To handle this situation, the PPCODE directive is used and the stack is
extended using the macro:
- EXTEND(sp, num);
+ EXTEND(SP, num);
-where C<sp> is the stack pointer, and C<num> is the number of elements the
-stack should be extended by.
+where C<SP> is the macro that represents the local copy of the stack pointer,
+and C<num> is the number of elements the stack should be extended by.
Now that there is room on the stack, values can be pushed on it using the
macros to push IVs, doubles, strings, and SV pointers respectively:
functions:
dSP
+ SP
PUSHMARK()
PUTBACK
SPAGAIN
=item dSP
-Declares a stack pointer variable, C<sp>, for the XSUB. See C<SP>.
+Declares a local copy of perl's stack pointer for the XSUB, available via
+the C<SP> macro. See C<SP>.
=item dXSARGS