Fix use of %_ and @_ when they've been declared in a signature (or au…

…to-included in the case of methods).

src/Perl6/Actions.pm

@@ -713,10 +713,14 @@ sub make_variable($/, $name) {
         $past := add_placeholder_parameter($<sigil>.Str, $<desigilname>.Str, :named($<twigil>[0] eq ':'));
     }
     elsif ~$/ eq '@_' {
-        $past := add_placeholder_parameter('@', '_', :slurpy_pos(1));
+        unless get_nearest_signature().declares_symbol('@_') {
+            $past := add_placeholder_parameter('@', '_', :slurpy_pos(1));
+        }
     }
     elsif ~$/ eq '%_' {
-        $past := add_placeholder_parameter('%', '_', :slurpy_named(1));
+        unless get_nearest_signature().declares_symbol('%_') {
+            $past := add_placeholder_parameter('%', '_', :slurpy_named(1));
+        }
     }
     else {
         my $attr_alias := is_attr_alias($past.name);
@@ -1429,6 +1433,7 @@ method signature($/) {
         $signature.add_parameter($param);
         $cur_param := $cur_param + 1;
     }
+    @BLOCK[0]<signature> := $signature;
     make $signature;
 }
 
@@ -2560,6 +2565,17 @@ sub add_placeholder_parameter($sigil, $ident, :$named, :$slurpy_pos, :$slurpy_na
     return PAST::Var.new( :name(~$sigil ~ ~$ident), :scope('lexical') );
 }
 
+# Looks through the blocks for the first one with a signature and returns
+# that signature.
+sub get_nearest_signature() {
+    for @BLOCK {
+        if pir::defined__IP($_<signature>) {
+            return $_<signature>;
+        }
+    }
+    Perl6::Compiler::Signature.new()
+}
+
 # Wraps a sub up in a block type.
 sub create_code_object($block, $type, $multiness, $lazy_init) {
     my @name := Perl6::Grammar::parse_name($type);

src/Perl6/Compiler/Signature.pm

@@ -365,6 +365,17 @@ method entries() {
     $!entries
 }
 
+
+# Tests if the signature declares the given symbol.
+method declares_symbol($name) {
+    for self.entries {
+        if $_.var_name eq $name {
+            return 1;
+        }
+    }
+    return 0;
+}
+
 # Local Variables:
 #   mode: cperl
 #   cperl-indent-level: 4