Placeholder is not a unit-type

Placeholder types are containers for associated types, the code-generation
pass has a check for is_unit on return types for functions so we can inject
void_type_node. This was a false positive for placeholders, placeholders
must resolve to check what their concrete implementation type actually is
for this type of query.

1 files changed, 5 insertions, 1 deletions

diff --git a/gcc/rust/typecheck/rust-tyty.h b/gcc/rust/typecheck/rust-tyty.h
index 743874a..181be94 100644
--- a/gcc/rust/typecheck/rust-tyty.h
+++ b/gcc/rust/typecheck/rust-tyty.h
@@ -1709,7 +1709,11 @@ public:
 
   std::string get_name () const override final { return as_string (); }
 
-  bool is_unit () const override { return true; }
+  bool is_unit () const override
+  {
+    rust_assert (can_resolve ());
+    return resolve ()->is_unit ();
+  }
 
   std::string get_symbol () const { return symbol; }