Introduce internalvar_operation

This adds class internalvar_operation, which implements
OP_INTERNALVAR.

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

	* expop.h (class internalvar_operation): New.
	* ax-gdb.c (internalvar_operation::do_generate_ax): New method.

1 files changed, 32 insertions, 0 deletions

diff --git a/gdb/expop.h b/gdb/expop.h
index 44098b8..d143815 100644
--- a/gdb/expop.h
+++ b/gdb/expop.h
@@ -649,6 +649,38 @@ public:
   { return true; }
 };
 
+class internalvar_operation
+  : public tuple_holding_operation<internalvar *>
+{
+public:
+
+  using tuple_holding_operation::tuple_holding_operation;
+
+  value *evaluate (struct type *expect_type,
+		   struct expression *exp,
+		   enum noside noside) override
+  {
+    return value_of_internalvar (exp->gdbarch,
+				 std::get<0> (m_storage));
+  }
+
+  internalvar *get_internalvar () const
+  {
+    return std::get<0> (m_storage);
+  }
+
+  enum exp_opcode opcode () const override
+  { return OP_INTERNALVAR; }
+
+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 */