fix error reporting for anon vars [RT #123584]

`$; my $b;` now gives correctly: Useless use of variable $ in sink context (line 1)
rakudo · Feb 7, 2015 · d728669 · d728669
1 parent 1b24050
commit d728669
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Showing 2 changed files with 20 additions and 6 deletions.
diff --git a/src/Perl6/Actions.nqp b/src/Perl6/Actions.nqp
@@ -2263,6 +2263,7 @@ class Perl6::Actions is HLL::Actions does STDActions {
         }
         elsif $*SCOPE eq 'my' || $*SCOPE eq 'our' || $*SCOPE eq 'state' {
             # Some things can't be done to our vars.
+            my $varname;
             if $*SCOPE eq 'our' {
                 if $*OFTYPE {
                     $/.CURSOR.panic("Cannot put a type constraint on an 'our'-scoped variable");
@@ -2278,14 +2279,15 @@ class Perl6::Actions is HLL::Actions does STDActions {
                 if $twigil {
                     $/.CURSOR.panic("Cannot have an anonymous variable with a twigil");
                 }
-                $name := QAST::Node.unique($sigil ~ 'ANON_VAR_');
+                $name    := QAST::Node.unique($sigil ~ 'ANON_VAR_');
+                $varname := $sigil;
             }
 
             # Create a container descriptor. Default to rw and set a
             # type if we have one; a trait may twiddle with that later.
             my %cont_info  := $*W.container_type_info($/, $sigil, $*OFTYPE ?? [$*OFTYPE.ast] !! [], $shape);
             my $descriptor := $*W.create_container_descriptor(
-              %cont_info<value_type>, 1, $name, %cont_info<default_value>);
+              %cont_info<value_type>, 1, $varname || $name, %cont_info<default_value>);
 
             # Install the container.
             my $cont := $*W.install_lexical_container($BLOCK, $name, %cont_info, $descriptor,

diff --git a/src/Perl6/Optimizer.nqp b/src/Perl6/Optimizer.nqp
@@ -173,6 +173,17 @@ my class Symbols {
         nqp::die("Optimizer: No lexical $name found");
     }
 
+    method find_lexical_symbol($name) {
+        my int $i := +@!block_stack;
+        while $i > 0 {
+            $i := $i - 1;
+            my $block := @!block_stack[$i];
+            my %sym := $block.symbol($name);
+            return %sym if +%sym;
+        }
+        nqp::die("Optimizer: No lexical $name found");
+    }
+
     # Checks if a given lexical is declared, though it needn't have a compile
     # time known value.
     method is_lexical_declared($name) {
@@ -1508,14 +1519,15 @@ class Perl6::Optimizer {
         if $!void_context && !$!in_declaration && $var.name && !$var.ann('sink_ok') {
             # stuff like Nil is also stored in a QAST::Var, but
             # we certainly don't want to warn about that one.
-            my str $sigil := nqp::substr($var.name, 0, 1);
-            my str $name  := nqp::substr($var.name, 1);
+            my str $name  := try $!symbols.find_lexical_symbol($var.name)<descriptor>.name;
+            $name         := $var.name unless $name;
+            my str $sigil := nqp::substr($name, 0, 1);
             if $sigil eq '$' || $sigil eq '@' || $sigil eq '%' {
                 $!problems.add_worry(
                   $var,
-                  $name eq ''
+                  $name eq $sigil
                     ?? "Useless use of unnamed $sigil variable in sink context"
-                    !! "Useless use of variable $sigil$name in sink context"
+                    !! "Useless use of variable $name in sink context"
                 );
                 return $NULL;
             }