[MERGE] ParseXS: build an AST for each XSUB

This series 156 commits changes ExtUtils::ParseXS so that, instead of
intermixing parsing and code-emitting for each XSUB, it now parses each
XSUB into an Abstract Syntax Tree, and then walks the tree to emit all
the C code for that XSUB.

This makes the code generally more understandable and maintainable.

For now it still just discards each tree after the XSUB is parsed; in
future work, the AST will be extended so that it holds the whole file
(including all the XSUBs) rather than just the current XSUB.

This branch contains six types of commit.

1) For terminal AST nodes for keywords such as FOO, the old

    ExtUtils::ParseXS::handle_FOO()

method is removed and a new ExtUtils::ParseXS::Node::FOO class is added
with parse() and as_code() methods which copy over the parsing and
code-emitting parts of the handle_FOO() method. For a few keywords like
INPUT which have values per line, both a Node::FOO and Node::FOO_line
class are created, with several FOO_line nodes being children of the FOO
node.

Note that doing the modifications for a single keyword often consists in
fact of several commits in sequence.

2) For higher-level nodes, a Node::foo class is created with parse() and
as_code() methods as before, but the contents of these methods are
typically populated by moving the relevant bits of code over from the
big ExtUtils::ParseXS::process_file() method.

3) Most of the state fields of the ExtUtils::ParseXS class (especially
all the xsub_foo ones) are removed, and similar fields added to the
various Node subclasses instead.

4) Fixups to ensure that all parse-time code is only in parse() methods
or associated helper functions, and similarly for as_code().

5) Various bug fixes related to state that should be per-CASE rather
than per-XSUB. Some of these bugs were pre-existing, some were
introduced during this branch.

6) General tidying-up, fixing code comments, adding POD etc.

Author: iabyn

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

@@ -3,7 +3,7 @@ use strict;
 use warnings;
 use Symbol;
 
-our $VERSION = '3.57';
+our $VERSION = '3.58';
 
 =head1 NAME
 

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

@@ -1,7 +1,7 @@
 package ExtUtils::ParseXS::CountLines;
 use strict;
 
-our $VERSION = '3.57';
+our $VERSION = '3.58';
 
 our $SECTION_END_MARKER;
 

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

@@ -2,7 +2,7 @@ package ExtUtils::ParseXS::Eval;
 use strict;
 use warnings;
 
-our $VERSION = '3.57';
+our $VERSION = '3.58';
 
 =head1 NAME
 
@@ -29,23 +29,20 @@ Warns the contents of C<$@> if any.
 Not all these variables are necessarily considered "public" wrt. use in
 typemaps, so beware. Variables set up from the ExtUtils::ParseXS object:
 
-  $Package $ALIAS $func_name $Full_func_name $pname
+  $Package $func_name $Full_func_name $pname
 
 Variables set up from C<$other_hashref>:
 
-  $var $type $ntype $subtype $arg
+  $var $type $ntype $subtype $arg $ALIAS
 
 =cut
 
 sub eval_output_typemap_code {
   my ($_pxs, $_code, $_other) = @_;
 
-  my ($Package, $ALIAS, $func_name, $Full_func_name, $pname)
-    = @{$_pxs}{qw(PACKAGE_name xsub_seen_ALIAS xsub_func_name
-                  xsub_func_full_C_name xsub_func_full_perl_name)};
-
-  my ($var, $type, $ntype, $subtype, $arg)
-    = @{$_other}{qw(var type ntype subtype arg)};
+  my ($Package) = @{$_pxs}{qw(PACKAGE_name)};
+  my ($var, $type, $ntype, $subtype, $arg, $ALIAS, $func_name, $Full_func_name, $pname)
+    = @{$_other}{qw(var type ntype subtype arg alias func_name full_C_name full_perl_name)};
 
   my $rv = eval $_code;
   warn $@ if $@;
@@ -64,23 +61,20 @@ Warns the contents of C<$@> if any.
 Not all these variables are necessarily considered "public" wrt. use in
 typemaps, so beware. Variables set up from the ExtUtils::ParseXS object:
 
-  $Package $ALIAS $func_name $Full_func_name $pname
+  $Package $func_name $Full_func_name $pname
 
 Variables set up from C<$other_hashref>:
 
-  $var $type $ntype $subtype $num $init $printed_name $arg $argoff
+  $var $type $ntype $subtype $num $init $printed_name $arg $argoff $ALIAS
 
 =cut
 
 sub eval_input_typemap_code {
   my ($_pxs, $_code, $_other) = @_;
 
-  my ($Package, $ALIAS, $func_name, $Full_func_name, $pname)
-    = @{$_pxs}{qw(PACKAGE_name xsub_seen_ALIAS xsub_func_name
-                  xsub_func_full_C_name xsub_func_full_perl_name)};
-
-  my ($var, $type, $num, $init, $printed_name, $arg, $ntype, $argoff, $subtype)
-    = @{$_other}{qw(var type num init printed_name arg ntype argoff subtype)};
+  my ($Package) = @{$_pxs}{qw(PACKAGE_name)};
+  my ($var, $type, $num, $init, $printed_name, $arg, $ntype, $argoff, $subtype, $ALIAS, $func_name, $Full_func_name, $pname)
+    = @{$_other}{qw(var type num init printed_name arg ntype argoff subtype alias func_name full_C_name full_perl_name)};
 
   my $rv = eval $_code;
   warn $@ if $@;