Introduce ada_wrapped_operation

This adds class ada_wrapped_operation, which is used to wrap some
generic operations with a bit of Ada-specific handling.  This
corresponds to the old "default" case in ada_evaluate_subexp.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* ada-lang.c (ada_wrapped_operation::evaluate): New method.
	* ada-exp.h: New file.

1 files changed, 47 insertions, 0 deletions

diff --git a/gdb/ada-exp.h b/gdb/ada-exp.h
new file mode 100644
index 00000000000..3f780dc9ff4
--- /dev/null
+++ b/gdb/ada-exp.h
@@ -0,0 +1,47 @@
+/* Definitions for Ada expressions
+
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef ADA_EXP_H
+#define ADA_EXP_H
+
+#include "expop.h"
+
+namespace expr
+{
+
+/* In Ada, some generic operations must be wrapped with a handler that
+   handles some Ada-specific type conversions.  */
+class ada_wrapped_operation
+  : public tuple_holding_operation<operation_up>
+{
+public:
+
+  using tuple_holding_operation::tuple_holding_operation;
+
+  value *evaluate (struct type *expect_type,
+		   struct expression *exp,
+		   enum noside noside) override;
+
+  enum exp_opcode opcode () const override
+  { return std::get<0> (m_storage)->opcode (); }
+};
+
+} /* namespace expr */
+
+#endif /* ADA_EXP_H */