \
+ uvc = _to_fold_latin1( (U8) *uc, foldbuf, &foldlen, FOLD_FLAGS_FULL); \
skiplen = UNISKIP(uvc); \
foldlen -= skiplen; \
scan = foldbuf + skiplen; \
* this file makes sure that in EXACTFU nodes, the sharp s gets folded to
* 'ss', even if the pattern isn't UTF-8. This avoids the issues
* described in the next item.
- * 4) A problem remains for the sharp s in EXACTF nodes. Whether it matches
- * 'ss' or not is not knowable at compile time. It will match iff the
- * target string is in UTF-8, unlike the EXACTFU nodes, where it always
- * matches; and the EXACTFL and EXACTFA nodes where it never does. Thus
- * it can't be folded to "ss" at compile time, unlike EXACTFU does (as
- * described in item 3). An assumption that the optimizer part of
- * regexec.c (probably unwittingly) makes is that a character in the
- * pattern corresponds to at most a single character in the target string.
- * (And I do mean character, and not byte here, unlike other parts of the
- * documentation that have never been updated to account for multibyte
- * Unicode.) This assumption is wrong only in this case, as all other
- * cases are either 1-1 folds when no UTF-8 is involved; or is true by
- * virtue of having this file pre-fold UTF-8 patterns. I'm
- * reluctant to try to change this assumption, so instead the code punts.
- * This routine examines EXACTF nodes for the sharp s, and returns a
- * boolean indicating whether or not the node is an EXACTF node that
- * contains a sharp s. When it is true, the caller sets a flag that later
- * causes the optimizer in this file to not set values for the floating
- * and fixed string lengths, and thus avoids the optimizer code in
- * regexec.c that makes the invalid assumption. Thus, there is no
- * optimization based on string lengths for EXACTF nodes that contain the
- * sharp s. This only happens for /id rules (which means the pattern
- * isn't in UTF-8).
+ * 4) A problem remains for the sharp s in EXACTF and EXACTFA nodes when the
+ * pattern isn't in UTF-8. (BTW, there cannot be an EXACTF node with a
+ * UTF-8 pattern.) An assumption that the optimizer part of regexec.c
+ * (probably unwittingly, in Perl_regexec_flags()) makes is that a
+ * character in the pattern corresponds to at most a single character in
+ * the target string. (And I do mean character, and not byte here, unlike
+ * other parts of the documentation that have never been updated to
+ * account for multibyte Unicode.) sharp s in EXACTF nodes can match the
+ * two character string 'ss'; in EXACTFA nodes it can match
+ * "\x{17F}\x{17F}". These violate the assumption, and they are the only
+ * instances where it is violated. I'm reluctant to try to change the
+ * assumption, as the code involved is impenetrable to me (khw), so
+ * instead the code here punts. This routine examines (when the pattern
+ * isn't UTF-8) EXACTF and EXACTFA nodes for the sharp s, and returns a
+ * boolean indicating whether or not the node contains a sharp s. When it
+ * is true, the caller sets a flag that later causes the optimizer in this
+ * file to not set values for the floating and fixed string lengths, and
+ * thus avoids the optimizer code in regexec.c that makes the invalid
+ * assumption. Thus, there is no optimization based on string lengths for
+ * non-UTF8-pattern EXACTF and EXACTFA nodes that contain the sharp s.
+ * (The reason the assumption is wrong only in these two cases is that all
+ * other non-UTF-8 folds are 1-1; and, for UTF-8 patterns, we pre-fold all
+ * other folds to their expanded versions. We can't prefold sharp s to
+ * 'ss' in EXACTF nodes because we don't know at compile time if it
+ * actually matches 'ss' or not. It will match iff the target string is
+ * in UTF-8, unlike the EXACTFU nodes, where it always matches; and
+ * EXACTFA and EXACTFL where it never does. In an EXACTFA node in a UTF-8
+ * pattern, sharp s is folded to "\x{17F}\x{17F}, avoiding the problem;
+ * but in a non-UTF8 pattern, folding it to that above-Latin1 string would
+ * require the pattern to be forced into UTF-8, the overhead of which we
+ * want to avoid.)
*/
#define JOIN_EXACT(scan,min_subtract,has_exactf_sharp_s, flags) \
next_iteration: ;
}
}
- else if (OP(scan) != EXACTFL && OP(scan) != EXACTFA) {
+ else if (OP(scan) == EXACTFA) {
- /* Here, the pattern is not UTF-8. Look for the multi-char folds
- * that are all ASCII. As in the above case, EXACTFL and EXACTFA
- * nodes can't have multi-char folds to this range (and there are
- * no existing ones in the upper latin1 range). In the EXACTF
- * case we look also for the sharp s, which can be in the final
+ /* Non-UTF-8 pattern, EXACTFA node. There can't be a multi-char
+ * fold to the ASCII range (and there are no existing ones in the
+ * upper latin1 range). But, as outlined in the comments preceding
+ * this function, we need to flag any occurrences of the sharp s */
+ while (s < s_end) {
+ if (*s == LATIN_SMALL_LETTER_SHARP_S) {
+ *has_exactf_sharp_s = TRUE;
+ break;
+ }
+ s++;
+ continue;
+ }
+ }
+ else if (OP(scan) != EXACTFL) {
+
+ /* Non-UTF-8 pattern, not EXACTFA nor EXACTFL node. Look for the
+ * multi-char folds that are all Latin1. (This code knows that
+ * there are no current multi-char folds possible with EXACTFL,
+ * relying on fold_grind.t to catch any errors if the very unlikely
+ * event happens that some get added in future Unicode versions.)
+ * As explained in the comments preceding this function, we look
+ * also for the sharp s in EXACTF nodes; it can be in the final
* position. Otherwise we can stop looking 1 byte earlier because
* have to find at least two characters for a multi-fold */
const U8* upper = (OP(scan) == EXACTF) ? s_end : s_end -1;
goto parse_named_seq;
} }
num = atoi(RExC_parse);
- if (isg && num == 0)
- vFAIL("Reference to invalid group 0");
+ if (isg && num == 0) {
+ if (*RExC_parse == '0') {
+ vFAIL("Reference to invalid group 0");
+ }
+ else {
+ vFAIL("Unterminated \\g... pattern");
+ }
+ }
if (isrel) {
num = RExC_npar - num;
if (num < 1)
char * const parse_start = RExC_parse - 1; /* MJD */
while (isDIGIT(*RExC_parse))
RExC_parse++;
- if (parse_start == RExC_parse - 1)
- vFAIL("Unterminated \\g... pattern");
if (hasbrace) {
if (*RExC_parse != '}')
vFAIL("Unterminated \\g{...} pattern");
*(s++) = (char) ender;
maybe_exact &= ! IS_IN_SOME_FOLD_L1(ender);
}
- else {
+ else { /* UTF */
/* Prime the casefolded buffer. Locale rules, which apply
* only to code points < 256, aren't known until execution,
https://perl5.git.perl.org / perl5.git / blobdiff