Change unit-type to be an empty struct so that we do not disregard the

initilizer of variables

Author: philberty

gcc/rust/backend/rust-compile-stmt.h

@@ -81,6 +81,7 @@ class CompileStmt : public HIRCompileBase, public HIR::HIRStmtVisitor
     bool ok = ctx->get_tyctx ()->lookup_type (
       stmt.get_init_expr ()->get_mappings ().get_hirid (), &actual);
     rust_assert (ok);
+    tree stmt_type = TyTyResolveCompile::compile (ctx, ty);
 
     Location lvalue_locus = stmt.get_pattern ()->get_locus ();
     Location rvalue_locus = stmt.get_init_expr ()->get_locus ();
@@ -90,8 +91,14 @@ class CompileStmt : public HIRCompileBase, public HIR::HIRStmtVisitor
     auto fnctx = ctx->peek_fn ();
     if (ty->is_unit ())
       {
-	// FIXME this feels wrong
 	ctx->add_statement (init);
+
+	auto unit_type_init_expr
+	  = ctx->get_backend ()->constructor_expression (stmt_type, false, {},
+							 -1, rvalue_locus);
+	auto s = ctx->get_backend ()->init_statement (fnctx.fndecl, var,
+						      unit_type_init_expr);
+	ctx->add_statement (s);
       }
     else
       {

gcc/rust/backend/rust-compile-tyty.h

@@ -54,10 +54,10 @@ class TyTyCompile : public TyTy::TyVisitor
 
   void visit (TyTy::TupleType &type) override
   {
-    if (type.num_fields () == 0)
-      translated = backend->unit_type ();
-    else
-      gcc_unreachable ();
+    // this interface is only for unit-type the -type interface takes into
+    // account the context
+    rust_assert (type.num_fields () == 0);
+    translated = backend->unit_type ();
   }
 
   void visit (TyTy::ArrayType &) override { gcc_unreachable (); }

gcc/rust/rust-gcc.cc

@@ -122,7 +122,7 @@ class Gcc_backend : public Backend
     static tree unit_type;
     if (unit_type == nullptr)
       {
-	auto unit_type_node = integer_type (true, 0);
+	auto unit_type_node = struct_type ({});
 	unit_type = named_type ("()", unit_type_node,
 				::Linemap::predeclared_location ());
       }