regex: Remove FOLDCHAR regnode type

This node type hasn't been used since 5.14.0.  Instead an ANYOFV node
was generated where formerly a FOLDCHAR node would have been used.  The
ANYOFV was used because it already existed and was up-to-date, whereas
FOLDCHAR would have needed some bug fixes to adapt it, even though it
would be faster in execution than ANYOFV; so the code for it was
retained in case it was needed.

However, both these solutions were defective, and a previous commit has
changed things to a different type of solution entirely.  Thus FOLDCHAR
is obsolescent and can be removed, though the code in it was used as a
base for some of the new solutions.

4 files changed, 6 insertions, 48 deletions

diff --git a/regcomp.c b/regcomp.c
index d2085fc753..b880599b11 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -3944,18 +3944,6 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
 		data->longest = &(data->longest_float);
     	    }
 	}
-	else if (OP(scan) == FOLDCHAR) {
-	    int d = ARG(scan) == LATIN_SMALL_LETTER_SHARP_S ? 1 : 2;
-	    flags &= ~SCF_DO_STCLASS;
-            min += 1;
-            delta += d;
-            if (flags & SCF_DO_SUBSTR) {
-	        SCAN_COMMIT(pRExC_state,data,minlenp);	/* Cannot expect anything... */
-	        data->pos_min += 1;
-	        data->pos_delta += d;
-		data->longest = &(data->longest_float);
-	    }
-	}
 	else if (REGNODE_SIMPLE(OP(scan))) {
 	    int value = 0;
 
@@ -11976,8 +11964,6 @@ Perl_regprop(pTHX_ const regexp *prog, SV *sv, const regnode *o)
 			   SVfARG((MUTABLE_SV(progi->data->data[ ARG( o ) ]))));
     } else if (k == LOGICAL)
 	Perl_sv_catpvf(aTHX_ sv, "[%d]", o->flags);	/* 2: embedded, otherwise 1 */
-    else if (k == FOLDCHAR)
-	Perl_sv_catpvf(aTHX_ sv, "[0x%"UVXf"]", PTR2UV(ARG(o)) );
     else if (k == ANYOF) {
 	int i, rangestart = -1;
 	const U8 flags = ANYOF_FLAGS(o);
diff --git a/regcomp.sym b/regcomp.sym
index 9f7788d943..f0ee701991 100644
--- a/regcomp.sym
+++ b/regcomp.sym
@@ -217,8 +217,6 @@ NVERTWS     NVERTWS,    none 0 S  ; not vertical whitespace     (Perl 6)
 HORIZWS     HORIZWS,    none 0 S  ; horizontal whitespace       (Perl 6)
 NHORIZWS    NHORIZWS,   none 0 S  ; not horizontal whitespace   (Perl 6)
 
-FOLDCHAR    FOLDCHAR,   codepoint 1 ; codepoint with tricky case folding properties.
-
 
 # NEW STUFF SOMEWHERE ABOVE THIS LINE
 
diff --git a/regexec.c b/regexec.c
index 54cc0174b1..6bd8b20b60 100644
--- a/regexec.c
+++ b/regexec.c
@@ -5710,27 +5710,6 @@ NULL
             sayNO;
             /* NOTREACHED */
 #undef ST
-        case FOLDCHAR:
-            n = ARG(scan);
-            if ( n == (U32)what_len_TRICKYFOLD(locinput,utf8_target,ln) ) {
-                locinput += ln;
-            } else if ( LATIN_SMALL_LETTER_SHARP_S == n && !utf8_target && !UTF_PATTERN ) {
-                sayNO;
-            } else  {
-                U8 folded[UTF8_MAXBYTES_CASE+1];
-                STRLEN foldlen;
-                const char * const l = locinput;
-                char *e = PL_regeol;
-                to_uni_fold(n, folded, &foldlen);
-
-		if (! foldEQ_utf8((const char*) folded, 0,  foldlen, 1,
-                	       l, &e, 0,  utf8_target)) {
-                        sayNO;
-                }
-                locinput = e;
-            } 
-            nextchr = UCHARAT(locinput);  
-            break;
         case LNBREAK:
             if ((n=is_LNBREAK(locinput,utf8_target))) {
                 locinput += n;
diff --git a/regnodes.h b/regnodes.h
index 785ff1c9ca..994159342f 100644
--- a/regnodes.h
+++ b/regnodes.h
@@ -6,8 +6,8 @@
 
 /* Regops and State definitions */
 
-#define REGNODE_MAX           	113
-#define REGMATCH_STATE_MAX    	153
+#define REGNODE_MAX           	112
+#define REGMATCH_STATE_MAX    	152
 
 #define	END                   	0	/* 0000 End of program. */
 #define	SUCCEED               	1	/* 0x01 Return from a subroutine, basically. */
@@ -120,9 +120,8 @@
 #define	NVERTWS               	108	/* 0x6c not vertical whitespace     (Perl 6) */
 #define	HORIZWS               	109	/* 0x6d horizontal whitespace       (Perl 6) */
 #define	NHORIZWS              	110	/* 0x6e not horizontal whitespace   (Perl 6) */
-#define	FOLDCHAR              	111	/* 0x6f codepoint with tricky case folding properties. */
-#define	OPTIMIZED             	112	/* 0x70 Placeholder for dump. */
-#define	PSEUDO                	113	/* 0x71 Pseudo opcode for internal use. */
+#define	OPTIMIZED             	111	/* 0x6f Placeholder for dump. */
+#define	PSEUDO                	112	/* 0x70 Pseudo opcode for internal use. */
 	/* ------------ States ------------- */
 #define	TRIE_next             	(REGNODE_MAX + 1)	/* state for TRIE */
 #define	TRIE_next_fail        	(REGNODE_MAX + 2)	/* state for TRIE */
@@ -282,7 +281,6 @@ EXTCONST U8 PL_regkind[] = {
 	NVERTWS,  	/* NVERTWS                */
 	HORIZWS,  	/* HORIZWS                */
 	NHORIZWS, 	/* NHORIZWS               */
-	FOLDCHAR, 	/* FOLDCHAR               */
 	NOTHING,  	/* OPTIMIZED              */
 	PSEUDO,   	/* PSEUDO                 */
 	/* ------------ States ------------- */
@@ -444,7 +442,6 @@ static const U8 regarglen[] = {
 	0,                                   	/* NVERTWS      */
 	0,                                   	/* HORIZWS      */
 	0,                                   	/* NHORIZWS     */
-	EXTRA_SIZE(struct regnode_1),        	/* FOLDCHAR     */
 	0,                                   	/* OPTIMIZED    */
 	0,                                   	/* PSEUDO       */
 };
@@ -563,7 +560,6 @@ static const char reg_off_by_arg[] = {
 	0,	/* NVERTWS      */
 	0,	/* HORIZWS      */
 	0,	/* NHORIZWS     */
-	0,	/* FOLDCHAR     */
 	0,	/* OPTIMIZED    */
 	0,	/* PSEUDO       */
 };
@@ -687,9 +683,8 @@ EXTCONST char * const PL_reg_name[] = {
 	"NVERTWS",               	/* 0x6c */
 	"HORIZWS",               	/* 0x6d */
 	"NHORIZWS",              	/* 0x6e */
-	"FOLDCHAR",              	/* 0x6f */
-	"OPTIMIZED",             	/* 0x70 */
-	"PSEUDO",                	/* 0x71 */
+	"OPTIMIZED",             	/* 0x6f */
+	"PSEUDO",                	/* 0x70 */
 	/* ------------ States ------------- */
 	"TRIE_next",             	/* REGNODE_MAX +0x01 */
 	"TRIE_next_fail",        	/* REGNODE_MAX +0x02 */