Add Generic Impl block support

This extends the support from #237 to extend this to MethodCallExpr, this
now follows a similar path to normal CallExprs and ensures the used
arguments in substitution are preserved during unification of types. Part
of method resolution is fixed here by taking advantage if is_equal instead
of unify calls which could result in bad errors which are just part of the
probe process to lookup possible candidates for method resolution.

Fixes #306

1 files changed, 15 insertions, 0 deletions

diff --git a/gcc/rust/backend/rust-compile-implitem.h b/gcc/rust/backend/rust-compile-implitem.h
index 15aba9b..cee3a3b 100644
--- a/gcc/rust/backend/rust-compile-implitem.h
+++ b/gcc/rust/backend/rust-compile-implitem.h
@@ -272,6 +272,21 @@ public:
       }
 
     TyTy::FnType *fntype = static_cast<TyTy::FnType *> (fntype_tyty);
+    if (fntype->has_subsititions_defined ())
+      {
+	// we cant do anything for this only when it is used
+	if (concrete == nullptr)
+	  return;
+	else
+	  {
+	    rust_assert (concrete->get_kind () == TyTy::TypeKind::FNDEF);
+	    fntype = static_cast<TyTy::FnType *> (concrete);
+
+	    // override the Hir Lookups for the substituions in this context
+	    fntype->override_context ();
+	  }
+      }
+
     // convert to the actual function type
     ::Btype *compiled_fn_type = TyTyResolveCompile::compile (ctx, fntype);