ParseXS: refactor: rm xsub_interface_macro fields

Remove the following fields from the ExtUtils::ParseXS class:

    xsub_interface_macro
    xsub_interface_macro_set

and replace them with these new fields in the
ExtUtils::ParseXS::Node::xsub class:

    interface_macro
    interface_macro_set

There is also a slight change in the way these two fields are used.
Formerly they were initialised to the default values "XSINTERFACE_FUNC"
and "XSINTERFACE_FUNC_SET", then potentially changed by the
INTERFACE_MACRO keyword, then the current values were used to emit the
interface function pointer getting and setting code.

Now, the values are initially undef, and the emitting code checks for
defined-ness and if so uses the default value. This means that the logic
for using default or overridden value is local to where that value is
used rather than being hidden away elsewhere.No change in functionality
though.

Author: iabyn

dist/ExtUtils-ParseXS/lib/ExtUtils/ParseXS.pm

@@ -235,10 +235,6 @@ BEGIN {
 
   'cur_xbody',                 # The Node::xbody currently being parsed
 
-  'xsub_interface_macro',      # Str: current interface extraction macro.
-
-  'xsub_interface_macro_set',  # Str: current interface setting macro.
-  
   'xsub_prototype',            # Str: is set to either the global PROTOTYPES
                                #  values (0 or 1), or to what's been
                                #  overridden for this XSUB with PROTOTYPE
@@ -582,8 +578,6 @@ EOM
 
     # Initialize some per-XSUB instance variables:
 
-    $self->{xsub_interface_macro}      = 'XSINTERFACE_FUNC';
-    $self->{xsub_interface_macro_set}  = 'XSINTERFACE_FUNC_SET';
     $self->{xsub_prototype}            = $self->{PROTOTYPES_value};
     $self->{xsub_SCOPE_enabled}        = 0;
     $self->{xsub_map_overload_name_to_seen} = {};

dist/ExtUtils-ParseXS/lib/ExtUtils/ParseXS/Node.pm

@@ -244,6 +244,11 @@ BEGIN { $build_subclass->('', # parent
     'attributes',              # Array of strings: all ATTRIBUTE keywords
                                # (possibly multiple space-separated
                                # keywords per string).
+
+    # INTERFACE_MACRO state
+
+    'interface_macro',      # Str: value of interface extraction macro.
+    'interface_macro_set',  # Str: value of interface setting macro.
 )};
 
 
@@ -569,9 +574,12 @@ EOF
         {
             my $value = $pxs->{cur_xsub}{map_interface_name_short_to_original}{$yname};
             $yname = "$pxs->{PACKAGE_name}\::$yname" unless $yname =~ /::/;
+
+            my $macro = $pxs->{cur_xsub}{interface_macro_set};
+            $macro = 'XSINTERFACE_FUNC_SET' unless defined $macro;
             push(@code, ExtUtils::ParseXS::Q(<<"EOF"));
                 |        cv = $newXS(\"$yname\", XS_$cname$file_arg$proto_arg);
-                |        $pxs->{xsub_interface_macro_set}(cv,$value);
+                |        $macro(cv,$value);
 EOF
             $pxs->{need_boot_cv} = 1;
         }
@@ -3180,8 +3188,11 @@ sub as_code {
     my ExtUtils::ParseXS::Node::xsub  $xsub  = shift;
     my ExtUtils::ParseXS::Node::xbody $xbody = shift;
 
+    my $macro = $xsub->{interface_macro};
+    $macro = 'XSINTERFACE_FUNC' unless defined $macro;
+
     print <<"EOF";
-    XSFUNCTION = $pxs->{xsub_interface_macro}($xsub->{decl}{return_type}{type},cv,XSANY.any_dptr);
+    XSFUNCTION = $macro($xsub->{decl}{return_type}{type},cv,XSANY.any_dptr);
 EOF
 }
 
@@ -3218,8 +3229,8 @@ sub parse {
         ($m1, $m2) = ($s, 'UNKNOWN_CVT');
     }
 
-    $self->{get_macro} = $pxs->{xsub_interface_macro}     = $m1;
-    $self->{set_macro} = $pxs->{xsub_interface_macro_set} = $m2;
+    $self->{get_macro} = $pxs->{cur_xsub}{interface_macro}     = $m1;
+    $self->{set_macro} = $pxs->{cur_xsub}{interface_macro_set} = $m2;
 
     1;
 }