XSUB. This is always the proper type for the C++ object. See C<CLASS> and
L<perlxs/"Using XS With C++">.
+=for apidoc Amn|I32|ax
+Variable which is setup by C<xsubpp> to indicate the stack base offset,
+used by the C<ST>, C<XSprePUSH> and C<XSRETURN> macros. The C<dMARK> macro
+must be called prior to setup the C<MARK> variable.
+
=for apidoc Amn|I32|items
Variable which is setup by C<xsubpp> to indicate the number of
items on the stack. See L<perlxs/"Variable-length Parameter Lists">.
Macro to declare an XSUB and its C parameter list. This is handled by
C<xsubpp>.
+=for apidoc Ams||dAX
+Sets up the C<ax> variable.
+This is usually handled automatically by C<xsubpp> by calling C<dXSARGS>.
+
+=for apidoc Ams||dITEMS
+Sets up the C<items> variable.
+This is usually handled automatically by C<xsubpp> by calling C<dXSARGS>.
+
=for apidoc Ams||dXSARGS
-Sets up stack and mark pointers for an XSUB, calling dSP and dMARK. This
-is usually handled automatically by C<xsubpp>. Declares the C<items>
-variable to indicate the number of items on the stack.
+Sets up stack and mark pointers for an XSUB, calling dSP and dMARK.
+Sets up the C<ax> and C<items> variables by calling C<dAX> and C<dITEMS>.
+This is usually handled automatically by C<xsubpp>.
=for apidoc Ams||dXSI32
Sets up the C<ix> variable for an XSUB which has aliases. This is usually
/* gcc -Wall: if an xsub has no arguments and PPCODE is used
* and none of ST, XSRETURN or XSprePUSH macros are used
* then `ax' (setup by dXSARGS) is unused. */
+#define dAX I32 ax __attribute__((unused)) = MARK - PL_stack_base + 1
+
+#define dITEMS I32 items = SP - MARK
+
#define dXSARGS \
dSP; dMARK; \
- I32 ax __attribute__((unused)) = mark - PL_stack_base + 1; \
- I32 items = sp - mark
+ dAX; dITEMS
#define dXSTARG SV * targ = ((PL_op->op_private & OPpENTERSUB_HASTARG) \
? PAD_SV(PL_op->op_targ) : sv_newmortal())