add rpp_invoke_xs() function

This function is just a neater version of:

    #ifdef PERL_RC_STACK
        Perl_xs_wrap(aTHX_ CvXSUB(cv), cv);
    #else
        (void)(*CvXSUB(cv))(aTHX_ cv);
    #endif

but shortly it will be extended to allow XS CVs to be flagged as
"RC-aware".

Author: iabyn

embed.fnc

@@ -2758,6 +2758,7 @@ APTdp	|char * |rninstr	|NN const char *big			\
 				|NN const char *lend
 p	|void	|rpeep		|NULLOK OP *o
 Adipx	|void	|rpp_extend	|SSize_t n
+Adipx	|void	|rpp_invoke_xs	|NN CV *cv
 Adipx	|bool	|rpp_is_lone	|NN SV *sv
 Cpx	|void	|rpp_obliterate_stack_to				\
 				|I32 ix

embed.h

@@ -538,6 +538,7 @@
 # define require_pv(a)                          Perl_require_pv(aTHX_ a)
 # define rninstr                                Perl_rninstr
 # define rpp_extend(a)                          Perl_rpp_extend(aTHX_ a)
+# define rpp_invoke_xs(a)                       Perl_rpp_invoke_xs(aTHX_ a)
 # define rpp_is_lone(a)                         Perl_rpp_is_lone(aTHX_ a)
 # define rpp_obliterate_stack_to(a)             Perl_rpp_obliterate_stack_to(aTHX_ a)
 # define rpp_pop_1_norc()                       Perl_rpp_pop_1_norc(aTHX)

inline.h

@@ -766,6 +766,31 @@ Perl_rpp_is_lone(pTHX_ SV *sv)
 }
 
 
+/*
+=for apidoc rpp_invoke_xs
+
+Call the XS function associated with C<cv>. Wraps the call if necessary to
+handle XS functions which are not aware of reference-counted stacks.
+
+=cut
+*/
+
+
+PERL_STATIC_INLINE void
+Perl_rpp_invoke_xs(pTHX_ CV *cv)
+{
+    PERL_ARGS_ASSERT_RPP_INVOKE_XS;
+
+#ifdef PERL_RC_STACK
+    Perl_xs_wrap(aTHX_ CvXSUB(cv), cv);
+#else
+    CvXSUB(cv)(aTHX_ cv);
+#endif
+}
+
+
+
+
 /* ----------------------------- regexp.h ----------------------------- */
 
 /* PVLVs need to act as a superset of all scalar types - they are basically

pod/perlguts.pod

@@ -4628,8 +4628,8 @@ the stack as:
 
     ... X+ Y+
 
-In places like pp_entersub(), a similar wrapping (via the function
-xs_wrap()) is done when calling XS subs.
+In places like pp_entersub(), a similar wrapping (via the functions
+rpp_invoke_xs() and then xs_wrap()) is done when calling XS subs.
 
 When C<nlists> is positive, a similar action takes place, except that the
 mark stack is examined (and adjusted) in order to determine the number of
@@ -4762,6 +4762,8 @@ in summary:
  rpp_is_lone(sv)         SvTEMP(sv) && SvREFCNT(sv) == 1
  rpp_stack_is_rc()       no equivalent
 
+ rpp_invoke_xs(cv)       CvXSUB(cv)(aTHX_ cv);
+
  (no replacement)        dATARGET   // just write the macro body in full
 
 Other new C and perl functions related to reference-counted stacks are:
@@ -4868,6 +4870,9 @@ with rpp_try_AMAGIC_1() and _2() inline functions, which now rely on the
 calling PP function to choose whether to return immediately rather than
 the return being hidden away in the macro.
 
+The rpp_invoke_xs() function calls the XS function associated with the CV,
+but may do so via a wrapper function to adjust the stack as necessary.
+
 In the spirit of hiding away less in macros, C<dATARGET> hasn't been given
 a replacement; where its effect is needed, it is now written out in full;
 see pp_add() for an example.

pp_ctl.c

@@ -2381,12 +2381,7 @@ PP(pp_dbstate)
 #endif
             SAVETMPS;
             PUSHMARK(PL_stack_sp);
-#ifdef PERL_RC_STACK
-            Perl_xs_wrap(aTHX_ CvXSUB(cv), cv);
-#else
-            CvXSUB(cv)(aTHX_ cv);
-#endif
-
+            rpp_invoke_xs(cv);
             FREETMPS;
             LEAVE;
             return NORMAL;
@@ -3361,11 +3356,7 @@ PP(pp_goto)
 
                 /* Push a mark for the start of arglist */
                 PUSHMARK(mark);
-#ifdef PERL_RC_STACK
-                Perl_xs_wrap(aTHX_ CvXSUB(cv), cv);
-#else
-                (void)(*CvXSUB(cv))(aTHX_ cv);
-#endif
+                rpp_invoke_xs(cv);
                 LEAVE;
                 goto finish;
             }

pp_hot.c

@@ -5822,11 +5822,7 @@ PP(pp_entersub)
         /* CvXSUB(cv) must not be NULL because newXS() refuses NULL xsub address */
         assert(CvXSUB(cv));
 
-#ifdef PERL_RC_STACK
-        Perl_xs_wrap(aTHX_ CvXSUB(cv), cv);
-#else
-        CvXSUB(cv)(aTHX_ cv);
-#endif
+        rpp_invoke_xs(cv);
 
 #if defined DEBUGGING && !defined DEBUGGING_RE_ONLY
         /* This duplicates the check done in runops_debug(), but provides more

pp_sort.c

@@ -1290,11 +1290,7 @@ S_sortcv_xsub(pTHX_ SV *const a, SV *const b)
     PUSHMARK(PL_stack_sp);
     rpp_xpush_2(a, b);
 
-#ifdef PERL_RC_STACK
-    Perl_xs_wrap(aTHX_ CvXSUB(cv), cv);
-#else
-    (void)(*CvXSUB(cv))(aTHX_ cv);
-#endif
+    rpp_invoke_xs(cv);
 
     /* entry zero of a stack is always PL_sv_undef, which
      * simplifies converting a '()' return into undef in scalar context */