add lex_re_reparsing boolean to yy_parser struct

When re-parsing a pattern for run-time (?{}) code blocks,
we end up with the EVAL_RE_REPARSING flag set in PL_in_eval.
Currently we clear this flag as soon as scan_str() returns, to ensure that
it's not set if we happen to parse further patterns (e.g. within the
(?{ ... }) code itself.

However, a soon-to-be-applied bugfix requires us to know the reparsing
state beyond this point. To solve this, we add a new boolean flag to the
parser struct, which is set from PL_in_eval in S_sublex_push() (with the
old value being saved). This allows us to have the flag around for the
entire pattern string parsing phase, without it affecting nested pattern
compilation.

4 files changed, 6 insertions, 8 deletions

diff --git a/parser.h b/parser.h
index 05735bfe76..e7b887ec3b 100644
--- a/parser.h
+++ b/parser.h
@@ -71,7 +71,7 @@ typedef struct yy_parser {
     char	multi_open;	/* delimiter of said string */
     char	multi_close;	/* delimiter of said string */
     bool	preambled;
-    /*** 8-bit hole ***/
+    bool        lex_re_reparsing; /* we're doing G_RE_REPARSING */
     I32		lex_allbrackets;/* (), [], {}, ?: bracket count */
     SUBLEXINFO	sublex_info;
     LEXSHARED	*lex_shared;
diff --git a/regcomp.c b/regcomp.c
index 0849a9716e..0853815a58 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -5652,8 +5652,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
     else if ((pm_flags & PMf_USE_RE_EVAL)
 		/* this second condition covers the non-regex literal case,
 		 * i.e.  $foo =~ '(?{})'. */
-		|| ( !(PL_in_eval & EVAL_RE_REPARSING) && IN_PERL_COMPILETIME
-		    && (PL_hints & HINT_RE_EVAL))
+		|| (IN_PERL_COMPILETIME && (PL_hints & HINT_RE_EVAL))
     )
 	runtime_code = S_has_runtime_code(aTHX_ pRExC_state, expr, pm_flags,
 			    exp, plen);
diff --git a/regexec.c b/regexec.c
index bb6c958f7a..45bd09ede3 100644
--- a/regexec.c
+++ b/regexec.c
@@ -4878,8 +4878,6 @@ S_regmatch(pTHX_ regmatch_info *reginfo, char *startpos, regnode *prog)
 		 */
 		Copy(&PL_reg_state, &saved_state, 1, struct re_save_state);
 
-                PL_in_eval &= ~EVAL_RE_REPARSING;
-
 		if (!caller_cv)
 		    caller_cv = find_runcv(NULL);
 
diff --git a/toke.c b/toke.c
index 4581bfdc1a..e97f3fa774 100644
--- a/toke.c
+++ b/toke.c
@@ -2525,6 +2525,7 @@ S_sublex_push(pTHX)
     SAVEGENERICPV(PL_lex_brackstack);
     SAVEGENERICPV(PL_lex_casestack);
     SAVEGENERICPV(PL_parser->lex_shared);
+    SAVEBOOL(PL_parser->lex_re_reparsing);
 
     /* The here-doc parser needs to be able to peek into outer lexing
        scopes to find the body of the here-doc.  So we put PL_linestr and
@@ -2568,6 +2569,9 @@ S_sublex_push(pTHX)
     else
 	PL_lex_inpat = NULL;
 
+    PL_parser->lex_re_reparsing = cBOOL(PL_in_eval & EVAL_RE_REPARSING);
+    PL_in_eval &= ~EVAL_RE_REPARSING;
+
     return '(';
 }
 
@@ -9517,9 +9521,6 @@ S_scan_pat(pTHX_ char *start, I32 type)
     s = scan_str(start,!!PL_madskills,FALSE, (PL_in_eval & EVAL_RE_REPARSING),
                        TRUE /* look for escaped bracketed metas */ );
 
-    /* this was only needed for the initial scan_str; set it to false
-     * so that any (?{}) code blocks etc are parsed normally */
-    PL_in_eval &= ~EVAL_RE_REPARSING;
     if (!s) {
 	const char * const delimiter = skipspace(start);
 	Perl_croak(aTHX_