[PATCH 120/203] Introduce unop_cast_type_operation

Tom Tromey
2021-01-01T21:48:53Z

This adds class unop_cast_type_operation, which implements
UNOP_CAST_TYPE.

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

* expop.h (class unop_cast_type_operation): New.
* ax-gdb.c (unop_cast_type_operation::do_generate_ax): New
method.
---
gdb/ChangeLog | 6 ++++++
gdb/ax-gdb.c | 12 ++++++++++++
gdb/expop.h | 31 +++++++++++++++++++++++++++++++
3 files changed, 49 insertions(+)

diff --git a/gdb/ax-gdb.c b/gdb/ax-gdb.c
index 84887da524f..e0970e87d68 100644
--- a/gdb/ax-gdb.c
+++ b/gdb/ax-gdb.c
@@ -2661,6 +2661,18 @@ assign_modify_operation::do_generate_ax (struct expression *exp,
"may not assign to it"), name);
}

+void
+unop_cast_type_operation::do_generate_ax (struct expression *exp,
+ struct agent_expr *ax,
+ struct axs_value *value,
+ struct type *cast_type)
+{
+ struct value *val
+ = std::get<0> (m_storage)->evaluate (nullptr, exp,
+ EVAL_AVOID_SIDE_EFFECTS);
+ std::get<1> (m_storage)->generate_ax (exp, ax, value, value_type (val));
+}
+
}

/* This handles the middle-to-right-side of code generation for binary
diff --git a/gdb/expop.h b/gdb/expop.h
index 664812aec19..9102f2bb66d 100644
--- a/gdb/expop.h
+++ b/gdb/expop.h
@@ -1853,6 +1853,37 @@ class unop_cast_operation
override;
};

+/* A cast, but the type comes from an expression, not a "struct
+ type". */
+class unop_cast_type_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);
+ return std::get<1> (m_storage)->evaluate_for_cast (value_type (val),
+ exp, noside);
+ }
+
+ enum exp_opcode opcode () const override
+ { return UNOP_CAST_TYPE; }
+
+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 */
--
2.26.2