+
+/* The character set for the regex is stored in a field of more than one bit
+ * using an enum, for reasons of compactness and to ensure that the options are
+ * mutually exclusive */
+/* Make sure to update ext/re/re.pm and regcomp.sym (as these are used as
+ * offsets for various node types, like POSIXD vs POSIXL, etc) when changing
+ * this! */
+typedef enum {
+ REGEX_DEPENDS_CHARSET = 0,
+ REGEX_LOCALE_CHARSET,
+ REGEX_UNICODE_CHARSET,
+ REGEX_ASCII_RESTRICTED_CHARSET,
+ REGEX_ASCII_MORE_RESTRICTED_CHARSET
+} regex_charset;
+
+#define _RXf_PMf_CHARSET_SHIFT ((RXf_PMf_STD_PMMOD_SHIFT)+5)
+#define RXf_PMf_CHARSET (7 << (_RXf_PMf_CHARSET_SHIFT)) /* 3 bits */
+
+/* Manually decorate these functions here with gcc-style attributes just to
+ * avoid making the regex_charset typedef global, which it would need to be for
+ * proto.h to understand it */
+PERL_STATIC_INLINE void
+set_regex_charset(U32 * const flags, const regex_charset cs)
+ __attribute__nonnull__(1);
+
+PERL_STATIC_INLINE void
+set_regex_charset(U32 * const flags, const regex_charset cs)
+{
+ /* Sets the character set portion of 'flags' to 'cs', which is a member of
+ * the above enum */
+
+ *flags &= ~RXf_PMf_CHARSET;
+ *flags |= (cs << _RXf_PMf_CHARSET_SHIFT);
+}
+
+PERL_STATIC_INLINE regex_charset
+get_regex_charset(const U32 flags)
+ __attribute__warn_unused_result__;
+
+PERL_STATIC_INLINE regex_charset
+get_regex_charset(const U32 flags)
+{
+ /* Returns the enum corresponding to the character set in 'flags' */
+
+ return (regex_charset) ((flags & RXf_PMf_CHARSET) >> _RXf_PMf_CHARSET_SHIFT);
+}
+
+#define _RXf_PMf_SHIFT_COMPILETIME (RXf_PMf_STD_PMMOD_SHIFT+8)
+
+/*
+ Set in Perl_pmruntime if op_flags & OPf_SPECIAL, i.e. split. Will
+ be used by regex engines to check whether they should set
+ RXf_SKIPWHITE
+*/
+#define RXf_PMf_SPLIT (1<<(RXf_PMf_STD_PMMOD_SHIFT+8))