regcomp.c: Don't iterate while changing an inversion list

This adds functions to prevent accidental (or deliberate) iteration over
an inversion list while it is being modified.  This is to catch
development errors, and in production builds, the asserts() are likely
no-ops

1 files changed, 11 insertions, 0 deletions

diff --git a/proto.h b/proto.h
index 1151167d64..d9435b59ca 100644
--- a/proto.h
+++ b/proto.h
@@ -6509,6 +6509,17 @@ PERL_STATIC_INLINE UV	S_invlist_highest(pTHX_ SV* const invlist)
 #define PERL_ARGS_ASSERT_INVLIST_HIGHEST	\
 	assert(invlist)
 
+PERL_STATIC_INLINE bool	S_invlist_is_iterating(pTHX_ SV* const invlist)
+			__attribute__warn_unused_result__
+			__attribute__nonnull__(pTHX_1);
+#define PERL_ARGS_ASSERT_INVLIST_IS_ITERATING	\
+	assert(invlist)
+
+STATIC void	S_invlist_iterfinish(pTHX_ SV* invlist)
+			__attribute__nonnull__(pTHX_1);
+#define PERL_ARGS_ASSERT_INVLIST_ITERFINISH	\
+	assert(invlist)
+
 PERL_STATIC_INLINE void	S_invlist_iterinit(pTHX_ SV* invlist)
 			__attribute__nonnull__(pTHX_1);
 #define PERL_ARGS_ASSERT_INVLIST_ITERINIT	\