[PATCH 109/203] Introduce decltype_operation

Tom Tromey
2021-01-01T21:48:45Z

This adds class decltype_operation, which implements OP_DECLTYPE.

gdb/ChangeLog
2021-01-01 Tom Tromey <tom@tromey.com>

* expop.h (class decltype_operation): New.
---
gdb/ChangeLog | 4 ++++
gdb/expop.h | 47 +++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 51 insertions(+)

diff --git a/gdb/expop.h b/gdb/expop.h
index 502ad71d067..ba107f10ba0 100644
--- a/gdb/expop.h
+++ b/gdb/expop.h
@@ -1459,6 +1459,53 @@ class typeof_operation
{ return OP_TYPEOF; }
};

+/* Implement 'decltype'. */
+class decltype_operation
+ : public maybe_constant_operation<operation_up>
+{
+public:
+
+ using maybe_constant_operation::maybe_constant_operation;
+
+ value *evaluate (struct type *expect_type,
+ struct expression *exp,
+ enum noside noside) override
+ {
+ if (noside == EVAL_SKIP)
+ return eval_skip_value (exp);
+ else if (noside == EVAL_AVOID_SIDE_EFFECTS)
+ {
+ value *result
+ = std::get<0> (m_storage)->evaluate (nullptr, exp,
+ EVAL_AVOID_SIDE_EFFECTS);
+ enum exp_opcode sub_op = std::get<0> (m_storage)->opcode ();
+ if (sub_op == BINOP_SUBSCRIPT
+ || sub_op == STRUCTOP_MEMBER
+ || sub_op == STRUCTOP_MPTR
+ || sub_op == UNOP_IND
+ || sub_op == STRUCTOP_STRUCT
+ || sub_op == STRUCTOP_PTR
+ || sub_op == OP_SCOPE)
+ {
+ struct type *type = value_type (result);
+
+ if (!TYPE_IS_REFERENCE (type))
+ {
+ type = lookup_lvalue_reference_type (type);
+ result = allocate_value (type);
+ }
+ }
+
+ return result;
+ }
+ else
+ error (_("Attempt to use a type as an expression"));
+ }
+
+ enum exp_opcode opcode () const override
+ { return OP_DECLTYPE; }
+};
+
} /* namespace expr */

#endif /* EXPOP_H */
--
2.26.2