Implement C++ cast operations

This adds class cxx_cast_operation, which is used to implement the C++
dynamic_cast and reinterpret_cast operations.

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

	* expop.h (cxx_cast_ftype): New typedef.
	(cxx_cast_operation): New template.
	(dynamic_cast_operation, reinterpret_cast_operation): New
	typedefs.
This commit is contained in:
Tom Tromey 2021-03-08 07:27:57 -07:00
parent 292382f47e
commit d9ad79d880
2 changed files with 41 additions and 0 deletions

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@ -1,3 +1,10 @@
2021-03-08 Tom Tromey <tom@tromey.com>
* expop.h (cxx_cast_ftype): New typedef.
(cxx_cast_operation): New template.
(dynamic_cast_operation, reinterpret_cast_operation): New
typedefs.
2021-03-08 Tom Tromey <tom@tromey.com>
* expop.h (class unop_cast_type_operation): New.

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@ -1895,6 +1895,40 @@ class unop_cast_type_operation
override;
};
typedef value *cxx_cast_ftype (struct type *, value *);
/* This implements dynamic_cast and reinterpret_cast. static_cast and
const_cast are handled by the ordinary case operations. */
template<exp_opcode OP, cxx_cast_ftype FUNC>
class cxx_cast_operation
: public maybe_constant_operation<operation_up, operation_up>
{
public:
using maybe_constant_operation::maybe_constant_operation;
value *evaluate (struct type *expect_type,
struct expression *exp,
enum noside noside) override
{
value *val = std::get<0> (m_storage)->evaluate (nullptr, exp,
EVAL_AVOID_SIDE_EFFECTS);
struct type *type = value_type (val);
value *rhs = std::get<1> (m_storage)->evaluate (type, exp, noside);
if (noside == EVAL_SKIP)
return eval_skip_value (exp);
return FUNC (type, rhs);
}
enum exp_opcode opcode () const override
{ return OP; }
};
using dynamic_cast_operation = cxx_cast_operation<UNOP_DYNAMIC_CAST,
value_dynamic_cast>;
using reinterpret_cast_operation = cxx_cast_operation<UNOP_REINTERPRET_CAST,
value_reinterpret_cast>;
} /* namespace expr */
#endif /* EXPOP_H */