1 files changed, 272 insertions, 8 deletions

diff --git a/gcc/rust/backend/rust-compile-expr.cc b/gcc/rust/backend/rust-compile-expr.cc
index d66aa5d..738c7b1 100644
--- a/gcc/rust/backend/rust-compile-expr.cc
+++ b/gcc/rust/backend/rust-compile-expr.cc
@@ -1589,9 +1589,7 @@ CompileExpr::visit (HIR::CallExpr &expr)
     }
 
   // must be a tuple constructor
-  bool is_fn = tyty->get_kind () == TyTy::TypeKind::FNDEF
-	       || tyty->get_kind () == TyTy::TypeKind::FNPTR;
-  bool is_adt_ctor = !is_fn;
+  bool is_adt_ctor = tyty->get_kind () == TyTy::TypeKind::ADT;
   if (is_adt_ctor)
     {
       rust_assert (tyty->get_kind () == TyTy::TypeKind::ADT);
@@ -1692,6 +1690,57 @@ CompileExpr::visit (HIR::CallExpr &expr)
     return true;
   };
 
+  auto fn_address = CompileExpr::Compile (expr.get_fnexpr (), ctx);
+
+  // is this a closure call?
+  if (RS_CLOSURE_TYPE_P (TREE_TYPE (fn_address)))
+    {
+      rust_assert (tyty->get_kind () == TyTy::TypeKind::CLOSURE);
+      TyTy::ClosureType *closure = static_cast<TyTy::ClosureType *> (tyty);
+
+      std::vector<tree> tuple_arg_vals;
+      for (auto &argument : expr.get_arguments ())
+	{
+	  auto rvalue = CompileExpr::Compile (argument.get (), ctx);
+	  tuple_arg_vals.push_back (rvalue);
+	}
+
+      tree tuple_args_tyty
+	= TyTyResolveCompile::compile (ctx, &closure->get_parameters ());
+      tree tuple_args
+	= ctx->get_backend ()->constructor_expression (tuple_args_tyty, false,
+						       tuple_arg_vals, -1,
+						       expr.get_locus ());
+
+      // need to apply any autoderef's to the self argument
+      HirId autoderef_mappings_id = expr.get_mappings ().get_hirid ();
+      std::vector<Resolver::Adjustment> *adjustments = nullptr;
+      bool ok
+	= ctx->get_tyctx ()->lookup_autoderef_mappings (autoderef_mappings_id,
+							&adjustments);
+      rust_assert (ok);
+
+      // apply adjustments for the fn call
+      tree self
+	= resolve_adjustements (*adjustments, fn_address, expr.get_locus ());
+
+      // args are always self, and the tuple of the args we are passing where
+      // self is the path of the call-expr in this case the fn_address
+      std::vector<tree> args;
+      args.push_back (self);
+      args.push_back (tuple_args);
+
+      // get the fn call address
+      tree closure_call_site = ctx->lookup_closure_decl (closure);
+      tree closure_call_address
+	= address_expression (closure_call_site, expr.get_locus ());
+      translated
+	= ctx->get_backend ()->call_expression (closure_call_address, args,
+						nullptr /* static chain ?*/,
+						expr.get_locus ());
+      return;
+    }
+
   bool is_varadic = false;
   if (tyty->get_kind () == TyTy::TypeKind::FNDEF)
     {
@@ -1699,13 +1748,13 @@ CompileExpr::visit (HIR::CallExpr &expr)
       is_varadic = fn->is_varadic ();
     }
 
-  size_t required_num_args;
+  size_t required_num_args = expr.get_arguments ().size ();
   if (tyty->get_kind () == TyTy::TypeKind::FNDEF)
     {
       const TyTy::FnType *fn = static_cast<const TyTy::FnType *> (tyty);
       required_num_args = fn->num_params ();
     }
-  else
+  else if (tyty->get_kind () == TyTy::TypeKind::FNPTR)
     {
       const TyTy::FnPtr *fn = static_cast<const TyTy::FnPtr *> (tyty);
       required_num_args = fn->num_params ();
@@ -1746,8 +1795,7 @@ CompileExpr::visit (HIR::CallExpr &expr)
       args.push_back (rvalue);
     }
 
-  // must be a call to a function
-  auto fn_address = CompileExpr::Compile (expr.get_fnexpr (), ctx);
+  // must be a regular call to a function
   translated = ctx->get_backend ()->call_expression (fn_address, args, nullptr,
 						     expr.get_locus ());
 }
@@ -2801,7 +2849,223 @@ CompileExpr::visit (HIR::ArrayIndexExpr &expr)
 void
 CompileExpr::visit (HIR::ClosureExpr &expr)
 {
-  gcc_unreachable ();
+  TyTy::BaseType *closure_expr_ty = nullptr;
+  if (!ctx->get_tyctx ()->lookup_type (expr.get_mappings ().get_hirid (),
+				       &closure_expr_ty))
+    {
+      rust_fatal_error (expr.get_locus (),
+			"did not resolve type for this ClosureExpr");
+      return;
+    }
+  rust_assert (closure_expr_ty->get_kind () == TyTy::TypeKind::CLOSURE);
+  TyTy::ClosureType *closure_tyty
+    = static_cast<TyTy::ClosureType *> (closure_expr_ty);
+  tree compiled_closure_tyty = TyTyResolveCompile::compile (ctx, closure_tyty);
+
+  // generate closure function
+  generate_closure_function (expr, *closure_tyty, compiled_closure_tyty);
+
+  // lets ignore state capture for now we need to instantiate the struct anyway
+  // then generate the function
+
+  std::vector<tree> vals;
+  // TODO
+  // setup argument captures based on the mode?
+
+  translated
+    = ctx->get_backend ()->constructor_expression (compiled_closure_tyty, false,
+						   vals, -1, expr.get_locus ());
+}
+
+tree
+CompileExpr::generate_closure_function (HIR::ClosureExpr &expr,
+					TyTy::ClosureType &closure_tyty,
+					tree compiled_closure_tyty)
+{
+  TyTy::FnType *fn_tyty = nullptr;
+  tree compiled_fn_type
+    = generate_closure_fntype (expr, closure_tyty, compiled_closure_tyty,
+			       &fn_tyty);
+  if (compiled_fn_type == error_mark_node)
+    return error_mark_node;
+
+  const Resolver::CanonicalPath &parent_canonical_path
+    = closure_tyty.get_ident ().path;
+  Resolver::CanonicalPath path = parent_canonical_path.append (
+    Resolver::CanonicalPath::new_seg (UNKNOWN_NODEID, "{{closure}}"));
+
+  std::string ir_symbol_name = path.get ();
+  std::string asm_name = ctx->mangle_item (&closure_tyty, path);
+
+  unsigned int flags = 0;
+  tree fndecl
+    = ctx->get_backend ()->function (compiled_fn_type, ir_symbol_name, asm_name,
+				     flags, expr.get_locus ());
+
+  // insert into the context
+  ctx->insert_function_decl (fn_tyty, fndecl);
+  ctx->insert_closure_decl (&closure_tyty, fndecl);
+
+  // setup the parameters
+  std::vector<Bvariable *> param_vars;
+
+  // closure self
+  Bvariable *self_param
+    = ctx->get_backend ()->parameter_variable (fndecl, "$closure",
+					       compiled_closure_tyty,
+					       expr.get_locus ());
+  DECL_ARTIFICIAL (self_param->get_decl ()) = 1;
+  param_vars.push_back (self_param);
+
+  // setup the implicit argument captures
+  // TODO
+
+  // args tuple
+  tree args_type
+    = TyTyResolveCompile::compile (ctx, &closure_tyty.get_parameters ());
+  Bvariable *args_param
+    = ctx->get_backend ()->parameter_variable (fndecl, "args", args_type,
+					       expr.get_locus ());
+  param_vars.push_back (args_param);
+
+  // setup the implicit mappings for the arguments. Since argument passing to
+  // closure functions is done via passing a tuple but the closure body expects
+  // just normal arguments this means we need to destructure them similar to
+  // what we do in MatchExpr's. This means when we have a closure-param of a we
+  // actually setup the destructure to take from the args tuple
+
+  tree args_param_expr = args_param->get_tree (expr.get_locus ());
+  size_t i = 0;
+  for (auto &closure_param : expr.get_params ())
+    {
+      tree compiled_param_var = ctx->get_backend ()->struct_field_expression (
+	args_param_expr, i, closure_param.get_locus ());
+
+      const HIR::Pattern &param_pattern = *closure_param.get_pattern ();
+      ctx->insert_pattern_binding (
+	param_pattern.get_pattern_mappings ().get_hirid (), compiled_param_var);
+      i++;
+    }
+
+  if (!ctx->get_backend ()->function_set_parameters (fndecl, param_vars))
+    return error_mark_node;
+
+  // lookup locals
+  HIR::Expr *function_body = expr.get_expr ().get ();
+  auto body_mappings = function_body->get_mappings ();
+  Resolver::Rib *rib = nullptr;
+  bool ok
+    = ctx->get_resolver ()->find_name_rib (body_mappings.get_nodeid (), &rib);
+  rust_assert (ok);
+
+  std::vector<Bvariable *> locals
+    = compile_locals_for_block (ctx, *rib, fndecl);
+
+  tree enclosing_scope = NULL_TREE;
+  Location start_location = function_body->get_locus ();
+  Location end_location = function_body->get_locus ();
+  bool is_block_expr
+    = function_body->get_expression_type () == HIR::Expr::ExprType::Block;
+  if (is_block_expr)
+    {
+      HIR::BlockExpr *body = static_cast<HIR::BlockExpr *> (function_body);
+      start_location = body->get_locus ();
+      end_location = body->get_end_locus ();
+    }
+
+  tree code_block = ctx->get_backend ()->block (fndecl, enclosing_scope, locals,
+						start_location, end_location);
+  ctx->push_block (code_block);
+
+  TyTy::BaseType *tyret = &closure_tyty.get_result_type ();
+  bool function_has_return = !closure_tyty.get_result_type ().is_unit ();
+  Bvariable *return_address = nullptr;
+  if (function_has_return)
+    {
+      tree return_type = TyTyResolveCompile::compile (ctx, tyret);
+
+      bool address_is_taken = false;
+      tree ret_var_stmt = NULL_TREE;
+
+      return_address = ctx->get_backend ()->temporary_variable (
+	fndecl, code_block, return_type, NULL, address_is_taken,
+	expr.get_locus (), &ret_var_stmt);
+
+      ctx->add_statement (ret_var_stmt);
+    }
+
+  ctx->push_fn (fndecl, return_address);
+
+  if (is_block_expr)
+    {
+      HIR::BlockExpr *body = static_cast<HIR::BlockExpr *> (function_body);
+      compile_function_body (ctx, fndecl, *body, true);
+    }
+  else
+    {
+      tree value = CompileExpr::Compile (function_body, ctx);
+      tree return_expr
+	= ctx->get_backend ()->return_statement (fndecl, {value},
+						 function_body->get_locus ());
+      ctx->add_statement (return_expr);
+    }
+
+  tree bind_tree = ctx->pop_block ();
+
+  gcc_assert (TREE_CODE (bind_tree) == BIND_EXPR);
+  DECL_SAVED_TREE (fndecl) = bind_tree;
+
+  ctx->pop_fn ();
+  ctx->push_function (fndecl);
+
+  return fndecl;
+}
+
+tree
+CompileExpr::generate_closure_fntype (HIR::ClosureExpr &expr,
+				      const TyTy::ClosureType &closure_tyty,
+				      tree compiled_closure_tyty,
+				      TyTy::FnType **fn_tyty)
+{
+  // grab the specified_bound
+  rust_assert (closure_tyty.num_specified_bounds () == 1);
+  const TyTy::TypeBoundPredicate &predicate
+    = *closure_tyty.get_specified_bounds ().begin ();
+
+  // ensure the fn_once_output associated type is set
+  closure_tyty.setup_fn_once_output ();
+
+  // the function signature is based on the trait bound that the closure
+  // implements which is determined at the type resolution time
+  //
+  // https://github.com/rust-lang/rust/blob/7807a694c2f079fd3f395821bcc357eee8650071/library/core/src/ops/function.rs#L54-L71
+
+  TyTy::TypeBoundPredicateItem item = TyTy::TypeBoundPredicateItem::error ();
+  if (predicate.get_name ().compare ("FnOnce") == 0)
+    {
+      item = predicate.lookup_associated_item ("call_once");
+    }
+  else if (predicate.get_name ().compare ("FnMut") == 0)
+    {
+      item = predicate.lookup_associated_item ("call_mut");
+    }
+  else if (predicate.get_name ().compare ("Fn") == 0)
+    {
+      item = predicate.lookup_associated_item ("call");
+    }
+  else
+    {
+      // FIXME error message?
+      gcc_unreachable ();
+      return error_mark_node;
+    }
+
+  rust_assert (!item.is_error ());
+
+  TyTy::BaseType *item_tyty = item.get_tyty_for_receiver (&closure_tyty);
+  rust_assert (item_tyty->get_kind () == TyTy::TypeKind::FNDEF);
+  *fn_tyty = static_cast<TyTy::FnType *> (item_tyty);
+  return TyTyResolveCompile::compile (ctx, item_tyty);
 }
 
 } // namespace Compile