#define Perl_whichsig pPerl->Perl_whichsig
#undef whichsig
#define whichsig Perl_whichsig
-#if defined(USE_PURE_BISON)
+#ifdef USE_PURE_BISON
#else
#endif
#if defined(MYMALLOC)
and the pointer C<s> will be advanced to the end of the character.
If C<s> does not point to a well-formed UTF8 character, the behaviour
-is dependent on the value of C<checking>: if this is true, it is
-assumed that the caller will raise a warning, and this function will
-set C<retlen> to C<-1> and return. If C<checking> is not true, an optional UTF8
-warning is produced.
+is dependent on the value of C<flags>: if it contains UTF8_CHECK_ONLY,
+it is assumed that the caller will raise a warning, and this function
+will set C<retlen> to C<-1> and return. The C<flags> can also contain
+various flags to allow deviations from the strict UTF-8 encoding.
U8* s utf8_to_uv(STRLEN curlen, I32 *retlen, U32 flags)