From 165a813a3abaa1f5993d754765bff2cfa9755995 Mon Sep 17 00:00:00 2001
From: Tom Tromey <tom@tromey.com>
Date: Mon, 8 Mar 2021 07:27:57 -0700
Subject: [PATCH] Introduce unop_cast_operation

This adds class unop_cast_operation, which implements UNOP_CAST.

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

	* expop.h (class unop_cast_operation): New.
	* ax-gdb.c (unop_cast_operation::do_generate_ax): New method.
---
 gdb/ChangeLog |  5 +++++
 gdb/ax-gdb.c  | 10 ++++++++++
 gdb/expop.h   | 28 ++++++++++++++++++++++++++++
 3 files changed, 43 insertions(+)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index c260f04e48..8d1bbf028a 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2021-03-08  Tom Tromey  <tom@tromey.com>
+
+	* expop.h (class unop_cast_operation): New.
+	* ax-gdb.c (unop_cast_operation::do_generate_ax): New method.
+
 2021-03-08  Tom Tromey  <tom@tromey.com>
 
 	* expop.h (class assign_modify_operation): New.
diff --git a/gdb/ax-gdb.c b/gdb/ax-gdb.c
index f81e5b9ad2..84887da524 100644
--- a/gdb/ax-gdb.c
+++ b/gdb/ax-gdb.c
@@ -2514,6 +2514,16 @@ unop_sizeof_operation::do_generate_ax (struct expression *exp,
   value->type = builtin_type (ax->gdbarch)->builtin_int;
 }
 
+void
+unop_cast_operation::do_generate_ax (struct expression *exp,
+				     struct agent_expr *ax,
+				     struct axs_value *value,
+				     struct type *cast_type)
+{
+  std::get<0> (m_storage)->generate_ax (exp, ax, value,
+					std::get<1> (m_storage));
+}
+
 void
 unop_memval_operation::do_generate_ax (struct expression *exp,
 				       struct agent_expr *ax,
diff --git a/gdb/expop.h b/gdb/expop.h
index 93af40d959..abd5f64fda 100644
--- a/gdb/expop.h
+++ b/gdb/expop.h
@@ -1836,6 +1836,34 @@ protected:
     override;
 };
 
+/* A type cast.  */
+class unop_cast_operation
+  : public maybe_constant_operation<operation_up, struct type *>
+{
+public:
+
+  using maybe_constant_operation::maybe_constant_operation;
+
+  value *evaluate (struct type *expect_type,
+		   struct expression *exp,
+		   enum noside noside) override
+  {
+    return std::get<0> (m_storage)->evaluate_for_cast (std::get<1> (m_storage),
+						       exp, noside);
+  }
+
+  enum exp_opcode opcode () const override
+  { return UNOP_CAST; }
+
+protected:
+
+  void do_generate_ax (struct expression *exp,
+		       struct agent_expr *ax,
+		       struct axs_value *value,
+		       struct type *cast_type)
+    override;
+};
+
 } /* namespace expr */
 
 #endif /* EXPOP_H */
-- 
2.34.1